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But Alison Griffith and Dorothy Smith , in an institutional ethnographic study of mothering discourse, show how organizations such as schools depend on the expected performance of mothering work; teachers cannot teach unless mothers get children to school on time, and the kind of teaching they can do is shaped by what children have already learned, a product at least in part of parental efforts that may vary considerably from one neighborhood to another.
These observations suggest that the alignment of some households but not others with the coordinative logics of other institutions may be a primary mechanism for the reproduction of inequalities. The institutional ethnographic approach can provide distinctive contributions to analyses of economic restructuring and neoliberal governance.
In the next section, I provide an overview of economic transformation in the past half-century, pointing not only to what has changed but also to some of the discursive frames and associated institutional technologies through which change has been discussed and managed. The ensemble of activities and processes we call the economy is always in flux, and capitalist economies continually change as institutional actors seek new forms of profit making.
Yet we can identify periods of relative stability, achieved through state management of the economy, and significant moments of change, when the interlocking arrangements of an entire regime of accumulation shift. Regulation theory provides a way of locating and specifying these shifts Brodie ; our approach is related but focuses on how such restructuring is accomplished on the ground.
Contemporary discourses of a New Economy mark such a period of restructuring; we argue that, in addition to naming changes, these discourses also demand and constitute change. Since the s, neoliberal political and economic theorizing has gained ascendancy in Western and other nations Harvey ; its ideas provide the overarching discourses that now most forcefully explain past and present changes and also orchestrate state and individual responses.
DeVault and efficient ways to organize human life. Who works? A discourse of work and dependency. Labor struggles through the nineteenth century brought a twentieth-century industrial compromise in work arrangements that scholars have labeled Fordism Gottfried , emphasizing long-term employment and a family household that would sustain and reproduce workers: the male worker would receive a family wage, set high enough for him to support a homemaker wife.
Though the realities never matched this model, state policies evolved around such a regime, providing public services to support these business enterprises and a modest safety net to patch up the caretaking arrangements based in family households. This Fordist regime began to crumble in the aftermath of the Second World War as capitalists began to organize their enterprises globally rather than nationally, seeking new efficiencies by using cheaper labor.
The resulting changes, labeled deindustrialization in North America, have chipped away at the traditional jobs of the male breadwinner and brought many more former housewives into paid labor.
As Nancy Naples has shown in an analysis of the congressional hearings that led up to these changes, this discourse identified the good mother as one who works to support her children and the welfare-reliant mother at home as dependent, with a strongly negative moral judgment attached.
Paid work, in these accounts, is presented as the basis for an ideal of selfsufficiency and thus for full inclusion in social life—a worthy, empowering activity that makes a good parent.
Ironically, many of the affluent women workers who are taken as self-sufficient have achieved that status by hiring and relying on low-paid immigrant domestic and careworkers see Ehrenreich and Hochschild ; Hondagneu-Sotelo The architects of U. Similarly, large employers seeking to attract and retain highly skilled workers recognize that workers who lack a stay-at-home spouse often need such assistance, and they have begun to invent a varied array of new benefits and services to address those needs.
Yet, such needs are construed in policy frameworks as temporary and exceptional, rather than ordinary. And, despite the common needs of these different groups of workers, policies for welfare recipients and higher-wage workers have developed along quite separate tracks and, as Randy Albelda observes, are rarely considered side by side. Discourses of dependency resonate even more profoundly for people with disabilities.
Marta Russell points out that the transition from feudal to industrial economies freed people from one form of political domination but also required those without wealth to find work, beg, or perish.
She suggests that the then-new industrial economy brought into consciousness the idea of disability and points out that, since that time, disability has been defined at least in part as in U. But if paid work becomes the key to social inclusion, the value of human life seems to be defined by the ability to meet the procrustean demands of paid jobs Wendell Constructions of competition and skill. Economic ideologies typically feature the economy as an organismic entity, developing according to its own logic; in these discourses, people are viewed as living at the mercy of its demands.
The very phrase New Economy has served to call on individuals to change themselves, and the notion of skill—always a political matter Jackson and Jordan —has been central to these processes. DeVault new and higher-level skills than were required in the past. The level and type of skill associated with a national population is seen as key to attracting employers who will offer particular kinds of jobs, and there is a hierarchy of jobs—labeled good and bad ones V. Smith —to match a constructed hierarchy of skills.
These paradoxical discourses involve both an individualizing rhetoric and one that erases and homogenizes individuals. These discourses promote education and training, giving rise to a great array of trainings that offer impressive certificates but that may or may not lead to sustainable employment Lafer , and they shape the kinds of training on offer, as programs are increasingly designed in consultation with those identified as business-community stakeholders Folbre ; Grahame ; Jackson , On the other hand, employers seeking a workforce rely on constructions that associate skills with particular groups—not a new strategy but one that organizes and justifies new developments.
For example, garment-industry outsourcers now explain that certain sewing skills can no longer be found in North America but exist only in countries where wage levels are conveniently low Collins Employers both see and cultivate particular inclinations and capacities in local workforces Salzinger , and states develop economic strategies responsive to those constructions Alexander ; Banerjee this volume.
These strategies produce global labor markets with consequences for all workers, even as they mark and rely on racialized differences. Fiscal discipline: Privatization and accountability. Another strand of neoliberal economic ideology emphasizes the efficiency of the market.
These policies are introducing profound changes in the national infrastructures of collective responsibility that previously helped—however unevenly—to support and sustain a workforce. Work lives, whether in public- or private-sector workplaces, are inextricably bound to public-sector services and supports. In the Fordist industrial regime, the public welfare state—including not only public assistance and social security but also housing subsidies and access to public utilities, universal education, and a public health system—has been critical for the reproduction of labor.
As restructuring has proceeded, nations in the global South have been pressed toward market-oriented reforms as a condition for entering a global economy; at the same time, the industrialized nations of the North have faced the competitive pressures of that economy and rising expenditures on health and social welfare programs. A number of feminist analysts are tracking these changes, arguing that retrenchment in the welfare state increases the burden of unpaid work shouldered by women throughout the world Bakker ; Neysmith and shifts the boundaries of public and private spheres Brodie But in both South and North, arguments for the privatization of public-sector activities have gained increasing traction.
Overview of Chapters The authors represented here are exploring the circumstances of diverse groups of workers, all of whom are navigating the terrain of the New Economy sketched in this essay.
Some contributors are longtime practitioners of institutional ethnography, while others, engaged in more conventional ethnographic research, joined our project in order to explore the approach; thus, some chapters present research explicitly designed as institutional ethnography, while others offer studies that contribute useful pieces to the picture without the focused look at textual technologies of an institutional ethnographic analysis.
We have stories to tell about people in specific places. The first section of the book introduces key elements in the ideologies that have developed as underpinnings of the so-called New Economy: ideologies that emphasize competitiveness, accountability, personal responsibility and work as empowerment, and a new managerialism that spreads business logic to the public sector and even the family. The first chapter, by Nancy Jackson and Bonnie Slade, begins in one high-tech Canadian workplace—the kind of enterprise often touted as promising the jobs of the future that demand new and higher skills.
They explain that competing on the basis of quality brings textualized forms of accountability; the new demand is not only that the product be right but also that the texts asserting its quality be in order. The analysis raises questions about the textual constructions of literacy that drive national and local agendas for job training; we also begin to see the reach of such practices into other arenas, such as public education and human services.
These authors explore technologies of measurement that are changing the landscape of public education, as new testing and publishing enterprises emerge to serve an international market and one can think of related trends within higher education, in efforts to standardize liberal arts curricula and assess their outcomes and in efforts to align the curricula of community and vocational colleges with the training needs of local business interests [Jackson ; McCoy ].
In both private- and public-sector workplaces, such ideologies of accountability resonate with common-sense ideas about effectiveness; in practice, however, the experience-based judgments and authority of those on the ground may be eroded in favor of abstracted representations of quality or learning.
This chapter also demonstrates how work is shifted back into the household, onto the shoulders of parents and consumers. Parents are recruited by teachers to assist with that work and guided in doing it by the commercial test-preparation enterprises that not only sustain but also profit from these regimes of accountability. Thus, an erosion of public education for children is hidden within a rhetoric of responsibility and accountability. Logics of personal responsibility and accountability are also shaping the work of local community groups, such as the one discussed by Nancy Jurik in chapter 3, which examines the establishment of a microlending program in the southwestern United States.
Local activists seeking strategies for poverty alleviation found in microenterprise development a strategy for providing support to individuals building very small businesses a theory of empowerment through work that resonated in multiple ways with dominant New Economy discourses, and that resonance made their program fundable.
They promised not only to serve the low-income clients who were also the target of welfare-to-work efforts of the era but also to do so in ways that were consistent with a bottom-line entrepreneurial logic. Once the activists began their work, however, they found that this structure of accountability pushed them toward traditional business models, rather than toward the more expansive social assistance they had envisioned.
The entrepreneurship featured in the microlending model fits neatly with the New Economy emphasis on self-sufficiency and individual empowerment through work. In that respect, it parallels the trend toward reductions in public assistance—exemplified in the s restructuring of the U.
The neoliberal theorizing behind welfare restructuring aims to push workers toward self-sufficiency, conceptualized as personal responsibility for seeking and sustaining paid employment. It relies on a logic of individualism, envisioning for the most part an unencumbered client who simply chooses to accept work that is offered or not see also Solomon, chapter 7; Scott and London, chapter 8; and Ridzi, chapter 11 this volume.
In much the same way, the microlending approach envisions an entrepreneur who need only apply wise business practices to succeed, focusing only minimal attention on structural obstacles or the competing pressures of caring for others.
Self-sufficiency is a key term in the new policy discourses, but it is also a malleable notion, applied unevenly in ways that hide some dependencies and highlight others. DeVault progressive disability policy. Several decades of disability-rights activism have established principles of access and inclusion, and the right of access to work has been seen as a key dimension of social inclusion.
But movement activists have envisioned participation with appropriate supports and the understanding that everyone needs assistance from others. By contrast, the neoliberal thinking behind welfare retrenchment aims to push workers into the labor force with little regard for their desires or the kinds of support that facilitate genuine inclusion. The chapters in Part I make visible a logic of market-based competition and personal accountability.
Workers and companies, students and teachers, clients and the organizations that serve them—all are seen as necessarily in competition with others. Given such an account, employers can argue that they simply cannot afford to take responsibility for workers, and states can insist on belt-tightening fiscal reforms. They are not only making that argument but also developing increasingly sophisticated managerial tools for measuring and monitoring outcomes and bringing expenditures under closer scrutiny.
Such institutional technologies are changing the bases for organizational decision making and often justify organizational shedding of responsibility for employees Acker Thus, discourses that emphasize a global market-based competitiveness and accountability set the stage for insisting that workers survive on their own, making do as best they can.
The two sections that follow trace out, in various ways, how the key terms of these ideologies are crafted into text-based state and managerial strategies that organize particular sites of work and mobilize labor within and across national borders. Two chapters examine the incorporation of immigrant labor in the United States. And both analyses illustrate that texts are activated, in complex and sometimes contradictory ways, not only by those in positions of power but also by those subject to regimes of rule.
She also demonstrates that, while the visa is a particularly determinative text—one has it or not, enters or is barred—its power to shape the daily lives of workers comes in the way it is activated in a sequence of mediating organizations. And IT workers themselves learn the terms of H1-B life and take up its challenges, seeking their own work in the United States, taking on more and more of the burdens of the flexibility that benefits their multiple employers.
Ironically, their skill and agency are knitted into a web of exploitation. But a close analysis illustrates the uneven ways that employers, state agencies, and other community residents include and exclude them. Legal permission to work and even U. From the schools and parks where young people gather to grocery stores and churches, it is daily activity that includes and excludes these new residents.
And while some of those processes are interpersonal ones, many interactions between longer-term residents and newcomers are shaped by the policies and texts of state and community governance—by the provision of English-language instruction and interpreter services, by access to housing and recreational facilities, by practices of local law enforcement, and so on.
Racialized differences related to descent and citizenship are woven into labor and state strategies to construct groups that can be positioned as outside the scope of employer or public-sector responsibility. But one can also see an emphasis on personal responsibility within the domestic labor markets of the United States and other postindustrial economies. Paid work has come to be seen as desirable for nearly everyone, with little regard for other responsibilities they may shoulder Fraser and Gordon DeVault The current promotion of paid employment over caregiving appears in starkest form in the United States in the restructuring of public assistance for low-income mothers, who are increasingly expected to move into the labor force.
The restructuring that established the TANF program— making assistance time limited and linking it to job seeking for all those deemed employable—has evolved in somewhat different local forms within a basic legislative framework and no doubt will continue to change over time.
Indeed, the policymakers who designed the program have been especially concerned to avoid subversion of program goals by front-line workers, and new technologies of accountability and performance monitoring are being brought into this realm in order to track and control implementation Ridzi In chapter 7, Brenda Solomon discusses her study of job training for nursing assistants early in the development of the welfare-to-work programs.
The program she analyzes was presented to young, low-income mothers as one that offered skill development that would move them toward economic independence; it was also closely tied to labor needs in the local small-town economy, preparing them for difficult, low-wage jobs at the local nursing home. Limiting benefits seems a simple idea— likely understood by many policymakers as a kind of tough-love spur to self-sufficiency.
But the detailed ethnographic accounts provided in this chapter reveal that these text-based versions of safety-net support are insufficient in at least some cases—sometimes with devastating results.
Some who reach the time limit find that they must rely on parents or partners with whom they have violent histories. The stark demand for self-sufficiency may seem reasonable in the textual world of policy; in the lived world of clients, it looks like an abandonment of any collective responsibility to assist vulnerable citizens. Those in jobs that are more secure are insulated from some of the pressures of economic restructuring, but they may feel its effects in subtler ways.
In the professions, work has been controlled historically through the training and ethical injunctions of the field; personal responsibility for managing and monitoring work effort has been built into the professional role.
As in other jobs, however, professionals are expected to devote themselves to work, performing as if they have no other, mundane responsibilities and, historically, many professional men have relied on wives to attend to other obligations of sustenance and care for others. The last chapter in this section chapter 10 provides a tentative look at some of the issues of support for workers with disabilities. The students she studied were enrolled in one of only a few U.
The students knew their own capacities and the kinds of assistance they could use most effectively, and they worked hard to explain and negotiate such assistance. DeVault These chapters introduce us to people navigating new demands and opportunities. These analyses display the two-sided character of such bits of text Rankin and Campbell : they operate both to organize individual activity and to provide official accounts that travel elsewhere, in forms worked up for management and decision making.
The woman who manages to complete the training program is deemed employable, regardless of her other responsibilities; the student who sits through an unsatisfactory internship is thought to have gained work experience; and so on.
The final section focuses on these managerially oriented modes of knowing work and workers, in particular the frameworks of accountability that have developed in the public sector in an era of budgetary scrutiny. It takes us further into the sites of institutional activity that operate the machinery of accountability, considering front-line sites of program delivery and the managerial oversight of these kinds of state support.
In chapter 11, Frank Ridzi uses a county appeals process as a point of entry to understanding new approaches in two U. In both programs, clients and caseworkers develop formal plans for support, and those texts are extremely consequential. Such programs do seem to give clients more autonomy than they may have had in the past. In practice, however, this system often puts them at odds with caregivers they depend on and gives them all the difficult choices that typically face managers of low-income workers.
But that straightforward notion produced a complex and ultimately wasteful web of activities, as administrators and school personnel hurried to establish the most favorable baseline budget levels they could in a competitive funding environment.
One might, of course, read this account simply as the kind of local subversion program managers have worried about as school staff try to game the system. I suggest, however, that the story also points to the kinds of problems that often arise when objectified modes of knowing students are substituted for the more grounded and particular knowing of the teachers, parents, and professionals who spend time with children. These are the kinds of dilemmas that produce front-line subversion and that often leave front-line workers feeling puzzled and demoralized as they observe their well-intentioned efforts leading in directions they did not intend.
She traces one of many ways that provincial government in British Columbia has relied on the principles of new public management to reduce welfare expenditures. As in the United States Ridzi, chapter 11 , payments for social services such as home support are increasingly bundled into block-grant funding to states and provinces, which then contract out for services.
DeVault collect continuity statistics. In the textualized version of restructuring, those with mandated responsibility to provide services can meet a textual standard of accountability, while not knowing what actually happens when a particular provider meets an individual client—in this case, when Teresa needs to lift Fred from bed to toilet.
As Campbell shows, such concrete moments of need and assistance are organized in multiple sites of ruling and justified through the conceptual currencies of the time. The consequences of change unfold in the spaces we all occupy daily—they are visible around us—but the motors and mechanisms of change are more distant.
Institutional ethnography can bring those technologies of change more clearly into view—a first step toward considering how work and life might be differently organized.
In the concluding chapter, I say more about how the method might be used to those ends. Note 1. Each analysis then traces out and explores threads of the ruling relations that have been crafted to align local activity with the sometimes contradictory institutional discourses emerging elsewhere; these include discourses of competitiveness; accountability and efficiency; and individual empowerment and inclusion achieved through participation in economic activity.
The conceptual currencies introduced in these analyses appear throughout the book, though in different forms that adapt them to particular institutional realms. They work, in part, through their double character Rankin and Campbell , which can recruit local actors to a reorganization of consciousness and thereby align their activity with ruling agendas.
Our analyses call attention to these conceptual currencies and examine, in some detail, how they aim at such alignments with managerial goals in particular cases and sites. Quality is increasingly defined textually, producing an additional layer of work. The analysis links the discussions of policymakers addressing an ostensible crisis of literacy and the ways that workers manage—and are managed by—these new demands for text-based accountability.
The juxtaposition of the policy discourse with the view of texts-in-use on the shop floor suggests that supposed problems of literacy may often be not problems of individual skill so much as perverse effects of textually mediated production and a flexible labor regime. Many jobs are changing, and mostly not for the better; they are often part-time, more precarious, with lower wages and fewer benefits.
At the same time, even such arguably bad jobs are said to involve higher skills and thus new requirements for employees. We argue that framing the issues this way conceals critical processes of organizational restructuring that are changing the nature and meaning of literacy at work. The centrality of these texts to systems of work intensification and performance monitoring can foster fear, avoidance, or resistance among employees.
Thus, paperwork is often a site of struggle; when it does not get done, complaints about literacy are usually not far behind. But closer examination of these troubles shows that they are often not about the functional skill levels of individuals but rather about changes in the social relations of work. The concept of literacy has come to stand for this complex textual relation between the demands of powerful institutions and the lives of individuals.
Here we will explore these dynamics in a manufacturing environment, but similar issues will be familiar to workers in service, health, retail, and many other workplaces in both the private and the public sectors. This essay speaks in two voices, based on the experiences of the two authors. In the first half of the paper, Nancy draws on accounts of workplace change found in social studies of work, particularly analyses of lean production and quality assurance, to situate an understanding of workplace literacy within a broader picture of widespread changes in the organization of work.
She argues that everyday demands of reading and writing are increasingly embedded in a web of textual relations that are complex and highly contested. She takes us onto the shop floor to examine the organization and implications of everyday literacy practices in this environment. Literacy: Discourse of Crisis, Danger, and Blame A critical perspective on the meaning and uses of the concept of literacy is far from new in academic life.
There is a long tradition of critical studies showing how the concept of literacy has been used in various ways across the centuries to manage populations for the benefit of powerful interests: the church of the Middle Ages, or the industrialists of the early twentieth century Graff ; Hautecoeur ; Larson There is also a critical literature on the social construction of skill, written from feminist, labor, and other critical perspectives, that shows how skill labels have been used historically to organize categories of privilege and exclusion that reproduce hierarchies of gender, race, and other dimensions of difference Cockburn ; Connell ; deWolff ; Galabuzi ; Green ; Jackson ; Slade and Mirchandani Curiously, these critical analyses of skill categories have rarely been connected to the notion of literacy.
Indeed, over the past decade or so, the principal analyses of adult literacy have come not from academics at all, or even from community advocates as in past, but rather from employer groups, business councils, and other labor-market and economic think tanks.
Under pressure from the business community, national governments of many political stripes have begun to pay more attention to literacy. The objective of this survey process is to measure and profile literacy levels among the working-age population in more than thirty countries across the world. Results from these surveys have caught the attention of governments across the industrialized world, particularly the claim that large portions of the working-age populations do not have adequate literacy levels to support everyday life and work.
Depending on the country and which iteration of the surveys is cited, between one-third and more than two-thirds of adult populations in countries surveyed1 are said to lack the minimum skill level Level 3 considered by experts to be suitable for coping with the increasing demands of the emerging knowledge society and the information economy OECD and Statistics Canada There have been many controversies among experts about the methodology, reliability, and meanings of the findings of these surveys Sticht a, b.
Perhaps the point that gained the most attention was the large disparity reported between measured performance on a set of taskbased test items and the views about performance ability expressed in the self-assessment portion of the survey. Respondents were asked how well their reading, writing, and numeracy skills met the demands of their daily lives and work. Quite consistently, adults believed their own skills to be much higher than their measured performance. Other contrasting reports have long been reported elsewhere in the academic literature Prinsloo and Breier ; Darville and are familiar to literacy practitioners.
These anomalies in survey results have produced quite different reactions among some government officials. This is very dangerous! But, for our purposes in this essay, this talk of danger and blame offers not an explanation but more puzzling data. In the following pages, we aim to shed light on this puzzle by looking first at what the literature can tell us about changing uses of text at work and then by exploring a concrete example of an electronics manufacturing workplace.
High-Performance Work Volumes have been written in the past two decades about workplace restructuring, revealing a sea change in the philosophy of management for workplaces of all kinds, both private- and public-sector. Achieving this standard depends heavily on prescribed use of text, either paper or electronic, by front-line workers. A second and closely related aspect of high-performance production is continuous improvement CI.
Like quality assurance, CI is a highly technical practice involving the systematic use of an ongoing cycle of planning, executing, checking, and refining operations to improve efficiencies and to eliminate waste in all aspects of the production process.
Data come from many sources, including the most routine use of charts, checklists, and logbooks, sometimes computerized, as part of the daily work tasks of employees in all kinds of workplaces. Until the s, production environments often involved very little paperwork. Production control was exercised through an oral culture of supervision. But today, all that has changed. Shop-floor workers commonly see the paperwork as an add-on and a second priority, while for senior managers and quality assurance experts, the data—in the form of paper or electronic text—are increasingly the form of work that counts.
The texts increasingly stand in for the product and mediate business relationships through real-time and just-in-time communications between suppliers and customers. Thus, the use of text, electronic or paper, in this setting is inseparable from the exercise of managerial power.
She shows us how the demands of reading and writing in this setting are embedded in a textual organization of work that is complex and highly contested.
However, as we continued our dialogue about my work in the plant, we discovered that texts were profoundly important, both to understanding the nature of the work and to identifying my frustrations with my job.
Here I will try to make those tensions visible. For seven years, I worked in a large, global, ISOregistered electronics contract manufacturing company. I was one of approximately fifty surface mount technology SMT team leaders in the plant whose job was to lead a small team of workers through the first manufacturing step in the production of electronic circuit boards, such as memory cards and motherboards.
The physical work of making circuit boards was relatively straightforward, since the processes for each machine and each product were documented in manufacturing instructions MIs ; although there were wide variations in the types of products that we built, the process itself was highly prescribed. All approved procedures for each stage of the production needed to be explicitly documented. The MIs, for example, contained product-specific process steps, including details on which parts should be on the board, how much solder paste should be applied, and how to handle the boards.
At the beginning of each shift, my first responsibility was to check the production board to find out which product we were building. My second task was to print all the relevant MIs to ensure that the team had the most current set of instructions.
An owner of a document was the person, usually a process engineer, who was responsible for the correct maintenance of the document in compliance with ISO. As team leader, it was my responsibility to ensure that the team was using the correct revision number of the document; this requirement meant that most team leaders printed a new set of documents each shift just to be safe.
In theory, we were allowed to do only what was detailed in the MI; in practice, there were often more effective ways to get the work done. Yet, if we were audited by a quality specialist or internal ISO auditor and asked why we were doing something in particular, we would need to be able to show the relevant section of the appropriate document to justify our actions.
These documentary requirements were essential in order for the plant to maintain the ISO certification. Thus, documents governed our work both by defining the acceptable range of our actions and by curbing our discretion.
The SMT line process involved the mechanical application of solder paste on a circuit board, the mechanical placement of electronic components on top of the solder paste, and the thermal cycling of the board in a fifty-foot oven to melt and solidify the solder paste. As the components were tiny some measured 0.
A long conveyer belt transported the circuit board from operation to operation. Part of that work was to record machine data from each step of the process in logbooks; as I reflect on my experience, this activity turned out to be central to my experience of frustration in the job. On the assembly line, there were four paper logbooks for solder paste measurements, to document when new parts were added to the placement machines and to record the results of the weekly oven profile test.
These data were used to track manufacturing problems back to the specific employee. Production demands conflicted with these requirements for recording the process, but, as team leader, I was held accountable for both tasks. I was usually able to keep on top of the required paperwork for the team leader; however, checking that the logbooks had been properly filled in by the contract workers at the end of each shift was something that I never had time for.
My attitude toward what counted as real work was shaped by middle-management actions that clearly sent the message that meeting production targets was our main priority. If the team failed to meet the production targets on a shift, I, as team leader, would be questioned by my manager about what had gone wrong.
I would also have to complete a form detailing the problems we had encountered on the shift more paperwork! It was only at the time of the ISO audits that the gaps in logbooks would be noticed. When an audit was approaching, there would be a big panic about whether the documents were thorough enough to pass the audit. Each department had a quality specialist who had to ensure that the logbooks, employee training records, and all instructional documents were up to date and complete.
At audit time, these specialists had a big job on their hands. Not surprisingly, we would often have to fabricate data after the fact in order to appear to be in compliance with audit specifications. Team leaders like me learned to play the game to keep our jobs. The failure to complete logbooks was often seen by team leaders as evidence of deficiencies in the literacy abilities of individual contract workers.
Thus, to keep up with the other demands, contract workers would neglect the logbooks. Eventually, I realized there were several more layers to this story, revealing profound contradictions in the hiring practices in the plant. For example, each SMT line was operated by four workers, three of whom had expertise on only one part of the process; only I, as team leader, was trained on all of the machines. Yet I was also the only permanent employee on my team.
The other team members were employed on six-month contracts renewable three times to a maximum of eighteen months. This practice meant that skilled and experienced workers left the company on a weekly basis, resulting in constant disruption to the team. As a team leader, I wholeheartedly agreed with this goal. However, I was frustrated by the barriers to achieving it when company hiring policies and practices favored short-term contract workers.
The minimum requirement for contract positions was a postsecondary degree from any country, an acceptable score on the Test of English as a Foreign Language TOEFL , and the successful completion of a thirty-to-forty-five-minute scenario-based interview. These hiring practices ensured that the contract workers on the manufacturing floor were highly educated people with a high degree of fluency in English. Most workers were recent male immigrants to Canada, usually with more than one university degree; these hiring criteria ensured a highly literate workforce, yet the way these highly educated workers were utilized by the company suggested otherwise.
Permanent employees were equipped with individual email accounts so that they could communicate with other workers in other departments or on other shifts. We were also given training on how to create and work with documents so that we would be able to own documents and take the lead in technical problem solving at regular quality meetings.
Permanent employees were expected to be involved in cross-shift and cross-department communication and were given the tools to accomplish this.
In sharp contrast, contract workers did not have personal email accounts; they had access only to a general department email account. As a result, they lost both their individual identities as employees and any sense of privacy in communication. They were not permitted to create new documents, lead process-improvement projects, or meet with employees on other shifts or in other departments.
At the Learning Centre, they were restricted to functional training on how to fill in logbooks. In other words, the contract workers were actively excluded from the main electronic textual practices that tied together much work of the plant. In a very real sense, the value of workers to the company could be gauged by their access to such literacy practices as the ability to communicate through email, access texts, and create new work processes via text.
Exclusion from this textual realm also meant exclusion from real power in the workplace. Finally, I also came to understand the significance of the fact that the majority of these workers were people of color. In my two years as a team leader, I worked with people from all areas of the world. It was an uncomfortable experience for me, as a Canadian-born white woman with a B.
Because the majority of permanent employees in manufacturing were also white and the majority of the contract workers were people of color, there was a strange neocolonial feel to the workplace that made me uneasy.
This was not incidental, accidental, or an oversight; it was an organizational course of action central to the labor-market strategy of this large corporation. She was keenly aware that it was a form of racialized discrimination. But what did it have to do with literacy? Together we unraveled these connections.
In this setting, as in many others, the concept of literacy was at the center of a complex textual relation between the changing demands of powerful institutions and the increasingly precarious lives of individuals. Here was a group of highly literate workers who were accused of having poor literacy on the basis of how they functioned in the plant.
How they functioned, however, turned out to have little to do with individual skills or skill deficits. Instead, it was part of an organizational course of action in which some workers and not others were hired into temporary and subordinate positions and then excluded from key literacy practices in the plant. These arrangements were designed to monitor and control the work process and were justified in terms of the imperative to turn a profit on every shift.
This particular story focuses on a relation between permanent, North American—born employees and highly skilled immigrant workers of color. Indeed, as the number of highly skilled immigrants grows in many industrialized countries, creating a workforce of newcomers who are technically skilled but socially and culturally vulnerable to exclusion, the type of situation explored in this chapter may well occur more frequently. But the dynamics described here can apply not only to the situation of immigrant workers.
Such individuals may indeed encounter challenges at work and sometimes in other areas of their lives. This could be seen as a threat to the economic status of any nation in the global marketplace.
Relatedly, there may be political dangers for public officials if they are seen to be failing in their responsibility for labor force development. So the Canadian official who spoke with such alarm may have been accurately reflecting and projecting her own fears.
But her way—and the dominant way—of framing the issues collapses these economic relations into a property—and a responsibility—of individuals. Constructing illiteracy as a problem of crisis proportions is key to making it into a site of administrative action Smith a; Darville , Yet, it is revealing to note that the kind of action that is being taken most frequently in response to this issue is not to provide more literacy instruction to increase the functional levels of adults.
On the contrary, funds available for adult literacy programming are reported to be shrinking internationally, though there is widespread new investment in literacy for children Jackson a; Khan ; Sivasubramaniam ; World Bank Testing is now commonplace not only for new job applicants but also as part of compulsory certification for people who want to keep jobs they already have.
In theory, a failed test in most of these settings is said to trigger compulsory literacy instruction; in practice, since resources for instruction are scarce, the immediate impact is often exclusion from services and opportunities. Thus, while literacy may not be experienced by individuals as a problem in the routine conduct of their lives, it is being made to matter by powerful interests that have harnessed it to their own purposes. In the process, corporate interests have overtaken human interests as the centerpiece of the literacy movement.
Notes The authors wish to acknowledge funding for this research from the Canadian Networks of Centres of Excellence: The Automobile in the 21st Century.
Statement recorded in field notes by Nancy Jackson, who attended the conference. These texts have been important in tracing how my awareness developed over the year that we worked together.
The documents were more of a shield than a source of information; I found out about production changes verbally, at shift crossover, from the other team leader.
I needed that piece of paper which was often fifteen pages long to validate my actions should I be audited. My experiences in this workplace have been the impetus for my graduate research. For more detailed analysis of the deprofessionalization of immigrant women engineers in Canada, see Slade a.
This chapter examines the push for accountability in primary education and extends the idea of interinstitutional discourses that carry ruling ideas across institutional realms and national borders. They show us mothers attempting to fill in with extra tutoring where underfunded schools and overworked teachers may not be able to meet accountability demands—in much the same way that family caregivers may fill in with unpaid child-care work as lowincome mothers are pressed into the labor force Scott and London chapter 8 and Ridzi chapter 11 this volume , or with informal nursing as hospital stays are shortened Rankin and Campbell She is doing an assignment from the Open Court Reading textbook, part of the series adopted by her urban elementary school.
Also on the table is a test-preparation workbook for the secondgrade level of the CAT-6, the standardized test required by California. Each night, while she cooks dinner and after her daughter finishes her regular homework, the mother helps her daughter go through the workbook so that the young girl will be better prepared to do well on the standardized tests she will soon take. In Toronto, another child is doing a reading assignment, which is aligned to provincial curriculum standards for which a new version of a Canadian standardized test, the CAT-3,1 has been developed.
He, too, is using the Open Court Reading text and a test-preparation workbook bought from a local bookshop on the recommendation of the community center tutor. His English is coming along well, and his parents, who speak only Farsi, wish they could better help their son prepare for the upcoming tests.
These two stories are drawn from research done in Canada and the United States that explores the educational work of mothers with children in elementary school. The similarities in these stories are striking, yet they are occurring in different countries with different educational systems, different educational policies, and different school demographics.
Across national boundaries, students undertake educational work in local classrooms that has been developed by international educational publishing corporations and prepare for standardized tests required by educational policies that, across provincial and state boundaries, have strong similarities in terms of content and process.
Over the past ten years, school systems in the United States and Canada have undergone extensive restructuring, particularly in the areas of finance, accountability, standardization and testing. Regardless of, or perhaps in concert with, the standardizing practices of current educational reforms, parents and educators struggle to meet new educational goals that have been established locally in boards of education and school districts and translocally through a global educational discourse.
In our research and writing, we have been exploring how local changes in schooling are being shaped by a global discourse on educational restructuring. In particular, we are interested in the ways that educational policies frame up the issues embedded within them in such a way that the issues can be made administratively actionable.
The educational actions that flow from a policy, then, bring with them an administrative process that manages our interaction with the identified issues. Recursively, the language of the policy can be tracked back to the globalized discourse that shaped the issue in the first place. What we see in classrooms as a result of these policy mandates is a new standardized curriculum, accompanied by standardized testing and standardized reporting—the new institutional technologies of standardization and accountability.
In the different national educational contexts of Canada and the United States, internationally developed reading series, like Open Court Reading mentioned earlier, are shaping local school and family practices in similar ways Jenkins These curricula are linked to the accountability reforms in public education, particularly to standardized testing processes.
The introductory stories tell of one way that a global educational discourse embedded in the institutional technologies of standardization and accountability can appear at the kitchen tables of families with children in public school. Exploring the Terrain The institutional technologies that we are seeing in our research are not specific to educational contexts. New institutional technologies can be linked to the social and economic transformation taking place across public service institutions.
The Canadian and U. Typically, the emphasis in discussions of the changing economy has been on the transformation of the private sector. We can see this trend particularly in the human-service domains of education, health care, and social work. We suggest that current and ongoing changes to the traditionally defined public sector are important to explore in that they affect all segments of Canadian, U. Of particular interest to us are the new institutional technologies that are central to the process of transforming human-service organizations within a globalizing economy.
As the public sector is changing, these ordinary work routines are becoming ever more digitized and more similar across institutional and national boundaries.
The new institutional technologies include standardized, often computer-mediated, always textually mediated work processes that link professionals and nonprofessionals in social institutions. They provide the administrative ground on which various levels of management in a social institution can assess and coordinate action. Although institutions differ widely in their organization, contemporary social change is interinstitutional.
The new institutional technologies are changing the relationship between professionals and nonprofessionals and directly affecting the lives of those people who fall within their institutional mandate. Institutional technologies are reshaping the work and relationships of people who participate in the public sector—those who provide services and those who receive services.
Public-service institutions are actively addressing themselves to businesslike management strategies to help accommodate reductions in social spending. Indeed, it might be said that the early-twenty-first-century revolution in information and communication makes such a transformation in human services possible. Knowledge, in processable forms, has become a resource of the greatest importance for determining the most efficient course of action in health care, social services, and educational services.
Institutional technologies that harness knowledge for the purposes of planning, resource utilization, program management, and evaluation are transforming the public sector—ranging from the processes of service-delivery systems to the required expertise of practitioners.
They also create distinctive new problems. Working from informational data bases instead of from the more traditional hands-on interaction, decision making, and professional judgment means that the manifold functions of the service sector must be reconceptualized in specific ways.
Whether organizational texts are for processing people for eligibility, assessing results of programs, determining the most cost-efficient interventions, or determining whose need is greatest for placement on waiting lists, they are constructed for the purpose of decision making about the efficient deployment of human services.
Thus, knowing, in other than objective ways, has been called into question. Yet, systems that are automated and objective must continue to rely on knowledgeable people and on the experiential input of individuals themselves to keep them operating successfully. Our research is focused at this juncture—the intersection of the new institutional technologies and the actual activities of people who work in or use human-service organizations in the transforming public sector.
The professionals employed in social work, nursing, community health, and education, as well as the support workers e. So, too, their institutional work is oriented to that part of society in which women have primary care-taking responsibility—the disabled, the family, the child.
The new institutional technologies are one instance of the textually mediated conversations that permeate social institutions. As Smith , notes, texts are ubiquitous in our social world.
Texts coordinate the apparently individual but socially organized points of connection between people working in different parts of institutional complexes of activity. In the research on education and on globalization, we are struck by the unexamined, textually mediated communications that coordinate the work and understandings of people in different social sites, nations, and, indeed, globally oriented agencies.
So, too, the phenomenon often called globalization is thoroughly textualized. For example, converging educational policies are informed by theories of the market that are being taught through textbooks in M. In the international education market, universities are changing regulations and policies to admit students from other countries on the basis of educational equivalencies portrayed in school transcripts sent within educational packages.
Bilateral and multilateral trade agreements—written agreements—shape the work of government ministries that credential public and private universities. And so on. Additionally, the 2D-3dir velocity taking into account the through-plane component only was used to obtain results analogous to a free breathing 2D-1dir acquisition.
The measurement of fluid velocity by encoding it in the phase of a magnetic resonance imaging MRI signal could allow the discrimination of the stationary spins signals from those of moving spins. This results in a wide variety of applications i.
The work presented in this paper is a theoretical analysis of some novel methods for multiple fluid velocity encoding in the phase of an MRI signal. These methods are based on a tripolar gradient TPG and can be an alternative to the conventional methods based on a bipolar gradient BPG and could be more suitable for multiple velocity encoding in the phase of an MRI signal.
Gender differences in response to cold pressor test assessed with velocity-encoded cardiovascular magnetic resonance of the coronary sinus. Gender-specific differences in cardiovascular risk are well known, and current evidence supports an existing role of endothelium in these differences. The purpose of this study was to assess non invasively coronary endothelial function in male and female young volunteers by myocardial blood flow MBF measurement using coronary sinus CS flow quantification by velocity encoded cine cardiovascular magnetic resonance CMR at rest and during cold pressor test CPT.
Coronary sinus flow was measured at rest and during CPT using non breath-hold velocity encoded phase contrast cine-CMR. Myocardial function and morphology were acquired using a cine steady-state free precession sequence.
At baseline, mean MBF was 0. The number of people practising recreational breath-hold diving is constantly growing, thereby increasing the need for knowledge of the acute and chronic effects such a sport could have on the health of participants. Breath-hold diving is potentially dangerous, mainly because of associated extreme environmental factors such as increased hydrostatic pressure, hypoxia, hypercapnia, hypothermia and strenuous exercise.
In this article we focus on the effects of breath-hold diving on pulmonary function. Furthermore, during a breath-hold dive, the chest and lungs are compressed by the increasing pressure of water. Rapid changes in lung air volume during descent or ascent can result in a lung injury known as pulmonary barotrauma. Factors that may influence individual susceptibility to breath-hold diving-induced lung injury range from underlying pulmonary or cardiac dysfunction to genetic predisposition.
According to the available data, breath-holding does not result in chronic lung injury. However, studies of large populations of breath-hold divers are necessary to firmly exclude long-term lung damage. Breath-Hold Diving. Breath-hold diving is practiced by recreational divers, seafood divers, military divers, and competitive athletes.
It involves highly integrated physiology and extreme responses. This article reviews human breath-hold diving physiology beginning with an historical overview followed by a summary of foundational research and a survey of some contemporary issues. Immersion and cardiovascular adjustments promote a blood shift into the heart and chest vasculature.
Autonomic responses include diving bradycardia, peripheral vasoconstriction, and splenic contraction, which help conserve oxygen. Competitive divers use a technique of lung hyperinflation that raises initial volume and airway pressure to facilitate longer apnea times and greater depths. Gas compression at depth leads to sequential alveolar collapse. Airway pressure decreases with depth and becomes negative relative to ambient due to limited chest compliance at low lung volumes, raising the risk of pulmonary injury called “squeeze,” characterized by postdive coughing, wheezing, and hemoptysis.
Hypoxia and hypercapnia influence the terminal breakpoint beyond which voluntary apnea cannot be sustained. Ascent blackout due to hypoxia is a danger during long breath-holds , and has become common amongst high-level competitors who can suppress their urge to breathe. Decompression sickness due to nitrogen accumulation causing bubble formation can occur after multiple repetitive dives, or after single deep dives during depth record attempts.
Humans experience responses similar to those seen in diving mammals, but to a lesser degree. The deepest sled-assisted breath-hold dive was to m. Factors that might determine ultimate human depth capabilities are discussed. Compr Physiol , Quantification of left to right atrial shunts with velocity-encoded cine nuclear magnetic resonance imaging.
The purpose of this study was to evaluate the ability of velocity-encoded nuclear magnetic resonance NMR imaging to quantify left to right intracardiac shunts in patients with an atrial septal defect.
Quantification of intracardiac shunts is clinically important in planning therapy. Because it is completely noninvasive, it can be used to monitor shunt volume over time.
Velocity navigator for motion compensated thermometry. Proton resonance frequency shift thermometry is sensitive to breathing motion that leads to incorrect phase differences. In this work, a novel velocity -sensitive navigator technique for triggering MR thermometry image acquisition is presented. A segmented echo planar imaging pulse sequence was modified for velocity -triggered temperature mapping.
Trigger events were generated when the estimated velocity value was less than 0. To remove remaining high-frequency spikes from pulsation in real time, a Kalman filter was applied to the velocity navigator data. A phantom experiment with heating and an initial volunteer experiment without heating were performed to show the applicability of this technique.
Additionally, a breath-hold experiment was conducted for comparison. In the volunteer experiment, a RMSE of 2. A novel velocity navigator with Kalman filter postprocessing in real time significantly improves the temperature accuracy over non-triggered acquisitions and suggests being comparable to a breath-held acquisition. The proposed technique might be clinically applied for monitoring of thermal ablations in abdominal organs. It is unknown whether a bio-behavioral index of distress intolerance, breath-holding duration, is acutely influenced increased or decreased by cannabis.
Such information may further inform understanding of the expression of psychological or physiological distress post-cannabis use. This within-subjects study examined whether smoked marijuana with 2. Controlling for baseline breath-holding duration and participant sex, THC produced significantly lower breath-holding durations relative to placebo.
There was a significant interaction of drug administration x frequency of cannabis use, such that THC decreased breath-holding time among less frequent but not among more frequent users.
Findings indicate that cannabis may be exacerbating distress intolerance via breath-holding duration. Objective measures of distress intolerance are sensitive to contextual factors such as acute drug intoxication, and may inform the link between cannabis use and the expression of psychological distress. Depth- encoded dual beam phase-resolved Doppler OCT for Doppler-angle-independent flow velocity measurement. Phase-resolved Doppler optical coherence tomography PR-D-OCT is a functional OCT imaging technique that can provide high-speed and high-resolution depth-resolved measurement on flow in biological materials.
In this paper, we proposed a novel dual-beam PR-D-OCT method to measure absolute flow velocity without separate measurement on the projection angle. Two parallel light beams are created in sample arm and focused into the sample at two different incident angles. The images produced by these two beams are encoded to different depths in single B-scan. Then the Doppler signals picked up by the two beams together with the incident angle difference can be used to calculate the absolute velocity.
We validated our approach in vitro on an artificial flow phantom with our home-built nm swept source OCT. Experimental results demonstrated that our method can provide an accurate measurement of absolute flow velocity with independency on the projection angle. It has been widely believed that tissue nitrogen uptake from the lungs during breath-hold diving would be insufficient to cause decompression stress in humans. With competitive free diving, however, diving depths have been ever increasing over the past decades.
A case is presented of a competitive free-diving athlete who suffered stroke-like symptoms after surfacing from his last dive of a series of 3 deep breath-hold dives. A literature and Web search was performed to screen for similar cases of subjects with serious neurological symptoms after deep breath-hold dives. A previously healthy y-old athlete experienced right-sided motor weakness and difficulty speaking immediately after surfacing from a breathhold dive to a depth of m.
He had performed 2 preceding breath-hold dives to that depth with surface intervals of only 15 min. The presentation of symptoms and neuroimaging findings supported a clinical diagnosis of stroke. Three more cases of neurological insults were retrieved by literature and Web search; in all cases the athletes presented with stroke-like symptoms after single breath-hold dives of depths exceeding m.
Two of these cases only had a short delay to recompression treatment and completely recovered from the insult. This report highlights the possibility of neurological insult, eg, stroke, due to cerebral arterial gas embolism as a consequence of decompression stress after deep breath-hold dives.
Thus, stroke as a clinical presentation of cerebral arterial gas embolism should be considered another risk of extreme breath-hold diving. Objective Breath-holding spells are known as benign attacks, frequencies of which decrease by the development of the autonomic nervous system. The present study aims to compare the electrocardiographic repolarization in children with breath-holding spells.
Methods In this study, QT dispersion, QTc dispersion, T peak to T end dispersion, and P wave dispersion of the twelve-lead surface electrocardiography of fifty children who had breath-holding spells were measured and compared with normal children from April to August QTc dispersion was increased in the patients with breath-holding spells Conclusion QTc dispersion was significantly increased in the patients with breath-holding spells compared to normal children and this is a sign of cardiac repolarization abnormality as well as the increased risk of cardiac arrhythmia in patients with breath-holding spells.
Sequence optimization to reduce velocity offsets in cardiovascular magnetic resonance volume flow quantification – A multi-vendor study. Purpose Eddy current induced velocity offsets are of concern for accuracy in cardiovascular magnetic resonance CMR volume flow quantification. However, currently known theoretical aspects of eddy current behavior have not led to effective guidelines for the optimization of flow quantification sequences. This study is aimed at identifying correlations between protocol parameters and the resulting velocity error in clinical CMR flow measurements in a multi-vendor study.
Methods Nine 1. Measurements were performed on a large stationary phantom. Starting from a clinical breath-hold flow protocol, several protocol parameters were varied. Acquisitions were made in three clinically relevant orientations. Additionally, a time delay between the bipolar gradient and read-out, asymmetric versus symmetric velocity encoding , and gradient amplitude and slew rate were studied in adapted sequences as exploratory measurements beyond the protocol.
Image analysis determined the worst-case offset for a typical great-vessel flow measurement. Results The results showed a great variation in offset behavior among scanners standard deviation among samples of 0.
Considering the absolute values, none of the tested protocol settings consistently reduced the velocity offsets below the critical level of 0. Using multilevel linear model analysis, oblique aortic and pulmonary slices showed systematic higher offsets than the transverse aortic slices oblique aortic 0. The exploratory measurements beyond the protocol yielded some new leads for further sequence development towards reduction of velocity offsets; however those protocols were not always compatible with the time-constraints of breath-hold.
Comparison of breathhold , navigator-triggered, and free-breathing diffusion-weighted MRI for focal hepatic lesions. To compare the breathhold , navigator-triggered, and free-breathing techniques in diffusion-weighted magnetic resonance imaging MRI for the evaluation of focal liver lesions on a 3.
Fifty-two patients 36 men, 16 women; mean age, A total of 74 lesions 50 malignant, 24 benign were evaluated.
The detection sensitivity and characterization accuracy were also compared. The ADC values of the liver and focal lesions measured using the three DWI techniques were not significantly different and showed good correlation. For lesion detection and characterization, there were no significant differences between breathhold and non- breathhold DWI.
Both breathhold and non- breathhold DWI are comparable for the detection or characterization of focal liver lesions at 3. In addition, although free-breathing and navigator-triggered DWI sequences show similar performance for 3. Hyperbaric nitrogen prolongs breath-holding time in humans. Either an increase in PaCO 2 or a decrease in PaO 2 , can affect respiratory stimulation through respiratory centers, thus influencing breath-holding time BHT.
This study was designed to determine whether and how hyperbaric air could influence BHT in comparison with hyperbaric oxygen in humans. We studied 36 healthy volunteers in a multiplace hyperbaric chamber.
BHT, pulse oximeter, and transcutaneous carbon dioxide tension were measured at 1 and 2. The prolongation of BHT in hyperbaric air is significantly greater than that in hyperbaric oxygen. Breath-holding time is significantly prolonged in hyperbaric air than it is in hyperbaric oxygen. The mechanism involves the anesthetic effect of nitrogen suppressing the suffocating feeling during breath-holding.
To present our clinical workflow of incorporating AlignRT for left breast deep inspiration breath-hold treatments and the dosimetric considerations with the deep inspiration breath-hold protocol. Patients with stage I to III left-sided breast cancer who underwent lumpectomy or mastectomy were considered candidates for deep inspiration breath-hold technique for their external beam radiation therapy.
Treatment plans were created on both free-breathing and deep inspiration breath-hold computed tomography for each patient to determine whether deep inspiration breath-hold was beneficial based on dosimetric comparison.
The AlignRT system was used for patient setup and monitoring. Dosimetric measurements and their correlation with chest wall excursion and increase in left lung volume were studied for free-breathing and deep inspiration breath-hold plans.
Deep inspiration breath-hold plans had significantly increased chest wall excursion when compared with free breathing. This change in geometry resulted in reduced mean and maximum heart dose but did not impact lung V 20 or mean dose. The correlation between chest wall excursion and absolute reduction in heart or lung dose was found to be nonsignificant, but correlation between left lung volume and heart dose showed a linear association.
It was also identified that higher levels of chest wall excursion may paradoxically increase heart or lung dose. Reduction in heart dose can be achieved for many left-sided breast and chest wall patients using deep inspiration breath-hold.
Chest wall excursion as well as left lung volume did not correlate with reduction in heart dose, and it remains to be determined what metric will provide the most optimal and reliable dosimetric advantage.
Effects of depth and chest volume on cardiac function during breath-hold diving. Cardiac response to breath-hold diving in human beings is primarily characterized by the reduction of both heart rate and stroke volume. We hypothesized that underwater re-expansion of the chest would release heart constriction and normalize cardiac function.
To this aim, 10 healthy male subjects age During the same session, all subjects were also studied at surface full-body immersion and at 5-m depth in order to better characterize the relationship of echo-Doppler pattern with depth.
In conclusion the diving response, already evident during shallow diving 5 m did not progress during deeper dives 10 m. The rapid improvement in systolic and diastolic function observed after lung volume expansion is congruous with the idea of a constrictive effect on the heart exerted by chest squeeze. Breath-holds are a readily accessible method for producing the required arterial CO2 increases but their implementation into clinical studies is limited by concerns that patients will demonstrate highly variable performance of breath-hold challenges.
This study assesses the repeatability of CVR measurements despite poor task performance, to determine if and how robust results could be achieved with breath-holds in patients. Twelve healthy volunteers were scanned at 3 T. Six functional scans were acquired, each consisting of 6 breath-hold challenges 10, 15, or 20 s duration interleaved with periods of paced breathing.
These scans simulated the varying breath-hold consistency and ability levels that may occur in patient data. Uniform ramps, time-scaled ramps, and end-tidal CO2 data were used as regressors in a general linear model in order to measure CVR at the grey matter, regional, and voxelwise level.
The intraclass correlation coefficient ICC quantified the repeatability of the CVR measurement for each breath-hold regressor type and scale of interest across the variable task performances. The ramp regressors did not fully account for variability in breath-hold performance and did not achieve acceptable repeatability ICC 0.
Further analysis of intra-subject CVR variability across the brain ICCspatial and voxelwise correlation supported the use of end-tidal CO2 data to extract robust whole-brain CVR maps, despite variability in breath-hold performance.
We conclude that the incorporation of end-tidal CO2 monitoring into scanning enables robust, repeatable. Do elite breath-hold divers suffer from mild short-term memory impairments? Repeated apneas are associated with severe hypoxemia that may ultimately lead to loss of consciousness in some breath-hold divers. Despite increasing number of practitioners, the relationship between apnea-induced hypoxia and neurocognitive functions is still poorly understood in the sport of free diving.
To shed light onto this phenomenon, we examined the impact of long-term breath-hold diving training on attentional processing, short-term memory, and long-term mnesic and executive functions.
Thirty-six men matched for age, height, and weight were separated into the following 3 groups: i 12 elite breath-hold divers EBHD , mean static apnea best time s, months mean apnea experience; ii 12 novice breath-hold divers, mean best time s, 8. We used breath-holding during inspiration as a model to study the effect of pulmonary stretch on sympathetic nerve activity. Prolonged dry apnoea: effects on brain activity and physiological functions in breath-hold divers and non-divers. The aim of the study was to investigate the effects of voluntary breath-holding on brain activity and physiological functions.
We hypothesised that prolonged apnoea would trigger cerebral hypoxia, resulting in a decrease of brain performance; and the apnoea’s effects would be more pronounced in breath-hold divers. Trained breath-hold divers and non-divers performed maximal dry breath-holdings.
Lung volume, alveolar partial pressures of O2 and CO2, attention and anxiety levels were estimated. Heart rate, blood pressure, arterial blood oxygenation, brain tissue oxygenation, EEG, and DC potential were monitored continuously during breath-holding. There were a few significant changes in electrical brain activity caused by prolonged apnoea. Brain tissue oxygenation index and DC potential were relatively stable up to the end of the apnoea in breath-hold divers and non-divers.
We also did not observe any decrease of attention level or speed of processing immediately after breath-holding. Interestingly, trained breath-hold divers had some peculiarities in EEG activity at resting state before any breath-holding : non-spindled, sharpened alpha rhythm; slowed-down alpha with the frequency nearer to the theta band; and untypical spatial pattern of alpha activity. Our findings contradicted the primary hypothesis.
Apnoea up to 5 min does not lead to notable cerebral hypoxia or a decrease of brain performance in either breath-hold divers or non-divers. It seems to be the result of the compensatory mechanisms similar to the diving response aimed at centralising blood circulation and reducing peripheral O2 uptake.
Adaptive changes during apnoea are much more prominent in trained breath-hold divers. Optimization of single shot 3D breath-hold non-enhanced MR angiography of the renal arteries.
Cardiac and navigator-gated, inversion-prepared non-enhanced magnetic resonance angiography techniques can accurately depict the renal arteries without the need for contrast administration. However, the scan time and effectiveness of navigator-gated techniques depend on the subject respiratory pattern, which at times results in excessively prolonged scan times or suboptimal image quality. A single-shot 3D magnetization-prepared steady-state free precession technique was implemented to allow the full extent of the renal arteries to be depicted within a single breath-hold.
Technical optimization of the breath-hold technique was performed with fourteen healthy volunteers. An alternative magnetization preparation scheme was tested to maximize inflow signal. Quantitative and qualitative comparisons were made between the breath-hold technique and the clinically accepted navigator-gated technique in both volunteers and patients on a 1.
The breath-hold technique provided an average of seven fold reduction in imaging time, without significant loss of image quality. Comparable single-to-noise and contrast-to-noise ratios of intra- and extra-renal arteries were found between the breath-hold and the navigator-gated techniques in volunteers.
Furthermore, the breath-hold technique demonstrated good image quality for diagnostic purposes in a small number of patients in a pilot study.
The single-shot, breath-hold technique offers an alternative to navigator-gated methods for non-enhanced renal magnetic resonance angiography. The initial results suggest a potential supplementary clinical role for the breath-hold technique in the evaluation of suspected renal artery diseases. Glide-Hurst, Carri K. Purpose: To evaluate intra- and interfraction variability of tumor and lung volume and position using a hybrid active breath-hold gating technique.
Methods and Materials: A total of repeat normal inspiration active breath-hold CTs were acquired weekly during radiotherapy for 9 lung cancer patients scans per patient. A physician delineated the gross tumor volume GTV , lungs, and spinal cord on the first breath-hold CT, and contours were propagated semiautomatically.
Intra- and interfraction variability of tumor and lung position and volume were evaluated. Tumor centroid and border variability were quantified.
Results: On average, intrafraction variability of lung and GTV centroidmore » position was 0. Increases in free-breathing tidal volume were associated with increases in breath-hold ipsilateral lung volume p breath-hold technique was reproducible within 2 mm during each fraction.
Interfraction variability of GTV position and shape was substantial because of tumor volume and breath-hold lung volume change during therapy. These results support the feasibility of a hybrid breath-hold gating technique and suggest that online image guidance would be beneficial.
Underwater study of arterial blood pressure in breath-hold divers. Knowledge regarding arterial blood pressure ABP values during breath-hold diving is scanty. It derives from a few reports of measurements performed at the water’s surface, showing slight or no increase in ABP, and from a single study of two simulated deep breath-hold dives in a hyperbaric chamber.
Simulated dives showed an increase in ABP to values considered life threatening by standard clinical criteria. For the first time, using a novel noninvasive subaquatic sphygmomanometer, we successfully measured ABP in 10 healthy elite breath-hold divers at a depth of 10 m of freshwater mfw. ABP was measured in dry conditions, at the surface head-out immersion , and twice at a depth of 10 mfw.
Underwater measurements of ABP were obtained in all subjects. Each measurement lasted s and was accomplished without any complications or diver discomfort. No significant statistical differences were found when blood pressure measurements at the water surface were compared with breath-hold diving conditions at a depth of 10 mfw. However, our results cannot be extended over environmental conditions different from those of the present study.
Harouni, Ahmed A. Purpose An external driver-free MRI method for assessment of liver fibrosis offers a promising non-invasive tool for diagnosis and monitoring of liver disease. However, MR tagging requires multiple breath-hold acquisitions and substantial post-processing. Additionally, a new method is introduced to measure heart-induced shear wave velocity SWV inside the liver.
Methods Phantom and in-vivo experiments 11 healthy subjects, and 11 patients with liver fibrosis were conducted. Reproducibility experiments were performed in seven healthy subjects. Results Peak liver strain Sp significantly decreased in fibrotic liver compared healthy liver 6.
The two measures significantly separate healthy subjects from patients with fibrotic liver. Purpose: To evaluate the feasibility of 3D single breath-hold late gadolinium enhancement LGE of the left ventricle LV using supplemental oxygen and hyperventilation and compressed-sensing acceleration.
Semi-quantitative grading of overall image quality, motion artifact, myocardial nulling, and diagnostic value was performed by consensus of two blinded observers.
Velocity encoding with the slice select refocusing gradient for faster imaging and reduced chemical shift-induced phase errors. To investigate a novel phase-contrast MRI velocity-encoding technique for faster imaging and reduced chemical shift-induced phase errors.
Velocity encoding with the slice select refocusing gradient achieves the target gradient moment by time shifting the refocusing gradient, which enables the use of the minimum in-phase echo time TE for faster imaging and reduced chemical shift-induced phase errors. Improved net forward flow agreement was measured across all vessels for slice select refocused gradient compared to flow compensated and flow encoded : aAo vs.
To evaluate the feasibility of three-dimensional 3D single breath-hold late gadolinium enhancement LGE of the left ventricle LV using supplemental oxygen and hyperventilation and compressed-sensing acceleration. Semiquantitative grading of overall image quality, motion artifact, myocardial nulling, and diagnostic value was performed by consensus of two blinded observers.
Dosimetric comparison of moderate deep inspiration breath-hold and free-breathing intensity-modulated radiotherapy for left-sided breast cancer. This study determined the dosimetric comparison of moderate deep inspiration breath-hold using active breathing control and free-breathing intensity-modulated radiotherapy IMRT after breast-conserving surgery for left-sided breast cancer.
Thirty-one patients were enrolled. One free breathe and two moderate deep inspiration breath-hold images were obtained. A field-in-field-IMRT free-breathing plan and two field-in-field-IMRT moderate deep inspiration breath-holding plans were compared in the dosimetry to target volume coverage of the glandular breast tissue and organs at risks for each patient.
The breath-holding time under moderate deep inspiration extended significantly after breathing training P breath-holding in the target volume coverage.
The volume of the ipsilateral lung in the free-breathing technique were significantly smaller than the moderate deep inspiration breath-holding techniques P breath-holding plans.
The dose to ipsilateral lung, coronary artery and heart in the field-in-field-IMRT were significantly lower for the free-breathing plan than for the two moderate deep inspiration breath-holding plans all P breath-holding plans. The whole-breast field-in-field-IMRT under moderate deep inspiration breath-hold with active breathing control after breast-conserving surgery in left-sided breast cancer can reduce the irradiation volume and dose to organs at risks.
There are no significant differences between various moderate deep inspiration breath-holding states in the dosimetry of irradiation to the field-in-field-IMRT target volume. Asystole and increased serum myoglobin levels associated with ‘packing blackout’ in a competitive breath-hold diver.
Many competitive breath-hold divers use ‘glossopharyngeal insufflation’, also called ‘lung packing’, to overfill their lungs above normal total lung capacity. This increases intrathoracic pressure, decreases venous return, compromises cardiac pumping, and reduces arterial blood pressure, possibly resulting in a syncope breath-hold divers call ‘packing blackout’.
We report a case with a breath-hold diver who inadvertently experienced a packing blackout. During the incident, an electrocardiogram ECG and blood pressure were recorded, and blood samples for determinations of biomarkers of cardiac muscle perturbation creatine kinase-MB isoenzyme CK-MB , cardiac troponin-T TnT , and myoglobin were collected.
The ECG revealed short periods of asystole during the period of ‘packing blackout’, simultaneous with pronounced reductions in systolic, diastolic, and pulse pressures. Serum myoglobin concentration was elevated 40 and min after the incident, whereas there were no changes in CK-MB or TnT. The ultimate cause of syncope in this diver probably was a decrease in cerebral perfusion following glossopharyngeal insufflation.
The asystolic periods recorded in this diver could possibly indicate that susceptible individuals may be put at risk of a serious cardiac incident if the lungs are excessively overinflated by glossopharyngeal insufflation.
This concern is further substantiated by the observed increase in serum myoglobin concentration after the event. Paced respiration with end-expiration technique offers superior BOLD signal repeatability for breath-hold studies. As a simple, non-invasive method of blood oxygenation level-dependent BOLD signal calibration, the breath-hold task offers considerable potential for the quantification of neuronal activity from functional magnetic resonance imaging fMRI measurements.
With an aim to improve the precision of this calibration method, the impact of respiratory rate control on the BOLD signal achieved with the breath-hold task was investigated. In addition to self-paced breathing, three different computer-paced breathing rates were imposed during the periods between end-expiration breath-hold blocks. The resulting BOLD signal timecourses and statistical activation maps were compared in eleven healthy human subjects.
Results indicate that computer-paced respiration produces a larger peak BOLD signal increase with breath-hold than self-paced breathing, in addition to lower variability between trials. This is due to the more significant post-breath-hold signal undershoot present in self-paced runs, a characteristic which confounds the definition of baseline and is difficult to accurately model. Interestingly, the specific respiratory rate imposed between breath-hold periods generally does not have a statistically significant impact on the BOLD signal change.
This result can be explained by previous reports of humans adjusting their inhalation depth to compensate for changes in rate, with the end-goal of maintaining homeostatic ventilation. The advantage of using end-expiration relative to end-inspiration breath-hold is apparent in view of the high repeatability of the BOLD signal in the present study, which does not suffer from the previously reported high variability associated with uncontrolled inspiration depth when using the end-inspiration technique.
The aim of this study was to assess the validity and accuracy of a commercial linear encoder Musclelab, Ergotest, Norway to estimate Bench press 1 repetition maximum 1RM from the force – velocity relationship. Twenty seven physical education students and teachers 5 women and 22 men with a heterogeneous history of strength training participated in this study.
They performed a 1 RM test and a force – velocity test using a Bench press lifting task in a random order. Mean 1 RM was Additional studies are required to determine whether accuracy is affected by age, sex or initial level. Key pointsSome commercial devices allow to estimate 1 RM from the force- velocity relationship. These estimations are valid. However, their accuracy is not high enough to be of practical help for training intensity prescription. Day-to-day reliability of force and velocity measured by the linear encoder has been shown to be very high, but the specific reliability of 1 RM estimated from the force- velocity relationship has to be determined before concluding to the usefulness of this approach in the monitoring of training induced adaptations.
Key points Some commercial devices allow to estimate 1 RM from the force- velocity relationship. Breath-hold device for laboratory rodents undergoing imaging procedures. The increased use in noninvasive imaging of laboratory rodents has prompted innovative techniques in animal handling. Lung imaging of rodents can be a difficult task because of tissue motion caused by breathing, which affects image quality.
The use of a prototype flat-panel computed tomography unit allows the acquisition of images in as little as 2, 4, or 8 s.
This short acquisition time has allowed us to improve the image quality of this instrument by performing a breath-hold during image acquisition. We designed an inexpensive and safe method for performing a constant-pressure breath-hold in intubated rodents. Initially a prototypic manual 3-way valve system, consisting of a 3-way valve, an air pressure regulator, and a manometer, was used to manually toggle between the ventilator and the constant-pressure breath-hold equipment.
The success of the manual 3-way valve system prompted the design of an electronically actuated valve system. In the electronic system, the manual 3-way valve was replaced with a custom designed 3-way valve operated by an electrical solenoid. The electrical solenoid is triggered by using a hand-held push button or a foot pedal that is several feet away from the gantry of the scanner.
This system has provided improved image quality and is safe for the animals, easy to use, and reliable. Premotor neurons encode torsional eye velocity during smooth-pursuit eye movements. Responses to horizontal and vertical ocular pursuit and head and body rotation in multiple planes were recorded in eye movement-sensitive neurons in the rostral vestibular nuclei VN of two rhesus monkeys. When tested during pursuit through primary eye position, the majority of the cells preferred either horizontal or vertical target motion.
During pursuit of targets that moved horizontally at different vertical eccentricities or vertically at different horizontal eccentricities, eye angular velocity has been shown to include a torsional component the amplitude of which is proportional to half the gaze angle “half-angle rule” of Listing’s law.
Multiple linear regression analysis revealed a significant contribution of torsional eye movement sensitivity to the responsiveness of the cells. These findings suggest that many VN neurons encode three-dimensional angular velocity , rather than the two-dimensional derivative of eye position, during smooth-pursuit eye movements. Although no clear clustering of pursuit preferred-direction vectors along the semicircular canal axes was observed, the sensitivity of VN neurons to torsional eye movements might reflect a preservation of similar premotor coding of visual and vestibular-driven slow eye movements for both lateral-eyed and foveate species.
Purpose: To study the oxygen saturation SO2 and breath-holding time variation applied active breathing control ABC in radiotherapy of tumor. And the patient monitor was used to observe the oxygen saturation SO2 variation. The variation of SO2, and length of breath-holding time and the time for recovering to the initial value of SO2 were recorded and analyzed.
And the breath-holding time shortened obviously for patients whose SO2 did not recover to normal. It is necessary to check the SO2 variation in breath training, and enough time should be given to recover SO2. We describe a clinical case study surrounding the behavioral assessment and operant treatment of, an adult with severe mental retardation who engaged in chronic breath-holding. In this clinical case, previous neurological and medical testing had ruled out biological bases for the individual’s breath-holding.
A functional behavioral assessment…. Agreement and repeatability of vascular reactivity estimates based on a breath-hold task and a resting state scan. By complementing a task-related BOLD acquisition with a vascular reactivity measure obtained through breath-holding or hypercapnia, this unwanted variance can be statistically reduced in the BOLD responses of interest.
Recently, it has been suggested that vascular reactivity can also be estimated using a resting state scan. This study aimed to compare three breath-hold based analysis approaches block design, sine—cosine regressor and CO2 regressor and a resting state approach CO2 regressor to measure vascular reactivity. We tested BOLD variance explained by the model and repeatability of the measures. Fifteen healthy participants underwent a breath-hold task and a resting state scan with end-tidal CO2 being recorded during both.
Maps and regional vascular reactivity estimates showed high repeatability when the breath-hold task was used. Repeatability and variance explained by the CO2 trace regressor were lower for the resting state data based approach, which resulted in highly variable measures of vascular reactivity. We conclude that breath-hold based vascular reactivity estimations are more repeatable than resting-based estimates, and that there are limitations with replacing breath-hold scans by resting state scans for vascular reactivity assessment.
Both CO 2 inhalation followed by hyperventilation and breath-holding have been utilized to measure cerebral vasomotor reactivity VMR but their correlation has been poorly studied and understood. A retrospective study was conducted in subjects The mean BHI was 0. Move dish and sample into the cell culture This study aimed to compare three breath-hold based analysis approaches block design, sine-cosine regressor and CO2 regressor and a resting state approach CO2 regressor to measure vascular reactivity.
Published by Elsevier Inc. Boson sampling is a problem strongly believed to be intractable for classical computers, but can be naturally solved on a specialized photonic quantum simulator. The protocol requires only one single-photon source, two detectors, and a loop-based interferometer for an arbitrary number of photons. The single-photon pulse train is time-bin encoded and deterministically injected into an electrically programmable multimode network.
The observed three- and four-photon boson sampling rates are Volumetric velocity measurements in restricted geometries using spiral sampling : a phantom study. The aim of this study was to evaluate the accuracy of maximum velocity measurements using volumetric phase-contrast imaging with spiral readouts in a stenotic flow phantom. In a phantom model, maximum velocity , flow, pressure gradient, and streamline visualizations were evaluated using volumetric phase-contrast magnetic resonance imaging MRI with velocity encoding in one extending on current clinical practice and three directions for characterization of the flow field using spiral readouts.
Results of maximum velocity and pressure drop were compared to computational fluid dynamics CFD simulations, as well as corresponding low-echo-time TE Cartesian data.
Flow was compared to 2D through-plane phase contrast PC upstream from the restriction. Results obtained with 3D through-plane PC as well as 4D PC at shortest TE using a spiral readout showed excellent agreements with the maximum velocity values obtained with CFD velocity location, as well as the accurate velocity quantification can be obtained in stenotic regions using short-TE spiral volumetric PC imaging.
Marijuana smoking: effects of varying puff volume and breathhold duration. Two studies were conducted to quantify biological and behavioral effects resulting from exposure to controlled doses of marijuana smoke.
Each study also varied levels of delta 9-tetrahydro-cannabinol marijuana cigarette content 1. Subjects smoked 10 puffs in each of six sessions; a seventh, nonsmoking session all measures recorded at the same times as in active smoking sessions served as a control.
Variations in puff volume produced significant dose-related changes in postsmoking plasma delta 9-tetrahydro-cannabinol levels, carbon monoxide boost and subjective effects e. In contrast, breathholding for 10 or 20 sec versus 0 sec increased plasma delta 9-tetrahydro-cannabinol levels but not CO boost or subjective effects. Task performance measures were not reliably influenced by marijuana smoke exposure within the dosing ranges examined. These findings confirm the utility of the controlled smoking technology, support the notion that cumulative puff volume systematically influences biological exposure and subjective effects, but cast doubt on the common belief that prolonged breathholding of marijuana smoke enhances classical subjective effects associated with its reinforcing value in humans.
Zhang, Ziheng; Dione, Donald P. A novel MR imaging technique, spatial modulation of magnetization with polarity alternating velocity encoding SPAMM-PAV , is presented to simultaneously examine the left ventricular early diastolic temporal relationships between myocardial deformation and intra-cavity hemodynamics with a high temporal resolution of 14 ms.
This approach is initially evaluated in a dynamic flow and tissue mimicking phantom. A comparison of regional longitudinal strains and intra-cavity pressure differences integration of computed in-plane pressure gradients within a selected region in relation to mitral valve inflow velocities is performed in eight normal volunteers.
Our results demonstrate that apical regions have higher strain rates 0. This pattern is reversed during the deceleration period, when the strain-rates in the basal regions are the highest 0. A positive base-to-apex gradient in peak pressure difference is observed during acceleration, followed by a negative base-to apex gradient during deceleration.
These studies shed insight into the regional volumetric and pressure difference changes in the left ventricle during early diastolic filling. Breast tumor hemodynamic response during a breath-hold as a biomarker to predict chemotherapeutic efficacy: preclinical study. Therefore, it requires a perturbation of physiological signals, such as blood flow and oxygenation.
In that sense, a few groups reported that monitoring a relative hemodynamic change during a breast tissue compression or a breath-hold to a patient can provide good contrast between tumor and nontumor. However, no longitudinal study reports the utilization of a breath-hold to predict tumor response during chemotherapy.
A continuous wave near-infrared spectroscopy was employed to monitor hemodynamics in rat breast tumor during a hyperoxic to normoxic inhalational gas intervention to mimic a breath-hold during tumor growth and chemotherapy. The reduced oxyhemoglobin concentration during inhalational gas intervention correlated well with tumor growth, and it responded one day earlier than the change of tumor volume after chemotherapy. In conclusion, monitoring tumor hemodynamics during a breath-hold may serve as a biomarker to predict chemotherapeutic efficacy of tumor.
Left ventricle changes early after breath-holding in deep water in elite apnea divers. To study by ultrasounds cardiac morphology and function early after breath-hold diving in deep water in elite athletes. Each subject performed a series of three consecutive breath-hold dives and 40 m depth. End-diastolic left ventricular LV diameter EDD and end-diastolic LV volume EDV increased significantly p breath-hold diving due to favorable changes in loading conditions relative to pre-diving, namely the recruitment of left ventricular preload reserve and the reduction in afterload.
Dark chocolate reduces endothelial dysfunction after successive breath-hold dives in cool water. The aim of this study is to observe the effects of dark chocolate on endothelial function after a series of successive apnea dives in non-thermoneutral water.
Twenty breath-hold divers were divided into two groups: a control group 8 males and 2 females and a chocolate group 9 males and 1 female. The chocolate group performed the dives 1 h after ingestion of 30 g of dark chocolate. A significant decrease in FMD was observed in the control group after the dives No differences in digital photoplethysmography and peroxynitrites were observed between before and after the dives.
Antioxidants contained in dark chocolate scavenge free radicals produced during breath-hold diving. Ingestion of 30 g of dark chocolate 1 h before the dive can thus prevent endothelial dysfunction which can be observed after a series of breath-hold dives. Validation of high temporal resolution spiral phase velocity mapping of temporal patterns of left and right coronary artery blood flow against Doppler guidewire. Temporal patterns of coronary blood flow velocity can provide important information on disease state and are currently assessed invasively using a Doppler guidewire.
A non-invasive alternative would be beneficial as it would allow study of a wider patient population and serial scanning. A retrospectively-gated breath-hold spiral phase velocity mapping sequence TR 19 ms was developed at 3 Tesla. Velocity maps were acquired in 8 proximal right and 15 proximal left coronary arteries of 18 subjects who had previously had a Doppler guidewire study at the time of coronary angiography.
Cardiovascular magnetic resonance CMR velocity -time curves were processed semi-automatically and compared with corresponding invasive Doppler data. High temporal resolution breath-hold spiral phase velocity mapping underestimates absolute values of coronary flow velocity but allows accurate assessment of the temporal patterns of blood flow. MR imaging of the human heart without explicit cardiac synchronization promises to extend the applicability of cardiac MR to a larger patient population and potentially expand its diagnostic capabilities.
However, conventional non-gated imaging techniques typically suffer from low image quality or inadequate spatio-temporal resolution and fidelity. Patient-Adaptive Reconstruction and Acquisition in Dynamic Imaging with Sensitivity Encoding PARADISE is a highly-accelerated non-gated dynamic imaging method that enables artifact-free imaging with high spatio-temporal resolutions by utilizing novel computational techniques to optimize the imaging process. In addition to using parallel imaging, the method gains acceleration from a physiologically-driven spatio-temporal support model; hence, it is doubly accelerated.
The support model is patient-adaptive, i. The proposed method is also doubly adaptive as it adapts both the acquisition and reconstruction schemes. Based on the theory of time-sequential sampling , the proposed framework explicitly accounts for speed limitations of gradient encoding and provides performance guarantees on achievable image quality.
Determination of ethane, pentane and isoprene in exhaled air–effects of breath-holding , flow rate and purified air. Exhaled ethane, pentane and isoprene have been proposed as biomarkers of oxidative stress. The objectives were to explore whether ethane, pentane and isoprene are produced within the airways and to explore the effect of different sampling parameters on analyte concentrations.
The flow dependency of the analyte concentrations, the concentrations in dead-space and alveolar air after breath-holding and the influence of inhaling purified air on analyte concentrations were investigated. The analytical method involved thermal desorption from sorbent tubes and gas chromatography. The studied group comprised 13 subjects with clinically stable asthma and 14 healthy controls. After breath-holding , no significant changes in ethane levels were observed. Pentane and isoprene levels increased significantly after 20 s of breath-holding.
Inhalation of purified air before exhalation resulted in a substantial decrease in ethane levels, a moderate decrease in pentane levels and an increase in isoprene levels. The major fractions of exhaled ethane, pentane and isoprene seem to be of systemic origin. There was, however, a tendency for ethane to be flow rate dependent in asthmatic subjects, although to a very limited extent, suggesting that small amounts of ethane may be formed in the airways.
Double-blind, placebo-controlled trial on the effect of piracetam on breath-holding spells. Breath-holding spells BHS are apparently frightening events occurring in otherwise healthy children.
The aim of this study was to evaluate the efficacy of piracetam in the treatment of breath-holding spells. Forty patients with BHS who were classified into two groups were involved in a double-blinded placebo-controlled prospective study. Piracetam was given to group A while group B received placebo. Patients were followed monthly for a total period of 4 months.
There was a significant decline of number of attacks after piracetam treatment compared to placebo p value breath-holding spells in children. Evaluation of correlation between physical properties and ultrasonic pulse velocity of fired clay samples.
The aim of this study is to establish a correlation between physical properties and ultrasonic pulse velocity of clay samples fired at elevated temperatures. Brick-making clay and pottery clay were studied for this purpose.
A commercial ultrasonic testing instrument Proceq Pundit Lab was used to evaluate the ultrasonic pulse velocity measurements for each fired clay sample as a function of temperature. It was observed that there became a relationship between physical properties and ultrasonic pulse velocities of the samples. The results showed that in consequence of increasing densification of the samples , the differences between the ultrasonic pulse velocities were higher with increasing temperature.
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Methods and Materials: A total of repeat normal inspiration active breath-hold CTs were acquired weekly during radiotherapy for 9 lung cancer patients scans per patient. The very phrase New Economy has served to call on individuals to change themselves, and the notion of skill—always a political matter Jackson and Jordan —has been central to these processes. So supplemental is one area for us to grow. Spacers and regions of sequences. Local institutional review board approval was obtained; patients or their parents gave informed consent.
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In addition, the performance of the optimum receiver depends on the receiver’s ability to compute the ISI accurately, thus providing a trade-off between receiver complexity and achievable bit error rate BER. The left coronary circulation was imaged in six healthy subjects and two patients with coronary artery disease.