Physiologic responses to arm ergometry exercise relative to age and gender

AbstractArm ergometry exercise testing is a valuable alternative method used in the evaluation and management of patients with both cardiac disease and lower limb impairment. The purpose of this study is to provide information concerning the physiologic responses of normal healthy subjects to arm ergometry relative to age and gender, which could serve as a standard for comparison. Eighty healthy subjects (age 22 to 59 years) cycled at 75 to 80 rpm (on a bicycle adapted for arm ergometry) starting at a power output of 10 W, increasing at 10 W/2 min until exhaustion.Sixty subjects were classified on the basis of age into three groups, each with 10 men and 10 women. Men achieved significantly (p < 0.001) higher power output (95 ± 25 W) and oxygen consumption (20.7 ± 3.9 ml/kg per min) than did women (56 ± 19 W and 15.5 ± 3.1 ml/kg per min, respectively). The heart rate response to total body oxygen demand during arm ergometry was significantly higher in women than in men (p < 0.001). These findings were also present when men and women of each age group were analyzed separately. Older subjects reached a significantly (p < 0.02) lower peak power output than did younger subjects although they reached a similar level of oxygen consumption.Separate regression equations for predicting oxygen consumption at each power output were formulated for men and women and validated in 20 other subjects. Small differences in measured and predicted oxygen consumption at each stage were found. These data provide additional information concerning arm ergometry testing and should prove useful in diagnostic exercise testing and cardiac rehabilitation

Design, implementation, and evaluation of parallell pipelined STAP on parallel computers

Performance results are presented for the design and implementation of parallel pipelined space-time adaptive processing (STAP) algorithms on parallel computers. In particular, the issues involved in parallelization, our approach to parallelization, and performance results on an Intel Paragon are described. The process of developing software for such an application on parallel computers when latency and throughput are both considered together is discussed and tradeoffs considered with respect to inter and intratask communication and data redistribution are presented. The results show that not only scalable performance was achieved for individual component tasks of STAP but linear speedups were obtained for the integrated task performance, both for latency as well as throughput. Results are presented for up to 236 compute nodes (limited by the machine size available to us). Another interesting observation made from the implementation results is that performance improvement due to the assignment of additional processors to one task can improve the performance of other tasks without any increase in the number of processors assigned to them. Normally, this cannot be predicted by theoretical analysis

Effectiveness of a grant program's efforts to promote synergy within its funded initiatives: perceptions of participants of the Southern Rural Access Program

Abstract Background Foundations and public agencies commonly fund focused initiatives for individual grantees. These discrete, stand-alone initiatives can risk failure by being carried out in isolation. Fostering synergy among grantees' initiatives is one strategy proposed for promoting the success and impact of grant programs. We evaluate an explicit strategy to build synergy within the Robert Wood Johnson Foundation's Southern Rural Access Program (SRAP), which awarded grants to collaboratives within eight southeastern U.S. states to strengthen basic health care services in targeted rural counties. Methods We interviewed 39 key participants of the SRAP, including the program director within each state and the principal subcontractors heading the program's funded initiatives that supported heath professionals' recruitment, retention and training, made loans to health care providers, and built networks among providers. Interews were recorded and transcribed. Two investigators independently coded the transcripts and a third investigator distilled the main points. Results Participants generally perceived that the SRAP yielded more synergies than other grant programs in which they had participated and that these synergies added to the program's impact. The synergies most often noted were achieved through relationship building among grantees and with outside agencies, sharing information and know-how, sharing resources, combining efforts to yield greater capacity, joining voices to advocate for common goals, and spotting gaps in services offered and then filling these gaps. The SRAP's strategies that participants felt fostered synergy included targeting funding to culturally and geographically similar states, supporting complementary types of initiatives, promoting opportunities to network through semi-annual meetings and regular conference calls, and the advocacy efforts of the program's leadership. Participants noted that synergies were sometimes hindered by turf issues and politics and the conflicting perspectives and cultures of participating organizations and racial groups. Inadequate funding through the SRAP, restricting program involvement to only a few needy counties, and instances of over- and under-involvement by the program's leadership were sometimes felt to inhibit synergies and/or their sustainability. Conclusion Participants of the SRAP generally perceived that the SRAP's deliberate strategies yielded synergies that added to the program's impact

Symposium Review of "The Amish" by Donald Kraybill, Karen Johnson-Weiner, and Steven Nolt

Summary by Megan Bogden; Review by Steven Reschly; Review by Benjamin Zeller; Review by Tom Coletti; Authors' Reply by Donald Kraybill, Karen Johnson-Weiner, and Steven Nol

Acid-base changes and acetate metabolism during routine and high-efficiency hemodialysis in children

Acid-base changes and acetate metabolism during routine and high-efficiency hemodialysis in children. Changes in acid-base status and plasma acetate concentrations were studied in eight children during 11 hemodialysis sessions. During dialysis, the blood bicarbonate concentration fell (20.5 ± 0.7 to 19.6 ± 0.8 mEq/liter), the PCO2 fell (33.4 ± 0.8 to 27.5 ± 1.4 mm Hg), and the pH rose (7.42 ± 0.01 to 7.48 ± 0.02). During the hour after dialysis, the bicarbonate concentration rose to normal (23.4 ± 0.7 mEq/liter), the PCO2 rose (32.8 ± 0.8 mm Hg), and the pH remained unchanged. The half-life of plasma acetate, measured after dialysis, was 8.7 min. During five “high-efficiency” dialysis sessions (urea clearance, > 3.0 ml/min/kg), blood bicarbonate concentration fell 3.2 mEq/liter, PCO2 fell 8.7 mm Hg, and plasma acetate rose to 7.51 mmoles/liter, whereas during six “routine efficiency” dialysis sessions (urea clearance, 1.5 to 3.0 ml/min/kg), blood bicarbonate rose 1.0 mEq/liter, PCO2 fell 36 mm Hg, and plasma acetate rose to 3.52 mmoles/liter. At 1 hour after the end of dialysis, blood bicarbonate, PCO2, and plasma acetate concentrations were similar in the two groups. Clinical problems occurred more frequently in the high-efficiency group during dialysis although the difference was not significant. The data indicate that (1) dialysis with acetate buffer effectively corrects pre-dialysis metabolic acidosis, (2) although children have a high rate of acetate metabolism, during high-efficiency dialysis this rate is exceeded by the influx of acetate, and acid-base abnormalities occur. These abnormalities are transient but may cause clinical problems.Modifications acido-basiques et métabolisme de l'acétate au cours de l'hémodialyse de routine ou à efficacité élevée chez l'enfant. Les modifications de l'état acido-basique et des concentrations plasmatiques d'acétate ont été étudiées chez huit enfants au cours de 11 séances d'hémodialyse. Au cours de la dialyse les bicarbonates diminuent (20,5 ± 0,7 à 19,6 ± 0,8 mEq/ litre), la PCO2 diminue (33,4 ± 0,8 à 27,5 ± 1,4 mm Hg), et le pH augmente (7,42 ± 0,01 à 7,48 ± 0,02). Au cours de l'heure qui suit la dialyse les bicarbonates s'élèvent à une valeur normale, 23,4 ± 0,07 mEq/litre, la PCO2 s'élève à 32,8 ± 0,8 mm Hg, et le pH est inchangé. La demi vie de l'acétate plasmatique, mesurée après la dialyse, était de 8,7 min. Au cours de cinq séances de dialyse à haute efficacité (clearance de l'urée, > 3,0 ml/min/kg) les bicarbonates baissent de 3,2 mEq/litre, la PCO2 de 8,7 mm Hg, et l'acétate plasmatique s'est élevé à 7,51 mmoles/litre alors qu'au cours de six séances de dialyse d'efficacité moyenne (clearance de l'urée, 1,5 à 3,0 ml/min/kg) les bicarbonates ont augmenté de 1,0 mEq/litre, la PCO2 a diminué de 3,6 mm Hg, et l'acétate plasmatique s'est élevé à 3,52 mmoles/litre. Une heure après la fin de la dialyse les bicarbonates, la PCO2 et l'acétate plasmatique étaient semblables dans les deux groupes. Des problèmes cliniques sont survenus plus souvent au cours de la dialyse dans le groups à haute efficacité bien que la différence ne soit pas significative. Ces résultats indiquent que (1) la dialyse avec le tampon acétate corrige efficacement l'acidose métabolique pré-dialytique, (2) bien que l'enfant ait une capacité élevée de métaboliser l'acétate, cette capacité est débordée, au cours de la dialyse à haute efficacité, par l'entrée d'acétate et des anomalies acidobasiques surviennent. Ces anomalies sont transitoires et peuvent déterminer des problèmes cliniques

American political affiliation, 2003–43: a cohort component projection

The recent rise and stability in American party identification has focused interest on the long-term dynamics of party bases. Liberal commentators cite immigration and youth as forces which will produce a natural Democratic advantage in the future while conservative writers highlight the importance of high Republican fertility in securing Republican growth. These concerns foreground the neglect of demography within political science. This paper addresses this omission by conducting the first ever cohort component projection of American partisan populations to 2043 based on survey and census data. A number of scenarios are modeled, but, on current trends, we predict that American partisanship will shift much less than the nation’s ethnic composition because the parties’ age structures are similar. Still, our projections find that the Democrats gain two to three percentage points from the Republicans by 2043, mainly through immigration, though Republican fertility may redress the balance in the very long term

The Frequency of Barred Spiral Galaxies in the Near-IR

We have determined the fraction of barred galaxies in the H-band for a statistically well-defined sample of 186 spirals drawn from the Ohio State University Bright Spiral Galaxy survey. We find 56% of our sample to be strongly barred at H, while another 16% is weakly barred. Only 27% of our sample is unbarred in the near-infrared. The RC3 and the Carnegie Atlas of Galaxies both classify only about 30% of our sample as strongly barred. Thus strong bars are nearly twice as prevalent in the near-infrared as in the optical. The frequency of genuine optically hidden bars is significant, but lower than many claims in the literature: 40% of the galaxies in our sample that are classified as unbarred in the RC3 show evidence for a bar in the H-band, while for the Carnegie Atlas this fraction is 66%. Our data reveal no significant trend in bar fraction as a function of morphology in either the optical or H-band. Optical surveys of high redshift galaxies may be strongly biased against finding bars, as bars are increasingly difficult to detect at bluer rest wavelengths.Comment: LaTeX with AASTeX style file, 23 pages with 6 figures. Accepted for publication in The Astronomical Journal (Feb. 2000

Regulatory Improvement Legislation: Risk Assessment, Cost-Benefit Analysis, and Judicial Review

As the number, cost, and complexity of federal regulations have grown over the past twenty years, there has been growing interest in the use of analytic tools such as risk assessment and cost-benefit analysis to improve the regulatory process. The application of these tools to public health, safety, and environmental problems has become commonplace in the peer-reviewed scientific and medical literatures. Recent studies prepared by Resources for the Future, the American Enterprise Institute, the Brookings Institution, and the Harvard Center for Risk Analysis have demonstrated how formal analyses can and often do help government agencies achieve more protection against hazards at less cost than would otherwise occur. Although analytic tools hold great promise, their use by federal agencies is neither consistent nor rigorous. The 103rd, 104th, 105th and 106th Congresses demonstrated sustained interest in the passage of comprehensive legislation governing the employment of these tools in the federal regulatory process. While legislative proposals on this issue have attracted significant bipartisan interest, and recent amendments to particular enabling statutes have incorporated some of these analytical requirements, no comprehensive legislation has been enacted into law since passage of the Administrative Procedure Act in 1946. The inability to pass such legislation has been attributed to a variety of factors, but a common substantive concern has been uncertainty and controversy about how such legislation should address judicial review issues. For example, the judicial review portion of The Regulatory Improvement Act (S. 981), the 105th Congress\u27s major legislative initiative, was criticized simultaneously as meaningless (for allegedly offering too few opportunities for petitioners to challenge poorly reasoned agency rules) and dangerous (as supposedly enabling petitioners to paralyze even well-reasoned agency rules). Thus, a significant obstacle to regulatory improvement legislation appears to be the conflicting opinions among legal scholars and practitioners about how judicial review issues should be addressed in such legislation. The Clinton Administration and the authors of S. 981 believe they have crafted a workable compromise, one that accommodates the need to bring more rigor and transparency to an agency\u27s decisional processes without imposing excessive judicial review. Nevertheless, it is clear that their agreement on this subject, if included in future legislative deliberations, will be scrutinized and contested. Recognizing the importance of the judicial review issue to this and, indeed, any effort to improve the regulatory process, the Center for Risk Analysis at the Harvard School of Public Health convened an invitational Workshop of accomplished legal practitioners and scholars to discuss how judicial review should be handled in legislation of this kind. The full-day Workshop was conducted in Washington, D.C. on December 17, 1998. Its purpose was to discuss principles, experiences, and insights that might inform future public debate about how judicial review should be addressed in legislative proposals that entail use of risk assessment and/or cost-benefit analysis in agency decision-making (whether the proposals are comprehensive or agency-specific). In order to provide the Workshop a practical focus, participants analyzed the provisions of S. 981 (as modified at the request of the Clinton Administration). An exchange of letters between S. 981\u27s chief sponsors and the Clinton Administration defining the terms of the agreement was examined as well. This Report highlights the themes of the Workshop discussion and offers some specific commentary on how proposed legislation (including but not limited to S. 981) could be improved in future legislative deliberations

Regulatory Improvement Legislation: Risk Assessment, Cost-Benefit Analysis, and Judicial Review

As the number, cost, and complexity of federal regulations have grown over the past twenty years, there has been growing interest in the use of analytic tools such as risk assessment and cost-benefit analysis to improve the regulatory process. The application of these tools to public health, safety, and environmental problems has become commonplace in the peer-reviewed scientific and medical literatures. Recent studies prepared by Resources for the Future, the American Enterprise Institute, the Brookings Institution, and the Harvard Center for Risk Analysis have demonstrated how formal analyses can and often do help government agencies achieve more protection against hazards at less cost than would otherwise occur. Although analytic tools hold great promise, their use by federal agencies is neither consistent nor rigorous. The 103rd, 104th, 105th and 106th Congresses demonstrated sustained interest in the passage of comprehensive legislation governing the employment of these tools in the federal regulatory process. While legislative proposals on this issue have attracted significant bipartisan interest, and recent amendments to particular enabling statutes have incorporated some of these analytical requirements, no comprehensive legislation has been enacted into law since passage of the Administrative Procedure Act in 1946. The inability to pass such legislation has been attributed to a variety of factors, but a common substantive concern has been uncertainty and controversy about how such legislation should address judicial review issues. For example, the judicial review portion of The Regulatory Improvement Act (S. 981), the 105th Congress\u27s major legislative initiative, was criticized simultaneously as meaningless (for allegedly offering too few opportunities for petitioners to challenge poorly reasoned agency rules) and dangerous (as supposedly enabling petitioners to paralyze even well-reasoned agency rules). Thus, a significant obstacle to regulatory improvement legislation appears to be the conflicting opinions among legal scholars and practitioners about how judicial review issues should be addressed in such legislation. The Clinton Administration and the authors of S. 981 believe they have crafted a workable compromise, one that accommodates the need to bring more rigor and transparency to an agency\u27s decisional processes without imposing excessive judicial review. Nevertheless, it is clear that their agreement on this subject, if included in future legislative deliberations, will be scrutinized and contested. Recognizing the importance of the judicial review issue to this and, indeed, any effort to improve the regulatory process, the Center for Risk Analysis at the Harvard School of Public Health convened an invitational Workshop of accomplished legal practitioners and scholars to discuss how judicial review should be handled in legislation of this kind. The full-day Workshop was conducted in Washington, D.C. on December 17, 1998. Its purpose was to discuss principles, experiences, and insights that might inform future public debate about how judicial review should be addressed in legislative proposals that entail use of risk assessment and/or cost-benefit analysis in agency decision-making (whether the proposals are comprehensive or agency-specific). In order to provide the Workshop a practical focus, participants analyzed the provisions of S. 981 (as modified at the request of the Clinton Administration). An exchange of letters between S. 981\u27s chief sponsors and the Clinton Administration defining the terms of the agreement was examined as well. This Report highlights the themes of the Workshop discussion and offers some specific commentary on how proposed legislation (including but not limited to S. 981) could be improved in future legislative deliberations