100 research outputs found

    Geometric Gravitational Forces on Particles Moving in a Line

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    In two-dimensional space-time, point particles can experience a geometric, dimension-specific gravity force, which modifies the usual geodesic equation of motion and provides a link between the cosmological constant and the vacuum θ\theta-angle. The description of such forces fits naturally into a gauge theory of gravity based on the extended Poincar\'e group, {\it i.e.\/} ``string-inspired'' dilaton gravity.Comment: 10 pages, CTP#214

    Effects of mesophyll water potential on photosynthesis in Gramineae plants: with special reference to phylogeny of subfamilies

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    We selected several species from six Gramineae subfamilies and examined relationships between the photosynthetic rate and mesophyll water potential (ΨL). We used the oxygen electrode method originally devised by Ishii et al. and modified by Ishihara et al. Namely, we used a liquid -phase oxygen electrode and measured the O2 evolution rate

    Effects of mesophyll water potential on photosynthesis in Cyperaceae plants: with special reference to phylogeny of tribes and decarboxylation sub-types

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    We examined the photosynthetic rates under water stress conditions in 43 Japanese Cyperaceae species using the same method used for Gramineae plants. Compared with Gramineae, the difference between C4 and C3 species was more distinct in Cyperaceae. Moreover, C4 Cyperaceae species were very susceptible to water stress like Panicoideae C4 species. These species belong to the NADP-ME subtype. It appears that the sensitivity of photosynthesis to water stress would be different depending on the decarboxylation sub-types

    Extended de Sitter Theory of Two Dimensional Gravitational Forces

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    We present a simple unifying gauge theoretical formulation of gravitational theories in two dimensional spacetime. This formulation includes the effects of a novel matter-gravity coupling which leads to an extended de Sitter symmetry algebra on which the gauge theory is based. Contractions of this theory encompass previously studied cases.Comment: 19pp, no figs., CTP 2228, UCONN-93-

    Engaging with Health Markets in Low and Middle-Income Countries

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    Many low and middle-income countries have pluralistic health systems with a variety of providers of health-related goods and services in terms of their level of training, their ownership (public or private) and their relationship with the regulatory system. The development of institutional arrangements to influence their performance has lagged behind the spread of these markets. This paper presents a framework for analysing a pluralistic health system. The relationships between private providers of health services and government, or other organisations that represent the public interest, strongly influence their performance in meeting the needs of the poor. Their impact on the pattern of service delivery depends on how the relationships are managed and the degree to which they respond to the interests of the population. Many governments of low and middle-income countries are under pressure to increase access to safe, effective and affordable health services. In a context of economic growth, it should be possible to improve access by the poor to health services substantially. Innovations in information technologies and in low cost diagnostics are creating important new opportunities for achieving this. It will be important to mobilise both public and private providers of health-related goods and services. This will involve big changes in the roles and responsibilities of all health sector actors. Governments, businesses and civil society organizations will need to learn how to make pluralist health systems work better through experimentation and systematic learning about what works and why

    Established Risk Factors Account for Most of the Racial Differences in Cardiovascular Disease Mortality

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    BACKGROUND: Cardiovascular disease (CVD) mortality varies across racial and ethnic groups in the U.S., and the extent that known risk factors can explain the differences has not been extensively explored. METHODS: We examined the risk of dying from acute myocardial infarction (AMI) and other heart disease (OHD) among 139,406 African-American (AA), Native Hawaiian (NH), Japanese-American (JA), Latino and White men and women initially free from cardiovascular disease followed prospectively between 1993–1996 and 2003 in the Multiethnic Cohort Study (MEC). During this period, 946 deaths from AMI and 2,323 deaths from OHD were observed. Relative risks of AMI and OHD mortality were calculated accounting for established CVD risk factors: body mass index (BMI), hypertension, diabetes, smoking, alcohol consumption, amount of vigorous physical activity, educational level, diet and, for women, type and age at menopause and hormone replacement therapy (HRT) use. RESULTS: Established CVD risk factors explained much of the observed racial and ethnic differences in risk of AMI and OHD mortality. After adjustment, NH men and women had greater risks of OHD than Whites (69% excess, P<0.001 and 62% excess, P = 0.003, respectively), and AA women had greater risks of AMI (48% excess, P = 0.01) and OHD (35% excess, P = 0.007). JA men had lower risks of AMI (51% deficit, P<0.001) and OHD (27% deficit, P = 0.001), as did JA women (AMI, 37% deficit, P = 0.03; OHD, 40% deficit, P = 0.001). Latinos had underlying lower risk of AMI death (26% deficit in men and 35% in women, P = 0.03). CONCLUSION: Known risk factors explain the majority of racial and ethnic differences in mortality due to AMI and OHD. The unexplained excess in NH and AA and the deficits in JA suggest the presence of unmeasured determinants for cardiovascular mortality that are distributed unequally across these populations

    Serum albumin is a strong predictor of death in chronic dialysis patients

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    Serum albumin is a strong predictor of death in chronic dialysis patients. We examined the predictive value of various clinical variables in assessing survival in chronic hemodialysis patients (N = 1,243, 524 females, 719 males) who were under treatment with hemodialysis as of January 1991 in Okinawa, Japan and who were followed up until April 1992. Basal clinical data such as sex, starting date of dialysis, primary renal disease, blood pressure, blood chemistry values, and dialysis prescription data obtained just prior to dialysis were registered at the start of the study. As of the end of April 1992, 104 had died, 16 were transplant recipients, and five had been transferred. Those who died had significantly lower levels of total protein, serum albumin, total cholesterol, triglyceride, BUN, serum creatinine, body weight, body height, diastolic blood pressure, and duration of hemodialysis than those who survived. Older patients and those with diabetes mellitus had a poorer prognosis. A forward stepwise logistic procedure by SAS was used to determine the predictive value of the above clinical variables. With the addition of laboratory variables, the predictive value of diabetes was lost, as the diabetic patients had low serum levels of albumin and creatinine. The standardized coefficient was -0.380 (P = 0.0001) at age of entry, 0.316 (P = 0.0001) for serum albumin, 0.280 (P = 0.0001) for serum creatinine, 0.138 (P = 0.043) for body mass index (BMI), and -0.139 (P = 0.016) for male sex. The prescribed dialysis dose (M2 hr per week) was significantly correlated with serum creatinine (r = 0.48, P = 0.0001), serum albumin (r = 0.135, P = 0.0001) and BMI (r = 0.275, P = 0.0001). Serum albumin was found to be a strong predictor of death in chronic hemodialysis patients. Causes of low serum albumin should be carefully evaluated if underlying illness is not evident
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