84 research outputs found
Effects of Chameleon Scalar Field on Rotation Curves of the Galaxies
We investigate the effects of chameleon scalar field to the effective density
and pressure of a dark matter halo. The pressure is generated from the
chameleonic fifth force on the matter. We demonstrate that the thick-shell
non-singular boundary condition which forbids singular point leads to extremely
stringent constraint on the matter-chameleon coupling when applied to galaxy.
We argue that chameleon profile with central singularity is more likely to
develop in general physical situation. The chameleonic fifth force from the
chameleon profile with central singularity experienced by the dark matter could
significantly modify the rotation curve of galaxies. The chameleonic fifth
force could generate steeper cusp to the rotation curves in any dark matter
profiles starting from the Navarro-Frenk-White (NFW) to the pseudo-isothermal
(ISO) profile. Upper limits on the coupling constant between the chameleon and
the dark matter are estimated from observational data of the late-type
Low-Surface-Brightness galaxies (LSB). It is in the order of .Comment: 26 pages, 13 figures, 1 table, extended version to include more
viable self-potential and analytic solutions. To be published in IJMP
A rapid situation analysis of the access to care project in Northern Thailand
A rapid situation analysis (RSA) study, supported by the Horizons program, was undertaken to understand the strengths and weaknesses of the Thai government’s Access to Care (ATC) project in northern Thailand. The ultimate aim of the study was to make recommendations for action that will improve the quality of the antiretroviral (ARV) therapy that clients receive and to enhance their adherence to HAART. The RSA has shown high levels of support for the ATC project from health providers, HAART clients, their relatives, and even those who had dropped out of the program. However, the RSA has also shown that there has been a high dropout rate and that a substantial number of the clients receiving HAART have had difficulties maintaining adherence. The report offers numerous recommendations to improve the system in order to reduce dropouts and increase adherence among new clients
Children in reviews: Methodological issues in child-relevant evidence syntheses
BACKGROUND: The delivery of optimal medical care to children is dependent on the availability of child relevant research. Our objectives were to: i) systematically review and describe how children are handled in reviews of drug interventions published in the Cochrane Database of Systematic Reviews (CDSR); and ii) determine when effect sizes for the same drug interventions differ between children and adults. METHODS: We systematically identified all of the reviews relevant to child health in the CDSR 2002, Issue 4. Reviews were included if they investigated the efficacy or effectiveness of a drug intervention for a condition that occurs in both children and adults. Information was extracted on review characteristics including study methods, results, and conclusions. RESULTS: From 1496 systematic reviews, 408 (27%) were identified as relevant to both adult and child health; 52% (213) of these included data from children. No significant differences were found in effect sizes between adults and children for any of the drug interventions or conditions investigated. However, all of the comparisons lacked the power to detect a clinically significant difference and wide confidence intervals suggest important differences cannot be excluded. A large amount of data was unavailable due to inadequate reporting at the trial and systematic review level. CONCLUSION: Overall, the findings of this study indicate there is a paucity of child-relevant and specific evidence generated from evidence syntheses of drug interventions. The results indicate a need for a higher standard of reporting for participant populations in studies of drug interventions
Micronutrient status in lactating mothers before and after introduction of fortified flour: cross-sectional surveys in Maela refugee camp
Background Deficiency of micronutrients is common in refugee populations. Objectives Identify deficiencies and whether provided supplements and wheat flour fortified with 10 micronutrients impacts upon status among breast-feeding women from Maela refugee camp. Methods Two sequential cross-sectional studies were conducted in different groups of lactating mothers at 12 weeks postpartum. The first survey was before and the second 4-5 months after micronutrient fortified flour (MFF) had been provided to the camp (in addition to the regular food basket). Iron status and micronutrients were measured in serum, whole blood, and in breast milk samples. Results Iron and zinc deficiency and anemia were highly prevalent while low serum retinol and thiamine deficiency were rarely detected. Iron and zinc deficiency were associated with anemia, and their proportions were significantly lower after the introduction of MFF (21 vs. 35% with soluble transferrin receptor (sTfR)>8.5 mg/L, P = 0.042, and 50 vs. 73% with serum zinc<0.66 mg/L, P = 0.001). Serum sTfR, whole-blood thiamine diphosphate (TDP) and serum β-carotene were significant predictors (P<0.001) of milk iron, thiamine and β-carotene, respectively. Lower prevalence of iron deficiency in the MFF group was associated with significantly higher iron and thiamine in breast milk. Conclusions High whole-blood TDP and breast milk thiamine reflected good compliance to provided thiamine; high prevalence of iron deficiency suggested insufficient dietary iron and low acceptance to ferrous sulfate supplements. MFF as an additional food ration in Maela refugee camp seemed to have an effect in reducing both iron and zinc deficiency postpartum. © Springer-Verlag 2012
Dengue Deaths in Puerto Rico: Lessons Learned from the 2007 Epidemic
Dengue is a major public health problem in the tropics and subtropics; an estimated 50 million cases occur annually and 40 percent of the world's population lives in areas with dengue virus (DENV) transmission. Dengue has a wide range of clinical presentations from an undifferentiated acute febrile illness, classic dengue fever, to severe dengue (i.e., dengue hemorrhagic fever or dengue shock syndrome). About 5% of patients develop severe dengue, which is more common with second or subsequent infections. No vaccines are available to prevent dengue, and there are no specific antiviral treatments for patients with dengue. However, early recognition of shock and intensive supportive therapy can reduce risk of death from ∼10% to less than 1% among severe dengue cases. Reviewing dengue deaths is one means to identify issues in clinical management. These findings can be used to develop healthcare provider education to minimize dengue morbidity and mortality
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