The primordial and evolutionary abundance variations in globular-cluster stars: a problem with two unknowns

We demonstrate that among the potential sources of the primordial abundance variations of the proton-capture elements in globular-cluster stars proposed so far, such as the hot-bottom burning in massive AGB stars and H burning in the convective cores of supermassive and fast-rotating massive MS stars, only the supermassive MS stars with M > 10,000 Msun can explain all the observed abundance correlations without any fine-tuning of model parameters. We use our assumed chemical composition for the pristine gas in M13 (NGC6205) and its mixtures with 50% and 90% of the material partially processed in H burning in the 60,000 Msun MS model star as the initial compositions for the normal, intermediate and extreme populations of low-mass stars in this globular cluster, as suggested by its O-Na anti-correlation. We evolve these stars from the zero-age MS to the RGB tip with the thermohaline and parametric prescriptions for the RGB extra mixing. We find that the 3He-driven thermohaline convection cannot explain the evolutionary decline of [C/Fe] in M13 RGB stars, which, on the other hand, is well reproduced with the universal values for the mixing depth and rate calibrated using the observed decrease of [C/Fe] with MV in the globular cluster NGC5466 that does not have the primordial abundance variations.Comment: 11 pages, 1 table, 8 figures, accepted for publication in MNRA

Monitoring the Impact of Influenza by Age: Emergency Department Fever and Respiratory Complaint Surveillance in New York City

Don Olson and colleagues report that influenza-related morbidity in NYC from 2001 to 2006 was highly age- and strain-specific and conclude that surveillance using electronic data can provide timely and representative information about the epidemiology of circulating influenza viruses

Community concepts of malaria-related illness with and without convulsions in southern Ghana

BACKGROUND: Malaria, both with or without convulsions, is a serious hardship for people living in endemic areas, especially in sub-Saharan Africa. Community references to malaria, however, may encompass other conditions, which was collectively designated malaria-related illness (MRI). Inasmuch as the presence or absence of convulsions reportedly affects timely help-seeking for malaria, a local comparison of these conditions is needed to inform malaria control. METHODS: Vignette-based EMIC interviews (insider-perspective interviews) for MRI with convulsions (convulsion positive, MRI-CP) and without convulsions (convulsion negative, MRI-CN) were developed to study relevant features of MRI-related experience, meaning and behaviour in two rural communities in Ghana. These semi-structured interviews elicited both qualitative narrative and categorical codes for quantitative analysis. Interviews with 201 respondents were conducted. RESULTS: The conditions depicted in the vignettes were well recognized by respondents and named with various local terms. Both presentations were considered serious, but MRI-CP was more frequently regarded potentially fatal than MRI-CN. More than 90.0% of respondents in both groups acknowledged the need to seek outside help. However, significantly more respondents advised appropriate help-seeking within 24 (p = 0.01) and 48 (p = 0.01) hours for MRI-CP. Over 50.0% of respondents responding to questions about MRI-CP identified MRI-CN as a cause of convulsions. CONCLUSION: Local comparison of MRI-CP and MRI-CN based on vignettes found a similar profile of reported categories of perceived causes, patterns of distress, help-seeking and preventive measures for both presentations. This differs from previous findings in sub-Saharan Africa, which assert communities regard the two conditions to be unrelated. The perceived relationships should be acknowledged in formulating strategies to control malaria through timely help-seeking and treatment to reduce childhood mortality

An Examination of Recent Transformations to the BV(RI)_C Photometric System from the Perspective of Stellar Models for Old Stars

Isochrones for ages > 4 Gyr and metallicities in the range -2.5 < [Fe/H] < +0.3 that take the diffusion of helium and recent advances in stellar physics into account are compared with observations in the Johnson-Cousins BV(RI)_C photometric system for several open and globular star clusters. The adopted color-Teff relations include those which we have derived from the latest MARCS model atmospheres and empirical transformations for dwarf and subgiant stars given by Casagrande et al (2010, A&A, 512, 54; CRMBA). Those reported by VandenBerg & Clem (2003, AJ, 126, 778) have also been considered, mainly to resolve some outstanding questions concerning them. Remarkably, when the subdwarfs in the CRMBA data set that have sigma_pi/pi < 0.15 are superimposed on a set of 12 Gyr isochrones spanning a wide range in [Fe/H], the inferred metallicities and effective temperatures agree, in the mean, with those given by CRMBA to within +/- 0.05 dex and +/- 10 K, respectively. Thus the hot Teff scale derived by CRMBA is nearly identical with that predicted by stellar models and consequently, there is excellent consistency between theory and observations on the H-R diagram and the different color-magnitude diagrams considered in this investigation. To obtain similar consistency, the colors obtained from the MARCS and VandenBerg & Clem B-V vs. Teff relations for metal-poor dwarf stars should be adjusted to the red by 0.02-0.03 mag. In general, isochrones that employ the CRMBA transformations provide reasonably good fits to our BV(RI)_C photometry for main-sequence stars in the globular clusters 47 Tuc, M3, M5, M92 and NGC 1851 - but not the cluster giants (when adopting the synthetic MARCS colors). We speculate that differences between the actual heavy-element mixtures and those assumed in the theoretical models may be the primary cause of this difficulty.Comment: To appear in 2010, AJ, 140, 102

Association of neighborhood-level factors with hospitalization for community-associated methicillin-resistant Staphylococcus aureus, New York City, 2006: a multilevel observational study

Background: Hospitalizations with community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infection have increased in New York City, with substantial geographic variation across neighborhoods. While individual-level risk factors, such as age, sex, HIV infection, and diabetes have been described, the role of neighborhood-level factors (e.g., neighborhood HIV prevalence or income) has not been examined. Methods: To explore plausible neighborhood-level factors associated with CA-MRSA-related hospitalizations, a retrospective analysis was conducted using New York City hospital discharges from 2006 and New York City-specific survey and health department surveillance data. CA-MRSA-related hospitalizations were identified using diagnosis codes and admission information. Associations were determined by using sex-specific multilevel logistic regression. Results: The CA-MRSA hospitalization rate varied by more than six-fold across New York City neighborhoods. Females hospitalized with CA-MRSA had more than twice the odds of residing in neighborhoods in the highest quintile of HIV prevalence (adjusted odds ratio [AOR]Q5 vs. Q1 2.3, 95% CI: 1.2, 2.7). Both males and females hospitalized with CA-MRSA had nearly twice the odds of residing in neighborhoods with moderately high proportion of men who have sex with men (MSM) residing in the neighborhood (males: AORQ4 vs. Q1 1.7, 95% CI: 1.1, 2.7; females: AORQ4 vs. Q1 2.0, 95% CI: 1.1, 3.6); but this association did not hold for neighborhoods in the highest quintile (males: AORQ5 vs. Q1 1.2, 95% CI: 0.76, 1.8; females: AORQ5 vs. Q1 1.5, 95% CI: 0.82, 2.7). Conclusions: Neighborhood-level characteristics were associated with CA-MRSA hospitalization odds, independent of individual-level risk factors, and may contribute to the population-level burden of CA-MRSA infection

Amorphous Computing

Amorphous computing is the development of organizational principles and programming languages for obtaining coherent behaviors from the cooperation of myriads of unreliable parts that are interconnected in unknown, irregular, and time-varying ways. The impetus for amorphous computing comes from developments in microfabrication and fundamental biology, each of which is the basis of a kernel technology that makes it possible to build or grow huge numbers of almost-identical information-processing units at almost no cost. This paper sets out a research agenda for realizing the potential of amorphous computing and surveys some initial progress, both in programming and in fabrication. We describe some approaches to programming amorphous systems, which are inspired by metaphors from biology and physics. We also present the basic ideas of cellular computing, an approach to constructing digital-logic circuits within living cells by representing logic levels by concentrations DNA-binding proteins

Transfusion-Associated Babesiosis after Heart Transplant

We describe a 54-year-old spleen-intact man with transfusion-associated Babesia microti infection after a heart transplant. Adult respiratory distress syndrome developed in the patient, and he required mechanical ventilation. Our experiences with this patient suggest that babesiosis should be considered in the differential diagnosis of transplant patients who have fever and hemolytic anemia

Evaluation of school absenteeism data for early outbreak detection, New York City

BACKGROUND: School absenteeism data may have utility as an early indicator of disease outbreaks, however their value should be critically examined. This paper describes an evaluation of the utility of school absenteeism data for early outbreak detection in New York City (NYC). METHODS: To assess citywide temporal trends in absenteeism, we downloaded three years (2001–02, 2002–03, 2003–04) of daily school attendance data from the NYC Department of Education (DOE) website. We applied the CuSum method to identify aberrations in the adjusted daily percent absent. A spatial scan statistic was used to assess geographic clustering in absenteeism for the 2001–02 academic year. RESULTS: Moderate increases in absenteeism were observed among children during peak influenza season. Spatial analysis detected 790 significant clusters of absenteeism among elementary school children (p < 0.01), two of which occurred during a previously reported outbreak. CONCLUSION: Monitoring school absenteeism may be moderately useful for detecting large citywide epidemics, however, school-level data were noisy and we were unable to demonstrate any practical value in using cluster analysis to detect localized outbreaks. Based on these results, we will not implement prospective monitoring of school absenteeism data, but are evaluating the utility of more specific school-based data for outbreak detection

Socio-cultural determinants of treatment delay for childhood malaria in southern Ghana

We studied socio-cultural determinants of timely appropriate treatment seeking for children under 5 years suspected of having a perceived malaria-related illness. Caretakers of children with suspected malaria were interviewed about illness-related experiences, meanings and behaviour in two endemic villages in southern Ghana. Only 11% of children suspected of having a perceived malaria-related illness received timely appropriate treatment consistent with the Abuja target of treating malaria within 24 h of illness onset; 33% of children received appropriate treatment within 48 h. Reported perceived causes of phlegm predicted timely, appropriate treatment within 24 h of illness onset (P = 0.04) in a multivariate logistic regression model; playing on the ground (P < 0.01) predicted such treatment within 48 h. Two categories of distress, paleness or shortage of blood (P = 0.05) and sweating profusely (P = 0.03), also predicted timely, appropriate treatment within 24 h in a multivariate logistic regression model. Knowing that mosquitoes transmit malaria was not associated with timely, appropriate help seeking for the children, even though such knowledge may promote personal protective measures, especially use of bednets. Patterns of distress and PC were related to timely, appropriate help seeking, but not as expected. Effects on health seeking of illness-related experience and meaning are complex, and explaining their role may strengthen interventions for childhood malaria