The Oblate Schwarzschild Approximation for Light Curves of Rapidly Rotating Neutron Stars

We present a simple method for including the oblateness of a rapidly rotating neutron star when fitting X-ray light curves. In previous work we showed that the oblateness induced by rotation at frequencies above 300 Hz produces a geometric effect which needs to be accounted for when modelling light curves to extract constraints on the neutron star's mass and radius. In our model X-rays are emitted from the surface of an oblate neutron star and propagate to the observer along geodesics of the Schwarzschild metric for a spherical neutron star. Doppler effects due to rotation are added in the same manner as in the case of a spherical neutron star. We show that this model captures the most important effects due to the neutron star's rotation. We also explain how the geometric oblateness effect can rival the Doppler effect for some emission geometries.Comment: 8 pages, 4 figures. v2: minor changes. Accepted by the Astrophysical Journa

Proposal for the Creation of a Subdiscipline: Education Informatics

“Education Informatics” is the name for an emerging new sub-discipline of education. We define “Education Informatics” as the application of technology to discovering and communicating education information. This article will provide an historical and theoretical foundation for the emergence of this new sub-discipline. Existing definitions of informatics, the literature on education informatics, and the evolution of academic disciplines will be examined. The authors will explore commonalities between the two disciplines from which education informatics is derived: information science and education. They will justify the foundation of the sub-discipline, grounding it within the existing discipline of education. The article will conclude with a discussion of how this new sub-discipline might impact research and practice; a plan for incorporating the new sub-discipline in the educational system; and a proposed research agenda

Slow gait speed and cardiac rehabilitation participation in older adults after acute myocardial infarction

Background Lack of participation in cardiac rehabilitation ( CR ) and slow gait speed have both been associated with poor long‐term outcomes in older adults after acute myocardial infarction ( AMI ). Whether the effect of CR participation on outcomes after AMI differs by gait speed is unknown. Methods and Results We examined the association between gait speed and CR participation at 1 month after discharge after AMI , and death and disability at 1 year, in 329 patients aged ≥65 years enrolled in the TRIUMPH (Translational Research Investigating Underlying Disparities in Recovery From Acute Myocardial Infarction: Patients' Health Status) registry. Among these patients, 177 (53.7%) had slow gait speed (&lt;0.8 m/s) and 109 (33.1%) participated in CR . Patients with slow gait speed were less likely to participate in CR compared with patients with normal gait speed (27.1% versus 40.1%; P =0.012). In unadjusted analysis, CR participants with normal gait speed had the lowest rate of death or disability at 1 year (9.3%), compared with those with slow gait speed and no CR participation (43.2%). After adjustment for cardiovascular risk factors and cognitive impairment, both slow gait speed (odds ratio, 2.30; 95% confidence interval, 1.30–4.06) and non‐ CR participation (odds ratio, 2.34; 95 confidence interval, 1.22–4.48) were independently associated with death or disability at 1 year. The effect of CR on the primary outcome did not differ by gait speed ( P =0.70). Conclusions CR participation is associated with reduced risk for death or disability after AMI . The beneficial effect of CR participation does not differ by gait speed, suggesting that slow gait speed alone should not preclude referral to CR for older adults after AMI . </jats:sec

Reduction of Uranium by Bacterial Products

The Old Rifle Mill Processing site at Rifle, CO, contains uranium contaminated groundwater. The presence of uranium is one of the major problems at Department of Energy legacy sites. There is an initiative for attenuation of uranium by the Department of Energy. Uranium undergoes oxidation/reduction reactions with the substances at the site. Uranium’s oxidation state determines its solubility and mobility in the aquifer. The oxidation reduction pathways at this site have mineralogical, microbial and geochemical components. Understanding the oxidation/reduction pathways of these components will allow for better predictions of the changes and movement of uranium. Sulfide [S2- ] and Ferrous [Fe2] ions are products of microbial activity. These ions can reduce uranium [U(VI)], but bicarbonate ions [HCO3-] in the aquifers slows down the reaction. However, we believe that organic matter in the environment enhances U(VI) reduction by Fe2+and S2- in the absence of microbes. To address this, U(VI) was mixed with Fe2+ or S2- in autoclaved biomass from Rifle and artificial groundwater for seven to eleven days. Aqueous samples from the vials will be analyzed for Uranium presence using ICP-MS [Inductively Coupled Plasma- Mass Spectrometry]. The biomass from each of the samples will be analyzed using XAS [X-Ray Absorption Spectroscopy] to determine the ionization state of Uranium. Based on the data, we can conclude that there is a significant decrease of the concentration of uranium from the reaction when the biomass was not sterilized. There were no differences within in the vials that had Fe2+ or S2-. The XAS data shows a mixture of U(IV) and U(VI) in the biomasss and more U(IV) in the biomass that was not sterilized. This suggests that the bacterial products alone is not completely responsible for the reduction of uranium

WIC Improves Child Health and School Readiness

New research by Children's HealthWatch demonstrates that young children who participate in the Special Supplemental Nutrition program for Women, Infants, and Children (WIC) are more likely to be in excellent or good health and have a reduced risk of developmental delay. Investing in WIC supports the nutritional and health needs of young children during a critical window of brain and body growth.Progam improvements that decrease access barriers, provide the full amount of fruits and vegetables recommended by the Institute of Medicine, and accommodate working parents' schedules will help young children reach their full potential

Energy Insecurity is a Major Threat to Child Health

With the recession and this winter's harsh weather, many families are facing a choice between eating and heating. Research by Children's HealthWatch shows that young children whose families struggle to pay their utility bills ('energy insecure' families) are more likely to suffer a host of problems including food insecurity, poor health, hospitalizations and developmental delays.The Low Income Home Energy Assistance Program (LIHEAP), which provides low-income households with assistance in paying their utility bills, is effective at shielding young children from the harmful effects of energy insecurity.According to research by Children's HealthWatch, young children whose families received LIHEAP were less likely to be at risk for growth problems and had healthier weights for their age.By appropriating the maximum authorized funding for LIHEAP and ensuring that climate change legislation buffers vulnerable families and children from the harmful effects of higher energy prices, Congress will be taking important steps to protect children's health

Too Many Hurdles: Barriers to Receiving SNAP Put Childrens Health at Risk

Summary of Findings

Child Care Feeding Programs Support Young Children's Healthy Development

New research by Children's HealthWatch shows that toddlers from low-income families who receive meals from their child care provider - those likely to be receiving CACFP - are in better health, have decreased risk for hospitalization, and are at healthier heights and weights for their age than those whose have to bring meals from home. As the nation's only nutrition program for young children in child care, CACFP is a critical component of a comprehensive approach to child nutrition.Changes to CACFP that expand access, reduce barriers and ensure that child care providers have the resources they need to provide healthy meals are beneficial for young children's health, growth and development

LIHEAP Stabilizes Family Housing and Protects Children's Health

The heating and cooling season presents special challenges for our nation's low-income families. With limited resources, many are challenged to manage the seasonal spike in utility expenses, facing decisions about whether to pay the rent, keep the lights and heat on, or buy enough groceries to get through the end of the month. We know that each of these decisions will have significant implications for the health of their youngest children. Unfortunately, these tough choices are all too common this winter as the nation experiences increases in energy prices, unusually cold weather, and continued high unemployment