4,824 research outputs found

    Untangling the Most Probable Role for Vitamin D\u3csub\u3e3\u3c/sub\u3e in Autism

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    Recent studies indicate an important role for vitamin D3 in autism spectrum disorder (ASD), although its mechanism is not completely understood. The most puzzling aspect of ASD is that identical twins, who share identical DNA, do not have 100% concordance rates (∼88% for identical and ∼31% for fraternal twins). These findings provide major clues into the etiology: ASD must involve an environmental factor present in the prenatal milieu that both identical twins are not always exposed to because they do not always share it (i.e., placentas). Combined with the exponential increasing rates of ASD around the world, these observations suggest a contagious disease is probably transferred to the fetus via the placenta becoming infected by a cervical virus. Vitamin D3 boosts immune responses clearing viral infections and increases serotonin and estrogen brain levels. Here we review the different roles and untangle the most probable one vitamin D3 plays in ASD

    Spectral irradiance curve calculations for any type of solar eclipse

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    A simple procedure is described for calculating the eclipse function (EF), alpha, and hence the spectral irradiance curve (SIC), (1-alpha), for any type of solar eclipse: namely, the occultation (partial/total) eclipse and the transit (partial/annular) eclipse. The SIC (or the EF) gives the variation of the amount (or the loss) of solar radiation of a given wavelength reaching a distant observer for various positions of the moon across the sun. The scheme is based on the theory of light curves of eclipsing binaries, the results of which are tabulated in Merrill's Tables, and is valid for all wavelengths for which the solar limb-darkening obeys the cosine law: J = sub c (1 - X + X cost gamma). As an example of computing the SIC for an occultation eclipse which may be total, the calculations for the March 7, 1970, eclipse are described in detail

    Diffusion-based method for producing density equalizing maps

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    Map makers have long searched for a way to construct cartograms -- maps in which the sizes of geographic regions such as countries or provinces appear in proportion to their population or some other analogous property. Such maps are invaluable for the representation of census results, election returns, disease incidence, and many other kinds of human data. Unfortunately, in order to scale regions and still have them fit together, one is normally forced to distort the regions' shapes, potentially resulting in maps that are difficult to read. Many methods for making cartograms have been proposed, some of them extremely complex, but all suffer either from this lack of readability or from other pathologies, like overlapping regions or strong dependence on the choice of coordinate axes. Here we present a new technique based on ideas borrowed from elementary physics that suffers none of these drawbacks. Our method is conceptually simple and produces useful, elegant, and easily readable maps. We illustrate the method with applications to the results of the 2000 US presidential election, lung cancer cases in the State of New York, and the geographical distribution of stories appearing in the news.Comment: 12 pages, 3 figure

    Her Life Depends on it III: Sport, Physical Activity and the Health and Well-being of American Girls and Women

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    Her Life Depends On It III is the Women's Sports Foundation's comprehensive report that reviews existing and emerging research on the links between participation in sport and physical activity and the health and wellbeing of American girls and women. As with the previous editions in 2004 and 2009, this study also confirms that physical activity and sport provides the critical foundation, in no small part, that allows girls and women to lead healthy, strong, and fulfilled lives. Ten years since its first publication, the updated Her Life Depends On It provides an even more comprehensive review of the ever-expanding body of research that demonstrates how important it is for girls and women to participate in sport and physical activity. The report's contents reflect the review of 1,500 studies, nearly 400 covered since the previous edition

    Her Life Depends On It: Sport, Physical Activity and the Health and Well-Being of American Girls

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    This report is a comprehensive compendium of research that points to physical activity and sport as fundamental solutions for many of the serious health and social problems faced by American girls. An appreciable mass of evidence-based knowledge about girls' involvement with sport and physical activity has been generated during the last decade. The amount and quality of this research are uneven and varied. For example, a good deal of research examines the associations between physical activity and risk for coronary heart disease, but studies that focus on risk for Alzheimer's disease are just beginning to issue. Researchers have verified links between high school athletic participation and teen pregnancy prevention, although more longitudinal research is needed to thoroughly confirm the connections. Overall, however, this report shows that the current state of knowledge on the relationship of physical activity to the health and social needs of American girls warrants the serious attention of public health officials, educators and sport leaders

    How linear features alter predator movement and the functional\ud response

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    In areas of oil and gas exploration, seismic lines have been reported to alter the movement patterns of wolves (Canis lupus). We developed a mechanistic first passage time model, based on an anisotropic elliptic partial differential equation, and used this to explore how wolf movement responses to seismic lines influence the encounter rate of the wolves with their prey. The model was parametrized using 5 min GPS location data. These data showed that wolves travelled faster on seismic lines and had a higher probability of staying on a seismic line once they were on it. We simulated wolf movement on a range of seismic line densities and drew implications for the rate of predator–prey interactions as described by the functional response. The functional response exhibited a more than linear increase with respect to prey density (type III) as well as interactions with seismic line density. Encounter rates were significantly higher in landscapes with high seismic line density and were most pronounced at low prey densities. This suggests that prey at low population densities are at higher risk in environments with a high seismic line density unless they learn to avoid them

    Many-Body Electrostatic Forces Between Colloidal Particles at Vanishing Ionic Strength

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    Electrostatic forces between small groups of colloidal particles are measured using blinking optical tweezers. When the electrostatic screening length is significantly larger than the particle radius, forces are found to be non-pairwise additive. Both pair and multi-particle forces are well described by the linearized Poisson-Boltzmann equation with constant potential boundary conditions. These findings may play an important role in understanding the structure and stability of a wide variety of systems, from micron-sized particles in oil to aqueous nanocolloids.Comment: 5 pages 2 figure

    Age Study of Minnesota Red Fox Using Cementum Annulae Counts and Tooth X-Rays

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    A prerequisite to the proper management of an animal species is understanding of its population dynamics. Attempting this, the age structure of 297 red fox trapped or shot in southern Minnesota was investigated, using the techniques of tooth sectioning and x-ray. Results from two seasons (1977 and 1978) were similar, with 76.8 percent of the harvested population being juveniles (78.4 percent, 1977 and 74.6 percent, 1978), whereas only 0 .6 percent of the total were in the 4½ year old class. The percentage of juveniles corresponds closely to the numbers predicted by a Department of Natural Resources model developed by Al Berner of the Farmland Research Unit. If a population reacts in a density-dependent manner, an increase in the breeding density should reduce the reproductive rate, and vice-versa. Data of this paper tend to support the premise that the reproductive rate in Minnesota red fox is affected in a density-dependent manner

    Thin film dielectric microstrip kinetic inductance detectors

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    Microwave Kinetic Inductance Detectors, or MKIDs, are a type of low temperature detector that exhibit intrinsic frequency domain multiplexing at microwave frequencies. We present the first theory and measurements on a MKID based on a microstrip transmission line resonator. A complete characterization of the dielectric loss and noise properties of these resonators is performed, and agrees well with the derived theory. A competitive noise equivalent power of 5×1017\times10^{-17} W Hz1/2^{-1/2} at 1 Hz has been demonstrated. The resonators exhibit the highest quality factors known in a microstrip resonator with a deposited thin film dielectric.Comment: 10 pages, 4 figures, APL accepte
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