387 research outputs found

    Sacral Spina Bifida Occulta: A Frequency Analysis of Secular Change

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    Substantial relaxation of natural selection beginning around 1900 changed the mutation/selection balance of modern genetic material, producing an increase in variable anatomical structures. While multiple structures have been affected, the temporal increase in variations of the sacrum, specifically, ‘Sacral Spina Bifida Occulta,’ have been reliably demonstrated on a localised scale. Calculation of largescale frequency has been hindered by the localised nature of these publications, the morphological variability of this variation, and potential pathological associations, which have produced divergent classifications, and conflicting reported rates of occurrence. A systematic review of the reported literature was conducted to provide an objective analysis of Sacral Spina Bifida Occulta frequency from 2500 BCE to the present. This review was designed to compensate for observed inconsistencies in reporting and to ascertain, for the first time, the temporal trajectory of this secular trend. A systematic review of Sacral Spina Bifida Occulta literature was conducted through the strict use of clinical meta-analysis criteria. Publications were retrieved from four databases: PubMed, Embase, the Adelaide University Library database, and Google Scholar. Data were separated into three historical groups, (1 = 1980), and frequency outcomes compared, to determine temporal rates of occurrence.1980CE). These increases were significant at p/p

    Marital status distribution of the U.K. military: Does it differ from the general population?

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    UK media suggest UK military personnel have high divorce rates; to date, these claims are not substantiated. Marital status distribution of the general population and military were compared using data from the Office for National Statistics marital projections (2008) and a military cohort study (2007 – 2009), respectively. Data from the military cohort study was collected via questionnaire with a response rate of 56% for the overall cohort questionnaire and 99.5% for the martial status question. Overall, military personnel (59.4%) were more likely to be married than the general population (49.3%) and less likely to be divorced (3.7%) than the general population (10.0%). Military females and military personnel married under 30 years of age are more likely to report divorce. Military welfare services might target these groups with programs assisting marital relationships

    Robot life: simulation and participation in the study of evolution and social behavior.

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    This paper explores the case of using robots to simulate evolution, in particular the case of Hamilton's Law. The uses of robots raises several questions that this paper seeks to address. The first concerns the role of the robots in biological research: do they simulate something (life, evolution, sociality) or do they participate in something? The second question concerns the physicality of the robots: what difference does embodiment make to the role of the robot in these experiments. Thirdly, how do life, embodiment and social behavior relate in contemporary biology and why is it possible for robots to illuminate this relation? These questions are provoked by a strange similarity that has not been noted before: between the problem of simulation in philosophy of science, and Deleuze's reading of Plato on the relationship of ideas, copies and simulacra

    Thermal preconditioning and heat-shock protein 72 preserve synaptic transmission during thermal stress

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    As with other tissues, exposing the mammalian CNS to nonlethal heat stress (i.e., thermal preconditioning) increases levels of heat-shock proteins (Hsps) such as Hsp70 and enhances the viability of neurons under subsequent stress. Using a medullary slice preparation from a neonatal mouse, including the site of the neural network that generates respiratory rhythm (the pre-Bö tzinger complex), we show that thermal preconditioning has an additional fundamental effect, protection of synaptic function. Relative to 30°C baseline, initial thermal stress (40°C) greatly increased the frequency of synaptic currents recorded without pharmacological manipulation by ϳ17-fold ( p Ͻ 0.01) and of miniature postsynaptic currents (mPSCs) elicited by GABA (20-fold) glutamate (10-fold), and glycine (36-fold). Thermal preconditioning (15 min at 40°C) eliminated the increase in frequency of overall synaptic transmission during acute thermal stress and greatly attenuated the frequency increases of GABAergic, glutamatergic, and glycinergic mPSCs (for each, p Ͻ 0.05). Moreover, without thermal preconditioning, incubation of slices in solution containing inducible Hsp70 (Hsp72) mimicked the effect of thermal preconditioning on the stressinduced release of neurotransmitter. That preconditioning and exogenous Hsp72 can affect and preserve normal physiological function has important therapeutic implications. Key words: hyperthermia; heat shock; synaptic transmission; miniature postsynaptic current; GABA; glutamate; glycine The discovery that preconditioning with mild stress protects neural tissue from severe stresses such as hyperthermia or hypoxia has yielded new ideas on how to mitigate brain damage by ischemia and strok

    Superconductivity above 30 K in alkali-metal-doped hydrocarbon

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    The recent discovery of superconductivity with a transition temperature (Tc) at 18 K in Kxpicene has extended the possibility of high-Tc superconductors in organic materials. Previous experience based on similar hydrocarbons, like alkali-metal doped phenanthrene, suggested that even higher transition temperatures might be achieved in alkali-metals or alkali-earth-metals doped such polycyclic-aromatic-hydrocarbons (PAHs), a large family of molecules composed of fused benzene rings. Here we report the discovery of high-Tc superconductivity at 33 K in K-doped 1,2:8,9-dibenzopentacene (C30H18). To our best knowledge, it is higher than any Tc reported previously for an organic superconductor under ambient pressure. This finding provides an indication that superconductivity at much higher temperature may be possible in such PAHs system and is worthy of further exploration

    The relationship between foot arch measurements and walking parameters in children

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    BACKGROUND: Walking mechanics are influenced by body morphology. Foot arch height is one aspect of body morphology central to walking. However, generalizations about the relationship between arch height and walking are limited due to previous methodologies used for measuring the arch and the populations that have been studied. To gain the knowledge needed to support healthy gait in children and adults, we need to understand this relationship in unimpaired, typically developing children and adults using dynamic measures. The purpose of the current study was to examine the relationship between arch height and gait in a sample of healthy children and adults using dynamic measures. METHODS: Data were collected from 638 participants (n = 254 children and n = 384 adults) at the Museum of Science, Boston (MOS) and from 18 4- to 8-year-olds at the Motor Development and Motor Control Laboratories. Digital footprints were used to calculate two arch indices: the Chippaux-Smirak (CSI) and the Keimig Indices (KI). The height of the navicular bone was measured. Gait parameters were captured with a mechanized gait carpet at the MOS and three-dimensional motion analyses and in-ground force plates in the Motor Development and Motor Control Laboratories. RESULTS: Linear regression analyses on data from the MOS confirmed that as age increases, step length increases. With a linear mixed effect regression model, we found that individuals who took longer steps had higher arches as measured by the KI. However, this relationship was no longer significant when only adults were included in the model. A model restricted to children found that amongst this sample, those with higher CSI and higher KI values take longer relative step lengths. Data from the Motor Development and Motor Control Laboratories showed that both CSI and KI added to the prediction; children with lower anterior ground reaction forces had higher CSI and higher KI values. Arch height indices were correlated with navicular height. CONCLUSIONS: These results suggest that more than one measure of the arch may be needed elucidate the relationship between arch height and gait.K12 HD055931 - NICHD NIH HHS; K12HD055931 - NICHD NIH HH
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