3,960 research outputs found

    The thermo-mechanical performance of glass-fibre reinforced Polyamide 66 during glycol-water hydrolysis conditioning

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    Injection moulded glass-fibre reinforced polyamide 66 composites based on two glass fibre products with different sizing formulations and unreinforced polymer samples have been characterised by dynamic mechanical analysis and unnotched Charpy impact testing both dry as moulded and during conditioning in a glycol-water mixture at 70°C for a range of times up to 400 hours. Simultaneously weight and dimension changes of these materials have been recorded. The results reveal that hydrothermal ageing in glycol-water mixtures causes significant changes in the thermo-mechanical performance of these materials. It is shown that mechanical performance obtained after conditioning at different temperatures can be superimposed when considered as a function of the level of fluid absorbed by the composite polymer matrix

    Unitarity Restoration in the Presence of Closed Timelike Curves

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    A proposal is made for a mathematically unambiguous treatment of evolution in the presence of closed timelike curves. In constrast to other proposals for handling the naively nonunitary evolution that is often present in such situations, this proposal is causal, linear in the initial density matrix and preserves probability. It provides a physically reasonable interpretation of invertible nonunitary evolution by redefining the final Hilbert space so that the evolution is unitary or equivalently by removing the nonunitary part of the evolution operator using a polar decomposition.Comment: LaTeX, 17pp, Revisions: Title change, expanded and clarified presentation of original proposal, esp. with regard to Heisenberg picture and remaining in original Hilbert spac

    Duchenne Muscular Dystrophy and Brain Function

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    Muscular dystrophies have historically been characterised according to clinical criteria, however in the genomic age the muscular dystrophies are now subdivided into groups according to the primary gene defect. Currently identified are 29 different loci and encoded proteins, giving rise to 34 distinct forms of muscular dystrophy (Dalkilic & Kunkel 2003;Hsu 2004). The majority of these types of muscular dystrophy are caused by perturbations of different components of the dystrophin-glycoprotein complex (DGC) an integral component of the cellular cytoskeleton (see below). Dystrophin is the largest component of the DGC and is absent in Duchenne muscular dystrophy (DMD), and severely truncated with decreased levels in Becker muscular dystrophy (BMD) (Hoffman & Kunkel 1989). DMD and the allelic BMD are the most common forms of muscular dystrophy in humans and together they are termed dystrophinopathies (Kingston et al. 1984; Shaw & Dreifuss1969). DMD alone accounts for approximately 80% of all the myopathies in the muscular dystrophy group (Culligan et al. 1998).The dystrophin gene is the second largest described to date, totalling 1.5% of the X chromosome, 0.1% of the entire genome. The DMD gene is 99% introns, with a coding sequence of 86 exons (including the promoters) and remains the only known human metagene (Blake et al. 2002; Burmeister et al. 1988; Hamed & Hoffmann 2006; Kenwrick et al. 1987; Koenig et al. 1987; Kunkel et al. 1986; Muntoni et al. 2003; Roberts et al. 1993; Smith et al. 2006; Van Ommen et al. 1987; Wallis et al. 2004). Dystrophin wasdemonstrated to be localised at the sarcolemma in human skeletal muscle after its’ genetic characterisation (Arahata et al. 1988; Sugita et al. 1988; Zubrzycka-Gaarn et al. 1988). This discovery was followed by a report of dystrophin messenger RNA in brain, with the protein being specifically localised at postsynaptic densities (PSD) in the CNS, in particular in the hippocampus, cerebral cortex and in cerebellar Purkinje cells (PC) (Chamberlain et al. 1988; Chelly et al. 1988, 1989; Lidov et al. 1990, Nudel et al. 1988)

    Clinical Utility of the MMPI-2-RF Hierarchical Description:An Illustration in Cluster C Personality Disorder Patients

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    Several studies have addressed the associations between the Minnesota Multiphasic Personality Inventory-2 Restructured form (MMPI-2-RF; Ben-Porath &amp; Tellegen, 2008) scale scores and the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5; American Psychiatric Association, 2013) Section II personality disorder (PD) criterion counts. While these studies showed which variables were associated with the PDs as well as their combined predictive potency, no information is available on mean patterns of elevation associated with these conditions. To illustrate how the MMPI-2-RF information may amplify categorical diagnostic information, we describe the mean RF profiles of a psychiatric sample with a Cluster C PD diagnosis. PD classification was based on the Structured Clinical Interview for the DSM-IV (SCID-II). Patterns of elevation across the three levels of the MMPI-2-RF scale sets were consistently in line with theoretical expectation. In addition, elevated scores on somatic/cognitive scales were noted. It is concluded that the MMPI-2-RF can enhance DSM Personality disorder model description.</p

    Performance of early weaned calves fed lasalocid

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    Twenty-two newborn, bull calves were used to determine the effects of lasalocid on growth and feed intake of early-weaned calves from week 1 to 12. Calves were assigned to lasalocid or control groups on day 3. Lasalocid-fed group received lasalocid in milk from day 4 to 7 and in milk and pre-starter from days 7 to 14 and in starter feed from weeks 2 to 12. Lasalocid-fed calves had a significantly higher feed consumption and greater weight gain than calves that did not receive lasalocid. The difference became apparent only after 6 wk of age. Lasalocid appears to be a beneficial feed additive for newborn calves

    Centennial-scale vegetation and North Atlantic Oscillation changes during the Late Holocene in the southern Iberia

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    High-reso CE to lution pollen analysis, charcoal, non-pollen palynomorphs and magnetic susceptibility have been analyzed in the sediment record of a peat bog in Sierra Nevada in southern Iberia. The study of these proxies provided the reconstruction of vegetation, climate, fire and human activity of the last ∼4500 cal yr BP. A progressive trend towards aridification during the late Holocene is observed in this record. This trend is interrupted by millennial- and centennial-scale variability of relatively more humid and arid periods. Arid conditions are recorded between ∼4000 and 3100 cal yr BP, being characterized by a decline in arboreal pollen and with a spike in magnetic susceptibility. This is followed by a relatively humid period from ∼3100 to 1600 cal yr BP, coinciding partially with the Iberian-Roman Humid Period, and is indicated by the increase of Pinus and the decrease in xerophytic taxa. The last 1500 cal yr BP are characterized by several centennial-scale climatic oscillations. Generally arid conditions from ∼450 to 1300 CE, depicted by a decrease in Pinus and an increase in Artemisia, comprise the Dark Ages and the Medieval Climate Anomaly. Since ∼ 1300 to 1850 CE pronounced oscillations occur between relatively humid and arid conditions. Four periods depicted by relatively higher Pinus coinciding with the beginning and end of the Little Ice Age are interrupted by three arid events characterized by an increase in Artemisia. These alternating arid and humid shifts could be explained by centennial-scale changes in the North Atlantic Oscillation and solar activity

    Effect of ruminal protozoa on performance of early-weaned calves

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    Twenty newborn bull calves assigned to two groups, protozoa-free or protozoa-inoculated, were used to determine the effects of ruminal protozoa on performance of early weaned calves. Calves in the protozoa group were inoculated via stomach tube with a suspension of ruminal protozoa at weekly intervals until a viable population was established. Calves were evaluated weekly for weight gain and feed intake. Feed intake and weight gain were not significantly different between the groups but tended to be higher in protozoa-inoculated than protozoa-free calves.; Dairy Day, 1987, Kansas State University, Manhattan, KS, 1987

    Performance of early weaned calves fed lasalocid

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    Twenty-two newborn, bull calves were used to determine the effects of lasalocid on growth and feed intake of early-weaned calves from week 1 to 12. Calves were assigned to lasalocid or control groups on day 3. Lasalocid-fed group received lasalocid in milk from day 4 to 7 and in milk and pre-starter from days 7 to 14 and in starter feed from weeks 2 to 12. Lasalocid-fed calves had a significantly higher feed consumption and greater weight gain than calves that did not receive lasalocid. The difference became apparent only after 6 wk of age. Lasalocid appears to be a beneficial feed additive for newborn calves.; Dairy Day, 1987, Kansas State University, Manhattan, KS, 1987

    An Ensemble Kalman-Particle Predictor-Corrector Filter for Non-Gaussian Data Assimilation

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    An Ensemble Kalman Filter (EnKF, the predictor) is used make a large change in the state, followed by a Particle Filer (PF, the corrector) which assigns importance weights to describe non-Gaussian distribution. The weights are obtained by nonparametric density estimation. It is demonstrated on several numerical examples that the new predictor-corrector filter combines the advantages of the EnKF and the PF and that it is suitable for high dimensional states which are discretizations of solutions of partial differential equations.Comment: ICCS 2009, to appear; 9 pages; minor edit

    Prior events predict cerebrovascular and coronary outcomes in the PROGRESS trial

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    &lt;p&gt;&lt;b&gt;Background and Purpose:&lt;/b&gt; The relationship between baseline and recurrent vascular events may be important in the targeting of secondary prevention strategies. We examined the relationship between initial event and various types of further vascular outcomes and associated effects of blood pressure (BP)–lowering.&lt;/p&gt; &lt;p&gt;&lt;b&gt;Methods:&lt;/b&gt; Subsidiary analyses of the Perindopril Protection Against Recurrent Stroke Study (PROGRESS) trial, a randomized, placebo-controlled trial that established the benefits of BP–lowering in 6105 patients (mean age 64 years, 30% female) with cerebrovascular disease, randomly assigned to either active treatment (perindopril for all, plus indapamide in those with neither an indication for, nor a contraindication to, a diuretic) or placebo(s).&lt;/p&gt; &lt;p&gt;&lt;b&gt;Results:&lt;/b&gt; Stroke subtypes and coronary events were associated with 1.5- to 6.6-fold greater risk of recurrence of the same event (hazard ratios, 1.51 to 6.64; P=0.1 for large artery infarction, P&#60;0.0001 for other events). However, 46% to 92% of further vascular outcomes were not of the same type. Active treatment produced comparable reductions in the risk of vascular outcomes among patients with a broad range of vascular events at entry (relative risk reduction, 25%; P&#60;0.0001 for ischemic stroke; 42%, P=0.0006 for hemorrhagic stroke; 17%, P=0.3 for coronary events; P homogeneity=0.4).&lt;/p&gt; &lt;p&gt;&lt;b&gt;Conclusions:&lt;/b&gt; Patients with previous vascular events are at high risk of recurrences of the same event. However, because they are also at risk of other vascular outcomes, a broad range of secondary prevention strategies is necessary for their treatment. BP–lowering is likely to be one of the most effective and generalizable strategies across a variety of major vascular events including stroke and myocardial infarction.&lt;/p&gt
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