1,433 research outputs found
Anesthesia and cognitive performance in children: No evidence for a causal relationship. Are the conclusions justified by the data?
Anesthesia and cognitive performance in children: No evidence for a causal relationship. Are the conclusions justified by the data?
Lectins as markers for tubule regions in the kidney of Squalus acanthias, with further observations on SGLT2 immunohistochemistry
Biology and management of Japanese beetle
Abstract supplied by cataloger."This publication is partially funded by a USDA NIFA grant in the Crop Protection and Pest Management Program."An informational article about how to identify and manage Japanese beetles.Written by: Kelsey J. Benthall (GRA, Division of Plant Sciences, University of Missouri), Emily R. Althoff (GRA, Division of Plant Sciences, University of Missouri), Kevin B. Rice (Assistant Professor, Division of Plant Sciences, University of Missouri)New 7/2
The genetic and environmental contributions to attention deficit hyperactivity disorder as measured by the Conners' Rating Scales-revised
Objective: The majority of published reports on twin studies of attention deficit hyperactivity disorder (ADHD) have indicated robust additive genetic influences and unique environmental influences. These studies typically used DSM ADHD symptoms collected by telephone or interviews with mothers. The purpose of this study was to test the genetic architecture of ADHD by using the ADHD index from Conners' Rating Scales - Revised. Method: From the Conners' scale forms, data for the ADHD index were collected from the mothers of 1,595 7-year-old twin pairs from the Netherlands Twin Registry. Rates of ADHD diagnoses were computed by using Conners' gender- and age-specific cutoff points. Contributions from additive, dominant, unique environmental, interaction, and gender effects were computed by using gender-genetic models. Results: The prevalence of ADHD across the sample of 7-year-old twin pairs was about 4% according to the mothers' reports, consistent with other reported rates of ADHD. However, using the gender norms provided with the ADHD index, the authors found slightly higher rates of ADHD in girls than previously reported. Genetic analyses yielded a model that includes genetic dominance (48%), additive genetic factors (30%), and unique environmental factors (22%). Conclusions: The ADHD index from Conners' Rating Scales - Revised identified an appropriate percentage of children across this epidemiologic twin sample as being at risk for ADHD. The results of the genetic analyses are consistent with prior reports that ADHD is predominantly influenced by genetic factors that are both dominant and additive
Arrangement of Elastic Fibres in the Integument of Domesticated Mammals
The hairy skin of important domesticated mammals (12 species) was studied with scanning electron microscopy, transmission electron microscopy, laser scanning microscopy, and several light microscopical methods, to obtain more information about three-dimensional elastic fibre arrangement. It was obvious that there is a basic construction scheme of the elastic fibre meshwork as present in the upper and mid-dermis, with special regard to the size, number, and grouping of hair follicles. In the densely-haired species, in particular, a typical elastic mat with horizontal fibres is formed. In many of the sparsely-haired animals, the upper and mid-dermis show a sponge-like elastic system. In the rather massive, collagen-rich skin of large species, the lower two thirds of the dermis without hair follicles only possess a loosely-structured elastic network, but thick elastic sheets are found at the border zone with the hypodermis.
Specific features appear with regard to the type of mechanical strain exerted, different body regions, varying hair follicle density, or as connected with the anchoring of the hair follicle complex, blood vessels, and nerves
An SU(3) model for octet baryon and meson fragmentation
The production of the octet of baryons and mesons in e^+ e^- collisions is
analysed, based on considerations of SU(3) symmetry and a simple model for
SU(3) symmetry breaking in fragmentation functions. All fragmentation
functions, D_q^h(x, Q^2), describing the fragmentation of quarks into a member
of the baryon octet (and similarly for fragmentation into members of the meson
octet) are expressed in terms of three SU(3) symmetric functions, \alpha(x,
Q^2), \beta(x, Q^2), and \gamma(x, Q^2). With the introduction of an SU(3)
breaking parameter, \lambda, the model is successful in describing
hadroproduction data at the Z pole. The fragmentation functions are then
evolved using leading order evolution equations and good fits to currently
available data at 34 GeV and at 161 GeV are obtained.Comment: 24 pages LaTeX file including 11 postscript figure file
Irreversible time-dependent rheological behavior of cement slurries : constitutive model and experiments
Over the last few decades, much focus has been given to investigating the reversible rheological behavior of thixotropic materials, but the description of the rheology of materials undergoing an irreversible process is still challenging. In this work, the time-dependent rheological behavior of a cement slurry is investigated. Different rheometric experiments are performed to evaluate the structure breakdown under shear, cement gelation, and curing process. A recently proposed thixotropic elasto-viscoplastic model [de Souza Mendes, Soft Matter 7, 2471-2483 (2011)] is modified to account for irreversible effects, which can be either of a chemical or physical nature, making the current model capable of describing reversible and irreversible processes with a single structure parameter. The parameters of the model are estimated from constant shear rate tests and from the flow curve of the fresh cement slurry. The model predictions are compared to step-down and step-up in stress experiments, and the results show that the model successfully describes experimental data obtained. Interesting phenomena are observed and discussed, including (i) thixotropic behavior during the dormant period, (ii) shear banding, (iii) irreversible changes in cement slurry rheology after the hydration reactions accelerate, and (iv) the existence of a characteristic time for the transition from a thixotropic-yield-stress material to a solid during curing. The predictive capability of the new model includes bifurcation, shear banding, stress overshoots, effects of chemical reactions, and irreversible shear degradation. It is argued that the ideas employed in the present work can be used to incorporate irreversible effects into other thixotropic models, giving rise to the possibility of describing the transient rheological behavior of complex materials in an unprecedented fashion. (c) 2019 The Society of Rheology
Photon Structure and Quantum Fluctuation
Photon structure derives from quantum fluctuation in quantum field theory to
fermion and anti-fermion, and has been an experimentally established feature of
electrodynamics since the discovery of the positron. In hadronic physics, the
observation of factorisable photon structure is similarly a fundamental test of
the quantum field theory Quantum Chromodynamics (QCD). An overview of
measurements of hadronic photon structure in e+e- and ep interactions is
presented, and comparison made with theoretical expectation, drawing on the
essential features of photon fluctuation into quark and anti-quark in QCD.Comment: 29 pages, 15 figures, to appear in Philosophical Transactions of the
Royal Society of London (Series A: Mathematical, Physical and Engineering
Sciences
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