664 research outputs found
Optimized Basis Sets for the Environment in the Domain-Specific Basis Set Approach of the Incremental Scheme
Minimal basis sets, denoted DSBSenv, have been developed based on the segmented basis sets of Ahlrichs and co-workers for use as environmental basis set for the domain-specific basis set incremental scheme with the aim of decreasing the CPU requirements of the incremental scheme. The use of this minimal basis within explicitly correlated (F12) methods has been enabled by the optimization of matching auxiliary basis sets for use in density fitting of two-electron integrals and the resolution-of-the-identity. The accuracy of these auxiliary sets has been validated by calculations on a test set containing small- to medium-sized molecules. The errors due to density fitting are about two to four orders of magnitude smaller than the basis set incompleteness error of the DSBSenv orbital basis sets. Additional reductions in computational cost are tested with the reduced DSBSenv basis sets, where the highest angular momentum functions of the DSBSenv auxiliary basis sets have been removed. The optimized and reduced basis sets are used in the framework of the domain-specific basis set of the incremental scheme to decrease the computation time without significant loss of accuracy. The computation times and accuracy of the previously used environmental basis and that optimized in this work is validated with a test set of medium- to large-sized systems. The optimized and reduced DSBSenv basis sets decrease the CPU-time by about 15.4% and 19.4% compared to the old environmental basis and retains the accuracy in the absolute energy with a standard deviation of 0.99 and 1.06 kJ/mol, respectively
The epigenetic impacts of social stress: how does social adversity become biologically embedded?
Epigenetic mechanisms are implicated in the processes through which social stressors erode health in humans and other animals. Here I review progress in elucidating the biological pathways underlying the social gradient in health, with particular emphasis on how behavioral stresses influence epigenomic variation linked to health. The evidence that epigenetic changes are involved in embedding of social status-linked chronic stress is reviewed in the context of current knowledge about behavior within animal dominance hierarchies and the impacts of social position on behaviors that affect health. The roles of epigenetic mechanisms in responses to trauma and the evidence for their involvement in intergenerational transmission of the biological impacts of traumatic stress are also considered. Taken together, the emerging insights have important implications for development of strategies to improve societal health and well-being
Influence of auto-organization and fluctuation effects on the kinetics of a monomer-monomer catalytic scheme
We study analytically kinetics of an elementary bimolecular reaction scheme
of the Langmuir-Hinshelwood type taking place on a d-dimensional catalytic
substrate. We propose a general approach which takes into account explicitly
the influence of spatial correlations on the time evolution of particles mean
densities and allows for the analytical analysis. In terms of this approach we
recover some of known results concerning the time evolution of particles mean
densities and establish several new ones.Comment: Latex, 25 pages, one figure, submitted to J. Chem. Phy
Control of human endometrial stromal cell motility by PDGF-BB, HB-EGF and trophoblast-secreted factors
Human implantation involves extensive tissue remodeling at the fetal-maternal interface. It is becoming increasingly evident that not only trophoblast, but also decidualizing endometrial stromal cells are inherently motile and invasive, and likely contribute to the highly dynamic processes at the implantation site. The present study was undertaken to further characterize the mechanisms involved in the regulation of endometrial stromal cell motility and to identify trophoblast-derived factors that modulate migration. Among local growth factors known to be present at the time of implantation, heparin-binding epidermal growth factor-like growth factor (HB-EGF) triggered chemotaxis (directed locomotion), whereas platelet-derived growth factor (PDGF)-BB elicited both chemotaxis and chemokinesis (non-directed locomotion) of endometrial stromal cells. Supernatants of the trophoblast cell line AC-1M88 and of first trimester villous explant cultures stimulated chemotaxis but not chemokinesis. Proteome profiling for cytokines and angiogenesis factors revealed neither PDGF-BB nor HB-EGF in conditioned media from trophoblast cells or villous explants, while placental growth factor, vascular endothelial growth factor and PDGF-AA were identified as prominent secretory products. Among these, only PDGF-AA triggered endometrial stromal cell chemotaxis. Neutralization of PDGF-AA in trophoblast conditioned media, however, did not diminish chemoattractant activity, suggesting the presence of additional trophoblast-derived chemotactic factors. Pathway inhibitor studies revealed ERK1/2, PI3 kinase/Akt and p38 signaling as relevant for chemotactic motility, whereas chemokinesis depended primarily on PI3 kinase/Akt activation. Both chemotaxis and chemokinesis were stimulated upon inhibition of Rho-associated, coiled-coil containing protein kinase. The chemotactic response to trophoblast secretions was not blunted by inhibition of isolated signaling cascades, indicating activation of overlapping pathways in trophoblast-endometrial communication. In conclusion, trophoblast signals attract endometrial stromal cells, while PDGF-BB and HB-EGF, although not identified as trophoblast-derived, are local growth factors that may serve to fine-tune directed and non-directed migration at the implantation site
Effects of Vitamin D Supplementation
Vitamin D (1,25-dihydroxycholecalciferol) is known to be a fat soluble vitamin. We hypothesized that losing weight would thus cause an increase in serum vitamin D levels. To investigate this, a retrospective chart review was performed in which data including sex, age, race, serum Vitamin D levels, body weight and more, of 200 Rowan SOM Family Medicine patients for up to 6 doctor’s office visits each were collected. These data were then analyzed using Microsoft Excel and IBM SPSS. We found while there was a significant positive correlation between weight loss and serum Vitamin D levels, there was not a significant change in weight. We also found that patients that were taking Vitamin D supplements significantly raised their serum Vitamin D levels. This was not affected by any other variables such as sex, age, or race. We will perform further analysis of the data and hope our findings can be used by clinicians assisting patients losing weight
The Coumadin Ridge: Incidental Finding Mimicking Thrombus on Echocardiogram
The left atrial ridge or “coumadin ridge” is a cardiac anatomic structure located between the left pulmonary vein and the orfice of the left atrial appendage. Historically, patients were misdiagnosed with intra-atrial thrombus and were incorrectly placed on anticoagulation with warfarin, ultimately acquiring the name of the “coumadin ridge”. Fortunately this anatomical variant is now more commonly recognized, however when improperly identified can lead to unnecessary testing, cost, diagnosis anxiety, and inappropriate treatment for the patient. This purpose of this case is to bring awareness to this common clinical dilemma in an attempt to reduce ambiguity and unnecessary workups surrounding this anatomical variant
The strength of negative plant–soil feedback increases from the intraspecific to the interspecific and the functional group level
One of the processes that may play a key role in plant species coexistence and
ecosystem functioning is plant–soil feedback, the effect of plants on
associated soil communities and the resulting feedback on plant performance.
Plant–soil feedback at the interspecific level (comparing growth on own soil
with growth on soil from different species) has been studied extensively,
while plant–soil feedback at the intraspecific level (comparing growth on own
soil with growth on soil from different accessions within a species) has only
recently gained attention. Very few studies have investigated the direction
and strength of feedback among different taxonomic levels, and initial results
have been inconclusive, discussing phylogeny, and morphology as possible
determinants. To test our hypotheses that the strength of negative feedback on
plant performance increases with increasing taxonomic level and that this
relationship is explained by morphological similarities, we conducted a
greenhouse experiment using species assigned to three taxonomic levels
(intraspecific, interspecific, and functional group level). We measured
certain fitness‐related aboveground traits and used them along
literature‐derived traits to determine the influence of morphological
similarities on the strength and direction of the feedback. We found that the
average strength of negative feedback increased from the intraspecific over
the interspecific to the functional group level. However, individual
accessions and species differed in the direction and strength of the feedback.
None of our results could be explained by morphological dissimilarities or
individual traits. Synthesis. Our results indicate that negative plant–soil
feedback is stronger if the involved plants belong to more distantly related
species. We conclude that the taxonomic level is an important factor in the
maintenance of plant coexistence with plant–soil feedback as a potential
stabilizing mechanism and should be addressed explicitly in coexistence
research, while the traits considered here seem to play a minor role
PHYSICAL ASPECTS OF REVERSIBLE INACTIVATION OF ENDOTOXIN *
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74729/1/j.1749-6632.1966.tb52394.x.pd
Physiological Correlates of Volunteering
We review research on physiological correlates of volunteering, a neglected but promising research field. Some of these correlates seem to be causal factors influencing volunteering. Volunteers tend to have better physical health, both self-reported and expert-assessed, better mental health, and perform better on cognitive tasks. Research thus far has rarely examined neurological, neurochemical, hormonal, and genetic correlates of volunteering to any significant extent, especially controlling for other factors as potential confounds. Evolutionary theory and behavioral genetic research suggest the importance of such physiological factors in humans. Basically, many aspects of social relationships and social activities have effects on health (e.g., Newman and Roberts 2013; Uchino 2004), as the widely used biopsychosocial (BPS) model suggests (Institute of Medicine 2001). Studies of formal volunteering (FV), charitable giving, and altruistic behavior suggest that physiological characteristics are related to volunteering, including specific genes (such as oxytocin receptor [OXTR] genes, Arginine vasopressin receptor [AVPR] genes, dopamine D4 receptor [DRD4] genes, and 5-HTTLPR). We recommend that future research on physiological factors be extended to non-Western populations, focusing specifically on volunteering, and differentiating between different forms and types of volunteering and civic participation
Parma consensus statement on metabolic disruptors
A multidisciplinary group of experts gathered in Parma Italy for a workshop hosted by the University of Parma, May 16–18, 2014 to address concerns about the potential relationship between environmental metabolic disrupting chemicals, obesity and related metabolic disorders. The objectives of the workshop were to: 1. Review findings related to the role of environmental chemicals, referred to as “metabolic disruptors”, in obesity and metabolic syndrome with special attention to recent discoveries from animal model and epidemiology studies; 2. Identify conclusions that could be drawn with confidence from existing animal and human data; 3. Develop predictions based on current data; and 4. Identify critical knowledge gaps and areas of uncertainty. The consensus statements
are intended to aid in expanding understanding of the role of metabolic disruptors in the obesity and metabolic disease epidemics, to move the field forward by assessing the current state of the science and to identify research needs on the role of environmental chemical exposures in these diseases. We propose broadening the definition of obesogens to that of metabolic disruptors, to encompass chemicals that play a role in altered susceptibility to obesity, diabetes and related metabolic disorders including metabolic syndrome
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