6,369 research outputs found
Phase behaviour and dynamics in primitive models of molecular ionic liquids
The phase behaviour and dynamics of molecular ionic liquids are studied using
primitive models and extensive computer simulations. The models account for
size disparity between cation and anion, charge location on the cation, and
cation-shape anisotropy, which are all prominent features of important
materials such as room-temperature ionic liquids. The vapour-liquid phase
diagrams are determined using high-precision Monte Carlo simulations, setting
the scene for in-depth studies of ion dynamics in the liquid state. Molecular
dynamics simulations are used to explore the structure, single-particle
translational and rotational autocorrelation functions, cation orientational
autocorrelations, self diffusion, viscosity, and frequency-dependent
conductivity. The results reveal some of the molecular-scale mechanisms for
charge transport, involving molecular translation, rotation, and association.Comment: 15 pages, 7 figure
Effect of Media and Estrogen on Morphological Change in Candida albicans
Introduction:
Candida albicans (C. albicans), an opportunistic pathogen, lives symbiotically within the intestine of its human host. Temperature and chemical factors have been shown to induce a morphological change in C. albicans from yeast to filamentous form turning C. albicans pathogenic. In this study, we investigated the intestinal cues that might be responsible for the change. We found that different solid media impact the morphological phenotype so we focused on characterizing these before further testing. We tested Estradiol (E2) because of its known linkage to sepsis and higher levels during infections. Experiments were conducted to compare solid agar plates of YEPD, Minimal Media (MM), and Spider Media (SP) for C. albicans growth to choose the best one for further testing with E2 and other factors that could be prone to causing morphological changes.
Methods:
C. albicans was inoculated through streak method on different solid media (YEPD, MM, SP) and incubated at 30℃. The effect of 0.1nM E2 on C. albicans morphology was also tested. Morphological changes were assayed through bright-field microscopy.
Results:
Using the three different medias, we found three distinctive phenotypes: A, B, and C. Out of 6 experiments of 14 MM plates, the expressed phenotype was 86% A and 14% inconclusive of the time. 8 experiments of 17 SP plates showed 100% of phenotype B. 6 experiments of 14 YEPD plates presented phenotype C 92% of the time and 8% inconclusive. For E2 trials, 2 experiments, 6 MM plates showed 50% phenotype A and 50% inconclusive. 4 experiments, 10 SP plates had phenotype B 100%. YEPD 2 experiments, 2 plates had phenotype C at 100%.
Conclusion:
We have established experimental conditions of media controls for further testing whether E2 and other cues, such as inflammatory cytokines, have inhibitory or positive effects on the growth of C. albicans
Model of Thermal Wavefront Distortion in Interferometric Gravitational-Wave Detectors I: Thermal Focusing
We develop a steady-state analytical and numerical model of the optical
response of power-recycled Fabry-Perot Michelson laser gravitational-wave
detectors to thermal focusing in optical substrates. We assume that the thermal
distortions are small enough that we can represent the unperturbed intracavity
field anywhere in the detector as a linear combination of basis functions
related to the eigenmodes of one of the Fabry-Perot arm cavities, and we take
great care to preserve numerically the nearly ideal longitudinal phase
resonance conditions that would otherwise be provided by an external
servo-locking control system. We have included the effects of nonlinear thermal
focusing due to power absorption in both the substrates and coatings of the
mirrors and beamsplitter, the effects of a finite mismatch between the
curvatures of the laser wavefront and the mirror surface, and the diffraction
by the mirror aperture at each instance of reflection and transmission. We
demonstrate a detailed numerical example of this model using the MATLAB program
Melody for the initial LIGO detector in the Hermite-Gauss basis, and compare
the resulting computations of intracavity fields in two special cases with
those of a fast Fourier transform field propagation model. Additional
systematic perturbations (e.g., mirror tilt, thermoelastic surface
deformations, and other optical imperfections) can be included easily by
incorporating the appropriate operators into the transfer matrices describing
reflection and transmission for the mirrors and beamsplitter.Comment: 24 pages, 22 figures. Submitted to JOSA
Genome-wide linkage analysis for aggressive prostate cancer in Utah high risk pedigrees
posterResearch has consistently shown that genetics plays a critical role in prostate cancer (CaP) development, but the identification of CaP genes has proven to be very difficult. Hereditary prostate cancer is a complex disease involving numerous genes and variable phenotypic expression. This heterogeneity has led researchers to pursue genes associated with alternative phenotypes for CaP, such as tumor aggressiveness. Several recent linkage studies have used clinical and pathological data to define CaP aggressiveness as a qualitative trait. The International Consortium for Prostate Cancer Genetics (ICPCG) recently completed such an analysis using pooled data from 11 member institutions. This analysis required all families be small to moderate in size in order to facilitate standard linkage analysis software. Hence, although the ICPCG analysis included data from the Utah prostate cancer pedigree resource, the Utah pedigrees were not analyzed in their complete form. Specifically, pedigrees were divided and trimmed before analysis, which reduced the power of the analysis to detect predisposition loci. Here we present the results of a genome-wide scan for aggressive prostate cancer predisposition loci utilizing the full Utah pedigrees
SumLINK statistic for linkage analysis: application to the ICPCG pooled linkage resource
posterWe propose a novel, genome-wide, linkagebased statistic, "sumLINK," for identification of disease susceptibility loci. Our approach focuses primarily on "linked" pedigrees (those with pedigree-specific LOD ? 0.588; equivalent to unadjusted p ? 0.05) to identify regions of extreme consistency across powerful pedigrees. The sumLINK statistic is simply the sum of multipoint LOD scores for linked pedigrees at a given point in the genome. The genetic factors underlying many complex human traits are poorly understood. Linkage findings are often difficult to replicate, and localizing the genes responsible for linkage signals is challenging. We believe that focusing on individually powerful pedigrees may give the greatest opportunity to identify and localize true susceptibility loci and the underlying genes
Genetic susceptibility of prostate cancer: genome-wide screen of ""non-aggressive"" disease
posterResearch has consistently shown that genetics plays a critical role in prostate cancer (CaP) development, but the identification of CaP genes has proven to be very difficult. Hereditary prostate cancer is a complex disease believed to involve numerous genes and variable penetrance. It has been proposed that studying alternative, highly homogenous phenotypes related to CaP may be a solution for overcoming the apparent heterogeneity that has hindered the identification of susceptibility genes. Several recent studies have applied this idea to "aggressive" or "clinically significant" cases of CaP. Using the resources of the Utah Population Database, we identified two phenotypes often associated with non-aggressive disease that show significant familiality. We present those results here
Survey of excess familiality in prostate cancer
posterProstate cancer (PCa) is the most commonly diagnosed cancer among men, and has long been recognized to occur in familial clusters. However, identification of genes predisposing individuals to prostate cancer has been difficult. Putative PCa predisposition loci identified by genetic linkage have been reported on almost all chromosomes, but successful confirmation reports have been rare. PCa is a complex disease likely involving multiple genes and variable phenotypic expression. As a step toward understanding PCa heterogeneity, we used the resources of the Utah Population Database to review several PCa-related phenotypes for excess familiality. PCa subgroups that can be shown to have a strong familial component become candidates for linkage analysis and other genetic testing to determine the genetic basis for the observed phenotype
Application of NASTRAN/COSMIC in the analysis of ship structures to underwater explosion shock
The application of NASTRAN/COSMIC in predicting the transient motion of ship structures to underwater, non-contact explosions is discussed. Examples illustrate the finite element models, mathematical formulations of loading functions and, where available, comparisons between analytical and experimental results
Retrieval-, Distributed-, and Interleaved Practice in the Classroom:A Systematic Review
Three of the most effective learning strategies identified are retrieval practice, distributed practice, and interleaved practice, also referred to as desirable difficulties. However, it is yet unknown to what extent these three practices foster learning in primary and secondary education classrooms (as opposed to the laboratory and/or tertiary education classrooms, where most research is conducted) and whether these strategies affect different students differently. To address these gaps, we conducted a systematic review. Initial and detailed screening of 869 documents found in a threefold search resulted in a pool of 29 journal articles published from 2006 through June 2020. Seventy-five effect sizes nested in 47 experiments nested in 29 documents were included in the review. Retrieval- and interleaved practice appeared to benefit students’ learning outcomes quite consistently; distributed practice less so. Furthermore, only cognitive Student*Task characteristics (i.e., features of the student’s cognition regarding the task, such as initial success) appeared to be significant moderators. We conclude that future research further conceptualising and operationalising initial effort is required, as is a differentiated approach to implementing desirable difficulties
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