Development of an integrated BEM approach for hot fluid structure interaction

Significant progress was made toward the goal of developing a general purpose boundary element method for hot fluid-structure interaction. For the solid phase, a boundary-only formulation was developed and implemented for uncoupled transient thermoelasticity in two dimensions. The elimination of volume discretization not only drastically reduces required modeling effort, but also permits unconstrained variation of the through-the-thickness temperature distribution. Meanwhile, for the fluids, fundamental solutions were derived for transient incompressible and compressible flow in the absence of the convective terms. Boundary element formulations were developed and described. For the incompressible case, the necessary kernal functions, under transient and steady-state conditions, were derived and fully implemented into a general purpose, multi-region boundary element code. Several examples were examined to study the suitability and convergence characteristics of the various algorithms

^1H{^(19)F} NOE NMR Structural Signatures of the Insulin R_6 Hexamer: Evidence of a Capped HisB10 Site in Aryl- and Arylacryloyl-carboxylate Complexes

New and improved insulin: ^1H{^(19)F} NOE NMR difference spectra for CF_3-substituted aromatic carboxylates bound at the HisB10 sites of the R_6 human insulin (HI) hexamer show strong NOEs between the CF_3 groups and the LeuB6, AsnB3, and PheB1 sidechains. The NOEs and structural modeling establish that these carboxylates form closed complexes with the HisB10 site capped by the PheB1 rings

Suicide Ideation and Behavior and ATOD Use Among Bisexual High School Students

Research has indicated that sexual minorities have higher prevalence rates for ATOD use and suicide ideation and behavior compared to heterosexual youth. Yet, most studies to date have combined gay, lesbian, and bisexuals into one category. This study sought to assess the uniqueness of bisexuality to assess the risk of ATOD use and suicide ideation and behavior among bisexual high school students. Data for this study were derived from the 2019 Centers for Disease Control’s Youth Risk Behavior Survey (YRBS). Chi-square analysis was conducted to determine the prevalence of ATOD use and suicide ideation and behavior. Logistic regression was then used to estimate the association between ATOD use and suicide ideation and behavior among bisexual adolescents. This study found that ever use an electronic vape product, non-medical use of prescription drugs, and current alcohol and marijuana use were significant predictors for suicide ideation and behavior. Based on our results, we believe that it is important to address the relationship of substance use as a risk factor for suicide and ideation and behavior of bisexual adolescents, as bisexual adolescents may need more emotional support as they come to understand their sexual identity. This article was published Open Access through the CCU Libraries Open Access Publishing Fund. The article was first published in Journal of Substance Use: https://doi.org/10.1080/14659891.2023.226104

Non-medical use of prescription drugs and sexual risk behaviors among depressed adolescents

Non-medical prescription drug abuse is an issue that has plagued adolescents in the United States over the past decade and more. Also, depression is prevalent among our youth with 31% reporting multiple depressive episodes in the past year. As such, the purpose of this study was to assess the relationship between non-medical use of prescription drugs (NMUPD) and sexual behaviors among depressed high school students. Data was derived from the 2015 Youth Risk Behavior Survey (n=15,624). This national study is conducted every odd year, and is a representative sample of high school students in the United States. Logistic regression was conducted to determine the relationship between NMUPD and sexual behavior among students who self-reported a depressive episode. The results of this study found that those student who reported NMUPD and multiple depressive episodes in the past year were significantly more likely to have initiated sexual intercourse, have had sex with 4 or more sexual partners, to be currently sexually active, and to have used alcohol or other drugs before their last sexual encounter. The results of this study seems to indicate that high school students who are depressed may self-medicate with narcotic drugs that were not prescribed to them. In turn, as a result of impaired judgment of narcotic drugs, they may engage in risky sexual behaviors. This research supports calls by other researchers to address issues related to NMUPD early in adolescence. Additionally, these results may extend further the need to develop positive mental health campaigns to identify prolonged negative mood states among adolescents

The Role of Local Policies on Resource Utilization: Timber Harvesting in St. Tammany Parish, Louisiana

Seemingly unrelated regression was used to investigate if the passage of forestry-related ordinances has had an effect upon timber harvesting activities in St. Tammany Parish, Louisiana. Results indicate that a significant negative relationship exists between a $10,000 road bond ordinance and the level of timber harvest in the Parish.Resource /Energy Economics and Policy,

Integrative paleobotany: Affirming the role of fossils in modern plant biology - Introduction and dedication

If you are interested in plant evolution, try this quick exercise: take a phylogenetic tree of the plant kingdom, close your eyes, and point your finger randomly to a node of the phylogeny. Irrespective of the clade to which you are pointing, there is one thing you should know about it: the living representatives of that clade have evolved as a result of a long process in which failed attempts are the rule, and as a result, the diversity of extinct forms accumulated in the fossil record far exceeds that recorded in the extant flora. From this simple concept, Gar W. Rothwell made his career. Because of that, here is a second thing you should know about the plant clade to which you pointed at random: Gar has, more likely than not, contributed information about evolution in that clade at some point in his career. Gar was one of the principal contributors to the revival of paleobotany from a largely descriptive discipline to a vibrant field of investigation at the forefront of modern evolutionary sciences that contributes crucial insights into plant evolution, equal in importance to those provided by genetics and molecular biology. Because of this, the impact of Gar’s scientific contributions reaches far beyond the field of paleobotany, with important implications for wide areas of plant biology, including anatomy and morphology, development, systematics, phylogeny, and evolution. Gar earned a master’s degree in the laboratory of Thomas N. Taylor (University of Illinois at Chicago, 1966) studying Paleozoic seeds in the genus Conostoma (Rothwell and Eggert 1970; Rothwell 1971a). He subsequently earned his PhD degree in the laboratory of Wilson N. Stewart (University of Alberta, 1973), where he reconstructed the plants in the seed fern genus Callistophyton (Rothwell 1972b, 1975, 1980, 1981). His work was instrumental in ushering in studies of fossil plants as whole living organisms, looking at both structure and development. These early experiences launched Gar on a career in plant evolutionary biology that stretched over a half century, during which he occupied positions at the University of Alberta, University of London–Chelsea College, Ohio University, and Oregon State University. Throughout his career, Gar’s scholarly work and contributions have been recognized by numerous awards and honors: the Isabel Cookson Award, the Edgar T. Wherry Award, the Michael A. Cichan Award, the Merit Award of the Botanical Society of America, and honorary membership in the International Organization of Palaeobotany, where he served for 12 years as secretary-treasurer and president.Fil: Escapa, Ignacio Hernán. Museo Paleontológico Egidio Feruglio; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Tomescu, Alexandru M. F.. Humboldt State University. Department of Biological Sciences; Estados UnidosFil: Dunn, Michael T.. Cameron University. Department of Agriculture, Biology and Health Science; Estados UnidosFil: Stockey, Ruth A.. State University of Oregon; Estados Unido

Effect of pH and Monovalent Cations on the Formation of Quinonoid Intermediates of the Tryptophan Synthase α2β2 Complex in Solution and in the Crystal

Quinonoid intermediates play a key role in the catalytic mechanism of pyridoxal 5'-phosphate-dependent enzymes. Whereas the structures of other pyridoxal 5'-phosphate-bound intermediates have been determined, the structure of a quinonoid species has not yet been reported. Here, we investigate factors controlling the accumulation and stability of quinonoids formed at the beta-active site of tryptophan synthase both in solution and the crystal. The quinonoids were obtained by reacting the alpha-aminoacrylate Schiff base with different nucleophiles, focusing mainly on the substrate analogs indoline and beta-mercaptoethanol. In solution, both monovalent cations (Cs(+) or Na(+)) and alkaline pH increase the apparent affinity of indoline and favor accumulation of the indoline quinonoid. A similar pH dependence is observed when beta-mercaptoethanol is used. As indoline and beta-mercaptoethanol exhibit very distinct ionization properties, this finding suggests that nucleophile binding and quinonoid stability are controlled by some ionizable protein residue(s). In the crystal, alkaline pH favors formation of the indoline quinonoid as in solution, but the effect of cations is markedly different. In the absence of monovalent metal ions the quinonoid species accumulates substantially, whereas in the presence of sodium ions the accumulation is modest, unless alpha-subunit ligands are also present. Alpha-subunit ligands not only favor the formation of the intermediate, but also reduce significantly its decay rate. These findings define experimental conditions suitable for the stabilization of the quinonoid species in the crystal, a critical prerequisite for the determination of the three-dimensional structure of this intermediate

Heterodyne detection of multiply scattered monochromatic light with a multipixel detector

International audienceA new technique is presented for measuring the spectral broadening of light that has been multiply scattered from scatterers in motion. In our method the scattered light is detected by a heterodyne receiver that uses a CCD as a multipixel detector. We obtain the frequency spectrum of the scattered light by sweeping the heterodyne local oscillator frequency. Our detection scheme combines a high optical etendue (product of the surface by the detection solid angle) with an optimal detection of the scattered photons (shot noise). Using this technique, we measure, in vivo, the frequency spectrum of the light scattered through the breast of a female volunteer