Initial investigation of the wavelength dependence of optical properties measured with a new multi-pass Aerosol Extinction Differential Optical Absorption Spectrometer (AE-DOAS)

Atmospheric aerosols directly affect climate by scattering and absorbing radiation. The magnitude of the impact is dependent upon the wavelength of light, but is often estimated near 550 nm. When light scattering and absorption by aerosols is approximated, the wavelength dependence of the refractive index for specific components is lost. As a result, climate models would have inherent uncertainties for aerosol contributions to radiative forcing when considering the entire solar spectrum. An aerosol extinction differential optical absorption spectrometer has been developed to directly measure aerosol extinction at mid-ultraviolet to near infrared wavelengths. The instrument consists of a spectrometer coupled to a closed White-type multi-pass gas cell with an adjustable path length of up to approximately 20 m. Laboratory measurements of various gases are compared with known absorption cross sections. Additionally, the extinction of monodisperse samples of polystyrene latex spheres are measured and compared to Mie theory generated with refractive index values from the literature to validate the new instrument. The polystyrene experiments also emphasize the ability of the new instrument to retrieve the wavelength dependent refractive index, especially in the ultraviolet wavelength regions where variability is expected. The spectrometer will be a significant advancement for determining wavelength dependent complex refractive indices in future laboratory studies as well as provide the ability to monitor ambient aerosol light extinction

Interactions between nutrition and gastrointestinal infections with parasitic nematodes in goats

Parasitic nematodes of the digestive tract remain one of the main constraints to goat production both in temperate and tropical countries. The usual mode of control of these gastrointestinal nematodes (GIN) based on the repeated use of anthelmintics is now strongly questioned because of the increasing development of resistance to these molecules. Among the alternative methods to anthelmintics currently available, the manipulation of host nutrition in order to improve the host resistance and/or resilience to parasitic infections seems to represent one of the most promising options to reduce the dependence on conventional chemotherapy and to favour the sustainable control of gastro intestinal nematode infections. This paper will review the available information on the interactions between nutrition and nematode parasitism in dairy or meat goats both in temperate and tropical conditions. It will refer to quantitative aspects of the diet (influence of the protein and/or energy parts) as well as to qualitative components (effects of plant secondary metabolites on worm biology) and will discuss the specificities of goats in regard of theses interactions

Backward error analysis and the substitution law for Lie group integrators

Butcher series are combinatorial devices used in the study of numerical methods for differential equations evolving on vector spaces. More precisely, they are formal series developments of differential operators indexed over rooted trees, and can be used to represent a large class of numerical methods. The theory of backward error analysis for differential equations has a particularly nice description when applied to methods represented by Butcher series. For the study of differential equations evolving on more general manifolds, a generalization of Butcher series has been introduced, called Lie--Butcher series. This paper presents the theory of backward error analysis for methods based on Lie--Butcher series.Comment: Minor corrections and additions. Final versio

Explaining the Frequency of Alcohol Consumption in a Conflict Zone: Jews and Palestinians in Israel

Experiencing stress and exposure to terrorism may have an adverse effect on health risk behaviors. Few studies have examined alcohol use among adults living in Israel under chronic, stressful terrorism-related conditions. In this study, we examined the relationships of demographics, past stressful events, and terrorism exposure to the frequency of alcohol use and the mediating roles of depressive and post-traumatic stress disorder (PTSD) symptoms. We used three waves of data from a 2007–2008 nationally representative sample of Jewish and Palestinian adults in Israel. We assessed past stressful events, in addition to direct and indirect exposures to terrorism. Results indicated that past stressful events and exposure to terrorism were not directly associated with alcohol use, but were indirectly associated and mediated by depressive and PTSD symptomology. Mental health symptoms were differentially associated with alcohol use. More frequent drinking was mediated by higher levels of depression, including for women and Palestinians; however, PTSD symptom severity was related to less frequent drinking. Mental health may play a prominent role in the frequency of alcohol use among adults exposed to terrorism in Israel. Alcohol use, as a coping mechanism, may differ by demographic characteristics (gender and ethnicity) and psychological symptomology for adults living in a conflict zone in Israel

Going Beyond the One-Shot: Spiraling Information Literacy Across Four Year

Many institutions overwhelm the first year seminar with “one-shot” library instruction sessions, which are not necessarily linked to any form of assignment or assessment. So how can librarians maintain information literacy instruction throughout a student\u27s academic career? Data collected by the Rivier University librarians showcases the ability to implement information literacy more effectively by streamlining and leveling it out over a four-year period

Asymptotic solvers for ordinary differential equations with multiple frequencies

We construct asymptotic expansions for ordinary differential equations with highly oscillatory forcing terms, focusing on the case of multiple, non-commensurate frequencies. We derive an asymptotic expansion in inverse powers of the oscillatory parameter and use its truncation as an exceedingly effective means to discretize the differential equation in question. Numerical examples illustrate the effectiveness of the method

The Metabolism of Alcohol: Risk and Protective Factors

Purpose: Abstract for poster submission to VCU Poster Symposium for Undergraduate Research and Creativity Title: The Metabolism of Alcohol: Risk and Protective Factors Background: In 2002, it was reported by the National Institutes of Health that 60.3% of college aged students (18-22) drank alcohol in the past month of being asked, as compared to 51.9% of those not in college. They also found that 20% of college students met the criteria for at least one alcohol use disorder (AUDs)1. Many genes have been linked to an increased risk for AUDs and how individuals with various ethnic backgrounds respond to alcohol. Genes that metabolize alcohol are obvious candidate genes for alcohol-related phenotypes. The purpose of this presentation is to synthesize information about the key genes involved in alcohol metabolism, as documented in the literature. Methods: The information about each gene was found through a literature search using databases including PubMed, Google Scholar, and cited references from relevant papers. For database searches, the names of the genes were used as well as terms such as AUDs, alcohol metabolism, and alcohol and aldehyde dehydrogenase. The focus of the presentation will be relevant to college-aged students, but rely on research done in college and adult populations due to a lack of sufficient college- aged gene-based studies in this area. Results: Alcohol metabolism genes affect how individuals process and respond to alcohol. The main genes that have been studied are alcohol and aldehyde dehydrogenase genes. Alcohol dehydrogenase genes, like ADH1B and ADH1C, first metabolize ethanol (alcohol) into the by-product acetaldehyde and acetaldehyde is then metabolized by aldehyde dehydrogenase genes, like ALDH2, into the waste product acetate2. Many of the adverse effects associated with alcohol consumption are due to the build up of acetaldehyde. Some of these effects include facial blushing, nausea, headaches, and other similar alcohol sensitivity symptoms3,6. Acetaldehyde builds up in an individuals body after alcohol consumption if he or she has a super- active isoenzyme from the ADH1B and/or ADH1C genes and/or a slow ALDH2 enzyme. Individuals with the super-active alcohol dehydrogenase isoenzyme and slow aldehyde dehydrogenase enzyme are less likely to develop AUDs due to the negative effects from excess acetaldehyde in the body4,5,6. However, this also implies that individuals who do not exhibit the described protective phenotype are more likely to endorse increased drinking behaviors and AUDs. Spit for Science: the VCU Student Survey is currently investigating these genes and their association with alcohol consumption and alcohol use disorder symptoms. Due to the diverse nature of the sample, the researchers are able to explore ethnic differences in these alcohol metabolism genes and their effects. Implications: In general, the more public knowledge about these genes and research findings, the more at-risk individuals can get help and diagnosis. A better understanding of aggregate effects of alcohol metabolism genes, as well as more information regarding ethnic differences in the distribution of genetic variants which impact alcohol processing, will assist researchers and health professionals working with those at risk for AUDs.https://scholarscompass.vcu.edu/uresposters/1137/thumbnail.jp

High-precision measurement of the half-life of 62^{62}Ga

The beta-decay half-life of 62Ga has been studied with high precision using on-line mass separated samples. The decay of 62Ga which is dominated by a 0+ to 0+ transition to the ground state of 62Zn yields a half-life of T_{1/2} = 116.19(4) ms. This result is more precise than any previous measurement by about a factor of four or more. The present value is in agreement with older literature values, but slightly disagrees with a recent measurement. We determine an error weighted average value of all experimental half-lives of 116.18(4) ms.Comment: 9 pages, 5 figures, accepted for publication in PR

Hernie Inguinoscrotale de l’Uretère: Fait Clinique et Revue de la Littérature

la hernie intrascrotale de l’uretère est une situation rare, nous rapportons un cas clinique, compliqué d’hydronéphrose gauche chez un patient de 83ans, l’anomalie avait été reconnue en peropératoire.Mots clés: Hernie, de l’uretère, le scrotum, hydronéphros

Comparison of Near-Infrared Spectroscopy Measured Muscle Metabolism with Predicted Whole-Body Metabolism

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