Virginia Commonwealth University

About: Virginia Commonwealth University is a education organization based out in Richmond, Virginia, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 23822 authors who have published 49587 publications receiving 1787046 citations. The organization is also known as: VCU.

Enhancement of perceived visual intensity by auditory stimuli: A psychophysical analysis

Abstract: Judgments of the intensity of a stimulus are dependent on the level of central nervous system activity it generates. Generally, it is assumed that such judgments are based on activity along modality-specific pathways. Thus, visual intensity judgments would be based on unimodal visual activity. However, many neurons do not fit neatly within modality-specific categories, but can be influenced by more than one sensory modality. Often the “multisensory” effect is quite pronounced. If these multisensory neurons participate in such fundamental functions as perceived intensity, the presence of a nonvisual (i.e., auditory) cue may have a significant effect on the perceived intensity of a visual cue. The results of the present study were consistent with such a hypothesis. A brief, broad-band auditory stimulus was found to significantly enhance the perceived intensity of an LED. The effect was most pronounced at the lowest visual intensities, and was evident regardless of the location of the auditory cue. However, it was present only at the location of visual fixation. Yet, despite the significant influence of the auditory cue, and its differential effect at different visual intensities, a power function that maintains the proportionality among perceived visual intensities was retained.

Differences in vaginal microbiome in African American women versus women of European ancestry

Abstract: Women of European ancestry are more likely to harbour a Lactobacillus-dominated microbiome, whereas African American women are more likely to exhibit a diverse microbial profile. African American women are also twice as likely to be diagnosed with bacterial vaginosis and are twice as likely to experience preterm birth. The objective of this study was to further characterize and contrast the vaginal microbial profiles in African American versus European ancestry women. Through the Vaginal Human Microbiome Project at Virginia Commonwealth University, 16S rRNA gene sequence analysis was used to compare the microbiomes of vaginal samples from 1268 African American women and 416 women of European ancestry. The results confirmed significant differences in the vaginal microbiomes of the two groups and identified several taxa relevant to these differences. Major community types were dominated by Gardnerella vaginalis and the uncultivated bacterial vaginosis-associated bacterium-1 (BVAB1) that were common among African Americans. Moreover, the prevalence of multiple bacterial taxa that are associated with microbial invasion of the amniotic cavity and preterm birth, including Mycoplasma, Gardnerella, Prevotella and Sneathia, differed between the two ethnic groups. We investigated the contributions of intrinsic and extrinsic factors, including pregnancy, body mass index, diet, smoking and alcohol use, number of sexual partners, and household income, to vaginal community composition. Ethnicity, pregnancy and alcohol use correlated significantly with the relative abundance of bacterial vaginosis-associated species. Trends between microbial profiles and smoking and number of sexual partners were observed; however, these associations were not statistically significant. These results support and extend previous findings that there are significant differences in the vaginal microbiome related to ethnicity and demonstrate that these differences are pronounced even in healthy women.

Moving Beyond Global Warming Potentials to Quantify the Climatic Role of Ecosystems

Abstract: For decades, ecosystem scientists have used global warming potentials (GWPs) to compare the radiative forcing of various greenhouse gases to determine if ecosystems have a net warming or cooling effect on climate. On a conceptual basis, the continued use of GWPs by the ecological community may be untenable because the use of GWPs requires the implicit assumption that greenhouse gas emissions occur as a single pulse; this assumption is rarely justified in ecosystem studies. We present two alternate metrics—the sustained-flux global warming potential (SGWP, for gas emissions) and the sustained-flux global cooling potential (SGCP, for gas uptake)—for use when gas fluxes persist over time. The SGWP is generally larger than the GWP (by up to ~40%) for both methane and nitrous oxide emissions, creating situations where the GWP and SGWP metrics could provide opposing interpretations about the climatic role of an ecosystem. Further, there is an asymmetry in methane and nitrous oxide dynamics between persistent emission and uptake situations, producing very different values for the SGWP vs. SGCP and leading to the conclusion that ecosystems that take up these gases are very effective at reducing radiative forcing. Although the new metrics are more realistic than the GWP for ecosystem fluxes, we further argue that even these metrics may be insufficient in the context of trying to understand the lifetime climatic role of an ecosystem. A dynamic modeling approach that has the flexibility to account for temporally variable rates of greenhouse gas exchange, and is not limited by a fixed time frame, may be more informative than the SGWP, SGCP, or GWP. Ultimately, we hope this article will stimulate discussion within the ecosystem science community about the most appropriate way(s) of assessing the role of ecosystems as regulators of global climate.

MicroRNA Expression in Squamous Cell Carcinoma and Adenocarcinoma of the Esophagus: Associations with Survival

Abstract: Purpose: The dismal outcome of esophageal cancer patients highlights the need for novel prognostic biomarkers, such as microRNAs (miRNA). Although recent studies have established the role of miRNAs in esophageal carcinoma, a comprehensive multicenter study investigating different histologic types, including squamous cell carcinoma (SCC) and adenocarcinoma with or without Barrett9s, is still lacking. Experimental Design: miRNA expression was measured in cancerous and adjacent noncancerous tissue pairs collected from 100 adenocarcinoma and 70 SCC patients enrolled at four clinical centers from the United States, Canada, and Japan. Microarray-based expression was measured in a subset of samples in two cohorts and was validated in all available samples. Results: In adenocarcinoma patients, miR-21, miR-223, miR-192, and miR-194 expression was elevated, whereas miR-203 expression was reduced in cancerous compared with noncancerous tissue. In SCC patients, we found elevated miR-21 and reduced miR-375 expression levels in cancerous compared with noncancerous tissue. When comparing cancerous tissue expression between adenocarcinoma and SCC patients, miR-194 and miR-375 were elevated in adenocarcinoma patients. Significantly, elevated miR-21 expression in noncancerous tissue of SCC patients and reduced levels of miR-375 in cancerous tissue of adenocarcinoma patients with Barrett9s were strongly associated with worse prognosis. Associations with prognosis were independent of tumor stage or nodal status, cohort type, and chemoradiation therapy. Conclusions: Our multicenter-based results highlight miRNAs involved in major histologic types of esophageal carcinoma and uncover significant associations with prognosis. Elucidating miRNAs relevant to esophageal carcinogenesis is potentially clinically useful for developing prognostic biomarkers and identifying novel drug targets and therapies. (Clin Cancer Res 2009;15(19):6192–200)

Template-Free Synthesis of a Highly Porous Benzimidazole-Linked Polymer for CO2 Capture and H2 Storage

Abstract: A highly porous benzimidazole-linked polymer (SABET 1172 m2/g) exhibits very high gas selectivity CO2/N2 (70) and CO2/CH4 (10) and can store CO2 (19 wt %, 273 K, 1 bar) and H2 (1.9 wt %, 77 K, 1 bar) with Qst values of 26.7 and 7.9 kJ/mol, respectively.