2995 research outputs found
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Racial, ethnic, and income disparities in air pollution: A study of excess emissions in Texas
No full textObjective: Excess emissions are pollutant releases that occur during periods of startups, shutdowns or malfunctions and are considered violations of the U.S. Clean Air Act. They are an important, but understudied and under-regulated, category of pollution releases given their frequency and magnitude. In this paper, we examine the demographic correlates of excess emissions, using data from industrial sources in Texas. Methods: We conduct two complementary sets of analyses: one at the census tract level and one at the facility level. At the census tract level, we use a multinomial logit model to examine the relationships between racial, ethnic, and income characteristics and the incidence of excess emissions. At the facility level, we first estimate a logit model to examine whether these characteristics are associated with facilities that emit excess emissions, and then, conditional on the presence of excess emissions, we use ordinary least square regression to estimate their correlation with the magnitude of releases. Results: Across our analyses, we find that the percentage of Black population and median household income are positively associated with excess emissions; percentage of college graduate, population density, median housing value, and percentage of owner-occupied housing unit are negatively associated with excess emissions. We, however, have not found a clear and significant relationship between the percentage of Hispanic population and excess emissions
Culture Impacts the Neural Response to Perceiving Outgroups Among Black and White Faces
No full textOutgroup members (e.g., individuals whose racial identity differs from perceivers’) are stigmatized in Eastern and Western cultures. However, it remains an open question how specific cultural influences affect stigmatization. In this study, we assessed whether cultural learning (i.e., social information acquired from the people in one’s environment) associated with Chinese individuals’ relocation to the United States differentiated the response to multiple outgroups. Two types of cultural learning predict diverging responses to outgroups – awareness of stereotypes about different racial outgroups is associated with increased negative affect and cognitive control toward the stereotyped outgroup. Conversely, intergroup contact attenuates those responses, and does so to a greater extent for individuals from Western cultures. As Chinese–Americans would have had more opportunities to have contact with both White and Black individuals (relative to the Chinese participants), we explored their responses to outgroups as well. Because the neural regions associated with stereotyping and intergroup contact have been well-characterized, we used neuroimaging to disentangle these possibilities. Eighteen White American, 18 Chinese–American, and 17 Chinese participants – who had relocated to the United States less than 1 year prior – viewed images of Black and White individuals while undergoing functional magnetic resonance imaging (fMRI). Participants also completed measures of awareness of cultural stereotypes in the United States about Black and White individuals, implicit bias, and experiences with White and Black individuals. Behaviorally, White American and Chinese–American participants had more intergroup contact with either race than did Chinese participants, but there was no effect of participant group on stereotype knowledge or implicit bias. When viewing faces of White (as compared to Black) individuals while undergoing fMRI, White American (relative to Chinese) participants had attenuated activation in regions of the brain associated with cognitive control, including the right dorsolateral prefrontal cortex, dorsal striatum, and ventrolateral prefrontal cortex. Chinese–Americans’ neural response to either race did not differ from White American or Chinese participants. Taken together, outgroup biases seemed to emerge in a culturally-dependent way based on variability in intergroup contact, but not necessarily awareness of stereotypes
Clinical Laboratory Equipment Manufacturer Policies on Highly Hazardous Communicable Diseases
No full textDevelopment of a Split Esterase for Protein-Protein Interaction-Dependent Small-Molecule Activation
No full textSplit reporters based on fluorescent proteins and luciferases have emerged as valuable tools for measuring interactions in biological systems. Relatedly, biosensors that transduce measured input signals into outputs that influence the host system are key components of engineered gene circuits for synthetic biology applications. While small-molecule-based imaging agents are widely used in biological studies, and small-molecule-based drugs and chemical probes can target a range of biological processes, a general method for generating a target small molecule in a biological system based on a measured input signal is lacking. Here, we develop a proximity-dependent split esterase that selectively unmasks ester-protected small molecules in an interaction-dependent manner. Exploiting the versatility of an ester-protected small-molecule output, we demonstrate fluorescent, chemiluminescent, and pharmacological probe generation, each created by masking key alcohol functional groups on a target small molecule. We show that the split esterase system can be used in combination with ester-masked fluorescent or luminescent probes to measure protein–protein interactions and protein–protein interaction inhibitor engagement. We demonstrate that the esterase-based reporter system is compatible with other commonly used split reporter imaging systems for the simultaneous detection of multiple protein–protein interactions. Finally, we develop a system for selective small-molecule-dependent cell killing by unmasking a cytotoxic molecule using an inducible split esterase. Presaging utility in future synthetic biology-based therapeutic applications, we also show that the system can be used for intercellular cell killing via a bystander effect, where one activated cell unmasks a cytotoxic molecule and kills cells physically adjacent to the activated cells. Collectively, this work illustrates that the split esterase system is a valuable new addition to the split protein toolbox, with particularly exciting potential in synthetic biology applications
Detect Camouflaged Spam Content via StoneSkipping: Graph and Text Joint Embedding for Chinese Character Variation Representation
No full textThe task of Chinese text spam detection is very challenging due to both glyph and phonetic variations of Chinese characters. This paper proposes a novel framework to jointly model Chinese variational, semantic, and contextualized representations for Chinese text spam detection task. In particular, a Variation Family-enhanced Graph Embedding (VFGE) algorithm is designed based on a Chinese character variation graph. The VFGE can learn both the graph embeddings of the Chinese characters (local) and the latent variation families (global). Furthermore, an enhanced bidirectional language model, with a combination gate function and an aggregation learning function, is proposed to integrate the graph and text information while capturing the sequential information. Extensive experiments have been conducted on both SMS and review datasets, to show the proposed method outperforms a series of state-of-the-art models for Chinese spam detection
Evidence for a GPR18 Role in Chemotaxis, Proliferation, and the Course of Wound Closure in the Cornea
No full textPURPOSE: We previously showed that cannabinoid-related GPR18 receptors are present in murine corneal epithelium but their function remains unknown. The related CB1 receptors regulate corneal healing, possibly via chemotaxis. We therefore examined a potential role for GPR18 in corneal epithelial chemotaxis and wound healing. METHODS: We examined GPR18 mRNA and protein expression in cornea. We additionally examined the GPR18 action in cultured bovine corneal epithelial cells (bCECs) using Boyden and tracking assays, as well as proliferation and signaling. Finally, we examined wound closure in murine corneal explants. RESULTS: GPR18 mRNA was upregulated with injury in mouse cornea. GPR18 protein was present in basal epithelial cells of the mouse and cow, and redistributed to the wound site upon injury. GPR18 ligand N-arachidonoylglycine (NAGly) induced bCEC chemotaxis. The endocannabinoid arachidonoylethanolamine (AEA) also induced chemotaxis via fatty acid amide hydrolase (FAAH) mediated metabolism to NAGly. GPR18 receptor activation additionally induced bCEC proliferation. In an explant model, the GPR18 antagonist O1918 slowed corneal epithelial cell migration and the rate of corneal wound closure. CONCLUSIONS: Corneal GPR18 activation induced both chemotaxis and proliferation in CECs in vitro, and impacted wound healing. GPR18 may contribute to the maintenance of corneal integrity
Evaluating the stoichiometric trait distributions of cultured bacterial populations and uncultured microbial communities
No full textWe measured the stoichiometric trait distribution of cultured freshwater bacterial populations under different resource conditions and compared them to natural microbial communities sampled from three lakes. Trait distributions showed population differences among growth phases and community differences among lakes that would have been masked by only reporting the mean biomass value. The stoichiometric trait distribution of the environmental isolates changed with P availability, growth phase and genotype, with P availability having the strongest effect. The distribution of biomass ratios within each isolate growth experiment were the most constrained during the stages of rapid growth and commonly had unimodal distributions. In contrast to the population distributions, the distribution of N:P and C:P for a similar number of cells from each of the lake communities had narrower stoichiometric distributions and more commonly exhibited multiple modes. © 2019 Society for Applied Microbiology and John Wiley & Sons Lt
Dendroclimatic Assessment of Ponderosa Pine Radial Growth along Elevational Transects in Western Montana, U.S.A.
No full textPonderosa pine (PP) is the most common and widely distributed pine species in the western United States, spanning from southern Canada to the United States–Mexico border. PP can be found growing between sea level and 3000 meters elevation making them an ideal species to assess the effects of changing climatic conditions at a variety of elevations. Here we compare PP standardized and raw growth responses to climate conditions along an elevational transect spanning 1000 meters in western Montana, U.S.A., a region that experienced a 20th century warming trend and is expected to incur much warmer (3.1–4.5 °C) and slightly drier summers (~0.3 cm decrease per month) by the end on the 21st century. Specifically, we assess if there are climate/growth differences based on relative (i.e., site-specific) and absolute (i.e., combined sites) elevation between groups of trees growing in different elevational classes. We find that values of the Palmer drought severity index (PDSI) in July are most strongly related to radial growth and that within-site elevation differences are a poor predictor of the response of PP to either wet or dry climatic conditions (i.e., years with above or below average July PDSI values). These results suggest that any generalization that stands of PP occurring at their elevational margins are most vulnerable to changing climatic may not be operative at these sites in western Montana. Our results show that when using standardized ring widths, PP growing at the lowest and highest elevations within western Montana exhibit differential growth during extreme climatological conditions with lower-elevation trees outperforming higher-elevation trees during dry years and vice versa during wet years
Reassessing Disparities in Online Learner Student Engagement in Higher Education
No full textOnline learning is the fastest growing segment in U.S. higher education and is increasingly adopted in public and private not-for-profit institutions. While the impact of online learning on educational outcomes is becoming more clear, the literature on its connection with student engagement is sparse. Student engagement measures identify key aspects of the learning process that can improve learning and outcomes like retention and achievement. The few studies investigating the link between online learning and student engagement found positive benefits for online learners compared to face-to-face learners in terms of perceived academic challenge, learning gains, satisfaction, and better study habits. On the other hand, face-to-face learners reported higher levels of environment support, collaborative learning, and faculty interaction. However, these studies did not effectively account for the differences in background characteristics like age, time spent working or caring for dependents, and enrollment status. Further, they did not consider the increasingly large population of students who enroll in both online and face-to-face courses. In our study, we used propensity score matching on the 2015 National Survey of Student Engagement data to account for the disparities in these groups’ demographics variables. After matching, we found that some of the previous literature’s differences diminish or disappear entirely. This suggests differences in supportive environments and learning strategies have more to do with online student characteristics than learning mode. However, online learning still falls well below other modes in terms of collaborative learning and interaction with faculty