Tenth Circuit Ruled in Favor of Sex-Plus-Age Claims of Discrimination Under Title VII in the Wake of \u3cem\u3eBostock v. Clayton County\u3c/em\u3e

On July 21, 2020, the U.S. Court of Appeals for the Tenth Circuit in Frappied v. Affinity Gaming Black Hawk, LLC held that sex-plus-age discrimination claims are cognizable under Title VII of the Civil Rights Act of 1964. By taking a stance on the viability of sex-plus-age claims, the Tenth Circuit became the first circuit court to weigh in on the debate among the lower courts. Many federal district courts, relying on the availability of the Age Discrimination in Employment Act to address age discrimination claims, have rejected sex-plus-age claims under Title VII. This Comment argues that the Tenth Circuit’s decision is sound policy and logically follows the Supreme Court’s recent ruling in Bostock v. Clayton County

Effects of Herbicides on Zebrafish Embryo Development and Viability

Environmental contaminants are chemicals of anthropogenic origin that are found in water, soil, and air, and are harmful to a wide variety of organisms (ORD US EPA, 2018-a). One common group of contaminants are herbicides. Though herbicides are used to control unwanted vegetation in agriculture, aquatic organisms and humans may be exposed to these herbicides through run off into streams and rivers, by drinking contaminated water, by consuming treated crops, by direct exposure, or through bioaccumulation. Thus the effect of these herbicides on animals needs further investigation. In this study, I sought to determine whether six different herbicides, which have had minimal testing in animal studies, have teratogenic effects. Thus, I exposed zebrafish embryos (from the blastoderm stage to 4 days post fertilization) to the herbicides, and assessed the effects of each herbicide on embryonic development. My results indicate that all herbicides tested, with the exception of nicosulfuron, led to some form of toxicity, cardiac dysfunction, or other developmental error. For example, exposure of zebrafish embryos to high concentrations of glufosinate-ammonium or thifensulforon-methyl resulted in some embryos exhibiting cardiac dysfunction. However, due to variation in the results at different concentrations, the LD50 (lethal dose 50%) of these herbicides could not be identified. Quizalofop-p-ethyl exposed embryos displayed cardiac dysfunction at the LD50. However, at concentrations slightly higher than the LD50, embryos exhibited a general toxicity that led to 100% mortality. Mecoprop treatment led to variability in mortality at different concentrations. However, within the suspected LD50, mecoprop treated embryos exhibited cardiac dysfunction, as well as a host of other abnormalities: shortened body axis, micropthalmia, curved spine, tail malformation, lack of motility, and abdominal edema. At a range of concentrations, hexazinone treatment resulted in cardiac dysfunction as well as defective pigment cell alignment, shortened body axis, micropthalmia, tail malformation, lack of motility, and abdominal edema. The results of this study provide evidence that one herbicide, nicosulfuron, appears to be safe for zebrafish embryonic development and survival. However, many of these herbicides have teratogenic effects that need to be explored further

Incomplete immunity in a natural animal-microbiota interaction selects for higher pathogen virulence

Incomplete immunity in recovered hosts is predicted to favor more virulent pathogens upon re-infection in the population. The microbiota colonizing animals can generate a similarly long-lasting, partial immune response, allowing for infection but dampened disease severity. We tracked the evolutionary trajectories of a widespread pathogen (Pseudomonas aeruginosa), experimentally passaged through populations of nematodes immune-primed by a natural microbiota member (P. berkeleyensis). This bacterium can induce genes regulated by a mitogen-activated protein kinase (MAPK) signaling pathway effective at conferring protection against pathogen-induced death despite infection. Across host populations, this incomplete immunity selected for pathogens more than twice as likely to kill as those evolved in non-primed (i.e., naive) or immune-compromised (mutants with a knockout of the MAPK ortholog) control populations. Despite the higher virulence, pathogen molecular evolution in immune-primed hosts was slow and constrained. In comparison, evolving pathogens in immune-compromised hosts were characterized by substantial genomic differentiation and attenuated virulence. These findings directly attribute the incomplete host immunity induced from microbiota as a significant force shaping the virulence and evolutionary dynamics of novel infectious diseases

Dual stressors of infection and warming can destabilize host microbiomes

Climate change is causing extreme heating events and intensifying infectious disease outbreaks. Animals harbour microbial communities, which are vital for their survival and fitness under stressful conditions. Understanding how microbiome structures change in response to infection and warming may be important for forecasting host performance under global change. Here, we evaluated alterations in the microbiomes of several wild Caenorhabditis elegans isolates spanning a range of latitudes, upon warming temperatures and infection by the parasite Leucobacter musarum. Using 16S rRNA sequencing, we found that microbiome diversity decreased, and dispersion increased over time, with the former being more prominent in uninfected adults and the latter aggravated by infection. Infection reduced dominance of specific microbial taxa, and increased microbiome dispersion, indicating destabilizing effects on host microbial communities. Exposing infected hosts to warming did not have an additive destabilizing effect on their microbiomes. Moreover, warming during pre-adult development alleviated the destabilizing effects of infection on host microbiomes. These results revealed an opposing interaction between biotic and abiotic factors on microbiome structure. Lastly, we showed that increased microbiome dispersion might be associated with decreased variability in microbial species interaction strength. Overall, these findings improve our understanding of animal microbiome dynamics amidst climate change and epidemics

Diversity and the maintenance of sex by parasites

types: JOURNAL ARTICLECopyright © 2015 European Society For Evolutionary Biology. Journal of Evolutionary BiologyThis is the accepted version of the following article: Diversity and the maintenance of sex by parasites, which has been published in final form at Journal of Evolutionary Biology.http://onlinelibrary.wiley.com/doi/10.1111/jeb.12590/abstractThe Red Queen hypothesis (RQH) predicts that parasite-mediated selection will maintain sexual individuals in the face of competition from asexual lineages. The prediction is that sexual individuals will be difficult targets for coevolving parasites if they give rise to more genetically diverse offspring than asexual lineages. However, increasing host genetic diversity is known to suppress parasite spread, which could provide a short-term advantage to clonal lineages and lead to the extinction of sex. We test these ideas using a stochastic individual-based model. We find that if parasites are readily transmissible, then sex is most likely to be maintained when host diversity is high, in agreement with the RQH. If transmission rates are lower, however, we find that sexual populations are most likely to persist for intermediate levels of diversity. Our findings thus highlight the importance of genetic diversity and its impact on epidemiological dynamics for the maintenance of sex by parasites.NER

Effects of Study Abroad Participation upon Selected Personality Measures

Introduction It is generally felt that studying abroad is a transformative experience for undergraduate students for a multitude of reasons including social skills, the ability to adapt to different surroundings, and character building. Nevertheless, some people do not take advantage of study abroad opportunities. The purpose of this study was to investigate personality characteristics of students who participated in a study abroad program in Germany during the summer of 2016. The Positive and Negative Affect Schedule (PANAS-X; Watson & Clark, 1994) measures of six negative and positive mood states, the Dark Triad (Paulhus and Jones, 2011) which measures Machiavellianism, Narcissism, and Psychopathy, and the Multidimensional Locus of Control Scale (Levenson, 1973) which assesses internal, powerful others, and chance locus of control orientation. Additionally, the Competitive State Anxiety Inventory (CSAI-2R; Cox, Martens, & Russell, 2003) was used to assess anxiety associated with study abroad experiences. Method Participants were 18 female undergraduate students who responded to a booklet concerning collegiate study abroad experiences. The booklet included the above described psychometric measures. SAS statistical analyses were employed to compare pre-trip and post-trip scale scores (correlated t-test). Results PANAS X findings: the participants were significantly more fatigued (t = -2.18, p < .05) and less shy (t = 2.09, p = .05). While not achieving statistical significance, the students were less attentive (t = 1.76, p = .10) and were less surprised (t = .161, p = .13). It is felt that had the number of participants been greater, these effects may have emerged as significant. All other PANAS-X subscales did not achieve statistical significance. Locus of Control results: participation in the study abroad resulted in increases in chance locus of control (t = -2.51, p < .02). The internal and powerful others orientation measures were not significant. Dark Triad findings: the Machiavellian scale (t = 1.83, p < .08) and the Psychopathy measure (t = -1.54, p = .14) approached but did not achieve statistical significance. Again, had a larger sample size been possible, these effects may have reached significance. The Narcissism index was not significantly different. Competitive State Anxiety Inventory results indicated there were no significant changes in somatic anxiety, cognitive anxiety, or self-confidence as a result of the study abroad experience. Conclusion These analyses demonstrated changes in personality characteristics resulting from participation in a study abroad program. Future research may compare study abroad experiences in Europe versus other countries. It would be interesting to study personality characteristics associated with other forms of international travel such as family experiences or internships, etc. Future studies might involve the effect of study abroad experiences upon a more thorough assessment of subjective experiences. A future increase in sample size should increase the power of the statistical analysis.

Pharmacological Analysis of Dopamine Modulation in the \u3cem\u3eDrosophila melanogaster\u3c/em\u3e Larval Heart

Dopamine (DA) and other neurotransmitters affect nonneuronal tissues in insects by circulating in the hemolymph. In several organisms, DA has been shown to modulate distinct aspects of cardiac function but the signal transduction pathways that mediate dopaminergic effects on the heart are not well characterized. Here, we used a semiintact Drosophila melanogaster larva preparation and drugs targeting DA receptors and canonical second messenger pathways to identify signaling cascades that mediate the effect of DA on a myogenic heart. DA has a positive chronotropic effect that is mimicked by SKF38393 (type‐1 DA receptor agonist) and quinpirole (type‐2 DA receptor agonist). SCH23390 and spiperone (type‐1 and type‐2 DA receptor antagonists) are moderately effective at inhibiting DA\u27s effect. An adenylate cyclase inhibitor (SQ,22536) is also effective at blocking the stimulatory effect of DA but the drug has its own dose‐dependent effect. Activation of protein kinase C with a diacylglycerol analog has a stimulatory effect on heart rate (HR). These results suggest that (1) both DA receptor subtypes are expressed in third instar larva cardiac myocytes to increase HR in response to rising levels of DA in the hemolymph, and (2) canonical second messenger pathways modulate HR in D. melanogaster larvae. Having these disparate signaling cascades converge toward a common modulatory function appears redundant, but in the context of multiple cardioactive chemicals this redundancy is likely to increase the fidelity of signal transduction

The impacts of host association and perturbation on symbiont fitness

Symbiosis can benefit hosts in numerous ways, but less is known about whether interactions with hosts benefit symbionts—the smaller species in the relationship. To determine the fitness impact of host association on symbionts in likely mutualisms, we conducted a meta-analysis across 91 unique host-symbiont pairings under a range of spatial and temporal contexts. Specifically, we assess the consequences to symbiont fitness when in and out of symbiosis, as well as when the symbiosis is under suboptimal or varying environments and biological conditions (e.g., host age). We find that some intracellular symbionts associated with protists tend to have greater fitness when the symbiosis is under stressful conditions. Symbionts of plants and animals did not exhibit this trend, suggesting that symbionts of multicellular hosts are more robust to perturbations. Symbiont fitness also generally increased with host age. Lastly, we show that symbionts able to proliferate in- and outside host cells exhibit greater fitness than those found exclusively inside or outside cells. The ability to grow in multiple locations may thus help symbionts thrive. We discuss these fitness patterns in light of host-driven factors, whereby hosts exert influence over symbionts to suit their own needs

Host genotype and genetic diversity shape the evolution of a novel bacterial infection

Pathogens continue to emerge from increased contact with novel host species. Whilst these hosts can represent distinct environments for pathogens, the impacts of host genetic background on how a pathogen evolves post-emergence are unclear. In a novel interaction, we experimentally evolved a pathogen (Staphylococcus aureus) in populations of wild nematodes (Caenorhabditis elegans) to test whether host genotype and genetic diversity affect pathogen evolution. After ten rounds of selection, we found that pathogen virulence evolved to vary across host genotypes, with differences in host metal ion acquisition detected as a possible driver of increased host exploitation. Diverse host populations selected for the highest levels of pathogen virulence, but infectivity was constrained, unlike in host monocultures. We hypothesise that population heterogeneity might pool together individuals that contribute disproportionately to the spread of infection or to enhanced virulence. The genomes of evolved populations were sequenced, and it was revealed that pathogens selected in distantly-related host genotypes diverged more than those in closely-related host genotypes. S. aureus nevertheless maintained a broad host range. Our study provides unique empirical insight into the evolutionary dynamics that could occur in other novel infections of wildlife and humans