Allegheny College

ABSTRACT The composition of host-associated microbial communities may correlate with the overall status of the host, including physiology and fitness. New bidirectional hypotheses suggest that sexual behaviors can shape, and be shaped by reproductive microbiomes, which may be particularly important for species with mating systems that feature strong sexual selection. These dynamics have been particularly understudied in female animals. Using 16S rRNA sequencing, we compared the cloacal microbiome of females and males from two socially polyandrous bird species that vary in the strength of sexual selection, Jacana spinosa (Northern Jacana) and J. jacana (Wattled Jacana). We hypothesized that the strength of sexual selection would shape cloacal microbial diversity, such that the more polyandrous J. spinosa would have a more diverse microbiome, and that microbiomes would be more diverse in females than in males. If the reproductive microbiome is indicative of competitive status, we also hypothesized that cloacal microbial diversity would be associated with competitive traits, including plasma testosterone levels, body mass, or weaponry. We found no differences in microbial alpha diversity between species or sexes, but we did find that microbial beta diversity significantly differed between species. We also found a positive relationship between microbial alpha diversity and testosterone in female J. spinosa. Future experiments are needed to explore the potential drivers of correlations between the cloacal microbiome and competitive phenotypes in socially polyandrous jacanas.

Different brain rhythms are often signatures of different behavioral and perceptual states of the brain. As resonance at neurons has a close connection with brain rhythms, characterizing and analyzing the neuronal resonance promote the understanding of brain rhythms and dynamical organization of the brain. In this paper, we study the resonant behaviors of both the four-dimensional (4D) Hodgkin-Huxley model and a reduced-order (2D) model at the subthreshold level. We analyze the frequency responses of a neuron and characterize resonance through investigating the neuron's transfer functions, frequency response functions, and root locus plots. The 2D model, especially, allows us to visualize the state space, perform phase plane analysis, and derive a closed-form formula for the resonant frequency. These analyses will be generalized to study resonance at the spiking regime and network level in future work.

[Voir la version anglaise de l’article ici : www.cmaj.ca/lookup/doi/10.1503/cmaj.241281][1] Le manque de confiance envers les médecins, les institutions et les gouvernements est un problème qui gagne en importance dans le domaine de la santé. La pandémie de COVID-19 a particulièrement

Background and Objective: Reprogramming scar fibroblasts into cardiomyocytes partly reverses the damage associated with myocardial infarction. However, functional improvements are limited due to our limited mechanistic understanding. Our previous studies have highlighted the role of innate immune RNA-sensing receptors in fibroblast-to-cardiomyocyte reprogramming. However, these receptors represent only a part of the broader innate immune response, leaving the full impact of innate immunity on fibroblast-to-cardiomyocyte reprogramming an open question.

Abstract Merging binary black holes (BBHs) formed dynamically in dense star clusters are expected to have uncorrelated spin–orbit orientations since they are assembled through many random interactions. However, measured effective spins in BBHs detected by LIGO/Virgo/KAGRA hint at additional physical processes that may introduce anisotropy. Here we address this question by exploring the impact of stellar collisions and accretion of collision debris on the spin–orbit alignment in merging BBHs formed in dense star clusters. Through hydrodynamic simulations, we study the regime where the disruption of a massive star by a BBH causes the stellar debris to form individual accretion disks bound to each black hole (BH). We show that these disks, which are randomly oriented relative to the binary orbital plane after the initial disruption of the star, can be reoriented by strong tidal torques in the binary near pericenter passages. Following accretion by the BHs on longer timescales, BBHs with small but preferentially positive effective spin parameters (χ eff ≲ 0.2) are formed. Our results indicate that BBH collisions in young massive star clusters could contribute to the observed trend toward small positive χ eff, and we suggest that the standard assumption often made that dynamically assembled BBHs should have isotropically distributed BH spins is not always justified.

A review of A History of African American Autobiography edited by Joycelyn K. Moody.

Abstract In 2014, The Public Religion Research Institute and the American Academy of Religion released a report called Believers, Sympathizers, & Skeptics: Why Americans Are Conflicted About Climate Change, Environmental Policy, and Science, which found that a total of 78% of Jewish Americans considered climate change a “crisis” or a “major problem.” (Jones et al., 2014, p. 12). In this article, I argue that even as Jewish perspectives on climate change and the environment are varied, there are significant resources within the Jewish tradition that contributed to the development and growth of Jewish environmentalism and climate change activism and advocacy.