Male Cope’s Gray Treefrogs (\u3cem\u3eHyla chrysoscelis\u3c/em\u3e) In Amplexus Have Elevated And Correlated Steroid Hormones Compared To Solitary Males

Gonadal steroid hormones are typically elevated during the breeding season—a finding known as an associated reproductive pattern. Though less studied, there is also evidence, in both sexes, for elevated adrenal/interrenal steroids, including acute elevations on the day of mating. I investigated gonadal and interrenal steroids in wild male Cope’s gray treefrogs at breeding aggregations. I collected blood from males found in amplexus with female mates (amplexed males) and males sampled at the same time and location that were actively advertising vocally and without a mate (solo males). Concentrations of plasma corticosterone, testosterone, and 17β-estradiol (CORT, T and E₂, respectively) were validated and measured. These two categories of males differed in four ways: (1) amplexed males exhibited significantly elevated concentrations of all three steroids compared to solo males (CORT: +347 %; T: +60 %; and E₂: +43 %); (2) these hormone profiles alone accurately predicted male mating category with ca. 83 % accuracy using a discriminant function analysis; (3) amplexed males exhibited significant between-hormone correlations (T and E₂ were positively correlated and CORT and E₂ were negatively correlated) whereas no correlations were found in solo males; (4) amplexed males showed a negative correlation with CORT concentration and the time of night, whereas no such pattern was present in solo males. These findings suggest an acute and strong coactivation of the interrenal and gonadal axes that could drive phenotypic integration during this fitness-determining moment. I discuss these findings and suggest experiments to determine causation, including the role of motor behavior driving endocrine states and the role of female selection on endocrine profiles

Prelude To Molecularization: The Double Gradient Model Of Sulo Toivonen And Lauri Saxén

The present molecular investigations of Organizer phenomena show a remarkable connection to the earlier classical embryological studies that used transplantation as a method for making mechanistic models of induction. One of the most prominent of these connections is the dual gradient model for anterior-posterior and dorsal-ventral polarity. This paper will discuss some of the history of how transplantation experiments provided data that could be interpreted in terms of two gradients of biologically active materials. It will highlight how the attempts to discover the elusive Induktionsstoffen gave rise to the double gradient model of Sulo Toivonen and Lauri Saxén in the 1950s and 1960s. This paper will also document how this research into the identity of these molecules gave rise to the developmental genetics that eventually would find the molecules responsible for primary embryonic induction

Quantitative Separation Of Polystyrene Nanoparticles In Environmental Matrices With Picogram Detection Limits Using Capillary Electrophoresis

We developed a capillary electrophoresis method to separate polystyrene particles (PSPs) with different sizes or different surface functionalities. Separations were performed in buffer and 100 mg L⁻¹ clay or 100 mg L⁻¹ Suwanee River humic acid. In all solutions, PSPs were baseline or near-baseline resolved in less than 15 minutes

Noise And Light Pollution Elicit Endocrine Responses In Urban But Not Forest Frogs

Urban areas are characterised by the presence of sensory pollutants, such as anthropogenic noise and artificial light at night (ALAN). Animals can quickly adapt to novel environmental conditions by adjusting their behaviour, which is proximately regulated by endocrine systems. While endocrine responses to sensory pollution have been widely reported, this has not often been linked to changes in behaviour, hampering the understanding of adaptiveness of endocrine responses. Our aim was, therefore, to investigate the effects of urbanisation, specifically urban noise and light pollution, on hormone levels in male urban and forest túngara frogs (Engystomops pustulosus), a species with reported population divergence in behaviour in response to urbanisation. We quantified testosterone and corticosterone release rates in the field and in the lab before and after exposure to urban noise and/or light. We show that urban and forest frogs differ in their endocrine phenotypes under field as well as lab conditions. Moreover, in urban frogs exposure to urban noise and light led, respectively, to an increase in testosterone and decrease in corticosterone, whereas in forest frogs sensory pollutants did not elicit any endocrine response. Our results show that urbanisation, specifically noise and light pollution, can modulate hormone levels in urban and forest populations differentially. The observed endocrine responses are consistent with the observed behavioural changes in urban frogs, providing a proximate explanation for the presumably adaptive behavioural changes in response to urbanisation

COVID-19 As A Chronic Stressor And The Importance Of Individual Identity: A Data-Driven Look At Academic Productivity During The Pandemic

The COVID-19 pandemic impacted personal and professional life. For academics, research, teaching, and service tasks were upended and we all had to navigate the altered landscape. However, some individuals faced a disproportionate burden, particularly academics with minoritized identities or those who were early career, were caregivers, or had intersecting identities. As comparative endocrinologists, we determine how aspects of individual and species-level variation influence response to, recovery from, and resilience in the face of stressors. Here, we flip that framework and apply an integrative biological lens to the impact of the COVID-19 chronic stressor on our endocrine community. We address how the pandemic altered impact factors of academia (e.g., scholarly products) and relatedly, how factors of impact (e.g., sex, gender, race, career stage, caregiver status, etc.) altered the way in which individuals could respond. We predict the pandemic will have long-term impacts on the population dynamics, composition, and landscape of our academic ecosystem. Impact factors of research, namely journal submissions, were altered by COVID-19, and women authors saw a big dip. We discuss this broadly and then report General and Comparative Endocrinology (GCE) manuscript submission and acceptance status by gender and geographic region from 2019 to 2023. We also summarize how the pandemic impacted individuals with different axes of identity, how academic institutions have responded, compile proposed solutions, and conclude with a discussion on what we can all do to (re)build the academy in an equitable way. At GCE, the first author positions had gender parity, but men outnumbered women at the corresponding author position. Region of manuscript origin mattered for submission and acceptance rates, and women authors from Asia and the Middle East were the most heavily impacted by the pandemic. The number of manuscripts submitted dropped after year 1 of the pandemic and has not yet recovered. Thus, COVID-19 was a chronic stressor for the GCE community

Using \u3cem\u3eCaulobacter crescentus\u3c/em\u3e as a Model to Probe the Environmental Reactivity of Silver Nanoparticles

Silver nanoparticles (AgNPs) are an increasingly common environmental pollutant with antimicrobial and antibacterial properties. The elucidation of their interaction with cellular membranes and subsequent mechanisms of toxicity are critical areas of research that need to be better understood in order to manage potential adverse environmental effects. This work investigates the interaction of AgNPs with large unilamellar vesicles (LUVs) as a model membrane system. Similar studies conducted by others in this field have largely been conducted with uncoated AgNPs, ignoring the effect of environmental conditions on the formation of an eco-corona on AgNPs. Thus, in this study, the spent medium (SM) of a relevant environmental bacterium, Caulobacter crescentus , was used to form a complex eco-corona. We hypothesized that the eco-corona would mediate the in vivo reactivity of AgNPs, specifically through distinct interactions at the cell membrane. The differential reactivity of AgNPs and SM AgNPs is shown through an in vivo toxicity study using C. crescentus. Model membranes were analyzed using dynamic light scattering (DLS), in which AgNP and LUV size and charge are characterized, and fluorescence anisotropy, where changes to LUV membrane fluidity and dynamics are interrogated. Results of the in vivo study are presented in tandem with model membrane studies in order to correlate toxicity effects seen in vivo with potential mechanisms of reactivity at the cell membrane

Review Of A Call To Dissent: Defending Democracy Against Extremism And Populism By S. Sim

The book is an extended polemic urging an attitude and a practice of dissent in politics, religion, science, aesthetics, and even one’s own self-understanding. Sim (critical theory, Northumbria Univ., UK) writes from a general postmodern perspective represented prominently by Derrida and Lyotard, but the book can be read profitably by those with any nondogmatic perspective. Indeed, underlying Sim’s clarion call for dissent is a decidedly liberal view decrying “the loss of personal liberty and human rights” (p. 7). The targets here are a variety of authoritarian regimes, including authoritarian-light regimes in the UK and US. Sim argues for dissent not only in politics but also wherever there are oppressive hegemonic authoritarian regimes. In aesthetics, for example, the agreed on canons for judging artwork tend to make art rule-bound and exclusionary. The author is aware that dissent or skepticism for its own sake is puerile, so dissent must be reasoned. In his discussion of various thinkers, including Hegel, Marx, Hume, and Kant, Sim\u27s criticisms are far too impressionistic, so this is not a book for scholars. However, it encourages greater dissent against oppressive authority and is well worth reading for the general public. Summing Up: Recommended. Undergraduates and general readers

Get Out to Got Out: Residential Mobility and the Language of Opportunity in a Black Southern Louisiana Family

This study examines the migration of Black, middle and upper class members of my family from Black neighborhoods in Southern Louisiana into white neighborhoods. Most of the canon on Black residential patterns question why such high levels of residential segregation remain. Thus, the existing literature explores various structural and individual reasons as to why Black households, regardless of income level, continually reside in Black neighborhoods, even though they often exhibit higher rates of poverty and associated characteristics. This research project approaches the topic from the opposite end, centering its analysis on Black individuals who move into white neighborhoods, in order to introduce a new perspective into the academic discourse. Further, I pull from Marxist frameworks to establish the racial capitalist hierarchy as the foundational structure which informs how our broader systems function and infiltrates to the level of individual decisions. This study analyzes four, in-depth interviews with family members and a close family friend, who discuss their, and in the case of one, their parent’s, migration out of Southern Louisiana. Autoethnographic sections are interwoven throughout as I reflect on my own relation to this topic, which was the grounding inspiration for this inquiry. I supplement these interviews with a historical review of the era in which my participants grew up in, during the prime years of school integration in the 1970s and 1980s. I conclude that this moment in history made highly visible the connections between one’s individual capital and their political and ideological positions through exercises of white flight. This becomes an imperative framework through which the participants of this study view their own practices of residential decision making. Fundamentally, what draws individuals to migrate from Black to white neighborhoods is the quest for opportunity, which signals a trade-off between living amongst one’s community or having access to increased resources. I describe this as the extra, or hidden, costs to Black residential decision making

Navigating the Personal Statement in an Upper-Middle-Class Community

This thesis examines college application choices, conceptions of pressure and ambition, and parenting styles as they affect personal statement success in an upper-middle-class suburb of Massachusetts. I draw on Pierre Bourdieu’s theory of cultural capital and Adrie Kusserow’s theory of soft individualism to analyze five semi-structured interviews with Eastborough, MA parents, students, and a private college counselor. I show that Eastborough parents and students stigmatize peers with overt college ambitions despite enacting ambition themselves. They represent their soft individualism approach as a potential sacrifice for college chances, but it ultimately provides students with two things that college admissions officers value greatly in personal statements: unique achievements and self-knowledge. This thesis sheds light on how cultural capital, as manifested in classed parenting styles, helps to gatekeep elite education and ultimately reproduce class