Biology subjects

Smith, C. T.

Publications and source records attributed to Smith, C. T..

11 recordsLinked to original sources

bioRxiv2026

When are Biomedical Postdocs Ready for the Faculty Job Market? A Mixed-Methods Analysis of Metrics and Resilience Among Faculty Job Seekers

PurposeDiscussions surrounding the biomedical faculty job market often focus on applicant competitiveness and external metrics such as number of publications and funding records. Consequently, there is typically less discussion about applicant readiness, the point at which applicants perceive themselves as prepared to enter the market. Since 2018 our group, the Faculty Job Market Collaboration (FJMC), has conducted annual end-of-cycle surveys of biomedical faculty job applicants, producing the largest longitudinal dataset on this process to date. MethodsWe employed a mixed-methods design examining faculty applicants in biological science fields in North America. Regression analyses were conducted on a longitudinal dataset of 729 respondents across multiple hiring cycles. To determine how applicants evaluated their own preparation, qualitative interviews were conducted with a separate cohort of biomedical postdoctoral applicants during the 2024-2026 job cycles. ResultsOur findings demonstrate that rather than depending on a single quantitative threshold, readiness is a multifaceted construct shaped by actionable and interpersonal drivers. Key factors influencing an applicants perceived readiness include taking agency to submit applications, receiving explicit support from a mentor, incorporating strategic use of artificial intelligence tools into application preparation, and their career stage. ConclusionBy distinguishing individual readiness from systemic assumptions of market competitiveness, this study highlights a blind spot in academic workforce development. Our results suggest that applicants can achieve readiness and successful outcomes through different combinations of support, strategy, and timing rather than a uniform metric profile. By integrating quantitative and qualitative data, our study provides an evidence-based framework for understanding applicant readiness and offers practical guidance to help trainees navigate the increasingly competitive academic job market. Teaser TextOur mixed-model analysis of the biomedical faculty job market is designed to help prospective faculty candidates assess their readiness to enter the job market. By integrating multiple indicators of academic productivity, funding success, and professional experience, our study provides evidence-based benchmarks that can guide applicants in evaluating their competitiveness and identifying areas for further development before pursuing faculty positions.

scientific communication and education↗

bioRxiv2026

No adaptive plasticity in the heat tolerance of lizard sperm

O_LIAdaptive phenotypic plasticity can help organisms cope with global warming by increasing their heat tolerance, yet most research has focused on whole-organism traits. Much less is known about thermal plasticity at the gamete level despite increasing evidence that reproduction, and particularly sperm function, is especially sensitive to heat. C_LIO_LIWe tested for plasticity in sperm heat tolerance in two ways: via male thermal acclimation (pre-ejaculate stage) and via sperm cell heat hardening (post-ejaculate stage) in brown anole lizards (Anolis sagrei). We also measured plasticity in several other sperm and ejaculate traits in response to male thermal acclimation. C_LIO_LITo test for effects of male thermal acclimation, adult males were exposed to one of two ecologically realistic, fluctuating temperature regimes that either mimic cool spring conditions or projected future summer conditions for eight weeks. Throughout this period, we repeatedly measured sperm heat tolerance (LT50), baseline motility, and sperm count. We also measured sperm morphology at the end of thermal acclimation. We predicted that males in the warmer treatment would produce more heat tolerant sperm. C_LIO_LITo test for post-ejaculate heat hardening, we compared the heat tolerance of ejaculated sperm that either did or did not experience a high but non-lethal temperature prior to heat tolerance measurement. C_LIO_LIWe found no plasticity in sperm heat tolerance due to either male thermal acclimation or sperm cell heat shock. Long-term thermal acclimation of males did not increase sperm heat tolerance, nor change motility, sperm count, or sperm morphology. We also found no evidence for post-ejaculate heat hardening, as exposing sperm cells to mild sublethal heat shock did not enhance sperm heat tolerance. C_LIO_LIOur results indicate that gametic traits have limited capacity for plastic adjustment to thermal stress, which is broadly consistent with the low levels of thermal plasticity found for whole-organism thermal tolerance across ectotherms. This highlights the vulnerability of reproductive traits to rising temperatures and the importance of evolutionary and behavioral responses to buffer organisms from climate change. C_LI

ecology↗

bioRxiv2024

APOE4 alters the lipid droplet proteome and modulates droplet dynamics

Excess lipid droplet (LD) accumulation is associated with several pathological states, including Alzheimers disease (AD). However, the mechanism(s) by which changes in LD composition and dynamics contribute to pathophysiology of these disorders remains unclear. Apolipoprotein E (ApoE) is a droplet associated protein with a common risk variant (E4) that confers the largest increase in genetic risk for late-onset AD. E4 is associated with both increased neuroinflammation and excess LD accumulation. In the current study, we sought to quantitatively profile the lipid and protein composition of LDs between the neutral E3 and risk variant E4, to gain insight into potential LD-driven contributions to AD pathogenesis. Targeted replacement mice expressing human E3 or E4 were injected with saline or lipopolysaccharide (LPS), and after 24 hours, hepatic lipid droplets were isolated for proteomic and lipidomic analyses. Lipidomics revealed a shift in the distribution of glycerophospholipids in E4 LDs with a concomitant increase in phosphatidylcholine species, and overall, the baseline profile of E4 LDs resembled that of the LPS-treated groups. Quantitative proteomics showed that LDs from E4 mice are enriched for proteins involved in protein/vesicle transport but have decreased levels of proteins involved in fatty acid {beta}-oxidation. Interestingly, proteins associated with LDs showed substantial overlap with previously published lists of AD postmortem tissue and microglia omics studies, suggesting a potential role for LDs in modulating AD risk or progression. Given this, we exposed primary microglia from the same E3 or E4 mice to exogenous lipid, inflammatory stimulation, necroptotic N2A cells (nN2A), or a combination of treatments to evaluate LD formation and its impact on the cells immune state. Microglia from E4 mice accumulated more LDs in every condition tested - at baseline and following addition of fatty acids, LPS stimulation, or nN2As. E4 microglia also secreted significantly more cytokines (TNF, IL-1{beta}, IL-10) than E3 microglia in the control, oleic acid, and nN2A treatment conditions, yet showed a blunted response to LPS. In sum, these results suggest that E4 microglia accumulate more LDs compared to E3 microglia and that E4 is associated with a basal LD composition that resembles a pro-inflammatory cell. Together with the high overlap of the LD proteome with established AD-associated datasets, these data further support the idea that alterations in LD dynamics, particularly within microglia, may contribute to the increased risk for AD associated with APOE4.

physiology↗

bioRxiv2023

Insights from a survey of mentorship experiences by graduate and postdoctoral researchers

Mentorship is vital for early career researchers in training positions, allowing them to navigate the challenges of work and life in research environments. However, the quality of mentorship received by trainees can vary by investigator and by institution. One challenge faced by those hoping to improve trainee mentorship is that the extent to which mentorship is offered to and experienced by research trainees is not well characterized. To address this knowledge gap, we conducted a survey to examine the quality of mentorship received by trainees in research environments, to identify characteristics of positive and negative mentorship, and to highlight best practices to improve trainee mentorship. We received 2,114 responses from researchers at graduate and postdoctoral career stages worldwide. Quantitative analysis showed that at least [~]25-45% of respondents were dissatisfied with some aspects of their mentorship. Qualitative responses revealed that common issues in mentorship include unclear expectations in research and mentoring interactions, lack of guidance, and inadequate support of trainee independence and career goals. Our findings also identified key mentorship elements desired by trainee mentees. Based on trainee suggestions, we describe strategies for individual mentors, departments, and institutions to improve the training experience for graduate and postdoctoral researchers.

scientific communication and education↗

bioRxiv2022

The faculty-to-faculty mentorship experience: a survey on challenges and recommendations for improvements

Faculty at research institutions play a central role in advancing knowledge and careers, as well as promoting the well-being of students and colleagues in research environments. Faculty members must balance a host of activities - such as performing research, teaching, sourcing funds, administrative and service duties - with their roles as educators and mentors. Mentorship from experienced peers has been touted as critical for enabling these myriad roles to allow faculty development, career progression, and satisfaction. However, there is little information available on who supports faculty and best ways to structure a faculty mentorship program for early- and mid-career academics. Furthermore, the extent to which mentorship and mentoring programs have been offered to faculty members has not been widely characterized. It is also unclear what challenges faculty receiving mentorship may face and which aspects could be further improved. In the interest of advocating for increased and enhanced faculty mentoring and mentoring programs, we surveyed faculty (i.e., group leaders) around the world to gather data on whether and how they receive mentoring from peers, senior researchers, informal mentoring programs, or formal mentoring programs at their institutions. We received responses from 457 early- and mid-career faculty and found that a substantial portion of respondents either reported having no mentor or a lack of a formal mentoring scheme. Qualitative responses on the quality of mentorship revealed that the most common complaints regarding mentorship included lack of mentor availability, unsatisfactory commitment to mentorship, and non-specific or non-actionable advice. Our findings further identified key mentorship elements desired by faculty mentees. Based on these suggestions, we identify a need for training for faculty mentors as well as strategies for individual mentors, departments, and institutions for funding and design of more intentional and supportive mentorship programs for early- and mid-career faculty.

scientific communication and education↗

bioRxiv2022

The U.S. academic job market survives the SARS-CoV-2 global pandemic

PurposeThis paper aims to identify the extent to which the COVID-19 pandemic disrupted the academic job market and the ways in which faculty job applicants altered their applications in response to a changing academia. Design/methodology/approachThe data presented here is the portion relevant to COVID-19 collected in a survey of faculty job applicants at the end of the 2019-2020 job cycle in North America (spring 2020). An additional "mid-pandemic" survey was used in fall 2020 for applicants participating in the following job search cycle to inquire about how they were adapting their application materials. A portion of data from the 2020-2022 job cycle surveys was used to represent the "late-pandemic". Job posting data from the Higher Education Recruitment Consortium (HERC) is also used to study job availability. FindingsExamination of faculty job postings from 2018 through 2022 found that while they decreased in 2020, the market recovered in 2021 and beyond. While the market recovered, approximately 10% of the faculty job offers reported by 2019-20 survey respondents were rescinded. Respondents also reported altering their application documents in response to the pandemic as well as delaying or even abandoning their faculty job search. OriginalityThis paper provides a longitudinal perspective with quantitative data on how the academic job market changed through the major events of the COVID-19 pandemic in North America, a subject of intense discussion and stress, particularly amongst early career researchers.

scientific communication and education↗

bioRxiv2022

APOE modulates microglial immunometabolism in response to age, amyloid pathology, and inflammatory challenge

The E4 allele of Apolipoprotein E (APOE) is associated with both metabolic dysfunction and a heightened pro-inflammatory response - two findings that may be intrinsically linked through the concept of immunometabolism. Here, we combined bulk, single-cell, and spatial transcriptomics with cell-specific and spatially resolved metabolic analyses to systematically address the role of APOE across age, neuroinflammation, and AD pathology. RNAseq highlighted immunometabolic changes across the APOE4 glial transcriptome, specifically in subsets of metabolically distinct microglia enriched in the E4 brain during aging or following an inflammatory challenge. E4 microglia display increased Hif1 expression, a disrupted TCA cycle, and are inherently pro-glycolytic, while spatial transcriptomics and MALDI mass spectrometry imaging highlight an E4-specific response to amyloid that is characterized by widespread alterations in lipid metabolism. Taken together, our findings emphasize a central role for APOE in regulating microglial immunometabolism.

neuroscience↗

bioRxiv2021

Dopamine biases sensitivity to personal goals and social influence in self-control over everyday desires

People regularly give in to daily temptations in spite of conflict with personal goals. To test hypotheses about neuropharmacological influences on self-control, we used positron emission tomography to measure dopamine D2-like receptors (D2R) and experience sampling surveys to naturalistically track daily desires outside the laboratory in everyday life in a sample of 103 adults. Higher D2R availability in the ventral striatum was associated with increased sensitivity to personal goal conflict but not desire strength in deciding whether to attempt to resist a desire. The influence of D2Rs on sensitivity to personal goal conflict depended on whether desires were experienced in a social context. D2R availability in the midbrain (but not the ventral striatum) influenced whether desires were enacted. These findings provide unique evidence that the dopamine system influences decision making and regulatory behavior and provides new insights into how these mechanisms interact with personal goals and social contexts.

neuroscience↗

bioRxiv2019

Insights from a survey-based analysis of the academic job market

Applying for a faculty position is a critical phase of many postdoctoral careers, but most postdoctoral researchers in STEM fields enter the academic job market with little knowledge of the process and expectations. A lack of data has made it difficult for applicants to assess their qualifications relative to the general applicant pool and for institutions to develop effective hiring policies. We analyzed responses to a survey of faculty job applicants between May 2018 and May 2019. We establish various background scholarly metrics for a typical faculty applicant and present an analysis of the interplay between those metrics and hiring outcomes. Traditional benchmarks of a positive research track record above a certain threshold of qualifications were unable to completely differentiate applicants with and without offers. Our findings suggest that there is no single clear path to a faculty job offer and that metrics such as career transition awards and publications in high impact factor journals were neither necessary nor sufficient for landing a faculty position. The applicants perceived the process as unnecessarily stressful, time-consuming, and largely lacking in feedback, irrespective of a successful outcome. Our findings emphasize the need to improve the transparency of the faculty job application process. In addition, we hope these and future data will help empower trainees to enter the academic job market with clearer expectations and improved confidence.

scientific communication and education↗

bioRxiv2018

Reliability of the correlative triad among aging, dopamine D2-like receptor availability, and cognition

The evidence that dopamine function mediates the association between aging and cognition is one of the most cited findings in the cognitive neuroscience of aging. However, few and relatively small studies have directly examined these associations. Here we examined correlations among adult age, dopamine D2-like receptor (D2R) availability, and cognition in two cross-sectional studies of healthy human adults. Participants completed a short cognitive test battery and, on a separate day, a PET scan with either the high-affinity D2R tracer [18F]Fallypride (Study 1) or [11C]FLB457 (Study 2). Digit span, a measure of short-term memory maintenance and working memory, was the only cognitive test for which dopamine D2R availability partially mediated the age effect on cognition. In Study 1, age was negatively correlated with digit span. Striatal D2R availability was positively correlated with digit span controlling for age. The age effect on digit span was smaller when controlling for striatal D2R availability. Although other cognitive measures used here have individually been associated with age and D2R availability in prior studies, we found no consistent evidence for significant associations between low D2R availability and low cognitive performance on these measures. These results at best only partially supported the correlative triad of age, dopamine D2R availability, and cognition. While a wealth of other research in human and non-human animals demonstrates that dopamine makes critical contributions to cognition, the present studies suggest caution in interpreting PET findings as evidence that dopamine D2R loss is a primary cause of broad age-related declines in fluid cognition.

neuroscience↗

bioRxiv2018

Individual differences in dopamine are associated with reward discounting in clinical groups but not in healthy adults

Some people are more willing to make immediate, risky, or costly reward-focused choices than others, which has been hypothesized to be associated with individual differences in dopamine (DA) function. In two studies using PET imaging, one empirical (Study 1: N=144 males and females across 3 samples) and one meta-analytic (Study 2: N=307 across 12 samples), we sought to characterize associations between individual differences in DA and time, probability, and physical effort discounting in human adults. Study 1 demonstrated that individual differences in DA D2-like receptors were not associated with time or probability discounting of monetary rewards in healthy humans, and associations with physical effort discounting were inconsistent across adults of different ages. Meta-analytic results for temporal discounting corroborated our empirical finding for minimal effect of DA measures on discounting in healthy individuals, but suggested that associations between individual differences in DA and reward discounting depend on clinical features. Addictions were characterized by negative correlations between DA and discounting but other clinical conditions like Parkinsons Disease, obesity, and ADHD were characterized by positive correlations between DA and discounting. Together the results suggest that trait differences in discounting in healthy adults do not appear to be strongly associated with individual differences in D2-like receptors. The difference in meta-analytic correlation effects between healthy controls and individuals with psychopathology suggests that individual difference findings related to DA and reward discounting in clinical samples may not be reliably generalized to healthy controls, and vice-versa.\n\nSignificance StatementDecisions to forgo large rewards for smaller ones due to increasing time delays, uncertainty, or physical effort have been linked to differences in dopamine (DA) function, which is disrupted in some forms of psychopathology. It remains unclear whether alterations in DA function associated with psychopathology also extend to explaining associations between DA function and decision making in healthy individuals. We show that individual differences in dopamine D2 receptor availability are not consistently related to monetary discounting of time, probability, or physical effort in healthy individuals across a broad age range. By contrast, we suggest that psychopathology accounts for observed inconsistencies in the relationship between measures of dopamine function and reward discounting behavior.

neuroscience↗