Biology subjects

Jadavji, N. M.

Publications and source records attributed to Jadavji, N. M..

18 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↗

bioRxiv2025

Vascular dementia increases levels of methylenetetrahydro-folate reductase and cystathionine β-synthase in female patients and changes gene expression of acetylcholine and glutamate clathrin-sculpted transport vesicles

Vascular dementia (VaD) is a complex clinical syndrome arising from cerebrovascular disease, characterized by cognitive decline and functional impairment, and is projected to double in prevalence over the next three decades. Deficiencies in one-carbon (1C) metabolism are linked to the onset of VaD. Our previous work using mouse models has demonstrated that reduced dietary folic acid intake or genetic disruptions in 1C metabolism exacerbate outcomes in a model of VaD. However, the impact of VaD on one-carbon metabolism remains poorly understood. This study aims to provide a detailed molecular portrait of 1C metabolism within the context of VaD, shedding light on potential molecular mechanisms. In post-mortem medial prefrontal cortex tissue from VaD female and male patients and controls we measured protein expression of the folate receptor (FR) and 1C enzymes including methylenetetrahydrofolate reductase (MTHFR), thymidylate synthase (TS), choline acetyltransferase (ChAT), acetylcholinesterase (AChE), cystathionine {beta}-synthase (CBS) co-localized with NeuN. There was an interaction between VaD and gender for levels of FR. Both male and female VaD had increased levels of ChAT. Female VaD patients had higher levels of MTHFR and CBS when compared to males. VaD is a complex disease; the results of this study demonstrate that VaD impacts neuronal levels of 1C enzymes. Future studies should assess 1C in other cell types of the brain, as well as measure enzyme activity levels.

neuroscience↗

bioRxiv2025

Ischemic stroke increases levels of the folate receptor and one-carbon enzymes in male and female brain tissue

Stroke is the second most common cause of death worldwide and predominantly affects individuals over 65 years old. Its prevalence is projected to increase in parallel with the aging global population. Nutrition is a modifiable risk factor for ischemic stroke. Folates, B-vitamins and choline play a central role in one-carbon metabolism (1C), which is a key metabolic network that integrates nutritional signals with biosynthesis, redox homeostasis, epigenetics, regulation of cell proliferation, and stress resistance. Our research group has previously shown that deficiencies in 1C lead to worsened stroke outcomes using preclinical models. However, the impact of ischemic stroke on 1C enzymes in affected brain tissue remains unknown. The objective of this study is to investigate whether ischemic stroke contributes to a change in the levels of 1C enzymes after ischemic stroke in male and female patients. Cortical brain tissue sections from ischemic stroke patients and controls were stained for enzymes involved in 1C. All tissue was co-stained with neuronal nuclei (NeuN) and DAPI (4',6-diamidino-2-phenylindole). The colocalization of all three markers was evaluated by two individuals who were blinded to the experimental groups. Ischemic stroke increased neuronal levels of the folate receptor and 1C enzymes, methylenetetrahydrofolate reductase (MTHFR), thymidylate synthase (TS) and serine hydroxy methyltransferase (SHMT). In male stroke brain tissue was observed to have increased levels of MTHFR, TS, and SHMT. Female brain tissue had increases in the folate receptor and TS. The results suggest that ischemic stroke leads to increased demand of 1C and that there are some differences between males and females. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=92 SRC="FIGDIR/small/673861v1_ufig1.gif" ALT="Figure 1"> View larger version (12K): org.highwire.dtl.DTLVardef@18e7c60org.highwire.dtl.DTLVardef@187a339org.highwire.dtl.DTLVardef@1ed0568org.highwire.dtl.DTLVardef@1fdfe31_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

bioRxiv2024

Over supplementation of folic acid reduces survival 24 hours after hypoxia in male and female Drosophila melanogaster

Hypoxia is a major component of ischemic stroke. The prevalence of ischemic stroke is expected to increase as the global population ages and risk factors, like obesity, are on the rise. Nutrition is a modifiable risk factor for ischemic stroke. Increased dietary intake of folic acid (FA) has become an increasing problem in the U.S and other countries as more people are consuming at or above the recommended daily amount of FA. The impact of too much dietary FA on hypoxia is not well understood. This study aimed to investigate how increased dietary levels of FA impact hypoxia outcomes using Drosophila melanogaster as a model. Adult female and male w1118 Drosophila melanogaster flies were placed on control (CD) and 100 {micro}M folic acid (FAD) diets. At 5 to 6 days old fruit fly progeny were exposed to hypoxia for two hours prior to returning to normoxic conditions. We observed escape behavior in hypoxia larvae, confirming exposure to hypoxia. Using liquid chromatography-tandem mass spectrometry, elevated FA levels were observed in FAD compared to controls. We report increased acute hypoxia-induced mortality in FAD flies. Furthermore, FAD flies were not motivated to climb after hypoxia. Under normoxic conditions FAD flies had a higher velocity when descending during a climb. Interestingly, there was no impact of FA on apoptosis in brain tissue post-hypoxia. Together these data suggest that increase dietary intake of FA can have negative health outcomes after hypoxia. HighlightsO_LIHigh dietary folic acid and hypoxia increased mortality at the 24-hour time point. C_LIO_LIHypoxia and folic acid decreased motivation to climb and reduced movement in flies. C_LIO_LINo effect of hypoxia and folic acid on apoptosis levels in the fly brain tissue. C_LI

neuroscience↗

bioRxiv2024

Apoptosis is increased in cortical neurons of female Marfan Syndrome mice

Marfan Syndrome (MFS) is an autosomal dominant genetic disorder that affects connective tissue throughout the body due to mutations in the FBN1 gene. Individuals with MFS display symptoms in different organs, particularly in the vasculature, but the mechanisms of this multi-system dysfunction are still under investigation. There is still a gap in our understanding of the impact of monogenic connective tissue aberrations on the brain. This study aims to determine the impact of MFS on neurodegeneration, in cortical brain tissue of male and female MFS mice. Brain tissue of 6-month-old female and male mice with the FBN1C1041G/+ mutation and wildtype litter mates was collected and stained for active caspase-3 (ac3), brain derived neurotrophic factor (BDNF), and neuronal nuclei (NeuN) or with TUNEL and DAPI. Data revealed increased levels of ac3 in neurons within the sensory and motor cortical areas of female MFS mice compared to sex- and age-matched controls. We confirm increased levels of apoptosis in MFS mice using TUNEL staining within the same brain areas. We also report increased levels of neuronal BDNF levels in cortical brain tissue of male and female MFS mice. These results indicate a heightened susceptibility for neurodegeneration in the mouse model of MFS. Significance StatementThe study revealed that female mice with a FBN1C1041G/+ mutation have more apoptotic neurons in sensory and motor cortical brain tissue compared to wildtype litter mates.

neuroscience↗

bioRxiv2024

An updated and expanded characterization of the biological sciences academic job market

In the biological sciences, many areas of uncertainty exist regarding the factors that contribute to success within the faculty job market. Earlier work from our group reported that beyond certain thresholds, academic and career metrics like the number of publications, fellowships or career transition awards, and years of experience did not separate applicants who received job offers from those who did not. Questions still exist regarding how academic and professional achievements influence job offers and if candidate demographics differentially influence outcomes. To continue addressing these gaps, we initiated surveys collecting data from faculty applicants in the biological sciences field for three hiring cycles in North America (Fall 2019 to the end of May 2022), a total of 449 respondents were included in our analysis. These responses highlight the interplay between various scholarly metrics, extensive demographic information, and hiring outcomes, and for the first time, allowed us to look at persons historically excluded due to ethnicity or race (PEER) status in the context of the faculty job market. Between 2019 and 2022, we found that the number of applications submitted, position seniority, and identifying as a women or transgender were positively correlated with a faculty job offer. Applicant age, residence, first generation status, and number of postdocs, however, were negatively correlated with receiving a faculty job offer. Our data are consistent with other surveys that also highlight the influence of achievements and other factors in hiring processes. Providing baseline comparative data for job seekers can support their informed decision-making in the market and is a first step towards demystifying the faculty job market.

scientific communication and education↗

bioRxiv2024

Maternal dietary deficiency in choline reduced levels of MMP-2 levels in blood and brain tissue of male offspring mice

Ischemic stroke is one of the leading causes of disability and death globally, with a rising incidence in younger age groups. Its well known that maternal diet during pregnancy and lactation is vital for the early neurodevelopment of offspring. One-carbon (1C) metabolism, including folic acid and choline, plays a vital role in closure of the neural tube in utero. However, the impact of maternal dietary deficiencies in 1C on offspring neurological function following ischemic stroke later in life remains undefined. The aim of this study was to investigate inflammation in blood and brain tissue of offspring from mothers deficient in dietary folic acid or choline. Female mice were maintained on either a control or deficient diets prior to and during pregnancy and lactation. When offspring were 3-months of age, ischemic stroke was induced. One and half months later blood and brain tissue were collected. We measured levels of matrix-metalloproteases (MMP)-2 and 9 in both plasma and brain tissue, and report reduced levels of MMP-2 in both, with no changes observed in MMP-9. This observation supports our working hypothesis that maternal dietary deficiencies in folic acid or choline during early neurodevelopment impact the levels of inflammation in offspring after ischemic stroke.

neuroscience↗

bioRxiv2024

Maternal dietary deficiencies in folic acid and choline change metabolites levels in offspring after ischemic stroke

Ischemic stroke is a debilitating disease, with nutrition being a modifiable risk factor. Changes in levels of metabolites can be used to measure the alterations in the gut, a significant marker for the etiology of diseases. This study utilized untargeted metabolomics to investigate changes in fecal samples of offspring in response to maternal dietary deficiencies and ischemic stroke. Female mice were placed on control (CD), folic acid- (FADD), or choline-deficient (ChDD) diets prior to, during pregnancy, and lactation. Offspring were weaned on to CD and at 2 months of age an ischemic stroke was induced. Fecal samples were collected prior to ischemic stroke, and at 1- and 4-weeks post-stroke for analysis. Sex and maternal dietary differences in metabolites were observed at both the 1- and 4-week post-stroke timepoints. At the 1-week post-stroke, female FADD offspring had more changes in metabolites than males. Comparatively, at the 4-week post-stroke timepoint, female offspring on either FADD or ChDD demonstrated metabolite changes. This study demonstrates a long-lasting impact of maternal dietary deficiencies on central nervous system and gut microbiome function after ischemic stroke. Summary StatementOur study investigated metabolite changes in female and male offspring fecal samples from mothers maintained on folic acid or choline deficient diet. We report that female offspring metabolite levels were impacted.

neuroscience↗

bioRxiv2023

Maternal dietary deficiencies in folic acid or choline reduce primary neuron viability after exposure to hypoxia through increased levels of apoptosis

Stoke is the leading cause of death and disability globally. By addressing modifiable risk factors, particularly nutrition, the prevalence of stroke and its dire consequences can be mitigated. One-carbon (1C) metabolism is a critical biosynthetic process that is involved in neural tube closure, neuronal plasticity, and cellular proliferation in the developing embryo. Folic acid and choline are two active components of 1C metabolism, we have previously demonstrated that maternal dietary deficiencies in folic acid or choline worsen stroke outcomes in offspring. However, there is insufficient data to understand the neuronal mechanisms involved. We exposed embryonic neurons of offspring, whom mothers were on folic acid or choline deficient diets, to hypoxia conditions for 6 hours and return to normoxic conditions for 24 hours to model an ischemic stroke and reperfusion injury. To determine whether increased levels of either folic acid or choline can rescue reduced neuronal viability, we supplemented cell media with folic acid and choline prior to and after exposure to hypoxia. Our results suggest that maternal dietary deficiencies in either folic acid or choline during pregnancy negatively impacts offspring neuronal viability after hypoxia. Furthermore, increasing levels of folic acid or choline prior to and after hypoxia have a beneficial impact on neuronal viability. The findings contribute to our understanding of the intricate interplay between maternal dietary factors, 1C metabolism, and the outcome of offspring to hypoxic events, emphasizing the potential for nutritional interventions in mitigating adverse outcomes.

neuroscience↗

bioRxiv2023

Maternal dietary deficiencies in one-carbon metabolism during early neurodevelopment result in larger damage volume, re-duced neurodegeneration and neuroinflammation and changes in choline metabolites after ischemic stroke in middle-aged offspring

Maternal diet pregnancy and lactation is vital to the early life neuro programming of offspring. One-carbon (1C) metabolism, which includes folic acid and choline, plays a vital role in closure of the neural tube and other neurodevelopment. However, the impact of maternal dietary deficiencies on offspring neurological function following ischemic stroke later in life remains undefined. Stroke is one of the leading causes of death globally, and its prevalence is expected to increase in younger age groups as the incidence of various risk factors for stroke increases. Furthermore, our group has shown that dietary deficiencies in 1C metabolism result in worse stroke outcome. Our study aimed to investigate the role of maternal dietary deficiencies in folic acid and choline on ischemic stroke outcome in middle-aged male and female mice. Female mice were maintained on either a control or deficient diets prior to and during pregnancy and lactation. When female and male offspring were 10-months of age, ischemic stroke was induced via photothrombosis targeting the sensorimotor cortex. Stroke outcome was assessed by measuring motor function in living animals and ischemic damage volume, neurodegeneration, neuroinflammation, and choline metabolism in the brain postmortem. No significant difference was observed between maternal dietary groups in offspring motor function; however, males and females differed in their motor function. Maternal diet significantly impacted ischemic damage volume. Male and female offspring from deficient mothers showed significantly reduced neurodegeneration and neuroinflammation within the ischemic damage region. We also report changes in plasma 1C metabolites as a result of maternal diet and sex after ischemic stroke in offspring. Our data indicates that maternal dietary deficiencies do not impact offspring motor outcome following ischemic stroke, but do play a role in other ischemic stroke outcomes such as ischemic damage volume and plasma 1C metabolites in middle-aged adult offspring. Furthermore, our data indicates that sex of mice plays an important role in stroke outcome during middle-age.

neuroscience↗

bioRxiv2022

Maternal dietary deficiencies in folates or choline during pregnancy and lactation worsen stroke outcome in 3-month-old male and female mouse offspring

Maternal one-carbon (1C) metabolism plays an important role in early life programming. There is a well-established connection between the fetal environment and the health status of the offspring. However, there is a knowledge gap on how maternal nutrition impacts stroke outcome in offspring. The aim of our study was to investigate the role of maternal dietary deficiencies in folic acid or choline on stroke outcome in 3-month-old offspring. Adult female mice were fed a folic acid deficient diet (FADD), choline deficient diet (ChDD), or control diet (CD) prior to pregnancy. They were continued on diets during pregnancy and lactation. Male and female offspring were weaned onto a CD and at 2 months of age were subject to ischemic stroke within the sensorimotor cortex via photothrombosis damage. At 3-months-of-age, motor function was measured in offspring and tissue was collected for analysis. Mothers maintained on either a FADD or ChDD had reduced levels of S-adenosylmethionine in liver and S-adenosylhomocysteine in plasma. After ischemic stroke, motor function was impaired in 3-month-old offspring from deficient mothers compared to CD animals. In brain tissue, there was no difference in ischemic damage volume. When protein levels were assessed in brain tissue, there were lower levels of neurodegeneration in males compared to females and betaine levels were reduced in offspring from ChDD mothers. Our results demonstrate that a deficient maternal diet during critical timepoints in neurodevelopment results in worse stroke outcomes. This study emphasizes the importance of maternal diet and the impact it can have on offspring health.

neuroscience↗

bioRxiv2022

Maternal dietary choline deficiencies during pregnancy and lactation reduce cerebral blood flow in 3-month-old female mice offspring following ischemic stroke to the sensorimotor cortex

Background and PurposeAdequate maternal dietary levels of one-carbon (1C) metabolites, such as folic acid and choline, play an important role in the closure of the neural tube in utero; however, the impact of deficiencies in 1C on offspring neurological function after birth remain undefined. Stroke is one of the leading causes of death and disability globally. The aim of our study was to determine the impact of maternal 1C nutritional deficiencies on cerebral and peripheral blood flow after ischemic stroke in adult female offspring. MethodIn this study, female mice were placed on either control (CD), folic acid (FADD), or choline (ChDD) deficient diets prior to pregnancy. Female offspring were weaned onto a CD for the duration of the study. Ischemic stroke was induced in offspring and after six weeks cerebral and peripheral blood flow velocity was measured using ultrasound imaging. ResultsOur data showed that 11.5-month-old female offspring from ChDD mothers had reduced blood flow in the posterior cerebral artery compared to controls. In peripheral blood flow velocity measurements, we report an aging effect. ConclusionsThese results emphasize the importance of maternal 1C diet in early life neuro-programming on long-term vasculature health.

neuroscience↗

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

Reduced stroke outcome in old-aged female mice maintained on a dietary vitamin B12 deficiency

The global population is aging and the prevalence of age-related diseases, such as stroke, is predicted to increase. A vitamin B12 deficiency (vit. B12 def.) is common in the elderly, because of changes in metabolism. Clinical studies have reported that a vit. B12 def results in worse outcome after stroke, the mechanisms through which a vit. B12 def. changes the brain requires further investigation. This study investigated the role of vit. B12 def. on stroke outcome and mechanisms using aged female mice. Eighteen month old females were put on a control or vit. B12 def. diet for four weeks, after which an ischemic stroke was induced in the sensorimotor cortex. After damage, motor function was measured and animals were euthanized and tissues were collected for analysis. Vit. B12 def. animals had increased levels of total homocysteine in plasma and liver, choline levels were also increased in the liver. Vit. B12 def. animals had larger damage volume in brain tissue and more apoptosis. In the cecum, changes in creatinine and methylmalonic acid were observed in vit. B12 def. animals, pathway analysis showed dysfunction in B12 transport. Analysis of mitochondrial metabolomics in brain tissue showed reduced levels of metabolites involved in the TCA cycle in vit. B12 def animals. Meanwhile, pathway analysis showed significant, widespread dysfunction in phenylalanine, tyrosine, and tryptophan biosynthesis. Motor function after stroke was impaired in vit. B12 def. animals. A dietary vitamin B12 deficiency impairs motor function through increased apoptosis and changes in mitochondrial metabolism in brain tissue.

physiology↗

bioRxiv2021

A dietary vitamin B12 deficiency impairs motor function and changes neuronal survival and choline metabolism after ischemic stroke to the sensorimotor cortex in middle aged male and female mice

Nutrition is a modifiable risk factor for ischemic stroke. As people age their ability to absorb some nutrients decreases, a primary example is vitamin B12. Older individuals with a vitamin B12 deficiency are at a higher risk for ischemic stroke and have worse stroke outcome. However, the mechanisms through which these occur remain unknown. The aim of the study was to investigate the role of vitamin B12 deficiency in ischemic stroke outcome and mechanistic changes in a mouse model. Ten-month-old male and female mice were put on control or vitamin B12 deficient diets for 4-weeks prior to and after ischemic stroke to the sensorimotor cortex. Motor function was measured, and tissues were collected to assess potential mechanisms. All deficient mice had increased levels of total homocysteine in plasma and liver tissues. After ischemic stroke, deficient mice had impaired motor function compared to control mice. There was no difference between groups in lesion volume, however, there was an increase in total apoptosis within the ischemic region of brain tissue in male deficient mice. More neuronal survival was present in ischemic brain tissue of the deficient mice compared to controls. Additionally, there were changes in choline metabolites in ischemic brain tissue because of a vitamin B12 deficiency. The data presented in this study confirms that a vitamin B12 deficiency worsens stroke outcome in male and female mice. The mechanisms driving this change may be a result of neuronal survival and compensation in choline metabolism within the damaged brain tissue.

neuroscience↗

bioRxiv2020

Dietary folic acid deficiency impacts hippocampal morphology and cortical acetylcholine metabolism in adult male and female mice

ObjectiveOne-carbon metabolism is a metabolic network that integrates nutritional signals with biosynthesis, redox homeostasis, and epigenetics. There are sex differences in hepatic one-carbon metabolism. However, it is unclear whether there are sex differences in dietary deficiencies of one-carbon metabolism in the brain. The aim of this study was to investigate if sex modulates the effects of dietary folic acid deficiency in brain tissue using a mouse model. MethodsMale and female C57Bl/6J mice were placed on a folic acid deficient (FD) or control diet (CD) at six weeks of age. Mice were maintained on these diets for six months, after which animals were euthanized and brain tissue and serum were collected for analysis. Serum folate levels were measured. In brain tissue, hippocampal volume and morphology including Cornu Ammonis 1 and 3 (CA1; CA3), and dentate gyrus thickness were measured. Apoptosis within the hippocampus was assessed using active caspase-3 immunofluorescence staining. Additionally, cortical acetylcholine metabolism was measured in brain tissue using immunofluorescence staining of acetylcholinesterase (AChE), or choline acetyltransferase (ChAT), and neuronal nuclei (NeuN). ResultsMale and female FD mice had reduced serum levels of folate. Both males and females maintained on a FD showed a decrease in the thickness of the hippocampal CA1-CA3 region. Interestingly, there was a sex difference in the levels of active caspase-3 within the CA3 region of the hippocampus. In cortical tissue, there were increased levels of neuronal ChAT and reduced levels of AChE in FD females and male mice. ConclusionsThe results indicated that FD impacts hippocampal morphology and cortical neuronal acetylcholine metabolism. The data from our study indicate that there was only one sex difference and that was in hippocampal apoptosis. Our study provides little evidence that sex modulates the effects of dietary folate deficiency on hippocampal morphology and cortical neuronal acetylcholine metabolism.

neuroscience↗

bioRxiv2019

Methylenetetrahydrofolate reductase deficiency alters cellular response after ischemic stroke in male mice

ObjectiveElevated homocysteine concentrations are a risk factor for stroke. A common genetic polymorphism in methylenetetrahydrofolate reductase (MTHFR 677 CT) results in elevated levels of homocysteine. MTHFR plays a critical role in the synthesis of S-adenosylmethionine (SAM), a global methyl donor. Our previous work has demonstrated that Mthfr+/- mice, which model the MTHFR polymorphism in humans, are more vulnerable to ischemic damage. The aim of this study was to investigate the cellular mechanisms by which the MTHFR-deficiency changes the brain in the context of ischemic stroke injury. MethodsIn the present study, three-month-old male Mthfr+/- and wild-type littermate mice were subjected to photothrombosis (PT) damage. Four weeks after PT damage, animals were tested on behavioral tasks, in vivo imaging was performed using T2-weighted MRI, and brain tissue was collected. ResultsMthfr+/- animals used their non-impaired forepaw more during to explore the cylinder and had a larger damage volume compared to wild-type littermates. In brain tissue of Mthfr+/- mice methionine adenosyltransferase II alpha (MAT2A) protein levels were decreased within the damage hemisphere and increased levels in hypoxia induced factor 1 alpha (HIF-1) in non-damage hemisphere. There was an increased antioxidant response in the damage site as indicated by higher levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and superoxide dismutase 2 (SOD2). ConclusionsOur results suggest that Mthfr+/- mice are more vulnerable to PT-induced stroke damage through regulation of the cellular response. The increased antioxidant response we observed may be compensatory to the damage amount.

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↗