748 research outputs found

    Investigating the impact of remote neuroanatomy education during the COVID-19 pandemic using online examination performance in a National Undergraduate Neuroanatomy Competition

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    Neuroanatomy is a notoriously challenging subject for medical students to learn. Due to the coronavirus disease-19 (COVID-19) pandemic, anatomical education transitioned to an online format. We assessed student performance in, and attitudes toward, an online neuroanatomy assessment compared to an in-person equivalent, as a marker of the efficacy of remote neuroanatomy education. Participants in the National Undergraduate Neuroanatomy Competition (NUNC) 2021 undertook two online examinations: a neuroanatomically themed multiple-choice question paper and anatomy spotter. Students completed pre- and post-examination questionnaires to gauge their attitudes toward the online competition and prior experience of online anatomical teaching/assessment. To evaluate performance, we compared scores of students who sat the online (2021) and in-person (2017) examinations, using 12 identical neuroradiology questions present in both years. Forty-six percent of NUNC 2021 participants had taken an online anatomy examination in the previous 12?months, but this did not impact examination performance significantly (p?>?0.05). There was no significant difference in examination scores between in-person and online examinations using the 12 neuroradiology questions (p?=?0.69). Fifty percent of participants found the online format less enjoyable, with 63% citing significantly fewer networking opportunities. The online competition was less stressful for 55% of participants. This study provides some evidence to suggest that student performance is not affected when undertaking online examinations and proposes that online neuroanatomy teaching methods, particularly for neuroradiology, may be equally as effective as in-person approaches within this context. Participants perceived online examinations as less stressful but raised concerns surrounding the networking potential and enjoyment of online events.Peer reviewe

    Evidence for a wide range of UV obscuration in z ~ 2 dusty galaxies from the GOODS-Herschel survey

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    Dusty galaxies at z ~ 2 span a wide range of relative brightness between rest-frame mid-infrared (8um) and ultraviolet wavelengths. We attempt to determine the physical mechanism responsible for this diversity. Dust-obscured galaxies (DOGs), which have rest-frame mid-IR to UV flux density ratios > 1000, might be abnormally bright in the mid-IR, perhaps due to prominent AGN and/or PAH emission, or abnormally faint in the UV. We use far-infrared data from the GOODS-Herschel survey to show that most DOGs with 10^12 L_Sun < L_IR < 10^13 L_Sun are not abnormally bright in the mid-IR when compared to other dusty galaxies with similar IR (8--1000um) luminosities. We observe a relation between the median IR to UV luminosity ratios and the median UV continuum power-law indices for these galaxies, and we find that only 24% have specific star formation rates which indicate the dominance of compact star-forming regions. This circumstantial evidence supports the idea that the UV- and IR-emitting regions in these galaxies are spatially coincident, which implies a connection between the abnormal UV faintness of DOGs and dust obscuration. We conclude that the range in rest-frame mid-IR to UV flux density ratios spanned by dusty galaxies at z ~ 2 is due to differing amounts of UV obscuration. Of galaxies with these IR luminosities, DOGs are the most obscured. We attribute differences in UV obscuration to either: 1) differences in the degree of alignment between the spatial distributions of dust and massive stars, or 2) differences in the total dust content.Comment: 9 pages, 9 figures. Accepted by Ap

    Resolution changes relationships: Optimizing sampling design using small scale zooplankton data

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    Marine research surveys are an integral tool in understanding the marine environment. Recent technological advances have allowed the development of automated or semi-automated methods for the collection of marine data. These devices are often easily implemented on existing surveys and can collect data at finer spatiotemporal resolutions than traditional devices. We used two automated instruments: the Plankton Imager and FerryBox, to collect information on zooplankton, temperature, salinity and chlorophyll in the Celtic Sea. The resulting data were spatiotemporally aligned and merged to decreasing spatial resolutions to explore how distribution patterns and the relationship between variables change across different spatial resolutions. Relative standard deviation was used to describe variability of merged data within grid cells. All variables displayed large, area-wide spatial patterns excluding copepod size which remained consistent across the study area. Copepod biomass and abundance displayed high variations across small spatial scales. Decreasing the sampling resolution changed the description of the data where small spatial changes (those that occur over scales < 3 km) were lost and area wide patterns were emphasized. Furthermore, we found that the choice of resolution can affect both the statistical strength and significance of relationships with high variability at lower resolutions due to the mismatch between the scales of ecological processes and sampling. Determining the optimum sampling resolution to answer a specific question will be dependent upon several factors, mainly the variable measured, season, location and scale of process, which all drive variation. These considerations should be a key element of survey design, helping move towards an integrated approach for an improved understanding of ecosystem processes and gaining a more holistic description of the marine environment

    Genetic dissection of the type VI secretion system in Acinetobacter and identification of a novel peptidoglycan hydrolase, TagX, required for its biogenesis

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    The type VI secretion system (T6SS) is a widespread secretory apparatus produced by Gram-negative bacteria that has emerged as a potent mediator of antibacterial activity during interbacterial interactions. Most Acinetobacter species produce a genetically conserved T6SS, although the expression and functionality of this system vary among different strains. Some pathogenic Acinetobacter baumannii strains activate this secretion system via the spontaneous loss of a plasmid carrying T6SS repressors. In this work, we compared the expression of T6SS-related genes via transcriptome sequencing and differential proteomics in cells with and without the plasmid. This approach, together with the mutational analysis of the T6SS clusters, led to the determination of the genetic components required to elaborate a functional T6SS in the nosocomial pathogen A. baumannii and the nonpathogen A. baylyi. By constructing a comprehensive combination of mutants with changes in the T6SS-associated vgrG genes, we delineated their relative contributions to T6SS function. We further determined the importance of two effectors, including an effector-immunity pair, for antibacterial activity. Our genetic analysis led to the identification of an essential membrane-associated structural component named TagX, which we have characterized as a peptidoglycan hydrolase possessing l,d-endopeptidase activity. TagX shows homology to known bacteriophage l,d-endopeptidases and is conserved in the T6SS clusters of several bacterial species. We propose that TagX is the first identified enzyme that fulfills the important role of enabling the transit of T6SS machinery across the peptidoglycan layer of the T6SS-producing bacterium

    Towards a personalised approach in exercise-based cardiovascular rehabilitation: How can translational research help?: A ‘call to action’ from the Section on Secondary Prevention and Cardiac Rehabilitation of the European Association of Preventive Cardiology

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    The benefit of regular physical activity and exercise training for the prevention of cardiovascular and metabolic diseases is undisputed. Many molecular mechanisms mediating exercise effects have been deciphered. Personalised exercise prescription can help patients in achieving their individual greatest benefit from an exercise-based cardiovascular rehabilitation programme. Yet, we still struggle to provide truly personalised exercise prescriptions to our patients. In this position paper, we address novel basic and translational research concepts that can help us understand the principles underlying the inter-individual differences in the response to exercise, and identify early on who would most likely benefit from which exercise intervention. This includes hereditary, non-hereditary and sex-specific concepts. Recent insights have helped us to take on a more holistic view, integrating exercise-mediated molecular mechanisms with those influenced by metabolism and immunity. Unfortunately, while the outline is recognisable, many details are still lacking to turn the understanding of a concept into a roadmap ready to be used in clinical routine. This position paper therefore also investigates perspectives on how the advent of ‘big data’ and the use of animal models could help unravel interindividual responses to exercise parameters and thus influence hypothesis-building for translational research in exercisebased cardiovascular rehabilitation

    Elevated fibroblast growth factor signaling is critical for the pathogenesis of the dwarfism in Evc2/Limbin mutant mice

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    Ellis-van Creveld (EvC) syndrome is a skeletal dysplasia, characterized by short limbs, postaxial polydactyly, and dental abnormalities. EvC syndrome is also categorized as a ciliopathy because of ciliary localization of proteins encoded by the two causative genes, EVC and EVC2 (aka LIMBIN). While recent studies demonstrated important roles for EVC/EVC2 in Hedgehog signaling, there is still little known about the pathophysiological mechanisms underlying the skeletal dysplasia features of EvC patients, and in particular why limb development is affected, but not other aspects of organogenesis that also require Hedgehog signaling. In this report, we comprehensively analyze limb skeletogenesis in Evc2 mutant mice and in cell and tissue cultures derived from these mice. Both in vivo and in vitro data demonstrate elevated Fibroblast Growth Factor (FGF) signaling in Evc2 mutant growth plates, in addition to compromised but not abrogated Hedgehog-PTHrP feedback loop. Elevation of FGF signaling, mainly due to increased Fgf18 expression upon inactivation of Evc2 in the perichondrium, critically contributes to the pathogenesis of limb dwarfism. The limb dwarfism phenotype is partially rescued by inactivation of one allele of Fgf18 in the Evc2 mutant mice. Taken together, our data uncover a novel pathogenic mechanism to understand limb dwarfism in patients with Ellis-van Creveld syndrome

    Multicohort analysis of the maternal age effect on recombination

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    Several studies have reported that the number of crossovers increases with maternal age in humans, but others have found the opposite. Resolving the true effect has implications for understanding the maternal age effect on aneuploidies. Here, we revisit this question in the largest sample to date using single nucleotide polymorphism (SNP)-chip data, comprising over 6,000 meioses from nine cohorts. We develop and fit a hierarchical model to allow for differences between cohorts and between mothers. We estimate that over 10 years, the expected number of maternal crossovers increases by 2.1% (95% credible interval (0.98%, 3.3%)). Our results are not consistent with the larger positive and negative effects previously reported in smaller cohorts. We see heterogeneity between cohorts that is likely due to chance effects in smaller samples, or possibly to confounders, emphasizing that care should be taken when interpreting results from any specific cohort about the effect of maternal age on recombination
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