122 research outputs found

    Decision-making by bushveld gerbils (Gerbilliscus leucogaster)

    Get PDF
    Decision-making reflects an individual’s behavioral motivation, shaped by intrinsic and extrinsic factors. We investigated the motivation and decision-making to forage in captive bushveld gerbils (Gerbilliscus leucogaster) using an individually tailored experimental protocol. Individual gerbils were subjected to 4 experiments, where we assessed behavior and decision-making in response to: (a) food quality when resources were clumped (Experiment 1), (b) food quality when resources were scattered (Experiment 2), (c) changing food distribution (clumped vs. scattered; Experiment 3), and (d) predation risk. Each experiment comprised 4 treatments, where both cost (a weighted door) and incentive (preferred vs. nonpreferred seeds; clumped vs. scattered seeds) varied according to the mass and personal preferences of individual gerbils. We counted the number of seeds eaten, assessed the frequency of door usage, and measured the duration of exploration, vigilance, and foraging (as a proportion of total time) of gerbils in each experiment. Gerbils showed individual preferences for different seed types although all preferred sunflower or sorghum seeds. Generally, gerbils ate more seeds and used the door more frequently when the costs were low. Similarly, gerbils tended to forage more when the costs were low and predation risk was low. We also found that males, in general, were more vigilant than females in Experiments 3 and 4, likely because of risk of intrasexual competition over a high-resource patch. There was considerable individual variation in behavior, but there was also consistency in most behaviors, indicating that individual gerbils perform consistently differently to other gerbils

    Engaged followership and toxic science : exploring the effect of prototypicality on willingness to follow harmful experimental instructions

    Get PDF
    Funding: This research was supported by Economic and Social Research Council grant (ES/L003104/1), a Fellowship from the Australian Research Council (FL110100199), from funding received from the School of Management at the University of St Andrews.Drawing on the ‘engaged followership’ reinterpretation of Milgram’s work on obedience, four studies (three of which were pre-registered) examine the extent to which people’s willingness to follow an experimenter’s instructions is dependent on the perceived prototypicality of the science they are supposedly advancing. In Studies 1, 2 and 3, participants took part in a study that was described as advancing either ‘hard’ (prototypical) science (i.e., neuroscience) or ‘soft’ (non-prototypical) science (i.e., social science) before completing an online analogue of Milgram’s ‘Obedience to Authority’ paradigm. In Studies 1 and 2, participants in the neuroscience condition completed more trials than those in the social science condition. This effect was not replicated in Study 3, possibly because the timing of data collection (late 2020) coincided with an emphasis on social science’s importance in controlling COVID-19. Results of a final cross-sectional study (Study 4) indicated that participants who perceived the study as to be more prototypical of science found it more worthwhile, reported making a wider contribution by taking part, reported less dislike for the task, more happiness at having taken part, and more trust in the researchers, all of which indirectly predicted greater followership. Implications for the theoretical understanding of obedience to the toxic instructions of an authority are discussed.Publisher PDFPeer reviewe

    A sex-specific switch between visual and olfactory inputs underlies adaptive sex differences in behavior

    Get PDF
    While males and females largely share the same genome and nervous system, they differ profoundly in reproductive investments and require distinct behavioral, morphological and physiological adaptations. How can the nervous system, while bound by both developmental and biophysical constraints, produce these sexdifferences in behavior? Here we uncover a novel dimorphism in Drosophila melanogaster that allows deployment of completely different behavioral repertoires in males and females with minimum changes to circuit architecture. Sexual differentiation of only a small number of higher-order neurons in the brain leads to a change in connectivity related to the primary reproductive needs of both sexes - courtship pursuit in males and communal oviposition in females. This study explains how an apparently similar brain generates distinct behavioral repertoires in the two sexes and presents a fundamental principle of neural circuit organization that may be extended to other species

    Effects of sedentary behaviour interventions on biomarkers of cardiometabolic risk in adults: systematic review with meta-analyses.

    Get PDF
    CONTEXT/PURPOSE: Observational and acute laboratory intervention research has shown that excessive sedentary time is associated adversely with cardiometabolic biomarkers. This systematic review with meta-analyses synthesises results from free living interventions targeting reductions in sedentary behaviour alone or combined with increases in physical activity. METHODS: Six electronic databases were searched up to August 2019 for sedentary behaviour interventions in adults lasting for ≥7 days publishing cardiometabolic biomarker outcomes covering body anthropometry, blood pressure, glucose and lipid metabolism, and inflammation (54 studies). The pooled effectiveness of intervention net of control on 15 biomarker outcomes was evaluated using random effects meta-analyses in the studies with control groups not providing other relevant interventions (33 studies; 6-25 interventions analysed). RESULTS: Interventions between 2 weeks and 0.05) were also small, and beneficial in direction except for fat-free mass (≈ 0.0 kg). Heterogeneity ranged widely (I2=0.0-72.9). CONCLUSIONS: Our review of interventions targeting sedentary behaviour reductions alone, or combined with increases in physical activity, found evidence of effectiveness for improving some cardiometabolic risk biomarkers to a small degree. There was insufficient evidence to evaluate inflammation or vascular function. Key limitations to the underlying evidence base include a paucity of high-quality studies, interventions lasting for ≥12 months, sensitive biomarkers and clinical study populations (eg, type 2 diabetes). PROSPERO TRIAL REGISTRATION NUMBER: CRD42016041742.PD is supported by a National Health and Medical Research Council (NHMRC) of Australia Fellowship (#1142685) and the UK Medical Research Council [#MC_UU_12015/3]. NO, DD, GH are supported by NHMRC of Australia Fellowships (#1003960, #1078360 & #1086029). The funders had no role in the data analysis or interpretation of the results

    Reduced scleral TIMP-2 expression is associated with myopia development: TIMP-2 supplementation stabilizes scleral biomarkers of myopia and limits myopia development

    Full text link
    Purpose: The purpose of this study was to determine the endogenous regulation pattern of tissue inhibitor of metalloproteinase-2 (TIMP-2) in the tree shrew sclera during myopia development and investigate the capacity of exogenous TIMP-2 to inhibit matrix metalloproteinase-2 (MMP-2) in vitro and both scleral collagen degradation and myopia development in vivo. Methods: TIMP-2 expression in the sclera during myopia development was assessed using polymerase chain reaction. In vitro TIMP-2 inhibition of MMP-2 was investigated using a gelatinase activity plate assay and zymography. Tree shrews were injected with a collagen precursor before undergoing monocular form deprivation and concurrent daily subconjunctival injections of either TIMP-2 or vehicle to the form-deprived eye. In vivo ocular biometry changes were monitored, and scleral tissue was collected after 12 days and assayed for collagen degradation. Results: The development of myopia was associated with a mean reduction in TIMP-2 mRNA expression after 5 days of form deprivation (P < 0.01). Both activation and activity of MMP-2 were inhibited by TIMP-2 with an IC50 of 10 to 20 and 2 nM, respectively. In vivo exogenous addition of TIMP-2 significantly reduced myopia development (P < 0.01), due to reduced vitreous chamber elongation (P < 0.01). In vivo TIMP-2 treatment also significantly inhibited posterior scleral collagen degradation relative to vehicle-treated eyes (P < 0.01), with levels similar to those in control eyes. Conclusions: Myopia development in mammals is associated with reduced expression of TIMP-2, which contributes to increased degradative activity in the sclera. It follows that replenishment of this TIMP-2 significantly reduced the rate of both scleral collagen degradation and myopia development

    The structural basis of bacterial manganese import

    Get PDF
    肺炎球菌が細胞内にマンガンイオンを取り込むしくみ --膜輸送体PsaBCの立体構造の解明--. 京都大学プレスリリース. 2021-09-15.Metal ions are essential for all forms of life. In prokaryotes, ATP-binding cassette (ABC) permeases serve as the primary import pathway for many micronutrients including the first-row transition metal manganese. However, the structural features of ionic metal transporting ABC permeases have remained undefined. Here, we present the crystal structure of the manganese transporter PsaBC from Streptococcus pneumoniae in an open-inward conformation. The type II transporter has a tightly closed transmembrane channel due to “extracellular gating” residues that prevent water permeation or ion reflux. Below these residues, the channel contains a hitherto unreported metal coordination site, which is essential for manganese translocation. Mutagenesis of the extracellular gate perturbs manganese uptake, while coordination site mutagenesis abolishes import. These structural features are highly conserved in metal-specific ABC transporters and are represented throughout the kingdoms of life. Collectively, our results define the structure of PsaBC and reveal the features required for divalent cation transport

    Engaged followership and toxic science: Exploring the effect of prototypicality on willingness to follow harmful experimental instructions

    Get PDF
    Drawing on the ‘engaged followership’ reinterpretation of Milgram’s work on obedience, four studies (three of which were pre-registered) examine the extent to which people’s willingness to follow an experimenter’s instructions is dependent on the perceived prototypicality of the science they are supposedly advancing. In Studies 1, 2 and 3, participants took part in a study that was described as advancing either ‘hard’ (prototypical) science (i.e., neuroscience) or ‘soft’ (non-prototypical) science (i.e., social science) before completing an online analogue of Milgram’s ‘Obedience to Authority’ paradigm. In Studies 1 and 2, participants in the neuroscience condition completed more trials than those in the social science condition. This effect was not replicated in Study 3, possibly because the timing of data collection (late 2020) coincided with an emphasis on social science’s importance in controlling COVID-19. Results of a final cross-sectional study (Study 4) indicated that participants who perceived the study to be more prototypical of science found it more worthwhile, reported making a wider contribution by taking part, reported less dislike for the task, more happiness at having taken part, and more trust in the researchers, all of which indirectly predicted greater followership. Implications for the theoretical understanding of obedience to the toxic instructions of an authority are discussed

    Acute effects of active breaks during prolonged sitting on subcutaneous adipose tissue gene expression: an ancillary analysis of a randomised controlled trial.

    Get PDF
    Active breaks in prolonged sitting has beneficial impacts on cardiometabolic risk biomarkers. The molecular mechanisms include regulation of skeletal muscle gene and protein expression controlling metabolic, inflammatory and cell development pathways. An active communication network exists between adipose and muscle tissue, but the effect of active breaks in prolonged sitting on adipose tissue have not been investigated. This study characterized the acute transcriptional events induced in adipose tissue by regular active breaks during prolonged sitting. We studied 8 overweight/obese adults participating in an acute randomized three-intervention crossover trial. Interventions were performed in the postprandial state and included: (i) prolonged uninterrupted sitting; or prolonged sitting interrupted with 2-minute bouts of (ii) light- or (iii) moderate-intensity treadmill walking every 20 minutes. Subcutaneous adipose tissue biopsies were obtained after each condition. Microarrays identified 36 differentially expressed genes between the three conditions (fold change ≥0.5 in either direction; p < 0.05). Pathway analysis indicated that breaking up of prolonged sitting led to differential regulation of adipose tissue metabolic networks and inflammatory pathways, increased insulin signaling, modulation of adipocyte cell cycle, and facilitated cross-talk between adipose tissue and other organs. This study provides preliminary insight into the adipose tissue regulatory systems that may contribute to the physiological effects of interrupting prolonged sitting

    Developing ecosystem service indicators: experiences and lessons learned from sub-global assessments and other initiatives

    Get PDF
    People depend upon ecosystems to supply a range of services necessary for their survival and well-being. Ecosystem service indicators are critical for knowing whether or not these essential services are being maintained and used in a sustainable manner, thus enabling policy makers to identify the policies and other interventions needed to better manage them. As a result, ecosystem service indicators are of increasing interest and importance to governmental and inter-governmental processes, including amongst others the Convention on Biological Diversity (CBD) and the Aichi Targets contained within its strategic plan for 2011-2020, as well as the emerging Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES). Despite this growing demand, assessing ecosystem service status and trends and developing robust indicators is o!en hindered by a lack of information and data, resulting in few available indicators. In response, the United Nations Environment Programme World Conservation Monitoring Centre (UNEP-WCMC), together with a wide range of international partners and supported by the Swedish International Biodiversity Programme (SwedBio)*, undertook a project to take stock of the key lessons that have been learnt in developing and using ecosystem service indicators in a range of assessment contexts. The project examined the methodologies, metrics and data sources employed in delivering ecosystem service indicators, so as to inform future indicator development. This report presents the principal results of this project
    corecore