467 research outputs found

    Punishing an error improves learning: The influence of punishment magnitude on error-related neural activity and subsequent learning

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    Punishing an error to shape subsequent performance is a major tenet of individual and societal level behavioral interventions. Recent work examining error-related neural activity has identified that the magnitude of activity in the posterior medial frontal cortex (pMFC) is predictive of learning from an error, whereby greater activity in this region predicts adaptive changes in future cognitive performance. It remains unclear how punishment influences error-related neural mechanisms to effect behavior change, particularly in key regions such as pMFC, which previous work has demonstrated to be insensitive to punishment. Using an associative learning task that provided monetary reward and punishment for recall performance, we observed that when recall errors were categorized by subsequent performance— whether the failure to accurately recall a number–location association was corrected at the next presentation of the same trial—the magnitude of error-related pMFC activity predicted future correction. However, the pMFC region was insensitive to the magnitude of punishment an error received and it was the left insula cortex that predicted learning from the most aversive outcomes. These findings add further evidence to the hypothesis that error-related pMFC activity may reflect more than a prediction error in representing the value of an outcome. The novel role identified here for the insular cortex in learning from punishment appears particularly compelling for our understanding of psychiatric and neurologic conditions that feature both insular cortex dysfunction and a diminished capacity for learning from negative feedback or punishment. Copyright©2010 the author

    Impact of ‘DEALTS2’ education intervention on trainer dementia knowledge and confidence to utilise innovative training approaches: A national pre-test – post-test survey

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    Background Gaps in acute care staff knowledge, skills, and attitudes towards dementia exist. Innovative training approaches that improve the delivery of care for people with dementia are needed. We were commissioned by Health Education England to develop and evaluate a new dementia education intervention ‘Dementia Education And Learning Through Simulation 2’ (DEALTS2), a simulation toolkit to enhance delivery of dementia training nationally across England. Objectives Evaluate differences in trainer dementia knowledge scores pre and post training, satisfaction with DEALTS2 Train-The-Trainer (TTT) workshops and simulation toolkit, confidence to use training approaches, and spread of implementation. Design A questionnaire survey using a pre-test – post-test design with measures completed: before (pre-test); after (T1); and 12 months post training (T2). Setting Twelve one-day DEALTS2 TTT workshops delivered across England in 2017. Participants National Health Service Trust staff employed in dementia training roles (n=199 trainers). Methods Trainers attended DEALTS2 TTT workshops and received the simulation toolkit. Data were collected between 2017 and 2018 using a questionnaire capturing differences in dementia knowledge scores, Likert scales and closed-ended questions measured satisfaction, confidence and implementation. Data were analysed using quantitative methods. Results Response rate was 92% (n=183) at pre-test/T1 and 26% (n=51) at T2. Trainer dementia knowledge scores increased from pre-test to T1 (p < 0.001) and were retained after 12 months in 5 of the 6 areas measured (pre-test to T2, p < 0.002); largest gains in ‘humanised approaches to dementia care’. 96% (n=176/183) were satisfied with DEALTS2 TTT workshops and simulation toolkit; 66.7% (n=34/51) felt confident to deliver dementia training informed by DEALTS2. Adherence rates were good with 45% (n=23/51) using the innovative training approaches within twelve months. Conclusions The results show DEALTS2 effectively increased trainer dementia knowledge and confidence to utilise innovative dementia training approaches. Implementation of DEALTS2 varied across organisations, therefore further research should explore factors determining successful implementation

    Metformin does not reduce inflammation in diabetics with abdominal aortic aneurysm or at high risk of abdominal aortic aneurysm formation

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    Introduction The protective effect of diabetes mellitus on abdominal aortic aneurysm formation and growth has been repeatedly observed in population studies but continues to be poorly understood. However, recent investigations have suggested that metformin, a staple antihyperglycemic medication, may be independently protective against abdominal aortic aneurysm formation and growth. Therefore, we describe the effect of metformin in abdominal aortic aneurysm and at-risk patients on markers of inflammation, the driver of early abdominal aortic aneurysm formation and growth. Methods Peripheral blood was collected from patients previously diagnosed with abdominal aortic aneurysm or presenting for their U.S. Preventive Task Force-recommended abdominal aortic aneurysm screening. Plasma and circulating peripheral blood mononuclear cells were isolated using Ficoll density centrifugation. Circulating plasma inflammatory and regulatory cytokines were assessed with enzyme-linked immunosorbent assays. CD4+ cell phenotyping was performed using flow cytometric analysis and expressed as a proportion of total CD4+ cells. To determine the circulating antibody to self-antigen response, a modified enzyme-linked immunosorbent assay was performed against antibodies to collagen type V and elastin fragments. Results Peripheral blood was isolated from 266 patients without diabetes mellitus (n=182), with diabetes mellitus not treated with metformin (n=34), and with diabetes mellitus actively taking metformin (n=50) from 2015 to 2017. We found no differences in the expression of Tr1, Th17, and Treg CD4+ fractions within diabetics ± metformin. When comparing inflammatory cytokines, we detected no differences in IL-1β, IL-6, IL-17, IL-23, IFN-γ, and TNF-α. Conversely, no differences were observed pertaining to the expression to regulatory cytokines IL-4, IL-10, IL-13, TSG-6, or TGF-β. Lastly, no differences in expression of collagen type V and elastin fragment antigen and/or antibodies were detected with metformin use in diabetics. Conclusion Metformin in diabetics at-risk for abdominal aortic aneurysm or diagnosed with abdominal aortic aneurysm does not seem to alter the peripheral inflammatory environment

    Cryopreserved Homografts in Infected Infrainguinal Fields Are Associated with Frequent Reinterventions and Poor Amputation-Free Survival

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    Background Single-length saphenous vein continues to be the conduit of choice in infected-field critical limb ischemia. However, half of these individuals have inadequate vein secondary to previous use or chronic venous disease. We reviewed our outcomes of infected-field infrainguinal bypasses performed with cryopreserved homografts (CHs), a widely accepted alternative to autogenous vein in this setting. Methods This is a retrospective, institutional descriptive analysis of infected-field infrainguinal revascularizations between 2012 and 2015. Results Twenty-four operations were performed in the same number of patients for limb ischemia with signs of active infection. The mean age of the cohort examined was 62.5 ± 14.4 (standard deviation) years. Mean Society of Vascular Surgery risk score was 3.9 with a baseline Rutherford's chronic ischemia score of 4.3 at presentation. Emergent procedures constituted 29% of cases, and the remainder cases were urgent procedures. The CH bypass captured was a reoperative procedure in all but one of the patients. Culture positivity was present in 75% of cases with Staphylococcus aureus (29%), the most commonly isolated organism. Thirty-day mortality and major adverse cardiovascular events were both 4%. Amputation-free survival (AFS) was 75% at 30 days. Similarly, 30-day reintervention was 38% with debridement (43%) and bleeding (29%), the most common indications. Average duration of follow-up was 27.9 ± 20.4 months (range: 0.5–60.4). Mean length of stay was 14.8 days. Reinfection requiring an additional procedure or antibiotic regimen separate from the index antibiotic course was 13%. Primary patency and AFS at 1 year was 50% and 58%, respectively. Primary patency and AFS at 2 years was 38% and 52%, respectively. Limb salvage at 1 and 2 years was 70% and 65%, respectively. Fifteen patients (63%) required reintervention during the follow-up period with 40% of those subjects undergoing multiple procedures. Conclusions CHs remain a marginal salvage conduit in the setting of infection and no autogenous choices. Therefore, clinicians should individualize usage of this high-cost product in highly selected patients only

    Not All Nitrogen Is Created Equal: Differential Effects of Nitrate and Ammonium Enrichment in Coastal Wetlands

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    Excess reactive nitrogen (N) flows from agricultural, suburban, and urban systems to coasts, where it causes eutrophication. Coastal wetlands take up some of this N, thereby ameliorating the impacts on nearshore waters. Although the consequences of N on coastal wetlands have been extensively studied, the effect of the specific form of N is not often considered. Both oxidized N forms (nitrate, NO3−) and reduced forms (ammonium, NH4+) can relieve nutrient limitation and increase primary production. However, unlike NH4+, NO3− can also be used as an electron acceptor for microbial respiration. We present results demonstrating that, in salt marshes, microbes use NO3− to support organic matter decomposition and primary production is less stimulated than when enriched with reduced N. Understanding how different forms of N mediate the balance between primary production and decomposition is essential for managing coastal wetlands as N enrichment and sea level rise continue to assail our coasts

    Relationships between affiliative social behavior and hair cortisol concentrations in semi-free ranging rhesus monkeys

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    Sociality is a fundamental aspect of human behavior and health. One benefit of affiliative social relationships is reduced short-term levels of glucocorticoids (GCs), which are indicative of physiological stress. Less is known, however, about chronic GC production in relation to affiliative social behavior. To address this issue, we studied a semi-free ranging troop of rhesus macaques (Macaca mulatta) and collected hair samples to measure hair cortisol concentrations (HCCs), as a measure of chronic GC production, during routine biannual exams. We collected social behavior (both aggressive and affiliative) and hair samples for 32 adult female rhesus macaques over one year (Experiment 1). Our results indicated that adult females who initiated higher levels of social affiliation had significantly lower levels of HCCs. Neither the initiation nor the receipt of aggression were significantly related to HCCs in this study. In a second experiment we studied 28 mother-infant dyads for the first 90 days postpartum to examine mother-infant facial interactions (i.e. mutual gazing). We analyzed HCCs during weaning approximately one year later, which is a major transitional period. We found that infants that engaged in higher levels of mutual gazing in the first 90 days postpartum had significantly lower levels of HCCs during weaning. Finally, we studied 17 infant rhesus macaques (13 males) to examine whether social behavior (such as play) in the first five months of life correlated with infant HCCs over those months (Experiment 3). We found that infant males that engaged in more social play had significantly lower levels of HCCs. By relying on an animal model, our study shows that affiliative social traits are associated with lower long-term GC production. Future research should address the complex interactions between social behavior, chronic GC production, and mental and physical health

    Perioperative Outcomes are Adversely Affected by Poor Pretransfer Adherence to Acute Limb Ischemia Practice Guidelines

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    Objectives The accepted treatment for acute limb ischemia (ALI) is immediate systemic anticoagulation and timely reperfusion to restore blood flow. In this study, we describe the retrospective assessment of pretransfer management decisions by referring hospitals to an academic tertiary care facility and its impact on perioperative adverse events. Methods A retrospective analysis of ALI patients transferred to us via our Level I Vascular Emergency program from 2010 to 2013 was performed. Patient demographics, comorbidities, Rutherford ischemia classification, time to anticoagulation, and time to reperfusion were tabulated and analyzed for correlation to incidence of major adverse limb events (MALE), mortality, and bypass patency in the perioperative period (30-day postoperative). All time intervals were calculated from the onset of symptoms and categorized into three subcohorts (48 hrs). Results Eighty-seven patients with an average age of 64.0 (± 16.2) years presented to outlying hospitals and was transferred to us with lower extremity ALI. The mean delay from symptom onset to initial referring physician evaluation was 18.3 hrs. At that time of evaluation, 53.8% had Rutherford class IIA ischemia and 36.3% had class IIB ischemia. Seventy-six (87.4%) patients were started on heparin previous to transfer. However, only 44 (57.9%) patients reached therapeutic levels as measured by activated partial thromboplastin time (aPTT) prior to definitive revascularization. A delay of anticoagulation initiation >48 hrs from symptom onset was associated with increased 30-day reintervention rates compared with the <6 hrs group (66.7% vs. 23.5%; p<0.05). However, time to reperfusion had no statistically significant impact on MALE, 30-day mortality, or 30-day interventional patency in our small cohorts. Additionally, patients with a previous revascularization had a higher 30-day reintervention rate (46.5%; p<0.05). Conclusions The practice of timely therapeutic anticoagulation of patients referred for ALI from community facilities occurs less frequently than expected and is associated with an increased perioperative reintervention rate

    Neonatal face-to-face interactions promote later social behaviour in infant rhesus monkeys

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    In primates, including humans, mothers engage in face-to-face interactions with their infants, with frequencies varying both within and across species. However, the impact of this variation in face-to-face interactions on infant social development is unclear. Here we report that infant monkeys (Macaca mulatta) who engaged in more neonatal face-to-face interactions with mothers have increased social interactions at 2 and 5 months. In a controlled experiment, we show that this effect is not due to physical contact alone: monkeys randomly assigned to receive additional neonatal face-to-face interactions (mutual gaze and intermittent lip-smacking) with human caregivers display increased social interest at 2 months, compared with monkeys who received only additional handling. These studies suggest that face-to-face interactions from birth promote young primate social interest and competenc

    Social science for conservation in working landscapes and seascapes

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    Biodiversity is in precipitous decline globally across both terrestrial and marine environments. Therefore, conservation actions are needed everywhere on Earth, including in the biodiversity rich landscapes and seascapes where people live and work that cover much of the planet. Integrative landscape and seascape approaches to conservation fill this niche. Making evidence-informed conservation decisions within these populated and working landscapes and seascapes requires an in-depth and nuanced understanding of the human dimensions through application of the conservation social sciences. Yet, there has been no comprehensive exploration of potential conservation social science contributions to working landscape and seascape initiatives. We use the Smithsonian Working Land and Seascapes initiative – an established program with a network of 14 sites around the world – as a case study to examine what human dimensions topics are key to improving our understanding and how this knowledge can inform conservation in working landscapes and seascapes. This exploratory study identifies 38 topics and linked questions related to how insights from place-based and problem-focused social science might inform the planning, doing, and learning phases of conservation decision-making and adaptive management. Results also show how conservation social science might yield synthetic and theoretical insights that are more broadly applicable. We contend that incorporating insights regarding the human dimensions into integrated conservation initiatives across working landscapes and seascapes will produce more effective, equitable, appropriate and robust conservation actions. Thus, we encourage governments and organizations working on conservation initiatives in working landscapes and seascapes to increase engagement with and funding of conservation social science

    Reductively Responsive siRNA-Conjugated Hydrogel Nanoparticles for Gene Silencing

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    A critical need still remains for effective delivery of RNA interference (RNAi) therapeutics to target tissues and cells. Self-assembled lipid- and polymer-based systems have been most extensively explored for transfection with small interfering RNA (siRNA) in liver and cancer therapies. Safety and compatibility of materials implemented in delivery systems must be ensured to maximize therapeutic indices. Hydrogel nanoparticles of defined dimensions and compositions, prepared via a particle molding process that is a unique off-shoot of soft lithography known as PRINT (Particle Replication in Non-wetting Templates), were explored in these studies as delivery vectors. Initially, siRNA was encapsulated in particles through electrostatic association and physical entrapment. Dose-dependent gene silencing was elicited by PEGylated hydrogels at low siRNA doses without cytotoxicity. To prevent disassociation of cargo from particles after systemic administration or during post-fabrication processing for surface functionalization, a polymerizable siRNA pro-drug conjugate with a degradable, disulfide linkage was prepared. Triggered release of siRNA from the prodrug hydrogels was observed under a reducing environment while cargo retention and integrity were maintained under physiological conditions. Gene silencing efficiency and cytocompatibility were optimized by screening the amine content of the particles. When appropriate control siRNA cargos were loaded into hydrogels, gene knockdown was only encountered for hydrogels containing releasable, target-specific siRNAs, accompanied by minimal cell death. Further investigation into shape, size, and surface decoration of siRNA-conjugated hydrogels should enable efficacious targeted in vivo RNAi therapies
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