1,799 research outputs found

    Monkey Brains and Monkey Bars: An ecological approach to the values of school recess

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    Recess is a cherished part of the school day for countless children. Its value, however, has been increasingly questioned in many communities as academic performance standards and management of playground risks take precedence over play. This research examined the multiple outdoor play values held by constituents of a small, independent school for dyslexic students. Students have the choice of several recess options, including traditional playground equipment and a woodland with a stream. Ethnographic methods, including videotaped observations and interviews, were used to inquire into the values that children demonstrated through activity in their chosen play settings, as well as those expressed by their parents, teachers, school administrators and alumni. A theoretical framework of ecological psychology integrated the theory of affordances, behavior settings, and nested systems to describe the values of each group regarding outdoor play in school. Over the course of the study, most elementary students, and some middle school students, followed a longstanding pattern of selecting the woods as their preferred play setting, where they established territory and participated in practices such as creating a barter economy, foraging for human and natural artifacts (such as wood, metal, and “monkey brains”), searching for animals, constructing forts, and engaging in other forms of fun. Children selecting the playground structures (including a sport court, swings and “monkey bars”) expressed the desire for a more managed space, or for larger peer group activity. Presented as portraits of children’s encounters with their play settings, results demonstrated that the appeal of the woods setting correlated with a far greater diversity of affordances (action possibilities) than the traditional fixed play structures, as well as providing a respite from adult expectations and the opportunity to establish both personal identity and friendships in a dynamic, ongoing social setting. Adult respondents expressed commitment to the experiential learning that occurs through recess play, particularly in the woods. As schools are increasingly identified as potential havens for nurturing competent, enduring relationships with outdoor environments, this study emphasizes that the complex ecological context of schoolyard play should be considered in policy decisions affecting recess design and practice

    Mapping vaccine hesitancy—Country-specific characteristics of a global phenomenon

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    AbstractThe term vaccine hesitancy refers to delay in acceptance or refusal of vaccines despite the availability of vaccination services. Different factors influence vaccine hesitancy and these are context-specific, varying across time and place and with different vaccines. Factors such as complacency, convenience and confidence are involved. Acceptance of vaccines may be decreasing and several explanations for this trend have been proposed. The WHO Strategic Advisory Group of Experts (SAGE) on Immunization has recognized the global importance of vaccine hesitancy and recommended an interview study with immunization managers (IMs) to better understand the range of vaccine hesitancy determinants that are encountered in different settings. Interviews with IMs in 13 selected countries were conducted between September and December 2013 and various factors that discourage vaccine acceptance were identified. Vaccine hesitancy was not defined consistently by the IMs and most interpreted the term as meaning vaccine refusal. Although vaccine hesitancy existed in all 13 countries, some IMs considered its impact on immunization programmes to be a minor problem. The causes of vaccine hesitancy varied in the different countries and were context-specific, indicating a need to strengthen the capacity of national programmes to identify the locally relevant causal factors and to develop adapted strategies to address them

    Documenting head impacts in youth hockey

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    Sport-related concussions, which can result in long-lasting adverse cognitive and behavioural effects in athletes, have gained the attention of the research community since an estimated 200,000 concussions are reported in Canada each year. While concussions occur in many sports, most of the research on the mechanisms of concussive impacts has focused on football, despite double the concussion rate in hockey. Concussions in youth athletes often result in more detrimental physiological consequences compared to adults, but most research has been conducted in professional sport. With approximately half a million players registering in minor league hockey in Canada every year, concussion awareness and prevention in this susceptible population is therefore imperative to reducing health concerns. Consequently, our proposed study aims to fill this gap within the existing literature by examining head impacts in youth hockey. We will utilize a multi-camera video system to record youth hockey games at local rinks in Windsor-Essex County. From the video records, the following measures related to head impacts that occur during play will be quantified: impact type, frequency, and location; player anticipation based on body position prior to impact, and; head velocities and impact severities. Once described and quantified, these data will provide a better understanding of the mechanisms involved in head impacts in youth hockey. It is also expected that our results will help to inform the development of interventions that reduce head injury rates, including concussions, through concussion education, training in bodychecking anticipation, and possible rule changes that limit head impact potential

    Fate of Allochthonous Dissolved Organic Carbon in Lakes: A Quantitative Approach

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    Inputs of dissolved organic carbon (DOC) to lakes derived from the surrounding landscape can be stored, mineralized or passed to downstream ecosystems. The balance among these OC fates depends on a suite of physical, chemical, and biological processes within the lake, as well as the degree of recalcintrance of the allochthonous DOC load. The relative importance of these processes has not been well quantified due to the complex nature of lakes, as well as challenges in scaling DOC degradation experiments under controlled conditions to the whole lake scale. We used a coupled hydrodynamic-water quality model to simulate broad ranges in lake area and DOC, two characteristics important to processing allochthonous carbon through their influences on lake temperature, mixing depth and hydrology. We calibrated the model to four lakes from the North Temperate Lakes Long Term Ecological Research site, and simulated an additional 12 ‘hypothetical’ lakes to fill the gradients in lake size and DOC concentration. For each lake, we tested several mineralization rates (range: 0.001 d−1 to 0.010 d−1) representative of the range found in the literature. We found that mineralization rates at the ecosystem scale were roughly half the values from laboratory experiments, due to relatively cool water temperatures and other lake-specific factors that influence water temperature and hydrologic residence time. Results from simulations indicated that the fate of allochthonous DOC was controlled primarily by the mineralization rate and the hydrologic residence time. Lakes with residence times <1 year exported approximately 60% of the DOC, whereas lakes with residence times >6 years mineralized approximately 60% of the DOC. DOC fate in lakes can be determined with a few relatively easily measured factors, such as lake morphometry, residence time, and temperature, assuming we know the recalcitrance of the DOC

    The effects of peripheral and central high insulin on brain insulin signaling and amyloid-β in young and old APP/PS1 mice

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    Hyperinsulinemia is a risk factor for late-onset Alzheimer's disease (AD). In vitro experiments describe potential connections between insulin, insulin signaling, and amyloid-β (Aβ), but in vivo experiments are needed to validate these relationships under physiological conditions. First, we performed hyperinsulinemic-euglycemic clamps with concurrent hippocampal microdialysis in young, awake, behaving APP(swe)/PS1(dE9) transgenic mice. Both a postprandial and supraphysiological insulin clamp significantly increased interstitial fluid (ISF) and plasma Aβ compared with controls. We could detect no increase in brain, ISF, or CSF insulin or brain insulin signaling in response to peripheral hyperinsulinemia, despite detecting increased signaling in the muscle. Next, we delivered insulin directly into the hippocampus of young APP/PS1 mice via reverse microdialysis. Brain tissue insulin and insulin signaling was dose-dependently increased, but ISF Aβ was unchanged by central insulin administration. Finally, to determine whether peripheral and central high insulin has differential effects in the presence of significant amyloid pathology, we repeated these experiments in older APP/PS1 mice with significant amyloid plaque burden. Postprandial insulin clamps increased ISF and plasma Aβ, whereas direct delivery of insulin to the hippocampus significantly increased tissue insulin and insulin signaling, with no effect on Aβ in old mice. These results suggest that the brain is still responsive to insulin in the presence of amyloid pathology but increased insulin signaling does not acutely modulate Aβ in vivo before or after the onset of amyloid pathology. Peripheral hyperinsulinemia modestly increases ISF and plasma Aβ in young and old mice, independent of neuronal insulin signaling. SIGNIFICANCE STATEMENT The transportation of insulin from blood to brain is a saturable process relevant to understanding the link between hyperinsulinemia and AD. In vitro experiments have found direct connections between high insulin and extracellular Aβ, but these mechanisms presume that peripheral high insulin elevates brain insulin significantly. We found that physiological hyperinsulinemia in awake, behaving mice does not increase CNS insulin to an appreciable level yet modestly increases extracellular Aβ. We also found that the brain of aged APP/PS1 mice was not insulin resistant, contrary to the current state of the literature. These results further elucidate the relationship between insulin, the brain, and AD and its conflicting roles as both a risk factor and potential treatment

    GroundLink: A Dataset Unifying Human Body Movement and Ground Reaction Dynamics

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    The physical plausibility of human motions is vital to various applications in fields including but not limited to graphics, animation, robotics, vision, biomechanics, and sports science. While fully simulating human motions with physics is an extreme challenge, we hypothesize that we can treat this complexity as a black box in a data-driven manner if we focus on the ground contact, and have sufficient observations of physics and human activities in the real world. To prove our hypothesis, we present GroundLink, a unified dataset comprised of captured ground reaction force (GRF) and center of pressure (CoP) synchronized to standard kinematic motion captures. GRF and CoP of GroundLink are not simulated but captured at high temporal resolution using force platforms embedded in the ground for uncompromising measurement accuracy. This dataset contains 368 processed motion trials (~1.59M recorded frames) with 19 different movements including locomotion and weight-shifting actions such as tennis swings to signify the importance of capturing physics paired with kinematics. GroundLinkNet, our benchmark neural network model trained with GroundLink, supports our hypothesis by predicting GRFs and CoPs accurately and plausibly on unseen motions from various sources. The dataset, code, and benchmark models are made public for further research on various downstream tasks leveraging the rich physics information at https://csr.bu.edu/groundlink/

    Supernova 2008bk and its red supergiant progenitor

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    Indexación: ISIHemos obtenido pocos datos fotométricos y espectroscópicos de supernova (SN) 2008bk en NGC 7793, principalmente a 150 días después de la explosión. Nos parece que se trata de un tipo II-Plateau (II-P) SN que más se asemeja a la de baja luminosidad SN 1999br en NGC 4900. Dada la similitud general entre las curvas de luz observadas y colores de SNs 2008bk y 1999br, inferimos que la extinción total visual a SN 2008bk ( A V = 0,065 mag) debe ser casi en su totalidad debido a un primer plano galáctico, similar a lo que ha supuesto para SN 1999br. Confirmamos la identificación de la supergigante roja putativo (RSG) estrella progenitora de SN en la alta calidad de g ' r ' i imágenes "que había obtenido en 2007 en el Gemini-Sur 8 telescopio m. Existe poca ambigüedad en esta identificación progenitor, calificándolo como el mejor ejemplo hasta la fecha, junto con la identificación de la estrella Sk -69 ° 202 como el progenitor de SN 1987A. A partir de una combinación de fotometría de las imágenes de Gemini con el de archivo, pre-SN, el Telescopio Muy Grande de JHK s imágenes, derivamos una precisa distribución observada energía espectral (SED) para el progenitor. Nos encontramos con índices de nebulares fuerte intensidad de emisiones de línea para varios H II regiones cercanas a la SN que la metalicidad en el medio ambiente es probable subsolar ( Z 0.6 Z ☉ ). El SED observado de la estrella concuerda bastante bien con SED sintéticos obtenidos a partir de modelos de atmósferas RSG eficaz con temperatura T eff = 3600 ± 50 K. Nos encontramos, por tanto, que la estrella tenía una luminosidad bolométrica con respecto al Sol de log ( L bol / L ☉ ) = 4,57 ± 0,06 y el radio R = 496 ± 34 R ☉ a ~ 6 meses antes de la explosión. Al comparar las propiedades del progenitor con teóricos masiva estrella modelos evolutivos, llegamos a la conclusión de que el progenitor RSG tenía una masa inicial en el rango de 8-8,5 M ☉ . Esta masa es consistente con, aunque en el extremo bajo de la gama inferido de masas iniciales para SN II-P progenitores. También es coherente con el límite superior estimado de la masa inicial de la progenitora de SN 1999br, y concuerda con las masas iniciales bajos encontrados para los progenitores RSG de otras supernovas de baja luminosidad II-P.http://www.sherpa.ac.uk/romeo/issn/0004-6256/es/http://iopscience.iop.org/1538-3881/143/1/19

    Cognitive and Electrophysiological Correlates of the Bilingual Stroop Effect

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    The color word Stroop effect in bilinguals is commonly half the magnitude when the written and naming languages are different (between) than when they are the same (within). This between-within language Stroop difference (BWLS) is likened to a response set effect, with greater response conflict for response relevant than irrelevant words. The nature of the BWLS was examined using a bilingual Stroop task. In a given block (Experiment 1), color congruent and incongruent words appeared in the naming language or not (single), or randomly in both languages (mixed). The BWLS effect was present for both balanced and unbalanced bilinguals, but only partially supported a response set explanation. As expected, color incongruent trials during single language blocks, lead to slower response times within than between languages. However, color congruent trials during mixed language blocks led to slower times between than within languages, indicating that response-irrelevant stimuli interfered with processing. In Experiment 2, to investigate the neural timing of the BWLS effect, event related potentials were recorded while balanced bilinguals named silently within and between languages. Replicating monolingual findings, an N450 effect was observed with larger negative amplitude for color incongruent than congruent trials (350–550 ms post-stimulus onset). This effect was equivalent within and between languages, indicating that color words from both languages created response conflict, contrary to a strict response set effect. A sustained negativity (SN) followed with larger amplitude for color incongruent than congruent trials, resolving earlier for between than within language Stroop. This effect shared timing (550–700 ms), but not morphology or scalp distribution with the commonly reported sustained potential. Finally, larger negative amplitude (200–350 ms) was observed between than within languages independent of color congruence. This negativity, likened to a no-go N2, may reflect processes of inhibitory control that facilitate the resolution of conflict at the SN, while the N450 reflects parallel processing of distracter words, independent of response set (or language). In sum, the BWLS reflects brain activity over time with contributions from language and color conflict at different points

    Multicentury Fire and Forest Histories at 19 Sites in Utah and Eastern Nevada

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    Our objective is to provide site-specific fire and forest histories from Utah and eastern Nevada that can be used for land management or additional research. We systematically sampled fire scars and tree-recruitment dates across broad gradients in elevation and forest type at 13 sites in Utah and 1 in eastern Nevada to characterize spatial and temporal variation in historical fire regimes as well as forest structure and composition. We collected similar data non-systematically at five additional sites in Utah. These 19 sites include a broad range of forest types (from pinyon-juniper woodlands to spruce-fir forests) and fire regime types. In this report, we summarize local-scale spatial and temporal variation with site-specific details of historical fire regimes and forests that will be useful for local natural resource and fire management of the individual sites. For each site, we report topography, chronologies of fire and tree recruitment, and properties derived from those chronologies such as time-averaged fire regime parameters (mean fire interval and fire severity) and changes in forest composition and structure that have occurred since the late 1800s

    Up-regulation of the P2Y2 receptor by cytokines in neuronal cells

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    Abstract only availableAlzheimer's Disease (AD) is characterized by inflammation and neurodegeneration in the brain due to the presence of extracellular amyloid beta (A β) plaques and neurofibrillary tangles. Microglial and astrocyte cells associated with these plaques and tangles have been shown to release cytokines in AD patients, which have a proinflammatory effect on the brain. The P2Y2 receptor (P2Y2R) is a receptor protein that is up-regulated in response to damage or stress in a variety of tissues, including blood vessels and salivary gland epithelium. Recently our laboratory has shown that activation of the P2Y2R enhances α -secretase-dependent amyloid precursor protein (APP) processing. APP is proteolytically processed by β - and γ -secretases to release neurodegenerative A β. Alternatively, APP can be cleaved within the A β domain by α -secretase releasing the non-amyloidogenic product, sAPP α, which has been shown to have neuroprotective properties. Primary neurons have low P2Y2R expression, however, it has been demonstrated that cytokines up-regulate P2Y2R in smooth muscle cells. Therefore, this study will explore if cytokines up-regulate P2Y2R expression in primary rat neurons and in SH-SY5Y human neuroblastoma cells. Primary rat neurons and SH-SY5Y human neuroblastoma cells were plated on glass cover slips 24 or 48 hours with individual treatment, or a combination of, human interleukin-1 β (IL1- β), tumor necrosis factor α (TNF α), and interferon γ (IF γ). P2Y2R activity was measured by increases in intracellular calcium concentration ([Ca2+]i ) in response to the P2Y2R agonist UTP. Results support the hypothesis that P2Y2R is up-regulated by cytokines in neuronal cells. Furthermore, real-time PCR results indicate a two-fold increase in P2Y2R mRNA after cytokine treatment. Therefore, activation of the up-regulated P2Y2R in stressed neurons generates a neuroprotective (sAPP α) rather than neurodegenerative (A β) peptide. These results could have a substantial impact on the understanding and treatment of neurological disorders such as AD.Life Sciences Undergraduate Research Opportunity Progra
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