378 research outputs found

    Importance of Amphibians: A Synthesis of Their Environmental Functions, Benefits to Humans, and Need for Conservation

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    Amphibians are among the most threatened species in the world and are subjected to a substantial number of studies that have underscored their ecological and anthropocentric importance. Yet a synthesis of those aspects is in need. In this study I conducted a comprehensive literature review to investigate the importance of amphibians, including medical applications such as tissue regeneration, biomimicry of pharmaceutically useful compounds, direct socio-economic benefits, and overall ecosystem values. It is my intention to promote amphibian conservation by detailing various ecosystem services provided by amphibians and their uses to humans. Amphibians have tissue regenerative abilities, such as the ability to regrow entire limbs as adults as well as larvae, and heal cardiac, brain, spinal, and retina tissues. Study of these processes could allow the medical industry to restore sight and mobility, and to remedy neurological defects, along with many other medical discoveries that are currently under investigation. Findings have emerged detailing amphibian polypeptides that release insulin, and others that raise and lower blood pressure, showing the full scope of their pharmaceutical value is just beginning to be explored. The ecological importance of amphibians includes their association with both aquatic and terrestrial environments where matter and energy are circulated between aquatic and terrestrial habitats. Their movement cycles essential nutrients such as Phosphorus, Carbon, and Nitrogen improving the overall health and resilience of the ecosystem. In many northern forests and vernal pools, amphibians account for a greater biomass than birds, mammals, and reptiles combined. They are a central part of many food webs being both predators and prey, and being poikilotherms, they turn a greater portion of their calories into biomass compared to homeotherms. Amphibians provide many predators with a stable food and nutrient source. The large number of prey eaten daily by amphibians make them useful regulators of biomass in lower trophic levels, contributing to ecosystem stability, as well as biological control agents against pests such as mosquitos, biting flies, and crop-damaging arthropods. Their thin skin and superficial vasculature make them sensitive to environmental pollutants thereby making them useful indicator species as well. This review can help the understanding of the conservation importance of these unique animals highlighting their potential in general environmental functions as well as in the biomedical industry, which then can be used as an impetus to promote and encourage conservation

    Seeing red over black and white: popular and media representations of inter-racial relationships as precursors to racial violence

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    The recent murder in the UK of Anthony Walker attests to the lingering antipathy, indeed hostility, toward intimate inter-racial relationships, especially those involving black men and white women. Seventeen year-old Walker was brutally beaten then fatally assaulted with an axe to his head - the 'provocation' for the attack was this young black man’s relationship with his white girl friend. This paper assesses the historical and contemporary images and mythologies that continue to stigmatize inter-racial relationships. Specifically, we look at the representations disseminated through varied popular media forms. The paper suggests that these mediated constructs condition an environment that facilitates, if not encourages, violence against those in inter-racial relationships

    CRADA Final Report for CRADA Number ORNL00-0605: Advanced Engine/Aftertreatment System R&D

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    Navistar and ORNL established this CRADA to develop diesel engine aftertreatment configurations and control strategies that could meet emissions regulations while maintaining or improving vehicle efficiency. The early years of the project focused on reducing the fuel penalty associated with lean NOx trap (LNT), also known as NOx adsorber catalyst regeneration and desulfation. While Navistar pursued engine-based (in-cylinder) approaches to LNT regeneration, complementary experiments at ORNL focused on in-exhaust fuel injection. ORNL developed a PC-based controller for transient electronic control of EGR valve position, intake throttle position, and actuation of fuel injectors in the exhaust system of a Navistar engine installed at Oak Ridge. Aftertreatment systems consisting of different diesel oxidation catalysts (DOCs) in conjunction with a diesel particle filter and LNT were evaluated under quasi-steady-state conditions. Hydrocarbon (HC) species were measured at multiple locations in the exhaust system with Gas chromatograph mass spectrometry (GC-MS) and Fourier transform infrared (FTIR) spectroscopy. Under full-load, rated speed conditions, injection of fuel upstream of the DOC reduced the fuel penalty for a given level of NOx reduction by 10-20%. GC-MS showed that fuel compounds were 'cracked' into smaller hydrocarbon species over the DOC, particularly light alkenes. GC-MS analysis of HC species entering and exiting the LNT showed high utilization of light alkenes, followed by mono-aromatics; branched alkanes passed through the LNT largely unreacted. Follow-on experiments at a 'road load' condition were conducted, revealing that the NOx reduction was better without the DOC at lower temperatures. The improved performance was attributed to the large swings in the NOx adsorber core temperature. Split-injection experiments were conducted with ultra-low sulfur diesel fuel and three pure HC compounds: 1-pentene, toluene, and iso-octane. The pure compound experiments confirmed the previous results regarding hydrocarbon reactivity: 1-pentene was the most efficient LNT reductant, followed by toluene. Injection location had minimal impact on the reactivity of these two compounds. Iso-octane was an ineffective LNT reductant, requiring high doses (resulting in high HC emissions) to achieve reasonable NOx conversions. Diesel fuel reactivity was sensitive to injection location, with the best performance achieved through fuel injection downstream of the DOC. This configuration generated large LNT temperature excursions, which probably improved the efficiency of the NOx storage/reduction process, but also resulted in very high HC emissions. The ORNL team demonstrated an LNT desulfation under 'road load' conditions using throttling, EGR, and in-pipe injection of diesel fuel. Flow reactor characterization of core samples cut from the front and rear of the engine-aged LNT revealed complex spatially dependent degradation mechanisms. The front of the catalyst contained residual sulfates, which impacted NOx storage and conversion efficiencies at high temperatures. The rear of the catalyst showed significant sintering of the washcoat and precious metal particles, resulting in lower NOx conversion efficiencies at low temperatures. Further flow reactor characterization of engine-aged LNT core samples established that low temperature performance was limited by slow release and reduction of stored NOx during regeneration. Carbon monoxide was only effective at regenerating the LNT at temperatures above 200 C; propene was unreactive even at 250 C. Low temperature operation also resulted in unselective NOx reduction, resulting in high emissions of both N{sub 2}O and NH{sub 3}. During the latter years of the CRADA, the focus was shifted from LNTs to other aftertreatment devices. Two years of the CRADA were spent developing detailed ammonia SCR device models with sufficient accuracy and computational efficiency to be used in development of model-based ammonia injection control algorithms.ORNL, working closely with partners at Navistar and M

    An examination of five theoretical foundations associated with localized thermosensory testing

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    Purpose: To assess five theoretical foundations underlying thermosensory testing using local thermal stimuli. Methods: Thermal sensation, discomfort and the confidence of thermal sensation scores were measured in 9 female and 8 male volunteers in response to 17 physical contact temperature stimuli, ranging between 18–42 °C. These were applied to their dorsal forearm and lateral torso, across two sessions. Results: Thermal sensation to physical temperature relationships followed a positive linear and sigmoidal fit at both forearm (r2 = 0.91/r2 = 0.91, respectively) and lateral torso (r2 = 0.90/ r2 = 0.91, respectively). Thermal discomfort to physical temperature relationships followed second and third-order fits at both forearm (r2 = 0.33/r2 = 0.34, respectively) and lateral torso (r2 = 0.38/r2 = 0.39, respectively) test sites. There were no sex-related or regional site differences in thermal sensation and discomfort across a wide range of physical contact temperatures. The median confidence of an individual’s thermal sensation rating was measured at 86%. Conclusion: The relation between thermal sensation and physical contact temperature was well described by both linear and sigmoidal models, i.e., the distance between the thermal sensation anchors is close to equal in terms of physical temperatures changes for the range studied. Participants rated similar thermal discomfort level in both cold and hot thermal stimuli for a given increase or decrease in physical contact temperature or thermal sensation. The confidence of thermal sensation rating did not depend on physical contact temperature

    The Primary PE and School Sport Premium

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    Central to London’s successful bid to host the 2012 Olympic and Paralympic Games, was the Government’s commitment to improve competitive sport and the sporting habits of young people (Ofsted, 2014). On the 12th March 2013, the then Prime Minister, David Cameron, announced that Primary Schools in England would receive funding worth £150 million per year to create a sustainable infrastructure for long-lasting change and improve the provision of physical education (PE) and sport across all state maintained primary schools. Speaking at the time, he said: ‘We can create a culture in our schools that encourages all children to be active and enjoy sport.’ He added: ‘The Olympic and Paralympic Games marked an incredible year for this country and I will always be proud that we showed the world what Britain can do. I want to ensure the Games count for the future too and that means capitalising on the inspiration young people took from what they saw during those summer months.’: https://www.bbc.co.uk/sport/21808982 Six years on, and with a total investment now of over £1.2 billion, the Primary PE and Sport Premium (here onwards referred to as the PESS Premium) has been a defining feature of the London 2012 legacy. Invariably funding streams at this level do not last forever or in the same format, which raises significant questions about what impact the funding has had on young people since 2013. We believe that a significant investment from Government merits debate and accountability at the highest possible level and that it should acknowledge where the opportunities and shortcomings of such a policy have left us. During the years of austerity, mounting concerns have arisen over the present and long term state of children’s health and the need for the debate to be heard is now imperative. To date there has been little critical appraisal of the PESS Premium funding. This report aims to begin a necessary process and in doing so, brings together evidence from across the sector to consider the future of the PESS Premium post 2018. During the course of the report, we outline and underpin the holistic value and importance of PE for every child. We examine the historic status and funding of PE and Sport and the nature and increasing diversity of the workforce. How has the PESS Premium funding impacted the way in which the subject is regarded and the ability of those tasked with delivering it to discharge their responsibilities? We have uncovered an abiding uncertainty about the nature of the PESS Premium itself; the ways in which it may be spent and its effect on an increasing divide between PE specialists, generalists and externally contracted coaches. Will its legacy be to have established a secure foundation for lifelong physical activity, sport and education – or is it, in effect, another temporarily seductive mirage, leaving PE precisely where it has become accustomed to be; regularly sidelined, delivered largely by those who are not qualified teachers and perpetuating the status quo for the children who already belong to groups that are perceived to be at a disadvantage? The PESS Premium funding is a significant sum and these questions deserve answers. This report is therefore our contribution to an essential debate, containing practical suggestions that we hope will be of use to policy makers. We invite all who care about the physical and mental health and emotional wellbeing of children to join the discussion

    LSST Science Book, Version 2.0

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    A survey that can cover the sky in optical bands over wide fields to faint magnitudes with a fast cadence will enable many of the exciting science opportunities of the next decade. The Large Synoptic Survey Telescope (LSST) will have an effective aperture of 6.7 meters and an imaging camera with field of view of 9.6 deg^2, and will be devoted to a ten-year imaging survey over 20,000 deg^2 south of +15 deg. Each pointing will be imaged 2000 times with fifteen second exposures in six broad bands from 0.35 to 1.1 microns, to a total point-source depth of r~27.5. The LSST Science Book describes the basic parameters of the LSST hardware, software, and observing plans. The book discusses educational and outreach opportunities, then goes on to describe a broad range of science that LSST will revolutionize: mapping the inner and outer Solar System, stellar populations in the Milky Way and nearby galaxies, the structure of the Milky Way disk and halo and other objects in the Local Volume, transient and variable objects both at low and high redshift, and the properties of normal and active galaxies at low and high redshift. It then turns to far-field cosmological topics, exploring properties of supernovae to z~1, strong and weak lensing, the large-scale distribution of galaxies and baryon oscillations, and how these different probes may be combined to constrain cosmological models and the physics of dark energy.Comment: 596 pages. Also available at full resolution at http://www.lsst.org/lsst/sciboo

    The development of a HAMstring InjuRy (HAMIR) index to mitigate injury risk through innovative imaging, biomechanics, and data analytics : Protocol for an observational cohort study

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    Background The etiology of hamstring strain injury (HSI) in American football is multi-factorial and understanding these risk factors is paramount to developing predictive models and guiding prevention and rehabilitation strategies. Many player-games are lost due to the lack of a clear understanding of risk factors and the absence of effective methods to minimize re-injury. This paper describes the protocol that will be followed to develop the HAMstring InjuRy (HAMIR) index risk prediction models for HSI and re-injury based on morphological, architectural, biomechanical and clinical factors in National Collegiate Athletic Association Division I collegiate football players. Methods A 3-year, prospective study will be conducted involving collegiate football student-athletes at four institutions. Enrolled participants will complete preseason assessments of eccentric hamstring strength, on-field sprinting biomechanics and muscle–tendon volumes using magnetic-resonance imaging (MRI). Athletic trainers will monitor injuries and exposure for the duration of the study. Participants who sustain an HSI will undergo a clinical assessment at the time of injury along with MRI examinations. Following completion of structured rehabilitation and return to unrestricted sport participation, clinical assessments, MRI examinations and sprinting biomechanics will be repeated. Injury recurrence will be monitored through a 6-month follow-up period. HAMIR index prediction models for index HSI injury and re-injury will be constructed. Discussion The most appropriate strategies for reducing risk of HSI are likely multi-factorial and depend on risk factors unique to each athlete. This study will be the largest-of-its-kind (1200 player-years) to gather detailed information on index and recurrent HSI, and will be the first study to simultaneously investigate the effect of morphological, biomechanical and clinical variables on risk of HSI in collegiate football athletes. The quantitative HAMIR index will be formulated to identify an athlete’s propensity for HSI, and more importantly, identify targets for injury mitigation, thereby reducing the global burden of HSI in high-level American football players. Trial Registration The trial is prospectively registered on ClinicalTrials.gov (NCT05343052; April 22, 2022)

    Using a real-world network to model localized COVID-19 control strategies

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    Case isolation and contact tracing can contribute to the control of COVID-19 outbreaks1,2. However, it remains unclear how real-world social networks could influence the effectiveness and efficiency of such approaches. To address this issue, we simulated control strategies for SARS-CoV-2 transmission in a real-world social network generated from high-resolution GPS data that were gathered in the course of a citizen-science experiment3,4. We found that tracing the contacts of contacts reduced the size of simulated outbreaks more than tracing of only contacts, but this strategy also resulted in almost half of the local population being quarantined at a single point in time. Testing and releasing non-infectious individuals from quarantine led to increases in outbreak size, suggesting that contact tracing and quarantine might be most effective as a ‘local lockdown’ strategy when contact rates are high. Finally, we estimated that combining physical distancing with contact tracing could enable epidemic control while reducing the number of quarantined individuals. Our findings suggest that targeted tracing and quarantine strategies would be most efficient when combined with other control measures such as physical distancing

    Basic science232. Certolizumab pegol prevents pro-inflammatory alterations in endothelial cell function

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    Background: Cardiovascular disease is a major comorbidity of rheumatoid arthritis (RA) and a leading cause of death. Chronic systemic inflammation involving tumour necrosis factor alpha (TNF) could contribute to endothelial activation and atherogenesis. A number of anti-TNF therapies are in current use for the treatment of RA, including certolizumab pegol (CZP), (Cimzia ®; UCB, Belgium). Anti-TNF therapy has been associated with reduced clinical cardiovascular disease risk and ameliorated vascular function in RA patients. However, the specific effects of TNF inhibitors on endothelial cell function are largely unknown. Our aim was to investigate the mechanisms underpinning CZP effects on TNF-activated human endothelial cells. Methods: Human aortic endothelial cells (HAoECs) were cultured in vitro and exposed to a) TNF alone, b) TNF plus CZP, or c) neither agent. Microarray analysis was used to examine the transcriptional profile of cells treated for 6 hrs and quantitative polymerase chain reaction (qPCR) analysed gene expression at 1, 3, 6 and 24 hrs. NF-κB localization and IκB degradation were investigated using immunocytochemistry, high content analysis and western blotting. Flow cytometry was conducted to detect microparticle release from HAoECs. Results: Transcriptional profiling revealed that while TNF alone had strong effects on endothelial gene expression, TNF and CZP in combination produced a global gene expression pattern similar to untreated control. The two most highly up-regulated genes in response to TNF treatment were adhesion molecules E-selectin and VCAM-1 (q 0.2 compared to control; p > 0.05 compared to TNF alone). The NF-κB pathway was confirmed as a downstream target of TNF-induced HAoEC activation, via nuclear translocation of NF-κB and degradation of IκB, effects which were abolished by treatment with CZP. In addition, flow cytometry detected an increased production of endothelial microparticles in TNF-activated HAoECs, which was prevented by treatment with CZP. Conclusions: We have found at a cellular level that a clinically available TNF inhibitor, CZP reduces the expression of adhesion molecule expression, and prevents TNF-induced activation of the NF-κB pathway. Furthermore, CZP prevents the production of microparticles by activated endothelial cells. This could be central to the prevention of inflammatory environments underlying these conditions and measurement of microparticles has potential as a novel prognostic marker for future cardiovascular events in this patient group. Disclosure statement: Y.A. received a research grant from UCB. I.B. received a research grant from UCB. S.H. received a research grant from UCB. All other authors have declared no conflicts of interes
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