98 research outputs found

    Submesoscale Instabilities in Mesoscale Eddies

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    Submesoscale processes have been extensively studied in observations and simulations of fronts. Recent idealized simulations show that submesoscale instabilities also occur in baroclinic mesoscale cyclones and anticyclones. The instabilities in the anticyclone grow faster and at coarser grid resolution than in the cyclone. The instabilities lead to larger restratification in the anticyclone than in the cyclone. The instabilities also lead to changes in the mean azimuthal jet around the anticyclone from 2-km resolution, but a similar effect only occurs in the cyclone at 0.25-km resolution. A numerical passive tracer experiment shows that submesoscale instabilities lead to deeper subduction in the interior of anticyclonic than cyclonic eddies because of outcropping isopycnals extending deeper into the thermocline in anticyclones. An energetic analysis suggests that both vertical shear production and vertical buoyancy fluxes are important in anticyclones but primarily vertical buoyancy fluxes occur in cyclones at these resolutions. The energy sources and sinks vary azimuthally around the eddies caused by the asymmetric effects of the Ekman buoyancy flux. Glider transects of a mesoscale anticyclone in the Tasman Sea show that water with low stratification and high oxygen concentrations is found in an anticyclone, in a manner that may be consistent with the model predictions for submesoscale subduction in mesoscale eddies

    Identification of tumour-associated and germ line p53 mutations in canine mammary cancer

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    Mutations of the tumour suppressor p53 gene are found in a number of spontaneous canine cancers and may contribute to increased cytogenetic alterations and tumour formation. Using reverse transcription and DNA amplification, we isolated p53 cDNA from normal and tumour tissue of ten canine mammary cancer patients. DNA sequencing identified p53 mutations in three of the ten patients. These included tumour-associated p53 gene mutations within exons 2 and 5 and a germ line deletion of exons 3 to 7. These results support a role for p53 inactivation in canine mammary tumour formation and breed predisposition to cancer. Such information could prove invaluable in the successful outbreeding of inherited predisposition to cancer in the dog. A putative polymorphism was also identified at codon 69 in exon 4 and we discuss the possibility that similar polymorphisms may be associated with human breast cancer. © 1999 Cancer Research Campaig

    Understanding the Importance of Context:A Qualitative Study of a Location-Based Exergame to Enhance School Childrens Physical Activity

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    Many public health interventions are less effective than expected in 'real life settings', yet little work is undertaken to understand the reasons why. The effectiveness of complex public health interventions can often be traced back to a robust programme theory (how and why an intervention brings about a change in outcome(s)) and assumptions that are made about the context in which it is implemented. Understanding whether effectiveness (or lack thereof) is due to the intervention or the context is hugely helpful in decisions about whether to a) modify the intervention; b) modify the context; c) stop providing the intervention. Exergames-also known as Active Video Games or AVGS-are video games which use the player's bodily movements as input and have potential to increase physical activity in children. However, the results of a recent pilot randomised controlled trial (RCT) of a location-based exergame (FitQuest) in a school setting were inconclusive; no significant effect was detected for any of the outcome measures. The aim of this study was to explore whether the programme theory for FitQuest was correct with respect to how and why it would change children's perceptions of physical activity (PA) and exercise self-efficacy in the school setting. A further aim was to investigate the features of the school setting (context) that may impact on FitQuest's implementation and effectiveness. Qualitative data (gathered during the RCT) were gathered from interviews with teachers and children, and observation of sessions using FitQuest. Thematic analysis indicated that whilst children enjoyed playing the game, engaged with goal setting within the game context and undertook low to vigorous physical activity, there were significant contextual factors that prevented it from being played as often as intended. These included environmental factors (e.g. size of the playground), school factors (cancellations due to other activities), school technology policy (rules relating to mobile phone usage) and teacher factors (engagement with the intervention). A revised logic model for the FitQuest intervention indicates how both the design of exergame technology (intervention) and features of the school environment (context) could be improved to increase chances of effectiveness in the future

    An evaluation of three One Team initiatives: Halcon, North Taunton and Wellington

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    This evaluation provides evidence that the One Team philosophy, ‘Think Differently; Do Differently’, is extremely successful in achieving its aims. This philosophy takes an all-inclusive people and residential approach to recognising issues that impact upon the wellbeing of the community. It seeks to innovate through creative initiatives that enable the community as part of the solution. The achievements that make up this success have been powerfully articulated by the community members themselves, whose voices and sentiments are echoed throughout this report. However, the degree of success of each One Team is dependent upon the commitment, knowledge, relationships and trust between the partners, including the community, as much as the support and trust between the members of the One Teams and the management of the agencies involved

    Police Education in a University Setting: Emerging Cultures and Attitudes

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    Policing in common with many other working environments are defined by a specific culture; a set of morals and principles that determine who the police are and how they perform. Earlier research focused on one monolithic culture within the police service, although it is now generally agreed that the police service encompasses a number of cultures with the negative aspects of these cultures, racism, sexism, cynicism and isolation being the main focus of the literature. A police officer's role is quite unique in that a large proportion of their role is carried out away from their colleagues or supervision. Thus, a police officer's authority is exercised by their discretionary powers, which in turn could be influenced by their education and training. This article examines new forms of police probationer training located at higher education institutions (The debate of whether the police are trained or educated is a discussion that is beyond the scope of this article. For the purposes of this article, the generic term of police education is used to refer to police student training.) in relation to emerging cultures and attitudes. Drawing upon three discrete research projects undertaken by independent researchers at different university sites, it demonstrates that police education, although delivered locally and in partnership with higher education institutions can still provide a location in which aspects of police culture can flourish. The authors conclude that as new partnerships form and new methods in the delivery of recruitment training are explored, different sub-cultures are created, raising the question what does the future hold for the training offered in higher education institutions and its impact on police culture and attitudes for police student officers

    What Limits the Distribution of Liriomyza huidobrensis and Its Congener Liriomyza sativae in Their Native Niche : When Temperature and Competition Affect Species' Distribution Range in Guatemala

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    Factors limiting distribution range for most species are generally unknown regardless of whether they are native or invasive. We studied factors that could enable or restrict the distribution of two cosmopolitan invasive leafminer fly species, Liriomyza huidobrensis (Blanchard) and Liriomyza sativae (Blanchard) in their native niche. In order to test which ecological and environmental factors affect leafminer distribution we conducted thermal tolerance assays, sampled along elevation gradients and modeled species distribution. Findings from the field and rearing chambers showed a physiological restriction due to high temperatures for L. huidobrensis at 28-29 °C, above which adult emergence is compromised. We also found that maximum temperatures below 22 °C, typical of tropical highlands, favored L. huidobrensis. L. sativae was found across a wider temperature range (i.e., from 21 to 36 °C) in Guatemala. Our finding of a physiological threshold in temperature for L. huidobrensis may enable us to predict its invasive risk when combined with the environmental conditions at horticultural ports of entry and the global agricultural landscape. Further, it strengthens our predictions on shifts in distribution of the leafminer fly under future climate. We also found a temperature mediated competitive exclusion interaction between the two herbivore species, where L. sativae occurred at temperatures < 22 °C only in the absence of L. huidobrensis. We show that parasitoids had a negative effect on the leafminer flies, which varied with host plant. Finally, we show the importance of taking a multiaspect approach when investigating what limits distribution and invasiveness of a species.</p
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