188 research outputs found

    Immunohistochemical Techniques Applied to Raw and Mildly Heat Treated Meat Systems

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    Immunohistology was performed with six commercially available antibodies directed against myosins, actins and collagens. The corresponding antigens, appearing on the surface of cryo-sections from meat and meat products heat treated to different end temperatures, were visualized using these antibodies. The meat and meat products were heated from 20 °C to 80 °C. At 80 °C the meat systems were devoid of thermal transitions as judged from differential scanning calorimetric measurements. Our results showed that although reduced binding was the case for systems heated above 60 °C, the signals from the antibody labelling was still sufficiently strong to provide information about specific antigens in meat systems heated to 70-80 °C. Antibodies with a high initial affinity bound to the their respective antigens after the latter had been heated to a few degrees above their denaturation temperature as detected in a scanning calorimeter. This investigation points to the possibility of fmding sufficiently good commercial antibodies to perform immunohistology on meat products heated to temperatures between 70-80 °C. This is important as many commercial meat products are heated to end temperatures in this range. Several examples of the labelling intensity obtained on heated meat and meat products are given. In addition, an example using double labelling with antibodies to collagen III and an antibody to slow myosin in a food product heated to 75 °C is given. Problems related to non-specific staining and to non-specific effects of heat treatment are also briefly discussed

    Too cold is better than too hot: Preferred temperatures and basking behaviour in a tropical freshwater turtle

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    Thermoregulation is critical to the survival of animals. Tropical environments can be particularly thermally challenging as they reach very high, even lethal, temperatures. The thermoregulatory responses of tropical freshwater turtles to these challenges are poorly known. One common thermoregulatory behaviour is diurnal basking, which, for many species, facilitates heat gain. Recently, however, a north-eastern Australian population of Krefft's river turtles (Emydura macquarii krefftii) has been observed basking nocturnally, possibly to allow cooling. To test this, we determined the thermal preference (central 50% of temperatures selected) of E. m. krefftii in an aquatic thermal gradient in the laboratory. We then conducted a manipulative experiment to test the effects of water temperatures, both lower and higher than preferred temperature, on diurnal and nocturnal basking. The preferred temperature range fell between 25.3°C (±SD: 1.5) and 27.6°C (±1.4) during the day, and 25.3°C (±2.4) and 26.8°C (±2.5) at night. Based on this, we exposed turtles to three 24 h water temperature treatments (‘cool’ [23°C], ‘preferred’ [26°C] and ‘warm’ [29°C]) while air temperature remained constant at 26°C. Turtles basked more frequently and for longer periods during both the day and night when water temperatures were above their preferred range (the ‘warm’ treatment). This population frequently encounters aquatic temperatures above the preferred thermal range, and our results support the hypothesis that nocturnal basking is a mechanism for escaping unfavourably warm water. Targeted field studies would be a valuable next step in understanding the seasonal scope of this behaviour in a natural environment

    The Pakaru ‘Pipeline’: Māori and Pasifika Pathways within the Academy

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    We examine the academic ‘pipeline’ for Māori and Pasifika graduates and illustrate the chronic under-representation of Māori and Pasifika in permanent academic positions in New Zealand universities. We identify areas within higher education where significant opportunities are being lost for the recruitment and retention of Māori and Pasifika. The narratives of Māori and Pasifika post-doctoral researchers, research associates and professional teaching fellows provide further insight into the advantages and disadvantages of these positions. Lastly, we propose a Pacific alternative metaphor ‘Pacific Navigation of Academic Pathways’ based on Pacific navigation, as opposed to the more commonly used term ‘pipeline’, in order to capture the nuances of Pasifika and Māori experiences

    The Pakaru ‘Pipeline’: Māori and Pasifika Pathways within the Academy

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    We examine the academic ‘pipeline’ for Māori and Pasifika graduates and illustrate the chronic under-representation of Māori and Pasifika in permanent academic positions in New Zealand universities. We identify areas within higher education where significant opportunities are being lost for the recruitment and retention of Māori and Pasifika. The narratives of Māori and Pasifika post-doctoral researchers, research associates and professional teaching fellows provide further insight into the advantages and disadvantages of these positions. Lastly, we propose a Pacific alternative metaphor ‘Pacific Navigation of Academic Pathways’ based on Pacific navigation, as opposed to the more commonly used term ‘pipeline’, in order to capture the nuances of Pasifika and Māori experiences

    The Bacillus Subtilis K-State Promotes Stationary-Phase Mutagenesis via Oxidative Damage

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    Bacterial cells develop mutations in the absence of cellular division through a process known as stationary-phase or stress-induced mutagenesis. This phenomenon has been studied in a few bacterial models, including Escherichia coli and Bacillus subtilis; however, the underlying mechanisms between these systems differ. For instance, RecA is not required for stationary-phase mutagenesis in B. subtilis like it is in E. coli. In B. subtilis, RecA is essential to the process of genetic transformation in the subpopulation of cells that become naturally competent in conditions of stress. Interestingly, the transcriptional regulator ComK, which controls the development of competence, does influence the accumulation of mutations in stationary phase in B. subtilis. Since recombination is not involved in this process even though ComK is, we investigated if the development of a subpopulation (K-cells) could be involved in stationary-phase mutagenesis. Using genetic knockout strains and a point-mutation reversion system, we investigated the effects of ComK, ComEA (a protein involved in DNA transport during transformation), and oxidative damage on stationary-phase mutagenesis. We found that stationary-phase revertants were more likely to have undergone the development of competence than the background of non-revertant cells, mutations accumulated independently of DNA uptake, and the presence of exogenous oxidants potentiated mutagenesis in K-cells. Therefore, the development of the K-state creates conditions favorable to an increase in the genetic diversity of the population not only through exogenous DNA uptake but also through stationary-phase mutagenesis

    Primary physical education, coaches and continuing professional development

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    This is an Author's Accepted Manuscript of an article published in Sport, Education and Society, 16(4), 485 - 505, 2011, copyright @ Taylor & Francis, available online at: http://www.tandfonline.com/10.1080/13573322.2011.589645.Physical education (PE) in primary schools has traditionally been taught by qualified primary teachers. More recently, some teaching of PE in primary schools has been undertaken by coaches (mostly football coaches). These coaches hold national governing body awards but do not hold teaching qualifications. Thus, coaches may not be adequately prepared to teach PE in curriculum time. The purpose of this study was to evaluate the perceptions of a group of community-based football coaches working in primary schools for the impact of a Continuing Professional Development (CPD) programme on their ability to undertake ‘specified work’ to cover PE in primary schools. The programme focused on four areas identified as important to enable coaches to cover specified work: short- and medium-term planning, pedagogy, knowledge of the curriculum and reflection. Results showed that for the majority of coaches the CPD programme had made them more aware of the importance of these four areas and had helped to develop their knowledge and ability to put this into practice in covering planning, preparation and assessment time. However, further input is still required to develop coaches’ knowledge and understanding in all four areas, but especially their curriculum knowledge, as well as their ability to put these into practice consistently. These findings are discussed in relation to the implications of employing coaches to cover the teaching of PE in primary schools and, if employed, what CPD coaches need to develop the necessary knowledge, skill and understanding for covering specified work in schools

    Tumor infiltrating effector memory Antigen-Specific CD8+ T Cells predict response to immune checkpoint therapy

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    Immune checkpoint therapy (ICT) results in durable responses in individuals with some cancers, but not all patients respond to treatment. ICT improves CD8+ cytotoxic T lymphocyte (CTL) function, but changes in tumor antigen-specific CTLs post-ICT that correlate with successful responses have not been well characterized. Here, we studied murine tumor models with dichotomous responses to ICT. We tracked tumor antigen-specific CTL frequencies and phenotype before and after ICT in responding and non-responding animals. Tumor antigen-specific CTLs increased within tumor and draining lymph nodes after ICT, and exhibited an effector memory-like phenotype, expressing IL-7R (CD127), KLRG1, T-bet, and granzyme B. Responding tumors exhibited higher infiltration of effector memory tumor antigen-specific CTLs, but lower frequencies of regulatory T cells compared to non-responders. Tumor antigen-specific CTLs persisted in responding animals and formed memory responses against tumor antigens. Our results suggest that increased effector memory tumor antigen-specific CTLs, in the presence of reduced immunosuppression within tumors is part of a successful ICT response. Temporal and nuanced analysis of T cell subsets provides a potential new source of immune based biomarkers for response to ICT

    The traditional, the ideal and the unexplored: sport coaches’ social identity constructs in film

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    The sport coaching construct within mainstream fiction films has been described as stereotypical, reinforcing the traditional notion of the sport coach as a technician who conquers all, or a hapless individual, open to ridicule from athletes and fans. Although this depiction is also prevalent in some independent fiction films and documentaries, film sub genres such as social realism and “fly on the wall” style documentaries move away from the “Hollywood sports film structure” towards stories that focus on everyday coaching moments. Through a critical discourse analysis of two U.K. films (Bend it Like Beckham and Twenty Four Seven), both featuring sport coaches in central roles, we reflect critically on these mass media multidimensional representations in terms of the sport coaching professionalisation agenda in the U.K. and the social identification process of sport coaches within their sporting environments. Keywords: Sport coaching, film, social identification, professionalisation, coaching roles
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