1,382 research outputs found

    Fission yeast SWI/SNF and RSC complexes show compositional and functional differences from budding yeast.

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    SWI/SNF chromatin-remodeling complexes have crucial roles in transcription and other chromatin-related processes. The analysis of the two members of this class in Saccharomyces cerevisiae, SWI/SNF and RSC, has heavily contributed to our understanding of these complexes. To understand the in vivo functions of SWI/SNF and RSC in an evolutionarily distant organism, we have characterized these complexes in Schizosaccharomyces pombe. Although core components are conserved between the two yeasts, the compositions of S. pombe SWI/SNF and RSC differ from their S. cerevisiae counterparts and in some ways are more similar to metazoan complexes. Furthermore, several of the conserved proteins, including actin-like proteins, are markedly different between the two yeasts with respect to their requirement for viability. Finally, phenotypic and microarray analyses identified widespread requirements for SWI/SNF and RSC on transcription including strong evidence that SWI/SNF directly represses iron-transport genes

    Developing a Diet Authentication System from the Composition of Meat in Ruminants

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    As consumer interest in the link between diet and human health and in the ethics of food production increases assurances about the background origin of food are sought. In the case of animal-derived foods, such as meat, the animal’s diet is an intrinsic component of the food’s production and of its subsequent nutritional quality. Thus, there is a need to develop ways of validating the authenticity of the animal diet. Among the approaches to authenticate the background diet of ruminants is the measurement of components in meat (muscle and adipose tissue) and other tissues that are directly influenced by the diet, including fatty acids, carotenoids, vitamins, volatile organic compounds and elemental stable isotope ratios, as well as measurement of indirect indices such as spectral properties. While each is useful in its own right, the reliability of different measurements, for diet authentication purposes, depends on the sensitivity of the analytes measured to changes in diet, and on tissue turnover in response to changes in dietary constituents. Of the analyses discussed, stable isotope analysis in muscle and incremental tissues is presented as a particularly powerful tool for diet reconstruction

    Enhancement of the Nutritional Value and Eating Quality of Beef

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    End of Project ReportThis project was supported by the European Commission (Healthy Beef, QLRT-CT-2000-31423).Consumer interest in the nutritional aspects of health has increased interest in developing methods to manipulate the fatty acid composition of ruminant products. Ruminant meats such as beef and lamb are often criticised by nutritionists for having high amounts of saturated fatty acids (S) and low polyunsaturated fatty acids (P).The P:S ratio in beef is approximately 0.1, the ideal being about 0.4. This project is part of a larger EU-supported project entitled Healthy Beef (Enhancing the content of beneficial fatty acids in beef and improving meat quality for the consumer: QLRT-CT-2000-31423). The Teagasc contribution, which was a collaboration between Grange Research Centre and The National Food Centre, focussed on nutritional manipulation of beef cattle. In particular, on exploiting grazing and fishoil as tools to enhance the concentration of “healthy” fatty acids in beef. The conclusions were: • The beneficial effect of a grazed grass-based diet on the fatty acid composition of beef was confirmed • The scale of this beneficial effect is strongly dependent on the duration of grazing • The optimum concentration of beneficial fatty acids was not achieved suggesting that feeding management prior to grazing is important • Grazing influenced beef colour and drip-loss in a durationdependent manner • Animals finished off grass for 40 or 98 days produced meat that was tougher than that from animals finished on silage and concentrates or fed grass for the last 158 days. • Fish oil supplementation enhanced the concentration in beef, of fatty acids that are beneficial to human health • The linear response to increasing level of fish oil consumption indicates scope to further enhance the concentrations of beneficial fatty acids in beef Wilting of grass prior to ensiling did not impact negatively on the overall content of n-3P in muscle, but it increased the concentration of conjugated linoleic acid • Dietary inclusion of fish oil or wilting of grass prior to ensiling did not affect muscle appearance • Fish oil seemed to increase tenderness but only at the high level of inclusion. This merits further study • There was some evidence that wilting of grass prior to ensiling enhanced meat tenderness. This needs to be confirmed.European Unio

    Lipid Oxidation and Sensory Characteristics of Grass-Fed Beef: Effect of Duration of Grazing Prior to Slaughter

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    Beef from cattle produced from grass has a higher concentration of fatty acids considered to be beneficial to human health than beef produced from more intensive production systems and this increase in fatty acid concentration is dependant on the duration at pasture prior to slaughter (Noci et al., 2003). Improvements in the fatty acid composition of beef must not impair other quality characteristics of beef. Little information is available on the pattern of change of quality characteristics in grazing animals. The objective of this study was to determine the shelf-life and eating quality of beef from cattle produced from a standard Irish grass silage/concentrates finishing system but allowed to graze grass for different periods prior to slaughter

    The State Of Higher Education In 2012

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    The higher education sector is experiencing an escalating pace of change. Even colleges and universities with the greatest resources and strongest brands are confronting change, particularly as a result of the digital revolution that is radically impacting modes of learning and accessibility to knowledge. These changes are driven by market pressures — i.e., by the demands and expectations of students and faculty. At the same time, all of higher education continues its evolution in response to ongoing price pressures, to reduced governmental support, to growing competition from the for-profit higher education sector, to its own ethical challenges, and to changes in the regulatory environment. Boards, presidents, provosts and CFOs are addressing these risks and challenges with new strategies and unique action plans that are a far cry from traditional approaches to higher education

    PACT: An initiative to introduce computational thinking to second-level education in Ireland

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    PACT (Programming ∧ Algorithms ⇒ Computational Thinking) is a partnership between researchers in the Department of Computer Science at Maynooth University and teachers at selected post-primary schools around Ireland. Starting in September 2013, seven Irish secondary schools took part in a pilot study, delivering material prepared by the PACT team to Transition Year students. Three areas of Computer Science were identified as being key to delivering a successful course in computational thinking, namely, programming, algorithms and computability. An overview of the PACT module is provided, as well as analysis of the feedback obtained from students and teachers involved in delivering the initial pilot

    The effect of additive noise on dynamical hysteresis

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    We investigate the properties of hysteresis cycles produced by a one-dimensional, periodically forced Langevin equation. We show that depending on amplitude and frequency of the forcing and on noise intensity, there are three qualitatively different types of hysteresis cycles. Below a critical noise intensity, the random area enclosed by hysteresis cycles is concentrated near the deterministic area, which is different for small and large driving amplitude. Above this threshold, the area of typical hysteresis cycles depends, to leading order, only on the noise intensity. In all three regimes, we derive mathematically rigorous estimates for expectation, variance, and the probability of deviations of the hysteresis area from its typical value.Comment: 30 pages, 5 figure

    Lamb meat colour stability as affected by dietary tannins

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    Twenty-one male Comisana lambs were divided into three groups at 45 days of age and were individually penned for 60 days. Seven lambs were fed a concentrate-based diet (C), seven lambs received the same concentrate with the addiction of tannins from quebracho (Schinopsis lorentzii; T), whereas the remaining animals were fed exclusively fresh vetch (Vicia sativa; H). Colour descriptors (a*, b* and H*) and metmyoglobin (MMb) percentages were measured on minced semimembranosus muscle over 14 days of refrigerated storage in a high oxygen atmosphere. Regardless of dietary treatment, meat redness decreased, while yellowness and hue angle increased (P < 0.001) over storage duration. However, higher a* values, lower b* values and lower H* values were observed in meat from both H- and T-fed animals as compared to meat from C-fed lambs (P = 0.012; P = 0.02; P = 0.003, respectively). Metmyoglobin formation increased over time (P < 0.001), but H diet resulted in lower metmyoglobin percentages than C diet (P = 0.007). We conclude that the inclusion of tannins into the concentrate improved meat colour stability compared to a tannin-free concentrate. Moreover, the protective effect of tannins against meat discolouration was comparable to that obtained by feeding lambs fresh herbage
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