1,213 research outputs found

    Membrane fatty acid composition and longevity of mammals and birds

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    The fatty acid composition of membrane lipids varies systematically among species in a manner that is consistent with their metabolic rate and longevity. Because the susceptibility of fatty acids to peroxidation relates directly to their extent of unsaturation, it is possible to calculate a peroxidation index (PI) for membranes through characterization of their specific fatty acid composition. Long-living mammals and birds have membrane lipids with a lower PI than shorter-living species. Bird and mammal species with the same maximum life span also have membrane lipids with essentially the same PI. Exceptionally long-living mammals and birds usually have membrane lipids high in monounsaturates, but low in polyunsaturates, with the consequence that the PI of their membrane lipids is as low as expected for their respective longevity. Longevity variation within species (whether due to calorie-restriction, extended longevity associated with specific strains, queen-worker differences in honey bees or inherited longevity differences among humans) is also associated with differences in membrane composition and PI. Membrane composition is specific for each species and PI appears to generally be resistant to dietary manipulation. It is postulated that membrane fatty acid composition is an important influence on aging and the determination of maximum life span

    Science and RE teachers' perspectives on the purpose of RE on the secondary school curriculum in England

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    Renewed interest in curriculum in English schooling over the past decade has emanated from a particular focus on the place and role of knowledge in the classroom. Significant changes in policy and examination specifications have led to changes in religious education (RE). However, little is known about teachers' perspectives on the purpose of RE. We asked teachers of science and RE what they understood as the purpose of RE on the school curriculum. Data from 10 focus groups and a survey with 276 secondary teachers demonstrated that many secondary teachers of science have a different understanding to RE teachers of the purpose of RE on the school curriculum. Findings also show a lack of consensus from RE teachers on the purpose of RE, suggesting the impact of the knowledge turn in RE is not as strong as the Ofsted Research Review implies. Findings are significant as little is known about how knowledge works across disciplinary boundaries in schools. If students are to come to a full understanding of how knowledge works, teachers need to have some understanding of how knowledge is being constructed and utilised in other curriculum subjects. Knowledge of the intended purpose of RE is important for respectful co-existence of subjects on the curriculum and essential when RE is declining as a subject in secondary schools

    Effects of milk, pasteurized milk, and milk replacer on health and productivity of dairy calves

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    Our objectives were to determine the health and blood parameters before, during, and after weaning of 114 Holstein heifers fed either accelerated milk replacer (MR; 28% CP, 18% fat) or non-saleable milk (3.59 ± 0.28% true protein; 4.12 ± 0.37% fat) that was either pasteurized (PM) or raw (RM; refrigerated and fed \u3c24 h after collection). Calves were randomly assigned to feeding treatments at birth. Colostrum (1 L) was fed less than 14 hours after birth (MR and PM = pasteurized colostrum; RM = raw colostrum). All calves were bottle-fed 1.8 ± 0.20 L, 3 times daily; all calves were provided fresh water and grain ad libitum throughout the experiment. Calves began step-down weaning at age 5 weeks and completed weaning at age 6 weeks. Blood samples were collected at ages 3, 5, and 7 weeks and were analyzed for complete blood counts (CBC) using a Procyte Idexx Analyzer (IDEXX Laboratories, Inc., Westbrook, ME). Fecal scores were observed twice daily, on a 1 to 3 scale (FS1 = normal, FS2 = loose, FS3 = scours). Results showed that MR-fed calves had more (P \u3c 0.01) observations (%obs) with FS \u3e 2 than the PM- and RM-fed calves (2.3 vs. 1.6 and 1.7 ± 0.2 %obs, respectively). In addition, there were no differences in body weight or shoulder or hip height between treatments, but a treatment x week interaction (P = 0.05) occurred for grain consumed, with a noticeably higher increase between 6 and 7 weeks of age for MR calves. When CBC was considered, there were no differences in blood cell types, but MR-fed calves had greater mean corpuscular volume (MCV) than the other calves (P \u3c 0.01), leading to higher resistance for iron deficiency anemia. In conclusion, these findings suggest that calf performance and feed intake are not affected by the administration of raw milk, pasteurized milk, or milk replacer. Moreover, CBC health parameters showed no significant changes due to administration of the different types of milk sources.; Dairy Day, 2014, Kansas State University, Manhattan, KS, 2014; Dairy Research, 2014 is known as Dairy Day, 201

    Participant experiences of the DWELL programme: focus group findings on motivation, experiences, facilitators and barriers

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    Initiatives to increase effective, low-cost self-management are essential to the sustainability of care for type 2 diabetes (T2D), however research shows that there is currently no standard approach. The DWELL programme seeks to motivate and empower people with T2D to better self-manage their condition through focussed content underpinned by motivational interviewing. As part of the DWELL evaluation study, end-of-programme focus groups were conducted to elicit participant experiences. 33 focus groups with 153 participants (including a small number of partners) took place in the two UK DWELL delivery sites. The focus group data was subjected to thematic content analysis to elicit key themes. Findings indicate that DWELL participants are motivated through a desire for better knowledge and management of their diabetes. Facilitating factors of the programme include: facilitator and peer support; the holistic and autonomous approach which provides participants with the opportunity to better understand the condition and its impact on their whole lives; and a tailored individual approach. Barriers and suggested improvements include content and operational changes, which are fed back to DWELL facilitators as part of the process evaluation in order that they can continually update the programme. Participants report positive outcomes in terms of wellbeing, social and mental health, enhanced knowledge and positive lifestyle changes. These themes align with quantitative outcome measures for participants, including weight loss, reduced BMI and glycated haemoglobin (HbA1c), enhanced empowerment and improved eating behaviours and illness perceptions and control. Interim findings suggest that DWELL outcomes include improved health literacy, participant empowerment and self-management. These findings underscore the need to incorporate a holistic, tailored approach to structured patient education for T2D

    Phonon Band Structure and Thermal Transport Correlation in a Layered Diatomic Crystal

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    To elucidate the relationship between a crystal's structure, its thermal conductivity, and its phonon dispersion characteristics, an analysis is conducted on layered diatomic Lennard-Jones crystals with various mass ratios. Lattice dynamics theory and molecular dynamics simulations are used to predict the phonon dispersion curves and the thermal conductivity. The layered structure generates directionally dependent thermal conductivities lower than those predicted by density trends alone. The dispersion characteristics are quantified using a set of novel band diagram metrics, which are used to assess the contributions of acoustic phonons and optical phonons to the thermal conductivity. The thermal conductivity increases as the extent of the acoustic modes increases, and decreases as the extent of the stop bands increases. The sensitivity of the thermal conductivity to the band diagram metrics is highest at low temperatures, where there is less anharmonic scattering, indicating that dispersion plays a more prominent role in thermal transport in that regime. We propose that the dispersion metrics (i) provide an indirect measure of the relative contributions of dispersion and anharmonic scattering to the thermal transport, and (ii) uncouple the standard thermal conductivity structure-property relation to that of structure-dispersion and dispersion-property relations, providing opportunities for better understanding of the underlying physical mechanisms and a potential tool for material design.Comment: 30 pages, 10 figure

    Directions of zero thermal expansion in anisotropic oxides

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    Figure 13. – Quadric surface visualizing the coefficients of thermal expansion of HfTiO4 at room temperature. Blue is positive, red is negative and yellow represents directions of zero thermal expansion. Oxide materials often have anisotropic crystal structures, which can result in direction-dependent material properties. While they typically have positive coefficients of thermal expansion, it has been observed that some oxide materials can have directions of negative thermal expansion over certain temperature ranges. Such materials, having both positive and negative coefficients of thermal expansion, must also have particular directions in which the thermal expansion is zero. Using the Quadrupole Lamp Furnace (QLF) developed in the Kriven group at the University of Illinois at Urbana Champaign, high-temperature in-situ x-ray diffraction has been performed at the National Synchrotron Light Source II (NSLS II) X-ray powder diffraction beamline (XPD – 28-ID) to track directions of zero thermal expansion in orthorhombic HfTiO4. These results have important implications for the design of composites for high-temperature applications. Please click Additional Files below to see the full abstract

    ASpect: A new spectrum and line analysis package for IRAF

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    We examined several publicly available spectral analysis software packages looking for one with enough functionality and versatility to meet the analysis needs of astronomers during the next decade. None of those examined can satisfactorily support the wide variety of panchromatic science programs that are now becoming possible. Furthermore, we concluded that none of these packages can be simply modified to include critical functions because of their original (limited) designs. During the next two years we will write a new spectral analysis package, ASpect, that will incorporate the latest analysis techniques for astronomical spectra in all wavelength domains. The ASpect package has several functional requirements. It must operate on spectra from a wide variety of ground-based and space-based instruments spanning wavelengths from radio to gamma rays. It must accommodate non-linear dispersion relations. It must provide a variety of functions, individually or in combination, with which to fit spectral features and the continuum. It is vitally important that known bad data be masked and that, uncertainties be propagated throughout the calculations in order for astronomers to evaluate the reliability of results. Finally, this new package must provide a powerful, intuitive graphical user interface to handle the burden of data input/output (I/O), on-line 'help,' selection of relevant features for analysis, plotting and graphical interaction, and data base management--all in a comprehensible environment. We anticipate that ASpect will take the form of an external package in IRAF (such as the NOAO and STSDAS packages) and will be layered upon the IRAF virtual Operating System to make it available on as many platforms as possible, while making it resistant to changes in operating systems and compilers. Our choice of IRAF is motivated by its portability, its wide use within the astronomical community, and its rich set of existing user applications

    Making sense of big questions that require multiple subjects: preliminary theorisation of an integrative philosophy of knowledge and empirical indications of a lack of subject connection within school curricula

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    This paper provides theorisation about a novel concept for education: an integrative philosophy of knowledge (IPK). This is proposed for school curricula to relate multiple subjects to big questions of personal and existential importance. Critical contemporary issues such as climate change education require multiple subject contributions but there is little clarity in the English education guidance on this drawing together, beyond the encouragement to do so in priority areas. Leading British thinkers have engaged the idea of the unity of knowledge, not without difficulty and criticism. The paper identifies reasons for a practical approach to consilience in school curricula. In addition to preliminary theorisation, in methodological ‘harmony’, this paper adds tentative empirical findings from a related research project that provides quantitative indications that such multi-subject connection is likely not happening. The findings are not definitive, but the perceptions of three groups of beginning and experienced teachers (secondary Religious Education (RE), secondary science and primary teachers) indicate that school curricula do not reflect an integrative approach to climate change education, and sex and relationships education, despite policy priority. A significant national survey could not detect many signs of connection. The paper speculates that RE could have a key epistemic role for the curriculum as a whole in this regard

    Effects of milk, pasteurized milk, and milk replacer on health and productivity of dairy calves

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    Dairy Research, 2014 is known as Dairy Day, 2014Our objectives were to determine the health and blood parameters before, during, and after weaning of 114 Holstein heifers fed either accelerated milk replacer (MR; 28% CP, 18% fat) or non-saleable milk (3.59 ± 0.28% true protein; 4.12 ± 0.37% fat) that was either pasteurized (PM) or raw (RM; refrigerated and fed <24 h after collection). Calves were randomly assigned to feeding treatments at birth. Colostrum (1 L) was fed less than 14 hours after birth (MR and PM = pasteurized colostrum; RM = raw colostrum). All calves were bottle-fed 1.8 ± 0.20 L, 3 times daily; all calves were provided fresh water and grain ad libitum throughout the experiment. Calves began step-down weaning at age 5 weeks and completed weaning at age 6 weeks. Blood samples were collected at ages 3, 5, and 7 weeks and were analyzed for complete blood counts (CBC) using a Procyte Idexx Analyzer (IDEXX Laboratories, Inc., Westbrook, ME). Fecal scores were observed twice daily, on a 1 to 3 scale (FS1 = normal, FS2 = loose, FS3 = scours). Results showed that MR-fed calves had more (P < 0.01) observations (%obs) with FS > 2 than the PM- and RM-fed calves (2.3 vs. 1.6 and 1.7 ± 0.2 %obs, respectively). In addition, there were no differences in body weight or shoulder or hip height between treatments, but a treatment × week interaction (P = 0.05) occurred for grain consumed, with a noticeably higher increase between 6 and 7 weeks of age for MR calves. When CBC was considered, there were no differences in blood cell types, but MR-fed calves had greater mean corpuscular volume (MCV) than the other calves (P < 0.01), leading to higher resistance for iron deficiency anemia. In conclusion, these findings suggest that calf performance and feed intake are not affected by the administration of raw milk, pasteurized milk, or milk replacer. Moreover, CBC health parameters showed no significant changes due to administration of the different types of milk sources
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