974 resultados para Collagen I, Gelatin
Resumo:
We conducted surveys of bats in China between 1999 and 2007, resulting in the identification of at least 62 species. In this paper we present data on 19 species, comprising 12 species from the family Rhinolophidae and seven from the Hipposideridae. Rhinolophids captured were Rhinolophus affinis, R. ferrumequinum, R. lepidus, R. luctus, R. macrotis, R. siamensis, R. marshalli, R. rex, R. pearsonii, R. pusillus, R. sinicus and R. stheno. Because of extensive morphological similarities we question the species distinctiveness of R. osgoodi (may be conspecific with R. lepidus), R. paradoxolophus (which may best be treated as a subspecies of R. rex), R. huananus (probably synonymous with R. siamensis), and we are skeptical as to whether R. sinicus is distinct from R. thomasi. Hipposiderids captured were Hipposideros armiger, H. cineraceus, H. larvatus, H. pomona, H. pratti, Aselliscus stoliczkanus and Coelops frithii. Of these species, two rhinolophids (Rhinolophus marshalli and R. stheno) and one hipposiderid (Hipposideros cineraceus) represent new species records for China. We present data on species' ranges, morphology and echolocation call frequencies, as well as some notes on ecology and conservation status. China hosts a considerable diversity of rhinolophid and hipposiderid bats, yet threats to their habitats and populations are substantial.
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Anisotropy of transverse proton spin relaxation in collagen-rich tissues like cartilage and tendon is a well-known phenomenon that manifests itself as the "magic-angle" effect in magnetic resonance images of these tissues. It is usually attributed to the non-zero averaging of intra-molecular dipolar interactions in water molecules bound to oriented collagen fibers. One way to manipulate the contributions of these interactions to spin relaxation is by partially replacing the water in the cartilage sample with deuterium oxide. It is known that dipolar interactions in deuterated solutions are weaker, resulting in a decrease in proton relaxation rates. In this work, we investigate the effects of deuteration on the longitudinal and the isotropic and anisotropic contributions to transverse relaxation of water protons in bovine articular cartilage. We demonstrate that the anisotropy of transverse proton spin relaxation in articular cartilage is independent of the degree of deuteration, bringing into question some of the assumptions currently held over the origins of relaxation anisotropy in oriented tissues.
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A compelling body of studies identifies the importance of sleep for children’s learning, behavioral regulation, and health. These studies have primarily focused on nighttime sleep or on total sleep duration. The independent contribution of daytime sleep, or napping, in childhood is an emerging research focus. Daytime sleep is particularly pertinent to the context of early childhood education and care (ECEC) where, internationally, allocation of time for naps is commonplace through to the time of school entry. The biological value of napping varies with neurological maturity and with individual circumstance. Beyond the age of 3 years, when monophasic sleep patterns become typical, there is an increasing disjuncture between children’s normative sleep requirements and ECEC practice. At this time, research evidence consistently identifies an association between napping and decreased quality and duration of night sleep. We assess the implications of this evidence for educational practice and health policy. We identify the need to distinguish the functions of napping from those of rest, and assert the need for evidence-based guidelines on sleep–rest practices in ECEC settings to accommodate individual variation in sleep needs. Given both the evidence on the impact of children’s nighttime sleep on long-term trajectories of health and well-being and the high rates of child attendance in ECEC programs, we conclude that policy and practice regarding naptime have significant implications for child welfare and ongoing public health.
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The role that specific emotions, such as pride and triumph, play during instruction in science education is an under-researched field of study. Emotions are recognized as central to learning yet little is known about the way in which they are produced in naturalistic settings, how emotions relate to classroom learning during interactions, and what antecedent factors are associated with emotional experiences during instruction. Data sources for the study include emotion diaries, student written artifacts, video recordings of class interactions, and interviews. Emotions produced in the moment during classroom interactions are analyzed from video data and audio data through a novel theoretical framework related to the sociology of human emotions. These direct observations are compared with students’ recollected emotional experiences reported through emotion diaries and interviews. The study establishes links between pride and triumph within classroom interactions and instructional tasks during learning episodes in a naturalistic setting. We discuss particular classroom activities that are associated with justified feelings of pride and triumph. More specifically, classroom events associated with these emotions were related to understanding science concepts, social interactions, and achieving success on challenging tasks.
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From the early literature on the role of firm managers (Alchian and Demsetz 1972) to the industrial organisation on contracts and mechanism design (Laont and Martimort 2009), economists have given a lot of attention to find solutions to the imperfect alignment between individuals' incentives and an organisation's collective goals (Prendergast 1999). In that literature a key role of managers is to monitor individuals to reward behaviour aligned with the collective goals and reduce sub- optimal behaviour, such as shirking. How- ever, another strand of literature, since Akerlof (1982), has put forward a vision of reciprocal behaviour between an organisation's leadership and its members: gifts (high wages, recognition) from the organisation are reciprocated by high effort from the members of the organisation. By rewarding individual members (rather than strictly monitoring them), organisations may benefit from greater effort and cohesion. Experimental research in organizational economics has provided mixed results suggesting that agents do react to personal incentives but also that reciprocal behaviour can play a substantial role (Camerer and Weber 2012).
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The Guardian recently published an article by Nakkiah Lui, a Gamillaroi and Torres Strait Islander woman and writer, titled “Why this year’s NAIDOC week will be my last”. In response, Dr Chelsea Bond, an Aboriginal (Munanjahli) and South Sea Islander Australian and a senior lecturer with the Aboriginal and Torres Strait Islander Studies Unit at the University of Queensland, explains why she will continue to celebrate NAIDOC Week – as an act of agency.
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The predicted secondary structure of sub-genomic RNA in dengue virus defective interfering (D.I.) particles from patients, or generated in vitro, resembled that of the 3′ and 5′ regions of wild type dengue virus (DENV) genomes. While these structures in the sub-genomic RNA were found to be essential for its replication, their nucleotide sequences were not, so long as any new sequences maintained wild type RNA secondary structure. These observations suggested that these sub-genomic fragments of RNA from dengue viruses were replicated in the same manner as the full length genomes of their wild type, “helper”, viruses and that they probably represent the smallest fragments of DENV RNA that can be replicated during a natural infection. While D.I. particles containing sub-genomic RNA are completely parasitic, the relationship between wild type and D.I. DENV may be symbiotic, with the D.I. particles enhancing the transmission of infectious DENV.
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The early years are significant in optimising children’s educational, emotional and social outcomes and have become a major international policy priority. Within Australia, policy levers have prioritised early childhood education, with a focus on program quality, as it is associated with lifelong success. Longitudinal studies have found that high quality teacher-child interactions are an essential element of high quality programs, and teacher questioning is one aspect of teacher-child interactions that has been attributed to affecting the quality of education, linking open ended questioning to higher cognitive achievement. Teachers, however, overwhelmingly ask more closed than open questions. In the classroom, like everyday interaction, questions in interaction require answers. They are used to request, offer, repair, challenge, seek agreement (Curl & Drew, 2008; Enfield, Stivers, & Levinson, 2010; Hayano, 2013; Schegloff, 2007). Teachers use questions to set agendas and manage lessons (McHoul, 1978; Mehan, 1979; Sacks, 1995), and to gauge students’ knowledge and understanding (Lerner, 1995; McHoul, 1978; Mehan, 1979). Drawing on data from the Australian Research Council project Interacting with Knowledge: Interacting with people: Web searching in early childhood, this paper focuses on an extended sequence of talk between a teacher with two students aged between 3.5 and 5 years in a preschool classroom. The episode, drawn from a corpus of over 200 hours of video recorded data, captures how the teacher and children undertake an online search for images of lady beetles and hairy caterpillars on the Web. Ethnomethodological and conversation analysis approaches examine how the teacher asks questions, which call on the children to display their factual knowledge about the search topic. The fine grained analysis shows how teachers design their interactions to prompt children’s displays of factual knowledge, and how the design of factual questions affect a student’s response in terms of what and how they respond. In focussing on how the teacher designs factual questions and how children respond to these questions it shows that question design can close down a student’s reply; or elicit a range of answers, from one word to extended more detailed responses. Understanding how the design of teachers’ questions can influence students’ responses has pedagogic implications and may support educators to make intentional decisions regarding their own questioning techniques.
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Explores how young people in Australia first come to inject drugs and how they learn about hepatitis C and sterile injecting drug use. Background on hepatitis C; Reasons for injecting drugs; Selection criteria for young people's participation in the i2i Project.
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This chapter is based on a qualitative case study that researched the perceptions of nine male and female pre-service English teachers’ in regards to their preparedness to mentor positive digital conduct in Social network sites (SNS). These sites enable individuals to perform public representations of identity, consumed by virtual audiences, with various degrees of perceived privacy. The chapter frames what we call “identity curation” through three theoretical lenses; of performativity, customisation and critical literacy. This chapter discusses one of the themes that emerged from the research, which is the way in which “normalised” and naturalised representations of femineity on SNS were judged more harshly than masculine representations.
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Osteogenesis imperfecta (OI) is a heritable disease occurring in one out of every 20,000 births. Although it is known that Type I collagen mutation in OI leads to increased bone fragility, the mechanism of this increased susceptibility to fracture is not clear. The aim of this study was to assess the microstructure of cortical bone fragments from patients with osteogenesis imperfecta (OI) using polarized light microscopy, and to correlate microstructural observations with the results of previously performed mechanical compression tests on bone from the same source. Specimens of cortical bone were harvested from the lower limbs of three (3) OI patients at the time of surgery, and were divided into two groups. Group 1 had been subjected to previous micro-mechanical compression testing, while Group 2 had not been subjected to any prior testing. Polarized light microscopy revealed disorganized bone collagen architecture as has been previously observed, as well as a large increase in the areal porosity of the bone compared to typical values for healthy cortical bone, with large (several hundred micron sized), asymmetrical pores. Importantly, the areal porosity of the OI bone samples in Group 1 appears to correlate strongly with their previously measured apparent Young's modulus and compressive strength. Taken together with prior nanoindentation studies on OI bone tissue, the results of this study suggest that increased intra-cortical porosity is responsible for the reduction in macroscopic mechanical properties of OI cortical bone, and therefore that in vivo imaging modalities with resolutions of ~ 100 μm or less could potentially be used to non-invasively assess bone strength in OI patients. Although the number of subjects in this study is small, these results highlight the importance of further studies in OI bone by groups with access to human OI tissue in order to clarify the relationship between increased porosity and reduced macroscopic mechanical integrity.
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The stoned locus in Drosophila encodes two proteins StonedA (STNA) and StonedB (STNB), both of which have been suggested to act as adaptins in mediating synaptic vesicle recycling. A combination of immunological, genetic and biochemical studies have shown an interaction of STNA and STNB with the C2B domain of Synaptotagmin-I (SYT-1), an integral synaptic vesicle protein that mediates Ca2+-dependent exocytosis, as well as endocytosis. The C2B domain of SYT-1 contains an AP-2 binding site that controls the size of recycled vesicles, and a C-terminal tryptophan-containing motif that acts as an internalization signal. Investigation of SYT-1 mutations in Drosophila has shown that altering the Ca2+ binding region of the C2B domain, results in a reduction in the rate of vesicle recycling, implicating this region in SYT-I endocytosis. In this poster, we report the molecular dissection of the interactions between the STNA and STNB proteins and the C2B domain of SYT-1. Deletion of the AP-2 binding site decreased the binding of both STNA and STNB. However, C-terminal deletions of the C2B domain significantly increased STNB binding. In contrast, the same C-terminal deletions reduced the affinity of the C2B domain for STNA. The possible interactions of both STNB and STNA with the Ca2+ binding region of SYT-1 will be also investigated.
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Surveys by PR-COM, a communications agency, indicate that leading German companies (1) have not recognized the relevance of social media yet or (2) have difficulties with implementing the concept (Meiners et al. 2010). For example, a survey among DAX-companies indicates that their social media activities are “lückenhaft und halbherzig” (PR-COM 2009). Another survey in the German IT industry shows that less than a third had a German and/or English blog (PR-COM 2010), even though blogging is considered a key tool for marketing communications. However, firms “that are not present on social media run the risk of not being in the position to build a positive reputation or to correct negative comments” (Meiners et al. 2010).