232 research outputs found

    Transfer of academic staff learning in a research-intensive university

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    In both Australia and abroad, there is an increasing pressure towards professionalisation of university teaching, with the expectation that academic development courses, such as the Graduate Certificate in Education Studies (higher education), lead to better teaching and learning practices. However, the knowledge, skills and/or attitudes that educators intend students to learn may not transfer successfully back to the workplace. This may occur for a variety of reasons, including individual characteristics of the learner (e.g. ability, motivation), and situational characteristics (e.g. the climate for transfer, including adequacy of resources and peer/manager support). The present study investigates the impact of these factors on teaching staff in a research-intensive university. Two in-depth case studies, followed by thematic analysis of 15 Graduate Certificate alumni interviews regarding post-course experiences, revealed that qualities of the work environment played significant roles in interviewees’ postcourse attitudes, intentions and activities related to the transfer of learning. Implications for encouraging transfer under similar circumstances are discussed.postprin

    Adrenalectomy-Produced Facilitation of Pavlovian Conditioned Cardiodecelerations in Immobilized Rats

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    Previous evidence has suggested that both hormonal and behavioral aspects of adrenal stress activation may contribute to heart rate (HR) conditioning during physical/pharmacological immobilization. Accordingly, four studies were conducted to determine if bilateral adrenalectomy facilitates stimulus-control over Pavlovian conditioned cardiodecelerations in rats immobilized either through physical restraint or neuromuscular paralysis. Plasma corticosterone assays were used as an index of the effectiveness of adrenal removal. The results showed that adrenalectomy facilitated both simple and discriminated Pavlovian conditioned cardiodecelerations in rats paralyzed with d-tubocurarine chloride (dTC) without significantly altering the characteristics of EMG recovery from paralysis. Similarly, adrenalectomy facilitated simple Pavlovian HR conditioning in physically restrained rats. The results suggest that adrenal activation may disrupt the parasympathetically-mediated Pavlovian conditioned cardiodeceleration in the physically-and dTC-immobilized rat. However, the specific nature of neuroendocrine mechanisms underlying cardiovascular conditioning during immobilization remains problematical.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75069/1/j.1469-8986.1977.tb03371.x.pd

    Stress and estrous cycle affect strategy but not performance of female C57BL/6J mice

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    Stress induces a switch in learning strategies of male C57BL/6J mice from predominantly spatial to more stimulus-response learning. To study generalization of these findings over sex, we investigated female C57BL/6J mice at three phases of the estrous cycle under non stress and acute (10 min) restraint stress conditions. On a circular hole board (CHB) task, about half of the naive female mice used spatial and stimulus-response strategies to solve the task. Under stress, female mice favored spatial over stimulus-response strategies, with 100% of female mice in the estrus phase. Performance expressed as latency to solve the task is only improved in stressed female mice in the estrus phase. We conclude that the use of learning strategies is influenced by sex and this difference between sexes is aggravated by acute stress

    Cortisol secretion after adrenocorticotrophin (ACTH) and Dexamethasone tests in healthy female and male dogs

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    <p>Abstract</p> <p>Background</p> <p>For the conclusive diagnosis of Cushing's Syndrome, a stimulating ACTH test or a low suppressive Dexamethasone test is used. Reports in other species than the dog indicate that plasma cortisol concentration after ACTH administration is affected by gender. We investigated the effect of gender on the cortisol response to ACTH and Dexamethasone tests in dogs.</p> <p>Methods</p> <p>Seven healthy adult Cocker Spaniels (4 females and 3 males) were assigned to a two by two factorial design: 4 dogs (2 females and 2 males) received IV Dexamethasone 0.01 mg/kg, while the other 3 dogs received an IV saline solution (control group). Two weeks later the treatments were reversed. After one month, ACTH was given IV (250 μg/animal) to 4 dogs (2 female and 2 males) while the rest was treated with saline solution (control group). Cortisol concentrations were determined by a direct solid-phase radioimmunoassay and cholesterol and triglycerides by commercial kits.</p> <p>Results and Discussion</p> <p>No effect of treatment was observed in metabolite concentrations, but females presented higher cholesterol concentrations. ACTH-treated dogs showed an increase in cortisol levels in the first hour after sampling until 3 hours post injection. Cortisol concentrations in Dexamethasone-treated dogs decreased one hour post injection and remained low for 3 hours, thereafter cortisol concentrations increased. The increase in cortisol levels from one to two hours post ACTH injection was significantly higher in females than males. In Dexamethasone-treated males cortisol levels decreased one hour post injection up to 3 hours; in females the decrease was more pronounced and prolonged, up to 5 hours post injection.</p> <p>Conclusion</p> <p>We have demonstrated that cortisol response to ACTH and Dexamethasone treatment in dogs differs according to sex.</p

    The role of melatonin in the pathogenesis of adolescent idiopathic scoliosis (AIS)

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    The cause of adolescent idiopathic scoliosis (AIS) in humans remains obscure and probably multifactorial. At present, there is no proven method or test available to identify children or adolescent at risk of developing AIS or identify which of the affected individuals are at risk of progression. Reported associations are linked in pathogenesis rather than etiologic factors. Melatonin may play a role in the pathogenesis of scoliosis (neuroendocrine hypothesis), but at present, the data available cannot clearly show the role of melatonin in producing scoliosis in humans. The data regarding human melatonin levels are mixed at best, and the melatonin deficiency as a causative factor in the etiology of scoliosis cannot be supported. It will be an important issue of future research to investigate the role of melatonin in human biology, the clinical efficacy, and safety of melatonin under different pathological situations. Research is needed to better define the role of all factors in AIS development

    Relevance of Stress and Female Sex Hormones for Emotion and Cognition

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    There are clear sex differences in incidence and onset of stress-related and other psychiatric disorders in humans. Yet, rodent models for psychiatric disorders are predominantly based on male animals. The strongest argument for not using female rodents is their estrous cycle and the fluctuating sex hormones per phase which multiplies the number of animals to be tested. Here, we will discuss studies focused on sex differences in emotionality and cognitive abilities in experimental conditions with and without stress. First, female sex hormones such as estrogens and progesterone affect emotions and cognition, contributing to sex differences in behavior. Second, females respond differently to stress than males which might be related to the phase of the estrous cycle. For example, female rats and mice express less anxiety than males in a novel environment. Proestrus females are less anxious than females in the other estrous phases. Third, males perform in spatial tasks superior to females. However, while stress impairs spatial memory in males, females improve their spatial abilities, depending on the task and kind of stressor. We conclude that the differences in emotion, cognition and responses to stress between males and females over the different phases of the estrous cycle should be used in animal models for stress-related psychiatric disorders

    A rise in NAD precursor nicotinamide mononucleotide (NMN) after injury promotes axon degeneration.

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    NAD metabolism regulates diverse biological processes, including ageing, circadian rhythm and axon survival. Axons depend on the activity of the central enzyme in NAD biosynthesis, nicotinamide mononucleotide adenylyltransferase 2 (NMNAT2), for their maintenance and degenerate rapidly when this activity is lost. However, whether axon survival is regulated by the supply of NAD or by another action of this enzyme remains unclear. Here we show that the nucleotide precursor of NAD, nicotinamide mononucleotide (NMN), accumulates after nerve injury and promotes axon degeneration. Inhibitors of NMN-synthesising enzyme NAMPT confer robust morphological and functional protection of injured axons and synapses despite lowering NAD. Exogenous NMN abolishes this protection, suggesting that NMN accumulation within axons after NMNAT2 degradation could promote degeneration. Ectopic expression of NMN deamidase, a bacterial NMN-scavenging enzyme, prolongs survival of injured axons, providing genetic evidence to support such a mechanism. NMN rises prior to degeneration and both the NAMPT inhibitor FK866 and the axon protective protein Wld(S) prevent this rise. These data indicate that the mechanism by which NMNAT and the related Wld(S) protein promote axon survival is by limiting NMN accumulation. They indicate a novel physiological function for NMN in mammals and reveal an unexpected link between new strategies for cancer chemotherapy and the treatment of axonopathies

    Bolivian Marmosops

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    40 p. : ill., maps ; 26 cm.Electronic version available in portable document format (PDF).Includes bibliographical references (p. 34-37).In order to facilitate much-needed revisionary research on Marmosops, we summarize the currently accepted species-level taxonomy, provide full bibliographic citations for original descriptions of all 36 included nominal taxa, map their type localities, and list their type material (if known). We rediagnose the genus Marmosops, compare it with three other didelphid genera to which misidentified specimens of Marmosops have often been referred, and review the phylogenetic evidence that Marmosops is monophyletic. After describing a new species from the eastern-slope montane forests of Bolivia, we review the taxonomy of other Bolivian congeners based on morphological characters and published cytochrome-b gene sequences. Among our taxonomic results, we synonymize albiventris Tate (1931), dorothea Thomas (1911), and yungasensis Tate (1931) with M. noctivagus (Tschudi, 1845). By contrast, M. ocellatus (Tate, 1931), currently considered a synonym of dorothea, appears to be a valid species. Whereas published range maps of Bolivian species of Marmosops are demonstrably based on misidentified material and show little correspondence with known environmental factors, locality records based on specimens examined for this report make much more ecogeographic sense

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