993 resultados para 235


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A rule of thumb is suggested for comparing multinomial logit coefficients with multinomial probit coefficients in the special case where the normal errors are distributed N(0,1). The rule is a generalization of the '1.6' rule for comparing logit and probit coefficients. © 1989.

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Composite polymer insulators provide many advantages over the traditional porcelain insulators and they are increasingly being used at both transmission and distribution levels. In the present paper, an epoxy resin/silica nanocomposite dielectric material (NDM) structure is proposed and fabricated. Hydrophobic fumed silica is incorporated in epoxy resin matrix and acetone is adopted as media agent to effectively achieve homogenous dispersion of the nano-scale silica filler. The acetone also acts as diluents to reduce viscosity before the curing phase of epoxy resin and enables bubbles to escape from being trapped. Through partial discharge (PD) and surface aging tests, it is illustrated that the inception of surface discharge of the proposed NDM is relatively higher than that of the non-filled counterpart, and a better PD resistivity was observed in the negative half cycle regarding to applied AC voltage. Results of surface aging test indicate that surface discharge activity is retarded over the test conducting time. By contrast, surface discharge developed to the opposite way on the non-filled sample. Therefore, the proposed NDM could provide better safety reliability and lower maintenance cost to industrial application compared with nonfilled conventional epoxy resin.

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In contrast to extensive studies on familial breast cancer, it is currently unclear whether defects in DNA double strand break (DSB) repair genes play a role in sporadic breast cancer development and progression. We performed analysis of immunohistochemistry in an independent cohort of 235 were sporadic breast tumours. This analysis suggested that RAD51 expression is increased during breast cancer progression and metastasis and an oncogenic role for RAD51 when deregulated. Subsequent knockdown of RAD51 repressed cancer cell migration in vitro and reduced primary tumor growth in a syngeneic mouse model in vivo. Loss of RAD51 also inhibited associated metastasis not only in syngeneic mice but human xenografts and changed the metastatic gene expression profile of cancer cells, consistent with inhibition of distant metastasis. This demonstrates for the first time a new function of RAD51 that may underlie the proclivity of patients with RAD51 overexpression to develop distant metastasis. RAD51 is a potential biomarker and attractive drug target for metastatic triple negative breast cancer, with the capability to extend the survival of patients, which is less than 6 months.

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This commentary draws out themes from the narrative symposium on “living with the label “disability”” from the perspective of auto/biography and critical disability studies in the humanities. It notes the disconnect between the experiences discussed in the stories and the preoccupations of bioethicists. Referencing Rosemarie Garland-Thompson’s recent work, it suggests that life stories by people usually described as “disabled” offer narrative, epistemic and ethical resources for bioethics. The commentary suggests that the symposium offers valuable conceptual tools and critiques of taken-for-granted terms like “dependency”. It notes that these narrators do not un–problematically embrace the term “disability”, but emphasize the need to redefine, strategically deploy or reject this term. Some accounts are explicitly critical of medical practitioners while others redefine health and wellbeing, emphasizing the need for reciprocity and respect for the knowledge of people with disability, including knowledge from their experience of “the variant body” (Leach Scully, 2008).

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Desalination is considered one of the most suitable areas for the utilization of solar energy, as there are many places in the world where abundant supply of solar energy is available and also there is a great demand for fresh water. An integrated solar heat pump desalination system has been developed at the National University of Singapore. The system also offers the opportunity of water heating and drying utilizing solar, ambient energy and waste heat from air conditioning system, which is conventionally dumped into the environment causing global warming. Desalination is carried out by making use of a single effect of Multi-Effect Distillation (MED) system. Within the desalination chamber, both fl ashing and evaporation of saline water take place. The maximum Coefficient of Performance (COP) of the heat pump system was around 5.8. In the integrated system, the maximum fresh water production rate was 9.6 l h−1 and a Performance Ratio (PR) of 1.2. For only desalination, the system has the potential to produce a maximum of 30 l h−1 of fresh water.

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Aims The functional BDNF single nucleotide polymorphism (SNP) rs6265 has been associated with many disorders including schizophrenia and alcohol dependence. However, studies have been inconsistent, reporting both positive and negative associations. Comorbid alcohol dependence has a high prevalence in schizophrenia so we investigated the role of rs6265 in alcohol dependence in Australian populations of schizophrenia and alcohol dependent patients. Methods Two BDNF SNPs rs6265 and a nearby SNP rs7103411 were genotyped in a total of 848 individuals. These included a schizophrenia group (n = 157) and a second schizophrenia replication group (n = 235), an alcohol dependent group (n = 231) that had no schizophrenia diagnosis and a group of healthy controls (n = 225). Results Allelic association between rs7103411 and comorbid alcohol dependence was identified (P = 0.044) in the primary schizophrenia sample. In the replication study, we were able to detect allelic associations between both BDNF SNPs and comorbid alcohol dependence (rs6265, P = 0.006; rs7103411, P = 0.014). Moreover, we detected association between both SNPs and risk-taking behaviour after drinking (rs6265, P = 0.005; rs7103411, P = 0.009) and we detected strong association between both SNPs and alcohol dependence in males (rs6265, P = 0.009; rs7103411, P = 0.013) while females showed association with multiple behavioural measures reflecting repetitive alcohol consumption. Haplotype analysis revealed the rs6265-rs7103411 A/C haplotype is associated with comorbid alcohol dependence (P = 0.002). When these SNPs were tested in the non-schizophrenia alcohol dependent group we were unable to detect association. Conclusion We conclude that these BDNF SNPs play a role in development of comorbid alcohol dependence in schizophrenia while our data does not indicate that they play a role in alcohol dependent patients who do not have schizophrenia.

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The adoption of packaged software is becoming increasingly common in a variety of organizations and much of the packaged software literature presents this as a straightforward, linear process based on rationalistic evaluation. This paper applies the framework of power relations developed by Markus and Bjørn-­‐Anderson (1987) to a longitudinal study concerning the adoption of a customer relationship management package in a small organization. This is used to highlight both overt and covert power issues within the selection and procurement of the product and illustrate the interplay of power between senior management, IT managers, IT vendors and consultants, and end-­‐users. The paper contributes to the growing body of literature on packaged software and also to our understanding of how power is deeply embedded within the surrounding processes.

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A field oriented control (FOC) algorithm is simulated and implemented for use with a permanent magnet synchronous motor (PMSM). Rotor position is sensed using Hall effect switches on the stator because other hardware position sensors attached to the rotor may not be desirable or cost effective for certain applications. This places a limit on the resolution of position sensing – only a few Hall effect switches can be placed. In this simulation, three sensors are used and the position information is obtained at higher resolution by estimating it from the rotor dynamics, as shown in literature previously. This study compares the performance of the method with an incremental encoder using simulations. The FOC algorithm is implemented using Digital Motor Control (DMC) and IQ Texas Instruments libraries from a Simulink toolbox called Embedded Coder, and downloaded into a TI microcontroller (TMS320F28335) known as the Piccolo via Code Composer Studio (CCS).

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This paper presents a discussion on the use of MIMO and SISO techniques for identification of the radiation force terms in models for surface vessels. We compare and discuss two techniques recently proposed in literature for this application: time domain identification and frequency domain identification. We compare the methods in terms of estimates model order, accuracy of the fit, use of the available information, and ease of use and implementation.

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The nature of construction projects and their delivery exposes participants to accidents and dangers. Safety climate serves as a frame of reference for employees to make sense of safety measures in the workplace and adapt their behaviors. Though safety climate research abounds, fewer efforts are made to investigate the formation of a safety climate. An effort to explore forming psychological safety climate, an operationalization of safety climate at the individual level, is an appropriate starting point. Taking the view that projects are social processes, this paper develops a conceptual framework of forming the psychological safety climate, and provides a preliminary validation. The model suggests that management can create the desired psychological safety climate by efforts from structural, perceptual, interactive, and cultural perspectives. Future empirical research can be built on the model to provide a more comprehensive and coherent picture of the determinants of safety climate.

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The foraging behavior of greater short-nosed fruit bats (Cynopterus sphinx) on wild banana (Musa acuminata) and subsequent dispersal of seeds were studied in the Tropical Rainforest Conservation Area, Xishuangbanna Tropical Botanical Garden, Yunnan province, by direct observation of marked fruits, mist netting, and seed collection. The mean number (± SE) of individual C. sphinx captured by mist net were 2.2 ± 0.33/day and 1.4 ± 0.32/day in the rainy season (September to October) and dry season (November to December), respectively; the difference was not significant. The number of seed pellets expelled was 9.0 ± 1.12/day and 7.2 ± 1.37/day in the rainy and dry seasons respectively; again the difference was not significant. The removal curves for marked fruit were similar for 10 focal trees. Fruits were consumed heavily within two weeks after ripening and all the marked fruit were removed within one month. The difference in seed dispersal was significant between different feeding roosts indicating that patterns of seed dispersal may not be uniform. We found the seeds of M. acuminata can be dispersed by C. sphinx to a distance of about 200 m, and C. sphinx can be considered as an effective seed disperser of M. acuminata.

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Objective: This study investigated the influence of injury cause, contact-sport participation, and prior knowledge of mild traumatic brain injury (mTBI) on injury beliefs and chronic symptom expectations of mTBI. Method: A total of 185 non-contact-sport players (non-CSPs) and 59 contact-sport players (CSPs) with no history of mTBI were randomly allocated to one of two conditions in which they read either a vignette depicting a sport-related mTBI (mTBIsport) or a motor-vehicle-accident-related mTBI (mTBIMVA). The vignettes were otherwise standardized to convey the same injury parameters (e.g., duration of loss of consciousness). After reading a vignette, participants reported their injury beliefs (i.e., perceptions of injury undesirability, chronicity, and consequences) and their expectations of chronic postconcussion syndrome (PCS) and posttraumatic stress disorder (PTSD) symptoms. Results: Non-CSPs held significantly more negative beliefs and expected greater PTSD symptomatology and greater PCS affective symptomatology from an mTBIMVA vignette thann mTBIsport vignette, but this difference was not found for CSPs. Unlike CSPs, non-CSPs who personally knew someone who had sustained an mTBI expected significantly less PCS symptomatology than those who did not. Despite these different results for non-CSPs and CSPs, overall, contact-sport participation did not significantly affect injury beliefs and symptom expectations from an mTBIsport. Conclusions: Expectations of persistent problems after an mTBI are influenced by factors such as injury cause even when injury parameters are held constant. Personal knowledge of mTBI, but not contact sport participation, may account for some variability in mTBI beliefs and expectations. These factors require consideration when assessing mTBI outcome.

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Objective: This study assessed 12-month service use patterns among people with psychotic disorders and sought to identify determinants of service use. Methods: As part of a large two-phase Australian study of psychotic disorders, structured interviews were conducted with a stratified random sample of adults who screened positive for psychosis. Demographic characteristics, social functioning, symptoms, mental health diagnoses, and use of psychiatric and nonpsychiatric services were assessed. Data were analyzed for 858 persons who had an ICD-10 diagnosis of a psychotic disorder and who had been hospitalized for less than six months during the previous year. Results: People with psychotic disorders had high levels of use of health services, both in absolute terms and relative to people with nonpsychotic disorders. Those with psychotic disorders were estimated to have an average of one contact with health services per week. Use of psychiatric inpatient services was associated with parenthood, higher symptom levels, recent attempts at suicide or self-harm, personal disability, medication status, and frequency of alcohol consumption. Services provided by general practitioners (family physicians) were more likely to be obtained by older people, women, people with greater availability of friends, those with fewer negative symptoms, and those whose service needs were unmet by other sources. People who were high users of health services also reported having more contact with a range of non-health agencies. Conclusions: The predictors of service use accounted for small proportions of the variance in overall use of health services. The role of general practitioners in providing and monitoring treatment programs and other psychosocial interventions needs to be acknowledged and enhanced.

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The last two decades has seen a proliferation in the provision of, and importance attached to, coach education in many Western countries [1]. Pivotal to many coach education programmes is the notion of apprenticeship [2,3,4]. Increasingly, mentoring is being positioned as a possible tool for enhancing coach education and consequently professional expertise [5]. However, there is a paucity of empirical data on interventions in, and evaluations of, coach education programmes. In their recent evaluation of a coach education programme Cassidy, Potrac & McKenzie [6] conclude that the situated learning literature could provide coach educators with a generative platform for the (re)examinationof apprenticeships and mentoring in a coach education context. This paper consequently discusses the merits of using situated learning theory [7] and the associated concept of Communities of Practice (CoP) [8] to stimulate discussion on developing new understandings of the practices of apprenticeship and mentoring in coach education.