91 resultados para Chinese postman problem
Resumo:
PURPOSE AND METHOD: This questionnaire survey of 190 university music students assessed negative feelings of music performance anxiety (MPA) before performing, the experience of stage fright as a problem, and how closely they are associated with each other. The study further investigated whether the experience of stage fright as a problem and negative feelings of MPA predict the coping behavior of the music students. Rarely addressed coping issues were assessed, i.e., self-perceived effectiveness of different coping strategies, knowledge of possible risks and acceptance of substance-based coping strategies, and need for more support.RESULTS: The results show that one-third of the students experienced stage fright as a problem and that this was only moderately correlated with negative feelings of MPA. The experience of stage fright as a problem significantly predicted the frequency of use and the acceptance of medication as a coping strategy. Breathing exercises and self-control techniques were rated as effective as medication. Finally, students expressed a strong need to receive more support (65%) and more information (84%) concerning stage fright.CONCLUSION: Stage fright was experienced as a problem and perceived as having negative career consequences by a considerable percentage of the surveyed students. In addition to a desire for more help and support, the students expressed an openness and willingness to seriously discuss and address the topic of stage fright. This provides a necessary and promising basis for optimal career preparation and, hence, an opportunity to prevent occupational problems in professional musicians. [Authors]
Resumo:
A wide variety of whole cell bioreporter and biosensor assays for arsenic detection has been developed over the past decade. The assays permit flexible detection instrumentation while maintaining excellent method of detection limits in the environmentally relevant range of 10-50 μg arsenite per L and below. New emerging trends focus on genetic rewiring of reporter cells and/or integration into microdevices for more optimal detection. A number of case studies have shown realistic field applicability of bioreporter assays.
Resumo:
The hydrological and biogeochemical processes that operate in catchments influence the ecological quality of freshwater systems through delivery of fine sediment, nutrients and organic matter. Most models that seek to characterise the delivery of diffuse pollutants from land to water are reductionist. The multitude of processes that are parameterised in such models to ensure generic applicability make them complex and difficult to test on available data. Here, we outline an alternative - data-driven - inverse approach. We apply SCIMAP, a parsimonious risk based model that has an explicit treatment of hydrological connectivity. we take a Bayesian approach to the inverse problem of determining the risk that must be assigned to different land uses in a catchment in order to explain the spatial patterns of measured in-stream nutrient concentrations. We apply the model to identify the key sources of nitrogen (N) and phosphorus (P) diffuse pollution risk in eleven UK catchments covering a range of landscapes. The model results show that: 1) some land use generates a consistently high or low risk of diffuse nutrient pollution; but 2) the risks associated with different land uses vary both between catchments and between nutrients; and 3) that the dominant sources of P and N risk in the catchment are often a function of the spatial configuration of land uses. Taken on a case-by-case basis, this type of inverse approach may be used to help prioritise the focus of interventions to reduce diffuse pollution risk for freshwater ecosystems. (C) 2012 Elsevier B.V. All rights reserved.
Resumo:
Challenging the view of asymmetrical power relations between China and Africa, this thesis questions the "Chinese comparative advantages" (monolithic state power and economic advantages) of Chinese state-owned enterprises (SOEs) in Africa. It argues that the power dynamics between Chinese and African actors are dialectical and pluralistic, with localized social capital representing the true Chinese competitive advantage in Africa. Based on ethnographical fieldwork conducted in Ghana, this thesis shows that Chinese SOEs pursue their globalization in a double context - that of the deliberate "retreat" of the Chinese state, and more importantly, that of Ghanaian governance and society (characterized by political party patronage, extraversion dynamics, and worker agency). The trajectories of Chinese expatriates' expatriation/ social promotion and their SOEs' globalization/ localization are mutually influenced and reinforced. By cultivating local relationships and knowledge, a provincial Chinese SOE in Ghana can outperform a large Chinese central SOE, even if the latter has more support from the Chinese state. Moreover, the recent effort to build a "socially acceptable Chinese community" in Ghana has renewed the power dynamics between the Chinese state and the SOEs. All these observations provide for constructing a new perspective of Chinese SOEs in Africa - a "second-class" Chinese globalization - the SOEs may begin with few privileges, but promotion over time is possible. -- A contre pied des approches postulant des relations de pouvoir asymétriques entre la Chine et l'Afrique, cette thèse interroge les « avantages comparatifs chinois » (pouvoir de l'État monolithique et avantages économiques) des entreprises publiques chinoises (EPC) en Afrique. Elle soutient l'idée selon laquelle les dynamiques de pouvoir entre les acteurs chinois et africains est dialectique et pluraliste, et le capital social localisé étant le véritable avantage compétitif chinois en Afrique. S'appuyant sur un travail de terrain ethnographique au Ghana, cette thèse montre que les EPC poursuivent leur mondialisation dans un double contexte - celui de la «retraite» délibérée de l'État chinois, et, de façon plus importante, celui de la gouvernance et de la société ghanéennes (caractérisées par un clientélisme des partis politiques, une dynamique d'extraversion et le pouvoir de négociation des travailleurs). Les trajectoires d'expatriation / de promotion sociale des expatriés chinois et la mondialisation / localisation de leurs EPC s'influencent et se renforcent mutuellement. En cultivant des relations et des connaissances locales, une EPC provinciale au Ghana peut surpasser une grande EPC centrale, même si cette dernière reçoit plus de soutien de l'État chinois. En outre, les efforts récents visant à construire une «communauté chinoise socialement acceptable» au Ghana ont renouvelé la dynamique du pouvoir entre l'État chinois et les EPC. Ces observations permettent de construire une nouvelle perspective des EPC en Afrique - la globalisation chinoise de « deuxième classe » - les EPC peuvent débuter avec peu de privilèges, mais leur promotion reste possible avec le temps.
Resumo:
The reversal of congenital hypogonadotropic hypogonadism (CHH) is a relatively recent phenomenon that has gained increasing attention over the past 10 years. Yet to date, only one prospective study has been conducted estimating that 10% (95% confidence interval [CI]: 2%-18%) of cases undergo reversal. [1] Other retrospective studies have reported rates in the range of 5%-8% [2],[3] and a recent study showed 44/308 (14%, 95% CI: 11%-19%) CHH patients underwent reversal. [4] Moreover, a time-to-event analysis in this large cohort revealed a lifetime reversal incidence of 22%. The article by Mao and colleagues presented in this issue is a meaningful contribution to our understanding of reversal as it examines the largest retrospective cohort to date. [5] Interestingly, they report the rate of reversal as 5% (95% CI: 3%-8%) in this Chinese cohort. It is difficult to reconcile the discrepancies in rates of reversibility and direct comparisons are hampered by the variable definitions employed. Using a novel definition for reversal (i.e, either endogenous testosterone (T) >270 ng dl−1 , serum T gradually increasing above 150 ng dl−1 with increased testicular volume, or normal spontaneous sperm production/normal erectile function/ejaculation), Mao and colleagues posit that testicular size and triptorelin-stimulated LH levels are reliable predictive factors for reversal. However, these cannot be considered as hard and fast rules for predicting reversal as the groups intersect - akin to the overlap observed between CHH patients and those with delayed puberty. Indeed, the fact that approximately half (44%, 95% CI: 25%-66%) of the reversal patients in the study by Mao et al.[5] were diagnosed between 17 and 19 years of age, underscores the challenge in differentiating CHH from extreme normal variants of puberty. This study further lends credence the recently reported observations that reversals may relapse. [4],[6] The notion that reversal may not be lasting highlights the vulnerability of the reproductive axis among CHH patients. While the mechanism(s) for relapse are unclear, it seems plausible that environmental, metabolic or psychiatric stressors could contribute. The factors that Mao and colleagues identify as significantly different in cases of reversal, were not informative for identifying those cases that relapsed back to a hypogonadal state. Notably, reversal has been reported in probands harboring mutations in genes underlying CHH. [1],[3],[4],[6] Unfortunately, comprehensive genetic screening on the Chinese cohort is not available. The reversal phenomenon is fascinating for its glimpse into the plasticity of the neuroendocrine control of reproduction. Future directions will almost certainly include investigation of specific genetic signatures and novel biomarkers for predicting reversal (and relapse). Yet CHH is a rare condition and to fully elucidate the biology of reversible CHH, it will be important to harmonize definitions of what constitutes a reversal, carefully phenotype patients and chart the natural history of their CHH. In this way, this unique human disease model may offer further insights into the control of human reproduction and provide opportunities to translate discoveries into enhanced approaches to improve the care and quality of life for these patients.
Resumo:
The interpretation of fingerprint evidence depends on the judgments of fingerprint examiners. This study assessed the accuracy of different judgments made by fingerprint examiners following the Analysis, Comparison, and Evaluation (ACE) process. Each examiner was given five marks for analysis, comparison, and evaluation. We compared the experts' judgments against the ground truth and used an annotation platform to evaluate how Chinese fingerprint examiners document their comparisons during the identification process. The results showed that different examiners demonstrated different accuracy of judgments and different mechanisms to reach them.