989 resultados para 146-891
Resumo:
Concurrent and longitudinal links between children’s own and their nominated best friends’ antisocial and prosocial behavior were studied in a normative sample of 3–5-year-olds (N = 203). Moderating effects of age and gender were also explored. Subscales of the Strength and Difficulties Questionnaire (SDQ) were used to obtain teacher ratings of behavior for each target child and his/her nominated best friends. Nomination of best friends with higher levels of antisocial behavior and lower levels of prosocial behavior was concurrently linked to more antisocial behavior in boys. Nomination of highly prosocial best friends was concurrently linked to more prosocial behavior in both boys and girls. However, the study found no longitudinal effects of best friends’ behavior on target child’s behavior over a one-year period. A group of children who nominated no best friends at T1 were generally perceived as less prosocial, but not more antisocial, than other children. © 2011 Elsevier Inc. All rights reserved.
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This paper examines the case of a procurement auction for a single project, in which the breakdown of the winning bid into its component items determines the value of payments subsequently made to bidder as the work progresses. Unbalanced bidding, or bid skewing, involves the uneven distribution of mark-up among the component items in such a way as to attempt to derive increased benefit to the unbalancer but without involving any change in the total bid. One form of unbalanced bidding for example, termed Front Loading (FL), is thought to be widespread in practice. This involves overpricing the work items that occur early in the project and underpricing the work items that occur later in the project in order to enhance the bidder's cash flow. Naturally, auctioners attempt to protect themselves from the effects of unbalancing—typically reserving the right to reject a bid that has been detected as unbalanced. As a result, models have been developed to both unbalance bids and detect unbalanced bids but virtually nothing is known of their use, success or otherwise. This is of particular concern for the detection methods as, without testing, there is no way of knowing the extent to which unbalanced bids are remaining undetected or balanced bids are being falsely detected as unbalanced. This paper reports on a simulation study aimed at demonstrating the likely effects of unbalanced bid detection models in a deterministic environment involving FL unbalancing in a Texas DOT detection setting, in which bids are deemed to be unbalanced if an item exceeds a maximum (or fails to reach a minimum) ‘cut-off’ value determined by the Texas method. A proportion of bids are automatically and maximally unbalanced over a long series of simulated contract projects and the profits and detection rates of both the balancers and unbalancers are compared. The results show that, as expected, the balanced bids are often incorrectly detected as unbalanced, with the rate of (mis)detection increasing with the proportion of FL bidders in the auction. It is also shown that, while the profit for balanced bidders remains the same irrespective of the number of FL bidders involved, the FL bidder's profit increases with the greater proportion of FL bidders present in the auction. Sensitivity tests show the results to be generally robust, with (mis)detection rates increasing further when there are fewer bidders in the auction and when more data are averaged to determine the baseline value, but being smaller or larger with increased cut-off values and increased cost and estimate variability depending on the number of FL bidders involved. The FL bidder's expected benefit from unbalancing, on the other hand, increases, when there are fewer bidders in the auction. It also increases when the cut-off rate and discount rate is increased, when there is less variability in the costs and their estimates, and when less data are used in setting the baseline values.
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Ghrelin, the endogenous ligand for the GH secretagogue receptor (GHSR), is a peptide hormone with diverse physiological roles. Ghrelin regulates GH release, appetite and feeding, gut motility, and energy balance and also has roles in the cardiovascular, immune, and reproductive systems. Ghrelin and the GHSR are expressed in a wide range of normal and tumor tissues, and a fluorescein-labeled, truncated form of ghrelin is showing promise as a biomarker for prostate cancer. Plasma ghrelin levels are generally inversely related to body mass index and are unlikely to be useful as a biomarker for cancer, but may be useful as a marker for cancer cachexia. Some single nucleotide polymorphisms in the ghrelin and GHSR genes have shown associations with cancer risk; however, larger studies are required. Ghrelin regulates processes associated with cancer, including cell proliferation, apoptosis, cell migration, cell invasion, inflammation, and angiogenesis; however, the role of ghrelin in cancer is currently unclear. Ghrelin has predominantly antiinflammatory effects and may play a role in protecting against cancer-related inflammation. Ghrelin and its analogs show promise as treatments for cancer-related cachexia. Further studies using in vivo models are required to determine whether ghrelin has a role in cancer progression.
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Superconducting Bi-2212 tapes and laminates are fabricated by a combination of dip-coating and partial melt processing. The heat treated tapes have critical current densities (Jc) up to 11 kAcm -2. We investigate the degradation of critical current (Ic) during bending experiments for both single tapes and tapes with laminate structure. Although degradation of Ic is observed in both forms, the characteristics of the degradation differ. It is determined that laminated tapes perform better than single tapes when critical current is measured against bending radius, and laminated tapes tolerate a higher strain for a given reduction in critical current. It is found that increasing the number of Bi-2212 layers increases the total Ic of the laminated tape, but degradation of critical current is more pronounced during bending because of the increased total thickness of the laminate structure. It is also found that addition of silver to the Bi-2212 layers reduces critical current degradation during bending for both tapes and laminates.
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Whole-body computer control interfaces present new opportunities to engage children with games for learning. Stomp is a suite of educational games that use such a technology, allowing young children to use their whole body to interact with a digital environment projected on the floor. To maximise the effectiveness of this technology, tenets of self-determination theory (SDT) are applied to the design of Stomp experiences. By meeting user needs for competence, autonomy, and relatedness our aim is to increase children's engagement with the Stomp learning platform. Analysis of Stomp's design suggests that these tenets are met. Observations from a case study of Stomp being used by young children show that they were highly engaged and motivated by Stomp. This analysis demonstrates that continued application of SDT to Stomp will further enhance user engagement. It also is suggested that SDT, when applied more widely to other whole-body multi-user interfaces, could instil similar positive effects.
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The aim of this paper is to examine the association between a range of objectively measured neighbourhood features and the likelihood of mid-aged adults walking for transport. Increased walking for transport would bring multiple benefits, including improved population and environmental health. As part of the baseline HABITAT study, 10,745 residents of Brisbane, Australia, aged 40–65 years, from 200 neighbourhoods were asked about the time they spent walking for transport. Walking data were collected by mail survey and the physical environmental features of neighbourhoods were compiled using a geographic information systems database. Walking for transport was categorised into four levels and the association between walking and each neighbourhood characteristic was examined using multilevel multinomial models. A number of threshold trends were evident; for example, off-road bikeways were consistently associated with walking between 60 and 150 min per week. Living within 500 m of public transit was also an important predictor but only for those who walked for less than 150 min per week. Interventions targeting these neighbourhood characteristics may lead to improved environmental quality, lower rates of overweight and obesity and associated chromic disease.
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We focus on understanding the role of productivity in determining wage structure differences between men and women in academia. The data arise from a pay-equity study carried out in a single Midwestern U.S. university over the 1996–7 academic year. Econometric results confirm that external market forces exert influence over both male and female salary. But peer review ratings play a significant role in male but not female earnings determination, with similar results for objective measures of research, teaching and service.
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Aim. To develop and evaluate the implementation of a communication board for paramedics to use with patients as an augmentative or alternative communication tool to address communication needs of patients in the pre-hospital setting. Method. A double-sided A4-size communication board was designed specifically for use in the pre-hospital setting by the Queensland Ambulance Service and Disability and Community Care Services. One side of the board contains expressive messages that could be used by both the patient and paramedic. The other side contains messages to support patients’ understanding and interaction tips for the paramedic. The communication board was made available in every ambulance and patient transport vehicle in the Brisbane Region. Results. A total of 878 paramedics completed a survey that gauged which patient groups they might use the communication board with. The two most common groups were patients from culturally and linguistically diverse backgrounds and children. Staff reported feeling confident in using the board, and 72% of interviewed paramedics agreed that the communication board was useful for aiding communication with patients. Feedback from paramedics suggests that the board is simple to use, reduces patient frustration and improves communication. Conclusion. These results suggest that a communication board can be applied in the pre-hospital setting to support communication success with patients. What is known about the topic? It is imperative that communication between patient and paramedic is clear and effective. Research has shown that communication boards have been effective with people with temporary or permanent communication difficulties. What does this paper add? This is the first paper outlining the development and use of a communication board by paramedics in the pre-hospital setting in Australia. The paper details the design of the communication board for the unique pre-hospital environment. The paper provides some preliminary data on the use of the communication board with certain patient groups and its effectiveness as an alternative communication tool. What are the implications for practitioners? The findings support the use of the tool as a viable option in supporting the communication between paramedics and a range of patients. It is not suggested that this communication board will meet the complete communication needs of any individual in this environment, but it is hoped that the board’s presence within the Queensland Ambulance Service may result in paramedics introducing the board on occasions where communication with a patient is challenging.
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Entity-oriented retrieval aims to return a list of relevant entities rather than documents to provide exact answers for user queries. The nature of entity-oriented retrieval requires identifying the semantic intent of user queries, i.e., understanding the semantic role of query terms and determining the semantic categories which indicate the class of target entities. Existing methods are not able to exploit the semantic intent by capturing the semantic relationship between terms in a query and in a document that contains entity related information. To improve the understanding of the semantic intent of user queries, we propose concept-based retrieval method that not only automatically identifies the semantic intent of user queries, i.e., Intent Type and Intent Modifier but introduces concepts represented by Wikipedia articles to user queries. We evaluate our proposed method on entity profile documents annotated by concepts from Wikipedia category and list structure. Empirical analysis reveals that the proposed method outperforms several state-of-the-art approaches.
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Post-transplantation lymphoproliferative disorders (PTLD) arise in the immunosuppressed and are frequently Epstein-Barr virus (EBV) associated. The most common PTLD histological sub-type is diffuse large B-cell lymphoma (EBV+DLBCL-PTLD). Restoration of EBV-specific T-cell immunity can induce EBV+DLBCL-PTLD regression. The most frequent B-cell lymphoma in the immunocompetent is also DLBCL. ‘EBV-positive DLBCL of the elderly’ (EBV+DLBCL) is a rare but well-recognized DLBCL entity that occurs in the overtly immunocompetent, that has an adverse outcome relative to EBV-negative DLBCL. Unlike PTLD (which is classified as viral latency III), literature suggests EBV+DLBCL is typically latency II, i.e. expression is limited to the immuno-subdominant EBNA1, LMP1 and LMP2 EBV-proteins. If correct, this would be a major impediment for T-cell immunotherapeutic strategies. Unexpectedly we observed EBV+DLBCL-PTLD and EBV+DLBCL both shared features consistent with type III EBV-latency, including expression of the immuno-dominant EBNA3A protein. Extensive analysis showed frequent polymorphisms in EBNA1 and LMP1 functionally defined CD8+ T-cell epitope encoding regions, whereas EBNA3A polymorphisms were very rare making this an attractive immunotherapy target. As with EBV+DLBCL-PTLD, the antigen presenting machinery within lymphomatous nodes was intact. EBV+DLBCL express EBNA3A suggesting it is amenable to immunotherapeutic strategies.
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Objective To evaluate the effectiveness of the 7-valent pneumococcal conjugate vaccine (PCV7) in preventing pneumonia, diagnosed radiologically according to World Health Organization (WHO) criteria, among indigenous infants in the Northern Territory of Australia. Methods We conducted a historical cohort study of consecutive indigenous birth cohorts between 1 April 1998 and 28 February 2005. Children were followed up to 18 months of age. The PCV7 programme commenced on 1 June 2001. All chest X-rays taken within 3 days of any hospitalization were assessed. The primary endpoint was a first episode of WHO-defined pneumonia requiring hospitalization. Cox proportional hazards models were used to compare disease incidence. Findings There were 526 pneumonia events among 10 600 children - an incidence of 3.3 per 1000 child-months; 183 episodes (34.8%) occurred before 5 months of age and 247 (47.0%) by 7 months. Of the children studied, 27% had received 3 doses of vaccine by 7 months of age. Hazard ratios for endpoint pneumonia were 1.01 for 1 versus 0 doses; 1.03 for 2 versus 0 doses; and 0.84 for 3 versus 0 doses. Conclusion There was limited evidence that PCV7 reduced the incidence of radiologically confirmed pneumonia among Northern Territory indigenous infants, although there was a non-significant trend towards an effect after receipt of the third dose. These findings might be explained by lack of timely vaccination and/or occurrence of disease at an early age. Additionally, the relative contribution of vaccine-type pneumococcus to severe pneumonia in a setting where multiple other pathogens are prevalent may differ with respect to other settings where vaccine efficacy has been clearly established.
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RNA-mediated silencing in plants can spread from cell to cell and over a long distance, and such mobile silencing has been extensively studied in the past decade. However, major questions remain as to what is the exact nature of the mobile silencing signals, how the components of the RNA-directed DNA methylation pathway are involved, and why systemic spread of silencing has only been observed for transgenes but not endogenous genes. In this review, we provide an overview of the current knowledge on mobile gene silencing in plants and present a model where systemic silencing involves long nuclear RNA transcripts that serve as a template to amplify primary siRNA signals.