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191.
In this paper, optimal designs will be derived for estimating the ability parameters of the Rasch model when difficulty parameters are known. It is well established that a design is locally D-optimal if the ability and difficulty coincide. But locally optimal designs require that the ability parameters to be estimated are known. To attenuate this very restrictive assumption, prior knowledge on the ability parameter may be incorporated within a Bayesian approach. Several symmetric weight distributions, e.g., uniform, normal and logistic distributions, will be considered. Furthermore, maximin efficient designs are developed where the minimal efficiency is maximized over a specified range of ability parameters.  相似文献   
192.
193.
Previous studies have suggested that the effects of extinction are response-specific. The present study investigated whether an extinction treatment that eliminated goal tracking elicited by an appetitive conditioned stimulus (CS) would also eliminate the conditioned reinforcing effects of that CS. Rats were first trained on a goal-tracking procedure in which an auditory CS was paired with a food unconditioned stimulus. Animals learned to approach the location where the food was delivered. In a subsequent phase, rats in one group received extinction training that eliminated the goal-tracking elicited by the CS. Rats in the other group did not experience extinction of the food-paired CS. Then, both groups received a test for conditioned reinforcement in which leverpresses resulted in the brief presentation of the stimulus previously paired with food. This stimulus did not act as a conditioned reinforcer in the group that had been subjected to extinction training, but did serve as a conditioned reinforcer in the group that did not experience extinction. These results indicate that the effects of extinction generalize from the approach-eliciting to the conditioned reinforcing effects of an appetitive CS.  相似文献   
194.
Insufficient data on the nature and extent of children's vulnerability in Uganda has challenged government and donors in priority setting, resource allocation and developing effective approaches to improve well-being. We conducted a population-based survey among a nationally representative sample of 2551 households, covering a total of 7946 children. We engaged national stakeholders in a priority-setting exercise to develop a scoring system to assess dimensions of children's vulnerability. The exercise identified individual and household characteristics to assess vulnerability--many of which had not been measured previously--to which numerical weights representing vulnerability level were assigned. Highly weighted characteristics included maternal death, disability, child labour and pregnancy before age 17. Psychosocial elements included living apart from siblings, having nobody to talk to and never visiting a living parent. According to this approach, an estimated 51.1% of children in Uganda (weighted for national population distribution) are considered critically or moderately vulnerable. It is to these children, equivalent to a national total of 8.7 million, that support services should be prioritised. However, survey data suggest that the most critically vulnerable children are under-represented in several types of support services. This pioneering, participatory methodology provides a rudimentary, but valuable, first step towards quantifying the vulnerability of children in Uganda and assessing their resource needs. It has been used by the Government of Uganda to determine subcategories of vulnerability for resource allocation. A major advantage is that it uses local contextual knowledge of child vulnerability rather than generic criteria applied in international surveys. Further analytical work is required to validate the methodology, link it to child well-being outcomes and devise a practical tool for service providers to refine programme targeting. The approach may be useful to national, regional or local service providers seeking an overview of their client base to monitor and improve programme-targeting efforts.  相似文献   
195.
While community-based groups are able to provide vital support to people living with HIV/AIDS (PLHIV), their organizational and technical capacities are limited, and they frequently operate in isolation from PLHIV groups. We evaluated a three-year project implemented by the International HIV/AIDS Alliance in Uganda to increase the involvement of PLHIV in the HIV/AIDS response and to improve access to and utilization of prevention, treatment, care, and support services for households affected by HIV/AIDS. Information sources included project monitoring data, interviews with 113 key informants, and 17 focus group discussions in 11 districts. The evaluation found that PLHIV groups reached large numbers of people with education and awareness activities and made a growing number of referrals to health facilities and community-based services. The project trained individuals living openly with HIV as service providers in the community and at designated health facilities. Their presence helped to reduce the stigma that previously deterred PLHIV from seeking care and encouraged individuals to disclose their HIV status to spouses and family members. The project has put into practice the widely endorsed principles of greater and meaningful involvement of PLHIV in a systematic manner and on a large scale. A wide audience--ranging from grassroots PLHIV networks and AIDS service organizations to national-level non-governmental organizations, government agencies, and international organizations--can benefit from the lessons learned.  相似文献   
196.
This study examined the associations between emotion dysregulation and probable posttraumatic stress disorder (PTSD) among 180 African American undergraduates enrolled in a historically black college in the southern United States. Trauma-exposed participants with probable PTSD reported significantly higher levels of overall emotion dysregulation and the specific dimensions of lack of emotional acceptance, difficulties engaging in goal-directed behavior when upset, difficulties controlling impulsive behaviors when distressed, and limited access to effective emotion regulation strategies than participants without Criterion A traumatic exposure and those with Criterion A traumatic exposure but no PTSD (controlling for age and negative affect). Furthermore, results indicated that participants with Criterion A traumatic exposure but no PTSD were significantly less likely to report difficulties controlling impulsive behaviors when distressed and limited access to effective emotion regulation strategies than participants without Criterion A traumatic exposure (controlling for age and negative affect). These findings extend extant research on the role of emotion dysregulation in PTSD, thus providing support for the relevance of emotion dysregulation to PTSD among African American adults in particular.  相似文献   
197.
Abstract

Surgery, regardless of its kind and severity, can be regarded as a major stress situation for any patient. High preoperative emotional arousal may negatively influence adaptation during surgery and, consequently, rate of postoperative recovery. In a series of previous studies, our research group analyzed the influence of dispositional and actual coping on subjective and objective stress indicators before, during, and after surgery. The present study investigates the influence of the dispositional coping variables vigilance and cognitive avoidance on actual surgery-related coping, state anxiety, and indicators of intra- and postoperative adjustment. The sample consisted of 42 male and 42 female patients undergoing elective maxillofacial surgery under general anaesthesia. Dispositional coping was measured on the dimensions vigilance and cognitive avoidance with the Mainz Coping Inventory. Actual surgery-related coping was assessed by means of a newly constructed inventory containing items to measure the four dimensions avoidance, vigilance, positive restructuring, and seeking social support.

Self-reported state anxiety was differentiated according to the cognitive, affective, and somatic components. The patients' adaptation was assessed by measuring doses of the narcotic agents used for induction of anaesthesia, the intraoperative status, and the amount of postoperative (analgesic and psychotropic) medication. Significant effects of coping mode, gender, and time of measurement were observed on the cognitive, affective and somatic component of state anxiety, the indicators of intraoperative adaptation and on postoperative medication. Also, patients' actual coping behavior could partly be predicted by dispositional coping. Results indicate that actual coping behavior and gender should be taken into account when trying to predict adaptation and developing psychological preparatory intervention programs.  相似文献   
198.
This study investigated the role of inattention and working memory in predicting academic achievement in 145 adolescents aged 13 to 18 referred for attention deficit/hyperactivity disorder (ADHD). Path analysis was used to examine whether auditory-verbal and visual-spatial working memory would mediate the relationships between classroom inattention symptoms and achievement outcomes. Results provide support for the mediational model. Behavioral inattention significantly predicted both auditory-verbal and visual-spatial working memory performance. Auditory-verbal working memory was strongly associated with adolescents' achievement in reading and mathematics, while visual-spatial working memory was only associated with achievement in mathematics. The path from inattention symptoms to reading was partially mediated by the working memory variables, but the path from inattention to mathematics was not mediated by working memory. The proposed model demonstrated a good fit to the data and explained a substantial amount of variance in the adolescents' achievement outcomes. These findings imply that working memory is a risk factor for academic failure for adolescents with attentional problems.  相似文献   
199.
RESUMEN

El artículo presenta una teoría multimodal de la atención. Se supone que la atención es flexible, pudiendo hacer un análisis perceptual de la información de distinta profundidad. La información objetivo es seleccionada al nivel del análisis sensorial por los modos tempranos de la atención pero no lo es por los modos tardíos hasta después del análisis semántico. Mientras el sistema de análisis perceptual cambia de los modos tempranos a los tardíos, se recoge más información de las vías no-objetivo, pero requiere más capacidad para atender a la vía objetivo. El estudio comprueba con cinco experimentos los dos supuestos principales, a saber: que la atención requiere capacidad y que la cantidad de capacidad requerida se incrementa de los modos tempranos a los tardíos. En la discusión general los autores afirman que los datos apoyan estos dos supuestos de la teoría multimodal.  相似文献   
200.
Tests of cognitive ability play a major role in the selection of students. Still, data regarding the fairness of standardized tests in Germany is scarce. We use three samples (N = 2,616; 58% women) from German universities to investigate the sex‐specific differential prediction of college performance based on intelligence tests. The predictive bias we find is small and in line with US‐American research. The direction of the effect depends on the cognitive ability domain investigated: Numeric test scores are prone to disadvantage women whereas verbal test scores are more likely to discriminate against men. Including high school grade point average in the prediction model can help to offset differential prediction that underestimates women's academic achievement.  相似文献   
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