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141.
142.
A domain-specific hierarchical conceptualization of mathematics achievement can be represented by the standard psychometric model in which a single latent dimension accounts for observed individual differences in scores on the respective subdomains (e.g., quantity). Alternatively, a fully hierarchical conceptualization of achievement can be represented by a nested-factor model in which individual differences in subdomain-specific scores are explained by both general student achievement and specific mathematics achievement. The authors applied both models to study the gender similarity hypothesis, the greater male variability hypothesis, and the masking hypothesis, which predicts that gender differences in general student achievement mask gender differences in both the means and the variability of specific mathematics achievement. Representative data were obtained from 275,369 15-year-old students in 41 countries. The results supported these hypotheses in most countries, demonstrating that a fully hierarchical conceptualization of achievement in terms of the nested-factor model significantly contributes to a better understanding of gender differences in the mean level, variability, and shape of students' achievement profiles.  相似文献   
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Sexually transmitted infections and (STIs) unintended pregnancies are contemporary public health concerns. Understanding factors (e.g. knowledge, attitudes and skills) influencing sexual behaviours of university students are critical to develop targeted and tailored risk-reduction interventions for this vulnerable population. Thus, the goals of this study were to describe sexual behaviours and analyze differences between genders for sexual behaviours; to identify whether differences exist between genders and age groups regarding knowledge, attitudes and skills concerning contraceptive methods and STIs, and to evaluate the association of knowledge with attitudes and skills with sexual behaviour among university students in Portugal. The sample included 3278 students. Results show that the majority were sexually active and use condoms and oral contraceptives. In general, university students have high knowledge, positive attitudes and skills about contraception and STIs. Gender analyses indicated that women had greater knowledge, and more favourable attitudes, and higher skills toward contraceptive and STI preventive behaviour College students, in particular, face new challenges in sexual health and would benefit from more comprehensive education aimed at promoting healthy decision-making about family planning and STI prevention.  相似文献   
145.
A conversation is made up of visual and auditory signals in a complex flow of events. What is the relative importance of these components for young children's ability to maintain attention on a conversation? In the present set of experiments the visual and auditory signals were disentangled in four filmed events. The visual events were either accompanied by the speech sounds of the conversation or by matched motor sounds and the auditory events by either the natural visual turn taking of the conversation or a matched turn taking of toy trucks. A cornea-reflection technique was used to record the gaze-pattern of subjects while they were looking at the films. Three age groups of typically developing children were studied; 6-month-olds, 1-year-olds and 3-year-olds. The results show that the children are more attracted by the social component of the conversation independent of the kind of sound used. Older children find spoken language more interesting than motor sound. Children look longer at the speaking agent when humans maintain the conversation. The study revealed that children are more attracted to the mouth than to the eyes area. The ability to make more predictive gaze shifts develops gradually over age.  相似文献   
146.
The incidence of infection with HIV/AIDS among the heterosexual population has been increasing in young adults. The goal of this research was to deepen knowledge of preventive sexual behavior in Portuguese adolescents, including knowledge and attitudes about HIV/AIDS, and assessing whether they changed from 2002 to 2006. Data were collected through a self-administered questionnaire from the Portuguese sample of the Health Behavior in School-aged Children (HBSC), a collaborative WHO study. The study provides national representative data of 7093 Portuguese adolescents, randomly chosen from those attending 8th and 10th grade of high school. Results showed there was an increase in the age of first sexual intercourse and a decrease in the number of teenagers who reported having had sexual intercourse, also in the level of information regarding HIV/AIDS transmission/prevention and in positive attitudes towards people with HIV/AIDS. In general, adolescents have good knowledge about how to protect themselves from becoming infected. However, comparing to 2002, there was a reduction of knowledge and consequent increase in the doubts regarding HIV/AIDS. Given the incipient state of sex education in 2006, the results cannot be attributed to sex education, but they will be relevant for comparison with the 2010 HBSC results.  相似文献   
147.
The objective is to examine the effects of reminiscence therapy (RT) on total, episodic and semantic autobiographical memory in amnestic mild cognitive impairment (aMCI) and Alzheimer's disease (AD) groups, testing the effects of RT on different stages of autobiographical memory, and its effectiveness at follow‐up. A sample composed of 43 aMCI (27 treatments, 16 controls) and 30 AD (15 treatments, 15 controls) subjects were evaluated with the Autobiographical Memory Interview (AMI) test. The RT consisted of 10 sessions lasting 60 minutes each. Both groups, aMCI and AD, showed significant effects on overall autobiographical memory; aMCI showed significant main effects on episodic and semantic autobiographical memory in the treatment group, increasing scores in both cases. For AD, significant effects were observed on autobiographical episodic memory, showing an increase in the treatment group from Time 1 to follow‐up; semantic memory showed a decrease in the control group from Time 1 to follow‐up. Results show that RT implementation and follow‐up are effective in increasing autobiographical memory in subjects with aMCI and AD.  相似文献   
148.
Why do individuals mentally modify reality (e.g., “If it hadn’t rained, we would have won the game”)? According to the dominant view, counterfactuals primarily serve to prepare future performance. In fact, individuals who have just failed a task tend to modify the uncontrollable features of their attempt (e.g., “If the rules of the game were different, I would have won it”), generating counterfactuals that are unlikely to play any preparatory role. By contrast, they generate prefactuals that focus on the controllable features of their ensuing behavior (e.g., “If I concentrate more, I will win the next game”). Here, we test whether this tendency is robust and general. Studies 1a and 1b replicate this tendency and show that it occurs regardless of whether individuals think about their failures or their successes. Study 2 shows that individuals generate relatively few controllable counterfactuals, unless explicitly prompted to do so. These results raise some questions regarding the generality of the dominant view according to which counterfactuals mainly serve a preparatory function.  相似文献   
149.
We evaluated change in cytochrome oxidase (COx) activity of the hippocampus and related structures of the limbic system following spatial working memory learning in rats after treatment with tacrine (8.0mg/kg). Control groups treated with saline and tacrine and an untreated group were added. Acetylcholinesterase optical density levels were also measured. The tacrine and saline groups showed similar behavioral results, but a decrease in COx activity was found in the tacrine group in the prefrontal cortex, nucleus accumbens, anterior thalamus, hippocampus and nucleus basalis of Meynert. Similarly, acetylcholinesterase levels of the tacrine group were lower in most of the regions. Learning-related increase in COx activity was found in the prefrontal cortex and dentate gyrus in the saline group. The tacrine group presented the same increase in the anterodorsal thalamus, dentate gyrus, CA3 and mammillary nuclei. These results suggest that inhibition of the acetylcholinesterase produces a different pattern of learning-related neuronal activity in the limbic system of the rat.  相似文献   
150.
Studies from many languages consistently report that subject relative clauses (SR) are easier to process than object relatives (OR). However, Hsiao and Gibson (2003) report an OR preference for Chinese, a finding that has been contested. Here we report faster OR versus SR processing in Basque, an ergative, head-final language with pre-nominal relative clauses. A self-paced reading task was used in Experiments 1 and 2, while ERPs were recorded in Experiment 3. We used relative clauses that were ambiguous between an object or subject-gap interpretation and disambiguated later in the sentence. The results of Experiments 1 and 2 showed that SR took longer to read than OR in the critical disambiguating region. In addition, Experiment 3 showed that SR produced larger amplitudes than OR in the P600 window immediately after reading the critical disambiguating word. Our results suggest that SR are not universally easier to process. They cast doubts on universal hypotheses and suggest that processing complexity may depend on language-specific aspects of grammar.  相似文献   
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