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1.
Abstract

Maternal dietary habits influence maternal and foetal health, representing a pathway for intervention to maximise pregnancy outcomes. Advice on energy intake is provided on a trimester basis, with no additional calories required in the first trimester and an additional 340?kcal?d?1 and 452?kcal?d?1 needed for the second and third trimesters. Energy intake depends on pre-gravid body mass index (BMI); underweight women are recommended an increase of 150, 200 and 300?kcal?d?1 during the first, second and third trimester, normal weight women an increase of 0, 350 and 500?kcal?d?1 and obese women an increase of 0, 450 and 350?kcal?day?1. The recommendations for carbohydrate and protein intake are 175?g?d?1 and 0.88–1.1?g?kgBM?d?1, with no change to fat intake. The number of pre-gravid obese women is rising; therefore, we need to regulate weight in women of childbearing age and limit gestational weight gain to within the recommended ranges [overweight women 6.8–11.3?kg and obese women 5.0–9.1?kg]. This can be achieved using nutritional interventions, as dietary changes have been shown to help with gestational weight management. As pregnancy has been identified as a risk factor for the development of obesity, normal weight women should gain 11.5–16.0?kg during pregnancy. While some research has shown that dietary interventions help to regulate gestational weight gain and promote postpartum weight loss to some extent, future research is needed to provide safe and effective guidelines to maximise these effects, while benefitting maternal and foetal health.  相似文献   
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This research examines factors influencing elementary science teacher learning as they participate in professional development with and enactment of educative curricula in comparison with learning following limited professional development and enactment of traditional curricula. Using a randomized cluster design (125 teachers and 2,694 students in 4th—5th grades) that met the What Works Clearinghouse standards without reservations, teacher learning was conceptualized using four outcomes. Data were analyzed using standard single-level multiple regression models and possible mediation models for the teacher outcomes were considered using piecewise multiple regression and path analytic approaches. Treatment group teachers experienced greater increases in content knowledge, views of science inquiry, beliefs about reform-based teaching, and teaching self-efficacy than comparison group teachers. The findings indicate that what teachers learn from the combination of professional development and teaching with educative curriculum varies according to what their knowledge and beliefs are on entering the experience. Surprisingly, high entry-level self-efficacy was associated not only with lower learning gains for the teachers, but also for their students. Finally, teachers' space science learning and that of their students are implicated as mediators of the positive effect of the professional development and educative curriculum enactment on teacher beliefs about reform science teaching. This work refines and extends a theoretical framework of teachers' participatory relationship with curricula.  相似文献   
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This paper focuses on seven major managerial practices and three negative conditions that must be managed to enhance employee growth and development. These managerial practices and conditions have significant potential for human resource development practitioners and performance improvement technologists by providing new perspectives to improve employee performance through employee growth and development activities. Surveys measuring employee perceptions of manager behaviors were administered to 503 MBA and PhD students from the United States, resulting in 463 useable responses. The hypotheses were tested using linear regression and structural equation modeling. Based on the analysis, the researchers found that involving employees in decision making, motivating employees, treating employees as unique individuals, and making certain that managers are effective have the highest influence on employee growth and development.  相似文献   
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We have taken to heart the call of critical race theorists and critical Whiteness scholars to open up a White discourse on White racism. As White, female, teacher educators, we endeavored to openly address Whiteness and White racism with our White students to help them become more aware of the advantages and biases inherent in their positionality as White teachers. As we did this, we were critically aware of both the negative and positive possible outcomes of our endeavors. Throughout our work with our students and our subsequent reflections on the results, we were able to establish ways of speaking about Whiteness that moved our students, and ourselves, to a more critical, more empowered understanding of race and Whiteness.  相似文献   
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We digitized three years of Dutch election manifestos annotated by the Dutch political scientist Isaac Lipschits. We used these data to train a classifier that can automatically label new, unseen election manifestos with themes. Having the manifestos in a uniform XML format with all paragraphs annotated with their themes has advantages for both electronic publishing of the data and diachronic comparative data analysis. The data that we created will be disclosed to the public through a search interface. This means that it will be possible to query the data and filter them on themes and parties. We optimized the Lipschits classifier on the task of classifying election manifestos using models trained on earlier years. We built a classifier that is suited for classifying election manifestos from 2002 onwards using the data from the 1980s and 1990s. We evaluated the results by having a domain expert manually assess a sample of the classified data. We found that our automatic classifier obtains the same precision as a human classifier on unseen data. Its recall could be improved by extending the set of themes with newly emerged themes. Thus when using old political texts to classify new texts, work is needed to link and expand the set of themes to newer topics.  相似文献   
9.

This study describes the trends in students' explanations of biological change in organisms. A total of 96 student volunteers (8 students from each of 2nd, 5th, 8th, and 12th grades from 3 localities) were interviewed individually and each student was presented a series of graphics depicting natural phenomena. Students' explanations to questions of how something occurred were assigned to one of three categories (responses addressing how something occurred, why something occurred, and 'I don't know'). While the number of responses in each category was roughly equivalent in prominence across grade levels, the majority of students were unable to offer a causal explanation of how a phenomena occurred. An unexpected phenomenon was the students' predilection to redirect the interview question so they could answer them. If asked a how question, as they were in every interview instance, 32% the students answered with a 'why' response. The way biology is taught, the structure of biology or/and how we learn it could shed some light into this phenomenon and has implications for science educators.  相似文献   
10.
The performance and capabilities of Web search engines is an important and significant area of research. Millions of people world wide use Web search engines very day. This paper reports the results of a major study examining the overlap among results retrieved by multiple Web search engines for a large set of more than 10,000 queries. Previous smaller studies have discussed a lack of overlap in results returned by Web search engines for the same queries. The goal of the current study was to conduct a large-scale study to measure the overlap of search results on the first result page (both non-sponsored and sponsored) across the four most popular Web search engines, at specific points in time using a large number of queries. The Web search engines included in the study were MSN Search, Google, Yahoo! and Ask Jeeves. Our study then compares these results with the first page results retrieved for the same queries by the metasearch engine Dogpile.com. Two sets of randomly selected user-entered queries, one set was 10,316 queries and the other 12,570 queries, from Infospace’s Dogpile.com search engine (the first set was from Dogpile, the second was from across the Infospace Network of search properties were submitted to the four single Web search engines). Findings show that the percent of total results unique to only one of the four Web search engines was 84.9%, shared by two of the three Web search engines was 11.4%, shared by three of the Web search engines was 2.6%, and shared by all four Web search engines was 1.1%. This small degree of overlap shows the significant difference in the way major Web search engines retrieve and rank results in response to given queries. Results point to the value of metasearch engines in Web retrieval to overcome the biases of individual search engines.  相似文献   
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