Prenatal depression, violence, substance use, and perception of support in pregnant middle-class women

The purpose of this study was to explore the vulnerability for postpartum depression among financially, educationally, and socially advantaged middle-class women (n = 31). Twenty-nine percent reported prenatal depression, 13% reported intimate partner violence, and 22% reported concerns with partner relationships and support expectations after delivery. No illegal substances were reported; however, a past history of smoking and excessive use of caffeine was disclosed. Implications for practice focus on the need to screen and implement intervention programs for these social problems and to adopt measures as a universal standard of care for all women, regardless of demographic advantages.     

Gender effects in children's beliefs about school performance: a cross-cultural study

Do young boys and girls understand what leads to academic success (e.g., talent, effort, good teaching, luck) in the same way? Do young girls and boys have equivalent perceptions of their academic competence? Are these beliefs engendered in the same way across sociocultural contexts? In a cross-cultural study of over 3,000 children in grades 2 to 6, ages 7.2 to 13.6, we discovered that boys and girls around the world have very similar ideas about what generally leads to academic success. Moreover, in the few contexts where boys' and girls' academic performances were equal, their beliefs were also equal. However, when girls outperformed boys, their beliefs in their own talent were no greater than boys' beliefs, even though they did have stronger beliefs than boys in other facets of their achievement potential (e.g., putting forth effort, being lucky, getting their teacher's help). Our findings support the generally close correspondence between children's achievement and their competence-related beliefs, with the exception that young girls appear to specifically discount their talent. The effects held regardless of the children's achievement, intelligence, or age (approximately 8 to 13 years). Girls were more biased in some contexts than in others, however, suggesting that competence-related biases are rooted in culture-specific aspects of school settings.     

Acculturation, substance use, and deviant behavior: examining separation and family conflict as mediators

This longitudinal study examined how separation and family conflict mediated the effects of two acculturation variables (English language use and generational status) on substance use (alcohol, tobacco, and marijuana use) and deviant behavior outcomes in a Mexican American high school age sample. Structural equation modeling indicated that separation was a significant mediator of the relationship between acculturation and alcohol use, tobacco use, and deviant behavior. Family conflict mediated the effects of acculturation on marijuana use and deviant behavior. Model comparisons across gender groups suggested that generational status was an influential acculturation measure for females but not males. Additionally, English language use maintained a direct effect on marijuana use among females, whereas this relationship was mediated by separation for males.     

The relationship between instructional and assessment accommodations in an inclusive state accountability system

We investigated the kinds of instructional and assessment accommodations students with disabilities receive, and the extent to which instructional accommodations match assessment accommodations. Most students who had IEPs in specific content areas received instructional accommodations in those areas, and there were no differences by disability type. We provide data on the specific types of accommodations used. Overall, students' assessment accommodations matched their instructional accommodations, though many students received testing accommodations that had not been received in instruction. Implications are discussed for IEP teams who make decisions about instructional and assessment accommodations.     

农业中的放射性同位素

原子核的秘密的揭露,使人类掌握了新的無穷尽的能源。第一座原子能电站在苏联的建立,为將这个能源实际利用于工業和农業的和平目的,奠定了基础。原子技术的發展,开辟了把放射性同位素应用到各种全然不同的科学技术部門中去的广闊的可能性。人工取得放射性同位素的方法之一,是在原子核反应堆中用中子来照射。比如,用中子照射普通的天然的磷的时候,部分的磷原子核就和中子結合而变成磷的放射性同位素(磷-32)的原子核。当放射性磷的核衰变的时候,核中的一个中子轉化成質子,同时放射出一个β粒子(帶陰电的电子)。衰变是按照这个方式發生     

人造元素

关于化学元素的学说,构成了化学的基本内容,我们周围世界中所有的复杂物质就是由这些元素组成的。在长时期内,人们一直认为元素是不可改变的,并且没有共同的联系。直到1869年,门捷列也夫才发现了所有化学元素的普遍规律性,并且在这个基础上创立了著名的周期系。这位伟大的俄罗斯学者的科学成就,标志着化学上新纪元的开始。门捷列也夫的发现的重要意义是:他确定了所有元素的化学性质随着它们原子量的增加的有规律的周期的重覆性。门捷列也夫把性质相似的元素一个个地上下对齐,这样就组成了周期表。他证明了,每一种化学元素的原子都有着一定的形态,这种形态的特徵不仅仅是由原     

信息科学：新的集成观（2）

2.1 知识的范围 数据、信息、知识和智慧可以看作是一个连续统一体中的组成部分,它们之中的一个可以引导出另一个,它们之间没有明显的界限。 知识的范围如图1所示。图中,“事件”指发生的一件事、一些条件或社会状态的变化。如果我们想要与这些状态或条件打交道,就必须把它表达出来。我们发明“符号”——数字、字母、雕像或图象作为事件的表达。当我们使用一定规则将这些符号组织起来,就产生了“数据”。我们的数字系统和语言都是这样的表述形式。     

诞生生命的残骸

银河系中的一颗超新星为我们提供了行星和人类起源的线索。[编者按]     

79 new cyclopeptides discovered from 28 plants

A key innovative research result has been achieved in systematic chemistry of plant cyclopeptides (PCPs), a group of important plant metabolites, by a research team with the CAS Kunming Institute of Botany (KIB)in the capital of southwest China's Yunnan Province. According to a recent announcement released by the Institute, its chemists have brought to light 79 new PCPs.