Botany on a plate. Pleasure and the power of pictures in promoting early nineteenth-century scientific knowledge

In early nineteenth-century Britain the use of pictures in introducing novices to the study of science was contentious, leading to debates over the ways in which words and images constituted knowledge and over the role of pleasure in intellectual pursuits. While recent studies have stressed visual representation as a critical element of science and considered its relation to the written word in conveying information, this essay explores the nineteenth-century preoccupation with the mind and mental faculties in relation to corporeal responses to explain concerns over the role of images and the process of recognition. By considering illustration in this way, it argues that popular botany was defined by many expert naturalists as the means by which private individuals could best be encouraged to extend their aesthetic appreciation and love of plants to an active and participatory pursuit of science.     

爱上初恋

我不知道我为什么会喜欢他 我也不知道,我为什么会这样喜欢他,可我又是这样懦弱,我不敢告诉他.     

The complexity of trauma response: a 4-year follow-up of adolescent Cambodian refugees

OBJECTIVE: The objective of this study was to document the psychosocial adjustment of young refugees during their adolescence and its association with the war-related trauma experienced by their family before migration. METHOD: Data were collected on 57 young Khmer resettled in Montreal and followed from early to late adolescence. The associations between premigratory exposure to political violence and postmigratory mental health and social adjustment were estimated for early, mid-, and late adolescence. RESULTS: The associations between premigratory exposure to political violence and postmigratory psychosocial adjustment fluctuated over the adolescence period. Overall, the adolescents whose families were more highly exposed to political violence tended to report a more positive social adjustment and less mental health symptoms than those less exposed. CONCLUSION: The high expectations of Cambodian parents towards their children and the preservation of traditional values despite the Khmer rouge attempts to eradicate them might contribute to explain the paradoxical association between the families' exposure to political violence and the adolescents' psychosocial adjustment in the host country. Although children and adult refugees seen in clinical setting are reminders of the negative effects of adversity, resilience should be more systematically explored in community samples to further our understanding of the long-term effects of trauma.     

动态在线讨论：交互式学习环境中的深层学习

本文阐述了在远程教育中进行面向深层学习的动态在线讨论的一个框架。该框架建立在信息、方法和认知等三个普遍性过程的基础上。在本框架中进行动态讨论的结构包括三种在线讨论的类型,即灵活的同伴、结构化的主题和协作性任务讨论。该框架在一门有关教学多媒体设计的在线研究生课程中使用过两个学期。创建动态讨论的策略是为了促进不同学习者之间的在线交互,并有助于设计能实现有效交互的任务。学生通过设计的任务产生了接受性学习,在此基础上促进了适应性学习,并且激发了他们促进深层学习的认知能力。该框架及动态讨论的策略提供了一个在线学习环境,在这样的环境中学生的学习超越了既定的课程目标。     

我们对儿童的需要都了解了吗?(一)

看来,没有一个家长会不希望教会孩子劳动,让孩子体验劳动的乐趣的。但是我们平时所采取的教育方法,对待孩子的习惯性方式,是否都能促进(或者只要不妨碍)孩子们对劳动本身兴趣的巩固呢?     

畜牧业中光周期現象的应用

动植物对于一定季节是有严格的适应性的。例如:某种植物在夏初开花,另一些則在夏末或秋天开花。在动物的繁殖方面也有相同情况:某些种在夏季交配,另一些則在秋天。在冬天来临以前,动植物都作着过冬的准备:植物形成了貯藏着大量碳水化合物、脂肪的块根、块莖和根莖。动物則長眫了,長出了丰滿的冬羽和毛皮,許多昆虫停止了生長和繁殖而进入了特殊的停育狀态……。生活在北方溫帶的植物,这种适应性原因在于光照时間,这个外部条件对有机体結構及机能方面的影响称为“光周期現象”。 將近半数的植物和兽类以及絕大多数的鳥类均屬于長日照类型,長的光照时間有利于它們的生育。这一类的植物(小麦、大麦、黑麦、燕麦、亞麻等)如果日照短于5—8小时就不能开花,这一类的动物(食肉目、啮齿目、馬科、烏綱)的生殖腺,如果目照不超过9—12小时則不能正常地发育。     

Do allegations of emotional maltreatment predict developmental outcomes beyond that of other forms of maltreatment?

OBJECTIVES: To understand the features of child abuse/neglect (CA/N) allegations in cases with emotional maltreatment (EMT) allegations, as well as the features of the EMT allegations themselves, and to describe any associations of EMT with distinct impairments of children's behavior, emotion and functioning. METHOD: The sample consisted of 806 high-risk children, 545 with one or more maltreatment reports to CPS. The Maltreatment Classification System was used to record the number and severity levels of maltreatment allegations, which compared cases with and without EMT. Multiple regression analyses were conducted using 10 outcome scales from the Child Behavior Checklist, Vineland Screener, and Trauma Symptom Checklist. Successive blocks of predictor variables included demographics, maltreatment classification variables, maternal and family characteristics, and study site. RESULTS: When there were allegations of EMT as well as CA/N in a CPS case-record (by age 8), the CA/N allegations tended to be either more frequent or less severe than those kinds of allegations in cases without EMT. When neglect was alleged to occur with EMT, neglect allegations outnumbered allegations of EMT. However, when sexual abuse allegations were accompanied by EMT allegations, there were more EMT allegations than sexual abuse allegations in the cases. Higher severity ratings for EMT allegations than for physical abuse occurred when cases included any abuse. Distinctive effects of EMT subtypes were found between problems of safety/restriction and self-reported anger symptoms, and between problems of self-esteem/autonomy and posttraumatic stress. CONCLUSION: Differences exist between the CA/N allegations in cases with and without EMT. Having few cases containing only EMT allegations made it difficult to assess distinctive harm associated with EMT. Certain types of EMT allegations were associated with increases in children's anger and posttraumatic stress.     

氟聚合物纤维满足非织造布技术要求

聚四氟乙烯(PTFE)具有一些物理和化学特性，如耐热和耐化学性、高绝缘和低摩擦等。由于这些性能，它的产品能用在恶劣的过滤条件下，使用效果很好。因此，聚四氟乙烯过滤介质主要用在垃圾焚烧炉、发电厂和其它工业焚化炉的热气体过滤。其短纤维截面形状的绝对不规则也有助于提高过滤效率。     

New plant species brought to light in Sichuan

A new species of the wild orchids was recently discovered and identified by an expeditionary team of Chinese and US botanists when sorting out the specimens collected from a wildlife survey conducted in 2004 in Sichuan Province.