研究性学习与学生智力的开发

研究性学习的落脚点必须放在开发学生的智力上，只有实现了这个目标，才能走出研究性学习就学习而研究的误区。一、当前智力开发中存在的问题近代教育理论将智力概括为洞察力、适应力和控制力三个方面。完整的智力能力包括记忆、认知、思维（发散思维和辐合思维）、想像、评价等，小学生，特别是小学低年级学生，还主要处于记忆和认知的培养阶段。因此，这两个能力培养的效果将直接影响到以后更重要的三个能力的形成，考察现在的智力开发，我们认为存在以下几个问题：1.过分偏重记忆而忽视归纳和演绎思维。记忆是开发智力的基础，只有在记忆…     

Child maltreatment prevalence and mental disorders outcomes among American Indian women in primary care

OBJECTIVE: To examine (1) the prevalence, types, and severity of child abuse and neglect (CAN) and (2) the relationship between CAN and lifetime psychiatric disorders among American Indian women using primary care services. METHODS: A cross-sectional study was conducted among 234 American Indian women, age 18-45 who presented for outpatient ambulatory services at a community-based Indian Health Service Hospital in Albuquerque, New Mexico. Dependent measures included mood, substance abuse, and anxiety disorders as well as posttraumatic stress disorder (PTSD) as measured by the Composite International Diagnostic Interview. CAN was assessed using the Childhood Trauma Questionnaire. RESULTS: Approximately three-quarters of respondents (76.5%; 95% CI = 70.4, 81.7) reported some type of childhood abuse or neglect; over 40% reported exposure to severe maltreatment. Severity of child maltreatment was associated in a dose response manner with lifetime diagnosis of mental disorders. After adjusting for social and demographic correlates, severe child maltreatment was strongly associated with lifetime PTSD (prevalence ratio [PR] 3.9; 95% CI = 1.9, 8.0); and was moderately associated with lifetime substance use disorders (PR = 2.3; 95% CI = 1.6, 3.3); mood disorders (PR = 2.1; 95% CI 1.4, 3.2); and with two or more disorders (PR = 2.3; 95% CI = 1.6, 3.4). CONCLUSION: CAN was common in our sample of American Indian women in primary care and was positively associated with lifetime psychiatric disorders outcomes. Screening for CAN and psychiatric disorders would enhance the treatment of patients seeking primary care services. Primary prevention of child maltreatment might reduce the high prevalence of mental disorders among American Indian women.     

Assessment of different genetic distances in constructing cotton core subset by genotypic values

One hundred and sixty-eight genotypes of cotton from the same growing region were used as a germplasm group to study the validity of different genetic distances in constructing cotton core subset.Mixed linear model approach was employed to unbiasedly predict genotypic values of 20 traits for eliminating the environmental effect.Six commonly used genetic distances (Euclidean,standardized Euclidean,Mahalanobis,city block,cosine and correlation distances) combining four commonly used hierarchical cluster methods (single distance,complete distance,unweighted pair-group average and Ward's methods) were used in the least distance stepwise sampling (LDSS) method for constructing different core subsets.The analyses of variance (ANOVA) of different evaluating parameters showed that the validities of cosine and correlation distances were inferior to those of Euclidean,standardized Euclidean,Mahalanobis and city block distances.Standardized Euclidean distance was slightly more effective than Euclidean,Mahalanobis and city block distances.The principal analysis validated standardized Euclidean distance in the course of constructing practical core subsets.The covariance matrix of accessions might be ill-conditioned when Mahalanobis distance was used to calculate genetic distance at low sampling percentages,which led to bias in small-sized core subset construction.The standardized Euclidean distance is recommended in core subset construction with LDSS method.     

How children and adolescents evaluate gender and racial exclusion

Children's and adolescents' social reasoning about exclusion was assessed in three different social contexts. Participants (N = 294) at three ages, 10 years (4th grade), 13.7 years (7th grade), and 16.2 years (10th grade), fairly evenly divided by gender, from four ethnic groups, European-American (n = 109), African-American (n = 96), and a combined sample of Asian-American and Latin-American participants (n = 89) were interviewed regarding their social reasoning about exclusion based on group membership, gender, and race. The contexts for exclusion were friendship, peer, and school. Significant patterns of reasoning about exclusion were found for the context, the target (gender or race) of exclusion, and the degree to which social influence, authority expectations, and cultural norms explained children's judgments. There were also significant differences depending on the gender, age, and ethnicity of the participants. The findings support our theoretical proposal that exclusion is a multifaceted phenomenon and that different forms of reasoning are brought to bear on the issue. This model was drawn from social-cognitive domain theory, social psychological theories of stereotype knowledge and intergroup relationships, and developmental studies on peer relationships. The results contribute to an understanding of the factors involved in the developmental emergence of judgments about exclusion based on group membership as well as to the phenomena of prejudice, discrimination, and the fair treatment of others.     

Self-report of ADHD symptoms in university students: cross-gender and cross-national prevalence

Little research has examined the structure and prevalence of attention-deficit/hyperactivity disorder (ADHD) symptoms in university students, including whether symptom structure conforms to the bidimensional (i.e., inattention and hyperactivity-impulsivity) conceptualization of the Diagnostic and Statistical Manual of Mental Disorders (DSMV-IV; American Psychiatric Association, 1994) and whether self-reported symptoms vary across gender and country. A sample of 1,209 university students from three countries (Italy, New Zealand, and the United States) completed a 24-item self-report measure (the Young Adult Rating Scale) tapping ADHD symptomatology. Factor analyses within the U.S. and New Zealand samples supported a bidimensional symptom structure, whereas weaker support for this conceptualization was provided by the Italian sample. Participants did not vary significantly by gender in symptom report; however, Italian students reported significantly more inattention and hyperactivity-impulsivity symptoms than students from the United States, and students from New Zealand reported more inattention symptoms than students from the United States. The prevalence of self-reported ADHD symptoms beyond DSM-IV thresholds for diagnosis ranged from 0% (Italian women) to 8.1% (New Zealand men). The implications of these results for the use of DSM-IV criteria in identifying university students with ADHD are discussed.     

没有人知道其中的不同

学校志愿者们是没有酬金的,但有时候,我们会收到一些特殊的礼物。就在圣诞假期之前的一天早晨,我正在出售我们小学最后一晚“胡桃夹子”演出的入场券。前一天晚上的入场券全都售完了。人们列队挤在剧场的墙边,有些人甚至还从外面往里窥视,观看演出。那天,我的一位顾客是一个学生的家长。“我认为看我自己孩子的演出还要花钱买票简直太糟糕了,”她一边说一边从她的皮包里拽出一只皮夹来。“学校要求的是自愿捐款,用以支付布景和服装方面的费用,”我解释道,“因此,并不是必须付费才能进场的。我们很高兴把您需要的票送给您。”“噢,我要付费,…     

Science Letters： Simultaneous removal of nitrate and heavy metals by iron metal

INTRODUCTION Nitrate and heavy metals commonly found ingroundwater pollutants constitute significant healthrisk to humans and a burden on the environment.Mixtures of these compounds often exist in soils andgroundwater at numerous contaminated sites. Highnitrate (NO3 ) levels in drinking water supplies sig- ?nificantly endanger human health, as they are directlyresponsible for methemoglobinemia in infants (bluebaby syndrome) and may play a role in the develop-ment of som…     

A history of abuse and negative life events in patients with a sexually transmitted disease and in a community sample

OBJECTIVE: Our aim was to investigate the psychological impact of abuse and negative life events during childhood, adolescence and adulthood in patients recruited from a sexual health clinic. METHOD: Sixty-two patients with a sexually transmitted disease (STD) were matched on age and gender with a community sample. Forty-two patients without an STD formed another control group. Subjects self-reported their trauma histories and current psychological distress. RESULTS: Compared to controls, categories of abuse and negative life events were more prevalent in STD patients, particularly Physical/Sexual Abuse in adolescence and adulthood. Both within the STD and community samples, a negative life event category that measured illness/death of loved ones during childhood and adolescence predicted current psychological distress. In addition, Control Abuse (a subtype of psychological abuse involving selfish manipulation and deprivation) in childhood and adolescence strongly predicted current psychological distress in STD patients. In general, effects were stronger in females than in males. Psychological/Verbal Abuse did not independently predict current psychological distress, but accompanied other abuse types and possibly amplified their adverse effects. CONCLUSIONS: Our findings suggest that multiple types of abuse and negative life events increase the risk of STD infection, perhaps by increasing the likelihood of multiple sexual partners. These patients may ignore social conventions of sexual behaviour because they are bitter about past life experiences. Alternatively, they may persistently search for affection to compensate for a lack of affection in the past.     

Attachment security in infancy and early adulthood: a twenty-year longitudinal study

Sixty White middle-class infants were seen in the Ainsworth Strange Situation at 12 months of age; 50 of these participants (21 males, 29 females) were recontacted 20 years later and interviewed by using the Berkeley Adult Attachment Interview (AAI). The interviewers were blind to the participants' Strange Situation classifications. Overall, 72% of the infants received the same secure versus insecure attachment classification in early adulthood, K = .44, p < .001. As predicted by attachment theory, negative life events-defined as (1) loss of a parent, (2) parental divorce, (3) life-threatening illness of parent or child (e.g., diabetes, cancer, heart attack), (4) parental psychiatric disorder, and (5) physical or sexual abuse by a family member-were an important factor in change. Forty-four percent (8 of 18) of the infants whose mothers reported negative life events changed attachment classifications from infancy to early adulthood. Only 22% (7 of 32) of the infants whose mothers reported no such events changed classification, p < .05. These results support Bowlby's hypothesis that individual differences in attachment security can be stable across significant portions of the lifespan and yet remain open to revision in light of experience. The task now is to use a variety of research designs, measurement strategies, and study intervals to clarify the mechanisms underlying stability and change.