Discriminating between reward-produced memories: Effects of differences in reward magnitude     

E. J. Capaldi  Suzan Alptekin  Kimberly Birmingham 《Learning & behavior》1997,25(2):171-176

The greater the dissimilarity between exteroceptive stimuli, the easier it is to discriminate between them. To determine whether a similar relationship holds for memories produced by reward events, rats in three runway investigations received trials in pairs, the number of food pellets (0.045 g) occurring on Trial 1 indicating whether reward or nonreward would occur on Trial 2. In each investigation, discriminative responding on Trial 2 was better the larger the difference in reward magnitude on Trial 1. This finding was obtained under a wide variety of conditions: for example, when the larger of two reward magnitudes on Trial 1 signaled nonreward on Trial 2 (Experiment 1, 10 vs. 2 pellets); when the smaller of two reward magnitudes on Trial 1 signaled nonreward on Trial 2 (Experiment 2, 10 vs. 2 pellets); and when the same magnitude of reward on Trial 1 signaled nonreward on Trial 2 (Experiment 3, either 5 pellets or 0 pellets). The findings obtained here indicate that the greater the dissimilarity between reward magnitudes, the greater the dissimilarity between the memories they produced and, thus, the easier it is to discriminate between them. It is suggested that the present results may provide a basis for understanding findings obtained in other instrumental learning investigations in which reward magnitude is varied.  相似文献   

Gardnerella vaginalis infection and sexual contact in female children     

David L. Ingram  Susanne T. White  Pauline R. Lyna  Kimberly F. Crews  J.E. Schmid  V.Denise Everett  G.G. Koch 《Child abuse & neglect》1992,16(6):847-853

Gardnerella vaginalis (GV) infection has been reported as being acquired via sexual contact in adults and as an indicator of sexual contact in female children (DeJong, 1985). The purpose of this study was to determine if GV infection was more commonly found in 191 female children who gave a history of sexual contact and/or were infected with Neisseria gonorrhoeae (GC) or Chlamydia trachomatis (CT) (Group 1), compared with 144 female children evaluated for possible sexual abuse and found to have no such history or infection with GC or CT (Group 2), or 31 female children (friends of the authors) without such a history or GC or CT infection (Group 3). Vaginal GV was found in 5.3% of Group 1, 4.9% of Group 2 and 6.4% of Group 3 (p > .05). Also, vaginal GV infection was not related to the type of sexual contact or race, but did increase with age in white female children. Because vaginal GV infection is not more commonly found in children with a history of sexual contact than those without such a history, the finding of GV in a vaginal culture in an individual case would not be a reliable marker of sexual contact. Routine culturing for GV is not recommended as part of a sexual abuse workup.  相似文献   

Family risk factors and prevalence of dissociative symptoms among homeless and runaway youth     

Tyler KA  Cauce AM  Whitbeck L 《Child abuse & neglect》2004,28(3):355-366

OBJECTIVE: To examine family risk factors associated with dissociative symptoms among homeless and runaway youth. METHOD: Three hundred and twenty-eight homeless and runaway youth were interviewed using a systematic sampling strategy in metropolitan Seattle. Homeless young people were interviewed on the streets and in shelters by outreach workers in youth service agencies. RESULTS: The current study revealed widespread prevalence of dissociative symptoms among these young people. Multivariate analyses revealed that sexual abuse, physical abuse, and family mental health problems were all positively associated with dissociative symptoms. No gender differences were found for any of the models. CONCLUSIONS: Dissociative behavior is widespread among these youth and may pose a serious mental health concern. Some young people experience numerous stressors, and with few resources and little support available, many may invoke maladaptive strategies such as dissociative behavior to handle such situations, which may in turn be detrimental to their mental health. Unless youth are provided with programs and intervention, the cycle of abuse that they have experienced at home is likely to continue on the street.  相似文献   

The Social Sensitivity of Preschoolers in Peer Conflicts: Do Children Act Differently with Different Peers?     

Mary T. Rourke  Robert H. Wozniak  Kimberly Wright Cassidy 《Early education and development》1999,10(2):209-227

This study sought to demonstrate that many aspects of preschoolers' peer conflict behavior are sensitive to the subtle change in social situation that occurs when a child plays with a different partner. Twenty-seven pairs of preschoolers were videotaped over four 15-minute play sessions; in the fourth session, half of the pairs played with a different partner, while half were with the same partner. Frequency and theme of conflicts, strategies used, frequency of yielding to partner, and percentage of conflicts solved were observed. Initiating and negotiating behavior in early sessions better predicted behavior in the fourth session for the same-partner (vs. change-partner) group, and thus emerged as behaviors sensitive to social context changes. Results indicate that preschoolers have a remarkably varied array of conflict behaviors and that much of their conflict behavior is sensitive to influences inherent to social interaction with a specific partner. Ways in which the apparent sophistication in young children's social understanding can inform developmental approaches to early childhood education as well as both preventative and therapeutic conflict resolution programs are discussed.  相似文献   

Inservice Elementary and Middle School Teachers’ Conceptions of Photosynthesis and Respiration     

Rebecca McNall Krall  Kimberly H. Lott  Carol L. Wymer 《Journal of Science Teacher Education》2009,20(1):41-55

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Does teaching complex sentences have to be complicated? Lessons from children's online writing     

Alison Kelly  Kimberly Safford 《Literacy》2009,43(3):118-122

This paper draws upon data from a research project, undertaken in 2 Year 6 classrooms during the 2006 World Cup, to analyse how children used complex sentence structures in their writing on a football web‐log. We explore how the confluence of a temporary, popular, global event and an online forum for communication created a moment of linguistic empowerment where pupils began to use high‐level forms of language, and we consider the implications of transience and interactivity for the teaching and learning of sentence grammar.  相似文献   

Connecting religion and teacher identity: The unexplored relationship between teachers and religion in public schools     

Kimberly R. White 《Teaching and Teacher Education》2009

It is increasingly acknowledged that for individuals to participate in a pluralistic and democratic society, they must understand religious conviction and difference. In educational literature, the discussion surrounding education and religion focuses on the implications for students. It is important to consider what this may mean to the teachers, as teachers directly influence student learning. This article uses literature on religion, multiculturalism, teacher identity, and popular culture to connect teachers' private religious identifications to their professional identities in public school classrooms. It supports future research in this area and provides a theoretical framework for subsequent studies.  相似文献   

The need for a General Comment for Article 19 of the UN Convention on the Rights of the Child: Toward enlightenment and progress for child protection     

Susan Bennett  Stuart N. Hart  Kimberly Ann Svevo-Cianci 《Child abuse & neglect》2009,33(11):783-790

ObjectiveTo present the need and plan for development of a General Comment for the UN Convention on the Rights of the Child Article 19 which has the potential to transform and advance child protection through the infusion of a child rights approach.MethodsThe Committee on the Rights of the Child (Committee) authorized ISPCAN and IICRD to draft a General Comment for CRC Article 19 (GC19) and to introduce implementation supports. An international working group (GC19WG), Expert Advisory Panel (EAP), and GC19 Focal Group of Committee members (GC19 CRC FG) have been organized to help guide and carry out the program of development. Analyses of relevant histories and knowledge, including effective and promising child protection strategies, are being applied to guide formulation of the GC and high priority implementation components. Consultations on the draft and supportive products will be conducted in cooperation with UNICEF, WHO, the NGO Group for the CRC, and other NGOs.Advice is to be solicited from interested parties and organizations in person and through distance communication throughout the world.ResultsIn addition to the GC19, numerous implementation supports will be planned and some will be produced and piloted during the program of development. Under consideration are an implementation guide and resources; commentary; accountability models, indicators, measures and evaluation systems; a clearing house and resource website; a child-appropriate version of GC19; and education/training curricula and programs.Practice implicationsGC19 has the potential to transform child protection by fostering a paradigm shift in its conceptualization, theory, research, and practice. Article 19 encourages an interpretation and application beyond narrow child protection conceptualizations and practices which have been found seriously inadequate. The General Comment can advance effective prevention of maltreatment and protection of personal security by promoting the child's rights, well-being, health, and development in all aspects of child protection. GC19 will provide support to the Committee on the Rights of the Child in its monitoring and guiding functions, and to States Parties, professionals, and civil society agents concerned with the protection and well-being of children.  相似文献   

Associations between blocking,monitoring, and filtering software on the home computer and youth-reported unwanted exposure to sexual material online     

Michele L. Ybarra  David Finkelhor  Kimberly J. Mitchell  Janis Wolak 《Child abuse & neglect》2009,33(12):857-869

ObjectiveTo examine the relationship between the use of preventive software on the home computer and unwanted exposure to sexual material online.MethodsThe Youth Internet Safety Survey-2 was a national, RDD telephone survey conducted in March–June 2005. Eight hundred households (one caregiver and one child between the ages of 10 and 17 years) with home Internet access answered questions pertaining to Internet prevention activities in the household and adolescent behaviors and exposures online.ResultsUnwanted exposure to sexual material occurred in 32% of youth in homes with pop-up/spam blockers and 25% of youth in homes with filtering, blocking, or monitoring software on the home computer, compared to 43% of households without preventive software installed on the home computer. Among otherwise similar youth, pop-up/spam blockers installed on the home computer were significantly associated with 59% lower odds of reporting unwanted exposure to sexual material on the home computer; and filtering, blocking, or monitoring software was significantly associated with 65% lower odds. When data were stratified by youth sex, associations between preventive software and unwanted exposure were similar for boys and girls. When stratified by age, preventive software was associated with significantly reduced risk of unwanted exposure for 10–12-year olds and 13–15-year olds, but not for 16–17-year olds.ConclusionAlthough these correlational analyses are far from providing conclusive evidence that preventive software protects children from unwanted exposure to sexual material online, findings suggest that caregivers of boys and girls 15 years of age and younger who want to reduce the likelihood of unwanted exposure to sexual material on the home computer should consider including preventive software—especially filtering, blocking, or monitoring software—in their Internet safety plan.Practice implicationsPractitioners should partner with caregivers in developing an Internet safety plan, including proactive caregiver-youth discussions about expected Internet behavior appropriate for their household.  相似文献   

Can Inquiry and Reflection be Contagious? Science Teachers, Students, and Action Research     

Kimberly Lebak  Ron Tinsley 《Journal of Science Teacher Education》2010,21(8):953-970

This study reports the transformations of 3 science teachers who conducted action research projects following a model, unique to our graduate program, which follows the theoretical tenets of adult and transformative learning theory. Teachers video their teaching, engage in weekly peer group collaborative reflection sessions, collaborate with students, and consult with other sources to identify goals for improving their teaching practices, develop action plans, and analyze the results of their actions. As a result of this process, all 3 teachers changed their pedagogical approach from a teacher centered textbook driven approach to a student centered inquiry based approach. Implications of using this model as a powerful means of professional development for science teachers are explored.  相似文献