Adaptive synchronization of chaotic Colpitts circuits against parameter mismatches and channel distortions

In this work, synchronization of chaotic Colpitts circuits, using adaptive controllers to combat circuit parameter mismatches and channel distortions, is studied by numerical simulations. Synchronization errors caused by different main circuit components are compared, and compensation for time-constant and time-varying circuit parameter mismatches is demonstrated. Different kinds of channel distortions, including time-constant and time-varying channel attenuation, Additive White Gaussian Noise (AWGN) are all investigated by numerical simulations and discussed. Simulation results indicated that the synchronization performance of chaotic Colpitts circuits can be greatly improved by applying adaptive controllers when parameter mismatches and channel attenuation are considered as time-constant or time-varying, but have no obvious enhancements regarding the effect on AWGN channel.     

Identifying correlates of reabuse in maltreating parents

Forty-five abusive parents (40 mothers, 5 fathers) in treatment at a large, urban medical center's child abuse program were compared on 22 parent, child, and treatment variables posited to bear on reabuse. While no one variable by itself was strongly associated with reabuse, the data indicated that interactions involving several variables (e.g., income source, marital status, and the abuser's personal abuse history) significantly differentiated between reabusers and nonreabusers. Implications of the findings for research and clinical intervention are discussed.     

Understanding autonomous peer feedback practices among postgraduate students: a case study in a Chinese university

Academic writing is a social practice in which the writer interacts with both texts and people and uses the interaction as a learning resource. While academic interaction in the classroom setting has been extensively investigated, student interaction that takes place without teacher supervision remains largely unexplored. Since autonomy is a key component of academic interaction, autonomous peer feedback practices among postgraduate students may be of some interest. This paper reports on an exploratory case study of peer feedback among a small group of postgraduate students in a master’s programme in translation studies in a prestigious Chinese university. The findings offer insights into the role of peer feedback in advancing academic literacy and forming scholarly communities in an emerging discipline. The case study provides an opening into the research area of autonomous peer feedback and suggests avenues for further, more substantial research.     

Determinants of placement for sexually abused children

While conducting a prospective study of 100 sexually abused children, we found a much higher rate of out-of-home placement than has been previously described for child maltreatment. This study was designed to determine which factors were most influential in predicting the placement experiences of this cohort. The children, ages 6-17 years, were recently substantiated victims of intrafamilial sexual abuse whose parents or guardians permitted study involvement. We examined child and family demographics, abuse characteristics, and family response as possible determinants of immediate and later placement. At the initial assessment, within a few weeks of the disclosure, 50% of the children had already been removed. A follow-up assessment of 83 children two years later revealed that 73% had been removed from the abusing home. In a multivariate regression model, only maternal support of the child emerged as a significant predictor of immediate placement and placement over time. The offender's status as a resident in the child's home was an important predictor of immediate placement but was not significant as a predictor of all placements at any time. As maternal support is an important predictor of the need for placement, workers are encouraged to seek ways of enhancing maternal support as a means of reducing placement.     

The effect of language specific factors on early written composition: the role of spelling,oral language and text generation skills in a shallow orthography

Spelling skills have been identified as one of the major barriers to written text production in young English writers. By contrast oral language skills and text generation have been found to be less influential in the texts produced by beginning writers. To date, our understanding of the role of spelling skills in transparent orthographies is limited. The current study addressed this gap by examining the contribution of spelling, oral language and text generation skills in written text production in Italian beginner writers. Eighty-three children aged 7–8 years participated in the study. Spelling, lexical retrieval, receptive grammar, and written sentence generation and reformulation skills were assessed and children were asked to write a text on a set topic. A factor analysis revealed that the children’s written text production was captured by three factors: productivity, complexity and accuracy. In contrast to results from children learning to write in opaque orthographies, such as English, this study showed that receptive grammar and written sentence generation skills accounted for significant variance in measures of productivity, complexity and accuracy in Italian children’s written text production. Spelling skills contributed to text accuracy and quality and explained more variance than receptive grammar in microstructural accuracy. By contrast, oral grammatical skills explained more variance in text quality than spelling. The current study shows the differential impact of language systems, such as Italian, on written text production. Implications for assessment and instruction are outlined.     

College Students’ Reasons for Depression Nondisclosure in Primary Care

Unwillingness to share depression experiences with primary care physicians contributes to the undertreatment of depression. This project examined college students’ reasons for depression nondisclosure to primary care providers (PCPs). Undergraduate participants read a vignette describing someone with depression and completed measures of disclosure barriers. Analyses indicated 26% of respondents would NOT disclose depression symptoms to PCPs. Reasons for nondisclosure included difficulty initiating the depression conversation, medication aversion, and fear of referral to a psychologist. Also, anger toward the vignette character varied with disclosure willingness, suggesting that nondisclosers feel more stigma than disclosers and are less likely to engage in psychotherapy. Because engagement in pharmacological and/or psychotherapeutic treatment requires identification of depression in healthcare settings, increased understanding of disclosure barriers could increase students’ access to depression treatment.