506 research outputs found

    On non-definite Sturm-Liouville problems with two turning points

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    This is an inaugural study of the Dirichlet problem associated with a regular non-definite Sturm-Liouville equation in the case of two turning points. We give a priori lower bounds on the Richardson numbers associated with this problem thereby complementing pioneering results by Atkinson and Jabon (1984) in the one turning point caseComment: 13 pages, To appear in Applied Math. and Computatio

    Frequency of the 7q11.23 inversion polymorphism in transmitting parents of children with Williams syndrome and in the general population does not differ between North America and Europe

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    Inversion of the Williams syndrome (WS) region on chromosome 7q11.23 has previously been shown to occur at a higher frequency in the transmitting parents of children with WS than in the general population, suggesting that it predisposes to the WS deletion. Frohnauer et al. recently reported that the frequency of this inversion is not elevated in the parents of children with WS in Germany relative to the German general population. We have compared Frohnauer et al.'s data to those from three previously published studies (Hobart et al., Bayes et al., Osborne et al.), all of which reported a significantly higher rate of 7q11.23 inversion in transmitting parents than in the general population. Results indicated that Frohnauer et al.'s data are consistent with previously reported frequencies of 7q11.23 inversion in North America and Spain in both transmitting parents and the general population

    Pragmatic Abilities of Children with Williams Syndrome: A Longitudinal Examination

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    Prior research has indicated that pragmatics is an area of particular weakness for individuals with Williams syndrome (WS). To further address this aspect of the WS social phenotype, we used an individual differences approach to consider both cross-sectional and longitudinal relations among different pragmatic abilities for 14 children with WS, taking into account individual differences in non-verbal reasoning abilities. We also considered the relations between pragmatic abilities and expressive vocabulary ability. Participants were tested at two time points: as 4-year-olds during a 30-min play session with their mothers (Time 1) and an average of 5.87 years later during a one-on-one conversation with a familiar researcher (Time 2). Children’s intellectual and expressive vocabulary abilities were assessed at both time points. Results indicated that the ability to verbally contribute information beyond what was required in response to a question (ExtendQ) was significantly related to the ability to verbally contribute new information in the absence of a question (ExtendS) both at age 4 years and during primary school. At age 4, both the ability to pair verbalizations with eye contact in triadic interactions (secondary intersubjectivity) and expressive vocabulary ability were related to both ExtendQ and ExtendS. Finally, both ExtendQ and the ability to pair verbalizations with eye contact (intersubjectivity) at age 4 years predicted ExtendQ at age 9–12 years. The theoretical implications of our findings and the importance of early pragmatic language intervention for children who have WS are discussed

    Neurobiology of social behavior abnormalities in autism and Williams syndrome

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    Social behavior is a basic behavior mediated by multiple brain regions and neural circuits, and is crucial for the survival and development of animals and humans. Two neuropsychiatric disorders that have prominent social behavior abnormalities are autism spectrum disorders (ASD), which is characterized mainly by hyposociability, and Williams syndrome (WS), whose subjects exhibit hypersociability. Here we review the unique properties of social behavior in ASD and WS, and discuss the major theories in social behavior in the context of these disorders. We conclude with a discussion of the research questions needing further exploration to enhance our understanding of social behavior abnormalities

    A meta-analysis and critical review of prospective memory in autism spectrum disorder

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    Prospective memory (PM) is the ability to remember to carry out a planned intention at an appropriate moment in the future. Research on PM in ASD has produced mixed results. We aimed to establish the extent to which two types of PM (event-based/time-based) are impaired in ASD. In part 1, a meta-analysis of all existing studies indicates a large impairment of time-based, but only a small impairment of event-based, PM in ASD. In Part 2, a critical review concludes that time-based PM appears diminished in ASD, in line with the meta-analysis, but that caution should be taken when interpreting event-based PM findings, given potential methodological limitations of several studies. Clinical implications and directions for future research are discussed

    Use of spelling rules in school-aged children with Williams syndrome

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    Purpose: Researchers evaluating children’s spelling abilities usually score their spellings dichotomously - as correct or incorrect. This type of scoring is not as informative as procedures that take into consideration the plausibility of children’s spellings (Treiman et al., 2016). We examined the spelling abilities of children and adolescents with Williams syndrome (WS), a genetic disorder associated with intellectual disability, to determine if their spellings were based on English orthographic rules. Method: Sixty-six 9–17-year-olds with WS (M=13.50 years, SD=3.14) completed the Wechsler Individual Achievement Test-III (Wechsler, 2009) Spelling subtest. Items 6 to 16 were scored using the Ponto software (Kessler, 2017) to determine the extent to which children’s spelling differed from the correct spelling (the “letter distance ). Letter distance is calculated based on the transformations needed to change the child’s spelling to the correct spelling. Each insertion or deletion is scored 1, and each substitution is scored 1.4. If the word is spelled correctly, its letter distance is 0. Letter distance scores for the child’s spellings were compared to letter distance scores for random spellings, using the Monte Carlo method. Improvement scores were obtained by dividing a child’s sum of letter distances by the sum of random letter distances. Results: Children spelled a median of 10 (MAD=1) of 11 words correctly. Their mean improvement score was 0.89 (SD=0.14), which was significantly better than expected if their spelling had been random, p \u3c .001. Conclusion: Children and adolescents with WS have at least some knowledge of English orthographic spelling rules.https://ir.library.louisville.edu/uars/1054/thumbnail.jp

    Cognitive frames in corporate sustainability: managerial sensemaking with paradoxical and business case frames

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    Corporate sustainability confronts managers with tensions between complex economic, environmental, and social issues. Drawing on the literature on managerial cognition, corporate sustainability, and strategic paradoxes, we develop a cognitive framing perspective on corporate sustainability. We propose two cognitive frames—a business case frame and a paradoxical frame—and explore how differences between them in cognitive content and structure influence the three stages of the sensemaking process—that is, managerial scanning, interpreting, and responding with regard to sustainability issues. We explain how the two frames lead to differences in the breadth and depth of scanning, differences in issue interpretations in terms of sense of control and issue valence, and different types of responses that managers consider with regard to sustainability issues. By considering alternative cognitive frames, our argument contributes to a better understanding of managerial decision making regarding ambiguous sustainability issues, and it develops the underlying cognitive determinants of the stance that managers adopt on sustainability issues. This argument offers a cognitive explanation for why managers rarely push for radical change when faced with complex and ambiguous issues, such as sustainability, that are characterized by conflicting yet interrelated aspects

    An Initiative to Broaden Diversity in Undergraduate Biomathematics Training

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    At North Carolina A&T State University (NCATSU), there was a critical need to better coordinate genuine research and classroom experiences for undergraduates early in their academic career. We describe the development and implementation of a faculty alliance across academic departments to increase biomathematics research opportunities for underrepresented minorities. Our faculty alliance is called the Integrative Biomathematical Learning and Empowerment Network for Diversity (iBLEND). The fundamental purpose of the iBLEND alliance was to inspire underrepresented minorities to pursue research careers by increasing the visibility of research conducted at the interface of mathematics and biology at NCATSU. Because of the many positive impacts, iBLEND gained significant buy-in from administration, faculty, and students by 1) working from the ground up with administration to promote campus-wide biomathematics research and training, 2) fostering associations between research and regular undergraduate academic courses, 3) creating and disseminating biomathematics teaching and learning modules, and 4) enhancing learning community support at the interface of mathematics and biology. Currently, iBLEND is viewed as a productive site for graduate schools to recruit underrepresented minority students having specific competencies related to mathematical biology

    Genome Rearrangements Detected by SNP Microarrays in Individuals with Intellectual Disability Referred with Possible Williams Syndrome

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    Intellectual disability (ID) affects 2-3% of the population and may occur with or without multiple congenital anomalies (MCA) or other medical conditions. Established genetic syndromes and visible chromosome abnormalities account for a substantial percentage of ID diagnoses, although for approximately 50% the molecular etiology is unknown. Individuals with features suggestive of various syndromes but lacking their associated genetic anomalies pose a formidable clinical challenge. With the advent of microarray techniques, submicroscopic genome alterations not associated with known syndromes are emerging as a significant cause of ID and MCA.High-density SNP microarrays were used to determine genome wide copy number in 42 individuals: 7 with confirmed alterations in the WS region but atypical clinical phenotypes, 31 with ID and/or MCA, and 4 controls. One individual from the first group had the most telomeric gene in the WS critical region deleted along with 2 Mb of flanking sequence. A second person had the classic WS deletion and a rearrangement on chromosome 5p within the Cri du Chat syndrome (OMIM:123450) region. Six individuals from the ID/MCA group had large rearrangements (3 deletions, 3 duplications), one of whom had a large inversion associated with a deletion that was not detected by the SNP arrays.Combining SNP microarray analyses and qPCR allowed us to clone and sequence 21 deletion breakpoints in individuals with atypical deletions in the WS region and/or ID or MCA. Comparison of these breakpoints to databases of genomic variation revealed that 52% occurred in regions harboring structural variants in the general population. For two probands the genomic alterations were flanked by segmental duplications, which frequently mediate recurrent genome rearrangements; these may represent new genomic disorders. While SNP arrays and related technologies can identify potentially pathogenic deletions and duplications, obtaining sequence information from the breakpoints frequently provides additional information
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