251 research outputs found

    Retinal processes involved in the evoked cortical potential to patterned stimuli

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    The purpose of this investigation was to study the underlying physiological processes involved in the evoked potential to patterned visual stimulation. Specifically, the study was designed to assess the role of the photopic and scotopic visual systems as mediatory processes subserving occipitally elicited potentials to a series of checkerboard patterns. In addition, it was hoped that the research would provide further information with respect to the hypothetical mechanisms of lateral inhibition and receptive field size and their contribution to complex visual processes. Six subjects participated in the experiment. Evoked potentials were recorded to a series of patterned stimuli that were illuminated with red and blue flashes presented to central and peripheral retinal sites against high and low levels of background luminance. Statistical analysis of the data revealed significant relations between evoked potential amplitude and the main effects of background, site, and check-size. Amplitude was also significantly related to the interaction effects of background x site, check-size x background, check-size x color, and site x color x background. Discussion of the results was in terms of the differential functional behavior of photopic and scotopic visual processes. Several comments were directed to the possible importance of lateral inhibition and receptive field size in the generation of these data

    Profile of Public Health Leadership

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    Teacher Preference Of Administrator’s Transformational Or Transactional Leadership Style: A Regression Study

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    This quantitative study determined the relationship between leadership dispositions and behaviors North Carolina teachers and school administrators deemed essential in leadership development and creating a positive school climate. North Carolina teachers and administrators among the chosen eight North Carolina School Districts were surveyed concerning Marzano's 21 responsibilities of school leaders. The quantitative method featured a cross-sectional survey to investigate how the administration's transformational or transactional dispositions were preferred and influenced the teacher's and administrator's perceptions of school climate. Binary logistic regression was employed to infer relationships between the dependent and independent variables in six models. Results showed significant relationships between predictor and criterion variables, including good school climate and preference for leadership styles. Implications for practice included several recommendations for school districts and their leaders. Further research recommendations also stemmed from this project to further examine variables and employ a phenomenological or narrative inquiry design to study several of the predictor variables that would not lend themselves to further quantitative analysis

    A parasite-derived 68-mer peptide ameliorates autoimmune disease in murine models of Type 1 diabetes and multiple sclerosis

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    © 2016 cThe Author(s). Helminth parasites secrete molecules that potently modulate the immune responses of their hosts and, therefore, have potential for the treatment of immune-mediated human diseases. FhHDM-1, a 68-mer peptide secreted by the helminth parasite Fasciola hepatica, ameliorated disease in two different murine models of autoimmunity, type 1 diabetes and relapsing-remitting immune-mediated demyelination. Unexpectedly, FhHDM-1 treatment did not affect the proliferation of auto-antigen specific T cells or their production of cytokines. However, in both conditions, the reduction in clinical symptoms was associated with the absence of immune cell infiltrates in the target organ (islets and the brain tissue). Furthermore, after parenteral administration, the FhHDM-1 peptide interacted with macrophages and reduced their capacity to secrete pro-inflammatory cytokines, such as TNF and IL-6. We propose this inhibition of innate pro-inflammatory immune responses, which are central to the initiation of autoimmunity in both diseases, prevented the trafficking of autoreactive lymphocytes from the periphery to the site of autoimmunity (as opposed to directly modulating their function per se), and thus prevented tissue destruction. The ability of FhHDM-1 to modulate macrophage function, combined with its efficacy in disease prevention in multiple models, suggests that FhHDM-1 has considerable potential as a treatment for autoimmune diseases

    Integrated Virtual Learning Environment for Cybersecurity (IVLE4C)

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    The authors are working to improve students’ understanding of and classroom experience with enterprise cybersecurity. Central to this effort is development of the Integrated Virtual Learning Environment for Cybersecurity (IVLE4C), a teaching and learning tool intended for use by both teachers and students. The authors are endeavoring to incorporate into IVLE4C best practices from the knowledge domains of education, model-based systems engineering, and cybersecurity. A modern digital enterprise is a large-scale, complex system of systems. Enterprise cybersecurity is a special subset of the larger knowledge domain that merits special consideration when instructing students who lack relevant work experience. This lack of work experience creates a gap in students’ knowledge about the structure, operation, and control of a modern digital enterprise. Our guiding precept – coined Greer’s Rule of Thumb – is that: it is impossible to defend what cannot be visualized and described. Therefore, it is essential to address the student enterprise knowledge gap before attempting to teach the means for assuring enterprise cybersecurity. Viste and Skartveit (2004) propose using an interactive virtual learning environment with reality abstraction models when teaching the structure, operation, and control of a large-scale complex system. The creation of a virtual model enables a modern digital enterprise to be brought into the classroom. This allows for learning that is complementary to experiential learning that occurs during an internship and, possibly, a viable alternative when internships are unavailable or come later in a curriculum path. Once developed, a library of models representing different digital enterprise types can be used to accelerate student enterprise cybersecurity education in a controlled classroom environment. During the presentation, the authors will provide an update on the use of model-based system engineering practices and how they are being integrated into IVLE4C for developing a tailored, enterprise risk management strategy. This approach is consistent with guidance provided in the NIST Cybersecurity Framework. Research shows model-based systems engineering is increasingly being used for developing engineered cybersecurity solutions. An example of this is research performed by Robles-Ramirez et.al. (2020) on the application of model-based Cybersecurity Engineering for Connected and Automated Vehicles. Key is the notion of turning a cyber-attack surface into a trust boundary at targeted levels. IVLE4C version 1.0 is currently being used to teach Cyber Supply Chain Security at UNCW. Version 2.0 is a dynamic data driven web application, that is being developed for teaching Enterprise Security

    A practical approach to vitamin and mineral supplementation in food allergic children

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    The management of food allergy in children requires elimination of the offending allergens, which significantly contribute to micronutrient intake. Vitamin and mineral supplementation are commonly suggested as part of dietary management. However a targeted supplementation regime requires a complete nutritional assessment, which includes food diaries. Ideally these should be analysed using a computerised program, but are very time consuming. We therefore set out to evaluate current practice of vitamin and mineral supplementation in a cohort of children with non-Immunoglobulin E (IgE) mediated food allergies

    Hox10 Genes Function in Kidney Development in the Differentiation and Integration of the Cortical Stroma

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    Organogenesis requires the differentiation and integration of distinct populations of cells to form a functional organ. In the kidney, reciprocal interactions between the ureter and the nephrogenic mesenchyme are required for organ formation. Additionally, the differentiation and integration of stromal cells are also necessary for the proper development of this organ. Much remains to be understood regarding the origin of cortical stromal cells and the pathways involved in their formation and function. By generating triple mutants in the Hox10 paralogous group genes, we demonstrate that Hox10 genes play a critical role in the developing kidney. Careful examination of control kidneys show that Foxd1-expressing stromal precursor cells are first observed in a cap-like pattern anterior to the metanephric mesenchyme and these cells subsequently integrate posteriorly into the kidney periphery as development proceeds. While the initial cap-like pattern of Foxd1-expressing cortical stromal cells is unaffected in Hox10 mutants, these cells fail to become properly integrated into the kidney, and do not differentiate to form the kidney capsule. Consistent with loss of cortical stromal cell function, Hox10 mutant kidneys display reduced and aberrant ureter branching, decreased nephrogenesis. These data therefore provide critical novel insights into the cellular and genetic mechanisms governing cortical cell development during kidney organogenesis. These results, combined with previous evidence demonstrating that Hox11 genes are necessary for patterning the metanephric mesenchyme, support a model whereby distinct populations in the nephrogenic cord are regulated by unique Hox codes, and that differential Hox function along the AP axis of the nephrogenic cord is critical for the differentiation and integration of these cell types during kidney organogenesis
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