2,596 research outputs found

    CONTEST : a Controllable Test Matrix Toolbox for MATLAB

    Get PDF
    Large, sparse networks that describe complex interactions are a common feature across a number of disciplines, giving rise to many challenging matrix computational tasks. Several random graph models have been proposed that capture key properties of real-life networks. These models provide realistic, parametrized matrices for testing linear system and eigenvalue solvers. CONTEST (CONtrollable TEST matrices) is a random network toolbox for MATLAB that implements nine models. The models produce unweighted directed or undirected graphs; that is, symmetric or unsymmetric matrices with elements equal to zero or one. They have one or more parameters that affect features such as sparsity and characteristic pathlength and all can be of arbitrary dimension. Utility functions are supplied for rewiring, adding extra shortcuts and subsampling in order to create further classes of networks. Other utilities convert the adjacency matrices into real-valued coefficient matrices for naturally arising computational tasks that reduce to sparse linear system and eigenvalue problems

    Multiple Access Protocols for Data Communications via VSAT Networks

    Get PDF
    One of the most significant advantages of VSAT Networks is the ability to link together many terminals at remote sites under a single manageable network and to adapt the performance characteristics of the network to the requirements of the type of data traffic presented to the network

    Export Tourism Input-Output Multipliers for Ireland. Quarterly Economic Commentary Special Article, May 1982

    Get PDF
    This paper focuses on some difficulties involved in the interpretation of earlier studies and goes on to calculate upper bound estimates of some of the principal economic effects of Irish export tourism in 1976. The 1976 input-output data of Henry (1980) form the basis for the calculations herein

    Optic neuropathy associated with systemic sarcoidosis

    Get PDF
    Objective: To identify and follow a series of 52 patients with optic neuropathy related to sarcoidosis. Methods: Prospective observational cohort study. Results: The disorder was more common in women and affected a wide age range. It was proportionately more common in African and Caribbean ethnic groups. Two clinical subtypes were identified: the more common was a subacute optic neuropathy resembling optic neuritis; a more slowly progressive optic neuropathy arose in the remaining 17%. Sixteen (31%) were bilateral. Concurrent intraocular inflammation was seen in 36%. Pain arose in only 27% of cases. An optic perineuritis was seen in 2 cases, and predominate involvement of the chiasm in one. MRI findings showed optic nerve involvement in 75% of cases, with adjacent and more widespread inflammation in 31%. Treatment with corticosteroids was helpful in those with an inflammatory optic neuropathy, but not those with mass lesions. Relapse of visual signs arose in 25% of cases, necessitating an increase or escalation of treatment, but relapse was not a poor prognostic factor. Conclusions: This is a large prospective study of the clinical characteristics and outcome of treatment in optic neuropathy associated with sarcoidosis. Patients who experience an inflammatory optic neuropathy respond to treatment but may relapse. Those with infiltrative or progressive optic neuropathies improve less well even though the inflammatory disorder responds to therapy

    Autoantibodies to Hair Follicles in C3H/HeJ Mice With Alopecia Areata–Like Hair Loss

    Get PDF
    We have previously described spontaneous but reversible hair loss that clinically and histologically resembles human alopecia areata in a colony of C3H/HeJ mice. Alopecia areata in humans is associated with antibodies to hair follicles. This study was conducted to determine whether C3H/HeJ mice with hair loss have a similar abnormal antibody response to hair follicles. Eighteen C3H/HeJ mice with alopecia, 12 unaffected littermates, and 15 control mice were examined for circulating antibodies to C3H/HeJ anagen hair follicles by indirect immunofluorescence and against extracts of isolated C3H/HeJ and human anagen hair follicles by immunoblotting. Using both procedures, antibodies to anagen hair follicles were present in all C3H/HeJ mice with alopecia but in none of the control mice. The antibodies were also present in some unaffected C3H/HeJ littermates but were absent in mice of an unrelated strain with inflammatory skin disease and alopecia, indicating that their appearance did not result from the hair loss. These antibodies reacted to hair follicle–specific antigens of 40–60kDa present in murine and human anagen hair follicles. These antigens were also reactive with human alopecia areata antibodies. Some of the antibodies in both C3H/HeJ mice and humans with alopecia areata reacted to antigens of 44 and 46 kDa, which were identified as hair follicle–specific keratins. This study indicates that C3H/HeJ mice with hair loss have circulating antibodies to hair follicles similar to those present in humans with alopecia areata. These findings confirm that these mice are an appropriate model for human alopecia areata and support the hypothesis that alopecia areata results from an abnormal autoimmune response to hair follicles

    Fostering Self-Authorship and Changemaking: Insights from a Social Entrepreneurship Practicum

    Get PDF
    The question we are explore in this paper is how a collaboration between a practicum-based course and a social enterprise encourages students to examine, discuss, and apply complex social justice concepts and frameworks. We also investigate how this fosters in them a sense of self as changemaker, a form of self-authorship that includes the confidence to tackle justice issues in collaborative and practical ways. Applying the framing of Baxter Magolda’s Learning Partnerships Model, we first describe our experiential pedagogical practice and then illustrate outcomes by drawing exemplars from student reflections. These reflections confirm that a community-based learning practice can support students to become changemakers able to analyze the systemic forces that give rise to injustices, engage in honest dialogue to understand multiple perspectives, cultivate trusting relationships across differences of identity and experience, and feel confidence in themselves and others to create meaningful change toward a more just world

    Organic-Silica Interactions in Saline:Elucidating the Structural Influence of Calcium in Low-Salinity Enhanced Oil Recovery

    Get PDF
    Abstract Enhanced oil recovery using low-salinity solutions to sweep sandstone reservoirs is a widely-practiced strategy. The mechanisms governing this remain unresolved. Here, we elucidate the role of Ca2+ by combining chemical force microscopy (CFM) and molecular dynamics (MD) simulations. We probe the influence of electrolyte composition and concentration on the adsorption of a representative molecule, positively-charged alkylammonium, at the aqueous electrolyte/silica interface, for four electrolytes: NaCl, KCl, MgCl2, and CaCl2. CFM reveals stronger adhesion on silica in CaCl2 compared with the other electrolytes, and shows a concentration-dependent adhesion not observed for the other electrolytes. Using MD simulations, we model the electrolytes at a negatively-charged amorphous silica substrate and predict the adsorption of methylammonium. Our simulations reveal four classes of surface adsorption site, where the prevalence of these sites depends only on CaCl2 concentration. The sites relevant to strong adhesion feature the O− silica site and Ca2+ in the presence of associated Cl−, which gain prevalence at higher CaCl2 concentration. Our simulations also predict the adhesion force profile to be distinct for CaCl2 compared with the other electrolytes. Together, these analyses explain our experimental data. Our findings indicate in general how silica wettability may be manipulated by electrolyte concentration

    Neuroimaging evidence implicating cerebellum in support of sensory/cognitive processes associated with thirst.

    Get PDF
    Recent studies implicate the cerebellum, long considered strictly a motor control structure, in cognitive, sensory, and affective phenomenon. The cerebellum, a phylogenetically ancient structure, has reciprocal ancient connections to the hypothalamus, a structure important in vegetative functions. The present study investigated whether the cerebellum was involved in vegetative functions and the primal emotions engendered by them. Using positron emission tomography, we examined the effects on the cerebellum of the rise of plasma sodium concentration and the emergence of thirst in 10 healthy adults. The correlation of regional cerebral blood flow with subjects' ratings of thirst showed major activation in the vermal central lobule. During the development of thirst, the anterior and posterior quadrangular lobule, lingula, and the vermis were activated. At maximum thirst and then during irrigation of the mouth with water to alleviate dryness, the cerebellum was less activated. However, 3 min after drinking to satiation, the anterior quadrangular lobule and posterior cerebellum were highly activated. The increased cerebellar activity was not related to motor behavior as this did not occur. Instead, responses in ancient cerebellar regions (vermis, fastigal nucleus, archicerebellum) may be more directly related to vegetative and affective aspects of thirst experiences, whereas activity in neocerebellar (posterior) regions may be related to sensory and cognitive aspects. Moreover, the cerebellum is apparently not involved in the computation of thirst per se but rather is activated during changes in thirst/satiation state when the brain is "vigilant" and is monitoring its sensory systems. Some neocerebellar activity may also reflect an intentionality for gratification by drinking inherent in the consciousness of thirst

    Diseño de un instrumento de caracterización de rasgos de personalidad en agresores sexuales

    Get PDF
    Especial InterésEl objetivo del instrumento es brindar una medida de los rasgos de personalidad predominantes en los agresores sexuales. Gracias a la revisión teórica y empírica, se identificó que se encuentran similitudes en sus rasgos de personalidad, a partir de los cuales se proponen 4 rasgos principales: Narcisista, Obsesivo Compulsivo, Antisocial y Límite de la personalidad. El cuestionario está compuesto por 35 ítems, de tipo dicotómico, que definen los 4 rasgos mencionados, dirigido a población penitenciaria condenada por delito de Agresión Sexual.RESUMEN 1. JUSTIFICACIÓN 2. MARCO LEGAL 3. MARCO ÉTICO 4. OBJETIVOS 5. PRODUCTO VISIBLE 6. ESTUDIO DE MERCADEO 7. El PRODUCTO RESULTADOS DISCUSIÓNPregradoPsicólog

    Treatment evolution in high-risk congenital diaphragmatic hernia: ten years\u27 experience with diaphragmatic agenesis.

    Get PDF
    OBJECTIVE: The objective of this study was to evaluate the impact of newer therapies on the highest risk patients with congenital diaphragmatic hernia (CDH), those with agenesis of the diaphragm. SUMMARY BACKGROUND DATA: CDH remains a significant cause of neonatal mortality. Many novel therapeutic interventions have been used in these infants. Those children with large defects or agenesis of the diaphragm have the highest mortality and morbidity. METHODS: Twenty centers from 5 countries collected data prospectively on all liveborn infants with CDH over a 10-year period. The treatment and outcomes in these patients were examined. Patients were followed until death or hospital discharge. RESULTS: A total of 1,569 patients with CDH were seen between January 1995 and December 2004 in 20 centers. A total of 218 patients (14%) had diaphragmatic agenesis and underwent repair. The overall survival for all patients was 68%, while survival was 54% in patients with agenesis. When patients with diaphragmatic agenesis from the first 2 years were compared with similar patients from the last 2 years, there was significantly less use of ECMO (75% vs. 52%) and an increased use of inhaled nitric oxide (iNO) (30% vs. 80%). There was a trend toward improved survival in patients with agenesis from 47% in the first 2 years to 59% in the last 2 years. The survivors with diaphragmatic agenesis had prolonged hospital stays compared with patients without agenesis (median, 68 vs. 30 days). For the last 2 years of the study, 36% of the patients with agenesis were discharged on tube feedings and 22% on oxygen therapy. CONCLUSIONS: There has been a change in the management of infants with CDH with less frequent use of ECMO and a greater use of iNO in high-risk patients with a potential improvement in survival. However, the mortality, hospital length of stay, and morbidity in agenesis patients remain significant
    • …
    corecore