763 research outputs found

    An Analysis of Auditory Stimulus Generalization Gradients in Children with Autism Following Two Different Training Procedures

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    Previous research suggests learning of children with autism often fails to successfully generalize across changes in settings and stimuli. Much of this research has assessed generalization by first teaching a behavior in one context and then measuring the transfer of the behavior to extra-treatment stimuli and settings. The present study measured generalization of learned behavior by systematically varying the tone of an auditory stimulus present during training to obtain generalization gradients. Generalization gradients are graphical representations of the strength of a response produced by stimuli that vary from the training stimulus along some stimulus dimension. By obtaining generalization gradients, this research may offer a more precise means of characterizing the extent of generalization and the basic processes underlying it. The study also went beyond previous research with children with autism by examining the effects of two different training procedures upon the resulting generalization gradients. Participants were first taught to discriminate between the presence and absence of a specific stimulus, and later, to discriminate between two stimuli varied along the same dimension. Gradients were measured following both trainings. In the first training procedure, three children with autism were taught to engage in a simple communicative request in the presence of a specific tone and to withhold the request when there was no tone. The researchers then measured the extent to which these children continued to engage in the request as the tone was changed in frequency. They graphed the resulting data in the form of a generalization gradient. Although the shape of resulting generalization gradients differed between participants, all three participants in the present study showed a pattern of responding consistent with generalization. Gradients for two of three participants were orderly and decremental. In the second training procedure participants were taught to discriminate between two tones of different frequencies. Generalization gradients were again obtained. Predictable changes in the shape of gradients, consistent with basic research on generalization gradients, were noted for two of three participants. Results are discussed with regard to stimulus control, the behavioral processes of reinforcement and extinction, and what has been called the peak shift effect

    Studi dan Analisa Arc Flash dalam Menentukan Kategori PPE di Gardu Induk Teluk Lembu PT. PLN dengan Menggunakan Software ETAP 7.0.0

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    Arc Flash is dangerous happening in electric industry system. The cause of the damaged could be from a mistake of the system or maintenance procedur. Arc flash can broken tools and death of the workers around them. In order for our safety, we have to really take care of this system to avoid the damage and the life our workers. In this project, we will learn and make a research more and get throught it, we will learn about arc flash in Gardu Induk Teluk Lembu PT. PLN Pekanbaru. This study will teach us about how to count of arc flash with the standart of it an place the right category PPE

    Addressing key issues in the consanguinity-related risk of autosomal recessive disorders in consanguineous communities: lessons from a qualitative study of British Pakistanis

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    Currently there is no consensus regarding services required to help families with consanguineous marriages manage their increased genetic reproductive risk. Genetic services for communities with a preference for consanguineous marriage in the UK remain patchy, often poor. Receiving two disparate explanations of the cause of recessive disorders (cousin marriage and recessive inheritance) leads to confusion among families. Further, the realisation that couples in non-consanguineous relationships have affected children leads to mistrust of professional advice. British Pakistani families at-risk for recessive disorders lack an understanding of recessive disorders and their inheritance. Such an understanding is empowering and can be shared within the extended family to enable informed choice. In a three-site qualitative study of British Pakistanis, we explored family and health professional perspectives on recessively inherited conditions. Our findings suggest, first, that family networks hold strong potential for cascading genetic information, making the adoption of a family centred approach an efficient strategy for this community. However, this is dependent on provision of high quality and timely information from health care providers. Secondly, families’ experience was of ill-coordinated and time-starved services, with few having access to specialist provision from Regional Genetics Services; these perspectives were consistent with health professionals’ views of services. Thirdly, we confirm previous findings that genetic information is difficult to communicate and comprehend, further complicated by the need to communicate the relationship between cousin marriage and recessive disorders. A communication tool we developed and piloted is described and offered as a useful resource for communicating complex genetic information

    Induction of autoantibodies against lung matrix proteins and smoke-induced inflammation in mice

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    <p>Abstract</p> <p>Background</p> <p>Smoking is the major etiologic factor in COPD, yet the exact underlying pathogenetic mechanisms have not been elucidated. Since a few years, there is mounting evidence that a specific immune response, partly present as an autoimmune response, contributes to the pathogenesis of COPD. Increased levels of anti-Hep-2 epithelial cell and anti-elastin autoantibodies as well as antibodies against airway epithelial and endothelial cells have been observed in COPD patients. Whether the presence of these autoantibodies contributes to the pathogenesis of COPD is unclear.</p> <p>Methods</p> <p>To test whether induction of autoantibodies against lung matrix proteins can augment the smoke-induced inflammatory response, we immunized mice with a mixture of the lung extracellular matrix (ECM) proteins elastin, collagen, and decorin and exposed them to cigarette smoke for 3 or 6 months. To evaluate whether the immunization was successful, the presence of specific antibodies was assessed in serum, and presence of specific antibody producing cells in spleen and lung homogenates. In addition, the presence of inflammatory cells and cytokines was assessed in lung tissue and emphysema development was evaluated by measuring the mean linear intercept.</p> <p>Results</p> <p>We demonstrated that both ECM immunization and smoke exposure induced a humoral immune response against ECM proteins and that ECM immunization itself resulted in increased macrophage numbers in the lung. The specific immune response against ECM proteins did not augment the smoke-induced inflammatory response in our model.</p> <p>Conclusions</p> <p>By demonstrating that smoke exposure itself can result in a specific immune response and that presence of this specific immune response is accompanied by an influx of macrophages, we provide support for the involvement of a specific immune response in the smoke-induced inflammatory response as can be seen in patients with COPD.</p

    A Hydrophobic Gate in an Ion Channel: The Closed State of the Nicotinic Acetylcholine Receptor

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    The nicotinic acetylcholine receptor (nAChR) is the prototypic member of the `Cys-loop' superfamily of ligand-gated ion channels which mediate synaptic neurotransmission, and whose other members include receptors for glycine, gamma-aminobutyric acid, and serotonin. Cryo-electron microscopy has yielded a three dimensional structure of the nAChR in its closed state. However, the exact nature and location of the channel gate remains uncertain. Although the transmembrane pore is constricted close to its center, it is not completely occluded. Rather, the pore has a central hydrophobic zone of radius about 3 A. Model calculations suggest that such a constriction may form a hydrophobic gate, preventing movement of ions through a channel. We present a detailed and quantitative simulation study of the hydrophobic gating model of the nicotinic receptor, in order to fully evaluate this hypothesis. We demonstrate that the hydrophobic constriction of the nAChR pore indeed forms a closed gate. Potential of mean force (PMF) calculations reveal that the constriction presents a barrier of height ca. 10 kT to the permeation of sodium ions, placing an upper bound on the closed channel conductance of 0.3 pS. Thus, a 3 A radius hydrophobic pore can form a functional barrier to the permeation of a 1 A radius Na+ ion. Using a united atom force field for the protein instead of an all atom one retains the qualitative features but results in differing conductances, showing that the PMF is sensitive to the detailed molecular interactions.Comment: Accepted by Physical Biology; includes a supplement and a supplementary mpeg movie can be found at http://sbcb.bioch.ox.ac.uk/oliver/download/Movies/watergate.mp

    A Multi-factor Authentication Method for Security of Online Examinations

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    Security of online examinations is the key to success of remote online learning. However, it faces many conventional and non-conventional security threats. Impersonation and abetting are rising non-conventional security threats, when a student invites a third party to impersonate or abet in a remote exam. This work proposed dynamic profile questions authentication to identify that the person taking an online test is the same who completed the course work. This is combined with remote proctoring to prevent students from taking help from a third party during exam. This research simulated impersonation and abetting attacks in remote online course and laboratory based control simulation to analyse the impact of dynamic profile questions and proctoring. The study also evaluated effectiveness of the proposed method. The findings indicate that dynamic profile questions are highly effective. The security analysis shows that impersonation attack was not successful

    MicroRNAs Associated with Chronic Mucus Hypersecretion in COPD Are Involved in Fibroblast-Epithelium Crosstalk

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    We recently identified microRNAs (miRNAs) associated with chronic mucus hypersecretion (CMH) in chronic obstructive pulmonary disease (COPD), which were expressed in both airway epithelial cells and fibroblasts. We hypothesized that these miRNAs are involved in communication between fibroblasts and epithelium, contributing to airway remodeling and CMH in COPD. Primary bronchial epithelial cells (PBECs) differentiated at the air–liquid interface, and airway fibroblasts (PAFs) from severe COPD patients with CMH were cultured alone or together. RNA was isolated and miRNA expression assessed. miRNAs differentially expressed after co-culturing were studied functionally using overexpression with mimics in mucus-expressing human lung A549 epithelial cells or normal human lung fibroblasts. In PBECs, we observed higher miR-708-5pexpression upon co-culture with fibroblasts, and miR-708-5p expression decreased upon mucociliary differentiation. In PAFs, let-7a-5p, miR-31-5p and miR-146a-5p expression was significantly increased upon co-culture. miR-708-5p overexpression suppressed mucin 5AC (MUC5AC) secretion in A549, while let-7a-5poverexpression suppressed its target gene COL4A1 in lung fibroblasts. Our findings suggest that let-7a-5p, miR-31-5p and miR-146a-5p may be involved in CMH via fibroblasts–epithelium crosstalk, including extracellular matrix gene regulation, while airway epithelial expression of miR-708-5p may be involved directly, regulating mucin production. These findings shed light on miRNA-mediated mechanisms underlying CMH, an important symptom in COPD
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