844 research outputs found

    Improved Memoryless RNS Forward Converter Based on the Periodicity of Residues

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    The residue number system (RNS) is suitable for DSP architectures because of its ability to perform fast carry-free arithmetic. However, this advantage is over-shadowed by the complexity involved in the conversion of numbers between binary and RNS representations. Although the reverse conversion (RNS to binary) is more complex, the forward transformation is not simple either. Most forward converters make use of look-up tables (memory). Recently, a memoryless forward converter architecture for arbitrary moduli sets was proposed by Premkumar in 2002. In this paper, we present an extension to that architecture which results in 44% less hardware for parallel conversion and achieves 43% improvement in speed for serial conversions. It makes use of the periodicity properties of residues obtained using modular exponentiation

    Prevalence of sulfate reducing bacteria in oral cavity: a narrative review

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    Sulphate is used as terminal electron acceptor for the respiration of sulphate reducing bacteria (SRB) forming a specialized group of microbes. SRB have been known to cause microbiologically induced corrosion by forming metallic sulfides and oxides in the process of their dissimilatory respiration. Since oral cavity provides a conducive environment for corrosion, presence of SRB in oral cavity and their corrosive potential needs to be assessed. This article provides a narrative review of the available literature with the primary objective of evaluating the presence of SRB in oral cavity of patients.Keywords: SRB; corrosion, oral cavity, patient

    Expression of Emerging Novel Tumor markers in Oral Squamous cell carcinoma and their Clinical and Pathological correlation to determine the Prognosis and Usefulness as a Therapeutic target: A Systematic Review

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    Background: Inspite of 1000s of novel tumor markers in past 2 decades there is not even a single tumor marker which is proved to have diagnostic or prognostic value in oral squamous cell carcinoma (OSCC). The purpose of this review is to examine the current status of the emerging novel tumor markers. Methods: This search strategy was in accordance with the Cochrane guidelines for systemic review. Articles were selected using Pubmed search. The article search included only those published in the English literature. Results: Total of 12 tumor markers were analyzed. None of the tumor markers analyzed has all the qualities for a tumor marker like good sensitivity, specificity for diagnosis or assessing the prognosis Conclusions: Thus far, studies, although inconclusive, have found that the likelihood of identifying a biomarker with such sensitivity and specificity may be slim, at least for the immediate future. Key words: oral squamous cell carcinoma, novel tumor marker

    Schizotypal traits and their relation to rejection sensitivity in the general population: the mediation by quality of life, agreeableness and neuroticism

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    Schizotypal traits are a cluster of personality styles suggesting a potential liability for schizophrenia-spectrum disorders. Rejection sensitivity is evident all along this continuum. This study aimed to determine whether the relation between schizotypy and rejection sensitivity was mediated by psychosocial quality of life (QOL), neuroticism and agreeableness. Three hundred and eighteen participants from a predominantly University student population completed an online survey measuring schizotypy, rejection sensitivity, quality of life, and the five-factor personality traits. A regression analysis determined the prediction of rejection sensitivity by the facets of the other variables. Analyses examined the mediation of the relation between interpersonal schizotypy and rejection sensitivity by psychological QOL, social QOL, neuroticism, and agreeableness. Interpersonal schizotypal traits were cognitive disorganisation which includes social anxiety, and introvertive anhedonia which includes a lack of pleasure in social activities. Interpersonal schizotypy predicted greater rejection sensitivity. Psychological QOL, social QOL, neuroticism, and agreeableness mediated the relation between interpersonal schizotypy and rejection sensitivity. To conclude, a higher level of interpersonal schizotypy relates to greater rejection sensitivity. This association is mediated by psychosocial factors that lower one’s ability to have positive feelings and trusting relationships, and personality traits that increase worrying and lower prosocial behaviour

    Comparative Effects of Heterologous TRPV1 and TRPM8 Expression in Rat Hippocampal Neurons

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    Heterologous channel expression can be used to control activity in select neuronal populations, thus expanding the tools available to modern neuroscience. However, the secondary effects of exogenous channel expression are often left unexplored. We expressed two transient receptor potential (TRP) channel family members, TRPV1 and TRPM8, in cultured hippocampal neurons. We compared functional expression levels and secondary effects of channel expression and activation on neuronal survival and signaling. We found that activation of both channels with appropriate agonist caused large depolarizing currents in voltage-clamped hippocampal neurons, exceeding the amplitude responses to a calibrating 30 mM KCl stimulation. Both TRPV1 and TRPM8 currents were reduced but not eliminated by 4 hr incubation in saturating agonist concentration. In the case of TRPV1, but not TRPM8, prolonged agonist exposure caused strong calcium-dependent toxicity. In addition, TRPV1 expression depressed synaptic transmission dramatically without overt signs of toxicity, possibly due to low-level TRPV1 activation in the absence of exogenous agonist application. Despite evidence of expression at presynaptic sites, in addition to somatodendritic sites, TRPM8 expression alone exhibited no effects on synaptic transmission. Therefore, by a number of criteria, TRPM8 proved the superior choice for control over neuronal membrane potential. This study also highlights the need to explore potential secondary effects of long-term expression and activation of heterologously introduced channels

    Copper Alloy-Impregnated Carbon-Carbon Hybrid Composites for Electronic Packaging Applications

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    Porous carbon-carbon preforms, based on three-dimensional networks of PAN (Polyacrylonitrile)-based carbon fibers and various volume fractions of chemical vapor-deposited (CVD) carbon, were impregnated by oxygen-free, high-conductivity (OFHC) Cu, Cu-6Si-0.9Cr, and Cu-0.3Si-0.3Cr (wt pct) alloys by pressure infiltration casting. The obtained composites were characterized for their coefficient of thermal expansion (CTE) and thermal conductivity (K) along the through-thickness and two in-plane directions. One composite, with a 28 vol pct Cu-0.3Si-0.3Cr alloy, showed outstanding potential for thermal management applications in electronic applications. This composite exhibited approximately isotropic thermal expansion properties (CTE = 4 to 6.5 ppm/K) and thermal conductivities (k greater than or equal to 260 W/m K)

    Neural changes following cognitive behaviour therapy for psychosis: a longitudinal study

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    A growing body of evidence demonstrates that persistent positive symptoms, particularly delusions, can be improved by cognitive behaviour therapy for psychosis. Heightened perception and processing of threat are believed to constitute the genesis of delusions. The present study aimed to examine functional brain changes following cognitive behaviour therapy for psychosis. The study involved 56 outpatients with one or more persistent positive distressing symptoms of schizophrenia. Twenty-eight patients receiving cognitive behaviour therapy for psychosis for 6–8 months in addition to their usual treatment were matched with 28 patients receiving treatment as usual. Patients’ symptoms were assessed by a rater blind to treatment group, and they underwent functional magnetic resonance imaging during an affect processing task at baseline and end of treatment follow-up. The two groups were comparable at baseline in terms of clinical and demographic parameters and neural and behavioural responses to facial and control stimuli. The cognitive behaviour therapy for psychosis with treatment-as-usual group (22 subjects) showed significant clinical improvement compared with the treatment-as-usual group (16 subjects), which showed no change at follow-up. The cognitive behaviour therapy for psychosis with treatment-as-usual group, but not the treatment-as-usual group, showed decreased activation of the inferior frontal, insula, thalamus, putamen and occipital areas to fearful and angry expressions at treatment follow-up compared with baseline. Reduction of functional magnetic resonance imaging response during angry expressions correlated directly with symptom improvement. This study provides the first evidence that cognitive behaviour therapy for psychosis attenuates brain responses to threatening stimuli and suggests that cognitive behaviour therapy for psychosis may mediate symptom reduction by promoting processing of threats in a less distressing way

    PhaseQuant: A tool for quantifying tomographic data sets of geological specimens

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    a b s t r a c t Micro-CT is becoming an increasingly important tool for non-destructive analysis of rock specimens. One of the major challenges with micro-CT is to extract quantitative information as opposed to qualitative information from the datasets. In this paper, PhaseQuant -a new software tool for processing a micro-CT image stack -is introduced. PhaseQuant is an open source freeware distributed as an ImageJ plugin. PhaseQuant is a simple and easy-to-use software tool that comprises phase segmentation, phase measurement, validation and density calibration modules which together enable the user to follow a repeatable experimentation protocol for quantifying phases and components from a micro-CT image stack of rock specimens. The techniques used in the software tool are outlined in this paper along with some illustrative examples of application of the software to meteorites and rock cores. Detailed instructions on how to use the code are available on the Internet
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