168 research outputs found

    Phase transition in multi-scalar-singlet extensions of the Standard Model

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    We propose a generalization of the Standard Model (SM) by adding two real gaugesinglets S1, S2. The field S1 will improve the strength of the electroweak phase transition (EWPT). Imposing a Z2 symmetry on the field S2 makes this field a possible candidate for dark matter. Both singlets interact with other observable fields through Higgs boson. They are allowed to interact with each other as well. We find that by introducing two different scalar fields, the model is less vulnerable to experimental constraints. In this paper, we consider the effects of a heavy scalar(M1 > MH) on the electroweak phase transition. And we present configurations that produce a strong first order EWPT

    Hand Pointing Detection Using Live Histogram Template of Forehead Skin

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    Hand pointing detection has multiple applications in many fields such as virtual reality and control devices in smart homes. In this paper, we proposed a novel approach to detect pointing vector in 2D space of a room. After background subtraction, face and forehead is detected. In the second step, forehead skin H-S plane histograms in HSV space is calculated. By using these histogram templates of users skin, and back projection method, skin areas are detected. The contours of hand are extracted using Freeman chain code algorithm. Next step is finding fingertips. Points in hand contour which are candidates for the fingertip can be found in convex defects of convex hull and contour. We introduced a novel method for finding the fingertip based on the special points on the contour and their relationships. Our approach detects hand-pointing vectors in live video from a common webcam with 94%TP and 85%TN.Comment: Accepted for oral presentation in DSP201

    Generation of Free Carriers in MoSe2 Monolayers Via Energy Transfer from CsPbBr3 Nanocrystals

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    Transition metal dichalcogenide (TMDCs) monolayers make an excellent component in optoelectronic devices such as photodetectors and phototransistors. Selenide-based TMDCs, specifically molybdenum diselenide (MoSe2) monolayers with low defect densities, show much faster photoresponses compared to their sulfide counterpart. However, the typically low absorption of the atomically thin MoSe2 monolayer and high exciton binding energy limit the photogeneration of charge carriers. Yet, integration of light-harvesting materials with TMDCs can produce increased photocurrents via energy transfer. In this article, it is demonstrated that the interaction of cesium lead bromide (CsPbBr3) nanocrystals with MoSe2 monolayers results into an energy transfer efficiency of over 86%, as ascertained from the quenching and decay dynamics of the CsPbBr3 nanocrystals emission. Notably, the increase in the MoSe2 monolayer emission in the heterostructure accounts only for 33% of the transferred energy. It is found that part of the excess energy generates directly free carriers in the MoSe2 monolayer, as a result of the transfer of energy into the exciton continuum. The efficiency of the heterostructure via enhanced photocurrents with respect to the single material unit is proven. These results demonstrate a viable route to overcome the high exciton binding energy typical for TMDCs, as such having an impact on optoelectronic processes that rely on efficient exciton dissociation

    Angiotensin enzyme inhibitors and angiotensin receptor blockers as protective factors in COVID-19 mortality: a retrospective cohort study

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    Targeting the renin-angiotensin system is proposed to affect mortality due to coronavirus disease 2019 (COVID-19). We aimed to compare the mortality rates in COVID-19 patients who received angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (ACEIs/ARBs) and those who did not. In this retrospective cohort study, mortality was considered as the main outcome measure. All underlying diseases were assessed by the chronic use of medications related to each condition. We defined two main groups based on the ACEIs/ARBs administration. A logistic regression model was designed to define independent predictors of mortality as well as a Cox regression analysis. In total, 2553 patients were included in this study. The mortality frequency was higher in patients with a history of underlying diseases (22.4 vs 12.7, P value < 0.001). The mortality rate in patients who received ACEIs/ARBs were higher than non-receivers (29.3 vs. 19.5, P value = 0.013, OR = 1.3, 95 CI 1.1, 1.7) in the univariate analysis. However, the use of ACEIs/ARBs was a protective factor against mortality in the model when adjusted for underlying conditions, length of stay, age, gender, and ICU admission (P value < 0.001, OR = 0.5, 95 CI 0.3, 0.7). The Kaplan�Meier curve showed an overall survival of approximately 85.7 after a 120-day follow-up. ACEIs/ARBs are protective factors against mortality in COVID-19 patients with HTN, and these agents can be considered potential therapeutic options in this disease. The survival probability is higher in ACEIs/ARBs receivers than non-receivers. © 2020, Società Italiana di Medicina Interna (SIMI)

    Novel VIPAS39 mutation in a syndromic patient with arthrogryposis, renal tubular dysfunction and intrahepatic cholestasis

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    ARC syndrome is a rare autosomal recessive disease, characterized by arthrogryposis, renal tubular dysfunction and cholestasis. Herein a 2.5 month old infant with dysmorphic features, including small anterior fontanel, low set ears, beaked nose and high arched palate is presented who was referred because of icterus. He also suffered from some additional anomalies, including unilateral choanal atresia, club foot, and bilateral developmental dislocation of hip, while further studies showed renal tubular acidosis and hearing impairment in addition to cholestasis. Genetic studies showed a homozygous mutation in the VIPAS39 gene. Making the definite diagnosis of the syndrome is important, while increased risk of mutation in other siblings highlights the importance of prenatal diagnosis

    A longitudinal analysis of motivation profiles at work

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    This paper examines the multidimensional nature of workplace motivation and the importance of a continuum structure in self-determination theory through application of complementary variable- and person-centered approaches. This approach is taken to simultaneously model the complexity of motivation and highlight interactions between motivational factors. Additionally, this study represents an initial test of the temporal stability of work motivation profiles. A sample of 510 full-time employees were recruited from a range of occupations. Results support the central importance of a general factor representing self-determination as the most influential factor in an employee’s motivation profile. However, smaller effects associated with the motivation subscales, especially identified regulation, were also noticed. Importantly, motivation profiles were found to be highly stable over the 4-month duration of this study. Results lend support to the theoretical position that while general self-determination is an essential component of motivation, it alone does not fully describe an employee’s motivation
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