105 research outputs found

    Towards large genus asymptotics of intersection numbers on moduli spaces of curves

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    Effects of using Artemia urmiana enriched with N-3 HUFA in first feeding of rainbow trout (Oncorhynchus mykiss) larvae

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    Effects of using n-3 HUFA-enriched Artemia and non-enriched Artemia as the starter food for growth and survival of rainbow trout larvae compared to commercial concentrated food were investigated in this study. The larvae with average weight of 92.9 mg were fed for 20 days with four food treatments included of commercial concentrated food, newly hatched Artemia, enriched Artemia, and mixture of enriched Artemia and concentrated food. At the end of experiment, the highest weight gain percentage was 104.4% in those larvae fed with enriched Artemia (p< 0.05). The highest survival rate was 96.5 % observed in larvae fed with mixture of enriched Artemia and commercial concentrated food (P<0.05). Larvae of third treatment that were fed with enriched Artemia with a survival rate of 98.9 %±1.9 under stress condition of low pH and survival rate of 66.5%±3.7 under stress condition of higher pH in rearing environment, were the most resistant larvae against stress resulting from pH fluctuation (P<0.05). Meanwhile the highest resistance against stress, resulting from temperature changes, was seen in larvae of the third and fourth treatment with survival rate of 77.8% at 24°C respectively

    Magnetism in twisted triangular bilayer graphene quantum dots

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    Using a tight-binding model along with the mean-field Hubbard method, we investigate the effect of twisting angle on the magnetic properties of twisted bilayer graphene (tBLG) quantum dots (QDs) with triangular shape and zigzag edges. We consider such QDs in two configurations: when their initial untwisted structure is a perfect AA- or AB-stacked BLG, referred to as AA- or AB-like dots. We find that AA-like dots exhibit an antiferromagnetic spin polarization for small twist angles, which transits to a ferromagnetic spin polarization beyond a critical twisting angle θc\theta_c. Our analysis shows that θc\theta_c decreases as the dot size increases, obeying a criterion, according to which once the maximum energy difference between electron and hole edge states (in the single-particle picture) is less than (U/γ0)t0(U / \gamma_0)\, t_0, the spin-polarized energy levels are aligned ferromagnetically [UU is the Hubbard parameter and γ0\gamma_0 (t0t_0) the graphene intralayer (interlayer) hopping]. Unlike AA-like dots, AB-like dots exhibit finite magnetization for any twist angle. Furthermore, in the ferromagnetic polarization state, the ground net spin for both dot configurations agrees with prediction from Lieb's theorem

    A random tunnel number one 3-manifold does not fiber over the circle

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    We address the question: how common is it for a 3-manifold to fiber over the circle? One motivation for considering this is to give insight into the fairly inscrutable Virtual Fibration Conjecture. For the special class of 3-manifolds with tunnel number one, we provide compelling theoretical and experimental evidence that fibering is a very rare property. Indeed, in various precise senses it happens with probability 0. Our main theorem is that this is true for a measured lamination model of random tunnel number one 3-manifolds. The first ingredient is an algorithm of K Brown which can decide if a given tunnel number one 3-manifold fibers over the circle. Following the lead of Agol, Hass and W Thurston, we implement Brown's algorithm very efficiently by working in the context of train tracks/interval exchanges. To analyze the resulting algorithm, we generalize work of Kerckhoff to understand the dynamics of splitting sequences of complete genus 2 interval exchanges. Combining all of this with a "magic splitting sequence" and work of Mirzakhani proves the main theorem. The 3-manifold situation contrasts markedly with random 2-generator 1-relator groups; in particular, we show that such groups "fiber" with probability strictly between 0 and 1.Comment: This is the version published by Geometry & Topology on 15 December 200

    Quantum curves for Hitchin fibrations and the Eynard-Orantin theory

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    We generalize the topological recursion of Eynard-Orantin (2007) to the family of spectral curves of Hitchin fibrations. A spectral curve in the topological recursion, which is defined to be a complex plane curve, is replaced with a generic curve in the cotangent bundle TCT^*C of an arbitrary smooth base curve CC. We then prove that these spectral curves are quantizable, using the new formalism. More precisely, we construct the canonical generators of the formal \hbar-deformation family of DD-modules over an arbitrary projective algebraic curve CC of genus greater than 11, from the geometry of a prescribed family of smooth Hitchin spectral curves associated with the SL(2,C)SL(2,\mathbb{C})-character variety of the fundamental group π1(C)\pi_1(C). We show that the semi-classical limit through the WKB approximation of these \hbar-deformed DD-modules recovers the initial family of Hitchin spectral curves.Comment: 34 page

    The relationship between religion and risky behaviors among Iranian university students

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    One factor that protects an individual from risky behavior is religiosity, which is referred to as a shield against risky behaviors. Belief in God and religion plays an important role in young people’s lives, and in comparison with their non-religious peers. They engage less frequently in risky behaviors, such as violence and sexual relations. The present study investigated the relationship between religiosity and engagement in risky behaviors among students from the Pishva branch of the Islamic Azad University, Tehran Province in Iran. This is a descriptive, analytic cross-sectional study. The sample was comprised of 448 students from different degree majors attending the University. Participants completed two questionnaires, including the Risk-Taking Scale and Duke University Religion Index. The data analyses used one-way ANOVAs and Pearson’s correlations. This study found that students who engaged more often in organized religious activities and had higher intrinsic religiosity were less likely to engage in risky behaviors such as sexual risk taking, careless driving, violence, smoking, along with alcohol and drug abuse. Participants with higher involvement in private religious activities reported lower tendencies for the above-mentioned risky behaviors, except sexual risk taking. The findings of this study indicate that the different dimensions of religiousness are related to students’ tendency to avoid risky behavior. Thus, it appears that religion may have a role to play in preventing risky taking behavior in Iran

    Triangulated Surfaces in Twistor Space: A Kinematical Set up for Open/Closed String Duality

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    We exploit the properties of the three-dimensional hyperbolic space to discuss a simplicial setting for open/closed string duality based on (random) Regge triangulations decorated with null twistorial fields. We explicitly show that the twistorial N-points function, describing Dirichlet correlations over the moduli space of open N-bordered genus g surfaces, is naturally mapped into the Witten-Kontsevich intersection theory over the moduli space of N-pointed closed Riemann surfaces of the same genus. We also discuss various aspects of the geometrical setting which connects this model to PSL(2,C) Chern-Simons theory.Comment: 35 pages, references added, slightly revised introductio

    Effect of Organic and Chemical Fertilizers on Oil Content and other Agronomic Traits of Safflower (Carthamus tinctorios)

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    The effect of organic fertilizers, chemical nitrogen and phosphorus on oil content and some of agronomic traits of safflower (Carthamus tinctorius), was studied in 2014. A factorial arrangement of treatments in a randomized complete block design with three replications was used. Animal manure treatments (M1= Control, M2= 20 ton.ha-1, M3= 40 ton.ha-1), and Chemical fertilizer treatments (F1= Control, F2= 50 kg.ha-1 of nitrogen + 25 kg.ha-1 of P2O5, F3= 100 kg.ha-1 of nitrogen + 50 kg.ha-1 of P2O5, F4= 150 kg.ha-1 of nitrogen + 75 kg.ha-1 of P2O5) were assigned in plots. In this study characteristics such as: stem diameter, number of sub branch, number of kernels per m-2, biological yield, phosphorus agronomic efficiency, grain weight of capitol, phosphorus physiological efficiency, oil content, nitrogen content of grain, number of unfertile capitol, phosphorus appear recovery and capitol diameter were assessed. Results indicated that the interaction effects of chemical fertilizer and animal manure on the characteristics such as: number of sub branch, biological yield, and nitrogen content of grain, phosphorus agronomic efficiency, phosphorus physiological efficiency and phosphorus appear recovery was significant. The maximum and minimum of phosphorus physiological efficiency (65.88 and 6.21 kg.kg-1) were obtained in  treatment of 50 kg.ha-1 of nitrogen + 25 kg.ha-1 of P2O5 + 40 ton.ha-1 of animal manure and 50 kg.ha-1 of nitrogen + 25 kg.ha-1 of P2O5 + 20 ton.ha-1 of animal manure, respectively

    Models for length back-calculation in Caspian Kutum, Rutilus kutum (Pisces: Cyprinidae) from the Caspian Sea

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    The Caspian Kutum, Rutilus Kutum (Kamensky 1901) specimens were sampled by purse seine in the northern Iranian coast of the Caspian Sea at four locations: Feridoonkenar Shahed, Mahmoudabad Khoram, Lariim Azadi fishing coop, and the Shiroud River in Ramsar city. “Back-calculation” is a retrospective method of estimating the characteristics of growth of fish in terms of length and rate of growth in the years preceding capture. Backcalculation of fish lengths at previous ages from scales or otoliths is a widely used approach to estimate both individual and population growth history. The back-calculated lengths of the Caspian kutum, Rutilus kutum (Kamensky 1901) were obtained using six different models, namely scale proportional hypothesis, body proportional hypothesis, Fraser Lee, nonlinear scale proportional hypothesis, nonlinear body proportional hypothesis, and the newest method, Morita Matsuishi model. The results showed that the preferred backcalculation models is Fraser Lee model for both males and females, while the nonlinear body proportional hypothesis is only for the females

    Validity and Reliability of the Persian Version of the Food Thought Suppression Inventory for Obese University Students

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    Objectives: To determine the validity and reliability of the Persian version of the Food Thought Suppression Inventory (FTSI) in overweight university students in Iran. Methods: A sample of 233 overweight students were recruited from five universities in Tehran. Participants were asked to complete the Persian versions of FTSI, Binge Eating Scale, Thought Control Questionnaire, Rumination Response Scale, and Dutch Eating Behaviour Questionnaire. Sociodemographic characteristics of participants were also collected. Results: Validity of the Persian version of the FTSI was verified by the fitting indices of the proposed single-factor model of the main makers (Χ2= 112.75, df = 90, p = 0.052, Χ2/df = 1.25, goodness-of-fit index = 0.93, comparative fit index = 0.96, non-normed fitness index = 0.96, root mean score of error approximation = 0.032, and standardised root mean residual = 0.052). Internal consistency of the instrument was high, with a Cronbach's alpha of 0.88. Conclusion: The Persian version of the FTSI is a valid and reliable tool for screening patients in obesity clinics and for evaluating treatment outcomes. © 2020 Hong Kong Academy of Medicine Press. All rights reserved
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