106 research outputs found
Effects of using Artemia urmiana enriched with N-3 HUFA in first feeding of rainbow trout (Oncorhynchus mykiss) larvae
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
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 . Our analysis shows that
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 , the
spin-polarized energy levels are aligned ferromagnetically [ is the Hubbard
parameter and () 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
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
The relationship between religion and risky behaviors among Iranian university students
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
Quantum curves for Hitchin fibrations and the Eynard-Orantin theory
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 of an arbitrary
smooth base curve . We then prove that these spectral curves are
quantizable, using the new formalism. More precisely, we construct the
canonical generators of the formal -deformation family of -modules
over an arbitrary projective algebraic curve of genus greater than ,
from the geometry of a prescribed family of smooth Hitchin spectral curves
associated with the -character variety of the fundamental
group . We show that the semi-classical limit through the WKB
approximation of these -deformed -modules recovers the initial family
of Hitchin spectral curves.Comment: 34 page
Triangulated Surfaces in Twistor Space: A Kinematical Set up for Open/Closed String Duality
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)
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
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
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
- …