526 research outputs found

    The effect of dietary nucleotide on the haematological and serum biochemical parameters of Persian sturgeon (Acipenser persicus) juveniles

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    This study was aimed to examine the impact of different levels of dietary nucleotides (Vannagen) on serum biochemical and blood parameters of Persian sturgeon (Acipenser persicus). Fish (42.37± 2.12 g and 23.67± 0.61 cm) were divided into four treatments with different levels of dietary nucleotides (0, 0.25, 0.35 and 0.5 percent of diet). There were three replicates with a density of 12 fish per tank. After 10 weeks of feeding, serum biochemical and blood parameters were measured. Among the measured factors, blood glucose, triglycerides, cholesterol, erythrocyte and heterophil showed significant differences between the groups fed with nucleotides and the control group (P ≤ 0.05). By increasing the nucleotide levels, the mean heterophil and serum glucose showed significant increase and decrease, respectively. The highest and lowest values of cholesterol and triglyceride were found in groups fed with 0.25% and 0.35% nucleotides, respectively. The other measured factors had no significant difference (P≤0.05). Therefore, it could be said that with regard to the limited capacity of cells to synthesize nucleotides, external preparing of nucleotides could result in the production of needed nucleotides and an increase of its production speed, especially during stress. Such preparation can also improve fish physiology and health status

    Evaluating responses to temperature during pre-metamorphosis and carry-over effects at post-metamorphosis in the wood tiger moth (Arctia plantaginis)

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    Insect metamorphosis is one of the most recognized processes delimiting transitions between phenotypes. It has been traditionally postulated as an adaptive process decoupling traits between life stages, allowing evolutionary independence of pre- and post-metamorphic phenotypes. However, the degree of autonomy between these life stages varies depending on the species and has not been studied in detail over multiple traits simultaneously. Here, we reared full-sib larvae of the warningly coloured wood tiger moth (Arctia plantaginis) in different temperatures and examined their responses for phenotypic (melanization change, number of moults), gene expression (RNA-seq and qPCR of candidate genes for melanization and flight performance) and life-histories traits (pupal weight, and larval and pupal ages). In the emerging adults, we examined their phenotypes (melanization and size) and compared them at three condition proxies: heat absorption (ability to engage flight), flight metabolism (ability to sustain flight) and overall flight performance. We found that some larval responses, as evidenced by gene expression and change in melanization, did not have an effect on the adult (i.e. size and wing melanization), whereas other adult traits such as heat absorption, body melanization and flight performance were found to be impacted by rearing temperature. Adults reared at high temperature showed higher resting metabolic rate, lower body melanization, faster heating rate, lower body temperature at take-off and inferior flight performance than cold-reared adults. Thus our results did not unambiguously support the environment-matching hypothesis. Our results illustrate the importance of assessing multiple traits across life stages as these may only be partly decoupled by metamorphosis. This article is part of the theme issue 'The evolution of complete metamorphosis'.Peer reviewe

    The nature of the relationship between teacher and learner in comprehensive e-learning process with an emphasis on ideas of Deleuze

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    Background and Objectives: The aim of this research is study the nature of the relationship between teacher and learner in comprehensive e-learning process with an emphasis on ideas of Deleuze. With the expansion of e-learning, one of the important aspects of change in education is in the field of teaching and learning, including the relation between the teacher and the learner. In the analysis and evaluation of the nature of the relation and its role in human cognition, one of the post structuralist emerging paradigms is Deleuze's rhizomatic epistemology. In the area of Deleuze's ideas and electronic learning based on connectivism theory, separate researches have been done. However, what distinguishes this study from other studies is the assessment of the important fact that whether the new area which Deleuze names rhizomatic and by which means challenges the traditional relationships between the teacher and the learner in the tree system and deterritorializes can support the new atmosphere of electronic learning. Do these two accompany each other? MethodS:The methodology of this study is philosophical analysis and deduction, which were used to answer the research question (What is the nature of the relation between the teacher and the learner in the process of e-learning?). The method of data collection is desk-documentation study. Based on concept analysis, valid understanding of the concept and a clear explanation of its relationship with other concepts was achieved. Moreover, based on deductive approach, the implications of the nature of the relation between the teacher and the learner according to Deleuze's ideas in the process of teaching - learning in e-learning was assessed. Then, these were analyzed philosophically. In other words, Deleuze's rhizomatic epistemological concepts and the related elements on the one hand and the concepts of electronic learning based on connectivism theory on the other hand were analyzed, interpreted and clarified. In the end, the proportion of relation in e-learning to Deleuze's rhizomatic relation was evaluated.  Findings: First, basic factors in rhizomatic epistemology of Deleuze were investigated. Based on the findings of this study, the essentialistic of the relationship between the teacher and the learner, according to Deleuze’s opinions, is rhizomatic. This means that it has features such as Interconnection and heterogeneity, pluralism, immigration, mapping, and non-indicative dissociation of rhizome, suggesting nonlinear, horizontal and non-hierarchical, fluid and fragile, decentralizing, spontaneous and molecular, dense and multiplexed, flexible and permeable relationships. Second, the nature of relationship in virtual learning process was illuminated according to the principles of communication theory, which is the new theory of learning in the age of information and communication technology, communication in E-learning is a systemic and network communication that has nonlinear relationships among system components and network.According to this theory, E-learning is the process of network components communicating with each other. At the end, the nature of relationship virtual Learning in relation with, the nature of rhizomatic epistemology of Deleuze was examined Therefore, the orientation of communication in E-learning is in line with Deleuze's rhizomatic relationship. Conclusion: Based on connectivism theory, electronic education is the very process of network elements connecting with each other. Thus, the direction of e-learning is aligned with Deleuze's rhizomatic relation. Thus, Deleuze's rhizomatic relationships with regard to the capabilities it holds, promises the ideal relationship between the teacher and the learner in the E-learning era and can serve as a model to address some of the challenges of the traditional educational system.   ===================================================================================== COPYRIGHTS  ©2020 The author(s). This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, as long as the original authors and source are cited. No permission is required from the authors or the publishers.  ====================================================================================

    Genetic Variants of Cytochrome b-245, Alpha Polypeptide Gene and Premature Acute Myocardial Infarction Risk in An Iranian Population

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    Background: Oxidative stress induced by superoxide anion plays critical roles in the pathogenesis of coronary artery disease (CAD) and hence acute myocardial infarction (AMI). The major source of superoxide production in vascular smooth muscle and endothelial cells is the NADPH oxidase complex. An essential component of this complex is p22phox, that is encoded by the cytochrome b-245, alpha polypeptide (CYBA) gene. The aim of this study was to investigate the association of CYBA variants (rs1049255 and rs4673) and premature acute myocardial infarction risk in an Iranian population. Methods: The study population consisted of 158 patients under the age of 50 years, with a diagnosis of premature AMI, and 168 age-matched controls with normal coronary angiograms. Genotyping of the polymorphisms was performed by the polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). Results: There was no association between the genotypes and allele frequencies of rs4673 polymorphism and premature acute myocardial infarction (P>0.05). A significant statistical association was observed between the genotypes distribution of rs1049255 polymorphism and AMI risk (P=0.037). Furthermore, the distribution of AA+AG/GG genotypes was found to be statistically significant between the two groups (P=0.011). Conclusions: Our findings indicated that rs1049255 but not rs4673 polymorphism is associated with premature AMI

    Effect of different dietary protein levels on reproductive performance of paradise fish Macropodus opercularis

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    In this study, the effect of different protein levels, on paradise fish growth and reproduction were investigated. Thus, number of one thousand paradise fish (0.5 ± 0.01 g) were collected from hatchery bred brooders and divided into six group, each group was offered one of six experimental diet comprising different protein levels (25%, 30%, 35%, 40%, 45% and 50%). After six month feeding period, the highest weight gain (5.96± 0.17), the highest weight gain percentage (90.8 ± 0.31) were submitted in the group fed 40% protein. Moreover, the highest feed conversion ratio (0.9 ± 0.3) as well as daily growth was observed in this group. In the reproduction, the highest eggs released by the group fed with diet containing 45% protein. The GSI and the egg diameter and larval length were highest in 45% protein group. The group of 25% and 30% the reproduction efficiency was the lowest. Protein increment up to 50% had no effect on reproduction performance. No differences were seen in biochemical composition and amino acid profile of the ovaries between groups

    The effect of L-arginine supplementation on obesity-related indices: A systematic review and meta-analysis of randomized clinical trials

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    The clinical studies regarding the effect of L-arginine in human anthropometry have not been fully consistent, therefore, we carried out a systematic review and meta-analysis of randomized clinical trials in order to precisely evaluate and quantify the efficacy of L-arginine on weight, waist circumference, and BMI. We searched online databases including PubMed, SCOPUS, and Google Scholar for relevant articles up to September 2017. Eligible articles were reviewed by two independent investigators. Mean differences of the outcomes were used for calculation of weighted mean difference (WMD) derived from the random-effects model. Statistical heterogeneity between studies was examined using Cochran's Q-test and I2index. Funnel plot and Egger's tests were performed to assess the publication bias. In our initial search, we found 1598 publications, of which 8 RCTs (9 treatment arms) were included. The results of the meta-analysis displayed a significant reduction in WC following L-arginine supplementation (WMD: -2.97 cm; 95 CI: -4.75 to -1.18, P = 0.001). However, L-arginine intervention had not elicited a significant effect on BMI (WMD: -0.51 kg/m2; 95 CI: -1.11 to .08, P = 0.09) and body weight (WMD: -0.57 kg; 95 CI: -1.77 to 0.61, P = 0.34). Subgroup analyses displayed that longer-term interventions (�8 weeks) had a positive effect on body weight and using < 8 g/day L-arginine with longer duration (�8 weeks) could significantly decrease BMI. In conclusion, this meta-analysis result suggested L-arginine supplementation could reduce waist circumference without any significant effect on body weight and body mass index. © 2021 Hogrefe Verlag GmbH & Co. KG. All rights reserved

    The effect of endurance training intensity on the expression of perlipin-A protein of visceral adipose tissue, serum glucose and insulin levels in STZ-induced diabetic rats

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    Background and aims: Changes in the expression of lipid droplet adipocyte proteins, such as prelipipin A (PLINA) cause alter lipolysis and insulin resistance. The aim of this study was to compare the three endurance training intensities (low, moderate and high) on the expression of PLINA protein in visceral adipose tissue, serum glucose and insulin levels in male diabetic Wistar rats. Methods: 40 male Wistar rats were assigned to five groups (n=8) including diabetic group with low intensity endurance training, moderate intensity group, high intensity group, diabetic and healthy control groups. After induction of diabetic rats by injection of streptozotocin, endurance training was performed with different intensities for eight weeks, three sessions per week. The relative expression of PLINA protein was measured by western blot technique. One-way variance analysis and Tukey's post hoc test were used to determine the difference between the groups. Results: The results showed that there was a significant difference between PLINA levels in healthy and diabetic control groups with endurance training groups (with low, moderate and high intensity) (P=0.018). These differences were between low intensity training and healthy control groups (P=0.033) and between diabetic and healthy control groups (P=0.020). Serum glucose and insulin levels were significantly different between the diabetic control and endurance training groups (low, moderate and high) (P=0.001). This difference was between high-intensity training group with low intensity training (P=0.046), diabetic control (P=0.001) and healthy control (P=0.011) groups. Conclusion: Moderate and high intensity endurance training can compensate for the loss caused by diabetes in the expression of the PLINA protein and reduces serum levels of insulin and glucose in these mice. It seems that more intensity endurance training leads to more increase in PLINA expression in diabetic rats
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