177 research outputs found

    Cytogenetic study on Artemia from Urmiyah Lake

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    To determine the chromosome numbers of artemia brine-shrimp in Urmiyah Lake (Azarbaijan-e- Gharhi province), cytogenetic studies were carried out on artemia cysts. In order to identify the collected samples, each sample of cysts, first incubated in sea water (35 ppt salinity) and then to determine the reproduction mode, the cyst samples were feed with Dunaliella tertiolecta, for three generations (F3) up to adult. The results showed that there were two types of anemia in terms of reproduction mode, namely bisexual and parthenogenesis. Chromosome spreads were prepared from freshly hatched nauplius squashing method. The results of counting 100 metaphases plates from bisexual artemia and 35 metaphases plates of parthenogenetic specimen, it was found that the number of chromosomes in these 2 types of artemia were the same, 2n=42. In these population, very small chromosomes with metacentric, submetacentric, telocentric and acrocentric types were observed. Karyotype formulas of bisexual and parthenogenetic artemia were determined as 2n=30 M / SM+12 A/T and 2n=32 M / SM+10 A/T, respectively. All studied samples in Interphase stage lacked and chromocenter. Due to very small size of chromosomes, it was difficult to do precise determination of the type of chromosomes and in this regard various C.banding experiments were performed. Also, since chromosomes in artemia lacked any chromocenter, the differentiation of chromosomes based on the types of C.banding was impossible

    Blood serum osmotic and ionic regulation of wild adults and reared juvenile Persian sturgeon, Acipenser persicus

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    The osmoregulatory system was studied in wild adult and reared juvenile Persian sturgeon, Acipenser persicus. The mean osmolarity in blood serum of specimens from the Caspian Sea, estuary, the Kouraneski pools and the rearing tanks were 305.3±14.3, 308.7±25.8, 265.0±19.1 and 259.3±8.8 mosmol/L, respectively; the mean concentrations of Na+ were 151.2±6.3, 152.2±8.4, 142.5±5.9 and 131.4±4.1 meq/L whereas mean concentrations of K+ were 2.7±0.9, 3.6±0.9, 3.1±0.5 and 2.6±0.5meq/L, respectively. The concentrations for Mg++ ion in fish of the same four origins were 1.5±0.2; 1.5±0.3, 0.8±0.2 and 0.7±0.2 meq/L, and those of Ca++ were 2.31±0.51, 2.61±0.51, 1.85±0.58 and 1.46±0.43, respectively. The Pearson's correlation coefficient and regression equation indicated that Mg++(r =0.38) and Na+ (r=0.41) were effective ions for determination of blood serum osmotic pressure in A. persicus in brackish water and freshwater. This study also showed that blood serum osmotic pressure was independent of sex

    Identification of metallothionein gene structure in sterlet (Acipenser ruthenus)

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    Aquatic organisms present, not only simple sources of accumulated metal, but can interact with metals, altering their toxicity. Due to exposition of biosphere with metals, organisms have developed various defense mechanisms to protect themselves against adverse effects of these ions and their compounds. Metallothionein (MT) is one of that which represents a critical mechanism for detoxification of metals. The sterlet (Acipenser ruthenus) is a bottom feeding sturgeon species and because the fish are dependent on invertebrate species for food throughout their life cycle, the sterlet could be a good indicator of the quality of the state of water ecosystem. Addition of copper to water leads to the induction of MT. The present study analyzed MTgene primary structure that was excreted from the liver of sterlet exposed to sub-lethal copper concentrations (0.075 mgL^-1 ). At the beginning to identify the molecular structure of Metallothionein of sterlet, a cDNA encoding MT was purified from livers of sterlet, and the MTgene was amplified. The primary structure of sterlet metallothionein (S-MT) contained 20 cysteine residues, which is the same as MTs of teleost fishes. Although, the primary structure of S-MT contained 63 amino acids, which is longer than any MT identified in teleost fishes but similar to the structure of MT gene in lake sturgeon and white sturgeon. The complete nucleotide sequence of the S-MTgene has been detected. We have determined the structure of the fish copper-binding protein by DNA sequence analysis of the gene

    Identification of bester hybrids (female Huso huso Linnaeus, 1758 and male sterlet Acipenser ruthenus Linnaeus, 1758) using AFLP molecular technique

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    In this study Amplified Fragment Length Polymorphism (AFLP) was applied to species identification of bester hybrids. Hybrids identification was performed by comparison of electrophoresis profiles with parental species. The simultaneous occurrence of diagnostic bands fixed in the parental species, genetic distance and identification and cluster analyses (UPGMA) allow a correct identification. We used 8 primer combinations (Eco+3, Mse+4) and a total of 250 bands (size range 40-1000 bp) were generated. Primer combinations of (E-AAT, M-CGAT) and (E-AAG, M-CGAT) produced diagnostic bands in hybrids and parental species. Moreover, the results of genetic identification showed that Bester hybrids are more similar to beluga (Huso huso) (0.68) in comparison with sterlet (Acipenser ruthenus) (0.45).The results suggested that this technique could be suitable for precise identification of species and inter-generic hybrids like bester

    Cognitive Analysis of Factors Influencing the Use of Information Technology Based on Change Management at the Ministry of Sport and Youth of the Islamic Republic of Iran

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    Background and Objective:Today, the use of information technology is an integral part of jobs, especially management. Sports managers must be able to persuade technical experts to use information technology innovations to change the nature of the organization's jobs and affairs in order to be more productive and effective. If there is an obstacle to the use of information technology, the organization will no longer be effective and competitive. IT teaches managers how to repair an organization and start a new business, and how to be effective in relation to the environment and other organizations. Therefore, in case of problems in the implementation of information technology and there are obstacles in the way of its application in the organization, the organization will become an unusable ruin and compete with other organizations. The purpose of this research was cognitive analysis of factors influencing the use of Information Technology based on change management at the Ministry of Sport and Youth of the Islamic Republic of Iran. Methods: The research method is descriptive-survey and the study is applied considering its purpose. The statistical population includes 812 employees of all sections of the Ministry of Sports and Youth in 2016. The statistical sample size was calculated on the basis of Cochran's formula. 261 people were randomly selected based on stratified sampling. To collect data, two standard and international questionnaires were used: TEM for IT and ADKAR for change management. Findings:Data were analyzed through descriptive and inferential statistics including Kolmogorov-Smirnov test, single sample t-test, Pearson correlation coefficient and multiple regression tests. The results showed that in the cognitive analysis, the barriers to the use of information technology from the perspective of change management are: perceived utility, willingness to use, attitude towards application, and finally, the perceived ease of use in the application of the priority of the first to fourth. The findings indicate the extent to which these components are applied and influenced by the use of technology in the Ministry of Sports and Youth. Conclusion: When the use of a new technology, especially information technology, is supported by sports managers according to existing values and professional needs, the human resources of that organization will not only have more confidence in using information technology, but also a higher degree of perception and demonstrate the benefits of the system; and they will probably make better use of this technology. Therefore, some suggestions are presented below. Senior managers and those involved in sports pay more attention to the individual aspects of people working in the organization, provide the necessary training before the implementation of information systems and provide them with the benefits and capabilities of new technologies as well as usefulness and ease of use of technology components; also they need to familiarize themselves with information; involve others in the decisions that are made to use such technologies in order to get things done in less time or to facilitate the work process.   ===================================================================================== COPYRIGHTS  ©2019 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.  ====================================================================================

    Long-term outcome of patients with transposition of the great arteries and a systemic right ventricle:A systematic review and meta-analysis

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    BACKGROUND: Patients with a transposition of the great arteries (TGA) and a systemic right ventricle are at risk of heart failure (HF) development, arrhythmia and early mortality. Prognostic evaluations in clinical studies are hampered by small sample sizes and single-centred approaches. We aimed to investigate yearly rate of outcome and factors affecting it.METHODS: A systematic literature search of four electronic databases (PubMed, EMBASE, Web of Science and Scopus) was conducted from inception to June 2022. Studies reporting the association of a systemic right ventricle with mortality with a minimal follow-up of 2 years during adulthood were selected. Incidence of HF hospitalization and/or arrhythmia were captured as additional endpoints. For each outcome, a summary effect estimate was calculated.RESULTS: From a total of 3891 identified records, 56 studies met the selection criteria. These studies described the follow-up (on average 7.27 years) of 5358 systemic right ventricle patients. The mortality incidence was 1.3 (1-1.7) per 100 patients/year. The incidence of HF hospitalization was 2.6 (1.9-3.7) per 100 patients/year. Predictors of poor outcome were a lower left ventricular (LV) and right ventricular ejection fraction (RVEF) (standardized mean differences (SMD) of -0.43 (-0.77 to -0.09) and - 0.85 (-1.35 to -0.35), respectively), higher plasma concentrations of NT-proBNP (SMD of 1.24 (0.49-1.99)), and NYHA class ≥2 (risk ratio of 2.17 (1.40-3.35)).CONCLUSIONS: TGA patients with a systemic right ventricle have increased incidence of mortality and HF hospitalization. A lower LVEF and RVEF, higher levels of NT-proBNP and NYHA class ≥2 are associated with poor outcome.</p

    Population genetic structure of Persian sturgeon (Acipenser persicus) between South Caspian Sea and Sefidrud River using DNA sequencing method

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    The goal of this study was to analyse the population genetic structure of the Persian sturgeon (Acipenser persicus) between South Caspian Sea and Sefidrud River with mtDNA control region (Dloop gene) and DNA sequencing method during 2010 – 2012 sturgeon stock assessment project. Fish speciemns were collected by bottom trawl net. Extraction of DNA, PCR and DNA sequencing were carried out. Diversity index, the gamma distribution shape parameter for the rate heterogeneity among sites and nucleotide sequence, Fst index, exact test, the historical demographic pattern using neutrality tests and mismatch distribution analysis (D test of Tajima and Fs test of Fu) were analysed. Thirteen haplotypes were obtained, average (±SD) for haplotype diversity was 0.961 ± 0.101, nucleotide diversity was 0.038 ± 0.015, the gamma distribution shape parameter was 0.19, Fst index revealed little genetic structure between populations and the significant Fst value was seen by 10000 permutation only between Sefidrud River and Other Areas (P≤ 0.05) and was confirmed by exact test of population differentiation. Mismatch distribution for Acipenser persicus appeared to be unimodal, which closely matched the expected distributions under the sudden expansion model and supported by the low Harpending’s Raggedness index (0.061). Tajima’s D and Fu’s Fs statistics were -0.84 and - 0.220, respectively, and was not significant. The results of this study showed that the population of Acipenser persicus in Sefidrud River were genetically differentiated from South Caspian Sea and three other areas represented a single panmictic populations. Therefore, fisheries managements of this valuable species should be directed towards conservation of gene pools and increasing different populations

    Long-term outcome of patients with transposition of the great arteries and a systemic right ventricle:A systematic review and meta-analysis

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    BACKGROUND: Patients with a transposition of the great arteries (TGA) and a systemic right ventricle are at risk of heart failure (HF) development, arrhythmia and early mortality. Prognostic evaluations in clinical studies are hampered by small sample sizes and single-centred approaches. We aimed to investigate yearly rate of outcome and factors affecting it.METHODS: A systematic literature search of four electronic databases (PubMed, EMBASE, Web of Science and Scopus) was conducted from inception to June 2022. Studies reporting the association of a systemic right ventricle with mortality with a minimal follow-up of 2 years during adulthood were selected. Incidence of HF hospitalization and/or arrhythmia were captured as additional endpoints. For each outcome, a summary effect estimate was calculated.RESULTS: From a total of 3891 identified records, 56 studies met the selection criteria. These studies described the follow-up (on average 7.27 years) of 5358 systemic right ventricle patients. The mortality incidence was 1.3 (1-1.7) per 100 patients/year. The incidence of HF hospitalization was 2.6 (1.9-3.7) per 100 patients/year. Predictors of poor outcome were a lower left ventricular (LV) and right ventricular ejection fraction (RVEF) (standardized mean differences (SMD) of -0.43 (-0.77 to -0.09) and - 0.85 (-1.35 to -0.35), respectively), higher plasma concentrations of NT-proBNP (SMD of 1.24 (0.49-1.99)), and NYHA class ≥2 (risk ratio of 2.17 (1.40-3.35)).CONCLUSIONS: TGA patients with a systemic right ventricle have increased incidence of mortality and HF hospitalization. A lower LVEF and RVEF, higher levels of NT-proBNP and NYHA class ≥2 are associated with poor outcome.</p
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