223 research outputs found

    Bayesian Inference For Exponential Distribution Based On Upper Record Range

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    This paper deals with Bayesian estimations of scale parameter of the exponential distribution based on upper record range (Rn). This has been done in two steps; point and interval. In the first step the quadratic, squared error and absolute error, loss functions have been considered to obtain Bayesian-point estimations. Also in the next step the shortest Bayes interval (Hight Posterior Density interval) and Bayes interval with equal tails based on upper record range have been found. Therefore, the Homotopy Perturbation Method(HPM) has been applied to obtain the limits of Hight Posterior Density intervals. Moreover, efforts have been made to meet the admissibility conditions for linear estimators based on upper record range of the form mRn+d by obtained Bayesian point estimations. So regarding the consideration of loss functions, the prior distribution between the conjunction family has been chosen to be able to produce the linear estimations from upper record range statistics. Finally, some numerical examples and simulations have been presented

    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

    Correlation of A G to A nucleotide substitution in upstream region of leptin with breast cancer susceptibility

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    Single nucleotide polymorphisms in leptin gene may increase the risk of breast cancer. The aim of this study was to investigate the association of leptin G-2548A gene polymorphism with breast cancer risk in an Iranian population. In a case-control study, 98 subjects including 45 women with breast cancer and 53 healthy women were recruited. The genotypes of G-2548A polymorphism were detected by polymerase chain reaction-restriction fragment length polymorphism. Our data revealed that there is a significant association between AG homozygote genotype and breast cancer risk (OR= 2.41, 95CI= 1.05-5.52, p= 0.037). Also, we observed that G allele marginally increases the breast cancer risk (OR= 1.92, 95CI= 1.00-3.70, p= 0.049). Based on our preliminary study, leptin G-2548A gene polymorphism may be a genetic risk factor for breast cancer and further studies with larger sample size are required to obtain more accurate results. © 2019, Indian Journal of Forensic Medicine and Toxicology. All rights reserved

    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 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

    Time Series Imputation via L1 Norm-Based Singular Spectrum Analysis

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    Missing values in time series data is a well-known and important problem which many researchers have studied extensively in various fields. In this paper, a new nonparametric approach for missing value imputation in time series is proposed. The main novelty of this research is applying the L1 norm-based version of Singular Spectrum Analysis (SSA), namely L1-SSA which is robust against outliers. The performance of the new imputation method has been compared with many other established methods. The comparison is done by applying them to various real and simulated time series. The obtained results confirm that the SSA-based methods, especially L1-SSA can provide better imputation in comparison to other methods

    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

    Effects of starvation and re-feeding on some hematological and plasma biochemical parameters of juvenile Persian sturgeon, Acipenser persicus Borodin, 1897

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    The effect of starvation and re-feeding was investigated on growth, hematology and biochemical parameters in juvenile Persian sturgeon (Acipenser persicus). Three hundred and seventy five fish (108±0.63 g) were divided into five feeding groups. The control group (C) was fed to satiation three times a day during the experiment. The four groups were starved for 1 (W1), 2 (W2), 3 (W3), and 4 (W4) weeks respectively, and then fed to satiation during a 4 week re-feeding period. The results indicated that some parameters including final weight, specific growth rate ,body weight increase, plasma enzymes (ALT, Alanine aminotransferase, AST, Aspartat aminotransferase and ALP, Alkaline phosphatise, hematological parameters [Mean corpuscular volume (MCV), mean corpuscular hemoglobin concentration (MCHC), and mean corpuscular hemoglobin (MCH)]were significantly affected by feeding regimes. The plasma cortisol, hematocrit, lymphocytes, neutrophils, eosinophils, and monocytes were not affected by starvation and subsequent re-feeding. These findings showed that short term starvations had no significant negative effects on growth performance, most biochemical and hematological parameters in Persian sturgeon could recover when re-feeding resumed

    Application of microsatellite markers to determine populations of the Persian sturgeon (Acipenser persicus) in the south of Caspian Sea

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    The objective of this study was to analyse the population genetic structure of the Persian sturgeon (Acipenser persicus) in Sefidrud and Gorganrud rivers watershed based on the characterization of microsatellite markers during 2006 - 2008. 100 samples of Persian sturgeon were collected from two regions. Four microsatellite loci (Ls68, Spl168, Spl173 and Afu68) were analyzed for the molecular characterization of this species which resulted in polymorphic patterns. DNA bands were analysed using Biocapt and GenAlex software package. A total of 109 alleles were observed of which the maximum number of alleles (17) were found in Spl168 locus which belonged to sturgeons from Sefidrud river's watershed and the minimum number of alleles (10) in Ls68 locus belonging to the sturgeons from Gorganrud river's watershed. Results of microsatellite analysis revealed that the differences between samples of two regions were not statistically significant (p>0.05), neither for the average number of alleles per locus nor for observed heterozygosities. The calculated Fst and Rst between two regions was 0.07 and 0.17 showing that the genetic difference was significant (p< 0.01). Samples from Sefidrud river's watershed in Spl173, Afu68 and Spl168 loci and samples of other regions in Afu68 and Spl168 loci were at Hardy-Weinberg equation. The genetic distance was calculated as 0.4 which represents a significant genetic difference between samples of two studied areas. In conclusion, this study suggests that the Persian sturgeons in two regions of the southern part of the Caspian Sea are genetically differentiated, therefore fisheries management of these unique stocks for restocking and conservation of gene pools is highly recommended

    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
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