255 research outputs found

    Estimation of population dynamics parameters of Scomberomorus commerson using modal progression method in the Hormouzgan province waters

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    Scombermorus commerson is one of the most important commercial fish species in the Persian Gulf and Sea of Oman. To arrange for a sustainable fishing pattern, growth parameters, mortality and exploitation rates of the fish were estimated. Fish length data were collected from 4515 fishes, science April 2007 to March 2008 in three major artisanal fish-landing sites Bandar Lengeh, Bandar Abbas and Bandar Jask in Hormouzgan province waters. The Von Bertalanffy growth parameters (L∞ K and t _(0)) were estimated at 150.24 (cm), 0.66 year ^(-1) and -0.157 year, respectively. The results showed that S. commerson grows very fast in the first 2 years. The results indicated that S. commerson attains its fork length 80.3 cm at the end of first year. The fork length attained at the end of the second, third and fourth years were 114.1, 131.6 and 140.6 cm, respectively. Growth performance index (f) was calculated at 4.1 which were in agreement with the findings of the other studies in the Indian Ocean. Total, natural, fishing mortality and exploitation rate were estimated at 2.11, 0.67, 1.44 year ^(-1) and 0.64, respectively. Five cohorts were distinguished based on Bhattacharya's method

    Fishing pattern, maximum constant yield (MCY) and recruitment pattern of Thunnus tonggol in Hormuzgan province

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    Thunnus tonggol is one of the most important large pelagic fish species in Hormuzgan province waters. Nominal catch of T. tonggol in 2010 was 32405 tones comprising 65% of total catch of large pelagic fishes. For sustainable exploitation of the resources of this fish, we need to identify its fishing pattern, maximum constant yield and recruitment pattern. Hence, length and weight data were collected randomly from 6 major artisanal fish-landing sites Hassineh, Kong, Bandar Abbas, Salakh, Sirik and Jask in Hormuzgan province, starting in April 2010 over one year. Growth parameters L∞ and K were estimated at 112.23cm 0.3 and (1/year), respectively. Hence, the natural mortality was calculated at 0.43 (1/year) and the maximum constant yield was computed at 11880 tones. Length-weight power relationship, W= aFLb , was W= 3×10-05FL2.82 that showed T. tonggol have isometric growth. Fishing pattern indicated that almost 85% of the catch was under the size at first maturity. Maximum recruitment pattern was in November with average fork length being 27cm. For optimum exploitation of T. tonggol stocks, we suggest two approaches including fishing ban in the maximum recruitment time and gear (Drift gillnet) modification

    Evaluation inhibitory effect of essential oil Savory (Satureja hortensis) in food fish

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    Aflatoxins are a group of fungal metabolites that are produced by the growth of fungi on food. These toxins cause illness in animals and humans, and are important in economic and humans health. In this investigation, inhibitory effects of savory (Satureja hortensis L.) essential oil were evaluated on the growth of Aspergillus flavus in fish food. A gas chromatograph apparatus linked to a mass spectrometer (GC/MS) was used to identify the effective components in Satureja hortensis essential oil after extraction. Essential oils against Aspergillus flavus incubated in PDA media and antifungal properties of essential oil Satureja hortensis was investigated. About of 300g of food samples was weighted and samples were sterilized by autoclave. Fungal suspension (3cc) was spraied into the feed samples, and various concentrations of essential oils (0, 300, 400, 500, 600ppm) added to samples. The samples were incubated at temperature of (±SD) 28±2°C. After 20-40 and 60 days period, randomly, some sampled were taken from containers and the production of aflatoxin B1, B2, G1, and G2 was measured in the laboratory. This result confirms that 500ppm concentrations of oil savory have antifungal properties against Aspergillus flavus

    Polymer architecture effect on rheology and segmental dynamics in poly (methyl methacrylate)-silica nanocomposite melts

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    Architecturally different polymer chains lead to fundamentally different rheological responses and internal dynamics, which can be utilized to rationalize advanced thermoplastic nanocomposites with tunable mechanical behavior. In this work, three model poly (methyl methacrylate) (PMMA) polymers with linear, bottlebrush, and star architectures with the same total molar mass were investigated in their neat form, and nanocomposites with well-dispersed silica nanoparticles using rheology and broadband dielectric spectroscopy (BDS). The master curves of the dynamic moduli obtained by time-temperature superposition (TTS) over the entire range from the Rouse regime to the terminal flow and a sequence of significantly different relaxation modes were observed for the samples with linear and branch chains. While linear chains form an entangled polymer network, the branched bottlebrush, and star chains show a viscoelastic response with no sign of rubbery entanglement plateau and a weak arm relaxation regime between Rouse and terminal flow, akin to other branched polymers. Moreover, branched chains showed a higher fragility index (m = 3.46 for the bottlebrush and 5.36 for the star) compared to linear chains (m = 3.29) due to dynamical heterogeneities induced by arm relaxation. The addition of nanoparticles affects only the terminal relaxation regime, where the whole chain motion is hindered by the attractive nanoparticles. The dynamics of the polymer segment were investigated by performing broadband dielectric spectroscopy (BDS) at a frequency range from 10-2 Hz to 107 Hz. The results revealed more than 10 times slower segmental relaxation for the star homopolymers and a slowdown in the α-relaxation process for all three architectures in their composite form. The dynamical slowdown in the composites is temperature dependent and more pronounced at low temperatures (leading to approximately equal to 80 times slower dynamics for nanocomposite with bottlebrush PMMA at 150 °C) due to prolonged relaxation of the interfacial polymer compared to the matrix chains. The results from this study have practical applications in fields such as gas separation and polymeric electrolyte membranes, where simultaneous improvement of segmental mobility and mechanical moduli is highly desired

    The Serum Lead level in Patients With Retained Lead Pellets

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    Background: Patients, who survived from shotgun injuries, often have some retained lead pellets in their bodies. Several cases of lead toxicity have been reported regarding these patients. Objectives: This study seeks to compare the serum lead level in patients who have retained lead pellets in their bodies with the control group. Patients and Methods: In this case-control study, we gathered the serum lead levels of 25 patients with some retained lead pellets in their bodies due to shotgun and 25 volunteers without similar lead exposure and compared them in view of the age, gender, and living place. Results: While the mean serum lead level in both groups was lower than the standard level (i.e. 40 µg/dL) , the mean ± SD of serum lead level were 29 ± 12.8 µg/dL and 25.3 ± 6.4 µg/dL in the case and control groups, respectively without any significant difference (P = 0. 30) . However, a positive relationship was seen between serum lead level, and the number of retained lead pellets (r = 0.447, P = 0. 025) . Conclusions: Although extensive surgery to remove the lead pellets is not recommended in patients injured with shotguns, those with many retained lead pellets in their bodies should be considered at risk for lead poisoning and monitored carefully

    Copy number variation genotyping using family information

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    BACKGROUND: In recent years there has been a growing interest in the role of copy number variations (CNV) in genetic diseases. Though there has been rapid development of technologies and statistical methods devoted to detection in CNVs from array data, the inherent challenges in data quality associated with most hybridization techniques remains a challenging problem in CNV association studies. RESULTS: To help address these data quality issues in the context of family-based association studies, we introduce a statistical framework for the intensity-based array data that takes into account the family information for copy-number assignment. The method is an adaptation of traditional methods for modeling SNP genotype data that assume Gaussian mixture model, whereby CNV calling is performed for all family members simultaneously and leveraging within family-data to reduce CNV calls that are incompatible with Mendelian inheritance while still allowing de-novo CNVs. Applying this method to simulation studies and a genome-wide association study in asthma, we find that our approach significantly improves CNV calls accuracy, and reduces the Mendelian inconsistency rates and false positive genotype calls. The results were validated using qPCR experiments. CONCLUSIONS: In conclusion, we have demonstrated that the use of family information can improve the quality of CNV calling and hopefully give more powerful association test of CNVs

    Copy number variation genotyping using family information

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    Abstract Background In recent years there has been a growing interest in the role of copy number variations (CNV) in genetic diseases. Though there has been rapid development of technologies and statistical methods devoted to detection in CNVs from array data, the inherent challenges in data quality associated with most hybridization techniques remains a challenging problem in CNV association studies. Results To help address these data quality issues in the context of family-based association studies, we introduce a statistical framework for the intensity-based array data that takes into account the family information for copy-number assignment. The method is an adaptation of traditional methods for modeling SNP genotype data that assume Gaussian mixture model, whereby CNV calling is performed for all family members simultaneously and leveraging within family-data to reduce CNV calls that are incompatible with Mendelian inheritance while still allowing de-novo CNVs. Applying this method to simulation studies and a genome-wide association study in asthma, we find that our approach significantly improves CNV calls accuracy, and reduces the Mendelian inconsistency rates and false positive genotype calls. The results were validated using qPCR experiments. Conclusions In conclusion, we have demonstrated that the use of family information can improve the quality of CNV calling and hopefully give more powerful association test of CNVs.http://deepblue.lib.umich.edu/bitstream/2027.42/112374/1/12859_2012_Article_5896.pd

    Environmental engineering applications of electronic nose systems based on MOX gas sensors

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    Nowadays, the electronic nose (e-nose) has gained a huge amount of attention due to its ability to detect and differentiate mixtures of various gases and odors using a limited number of sensors. Its applications in the environmental fields include analysis of the parameters for environmental control, process control, and confirming the efficiency of the odor-control systems. The e-nose has been developed by mimicking the olfactory system of mammals. This paper investigates e-noses and their sensors for the detection of environmental contaminants. Among different types of gas chemical sensors, metal oxide semiconductor sensors (MOXs) can be used for the detection of volatile compounds in air at ppm and sub-ppm levels. In this regard, the advantages and disadvantages of MOX sensors and the solutions to solve the problems arising upon these sensors’ applications are addressed, and the research works in the field of environmental contamination monitoring are overviewed. These studies have revealed the suitability of e-noses for most of the reported applications, especially when the tools were specifically developed for that application, e.g., in the facilities of water and wastewater management systems. As a general rule, the literature review discusses the aspects related to various applications as well as the development of effective solutions. However, the main limitation in the expansion of the use of e-noses as an environmental monitoring tool is their complexity and lack of specific standards, which can be corrected through appropriate data processing methods applications

    Epidemiology, incidence, and mortality of leukemia in children early infancy to 14 years old of age in south-central Asia: A global ecological study

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    Background: The cancer was considered the second cause of death from early infancy to 14 years of age after the inadvertent damage. Also, leukemia was reported as the most common type of cancer in infants. Objectives: The current study was aimed to evaluate the epidemiology, incidence, and mortality rates of leukemia from early infancy to 14 years of age in South-Central Asia. Methods: This is a descriptive cross-sectional study. In the current study, the incidence and mortality rates of leukemia in South-Central Asia were determined. The data were extracted from a Cancer Global Project in 2012 available at http://globocan.iarc.fr/Default.aspx.Results: In South-Central Asia, 1514027 cases of cancer were recorded in 2012 in which 480267 cases (3.2) were related to leukemia. The highest incidence rates of leukemia were reported for Iran, Kazakhstan, Sri Lanka, and Uzbekistan with the ratio of 3.6, 3.2, and 3 cases per 100000 people, respectively compared with the lowest incidence rates in Bangladesh, and Bhutan with the ratio of 0.8 and 0.9 cases per 100000 people, respectively in under14-year-old infants. Conclusions: Leukemia was reported as the most common type of cancer in infants, providing important information about possible changes of risk factors considering that its trend might help us to find critical ways so as to decrease the rate of cancer in infants. Copyright © 2019, Journal of Comprehensive Pediatrics

    Monitoring of commercial marine stocks around Hormuzgan (bandar-e-Lengeh) artificial reefs

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    Over-fishing of marine resources has endangered many commercial fish species in the world; with aquaculture development, setting up artificial reef systems is an important way for marine stocks and fishing enhancement. The present study was designed to monitor fish abundance and species changes around a small and newly established artificial reef system in Moloo area at Bandar-e-Lengeh during two years after installation (Sep. 2005 to Sep. 2007). The artificial reef includes three types of concrete structures arranged in a seven by three grid. Each cross point considered as a sampling station and two other stations selected from two sides of the system as control stations. Based on obtained results CPUE (P = 0.00001), frequency (P = 0.001) and species diversity of captured fishes (P = 0.024) showed significant differences between three types of sampling traps. With type of structures, The CPUE and frequency of fishes in transect 7(mixed structures) showed the significant differences with other six transects (p= 0.001, P = 0.009). No diversity relationships were seen between transects (p= 0.100). In this study there were no significant differences between depths. Although the means of CPUE between seasons were different, but the ANOVA test could not show the significant differences because of the differention between variances. The T-Test showed no significant differences between the numbers per trap per day dominant species (Epinephelus coioides, Plectorhinchus shotaf, Diagrama pictum, Siganus javus) in different seasons. Movie prepared from artificial reefs showed diversity of fish were more than that of fishing by trap. Although fishes increased but there was no enough causes evidences for product in artificial reefs. Therefore, the study need to continue in this area
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