168 research outputs found

    Heavy metal concentrations in the selected tissues of the Persian sturgeon, Acipenser persicus, from the southern coast of the Caspian Sea

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    Bioaccumulation of heavy metals including Cd, Pb, Cu and Zn in muscle, gill, liver, kidney and stomach in Acipenser persicus was studied. Fish were collected from the ‘Iranian fishery zone 1’ located between Astara and Kiyahshahr. Samples (n=25) were collected from five stations in the study area during the autumn catch season in 2001. Samples were analyzed by wet digestion with hydrogen peroxide and nitric acid. Analyses were testified using spike method. A sample of bovine liver (CRM 185R) was tested to ascertain reliability of analyses. Digested samples were analyzed using Flame Atomic Absorption Spectrophotometer. The bioaccumulation pattern for Zn in different tissues studied was stomach>liver> kidney> gills>muscle tissue. The mean concentration of Zn in the stomach was 136.6±10.70μg g-1 dry weight. Cu with the maximum concentration of 39.71±8.85μg g-1 dry weight in liver showed a bioaccumulation pattern of liver>kidney>stomach>gills>muscle tissue. The bioaccumulation pattern for Pb was determined as gills>liver> kidney>stomach>muscle tissue. Maximum mean concentrations of Pb 6.87±2.25μg g-1 dry weight belonged to gills. Bioaccumulation pattern for Cd in the different organs studied in A. persicus was kidney>liver>gills>stomach> muscle tissue. Maximum mean concentration of 5.1±0.97μg g-1 dry weight belonged to kidneys and the minimum mean concentration of 0.05±0.007μg g-1 dry weight belonged to muscle tissue. Concentration of the metals in the muscles samples were below the most guidelines for human consumption. Concentrations for heavy metals were lower than the guidelines in some organs and were higher than that in the other organs studied. The observed concentrations do not pose health problems as these organs are not used for human consumption

    Detection of Acinetobacter baumannii by PCR-ELISA method

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    زمینه و هدف: اسینتوباکتر بومانی عامل عفونت های دستگاه تنفسی، دستگاه ادراری، خون و زخم ها به خصوص در بخش مراقبت های ویژه می باشد و توانایی کسب مقاومت دارا می باشد. به منظور تشخیص به موقع و پیگیری فرایند درمان این عفونت ها، لازم است که تکنیک ها به طور مستمر اصلاح شوند. با توجه به اینکه تاکنون مطالعه ای در زمینه شناسایی و جداسازی این باکتری در نمونه های بالینی در ایران با روش PCR-ELISA انجام نشده است، این مطالعه با هدف جداسازی اسینتوباکتر بومانی با روش PCR-ELISA انجام شده است. روش بررسی: در این تحقیق روش PCR-ELISA با استفاده از آغازگرهای اختصاصی و پروب بر روی سویه استاندارد مورد بررسی قرار گرفت. بعد از تکثیر و نشاندار کردن توالی ژن gltA، محصول نشاندار در کف میکرو پلیت کوت گردید و با استفاده از آنتی بادی ضد دیگوکسی ژنین کانژوگه با پراکسیداز شناسایی شد. یافته ها: بررسی توالی bp722 از بخش حفظ شده ژن gltA اسینتوباکتر بائومانی و نتایج حاصل از مطالعه بر روی این باکتری با استفاده از روش PCR-ELISA و به کارگیری آغازگرها و پروب نشان داد که این روش علاوه بر دقت و حساسیت، برای تشخیص سریع باکتری مناسب است. نتیجه گیری: نتایج حاصل، حاکی از حساسیت بیشتر و سرعت بالای روش PCR-ELISA در مقایسه با PCR معمولی است. این تکنیک همچنین علاوه بر سهولت بررسی تعداد بیشتر نمونه، از خطر کمتری نسبت به روش PCR معمولی برخوردار است

    Assessing heavy metal content of muscle tissue and caviar of Acipenser persicus and Acipenser stellatus in southern Caspian Sea

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    WE sampled 139 specimen of Acipenser persicus and 103 Acipenser stellatus over the years 19984999 in five fishing zones of the southern Caspian Sea for heavy metal contamination assessment. Flame Atomic Absorption Spectrophotometery was used to determine contamination of the specimens with Zn, Cu, Cd, and Pb and cold vapor method for Hg. The mean age for A. persicus and A. stellatus was 17.6±2.6 years and 11.9±1.8 years, respectively. The mean concentrations of heavy metals assessed for dry weight of the muscle tissues and caviar in A. persicus were 26.9 and 65.9 µg/g for Zn, 1.8 and 4.2 µg/g for Cu, 0.61 and 0.111 µg/g for Pb and 0.61 and 0.005 µg/g for Cd. The wet weight concentration of Hg in the muscle tissue and caviar of the fish were 0.06 and 0.007 µg/g respectively. For A. stellatus we determined the mean concentration of heavy metals in dry weight of the muscle tissue and caviar to be 27.4 and 57.8 µg/g for Zn, 1.64 and 4.85 µg/g for Cu, 0.481 and 0.112 µg/g for Pb and 0.59 and 0.005 µg/g for Cd while the wet weight concentration of Hg were 0.05 and 0.008 µg/g. By international standards, the contamination of the muscle tissue and caviar samples with the heavy metals in the two sturgeon species are well below maximum allowable for human consumption

    Late Little Ice Age palaeoenvironmental records from the Anzali and Amirkola Lagoons (south Caspian Sea): Vegetation and sea level changes

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    This is a postprint version of the article. The official published article can be found from the link below - Copyright @ 2011 Elsevier Ltd.Two internationally important Ramsar lagoons on the south coast of the Caspian Sea (CS) have been studied by palynology on short sediment cores for palaeoenvironmental and palaeoclimatic investigations. The sites lie within a small area of very high precipitation in a region that is otherwise dry. Vegetation surveys and geomorphological investigations have been used to provide a background to a multidisciplinary interpretation of the two sequences covering the last four centuries. In the small lagoon of Amirkola, the dense alder forested wetland has been briefly disturbed by fire, followed by the expansion of rice paddies from AD1720 to 1800. On the contrary, the terrestrial vegetation reflecting the diversity of the Hyrcanian vegetation around the lagoon of Anzali remained fairly complacent over time. The dinocyst and non-pollen palynomorph assemblages, revealing changes that have occurred in water salinity and water levels, indicate a high stand during the late Little Ice Age (LIA), from AD < 1620 to 1800–1830. In Amirkola, the lagoon spit remained intact over time, whereas in Anzali it broke into barrier islands during the late LIA, which merged into a spit during the subsequent sea level drop. A high population density and infrastructure prevented renewed breaking up of the spit when sea level reached its maximum (AD1995). Similar to other sites in the region around the southern CS, these two lagoonal investigations indicate that the LIA had a higher sea level as a result of more rainfall in the drainage basin of the CS.The coring and the sedimentological analyses were funded by the Iranian National Institute for Oceanography in the framework of a research project entitled “Investigation of the Holocene sediment along the Iranian coast of Caspian Sea: central Guilan”. The radiocarbon date of core HCGL02 was funded by V. Andrieu (Europôle Méditerranéen de l'Arbois, France) and that of core HCGA04 by Brunel University

    Genetic variation study on the grey mullet (Mugilcephalus) stocks from Mediterranean Sea, the Pacific Ocean and Oman Sea

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    Two of the three objectives of project was carried out success that one of them is following: The genetic diversity of Liza salien(Risso,1810) in the south part of Caspian sea using the Mitochondrial DNA sequencing (mtDNA) was carried out as first objective of project that based on the mitochondrial DNA sequencing (mtDNA) of 16S rRNA was used in order to clarify genetic structure and genetic diversity of lizasaliens in three western (Anzali), middle (sari), and eastern (Gomishan lagoon) of south part of Caspian sea. As a result we obtained 552base pairs of 16SrRNA sequence. A total of 6 different haplotypes and 29 variable sites were identified .The average nucleotide diversity(π) and haplotype diversity(h) in samples of all regions were 0.29 , and 0.004 respectively. The results obtained from genetic distance showed low rate in that of 3 regions. Estimates of gene flow indicated there is no reproductive isolation between three regions and also there was not significant genetic differentiation between differentregions (p>0.05). the findings from the present study suggest that there is equal population of Liza saliens in the studied regions: Genetic differences and phylogenic relationships among six Mugilidae species (Mugilcephalus, M. capito, Liza subviridis, L. saliens, L. aurata, Valamugilbuchanani) were determined using PCR-sequencing as second objective of project. M. cephalus, L. subviridis and V. buchanani from the Persian Gulf and Oman Sea, and L. aurata and L. saliens from the Caspian Sea were collected. Samples of an imported, Egyptian species M. capito (this species was mixed with the main imported species as M. cephalusfingerling) were obtained from the Gomishan Research Center in Gorgan. Total DNA from the samples were extracted according to phenol-chloroform method Mithochondrial DNA ,16s RNA was amplified using thermo cyclermachine with universal primers and thensequenced by sending to Takapoozist Company and thereafter to France. Analysis of the sequences showed great differences between Mugil species and the other studied species. The phylogenetic tree obtained through Neighbor-Joining method revealed that L. saliensand L. aurata were in the same branch while L. subviridis was in a separate branch. In contrast, Maximum Parsimony tree located L. subviridis and L. aurata in a single branch and assigned L. saliens to a distinct branch. This result brings in the question of monophyletic origin of the genus Liza.Also

    Effect of Cold Stress on Photosynthetic Traits, Carbohydrates, Morphology, and Anatomy in Nine Cultivars of Stevia rebaudiana

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    Stevia rebaudiana Bertoni is a sweet medicinal herb that is cultivated worldwide. This study aimed to identify the genotypic responses and function of nine cultivars of S. rebaudiana (accession numbers 1-9 from the EUSTAS Stevia Gene Bank) to low temperature. Plants were grown in vitro and incubated under controlled conditions at 5 degrees or 25 degrees C for 1 month. Cold stress significantly decreased the maximum quantum yield of photosystem II (F-v/F-m) in all cultivars, which was more pronounced in cultivars 5, 6, 8, and 9. The efficiency of photosystems I and II (PIABS) also declined in cold-stressed plants and was accompanied by reductions in net photosynthesis (P-N), intercellular CO2 (C-i), water use efficiency (WUE), and chlorophyll a, chlorophyll b and carotenoid contents, more so in cultivars 5, 6, 8, and 9. Regardless of the downregulation of photosynthetic capacity, the cold stress increased water-soluble carbohydrates in all cultivars, which was accompanied by an increase in fresh leaf mass and area, more so in cultivars 5, 6, 8, and 9. Furthermore, cold stress increased the stomatal index and density, epidermal cell density, stem diameter, xylem vessel width, phloem tissue width, and number of sclerenchyma in all cultivars. Even though the nine cultivars of S. rebaudiana had lower PSII efficiencies at low temperatures, the increase in carbohydrates and leaf mass suggests that damage to PSII is not responsible for the reduction in its efficiency

    Mapping 123 million neonatal, infant and child deaths between 2000 and 2017

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    Since 2000, many countries have achieved considerable success in improving child survival, but localized progress remains unclear. To inform efforts towards United Nations Sustainable Development Goal 3.2—to end preventable child deaths by 2030—we need consistently estimated data at the subnational level regarding child mortality rates and trends. Here we quantified, for the period 2000–2017, the subnational variation in mortality rates and number of deaths of neonates, infants and children under 5 years of age within 99 low- and middle-income countries using a geostatistical survival model. We estimated that 32% of children under 5 in these countries lived in districts that had attained rates of 25 or fewer child deaths per 1,000 live births by 2017, and that 58% of child deaths between 2000 and 2017 in these countries could have been averted in the absence of geographical inequality. This study enables the identification of high-mortality clusters, patterns of progress and geographical inequalities to inform appropriate investments and implementations that will help to improve the health of all populations

    Global, regional, and national burden of colorectal cancer and its risk factors, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019

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    Funding: F Carvalho and E Fernandes acknowledge support from Fundação para a Ciência e a Tecnologia, I.P. (FCT), in the scope of the project UIDP/04378/2020 and UIDB/04378/2020 of the Research Unit on Applied Molecular Biosciences UCIBIO and the project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy i4HB; FCT/MCTES through the project UIDB/50006/2020. J Conde acknowledges the European Research Council Starting Grant (ERC-StG-2019-848325). V M Costa acknowledges the grant SFRH/BHD/110001/2015, received by Portuguese national funds through Fundação para a Ciência e Tecnologia (FCT), IP, under the Norma Transitória DL57/2016/CP1334/CT0006.proofepub_ahead_of_prin
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