23 research outputs found

    Breeding and reproduction of grey mullet (Mugil cephalus L.)

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    Mazandaran and Gorgan provinces have temperate climate, thus they have more potential for aquatic animal culture. There are thousands hectare of salt and useless lands in adjacent to Caspian Sea. As these areas have provided a favorable back ground for aquatic animal culture. As a result, the successful results obtained from imported gray mullet (Mugil cephalus) culture project in north climate, it has demonstrated that the gray mullet has a good biocharacteristic for culturing in pond enclosure environment and in different aquatic conditions (fresh water, brackish water and salt water). From 1998 until 2001, the broodstock yield and gray mullet artificial propagation projects were performed by fisheries research center of Mazandaran in Ghomishan prawn culture station in adjacent to Caspian Sea (East north of Mazandaran Province). This investigation executed during two stages (phases). At first stage, the goal of this project included the survey of possibility available about matured fish as well as induction of final maturation and artificial propagation for producing of broodstock and larva. In addition, in this way, we will obtain new information about gray mullet propagation and culture as marine species. We introduce mass production in aquaculture. At present research, the possibility of broodstock yield and artificial propagation of gray mullet have investigated by gray mullet fingerlings imported from Hong kong and then they have cultured in earth ponds of Ghomishan areas during five years (1994-1998). In order to broodstock production in spring 1998, two earth ponds (0.5 hectare) were prepared. 100 specimens of fish stock (1-2.5 kg weight average and 5 years of age) placed in each pond. For providing of suitable water and nutrition, fish were fed by food containing rich protein (40%) with 3-5% body weight and maintained in water with 30-35 ppt salinity. The survey of sexual maturation was performed by sampling of sexual glands through year. There were four stages in dominant female broodstocks. This survey indicated that oocytes have emerged stage 1 (immature) from March to June, stage 2 (yolk vesicle) in September and stage 4 (yolk globule) in October. Three stages (first, second and third) of yolk formation in oocytes will occur but these stages take place in October, December and January respectively. It's obvious that oocytes will progress into the end of third stage (yolk formation) and then their growth was arrested. Ovum with 600 m diameter was observed when the water temperature declined less than 18 c and day time was short (from middle autumn to middle winter), on that time, fish were induced by hormone because lack of final maturation and ovulation, therefore, natural spawning was not occurred in pond condition. Furthermore, artificial propagation of mugil cephalus was occurred by hormonal induction. Hormonal induction was utilized by inject of many hormones (LHRH, Cph, HCG). Using different components of hormones and also their different doses obtained the best results from broodstock that the average ovum diameter was about 600 m. Several types hormones which were injected into gray mullet with two or several intermittent (24 h intervals) along with 20-25 c temperature and 30-35 ppt salinity. This condition can provide stage 4 maturity for fertilization. Totally (as whole), three intermittent fertilization was necessary for exiting of larva, larva production in first, second and third intermittents that were 2000, 2500 and 300 specimens respectively. Larva fed on chlorella algae and rotifera and they have maintained for 14-15 days. The results of obtainable research indicated the possibility of gray mullet broodstock production in cultural condition, artificial propagation and larva production. This research took place for the first time in north climate of Iran

    Global age-sex-specific fertility, mortality, healthy life expectancy (HALE), and population estimates in 204 countries and territories, 1950-2019 : a comprehensive demographic analysis for the Global Burden of Disease Study 2019

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    Background: Accurate and up-to-date assessment of demographic metrics is crucial for understanding a wide range of social, economic, and public health issues that affect populations worldwide. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 produced updated and comprehensive demographic assessments of the key indicators of fertility, mortality, migration, and population for 204 countries and territories and selected subnational locations from 1950 to 2019. Methods: 8078 country-years of vital registration and sample registration data, 938 surveys, 349 censuses, and 238 other sources were identified and used to estimate age-specific fertility. Spatiotemporal Gaussian process regression (ST-GPR) was used to generate age-specific fertility rates for 5-year age groups between ages 15 and 49 years. With extensions to age groups 10–14 and 50–54 years, the total fertility rate (TFR) was then aggregated using the estimated age-specific fertility between ages 10 and 54 years. 7417 sources were used for under-5 mortality estimation and 7355 for adult mortality. ST-GPR was used to synthesise data sources after correction for known biases. Adult mortality was measured as the probability of death between ages 15 and 60 years based on vital registration, sample registration, and sibling histories, and was also estimated using ST-GPR. HIV-free life tables were then estimated using estimates of under-5 and adult mortality rates using a relational model life table system created for GBD, which closely tracks observed age-specific mortality rates from complete vital registration when available. Independent estimates of HIV-specific mortality generated by an epidemiological analysis of HIV prevalence surveys and antenatal clinic serosurveillance and other sources were incorporated into the estimates in countries with large epidemics. Annual and single-year age estimates of net migration and population for each country and territory were generated using a Bayesian hierarchical cohort component model that analysed estimated age-specific fertility and mortality rates along with 1250 censuses and 747 population registry years. We classified location-years into seven categories on the basis of the natural rate of increase in population (calculated by subtracting the crude death rate from the crude birth rate) and the net migration rate. We computed healthy life expectancy (HALE) using years lived with disability (YLDs) per capita, life tables, and standard demographic methods. Uncertainty was propagated throughout the demographic estimation process, including fertility, mortality, and population, with 1000 draw-level estimates produced for each metric. Findings: The global TFR decreased from 2·72 (95% uncertainty interval [UI] 2·66–2·79) in 2000 to 2·31 (2·17–2·46) in 2019. Global annual livebirths increased from 134·5 million (131·5–137·8) in 2000 to a peak of 139·6 million (133·0–146·9) in 2016. Global livebirths then declined to 135·3 million (127·2–144·1) in 2019. Of the 204 countries and territories included in this study, in 2019, 102 had a TFR lower than 2·1, which is considered a good approximation of replacement-level fertility. All countries in sub-Saharan Africa had TFRs above replacement level in 2019 and accounted for 27·1% (95% UI 26·4–27·8) of global livebirths. Global life expectancy at birth increased from 67·2 years (95% UI 66·8–67·6) in 2000 to 73·5 years (72·8–74·3) in 2019. The total number of deaths increased from 50·7 million (49·5–51·9) in 2000 to 56·5 million (53·7–59·2) in 2019. Under-5 deaths declined from 9·6 million (9·1–10·3) in 2000 to 5·0 million (4·3–6·0) in 2019. Global population increased by 25·7%, from 6·2 billion (6·0–6·3) in 2000 to 7·7 billion (7·5–8·0) in 2019. In 2019, 34 countries had negative natural rates of increase; in 17 of these, the population declined because immigration was not sufficient to counteract the negative rate of decline. Globally, HALE increased from 58·6 years (56·1–60·8) in 2000 to 63·5 years (60·8–66·1) in 2019. HALE increased in 202 of 204 countries and territories between 2000 and 2019

    Global burden of 369 diseases and injuries in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019

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    Background: In an era of shifting global agendas and expanded emphasis on non-communicable diseases and injuries along with communicable diseases, sound evidence on trends by cause at the national level is essential. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) provides a systematic scientific assessment of published, publicly available, and contributed data on incidence, prevalence, and mortality for a mutually exclusive and collectively exhaustive list of diseases and injuries. Methods: GBD estimates incidence, prevalence, mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) due to 369 diseases and injuries, for two sexes, and for 204 countries and territories. Input data were extracted from censuses, household surveys, civil registration and vital statistics, disease registries, health service use, air pollution monitors, satellite imaging, disease notifications, and other sources. Cause-specific death rates and cause fractions were calculated using the Cause of Death Ensemble model and spatiotemporal Gaussian process regression. Cause-specific deaths were adjusted to match the total all-cause deaths calculated as part of the GBD population, fertility, and mortality estimates. Deaths were multiplied by standard life expectancy at each age to calculate YLLs. A Bayesian meta-regression modelling tool, DisMod-MR 2.1, was used to ensure consistency between incidence, prevalence, remission, excess mortality, and cause-specific mortality for most causes. Prevalence estimates were multiplied by disability weights for mutually exclusive sequelae of diseases and injuries to calculate YLDs. We considered results in the context of the Socio-demographic Index (SDI), a composite indicator of income per capita, years of schooling, and fertility rate in females younger than 25 years. Uncertainty intervals (UIs) were generated for every metric using the 25th and 975th ordered 1000 draw values of the posterior distribution. Findings: Global health has steadily improved over the past 30 years as measured by age-standardised DALY rates. After taking into account population growth and ageing, the absolute number of DALYs has remained stable. Since 2010, the pace of decline in global age-standardised DALY rates has accelerated in age groups younger than 50 years compared with the 1990–2010 time period, with the greatest annualised rate of decline occurring in the 0–9-year age group. Six infectious diseases were among the top ten causes of DALYs in children younger than 10 years in 2019: lower respiratory infections (ranked second), diarrhoeal diseases (third), malaria (fifth), meningitis (sixth), whooping cough (ninth), and sexually transmitted infections (which, in this age group, is fully accounted for by congenital syphilis; ranked tenth). In adolescents aged 10–24 years, three injury causes were among the top causes of DALYs: road injuries (ranked first), self-harm (third), and interpersonal violence (fifth). Five of the causes that were in the top ten for ages 10–24 years were also in the top ten in the 25–49-year age group: road injuries (ranked first), HIV/AIDS (second), low back pain (fourth), headache disorders (fifth), and depressive disorders (sixth). In 2019, ischaemic heart disease and stroke were the top-ranked causes of DALYs in both the 50–74-year and 75-years-and-older age groups. Since 1990, there has been a marked shift towards a greater proportion of burden due to YLDs from non-communicable diseases and injuries. In 2019, there were 11 countries where non-communicable disease and injury YLDs constituted more than half of all disease burden. Decreases in age-standardised DALY rates have accelerated over the past decade in countries at the lower end of the SDI range, while improvements have started to stagnate or even reverse in countries with higher SDI. Interpretation: As disability becomes an increasingly large component of disease burden and a larger component of health expenditure, greater research and developm nt investment is needed to identify new, more effective intervention strategies. With a rapidly ageing global population, the demands on health services to deal with disabling outcomes, which increase with age, will require policy makers to anticipate these changes. The mix of universal and more geographically specific influences on health reinforces the need for regular reporting on population health in detail and by underlying cause to help decision makers to identify success stories of disease control to emulate, as well as opportunities to improve. Funding: Bill & Melinda Gates Foundation. © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licens

    In-Depth Assessment of Local Sequence Alignment

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    Abstract. The overall procedure of searching local similarities among amino acid sequences using local alignment tool has been described in detail. Different phases of the alignment and use of available scoring matrices are explained. The update of scoring matrices based on new sequence information regularly take place over time based on the overall procedure assembled here in a single document. This document assists young scientists who seek simple references to understand step-by-step local alignment

    Improved lipid and biomass productivities in Chlorella vulgaris by differing the inoculation medium from the production medium

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    Improvement of biomass and lipid productivities is now one of the main concerns in commercialization of microalgae cultivation as a feedstock for algal biofuel production. Conventional photoautotrophic processes using well-studied and rich in oil strain of Chlorella vulgaris are not able to meet such demands. A new strategy of inoculating algae production medium with cells grown in a different medium from the production medium was proposed herein. More specifically, when SH4 was used as production medium and N8 was used as inoculation medium, biomass and lipid productivities increased by 2.33 folds and 1.44 fold, respectively, compared with when the production and inoculation media were the same, such as SH4. The findings of the present investigation showed that this cultivation scheme resulted in 52% increase in cell number and 54% increase in dry weight leading to improved productivities. Although by even considering this improvement, photoautotrophic cultivation of algae can hardly compete with the heterotrophic cultivation, the high cost of hydrocarbon supply required in large-scale heterotrophic processes marks the technique proposed in the present study as a promising approach for commercialization of algal biofuel production

    Construction and Characterization of a New Recombinant Vector to Remove Sulfate Repression of dsz Promoter Transcription in Biodesulfurization of Dibenzothiophene

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    Biodesulfurization (BDS) is an environmentally friendly desulfurizing process with the potential of replacing or adding to the current expensive technologies for sulfur removal from fossil fuels. The BDS, however, still suffers from low biocatalyst activity. One reason is repression of dsz promoter transcription in presence of inorganic sulfate that impedes translation of Dsz enzymes required for desulfurization pathway. One approach to solve this problem is replacing the native promoter with a new promoter that is no longer repressed. In this study, dsz genes from desulfurizing strain Rhodococcus sp. FUM94 was cloned in an alkane responsive promoter, pCom8, and expressed in Escherichia coli BL21 (DE3) as a host. The recombinant was not susceptible to inorganic sulfate in the culture medium. Desulfurizing activity of recombinant strain versus wild type indicated that in a sulfate containing medium, BDS yield of recombinant increased from 16.0% ± 0.9 to 34.0% ± 1.9% when dibenzothiophene (DBT) concentration (dissolved in ethanol) increased from 25 to 100 ppm. Also, 2-hydroxy biphenyl (2-HBP) production rate improved 8.5-fold (from 0.302 ± 0.020 to 2.57 ± 0.14 mmol 2-HBP (kg DCW)-1 h-1) at the same DBT concentration range. This is while no 2-HBP production was detected in FUM94 biphasic reaction. In a sulfate-free medium, wild type strain demonstrated desulfurization activity, but decreasing with the increase of DBT concentration dissolved in n-tetradecane. Whereas, the recombinant strain demonstrated increasing desulfurizing activity in a sulfate-containing high DBT concentration environment. Overall, the result of this molecular manipulation can be considered as a step forward toward commercialization of BDS technology
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