2 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

    Mapping routine measles vaccination in low- and middle-income countries

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    The safe, highly effective measles vaccine has been recommended globally since 1974, yet in 2017 there were more than 17 million cases of measles and 83,400 deaths in children under 5 years old, and more than 99% of both occurred in low- and middle-income countries (LMICs)1–4. Globally comparable, annual, local estimates of routine first-dose measles-containing vaccine (MCV1) coverage are critical for understanding geographically precise immunity patterns, progress towards the targets of the Global Vaccine Action Plan (GVAP), and high-risk areas amid disruptions to vaccination programmes caused by coronavirus disease 2019 (COVID-19)5–8. Here we generated annual estimates of routine childhood MCV1 coverage at 5 × 5-km2 pixel and second administrative levels from 2000 to 2019 in 101 LMICs, quantified geographical inequality and assessed vaccination status by geographical remoteness. After widespread MCV1 gains from 2000 to 2010, coverage regressed in more than half of the districts between 2010 and 2019, leaving many LMICs far from the GVAP goal of 80% coverage in all districts by 2019. MCV1 coverage was lower in rural than in urban locations, although a larger proportion of unvaccinated children overall lived in urban locations; strategies to provide essential vaccination services should address both geographical contexts. These results provide a tool for decision-makers to strengthen routine MCV1 immunization programmes and provide equitable disease protection for all children
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