45 research outputs found

    Study of genetic diversity in Sudanese sesame (Sesamum indicum L.) germplasm using random amplified polymorphic DNA (RAPD) markers

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    The random amplified polymorphic DNA (RAPD) markers were used to assess genetic diversity in Sesame indicum (L.). RAPD technique was carried out in a set of 10 sesame germplasm collected from different regions of Sudan. A total of 64 polymorphisms (6.4 polymorphic markers per primer) out of 75 reproducible products (7.5 fragments per primer) were obtained from the 10 primers used. The number of bands per primer ranged from 4 to 13, whereas the number of polymorphic bands ranged from 3 to12, corresponding to 66.6% of the amplification products. Low level of genetic similarity was observed in the collected accessions. Unique bands were observed with the 10 primers. UPGMA clustering resulted in two major groups

    Production of salinity tolerant Nile tilapia, Oreochromis niloticus through traditional and modern breeding methods: II. Application of genetically modified breeding by introducing foreign DNA into fish gonads

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    This study was conducted to produce a salinity tolerant Nile tilapia, Oreochromis niloticus through genetically modified breeding by introducing a fragmented purified DNA isolated from sea bream, Sparus aurata or Artemia, Artemia salina into the gonads. The results showed a significantimprovement (P . 0.05) in most of the growth performance and feed utilization parameters of genetically modified O. niloticus treated with sea bream-DNA and reared at different salinity levels up to 16 ppt compared to both genetically modified O. niloticus treated with Artemia-DNA and the control fish reared at the same salinity levels. Genetically modified O. niloticus treated with Artemia-DNA reared at 32 ppt, had displayed better traits results (P. 0.05) compared to the other fish within the same salinity level. Furthermore, genetically modified O. niloticus treated with sea bream-DNA showed a silver color covering all the body and no dark vertical bands. The results of the random amplified polymorphic DNA (RAPD) fingerprinting showed highly genetic polymorphic percentage (35.95%) among fish receiving foreign DNA and their control using different random primers. The results of the present work suggested that, hyper-saline genetically modified O. niloticus with higher growth rate can be producedusing a feasible and fast methodology.Key words: Salinity tolerance, Oreochromis niloticus, productive performance, genetically modified, DNA transfer

    Sediment-laden sea ice in southern Hudson Bay: Entrainment, transport, and biogeochemical implications

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    During a research expedition in Hudson Bay in June 2018, vast areas of thick (>10 m), deformed sediment-laden sea ice were encountered unexpectedly in southern Hudson Bay and presented difficult navigation conditions for the Canadian Coast Guard Ship Amundsen. An aerial survey of one of these floes revealed a maximum ridge height of 4.6 m and an average freeboard of 2.2 m, which corresponds to an estimated total thickness of 18 m, far greater than expected within a seasonal ice cover. Samples of the upper portion of the ice floe revealed that it was isothermal and fresh in areas with sediment present on the surface. Fine-grained sediment and larger rocks were visible on the ice surface, while a pronounced sediment band was observed in an ice core. Initial speculation was that this ice had formed in the highly dynamic Nelson River estuary from freshwater, but δ^{18}O isotopic analysis revealed a marine origin. In southern Hudson Bay, significant tidal forcing promotes both sediment resuspension and new ice formation within a flaw lead, which we speculate promotes the formation of this sediment-laden sea ice. Historic satellite imagery shows that sediment-laden sea ice is typical of southern Hudson Bay, varying in areal extent from 47 to 118 km2 during June. Based on an average sediment particle concentration of 0.1 mg mL^{–1} in sea ice, an areal extent of 51,924 km2 in June 2018, and an estimated regional end-of-winter ice thickness of 1.5 m, we conservatively estimated that a total sediment load of 7.8 × 106 t, or 150 t km^{–2}, was entrained within sea ice in southern Hudson Bay during winter 2018. As sediments can alter carbon concentrations and light transmission within sea ice, these first observations of this ice type in Hudson Bay imply biogeochemical impacts for the marine system

    Global, regional, and national incidence, prevalence, and mortality of HIV, 1980–2017, and forecasts to 2030, for 195 countries and territories: a systematic analysis for the Global Burden of Diseases, Injuries, and Risk Factors Study 2017

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    Background Understanding the patterns of HIV/AIDS epidemics is crucial to tracking and monitoring the progress of prevention and control efforts in countries. We provide a comprehensive assessment of the levels and trends of HIV/AIDS incidence, prevalence, mortality, and coverage of antiretroviral therapy (ART) for 1980–2017 and forecast these estimates to 2030 for 195 countries and territories. Methods We determined a modelling strategy for each country on the basis of the availability and quality of data. For countries and territories with data from population-based seroprevalence surveys or antenatal care clinics, we estimated prevalence and incidence using an open-source version of the Estimation and Projection Package—a natural history model originally developed by the UNAIDS Reference Group on Estimates, Modelling, and Projections. For countries with cause-specific vital registration data, we corrected data for garbage coding (ie, deaths coded to an intermediate, immediate, or poorly defined cause) and HIV misclassification. We developed a process of cohort incidence bias adjustment to use information on survival and deaths recorded in vital registration to back-calculate HIV incidence. For countries without any representative data on HIV, we produced incidence estimates by pulling information from observed bias in the geographical region. We used a re-coded version of the Spectrum model (a cohort component model that uses rates of disease progression and HIV mortality on and off ART) to produce age-sex-specific incidence, prevalence, and mortality, and treatment coverage results for all countries, and forecast these measures to 2030 using Spectrum with inputs that were extended on the basis of past trends in treatment scale-up and new infections. Findings Global HIV mortality peaked in 2006 with 1·95 million deaths (95% uncertainty interval 1·87–2·04) and has since decreased to 0·95 million deaths (0·91–1·01) in 2017. New cases of HIV globally peaked in 1999 (3·16 million, 2·79–3·67) and since then have gradually decreased to 1·94 million (1·63–2·29) in 2017. These trends, along with ART scale-up, have globally resulted in increased prevalence, with 36·8 million (34·8–39·2) people living with HIV in 2017. Prevalence of HIV was highest in southern sub-Saharan Africa in 2017, and countries in the region had ART coverage ranging from 65·7% in Lesotho to 85·7% in eSwatini. Our forecasts showed that 54 countries will meet the UNAIDS target of 81% ART coverage by 2020 and 12 countries are on track to meet 90% ART coverage by 2030. Forecasted results estimate that few countries will meet the UNAIDS 2020 and 2030 mortality and incidence targets. Interpretation Despite progress in reducing HIV-related mortality over the past decade, slow decreases in incidence, combined with the current context of stagnated funding for related interventions, mean that many countries are not on track to reach the 2020 and 2030 global targets for reduction in incidence and mortality. With a growing population of people living with HIV, it will continue to be a major threat to public health for years to come. The pace of progress needs to be hastened by continuing to expand access to ART and increasing investments in proven HIV prevention initiatives that can be scaled up to have population-level impact

    The heat shock response in neurons and astroglia and its role in neurodegenerative diseases

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