300 research outputs found

    Green Fluorescent Protein (GFP) in Vector Systems Played Sense Role of Epigenetic in Plants

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    The green fluorescent protein (GFP) of jellyfish (_Aequorea victoria_) has significant advantages over other reporter genes, because expression can be detected in living cells without any substrates. Recently, epigenetic phenomena are important to consider in plant biotechnology experiments for elucidate unknown mechanism. Therefore, soybean immature cotyledons were generated embryogenesis cells and engineered with two different gene constructs (pHV and pHVS) using gene gun method. Both constructs contain a gene conferring resistance to hygromycin (_hpt_) as a selective marker and a modified glycinin (11S globulin) gene (_V3-1_) as a target. However, sGFP(_S65T_) as a reporter gene was used only in pHVS as a reporter gene for study the relation between using sGFP(_S65T_) and gene silencing phenomena. Fluorescence microscopic was used for screening after the selection of hygromycin, identified clearly the expression of sGFP(_S65T_) in the transformed soybean embryos bombarded with the pHVS construct. Protein analysis was used to detect gene expression overall seeds using SDS-PAGE. Percentage of gene down regulation was highly in pHV construct compared with pHVS. Thus, sGFP(_S65T_) as a reporter gene in vector system may be play useful role for transgenic evaluation and avoid gene silencing in plants for the benefit of plant transformation system

    Variation of Electrostatic Coupling and Investigation of Current Percolation Paths in Nanocrystalline Silicon Cross Transistors

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    Nanocrystalline silicon thin films are promising materials for the development of advanced Large Scale Integration compatible quantum-dot and single-electron charging devices. The films consist of nanometer-scale grains of crystalline silicon, separated by amorphous silicon or silicon dioxide grain boundaries up to a few nanometer thick. These films have been used to fabricate single-electron transistor and memory devices, where the grains form single-electron charging islands isolated by tunnel barriers formed by the grain boundaries. The grain boundary tunnel barrier isolating the grains is also of great importance, as this determines the extent of the electrostatic and tunnel coupling between different grains. These effects can lead to the nanocrystalline silicon thin film behaving as a system of coupled quantum dots.& more..

    Detection of Most Congested Roads in Khartoum City Center using Geographical Information Systems Methods

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    The aim of this research is to Detect the Most Congested Roads in Khartoum City Center by studying the different causes of traffic congestion using GIS methods . Spatial and descriptive data of the congestion causes have been collected In the last three months, site plan, traffic plan ,random parking, bus lines and bus stations, natural and artificial obstacles ,entrance and exit of study area. Geographical database is created for geometrical analysis, to find out the most affected roads. This helps in developing economical solutions to the problem of traffic congestion

    Rare Coexistence Of Benign Renal Oncocytoma And Renal Cell Carcinoma

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    The coexistence of two tumors in a single person is not common. Finding two tumors in a single organ is rare. We are reporting a 65 years old male who presented with a long history of left loin pain. Clinical examination was unremarkable apart from hypertension. The histopathology of intraabdominal mass seen on exploration of abdomen revealed oncocytoma and renal cell carcinoma.. Keywords: contralateral, nephrectomy, multifocality, hematuria, perinephric. Sudan Journal of Medical Sciences Vol. 3 (2) 2008: pp. 167-17

    ENHANCEMENT OF ADVENTITIOUS SHOOT REGENERATION IN SESAME (SESAMUM INDICUM L.) CULTIVAR PROMO KY USING ETHYLENE INHIBITORS

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    Ethylene produced by tissue, callus and plantlets in closed vessels may lead to abnormal plantlet growth and branching in vitro. Silver nitrate (AgNO3) and Cobalt chloride (CoCl2) are known as ethylene inhibitors. Therefore, the objective of this study was to evaluate the in vitro regeneration capacity of sesame cultivar Promo KY when exposed to culture media containing ethylene inhibitors. A protocol is presented for direct adventitious shoot organogenesis and complete plant regeneration. MS medium enriched with 1.0 mg/L Benzyl adenine (BA) induced adventitious shoot in axenic seedling-derived shoot tips. Addition of ethylene inhibitors AgNO3 (0.5- 5.0 mg/L) enhanced number of shoots from 2.7 to 3.7 shoot/explant as well as shoot length from 1.3 to 2.9 cm . In the case of a medium comprising of MS salts with Naphthyl-Acetic Acid (NAA) 0.05 mg/L, 63 root/explant was observed and root emergence occur after 25 days of culture. Addition of 3.0 mg/L AgNO3 improved root initiation to 79 root/explants and root emerged after 14 days. Addition of 5.0 mg/L CoCl2 increase the root length from 3.5 cm to 17 cm. These promotive effects may result from a reduction in ethylene concentration or inhibition of ethylene action. The results found in this study may be used to improve the multiple shoot and rooting efficiency of Sesame cultivars and possibly of other plant species

    Effect of Growth Regulators on In Vitro Morphogenic Response of Boscia senegalensis (Pers.) Lam. Poir. Using Mature Zygotic Embryos Explants

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    The percent study describes the in vitro responses of mature zygotic embryos of Boscia senegalensis to different concentrations (0.0–5.0 mg/L) of 6-benzyladnine (BA), Thidiazuron (TDZ), α-Naphthalene acetic acid (NAA), and 2, 4-Dichlorophenoxyacetic acid (2, 4-D) supplemented on Murashige and Skoog medium (MS). The plant growth regulators (PGRs) were considerably affected the morphogenetic responses. BA produced adventitious shoots through two ways: direct organogenesis and auxiliary shoot formation. Both 2, 4-D and TDZ tend to produce callus, whereas NAA improve the development of embryos to seedlings. Maximum number of shoots/explant (14.8 ± 0.6) was obtained on MS medium supplemented with 3.0 mg/L BA. 67.0% of excised shoots were rooted either on 1/2 MS medium augmented with or without 0.25 mg/L IBA. The highest number of roots (1.2 ± 0.4) and root length (0.5 ± 0.2 cm) was produced on 0.25 mg/L IBA-containing medium. Regenerated plants were successfully acclimatized and transferred to the green house with 70% survival rate. All the plants appeared morphologically uniform with normal growth pattern. A rapid (30 days), efficient and without subculturing protocol for in vitro regeneration of B. senegalensis was developed

    Epidemiology of strongyle nematode infections and first report of benzimidazole resistance in Haemonchus contortus in goats in South Darfur State, Sudan

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    Background Since pastoralists in South Darfur, Sudan, had complained about lack of albendazole (ABZ) efficacy to control nematodes in goats, the frequency of infection with gastrointestinal helminths was studied before in vivo faecal egg count reduction tests (FECRT) were conducted using ABZ orally either at the dose recommended for sheep, 5 mg/kg body weight (bw) or at 10 mg/kg bw. Experiments included goats naturally infected with gastrointestinal nematodes or experimentally infected with local Haemonchus contortus isolates. Three study areas (Nyala, Beleil and Kass) were visited in autumn or winter. Results Out of 478 screened goats, 82.4% were infected with gastrointestinal helminths and 82% were shedding eggs of strongyle nematodes with 90% of the strongyle larvae representing Haemonchus spp. A FECRT using naturally infected goats (n = 225: 71 untreated, 104 and 50 treated with 5 and 10 mg ABZ/kg bw, respectively) detected reduced ABZ efficacy in Nyala and Kass. Paired and unpaired FECRT calculations detected reductions of 72–92% with samples taken at 8 days post treatment with 5 mg ABZ/kg bw and of 85–94% with 10 mg ABZ/kg bw. The FECRT based on day 14 post treatment samples showed reductions of 69–77% with 5 mg/kg and of 75–87% with 10 mg ABZ/kg bw. In Beleil, ABZ efficacy was 95%. In the egg hatch test EC50 values for Nyala and Kass ranged from 0.12–0.24 μg thiabendazole/ml, corresponding to benzimidazole resistant phenotypes. Only Haemonchus spp. larvae were present after treatments in coprocultures. When the efficacy was evaluated experimentally using isolates of H. contortus from Nyala and Kass, the 5 mg ABZ/kg dose revealed reductions of 76–78% on day 8 and of 62–70% on day 14 with the unpaired method. Using 10 mg ABZ/kg, the FECR was still only 77–82%. Conclusions Both, in vivo and in vitro methods detected resistant H. contortus populations in goats from South Darfur State. The time point 14 days post treatment was more sensitive for detection of ABZ resistance than 8 days post treatment. This is the first report on the occurrence of anthelmintic resistance in Sudan confirming that anthelmintic resistance selection is occurring in African subsistence farming systems

    Single donor ionization energies in a nanoscale CMOS channel

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    One consequence of the continued downwards scaling of transistors is the reliance on only a few discrete atoms to dope the channel, and random fluctuations of the number of these dopants is already a major issue in the microelectonics industry. While single-dopant signatures have been observed at low temperature, studying the impact of only one dopant up to room temperature requires extremely small lengths. Here, we show that a single arsenic dopant dramatically affects the off-state behavior of an advanced microelectronics field effect transistor (FET) at room temperature. Furthermore, the ionization energy of this dopant should be profoundly modified by the close proximity of materials with a different dielectric constant than the host semiconductor. We measure a strong enhancement, from 54meV to 108meV, of the ionization energy of an arsenic atom located near the buried oxide. This enhancement is responsible for the large current below threshold at room temperature and therefore explains the large variability in these ultra-scaled transistors. The results also suggest a path to incorporating quantum functionalities into silicon CMOS devices through manipulation of single donor orbitals
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