11,028 research outputs found

    Profile of cry from native Bacillus thuringiensis isolates and expression of cry1I

    Get PDF
    The characterization of 255 Bacillus thuringiensis isolates of Coorg, Sharavatti and BR hills, containing genes known to be active against coleopteran and lepidopteran insect species was done through PCR amplification using the specific and degenerate primers. The isolates were also tested for their insecticidal activity against Plutella xylostella. Among the coleopteran specific genes screened, the most predominant was cry1I gene which was present in 18 isolates at a frequency of 7.05%. cry1 gene was found to be most abundant (35.39%) among the lepidopteran specific genes. A variant of cry1I gene based on amplicon restriction fragment length polymorphism (ARFLP) was cloned into pTZ57R/T and subcloned in an expression vector pQE-30 after amplification of a 2169 bp DNA fragment of cry1I gene from B. thuringiensis DBT189, the sequence which showed 99% homology with known cry1Ia gene from B. thuringiensis subsp. kurstaki. There were six mismatches between the two amino acid sequences. The cry1I- type gene consisted of an open reading frame of 2124 bp that would encode for 720 amino acids. An expected band size of 81 kDa was observed after sodium dodecyl sulphate- polyacrylamide gel electrophoresis (SDS-PAGE) analysis indicating the expression of cry1I gene.Keywords: Bacillus thuringiensis, Plutella xylostella, ARFLP, cloning, SDS-PAGEAfrican Journal of Biotechnology Vol. 12(22), pp. 3545-356

    Design and Process control of Siemens polysilicon CVD reactor

    Get PDF
    The novelty in this paper is to develop a process control for the poly-silicon CVD reactor to achieve optimum productivity of Poly-silicon seed by controlling the process parameters. The production of ingot is done through Siemens process of decomposing Trichlorosilane by Chemical Vapor Deposition on slim tungsten rods. The hardware architecture proposed monitors and controls the systematic sequential stages furnishing dynamics of the plant at a high temperature around 1050°C-1100°C. The HMI communicates through NI's LabVIEW 8.6 package, alarming the user with Process mimic, Report generation, Data and Security management. The plant simulation is realized and verified with LabVIEW 8.6 Version and MATLab 7.5 software tools to obtain the effectiveness of proposed control technique. This GUI based SCADA handles likelihood of fault tolerance, ensuring risk controlled process with optimum productivity of poly-silicon by making system compliant to Industrial standards

    Sea level changes along the Indian coast: Observations and projections

    Get PDF
    Sea level changes can be of two types: (i) changes in the mean sea level and (ii) changes in the extreme sea level. The former is a global phenomenon while the latter is a regional phenomenon. Estimates of mean sea level rise made from past tide gauge data at selected stations along the coast of India indicate a rise of slightly less than 1 mm/year; however these estimates need to be corrected by including the rates of vertical land movements, whose measurements are not available at present. Simulation results of a regional climate model, HadRM2, were analysed for the northern Indian Ocean to provide the future scenarios of the occurrence of tropical cyclones in the Bay of Bengal for the period 2041-60. This model simulations consist of a control run with concentration of CO2 kept constant at 1990 levels and a perturbed run with transient increase in the concentrations of CO2 (GHG) according to the IS92a scenario for the period 2041-2060. The simulation results show increase in frequencies of tropical cyclones in the Bay, particularly intense events during the postmonsoon period, for the increased GHG run. A storm surge model was used to compute the surges associated with the cyclones generated by the climate model. The storm surge model was forced by the wind field from HadRM2 over the model domain and tides prescribed along the open boundary from a global tidal model. The frequency of high surges is found to be higher in the model run forced by winds from increased GHG run than in the model run forced by winds from the control run

    Perception des risques sanitaires dans le maraîchage à Abidjan, Côte d’Ivoire

    Get PDF
    Cette étude a été conduite pour évaluer le niveau de connaissance et de perception des risques sanitaires dans le secteur du maraîchage à Abidjan, à travers une enquête transversale. Le maraîchage est pratiqué à 77,98% par les hommes et à 22,02% par les femmes, qui sont pour la plupart des analphabètes (58,6%). Différents types de légumes sont produits à savoir les laitues (40,97%), laitues+autres légumes (32,12%) et autres légumes (26,9%). 73,4% des producteurs ne sont pas conscients des risques de contamination dus à leurs comportements contre 8,3% qui affirment reconnaître leur part de responsabilités dans la contamination des produits maraîchers. De manière préférentielle, 89,2% des exploitants agricoles utilisent des sacs en fil de coton pour le conditionnement des légumes frais qui sont transportés à 71% vers les points de vente au moyen de véhicules. En l’absence d’une éducation sanitaire fondée et des  interventions localement adaptées, les cultivateurs n’accordent pas une attention particulière à la prévention des risques sanitaires.© 2013 International Formulae Group. All rights reserved.Mots clés: Conception, fruits et légumes, contamination, maraîchage périurbain, comportement des maraîchers

    Capturing the Occult Central Retinal Artery Occlusion Using Optical Coherence Tomography

    Get PDF
    AIMS: To report spectral-domain optical coherence tomography (OCT) findings in cases of impending or occult central retinal artery occlusion (CRAO) in which a diagnosis other than CRAO was made on initial presentation. METHODS: Retrospective, observational case series of patients diagnosed with CRAO for whom on initial presentation fundal examination and OCT findings were deemed unremarkable and/or a diagnosis other than CRAO was made. OCT images from the initial presentation were then reviewed for evidence of inner retinal ischaemia. RESULTS: In total, 214 cases of CRAO were identified. Eleven patients (5.14%) had been given an alternative initial diagnosis at their first presentation in casualty and were included. The age range was 20–84 years and 81% (9/11) were male. On review of initial OCT imaging performed in casualty, all cases had evidence of inner retinal ischaemia. Conclusions: CRAO is an ophthalmic emergency which leads to vision loss which is often irreversible. Examination of the fundus may be normal early in the course of the disease and therefore a timely diagnosis may be missed. This case series reports the OCT findings of inner retinal ischaemia in patients with occult or impending CRAO which may aid in the early diagnosis and referral to stroke services

    Increasing prevalence of advanced colonic polyps in young patients undergoing colonoscopy in a referral academic hospital in Hong Kong

    Get PDF
    Aim: To investigate the distribution and frequency of advanced polyps over eight years. Methods: 6424 colonoscopies were reviewed during the study period 1998 to 2005. The study period was subdivided into period I: 1998 to 2001 and period II: 2002-2005. Results: 1856 polyps (33% advanced polyps) and 328 CRCs were detected. The mean ages of the patients with advanced polyps and cancer were 69.2 ± 12.0 and 71.6 ± 13.8 years, respectively. Advanced polyps were mainly left sided (59.5%). Advanced polyps were found in patients ≤ 60 years from 17.7% in period I to 26.3% in period II (P 0.05). Conclusion: Advanced polyps increased significantly in the younger male group in the most recent period and there seems to be a shift towards a proximal location. © 2007 WJG. All rights reserved.published_or_final_versio

    Telomere length regulation: coupling DNA end processing to feedback regulation of telomerase

    Get PDF
    The conventional DNA polymerase machinery is unable to fully replicate the ends of linear chromosomes. To surmount this problem, nearly all eukaryotes use the telomerase enzyme, a specialized reverse transcriptase that utizes its own RNA template to add short TG-rich repeats to chromosome ends, thus reversing their gradual erosion occurring at each round of replication. This unique, non-DNA templated mode of telomere replication requires a regulatory mechanism to ensure that telomerase acts at telomeres whose TG tracts are too short, but not at those with long tracts, thus maintaining the protective TG repeat cap at an appropriate average length. The prevailing notion in the field is that telomere length regulation is brought about through a negative feedback mechanism that counts TG repeat-bound protein complexes to generate a signal that regulates telomerase action. This review summarizes experiments leading up to this model and then focuses on more recent experiments, primarily from yeast, that begin to suggest how this counting mechanism might work. The emerging picture is that of a complex interplay between the conventional DNA replication machinery, DNA damage response factors, and a specialized set of proteins that help to recruit and regulate the telomerase enzyme
    corecore