160 research outputs found

    16S rRNA based identification of _Aeromonas sp. kumar_ by constructing phylogenetic tree and identification of regulatory elements from the harmful Red Tide bloom, Gulf of Mannar

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    A bacterial strain, designated _Aeromonas sp. kumar_, was isolated from a water sample collected from Red tide Bloom occurred in the region of Gulf of Mannar region, Puthumadam Coast, India and the strain was identified using 16S rRNA based identification. During the sample collection, microbiology analysis was done to study the morphology of the bacteria. Pure culture of strain was maintained through out the study. DNA was isolated and sequenced using 16S rRNA primers. A length of 1452 nucleotide was sequenced and was put in public data base for obtaining accession number. The sequence was studied using MEGA 4, to estimate the evolutionary distances and to construct the Phylogenetic tree. Along with that Regulatory elements and Transcription factors were studied using BPROM tool. In genetics, a promoter is a region of DNA that facilitates the transcription of a particular gene. Promoters are typically located near the genes they regulate, on the same strand and upstream (towards the 5' region of the sense strand). The objective of the study is to predict the regulatory elements which are -10 box, -35box and three Transcription Factors (rpoD19, rpoD17 and araC) with their binding sites in the 16S rRNA gene of _Aeromonas sp. kumar_. The gene bank accession number for 16S rRNA gene of _Aeromonas sp. kumar_ is FJ896014

    Evaluation of biosorption potential of Gracilaria corticata for the removal of hexavalent chromium from aqueous solutions using response surface methodology

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    In this study, the biosorption of chromium (VI) on Gracilaria corticata biomass marine algae, was investigated in a batch and continious system. The influence of process parameters including sorbent size (0.176 - 1.503 mm), sorbent dosage (3 -7 g/l), temperature (25 - 45°C), contact time (2 - 10 hrs) and agitation speed (50 - 250 rpm) on the sorption of chromium (VI) were performed using a full factorial central composite design (CCD). This result of the studies indicates that the optimum biosorption conditions of sorbent size, sorbent dosage, temperature, contact time  and agitation speed were 0.5284 mm, 5.12 g, 35°C , 2 hours 58 minutes and 140 rpm, respectively. A higher value coefficient of determination R2 0.9799 evidenced the fitness of response surface methodology. The Langmuir and Freundlich isotherm models were applied to the equilibrium data. The Langmuir adsorption model was better than the other model. The maximum adsorption capacity of Gracilaria corticata was found to be 62.5 mg/g. The thermodynamic parameters like enthalpy (ΔH◦) and entropy (ΔS◦) were 34.57 (kJ/mol) and 0.1308 (kJ/mol K) respectively. The results showed that the biosorption of chromium (VI) by Gracilaria corticata is more endothermic and spontaneous

    RanDumb: a simple approach that questions the efficacy of continual representation learning

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    We propose RanDumb to examine the efficacy of continual representation learning. RanDumb embeds raw pixels using a fixed random transform which approximates an RBF-Kernel, initialized before seeing any data, and learns a simple linear classifier on top. We present a surprising and consistent finding: RanDumb significantly outperforms the continually learned representations using deep networks across numerous continual learning benchmarks, demonstrating the poor performance of representation learning in these scenarios. RanDumb stores no exemplars and performs a single pass over the data, processing one sample at a time. It complements GDumb [39], operating in a lowexemplar regime where GDumb has especially poor performance. We reach the same consistent conclusions when RanDumb is extended to scenarios with pretrained models replacing the random transform with pretrained feature extractor. Our investigation is both surprising and alarming as it questions our understanding of how to effectively design and train models that require efficient continual representation learning, and necessitates a principled reinvestigation of the widely explored problem formulation itself. Our code is available here

    Developing and evaluating a five minute phishing awareness video

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    Confidence tricksters have always defrauded the unwary. The computer era has merely extended their range and made it possible for them to target anyone in the world who has an email address. Nowadays, they send phishing messages that are specially crafted to deceive. Improving user awareness has the potential to reduce their effectiveness. We have previously developed and empirically-validated phishing awareness programmes. Our programmes are specifically designed to neutralize common phish-related misconceptions and teach people how to detect phishes. Many companies and individuals are already using our programmes, but a persistent niggle has been the amount of time required to complete the awareness programme. This paper reports on how we responded by developing and evaluating a condensed phishing awareness video that delivered phishing awareness more efficiently. Having watched our video, participants in our evaluation were able to detect phishing messages significantly more reliably right after watching the video (compared to before watching the video). This ability was also demonstrated after a retention period of eight weeks after first watching the video

    Corrosion Protection of Steel Using Nonanomalous Ni-Zn-P Coatings

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    A novel technique for obtaining nonanomalous Ni-Zn-P coatings with high Ni content (74 wt % as compared to 15-20 wt % in the conventional plating method) has been developed. These coatings show promise as a replacement for Cd in sacrificially protecting steel. Ni-Zn-P coatings were deposited using an electroless method from a solution containing NiSO4, complexing agent and ammonium chloride. Varying the concentration of ZnSO4 in the bath controls the final amount of Zn in the deposit. The Zn content in the coating was optimized based on the corrosion resistance of the final deposit. Coatings with 16.2 wt % Zn were found to display a potential of –0.652 V vs. SCE that is more electronegative to steel and hence can be used as a sacrificial coating for the protection of steel. Deposition parameters like pH and temperature have been optimized based on composition of the coating and the surface morphology. Corrosion studies in corroding media show that Ni-Zn-P coatings obtained using the electroless method show a higher barrier resistance and better stability as compared to cadmium coatings

    O 2 Reduction on Graphite and Nitrogen-Doped Graphite: Experiment and Theory

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    An experimental and theoretical study of electroreduction of oxygen to hydrogen peroxide is presented. The experimental measurements of nitrided Ketjenblack indicated an onset potential for reduction of approximately 0.5 V (SHE) compared to the onset potential of 0.2 V observed for untreated carbon. Quantum calculations on cluster models of nitrided and un-nitrided graphite sheets show that carbon radical sites formed adjacent to substitutional N in graphite are active for O 2 electroreduction to H 2 O 2 via and adsorbed OOH intermediate. The weak catalytic effect of untreated carbon is attributed to weaker bonding of OOH to the H atom-terminated graphite edges. Substitutional N atoms that are far from graphite sheet edges will be active, and those that are close to the edges will be less active. Interference from electrochemical reduction of H atoms on the reactive sites is considered, and it is shown that in the potential range of H 2 O 2 formation the reactive sites are not blocked by adsorbed H atoms

    The effects of the 2004 Tsunami on mainland India and the Andaman and Nicobar Islands

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    Mortality from the tsunamis was high, with more than 7,000 deaths in the Nicobar group alone (the final number may never be known as many indigenous people on remote islands may have perished). On the mainland, there were a similar number of fatalities ; The greatest losses were in fishing communities although the waves destroyed roads, jetties, other basic infrastructure and entire villages; There was major damage to the coastal resources of southeast India, particularly to mangrove and coastal forests. On the Andaman and Nicobar Islands there was considerable damage to the coral reefs and beaches, as well as the forests; The earthquakes changed the bathymetry of the coral reefs and coasts of the Andaman and Nicobars: reefs in the South Andamans to the Nicobars subsided by 1 - 3 metres; many reefs in the northern Andamans were uplifted out of the water and died; and some beaches have almost disappeared, while new beaches have formed; There was major damage to large areas of coral reefs of the Andamans and Nicobars, particularly due to debris being washed off the land and smothering by sediments; Mainland coral reefs in the Gulf of Mannar and elsewhere suffered very minor, localised damage. Many mainland beaches were seriously eroded; and The affected reefs are expected to recover within 5-10 years, if there is effective resource management and enforcement of legislation controlling destructive fishing, coral mining, over-harvesting of reef resources, coastal development, sedimentation and pollution
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