134 research outputs found

    A deep gold mine metagenome as a source of novel esterases.

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    New sources of enzymes for biotechnological applications are continually being sought for. While diverse microbial ecosysyems have been demonstrated in the deep subsurfaces, deep mines provide easy access to these specialist communities. Therefore, the aim of this study was to assess a deep mine biofilm as a source of novel esterase enzymes. Biofilm was collected from the Beatrix Mine in South Africa, at a depth of 808 m. Assessment of the diversity revealed a group of previously uncultured bacteria and archaea. A metagenome library was screened for esterolytic activity, producing two esterolytic clones: a phospholipase patatin protein and an isochorismatase family protein. The isochorismatase family protein contained the catalytic Asp and Cys but not the Arg, which is considered as important for catalysis. The patatin showed 55% similarity to its closest relative; the patatin family protein from Plesiocystis pacifica. The expressed patatin displayed a preference for the C6 ester and was maximally active at pH 8 and 30°C. This study reported that screening of a relatively small metagenome library from the deep mine biofilm provided two esterolytic clones, which differed from their known counterparts. This indicates that the deep mine ecosystems contain an untapped resource of novel and potentially useful enzymes which may have applications in chemical syntheses

    Hubungan Antara Tingkat Stres dengan Siklus Menstruasi pada Mahasiswi di Pesma K.H Mas Mansyur Universitas Muhammadiyah Surakarta

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    Every human being will experience what is called adolescence. Adolescence itself is a dynamic phase of development in life. In adolescent girls begins with biological changes, one of which is menstruation. Menstruation is the decay of the uterine wall or the process of bleeding from the female reproductive system. Every woman has a different or different menstrual cycle. The difference of this cycle is determined by some factors, one of them is stress which is the cause of the menstrual disturbance. The stress itself is a physical or psychological reaction towards some demands which causes some strains and disrupts the stability of daily life. This condition causes the feelings of worries, anger, and frustration. to find out the strength of the relationship between the degree of stress and the menstrual cycle. The kind of this study is observational by using descriptive analytics, with cross-sectional approach. In addition, this study is conducted in Pesma K.H Mas Mansyur Universitas Muhammadiyah Surakarta in January. Moreover, the sampling technique used is purposive sampling in which the respondents are 150 students. The data is taken by using questionnaires about stress and menstrual cycle. The results of the data analysis using chi square test showed that the p-value was 0.002<0.05, which meant that there was a very significant relationship between the degree of stress and the menstrual cycle. The OR value was 3.596, the value of lower CI was 1.659, and the value of upper CI was 7.798. There is a very significant relationship between the degree of stress and the menstrual cycle at students in Pesma K.H Mas Mansur Universitas Muhammadiyah Surakarta

    Collusion through Joint R&D: An Empirical Assessment

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    This paper tests whether upstream R&D cooperation leads to downstream collusion. We consider an oligopolistic setting where firms enter in research joint ventures (RJVs) to lower production costs or coordinate on collusion in the product market. We show that a sufficient condition for identifying collusive behavior is a decline in the market share of RJV-participating firms, which is also necessary and sufficient for a decrease in consumer welfare. Using information from the US National Cooperation Research Act, we estimate a market share equation correcting for the endogeneity of RJV participation and R&D expenditures. We find robust evidence that large networks between direct competitors – created through firms being members in several RJVs at the same time – are conducive to collusive outcomes in the product market which reduce consumer welfare. By contrast, RJVs among non-competitors are efficiency enhancing

    Complex Effects of Cytochrome P450 Monooxygenase on Purple Membrane and Bacterioruberin Production in an Extremely Halophilic Archaeon: Genetic, Phenotypic, and Transcriptomic Analyses

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    Halophilic archaea are known to produce a diverse array of pigments for phototrophy and photoprotection. The aim of this paper was to determine the role of a Halobacterium gene encoding the predicted cytochrome P450 monooxygenase (CYP174A1) in pigment synthesis through a combined genetic, phenotypic, and transcriptomic approach. We report on the observed phenotype changes [increased bacterioruberin levels and the loss of purple membrane (PM)] between the Halobacterium salinarum R1 and its CYP174A1-deletion mutant. In addition, we report on the whole-genome DNA microarray analysis, which supports the phenotype of PM loss. This work expands our understanding of the bop-gene regulon, and its relation to carotenoid biosynthesis, and sheds light on our broader understanding of the role (s) of CYP174A1 in archaeal pigment synthesis. To date, this is the first study in which the physiological role of any cytochrome P450 monooxygenase (CYP450) in extremely halophilic archaea has been reported

    Expected Performance of the ATLAS Experiment - Detector, Trigger and Physics

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    A detailed study is presented of the expected performance of the ATLAS detector. The reconstruction of tracks, leptons, photons, missing energy and jets is investigated, together with the performance of b-tagging and the trigger. The physics potential for a variety of interesting physics processes, within the Standard Model and beyond, is examined. The study comprises a series of notes based on simulations of the detector and physics processes, with particular emphasis given to the data expected from the first years of operation of the LHC at CERN

    Sequence of the hyperplastic genome of the naturally competent Thermus scotoductus SA-01

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    <p>Abstract</p> <p>Background</p> <p>Many strains of <it>Thermus </it>have been isolated from hot environments around the world. <it>Thermus scotoductus </it>SA-01 was isolated from fissure water collected 3.2 km below surface in a South African gold mine. The isolate is capable of dissimilatory iron reduction, growth with oxygen and nitrate as terminal electron acceptors and the ability to reduce a variety of metal ions, including gold, chromate and uranium, was demonstrated. The genomes from two different <it>Thermus thermophilus </it>strains have been completed. This paper represents the completed genome from a second <it>Thermus </it>species - <it>T. scotoductus</it>.</p> <p>Results</p> <p>The genome of <it>Thermus scotoductus </it>SA-01 consists of a chromosome of 2,346,803 bp and a small plasmid which, together are about 11% larger than the <it>Thermus thermophilus </it>genomes. The <it>T. thermophilus </it>megaplasmid genes are part of the <it>T. scotoductus </it>chromosome and extensive rearrangement, deletion of nonessential genes and acquisition of gene islands have occurred, leading to a loss of synteny between the chromosomes of <it>T. scotoductus and T. thermophilus</it>. At least nine large inserts of which seven were identified as alien, were found, the most remarkable being a denitrification cluster and two operons relating to the metabolism of phenolics which appear to have been acquired from <it>Meiothermus ruber</it>. The majority of acquired genes are from closely related species of the Deinococcus-Thermus group, and many of the remaining genes are from microorganisms with a thermophilic or hyperthermophilic lifestyle. The natural competence of <it>Thermus scotoductus </it>was confirmed experimentally as expected as most of the proteins of the natural transformation system of <it>Thermus thermophilus </it>are present. Analysis of the metabolic capabilities revealed an extensive energy metabolism with many aerobic and anaerobic respiratory options. An abundance of sensor histidine kinases, response regulators and transporters for a wide variety of compounds are indicative of an oligotrophic lifestyle.</p> <p>Conclusions</p> <p>The genome of <it>Thermus scotoductus </it>SA-01 shows remarkable plasticity with the loss, acquisition and rearrangement of large portions of its genome compared to <it>Thermus thermophilus</it>. Its ability to naturally take up foreign DNA has helped it adapt rapidly to a subsurface lifestyle in the presence of a dense and diverse population which acted as source of nutrients. The genome of <it>Thermus scotoductus </it>illustrates how rapid adaptation can be achieved by a highly dynamic and plastic genome.</p
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