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1.
Páraic ó Cuív Rajesh Gupta Hareshwar P. Goswami Mark Morrison 《Applied and environmental microbiology》2013,79(19):6173-6175
Clostridium thermocellum encodes a cellulosomal, modular, and thermostable serine protease inhibitor (serpin), PinA. PinA stability but not inhibitory activity is affected by the Fn(III) and Doc(I) domains, and PinA is a broad inhibitor of subtilisin-like proteases and may play a key role in protecting the cellulosome from protease attack. 相似文献
2.
A microcomputer mainframe linked system is described which allows video camera data capture and storage of one-dimensional whole-cell protein electrophoresis gel images, processing of normalized traces to produce a similarity matrix, and analysis of the matrix using the commercial cluster analysis program CLUSTAN. A new similarity coefficient is introduced which takes into account both band position and intensity. Forty-five strains of Haemophilus influenzae, including the eight biotypes and six serotypes, were analyzed using this system. Results demonstrated groupings which are consistent with known genetic relationships. 相似文献
3.
Atrial natriuretic factor alters autonomic interactions in the control of heart rate in conscious rats 总被引:2,自引:0,他引:2
U Ackermann J Khanna T G Irizawa 《Canadian journal of physiology and pharmacology》1988,66(7):930-936
Regulation of heart rate was studied in rats receiving either i.v. saline at 64 microL/min or synthetic 28-residue rat atrial natriuretic peptide (ANF) at a dose sufficient to decrease mean arterial blood pressure by 10%. Autonomic influences were deduced from steady-state heart rate responses of each group to propranolol, atropine, or propranolol and atropine combined. A multiplicative model of heart rate control was used to derive quantitatively from the data the modulation of intrinsic heart rate by sympathetic and parasympathetic mechanisms. Animals receiving ANF showed a lower heart rate than control animals. This relative bradycardia was abolished by atropine. Blocking of sympathetic effects with propranolol had no effect on basal heart rate in either group, and atropinization led to significant increases in heart rate in both groups of rats. Mathematical analysis of the results showed that the bradycardia produced by ANF was due predominantly to a reduced intrinsic heart rate and to enhanced vagal inhibition of postganglionic sympathetic activity. Parasympathetic contribution to heart rate in the absence of sympathetic activity was negligible in control rats and small during ANF. We conclude that the major influences of ANF on heart rate control are a decrease of intrinsic heart rate and enhanced parasympathetic inhibition of postganglionic presynaptic sympathetic activity. 相似文献
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5.
Rajesh Narendran William G. Frankle Neale S. Mason Matthew F. Muldoon Bita Moghaddam 《PloS one》2012,7(10)
Studies in rodents indicate that diets deficient in omega-3 polyunsaturated fatty acids (n–3 PUFA) lower dopamine neurotransmission as measured by striatal vesicular monoamine transporter type 2 (VMAT2) density and amphetamine-induced dopamine release. This suggests that dietary supplementation with fish oil might increase VMAT2 availability, enhance dopamine storage and release, and improve dopamine-dependent cognitive functions such as working memory. To investigate this mechanism in humans, positron emission tomography (PET) was used to measure VMAT2 availability pre- and post-supplementation of n–3 PUFA in healthy individuals. Healthy young adult subjects were scanned with PET using [11C]-(+)-α-dihydrotetrabenzine (DTBZ) before and after six months of n–3 PUFA supplementation (Lovaza, 2 g/day containing docosahexaenonic acid, DHA 750 mg/d and eicosapentaenoic acid, EPA 930 mg/d). In addition, subjects underwent a working memory task (n-back) and red blood cell membrane (RBC) fatty acid composition analysis pre- and post-supplementation. RBC analysis showed a significant increase in both DHA and EPA post-supplementation. In contrast, no significant change in [11C]DTBZ binding potential (BPND) in striatum and its subdivisions were observed after supplementation with n–3 PUFA. No correlation was evident between n–3 PUFA induced change in RBC DHA or EPA levels and change in [11C]DTBZ BPND in striatal subdivisions. However, pre-supplementation RBC DHA levels was predictive of baseline performance (i.e., adjusted hit rate, AHR on 3-back) on the n-back task (y = 0.19+0.07, r2 = 0.55, p = 0.009). In addition, subjects AHR performance improved on 3-back post-supplementation (pre 0.65±0.27, post 0.80±0.15, p = 0.04). The correlation between n-back performance, and DHA levels are consistent with reports in which higher DHA levels is related to improved cognitive performance. However, the lack of change in [11C]DBTZ BPND indicates that striatal VMAT2 regulation is not the mechanism of action by which n–3 PUFA improves cognitive performance. 相似文献
6.
Eriocaulon raipurense (Eriocaulaceae) is described and illustrated as a new species from Madhya Pradesh, India. The species is closely allied to E. hamiltonianum but differs in the size and apex of involucral bancts, white-pilose nature of floral bracts and colour of female petals. 相似文献
7.
Michael Jae-Yoon Chung Abram L. Friesen Dieter Fox Andrew N. Meltzoff Rajesh P. N. Rao 《PloS one》2015,10(11)
A fundamental challenge in robotics today is building robots that can learn new skills by observing humans and imitating human actions. We propose a new Bayesian approach to robotic learning by imitation inspired by the developmental hypothesis that children use self-experience to bootstrap the process of intention recognition and goal-based imitation. Our approach allows an autonomous agent to: (i) learn probabilistic models of actions through self-discovery and experience, (ii) utilize these learned models for inferring the goals of human actions, and (iii) perform goal-based imitation for robotic learning and human-robot collaboration. Such an approach allows a robot to leverage its increasing repertoire of learned behaviors to interpret increasingly complex human actions and use the inferred goals for imitation, even when the robot has very different actuators from humans. We demonstrate our approach using two different scenarios: (i) a simulated robot that learns human-like gaze following behavior, and (ii) a robot that learns to imitate human actions in a tabletop organization task. In both cases, the agent learns a probabilistic model of its own actions, and uses this model for goal inference and goal-based imitation. We also show that the robotic agent can use its probabilistic model to seek human assistance when it recognizes that its inferred actions are too uncertain, risky, or impossible to perform, thereby opening the door to human-robot collaboration. 相似文献
8.
Bibek Yumnam Yadvendradev V. Jhala Qamar Qureshi Jesus E. Maldonado Rajesh Gopal Swati Saini Y. Srinivas Robert C. Fleischer 《PloS one》2014,9(11)
Even with global support for tiger (Panthera tigris) conservation their survival is threatened by poaching, habitat loss and isolation. Currently about 3,000 wild tigers persist in small fragmented populations within seven percent of their historic range. Identifying and securing habitat linkages that connect source populations for maintaining landscape-level gene flow is an important long-term conservation strategy for endangered carnivores. However, habitat corridors that link regional tiger populations are often lost to development projects due to lack of objective evidence on their importance. Here, we use individual based genetic analysis in combination with landscape permeability models to identify and prioritize movement corridors across seven tiger populations within the Central Indian Landscape. By using a panel of 11 microsatellites we identified 169 individual tigers from 587 scat and 17 tissue samples. We detected four genetic clusters within Central India with limited gene flow among three of them. Bayesian and likelihood analyses identified 17 tigers as having recent immigrant ancestry. Spatially explicit tiger occupancy obtained from extensive landscape-scale surveys across 76,913 km2 of forest habitat was found to be only 21,290 km2. After accounting for detection bias, the covariates that best explained tiger occupancy were large, remote, dense forest patches; large ungulate abundance, and low human footprint. We used tiger occupancy probability to parameterize habitat permeability for modeling habitat linkages using least-cost and circuit theory pathway analyses. Pairwise genetic differences (F
ST) between populations were better explained by modeled linkage costs (r>0.5, p<0.05) compared to Euclidean distances, which was in consonance with observed habitat fragmentation. The results of our study highlight that many corridors may still be functional as there is evidence of contemporary migration. Conservation efforts should provide legal status to corridors, use smart green infrastructure to mitigate development impacts, and restore habitats where connectivity has been lost. 相似文献
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10.
The concepts of feed pretreatment, phase separation, and whole-cell immobilization technology have been incorporated in this investigation for the development of rational and cost-effective two- and three-stage methane recovery systems from water hyacinth (WH)Analyses of laboratory data reveal that a three-stage system could be designed with an alkali pretreatment stage [3.6% Na(2)CO(3) + 2.5% Ca(OH)(2) W/W, 24 h HRT] followed by an open acid reactor (2.1 days HRT) and closed immobilized methane reactor (12 h HRT), providing steady-state COD conversion of 62-65%, TVA conversion of 91-95%, and gas productivity of 4.08-5.36 L/L reactor volume/day with 82% methane. A gas yield of 50 L/kg WH/day (dry wt basis) at 35-37 degrees C is possible with this system. Insulation bricks, with particle size distribution of 500-3000 mum, were used as support material in the reactors at organic loading rate of 20 kg COD/m(3) day. The reactors matured in 15-18 weeksSubstantial reduction in retention time for the conversion of volatile acids in immobilized methane reactors prompted further research on the combined immobilized reactor to make possible an additional reduction in the cost of a WH-based biogas system. Evaluation of laboratory data reveals that a two-stage system could be designed with an open alkali pretreatment stage and a combined immobilized reactor (12 h HRT), providing steady-state COD conversion of 53% and gas productivity of 3.1 L/L reactor volume/day with 86% methane. A gas yield of 44 L/kg WH/day (dry wt basis) at 35-37 degrees C could be obtained from this system. Insulation bricks, with 500-1000 mum particle size distribution, was used as support material at an organic loading rate of 15 kg COD/m(3) day. Notwithstanding the fact that the technology in this study has been developed with water hyacinth as substrate, the implicit principles could be extended to any other organic substrate. 相似文献