Two samples were taken and a total of 516 bacterial isolates were classified into groups using their whole-cell protein patterns. The distribution of bacteria into protein-pattern groups differed significantly between the two samples, suggesting variation in culturable bacterial flora.
Partial 16S rRNA gene sequences were determined for representatives of the commonest protein-pattern groups. Most of the sequences obtained were previously unknown, but relatively closely related to known sequences of organisms belonging to the α, β or γ subclasses of the proteobacteria, the first two subclasses being predominant. This classification of bacteria isolated on a diluted nutrient-rich medium… differed from recent culture-dependent studies using nutrient-rich media.
The uncultivated bacterial community was studied by analyzing ten partial 16S rRNA gene sequences cloned directly from activated sludge. None of the cloned sequences was identical to those determined for culturable organisms; or to those in the GenBank database. They were, however, related to the α or β subclasses of the proteobacteria, or to the gram-positive bacteria with a high G+C DNA content.
Different optimization techniques and rounding schemes were explored. The implementation results achieved better performance with lower resource usage than prior art. The 16-bit 1024-point FFT with the R22SDF architecture had a maximum clock frequency of 95.2 MHz and used 2802 slices on the Spartan-3, a throughput per area ratio of 0.034 Msamples/s/slice. The R4SDC architecture ran at 123.8 MHz and used 4409 slices on the Spartan-3, a throughput per area ratio of 0.028 Msamples/s/slice.
On Virtex-4, the 16-bit 1024-point R22SDF architecture ran at 235.6 MHz and used 2256 slice, giving a 0.104 Msamples/s/slice ratio; the 16-bit 1024-point… R4SDC architecture ran at 219.2 MHz and used 3064 slices, giving a 0.072 Msamples/s/slice ratio.
The R22SDF was more efficient than the R4SDC in terms of throughput per area due to a simpler controller and an easier balanced rounding scheme. This paper also shows that balanced stage rounding is an appropriate rounding scheme for pipeline FFT processors.
Here we address changes in seed bank density and its life history trait composition in century-old pastures, where contrasting reindeer densities have developed during the last decades. We cover the actual scales used by these wide-roaming herbivores by sampling 70 productive tundra habitats over 7,421 km 2 in the reindeer summer pastures of Northern Norway.
Results showed that the seed bank density was significantly lowered where reindeer densities had increased in recent decades, whereas the century-long history of grazing probably explains the main seed bank traits typical of grazing tolerant plants.
The dominant trait characteristics were small seeds (… dispersal mechanism and individuals with a graminoid growth form. Finally, differences between regions introduced trait variation independent of grazing history, reinforcing the importance of using scales covering several contexts when designing ecological studies.
Regenerator is one of the most crucial components to pulse tube cooler (PTC) and thermoacoustic engine. As such regenerator is scaled up to high-power, the thermal and hydrodynamic communication transverse to the acoustic axis gets weaker and weaker. Under this condition, any unsymmetric factor could cause serious instability to the cooler or engine, which degrades their performance. Investigation has been carried out on a high-power two-stage thermal-coupled U-shape Stirling-type PTC.
By detailed circumferential temperature measurements along the middle heat exchanger and second stage regenerator, a kind of temperature inhomogeneity caused by unsymmetric pre-cooling effect of inter-stage thermal bridge was found in the lower part of the regenerator of the PTC. The temperature… inhomogeneity originating from the middle heat exchanger of the second stage regenerator amplified itself in the lower part of the regenerator and then internal streaming formed. The maximal radial temperature difference could reach 30–40 K.
Experimental results show that the temperature inhomogeneity intensifies with increased pre-cooling power and its direction can be reversed by changing the pre-cooling effect of the first stage PTC to heating effect by using external thermal load. This research shows that it is important to maintain the heating or cooling effects of heat exchangers uniform in high-power regenerative coolers and engines.
The production of recombinant proteins is frequently enhanced at the levels of transcription, codon usage, protein folding and secretion. Overproduction of heterologous proteins, however, also directly affects the primary metabolism of the producing cells. By incorporation of the production of a heterologous protein into a genome scale metabolic model of the yeast Pichia pastoris , the effects of overproduction were simulated and gene targets for deletion or overexpression for enhanced productivity were predicted.
Overexpression targets were localized in the pentose phosphate pathway and the TCA cycle, while knockout targets were found in several branch points of glycolysis. Five out of 9 tested targets led to an enhanced production of cytosolic human superoxide dismutase (hSOD)…. Expression of bacterial β-glucuronidase could be enhanced as well by most of the same genetic modifications. Beneficial mutations were mainly related to reduction of the NADP/H pool and the deletion of fermentative pathways. Overexpression of the hSOD gene itself had a strong impact on intracellular fluxes, most of which changed in the same direction as predicted by the model.
In vivo fluxes changed in the same direction as predicted to improve hSOD production. Genome scale metabolic modeling is shown to predict overexpression and deletion mutants which enhance recombinant protein production with high accuracy.
The sociology oftourism can be considered applied sociology. Therefore, it is necessary toascertain the up skills of the sociologist in the process of tourism planning.The present paper refers to the idea of philosophic practitioner as atheoretical model and considers the sociologist as a facilitator of localtourism development.
To this purpose, I discuss some topics and working toolsthat can be used when the sociologist is asked to help local stakeholderscreate significant involvement of the local community. In particular, I proposesome self-assessment tools to be included in a tourism process centred on localparticipation. The paper focuses on fundamental questions concerning thetechniques of bottom up regulation and the techniques to facilitate the passagefrom individualism to… collaborative marketing in order to attract visitorssuitable to the destination.
The discussions are based inductively on tourismeconomic policies initiated inItalyto create collaboration between local institutions and enterprises aimed atintegrating local resources (accommodation structures, transport, gastronomy,art and archaeology, etc.) and creating districts or systems of Made inItalyhospitality. The results indicate the sociologist of tourism as a facilitatorof the collaborative partnership in support of the destination management. Manydifficulties in creating tourism districts or systems are due to the absence ofthis type of professional figure.
Laminar flame speeds of propane/air mixtures were determined experimentally over an extensive range of equivalence ratios at room temperature, 500 K, 650 K, and atmospheric pressure. Nitrogen addition to simulate effects of exhaust gas dilution on the laminar flame speed was also studied at these conditions for selected equivalence ratios.
The experiments employed the stagnation jet-wall flame configuration in which the flow velocity was obtained by using particle image velocimetry. The laminar flame speed was obtained using linear extrapolation to zero stretch rate. The measured flame speeds were compared with literature data and numerical predictions using a published detailed kinetic model (Qin, Z., Lissianski, V., Yang, H., Gardiner, W. C., Jr., Davis, S. G., and Wang, H., Proc…. Combust. Inst., vol. 28, pp. 1663-1669, 2000). The predictions generally agree well with the experimental data.
Both the data and model predictions reveal a quasi-linear relationship between the laminar flame speed and the dilution ratio, contrary to the nonlinear correlations commonly suggested in the literature. The linear dependence issue is numerically extended to include hydrogen and methane flame systems.
The simultaneous increase of atmospheric CO(2) and nitrogen (N) deposition to terrestrial ecosystems is predicted to alter plant productivity and, consequently, to change the amount and quality of above- and belowground carbon entering forest soils.
It is not known how such changes will impact the composition and function of soil fungal communities that play a key role in degrading complex carbon. We sequenced the fungal cellobiohydrolase I gene (cbhI) from soil DNA and cDNA to compare the richness and composition of resident and expressed cbhI genes at a U.S. Department of Energy free air-carbon dioxide enrichment (FACE) site (NC), which had been exposed to elevated atmospheric CO(2) and/or N fertilization treatment for several years.
Our results provide evidence that the richness and… composition of the cellulolytic fungi surveyed in this study were distinct in the DNA- and cDNA-based gene surveys and were dominated by Basidiomycota that have low or no representation in public databases. The surveys did not detect differences in richness or phylum-level composition of cbhI-containing, cellulolytic fungi that correlated with elevated CO(2) or N fertilization at the time of sampling.
The response of oilseed rape cultivars to infection with Agrobacterium tumefaciens and A. rhizogenes and the possibility of regenerating genetically transformed oilseed rape plants were examined. The frequency at which Agrobacterium induced galls or hairy-roots on in vitro cultured plants ranged from 10% to 70%, depending on the cultivar.
From galls induced by the tumorigenic strain T37, known to be strongly shoot inducing on tobacco, roots developed frequently. Occasionally, shoots formed and some of these produced tumour cell specific nopaline. Attempts to grow the transformed shoots into plants have so far been unsuccessful.
Whole plants transformed with Ri-T-DNA, however, were regenerated. These had crinkled leaves and abundant, frequently branching roots that showed reduced… geotropism, similar to previously isolated Ri T-DNA transformed tobacco and potato plants. The transformed oilseed rape plants flowered, but failed to form seeds.
The reliability analysis of critical systems is often performed using fault-tree analysis. Fault trees are analyzed using analytic approaches or Monte Carlo simulation. The usage of the analytic approaches is limited in few models and certain kinds of distributions. In contrast to the analytic approaches, Monte Carlo simulation can be broadly used. However, Monte Carlo simulation is time-consuming because of the intensive computations.
This is because an extremely large number of simulated samples may be needed to estimate the reliability parameters at a high level of confidence. In this paper, a tree model, called Time-to-Failure tree, has been presented, which can be used to accelerate the Monte Carlo simulation of fault trees. The time-to-failure tree of a system shows the relationship… between the time to failure of the system and the times to failures of its components.
Static and dynamic fault trees can be easily transformed into time-to-failure trees. Each time-to-failure tree can be implemented as a pipelined digital circuit, which can be synthesized to a field programmable gate array (FPGA). In this way, Monte Carlo simulation can be significantly accelerated. The performance analysis of the method shows that the speed-up grows with the size of the fault trees. Experimental results for some benchmark fault trees show that this method can be about 471 times faster than software-based Monte Carlo simulation.