893 resultados para Pure points of a measure


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Comunicación a congreso (póster): 11th European Biological Inorganic Chemistry Conference EUROBIC 11. 12-16 September, 2012 - Granada (Spain)

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Entre os anos de 1942 e 1943, Werner Heisenberg produziu um manuscrito que resguarda as suas mais graves e amplas concepções filosóficas. Intitulado pelos editores como Ordenação da Realidade após a morte do autor, o escrito diagnostica uma profunda crise não somente na esfera da ciência, mas igualmente nos campos da moral e da política. O propósito desta tese é discutir as ideias apresentadas por Heisenberg, a partir da questão que compartilhamos com o físico sobre como o homem se orienta no mundo. A crise serve para demonstrar a necessidade de rearticulação da ontologia. Não se trata simplesmente de reconsiderar a divisão clássica entre objetividade e subjetividade, entre lei moral e sentimento, entre fundar a política na igualdade ou na liberdade. Tais dicotomias devem ser suspensas em prol de uma reconsideração sobre a determinação do ente a partir da totalidade de mundo, os processos de temporalização que conferem a medida das atividades humanas e as diferentes fontes que oferecem ao homem o poder de estabelecer comunidade. Reformular o conceito de realidade, bem como estabelecer a sua possibilidade de compreensão a partir de níveis e âmbitos, tal é o caminho da nossa confrontação com Heisenberg, a qual supera a trivialidade de um realismo como suposição de coisas simplesmente dadas.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The temporal variation of components of a moderately diverse (H=1.46) tropical estuarine fish assemblage (long. 146°30'E, lat. 8°45'S) was directed by salinities that had been determined by local oceanographic and probably topographic conditions. For this assemblage, two types of intrayear component profiles are predicted. Pooled data (1988-91) reveal a large component of regular/resident species (43%) in an assemblage which has been under a narrow temperature regime «5T). These results facilitate a discussion on the relevance and usefulness of three hypotheses often cited in studies concerning species diversity and component characteristics of the subtropical/tropical coastal nonreef fish assemblages. Manifestations of the assemblage are reflected in catch composition and weights of 39 trials conducted for a selective prawning gear whose performance in bycatch reduction, mainly for finfishes, is judged by an index, E, we have previously proposed. This gear is capable of harvesting the prawn while conserving the demersal fish. Behavioral responses to netting of the prawns and the finfishes, especially the nearshore surface schoolers such as leiognathids, are discussed from several points of view. An adaptation in terms of group selection for leiognathids of their locking mechanism of median fin spines has been interpreted. For the purpose of bycatch reduction or E enhancement, suggestions for improvements in net design and trawl configuration by considering the behavioral features of fish are made. Our original formula of E is modified for general use. Bycatch problems in the regional prawn fisheries and their possible impacts on fishery planning and development in Papua New Guinea as a developing country are discussed. The gear tested may offer enormous ecological and economic benefits. The gear is multipurpose, extremely simple, and can also be used as a biological sampler.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The California fishery for red sea urchins, Strongylocentrotus franciscanus, has undergone explosive growth in recent years and is approaching full exploitation. Thus, there is considerable interest in enhancing stocks to maintain a high rate of landings. Fishable stocks of red sea urchins in different areas appear to be limited at three stages in their life history: By the availability of larvae, by the survival of newly settled to mid-sized animals, and by the food available to support growth and reproduction of larger animals. Here I review other efforts, notably the extensive Japanese work, to enhance fishable stocks of benthic marine invertebrates, and consider the potential options for red sea urchins at different points of limitation. These include collecting or culturing seed for outplanting, physical habitat improvement measures, improving the food supply, and conservation measures to protect existing stocks until alternate methods are proven and in place. The options are compared in terms of biological feasibility, capital and labor requirements, and potential implications for change in the structure of the fishing industry.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The location of a flame front is often taken as the point of maximum OH gradient. Planar laser-induced fluorescence of OH can be used to obtain the flame front by extracting the points of maximum gradient. This operation is typically performed using an edge detection algorithm. The choice of operating parameters a priori poses significant problems of robustness when handling images with a range of signal-to-noise ratios. A statistical method of parameter selection originating in the image processing literature is detailed, and its merit for this application is demonstrated. A reduced search space method is proposed to decrease computational cost and render the technique viable for large data sets. This gives nearly identical output to the full method. These methods demonstrate substantial decreases in data rejection compared to the use of a priori parameters. These methods are viable for any application where maximum gradient contours must be accurately extracted from images of species or temperature, even at very low signal-to-noise ratios.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Colonies of the scleractinian coral Acropora palmata, listed as threatened under the US Endangered Species Act in 2006, have been monitored in Hawksnest Bay, within Virgin Islands National Park, St. John, from 2004 through 2010 by scientists with the US Geological Survey, National Park Service, and the University of the Virgin Islands. The focus has been on documenting the prevalence of disease, including white band, white pox (also called patchy necrosis and white patches), and unidentified diseases (Rogers et al., 2008; Muller et al., 2008). In an effort to learn more about the pathologies that might be involved with the diseases that were observed, samples were collected from apparently healthy and diseased colonies in July 2009 for analysis. Two different microbial assays were performed on Epicentre Biotechnologies DNA swabs containing A. palmata coral mucus, and on water and sediment samples collected in Hawksnest Bay. Both assays are based on polymerase chain reaction (PCR) amplification of portions of the small rRNA gene (16S). The objectives were to determine 1) if known coral bacterial pathogens Serratia marcescens (Acroporid Serratiosis), Vibrio coralliilyticus (temperature-dependent bleaching, White Syndrome), Vibrio shiloi (bleaching, necrosis), and Aurantimonas coralicida (White Plague Type II) were present in any samples, and 2) if there were any differences in microbial community profiles of each healthy, unaffected or diseased coral mucus swab. In addition to coral mucus, water and sediment samples were included to show ambient microbial populations. In the first test, PCR was used to separately amplify the unique and diagnostic region of the 16S rRNA gene for each of the coral pathogens being screened. Each pathogen test was designed so that an amplified DNA fragment could be seen only if the specific pathogen was present in a sample. A positive result was indicated by bands of DNA of the appropriate size on an agarose gel, which separates DNA fragments based on the size of the molecule. DNA from pure cultures of each of the pathogens was used as a positive control for each assay.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This paper outlines the development of the electron beam recrystallization approach to the formation of silicon-on-insulator layers. The technique of recrystallizing seeded layers by a line electron beam has been widely adopted. Present practice in electron beam recrystallization is reviewed, both from materials and process points of view. Applications of silicon-on-insulator substrates formed in this way are described, particularly in three-dimensional integration. © 1988.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The deteriorating condition of one of the most magnificent lakes of India, the Dal Lake, has provoked a lot of research interest from the biological and ecological points of view. However, the impact of deterioration of the ecology on the inhabitant fisher folk around Dal Lake has not been given much importance. In this study, the three major beats of the lake, namely, Hazratbal, Nishat and Nehru Park, were surveyed, randomly taking 10% of the fishermen families. It was observed that the summer mean catch per day (5.18 ± 0.69 kg) was more than the mean winter catch per day (2.85 ± 0.40 kg). However, the total annual catch per person was only 1195.56 ± 211.63 kg. Moreover, marketing through middlemen, especially, during summer, was observed to be very low fetching in terms of mean price per kilogram fish, amounting to Rs 37.50 ± 2.54 for local fish and Rs 22.50 ± 2.88 for the carp. It was also observed that the fisher folk had borrowed a good amount of money for the repair and construction of their houses and boats. Therefore, on the whole, the fishing business around Dal Lake was observed to be under severe stress. In this context, this paper has come out with recommendations to uplift the socio-economic conditions of the fishers.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

An experimental investigation of the unsteady interaction between a turbulent boundary layer and a normal shock wave of strength M∞ = 1.4 subject to periodic forcing in a parallel walled duct has been conducted. Emphasis has been placed on the mechanism by which changes in the global flow field influence the local interaction structure. Static pressure measurements and high speed Schlieren images of the unsteady interaction have been obtained. The pressure rise across the interaction and the appearance of the local SBLI structure have been observed to vary during the cycle of periodic shock wave motion. The magnitude of the pressure rise across the interaction is found to be related to the relative Mach number of the unsteady shock wave as it undergoes periodic motion. Variations in the upstream Influence of the interaction are sensitive to the magnitude and direction of shock wave velocity and acceleration and it is proposed that a viscous lag exists between the point of boundary layer separation and the shock wave position. Further work exploring the implications of these findings is proposed, including studies of the variation in position of the points of boundary layer separation and reattachment.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The study was conducted with the broad objectives to assess the existing situation of broodstock management and fish seed production in private fish seed farms in Bangladesh. The data were collected from 100 private hatcheries and 40 nurseries in seven upazilas under four districts. There was no shed in forty hatcheries and the owners faced many problems. Brood fish ponds were found suitable for rearing brood fish. About 66% of the hatchery owners collected brood fish from their own ponds and ponds of neighboring areas. Activities like pond preparation; manuring and supplementary feeding were done properly but stocking density of brood fish in 76% of the hatcheries was 3,000-7,000 kg/ha. Infection of argulosis was found in brood fish of 87% of the hatcheries. About 67% of the hatchery owners practiced inter-species crossing. Major problems faced by the hatchery owners were argulosis of brood fish, unavailability of pure brood stock, inadequate brood fish pond. The hatchery owners were found interested to find out the preventive measures of argulosis, develop pure brood stock of indigenous carp and import pure strain of exotic carp. According to the nursery operators, they cultivated hybrid fry because of high demand, rapid growth and good taste. Problems of using hatchery spawn as mentioned by the nursery operators were inbreeding, under sized and aged brood stock, stunted growth, physical deformities and high mortality of spawn due to unknown causes.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Any linearised theory of the initiation of friction-excited vibration via instability of the state of steady sliding requires information about the dynamic friction force in the form of a frequency response function for sliding friction. Recent measurements of this function for an interface consisting of a nylon pin against a glass disc are used to probe the underlying constitutive law. Results are compared to linearised predictions from the simplest ratestate model of friction, and a ratetemperature model. In both cases the observed variation with frequency is not compatible with the model predictions, although there are some significant points of similarity. The most striking result relates to variation of the normal load: any theory embodying the Coulomb relation F∝N would predict behaviour entirely at variance with the measurements, even though the steady friction force obtained during the same measurements does follow the Coulomb law. © 2011 Elsevier Ltd. All rights reserved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Pure cultures of Haliphthoros philippinensis, isolated from infected Penaeus monodon larvae, were exposed for 24 hours to varying concentrations of antifungal agents. The efficiency of each agent to inhibit sporulation and mycelial growth was measured. Effects on P. monodon eggs and larvae were also investigated. It is concluded that preliminary bioassay of larval tolerance to the suggested effective doses should always be made prior to prophylaxix or therapeutic applications.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This study describes the molecular identification of sixteen fish species present in processed products imported into Iran for human consumption. DNA barcoding using direct sequencing of about 650 bp of the mitochondrial Cytochrome Oxidase subunit I gene revealed incorrect labeling (31.25%). Substitution of fish species constitutes serious economic fraud, and our results increase concern regarding the trading of processed fish products in Iran from both health and conservation points of view.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Standard theories of decision-making involving delayed outcomes predict that people should defer a punishment, whilst advancing a reward. In some cases, such as pain, people seem to prefer to expedite punishment, implying that its anticipation carries a cost, often conceptualized as 'dread'. Despite empirical support for the existence of dread, whether and how it depends on prospective delay is unknown. Furthermore, it is unclear whether dread represents a stable component of value, or is modulated by biases such as framing effects. Here, we examine choices made between different numbers of painful shocks to be delivered faithfully at different time points up to 15 minutes in the future, as well as choices between hypothetical painful dental appointments at time points of up to approximately eight months in the future, to test alternative models for how future pain is disvalued. We show that future pain initially becomes increasingly aversive with increasing delay, but does so at a decreasing rate. This is consistent with a value model in which moment-by-moment dread increases up to the time of expected pain, such that dread becomes equivalent to the discounted expectation of pain. For a minority of individuals pain has maximum negative value at intermediate delay, suggesting that the dread function may itself be prospectively discounted in time. Framing an outcome as relief reduces the overall preference to expedite pain, which can be parameterized by reducing the rate of the dread-discounting function. Our data support an account of disvaluation for primary punishments such as pain, which differs fundamentally from existing models applied to financial punishments, in which dread exerts a powerful but time-dependent influence over choice.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The spring-summer successions of phytoplankton and crustacean zooplankton were examined weekly in Meiliang Bay of the subtropical Lake Taihu in 2004 and 2005. During the study period, the ecosystem of Meiliang Bay was characterized by (i) clearly declined nitrogen compounds (nitrate, TN, and ammonium) and slowly increased phosphorus compounds (TP and SRP), (ii) increased total phytoplankton density and rapid replacement of chlorophyta (mainly Ulothrix) by cyanobacteria (mainly Microcystis), and (iii) rapid replacement of large-sized crustaceans (Daphnia and Moina) by small-sized ones (Bosmina, Limnoithona, and Ceriodaphnia). Results from the CCA and correlation analysis indicate that the spring-summer phytoplankton succession was primarily controlled by abiotic factors. Cyanobacteria were mainly promoted by increased temperature and decreased concentrations of nitrogen compounds. The pure contribution of crustacean was low for the variation of phytoplankton suggesting a weak top-down control by crustacean zooplankton in the subtropical Lake Taihu.