934 resultados para Approximate filtering


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The Mediterranean flour moth, Anagasta kuehniella, is one of the most important insect pests of grains, reported worldwide, feeding on stored grains and products of rice, rye, corn and wheat. Plants synthesize a variety of molecules, including trypsin inhibitors, to defend themselves against attack by insects. In this study, a trypsin inhibitor (PFTI) was purified from Plathymenia foliolosa (Benth.) seeds and was tested for insect growth regulatory effect. The survival and mass of A. kuehniella larvae feeding on control seeds were about 82.7% and 5 ring, respectively, whereas survival on seeds containing 0.7% PFTI was about 56%, while a 66.1% reduction in the average mass of the larvae was observed. The results from dietary utilization experiments with A. kuehniella larvae showed a reduction in efficiency of conversion of ingested food and digested food, and an increase in approximate digestibility and metabolic cost. The level of trypsin was significantly decreased in larval midgut and increased in the feces of larvae reared on a diet containing 0.7% PFTI. Results indicate that PFTI possesses a toxic effect against A. kuehniella larvae. (C) 2008 Elsevier Inc. All rights reserved.

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This study evaluates the impacts of Brazilian highway conditions on fuel consumption and, consequently, on carbon dioxide (COO emissions. For the purpose of this study, highway conditions refer to the level of highway maintenance: the incidence of large potholes, large surface cracks, uneven sections, and debris. Primary computer collected data related to the fuel consumption of three types of trucks were analyzed. The data were derived from 88 trips taken over six routes, each route representative of one of two highway conditions: better or worse. Study results are initially presented for each type of truck being monitored. The results are then aggregated to approximate the entire Brazilian highway network. In all cases, results confirmed environmental benefits resulting from travel over the better routes. There was found to be an increase in energy efficiency from traveling better roads, which resulted in lower fuel consumption and lower CO(2) emissions. Statistical analysis of the results suggests that, in general, fuel consumption data were significant at *P < 0.05, rejecting the null hypothesis that average fuel consumption from traveling the better routes is statistically equal to average fuel consumption from traveling the worse routes. Improved Brazilian road conditions would generate economic benefits, reduce dependency on and consumption of fossil fuels (due to the increase in energy efficiency), and reduce CO(2) emissions. These findings may have additional relevancy if Brazil needs to reduce carbon dioxide emissions to reach future Kyoto Protocol`s emissions targets, which should take effect in January 2013. (c) 2008 Elsevier B.V. All rights reserved.

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The development of genetic maps for auto-incompatible species, such as the yellow passion fruit (Passiflora edulis Sims f.flavicarpa Deg.) is restricted due to the unfeasibility of obtaining traditional mapping populations based on inbred lines. For this reason, yellow passion fruit linkage maps were generally constructed using a strategy known as two-way pseudo-testeross, based on monoparental dominant markers segregating in a 1:1 fashion. Due to the lack of information from these markers in one of the parents, two individual (parental) maps were obtained. However, integration of these maps is essential, and biparental markers can be used for such an operation. The objective of our study was to construct an integrated molecular map for a full-sib population of yellow passion fruit combining different loci configuration generated from amplified fragment length polymorphisms (AFLPs) and microsatellite markers and using a novel approach based on simultaneous maximum-likelihood estimation of linkage and linkage phases, specially designed for outcrossing species. Of the total number of loci, approximate to 76%, 21%, 0.7%, and 2.3% did segregate in 1:1, 3:1, 1:2:1, and 1:1:1:1 ratios, respectively. Ten linkage groups (LGs) were established with a logarithm of the odds (LOD) score >= 5.0 assuming a recombination fraction : <= 0.35. On average, 24 markers were assigned per LG, representing a total map length of 1687 cM, with a marker density of 6.9 cM. No markers were placed as accessories on the map as was done with previously constructed individual maps.

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Whole rice has been widely studied due to the abundance of bioactive compounds in its pericarp. Some of the beneficial effects of these compounds on human health have been attributed to their antioxidant and other biological activities, such as enzyme inhibition. In this work, we evaluated the contents of total, soluble and insoluble phenolic compounds of 6 red and 10 non-pigmented genotypes of whole rice as well as their inhibitory effect on the activity of angiotensin I-converting enzyme (ACE). The effects of cooking on phenolics and their inhibitory activities were also investigated. Red genotypes showed high content of phenolics, mainly soluble compounds, at an average of 409.7 mg ferulic acid eq./100 g, whereas overall lower average levels (99.4 mg ferulic acid eq./100 g) at an approximate soluble/insoluble compound ratio of 1:1 were observed in non-pigmented rice. Pigmented rice displayed a greater inhibitory effect on ACE than non-pigmented rice. In fact, a significant correlation between the content of soluble phenolics and ACE inhibition was observed (r = 0.8985, p < 0.05). In addition to significantly reducing the levels of total phenolics and ACE inhibition, cooking altered the soluble/insoluble compound ratio, especially among red rice genotypes. (C) 2011 Elsevier Ltd. All rights reserved.

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The aim of this research was to perform a stability testing of spray- and spouted bed-dried extracts of Passiflora alata Dryander (Passion flower) under stress storage conditions. Spouted bed- and spray-dried extracts were characterized by determination of the average particle diameter (dP), apparent moisture content (XP), total flavonoid content (TF), and vitexin content. Smaller and more irregular particles were generated by the spouted bed system due to a higher attrition rate (surface erosion) inside the dryer. The SB dryer resulted in an end product with higher concentration of flavonoids (approximate to 10%) and lower moisture content (1.6%, dry basis) than the spray dryer, even with both dryers working at similar inlet drying air temperature and ratio between the extract feed flow rate to drying air flow rate (Ws/Wg). Samples of the spouted bed- and spray-dried extracts were stored at two different temperatures (34 and 45 degrees C) and two different relative humidities (52 and 63% RH for 34 degrees C; 52 and 60% RH for 45 degrees C) in order to perform the stability testing. The dried extracts were stored for 28 days and were analyzed every 4 days. The flavonoid vitexin served as the marker compound, which was assayed during the storage period. Results revealed shelf lives ranging from 9 to 184 days, depending on the drying process and storage conditions.

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An exact analytical solution is obtained for the transient dissolution of solid spheres in a diffusion-controlled environment. This result provides a useful reference point for drug testing in humans. The dimensionless solution is expressed in terms of a single parameter, which accounts for solubility, bulk flow, and stagnant fluid composition. A simple, explicit and exact expression was found to predict time-to-complete dissolution (TCD). An approximate solution was also found which tracks the exact case for low solubility conditions.

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Extracting human postural information from video sequences has proved a difficult research question. The most successful approaches to date have been based on particle filtering, whereby the underlying probability distribution is approximated by a set of particles. The shape of the underlying observational probability distribution plays a significant role in determining the success, both accuracy and efficiency, of any visual tracker. In this paper we compare approaches used by other authors and present a cost path approach which is commonly used in image segmentation problems, however is currently not widely used in tracking applications.

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An approximate analytical technique employing a finite integral transform is developed to solve the reaction diffusion problem with Michaelis-Menten kinetics in a solid of general shape. A simple infinite series solution for the substrate concentration is obtained as a function of the Thiele modulus, modified Sherwood number, and Michaelis constant. An iteration scheme is developed to bring the approximate solution closer to the exact solution. Comparison with the known exact solutions for slab geometry (quadrature) and numerically exact solutions for spherical geometry (orthogonal collocation) shows excellent agreement for all values of the Thiele modulus and Michaelis constant.

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The area of private land suitable and available for growing hoop pine (Araucaria cunninghamii) on the Atherton Tablelands in North Queensland was modelled using a geographic information system (GIS). In Atherton, Eacham and Herberton shires, approximately 64,700 ha of privately owned land were identified as having a mean annual rainfall and soil type similar to Forestry Plantations Queensland (FPQ) hoop pine growth plots with an approximate growth rate of 20 m3 per annum. Land with slope of over 25° and land covered with native vegetation were excluded in the estimation. If land which is currently used for high-value agriculture is also excluded, the net area of land potentially suitable and available for expansion of hoop pine plantations is approximately 22,900 ha. Expert silvicultural advice emphasized the role of site preparation and weed control in affecting the long-term growth rate of hoop pine. Hence, sites with less than optimal fertility and rainfall may be considered as being potentially suitable for growing hoop pine at a lower growth rate. The datasets had been prepared at various scales and differing precision for their description of land attributes. Therefore, the results of this investigation have limited applicability for planning at the individual farm level but are useful at the regional level to target areas for plantation expansion.

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Heat transfer and entropy generation analysis of the thermally developing forced convection in a porous-saturated duct of rectangular cross-section, with walls maintained at a constant and uniform heat flux, is investigated based on the Brinkman flow model. The classical Galerkin method is used to obtain the fully developed velocity distribution. To solve the thermal energy equation, with the effects of viscous dissipation being included, the Extended Weighted Residuals Method (EWRM) is applied. The local (three dimensional) temperature field is solved by utilizing the Green’s function solution based on the EWRM where symbolic algebra is being used for convenience in presentation. Following the computation of the temperature field, expressions are presented for the local Nusselt number and the bulk temperature as a function of the dimensionless longitudinal coordinate, the aspect ratio, the Darcy number, the viscosity ratio, and the Brinkman number. With the velocity and temperature field being determined, the Second Law (of Thermodynamics) aspect of the problem is also investigated. Approximate closed form solutions are also presented for two limiting cases of MDa values. It is observed that decreasing the aspect ratio and MDa values increases the entropy generation rate.

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We describe a search for compact dwarf galaxies in the Fornax cluster using the FLAIR spectrograph on the UK Schmidt Telescope. We measured radial velocities of 453 compact galaxies brighter than B-T approximate to 17.3 and found seven new compact dwarf cluster members that were not classified in previous surveys as members of the cluster. These are amongst the most compact, high surface brightness dwarf galaxies known. The inclusion of these galaxies in the cluster does not change the total luminosity function significantly, but they are important because of their extreme nature; one in particular appears to be a dwarf spiral. Three of the new dwarfs have strong emission lines and we identify them as blue compact dwarfs (BCDs), doubling the number of confirmed BCDs in the cluster. We also determined that none of the compact dwarf elliptical (M32-like) candidates is in the cluster, down to an absolute magnitude M-B = -13.2. We have investigated the claim of Irwin et al. that there is no strong relation between surface brightness and magnitude for the cluster members and find some support for this for the brighter galaxies (B-T < 17.3), but fainter galaxies still need to be measured.

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In the adult male Sprague-Dawley rat, a species commonly used to study tolerance to the antinociceptive effects of morphine, approximate to 10% of the morphine dose is metabolized to normorphine-3-glucuronide (NM3G). In contrast, NM3G is a relatively minor metabolite of morphine in human urine reportedly accounting for approximate to 1% of the morphine dose. To date, the pharmacology of NM3G has been poorly characterized. Therefore, our studies were designed to determine whether the intrinsic pharmacology of NM3G is similar to that of morphine-3-glucuronide (M3G), the major metabolite of morphine, which has been shown to be a potent central nervous system (CNS) excitant and to attenuate the intrinsic antinociceptive effects of morphine in rats. The CNS excitatory potency of NM3G was found to be approximately half that of M3G, inducing convulsions in rats at intracerebroventricular (i.c.v.) doses of greater than or equal to 16.8 nmol. When administered before morphine (70 nmol i.c.v.), NM3G (8.9 nmol i.c.v.) attenuated antinociception for up to 2 hr, but when administered after morphine, no significant attenuation of morphine antinociception was observed. Thus, after i.c.v. administration, NM3G like M3G, is a potent CNS excitant and antianalgesic in the rat. NM3G may therefore play a role in the development of tolerance to the antinociceptive effects of morphine in the rat as has been proposed previously for M3G.

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Hydromorphone-3-glucuronide (H3G) was synthesized biochemically using rat liver microsomes, uridine-5'-diphosphoglucuronic acid (UDPGA) and the substrate, hydromorphone. Initially, the crude putative H3G product was purified by ethyl acetate precipitation and washing with acetonitrile, Final purification was achieved using semi-preparative high-performance-liquid-chromatography (HPLC) with ultraviolet (UV) detection. The purity of the final H3G product was shown by HPLC with electrochemical and ultraviolet detection to be > 99.9% and it was produced in a yield of approximate to 60% (on a molar basis). The chemical structure of the putative H3G was confirmed by enzymatic hydrolysis of the glucuronide moiety using P-glucuronidase, producing a hydrolysis product with the same HPLC retention time as the hydromorphone reference standard. Using HPLC with tandem mass spectrometry (HPLC-MS-MS) in the positive ionization mode, the molecular mass (M+1) was found to be 462 g/mol, in agreement with H3G's expected molecular weight of 461 g/mol. Importantly, proton-NMR indicated that the glucuronide moiety was attached at the 3-phenolic position of hydromorphone. A preliminary evaluation of H3G's intrinsic pharmacological effects revealed that following icy administration to adult male Sprague-Dawley rats in a dose of 5 mu g, H3G evoked a range of excitatory behavioural effects.including chewing, rearing, myoclonus, ataxia and tonic-clonic convulsions, in a manner similar to that reported previously for the glucuronide metabolites of morphine, morphine-3-glucuronide and normorphine-3-glucuronide.

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Strategies for sampling sediment bacteria were examined in intensive shrimp, Penaeus monodon (Fabricius), ponds in tropical Australia. Stratified sampling of bacteria at the end of the production season showed that the pond centre, containing flocculated sludge, had significantly higher bacterial counts (15.5 X 10(9) g(-1) dw) than the pond periphery (8.1 X 10(9) g(-1) dw), where the action of aerators had swept the pond floor. The variation in bacterial counts between these two zones within a pond was higher than that between sites within each zone or between ponds. Therefore, sampling effort should be focused within these zones: for example, sampling two ponds at six locations within each of the two zones resulted in a coefficient of variation of approximate to 5%. Bacterial numbers in the sediment were highly correlated with sediment grain size, probably because eroded soil particles and organic waste both accumulated in the centre of the pond. Despite high inputs of organic matter added to the ponds, principally as pelleted feeds, the mean bacterial numbers and nutrient concentrations (i.e. organic carbon, nitrogen and phosphorus) in the sediment were similar to those found in mangrove sediments. This suggests that bacteria are rapidly remineralizing particulates into soluble compounds. Bacterial numbers were highly correlated with organic carbon and total kjeldahl nitrogen in the sediment, suggesting that these were limiting factors to bacterial growth.

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The koala, Phascolarctos cinereus, is a geographically widespread species endemic to Australia, with three currently recognized subspecies: P.c. adustus, P.c. cinereus, and P.c. victor. Intraspecific variation in the mitochondrial DNA (mtDNA) control region was examined in over 200 animals from 16 representative populations throughout the species' range. Eighteen different haplotypes were defined in the approximate to 860 bp mtDNA control region as determined by heteroduplex analysis/temperature gradient gel electrophoresis (HDA/TGGE). Any single population typically possessed only one or two haplotypes yielding an average within-population haplotypic diversity of 0.180 +/- 0.003, and nucleotide diversity of 0.16%. Overall, mtDNA control region sequence diversity between populations averaged 0.67%, and ranged from 0% to 1.56%. Nucleotide divergence between populations averaged 0.51%, and ranged from 0% to 1.53%. Neighbour-joining methods revealed limited phylogenetic distinction between geographically distant populations of koalas, and tentative support for a single evolutionarily significant unit (ESU). This is consistent with previous suggestions that the morphological differences formalized by subspecific taxonomy may be interpreted as clinal variation. Significant differentiation in mtDNA-haplotype frequencies between localities suggested that little gene now currently exists among populations. When combined with microsatellite analysis, which has revealed substantial differentiation among koala populations, we conclude that the appropriate short-term management unit (MU) for koalas is the local population.