1000 resultados para semi-Riemannian manifolds


Relevância:

20.00% 20.00%

Publicador:

Resumo:

One hundred and twenty crossbred pigs (Large White x Landrace) weaned at an average age of 28 days, were used. Pigs were alloted to five dietary treatments according to weight, sex and litter as follows: T1- Simple diet (SD) during whole Starter phase (SP) (28-63 days); T2- Semi-complex diet (SCD) for the first seven days followed by a SD during 28 days of SP; T3- SCD for the first 14 days followed by SD during 21 days of SP; T4- SCD for the first 21 days followed by SD during 14 days of SP; T5- SCD during the entire SP. A completely randomized block design was used with six replications. At the end of the SP one castrated male and one female, weighing closest to the average live weight of the group, were transferred to growing-finishing pens and fed growing-finishing diets ad libitum until they reached approximately 90kg live weight. Increasing the period of feeding the semi-complex diet resulted in a linear increase in average daily feed intake and average daily gain during the first 28 days of the initial phase. However, when the entire initial phase was considered there was a linear increase only in daily feed intake. There were no differences in incidence and severity of diarrhea in SP or in the performance of pigs during the growing-finishing phases. There were was no differences in average daily gain among diets from weaning to 90 kg body weight. It was concluded that the advantage of the semi-complex starter diet tended to disappear as age increased.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Four 0.02-ha earthen ponds at the UNESP Aquaculture Center, Jaboticabal, São Paulo, Brazil, were stocked with newly metamorphosed Macrobrachium rosenbergii post-larvae at 1.5 animals/m2. After 8 mo, prawn density at harvest ranged from 0.3/ m2 to 0.8/m2. Growth curves were determined for each population using von Bertalanffy growth functions. Asymptotic maximum length and asymptotic maximum weight increased as final population size decreased indicating that a strong density effect on prawn growth occurs in semi-intensive culture, even when populational density varies within a small range of less than 1 animal/m2.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A comparative study between the metric and the teleparallel descriptions of gravitation is made for the case of a scalar field. In contrast to the current belief that only spin matter could detect the teleparallel geometry, scalar matter being able to feel the metric geometry only, we show that a scalar field is able not only to feel anyone of these geometries, but also to produce torsion. Furthermore, both descriptions are found to be completely equivalent, which means that in fact, besides coupling to curvature, a scalar field couples also to torsion.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Numerous natural compounds have a potential for therapeutic applications, but may have to be chemically modified to alter toxic side effects. We investigated structural parameters that could affect the cytotoxicity of isocoumarins similar to 9,10-dihydroxy-5,7-dimethoxy-1H-naphtho(2,3c)pyran-1-one (paepalantine 1). Paepalantine 1 has antimicrobial activity, as well as significant in vitro cytotoxic effects in the McCoy cell line. Two other natural and two semi-synthetic isocoumarins with similar structures obtained from the capitula of Paepalanthus bromelioides were tested on the same cell line by the neutral red assay. Substitution of the 9 and/or 10-OH group made these compounds less cytotoxic.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this work are presented the values found with the experimental testing, in the semi-elliptic leaf spring, utilizing 24 strain gages, distributed in five leaves of springs; these values have been compared to the calculated values found with the application of Norm SAE J788 (1982). The results showed discrepancy between the values measured and calculated and that the Norm is not indicated to determine the actuating stress in any point of any leaf of the leaf spring, but due to its simplicity and quickness of the process it presents good precision for the pre-development of the product. Copyright © 2002 Society of Automotive Engineers, Inc.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We present the exact construction of Riemannian (or stringy) instantons, which are classical solutions of 2D Yang-Mills theories that interpolate between initial and final string configurations. They satisfy the Hitchin equations with special boundary conditions. For the case of U(2) gauge group those equations can be written as the sinh-Gordon equation with a delta-function source. Using the techniques of integrable theories based on the zero curvature conditions, we show that the solution is a condensate of an infinite number of one-solitons with the same topological charge and with all possible rapidities.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Semi-automatic building detection and extraction is a topic of growing interest due to its potential application in such areas as cadastral information systems, cartographic revision, and GIS. One of the existing strategies for building extraction is to use a digital surface model (DSM) represented by a cloud of known points on a visible surface, and comprising features such as trees or buildings. Conventional surface modeling using stereo-matching techniques has its drawbacks, the most obvious being the effect of building height on perspective, shadows, and occlusions. The laser scanner, a recently developed technological tool, can collect accurate DSMs with high spatial frequency. This paper presents a methodology for semi-automatic modeling of buildings which combines a region-growing algorithm with line-detection methods applied over the DSM.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A hundred and ninety-five (195) strains of Enterobacter spp., isolated from diverse clinical specimens - urine, feces, cateter, blood, wound, tracheal aspirate, vaginal fluid - were submitted to the conventional identification by biochemical tests, and were also submitted to the identification by panels NegCombo 20 of the system automated MicroScan - AutoScan- 4 (Dade Behring Inc., West Sacramento, CA, USA). The samples were from patients of the Clinical Laboratory from the School of Pharmacy and Biochemistry of UNOESTE, Presidente Prudente, SP, and from patients hospitalized at the University Hospital Domingos Leonardo Cerávolo, UNOESTE. Of the total of strains tested, 191 (97.9%) presented agreement between the two approaches utilized and 4 strains (2.1%) presented identification disagreement, that is, the genus identified was different in each approach. By this study, the conclusion is that both the approaches utilized for the identification presented advantages and disadvantages related to the cost, facility of execution, quickness, reliability and some other characteristics. Even so, our results showed that conventional methods represent a reliable tool for Enterobacter identification.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The purpose of this paper is to introduce a methodology for semi-automatic road extraction from aerial digital image pairs by using dynamic programming and epipolar geometry. The method uses both images from where each road feature pair is extracted. The operator identifies the corresponding road featuresand s/he selects sparse seed points along them. After all road pairs have been extracted, epipolar geometry is applied to determine the automatic point-to-point correspondence between each correspondent feature. Finally, each correspondent road pair is georeferenced by photogrammetric intersection. Experiments were made with rural aerial images. The results led to the conclusion that the methodology is robust and efficient, even in the presence of shadows of trees and buildings or other irregularities.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this paper is proposed a methodology for semiautomatic CBERS image orientation using roads as ground control. It is based on an iterative strategy involving three steps. In the first step, an operator identifies on the image the ground control roads and supplies along them a few seed points, which could be sparsely and coarsely distributed. These seed points are used by the dynamic programming algorithm for extracting the ground control roads from the image. In the second step, it is established the correspondences between points describing the ground control roads and the corresponding ones extracted from the image. In the last step, the corresponding points are used to orient the CBERS image by using the DLT (Direct Linear Transformation). The two last steps are iterated until the convergence of the orientation process is verified. Experimental results showed that the proposed methodology was efficient with several test images. In all cases the orientation process converged. Moreover, the estimated orientation parameters allowed the registration of check roads with pixel accuracy or better.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The biology and productivity of Myschocytarus drewseni were studied in semi urban conditions at Rio Claro, S P - Brazil. We observed 51 nest foundations, of which 24 (47%) were destroyed or predated, 13 (25.5 %) were abandoned and 14 (27.5%) completed the cycle. The life-span of colonies ranged from 44-427 days with a mean of 216.7 ± 140.6 days, producing 8-390 cells with a mean of 125.7 ± 137.9 cells, and 2-303 adults with a mean of 89.4 ± 110.36 adults. We observed a maximum of 3 utilizations/cell. This showed that the species presents asynchronous foundation and abandoningoccurs throughout the year. Also, the chance of a colony utilizing the same cells two or three times for adult production is highly dependent on the colony size/age, and the relation between them is positive, meaning that there is a greater chance of cell re-utilization in larger/older colonies.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This study shows the helminthic fauna of 16 rock cavies (Kerodon rupestris) from the semi-arid region in the State of Rio Grande do Norte, Brazil. Nine animals were captured from the wild and seven from a captive population located at the Centro de Multiplicação de Animais Silvestres, city of Mossoró, were examined in this study. The animals were slaughtered, and post mortem analysis of the digestive tract, trachea, heart, lungs, liver, pancreas, and kidneys were done in search for the presence of parasites. Five species of nematode (Paraspidodera uncinata, Trichostrongylus colubriformis, Trichuris gracilis, Trichuris muris, and Vianella lenti) and one species of cestode (Thysanotaenia congolensis) were identified.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The cotton disease known as angular leaf spot, caused by Xanthomonas axonopodis pv. malvacearum (Xam) has been causing cotton losses in several producing regions around the world. Xam is transmitted by seeds, which may be infected both externally and internally. Infected seeds constitute the main long-distance dissemination mode of the pathogen. In view of this, the use of healthy seeds is a must. To accomplish that, detection methodologies for the bacteria must be developed be used in seed health analysis laboratories. This study aimed to develop a semi-selective medium for Xam detection in cotton seeds. The semi-selective culture medium was named MSSXAN and it was consisted of peptone (5.0 g), beef extract (3 g), sucrose (5 g), soluble starch (10 g), agar (15 g), CaCl 2 (0.25 g), Tween 80 (10 mL), distilled water (1,000 mL), crystal violet solution at 1% (150 μL), cephalexin (50 mg 1*), methyl thyophanate (10 mg*) and chlorothalonil (10 mg*) - *added after culture medium autoclaving. This MSSXAN medium shows low repressiveness to Xam and it be used for isolation of this bacteria in cotton seeds health analysis. © 2009 Academic Journals Inc.