991 resultados para Number line
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"21 July 1979."
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The present research was conducted to estimate the genetic trends for meat quality traits in a male broiler line. The traits analyzed were initial pH, pH at 6 h after slaughter, final pH, initial range of falling pH, final range of falling pH, lightness, redness, yellowness, weep loss, drip loss, shrink loss, and shear force. The number of observations varied between 618 and 2125 for each trait. Genetic values were obtained by restricted maximum likelihood, and the numerator relationship matrix had 107,154 animals. The genetic trends were estimated by regression of the broiler average genetic values with respect to unit of time (generations), and the average genetic trend was estimated by regression coefficients. Generally, for the traits analyzed, small genetic trends were obtained, except for drip loss and shear force, which were higher. The small magnitude of the trends found could be a consequence of the absence of selection for meat quality traits in the line analyzed. The estimates of genetic trends obtained were an indication of an improvement in the meat quality traits in the line analyzed, except for drip loss.
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Simulated annealing (SA) is an optimization technique that can process cost functions with degrees of nonlinearities, discontinuities and stochasticity. It can process arbitrary boundary conditions and constraints imposed on these cost functions. The SA technique is applied to the problem of robot path planning. Three situations are considered here: the path is represented as a polyline; as a Bezier curve; and as a spline interpolated curve. In the proposed SA algorithm, the sensitivity of each continuous parameter is evaluated at each iteration increasing the number of accepted solutions. The sensitivity of each parameter is associated to its probability distribution in the definition of the next candidate. (C) 2010 Elsevier Ltd. All rights reserved.
Diagnostic errors and repetitive sequential classifications in on-line process control by attributes
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The procedure of on-line process control by attributes, known as Taguchi`s on-line process control, consists of inspecting the mth item (a single item) at every m produced items and deciding, at each inspection, whether the fraction of conforming items was reduced or not. If the inspected item is nonconforming, the production is stopped for adjustment. As the inspection system can be subject to diagnosis errors, one develops a probabilistic model that classifies repeatedly the examined item until a conforming or b non-conforming classification is observed. The first event that occurs (a conforming classifications or b non-conforming classifications) determines the final classification of the examined item. Proprieties of an ergodic Markov chain were used to get the expression of average cost of the system of control, which can be optimized by three parameters: the sampling interval of the inspections (m); the number of repeated conforming classifications (a); and the number of repeated non-conforming classifications (b). The optimum design is compared with two alternative approaches: the first one consists of a simple preventive policy. The production system is adjusted at every n produced items (no inspection is performed). The second classifies the examined item repeatedly r (fixed) times and considers it conforming if most classification results are conforming. Results indicate that the current proposal performs better than the procedure that fixes the number of repeated classifications and classifies the examined item as conforming if most classifications were conforming. On the other hand, the preventive policy can be averagely the most economical alternative rather than those ones that require inspection depending on the degree of errors and costs. A numerical example illustrates the proposed procedure. (C) 2009 Elsevier B. V. All rights reserved.
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Wolbachia are intracellular microorganisms that form maternally-inherited infections within numerous arthropod species. These bacteria have drawn much attention, due in part to the reproductive alterations that they induce in their hosts including cytoplasmic incompatibility (CI), feminization and parthenogenesis. Although Wolbachia's presence within insect reproductive tissues has been well described, relatively few studies have examined the extent to which Wolbachia infects other tissues. We have examined Wolbachia tissue tropism in a number of representative insect hosts by western blot, dot blot hybridization and diagnostic PCR. Results from these studies indicate that Wolbachia are much more widely distributed in host tissues than previously appreciated. Furthermore, the distribution of Wolbachia in somatic tissues varied between different Wolbachia/host associations. Some associations showed Wolbachia disseminated throughout most tissues while others appeared to be much more restricted, being predominantly limited to the reproductive tissues. We discuss the relevance of these infection patterns to the evolution of Wolbachia/host symbioses and to potential applied uses of Wolbachia.
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A parametric study is carried out to investigate how geological inhomogeneity affects the pore-fluid convective flow field, the temperature distribution, and the mass concentration distribution in a fluid-saturated porous medium. The related numerical results have demonstrated that (1) the effects of both medium permeability inhomogeneity and medium thermal conductivity inhomogeneity are significant on the pore-fluid convective flow and the species concentration distribution in the porous medium; (2) the effect of medium thermal conductivity inhomogeneity is dramatic on the temperature distribution in the porous medium, but the effect of medium permeability inhomogeneity on the temperature distribution may be considerable, depending on the Rayleigh number involved in the analysis; (3) if the coupling effect between pore-fluid flow and mass transport is weak, the effect of the Lewis number is negligible on the pore-fluid convective flow and temperature distribution, hut it is significant on the species concentration distribution in the medium.
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We describe a sample of 13 bright (18.5 < B-J < 20.1), compact galaxies at low redshift (0.05 < z < 0.21) behind the Fornax Cluster. These galaxies are unresolved on UK Schmidt sky survey plates, and so they would be missing from most galaxy catalogs compiled from this material. The objects were found during initial observations of The Fornax Spectroscopic Survey. This project is using the Two-degree Field spectrograph on the Anglo-Australian Telescope to obtain spectra for a complete sample of all 14,000 objects, stellar and nonstellar, with 16.5 < B-J < 19.7, in a 12 deg(2) area centered on the Fornax Cluster of galaxies. The surface density of compact galaxies with magnitudes 16.5 < B-J < 19.7 is 7 +/- 3 deg(-2), representing 2.8% +/- 1.6% of all local (z < 0.2) galaxies to this limit. There are 12 +/- 3 deg(-2) with 16.5 < B-J < 20.2. They are luminous (-21.5 < M-B < -18.0, for H-o = 50 km s(-1) Mpc(-1)), and most have strong emission lines (H alpha equivalent widths of 40-200 Angstrom) and small sizes typical of luminous H II galaxies and compact narrow emission line galaxies. Four out of 13 have red colors and early-type spectra, and so they are unlikely to have been detected in any previous surveys.
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A proteomics approach was used to identify the proteins potentially implicated in the cellular response concomitant with elevated production levels of human growth hormone in a recombinant Chinese hamster ovary (CHO) cell line following exposure to 0.5 mM butyrate and 80 muM zinc sulphate in the production media. This involved incorporation of two-dimensional (2-D) gel electrophoresis and protein identification by a combination of N-terminal sequencing, matrix-assisted laser desorption/ionisation-time of flight mass spectrometry, amino acid analysis and cross species database matching. From these identifications a CHO 2-D reference,map and annotated database have been established. Metabolic labelling and subsequent autoradiography showed the induction of a number of cellular proteins in response to the media additives butyrate and zinc sulphate. These were identified as GRP75, enolase and thioredoxin. The chaperone proteins GRP78, HSP90, GRP94 and HSP70 were not up-regulated under these conditions.
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The suspension Chinese Hamster Ovary cell line, 13-10-302, utilizing the metallothionein (MT) expression system producing recombinant human growth hormone (hGH) was studied in a serum-free and cadmium-free medium at different fermentation scales and modes of operation. Initial experiments were carried out to optimize the concentration of metal addition to induce the MT promoter. Subsequently, the cultivation of the 13-10-302 cell line was scaled up from spinner flasks into bioreactors, and the cultivation duration was extended with fed-batch and perfusion strategies utilizing 180 muM zinc to induce the promoter controlling expression of recombinant hGH. It was shown that a fed-batch process could increase the maximum cell numbers twofold, from 3.3 to 6.3 x 10(6) cell/mL, over those obtained in normal batch fermentations, and this coupled with extended fermentation times resulted in a fourfold increase in final hGH titer, from 135 +/- 15 to 670 +/- 70 mg/L at a specific productivity q(hGH) value of 12 pg cell(-1)d(-1). The addition of sodium butyrate increased the specific productivity of hGH in cells to a value of approximately 48 pg cell(-1)d(-1), resulting in a final hGH titer of over a gram per liter during fed-batch runs. A BioSep acoustic cell recycler was used to retain the cells in the bioreactor during perfusion operation. It was necessary to maintain the specific feeding rates (SFR) above a value of 0.2 vvd/(10(6) cell/mL) to maintain the viability and productivity of the 13-10-302 cells; under these conditions the viable cell number increased to over 107 cell/mL and resulted in a volumetric productivity of over 120 mg(hGH) L(-1)d(-1). Process development described in this work demonstrates cultivation at various scales and sustained high levels of productivity under cadmium free condition in a CHO cell line utilizing an inducible metallothionein expression system. (C) 2004 Wiley Periodicals, Inc.
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Purpose: The aversive nature of regenerative milieu is the main problem related to the failure of neuronal restoration in the injured spinal cord which however might be addressed with an adequate repair intervention. We evaluated whether glial cell line-derived neurotrophic factor (GDNF) may increase the ability of sciatic nerve graft, placed in a gap promoted by complete transections of the spinal cord, to enhance motor recovery and local fiber growth. Methods: Rats received a 4 mm-long gap at low thoracic level and were repaired with a fragment of the sciatic nerve. GDNF was added (NERVE+GDNF) or not to the grafts (NERVE-GDNF). Motor behavior score (BBB) and sensorimotor tests-linked to the combined behavior score (CBS), which indicate the degree of the motor improvement and the percentage of functional deficit, respectively, and also the spontaneous motor behavior in an open field by means of an infrared motion sensor activity monitor were analyzed. At the end of the third month post surgery, the tissue composed by the graft and the adjacent regions of the spinal cord was removed and submitted to the immunohistochemistry of the neurofilament-200 (NF-200), growth associated protein-43 (GAP-43), microtubule associated protein-2 (MAP-2), 5-hidroxytryptamine (serotonin, 5-HT) and calcitonin gene related peptide (CGRP). The immunoreactive fibers were quantified at the epicenter of the graft by means of stereological procedures. Results: Higher BBB and lower CBS levels (p < 0.001) were found in NERVE+GDNF rats. GDNF added to the graft increased the levels of individual sensorimotor tests mainly at the third month. Analysis of the spontaneous motor behavior showed decreases in the time and number of small movement events by the third month without changes in time and number of large movement events in the NERVE+GDNF rats. Immunoreactive fibers were encountered inside the grafts and higher amounts of NF-200, GAP-43 and MAP-2 fibers were found in the epicenter of the graft when GDNF was added. A small amount of descending 5-HT fibers was seen reentering in the adjacent caudal levels of the spinal cords which were grafted in the presence of GDNF, event that has not occurred without the neurotrophic factor. GDNF in the graft also led to a large amount of MAP-2 perikarya and fibers in the caudal levels of the cord gray matter, as determined by the microdensitometric image analysis. Conclusions: GDNF added to the nerve graft favored the motor recovery, local neuronal fiber growth and neuroplasticity in the adjacent spinal cord.
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Considering that the importance of cancer/testis (CT) antigens in multiple myeloma (MM) biology is still under investigation, the present study aimed to: (1) identify genes differentially expressed in MM using microarray analysis of plasma cell samples, separated according to the number of expressed CTs; (2) examine possible pathways related to MM pathogenesis; (3) validate the expression of candidate genes by quantitative real-time PCR (RQ-PCR). Three samples predominantly positive (>6 expressed), including the U266 cell line, and three samples predominantly negative (0 or 1 expressed CT for the 13 analyzed CT antigens), were submitted for microarray analysis. Validation by RQ-PCR from 24 MM samples showed that the ITGAS gene was downregulated in predominantly positive (>6 expressed CTs, p = 0.0030) and in tumor versus normal plasma cells (p = 0.0182). The RhoD gene was overexpressed in tumor plasma cells when compared to normal plasma cells (p = 0.0339). Results of the microarray analysis corroborate the hypothesis that MM could be separated into predominantly positive and predominantly negative expression. The differential expression of ITGA5 and RhoD suggests disruption of the focal adhesion pathway in MM and offers a new target field to be explored in this disease.
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Early-life events may induce alterations in neuronal function in adulthood. A crucial aspect in studying long-lasting effects induced by environmental interventions imposed to the animal several weeks before is finding a stable change that could be causally related to the phenotype observed in adulthood. In order to explain an adult trait, it seems necessary to look back to early life and establish a temporal line between events. The neonatal handling procedure is an experimental tool to analyze the long-lasting impact of early-life events. Aside from the neuroendocrine response to stress, neonatal handling also alters the functionality of the hypothalamus-pituitary-gonad (HPG) axis. Reductions in ovulation and surge of the luteinizing hormone (LH) on the proestrous day were shown in female rats. Considering the importance of the medial preoptic area (MPA) for the control of ovulation, the present study aimed to verify the effects of neonatal handling on the numerical density and cell size in the MPA in 11-day-old and 90-day-old female rats. Cellular proliferation was also assessed using BrdU (5-bromo-2`-deoxyuridine) in 11-day-old pups. Results showed that neonatal handling induces a stable reduction in the number of cells and in the size of the cell soma, which were lower in handled females than in nonhandled ones at both ages. Cellular proliferation in the MPA was also reduced 24 h after the last manipulation. The repeated mother-infant disruption imposed by the handling procedure ""lesioned"" the MPA. The dysfunction in the ovulation mechanisms induced by the handling procedure could be related to that neuronal loss. The study also illustrates the impact of an environmental intervention on the development of the brain. (C) 2008 Elsevier B.V. All rights reserved
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A dynamic modelling methodology, which combines on-line variable estimation and parameter identification with physical laws to form an adaptive model for rotary sugar drying processes, is developed in this paper. In contrast to the conventional rate-based models using empirical transfer coefficients, the heat and mass transfer rates are estimated by using on-line measurements in the new model. Furthermore, a set of improved sectional solid transport equations with localized parameters is developed in this work to reidentified on-line using measurement data, the model is able to closely track the dynamic behaviour of rotary drying processes within a broad range of operational conditions. This adaptive model is validated against experimental data obtained from a pilot-scale rotary sugar dryer. The proposed modelling methodology can be easily incorporated into nonlinear model based control schemes to form a unified modelling and control framework.place the global correlation for the computation of solid retention time. Since a number of key model variables and parameters are identified on-line using measurement data, the model is able to closely track the dynamic behaviour of rotary drying processes within a broad range of operational conditions. This adaptive model is validated against experimental data obtained from a pilot-scale rotary sugar dryer. The proposed modelling methodology can be easily incorporated into nonlinear model based control schemes to form a unified modelling and control framework.
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The personal computer revolution has resulted in the widespread availability of low-cost image analysis hardware. At the same time, new graphic file formats have made it possible to handle and display images at resolutions beyond the capability of the human eye. Consequently, there has been a significant research effort in recent years aimed at making use of these hardware and software technologies for flotation plant monitoring. Computer-based vision technology is now moving out of the research laboratory and into the plant to become a useful means of monitoring and controlling flotation performance at the cell level. This paper discusses the metallurgical parameters that influence surface froth appearance and examines the progress that has been made in image analysis of flotation froths. The texture spectrum and pixel tracing techniques developed at the Julius Kruttschnitt Mineral Research Centre are described in detail. The commercial implementation, JKFrothCam, is one of a number of froth image analysis systems now reaching maturity. In plants where it is installed, JKFrothCam has shown a number of performance benefits. Flotation runs more consistently, meeting product specifications while maintaining high recoveries. The system has also shown secondary benefits in that reagent costs have been significantly reduced as a result of improved flotation control. (C) 2002 Elsevier Science B.V. All rights reserved.