169 resultados para OPERATIONAL PARAMETERS


Relevância:

20.00% 20.00%

Publicador:

Resumo:

ABSTRACT: Clinical and complementary analysis are good alternatives to evaluate physiological demand in performance horses. The aim of this study was to assess whether the physical effort variation of the three-day Vaquejada competition (a Brazilian form of bullfighting) reflected in clinical and blood gasometric changes. During the competition eight sprints have been performed on the first day (D1), eight on the second (D2) and three on the last one (D3). Ten horses were evaluated by checking heart and respiratory rates and collecting blood samples for use in portable chemistry analyzer. Through that, it was assessed potential of hydrogen ion (pH), carbon dioxide pressure (pCO2), bicarbonate (HCO3-) and titratable base concentration (cBase). Evaluations were carried with resting of at least twenty hours, before physical activity (D0), as control parameter, and up to thirty minutes after each sprint. Clinical parameters have increased on D1, D2 and D3, when compared to D0, which demonstrated the increased demand for substrate and oxygen to the cells.. Blood gasometric trial showed reductions of all variables, most marked between D1 and D2. It was verified less alteration of all clinical and blood gasometric parameters in D3 against D0. We concluded that the change effort between days of competition influenced the clinical and blood gas parameters, demonstrating appropriate physiological response. The data were presented as mean and standard error of the mean (mean ± SEM) obtained in different days. Normality was confirmed by the Kolmogorov-Sminov test and data were compared by one-way ANOVA, followed by post-test Holm-Sidak (GraphPad Prism 2.6 for Windows, GraphPad Software, San Diego, CA, USA). P≤0.05 was considered as statistically significant.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Abstract: The aim of this study was to assess the cardiopulmonary effects, the onset time after the administration of a detomidine/ketamine combination, and the recovery from anesthesia of cougars (Puma concolor) anesthetized with detomidine/ketamine and isoflurane or sevoflurane for abdominal ultrasound imaging. Fourteen animals were randomly allocated into two experimental groups: GISO (n=7) and GSEVO (n=7). Chemical restraint was performed using 0.15mg/kg detomidine combined with 5mg/kg ketamine intramuscularly; anesthesia induction was achieved using 2mg/kg propofol intravenously and maintenance with isoflurane (GISO) or sevoflurane (GSEVO). The following parameters were assessed: heart rate, respiratory rate, systolic and diastolic arterial blood pressure, mean arterial blood pressure, oxyhemoglobin saturation, rectal temperature, central venous pressure, and end-tidal carbon dioxide. The time to sternal recumbency (TSR) and time to standing position (TSP) were also determined. There was not statistically significant difference for the cardiopulmonary variables or TSP whereas TSR was significantly shorter in GSEVO. The time to onset of anesthesia was 11.1±1.2 minutes and 11.3±1.8 minutes for GISO and GSEVO, respectively. The anesthesia of cougars with detomidine/ketamine and isoflurane or sevoflurane was conducted with safety, cardiopulmonary stability, and increased time to sternal recumbency in the GISO group.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Abstract: This study aimed to determine whether prepartum antimicrobial and/or Escherichia coli J5 vaccination in dairy heifers influence the milk production, milk quality, and estimate their economic benefit. Thus, 33 dairy heifers were enrolled in four groups using a split-splot design. Groups were: (G1) prepartum antimicrobial infusion and vaccination with an E. coli J5 bacterin, (G2) prepartum antimicrobial infusion, (G3) vaccination with an E. coli J5 bacterin, and (G4) control heifers. Composite milk samples for somatic cell count, total bacteria count and milk composition were collected 15 days after calving and every 15 days until the end of the experiment. Bacteriological analysis was carried out at the end of study. The milk production and the incidence of clinical cases of mastitis, as well as the costs associated with them were recorded. The results demonstrate a reduction on clinical mastitis rates by preventive strategies, which implicated in lower volume of discarded milk (0.99, 1.01, 1.04 and 3.98% for G1, G2, G3 and G4, respectively) and higher economic benefit. Thus, in well-managed dairy herds the prevention of heifer mastitis by vaccination or antimicrobial therapy can reduce the amount of antimicrobials needed to treat clinical mastitis cases and the days of discarded milk.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Abstract: The present paper reports blood gas analysis, hematologic and micro bacteriologic information on four female Red-billed curassows, rescued from illegal wild animal trading, that were undergoing habilitation for reintroduction into the wild through Projeto Centrofauna/Botucatu-SP. There is a lack of physiological data on this species, endemic to the region of Atlantic Forest (Mata Atlântica), now under threat of extinction. This lack of information makes the clinical evaluation of these birds very difficult and has a direct and adverse effect on any of these birds received for medical treatment in hospitals, veterinary clinics and centers for research and conservation, as well as in reintroduction centers.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

One of the main complexities in the simulation of the nonlinear dynamics of rigid bodies consists in describing properly the finite rotations that they may undergo. It is well known that, to avoid singularities in the representation of the SO(3) rotation group, at least four parameters must be used. However, it is computationally expensive to use a four-parameters representation since, as only three of the parameters are independent, one needs to introduce constraint equations in the model, leading to differential-algebraic equations instead of ordinary differential ones. Three-parameter representations are numerically more efficient. Therefore, the objective of this paper is to evaluate numerically the influence of the parametrization and its singularities on the simulation of the dynamics of a rigid body. This is done through the analysis of a heavy top with a fixed point, using two three-parameter systems, Euler's angles and rotation vector. Theoretical results were used to guide the numerical simulation and to assure that all possible cases were analyzed. The two parametrizations were compared using several integrators. The results show that Euler's angles lead to faster integration compared to the rotation vector. An Euler's angles singular case, where representation approaches a theoretical singular point, was analyzed in detail. It is shown that on the contrary of what may be expected, 1) the numerical integration is very efficient, even more than for any other case, and 2) in spite of the uncertainty on the Euler's angles themselves, the body motion is well represented.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A three degree of freedom model of the dynamic mass at the middle of a test sample, resembling a Stockbridge neutraliser, is introduced. This model is used to identify the hereby called equivalent complex cross section flexural stiffness (ECFS) of the beam element which is part of the whole test sample. This ECFS, once identified, gives the effective cross section flexural stiffness of the beam as well as its effective damping, measured as the loss factor of an equivalent viscoelastic beam. The beam element of the test sample may be of any complexity, such as a segment of stranded cable of the ACSR type. These data are important parameters for the design of overhead power transmission lines and other cable structures. A cost function is defined and used in the identification of the ECFS. An experiment, designed to measure the dynamic masses of two test samples, is described. Experimental and identified results are presented and discussed.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A three degree of freedom model of the dynamic mass at the middle of a test sample, resembling a Stockbridge neutraliser, is introduced. This model is used to identify the hereby called equivalent complex cross section flexural stiffness (ECFS) of the beam element which is part of the whole test sample. This ECFS, once identified, gives the effective cross section flexural stiffness of the beam as well as its effective damping, measured as the loss factor of an equivalent viscoelastic beam. The beam element of the test sample may be of any complexity, such as a segment of stranded cable of the ACSR type. These data are important parameters for the design of overhead power transmission lines and other cable structures. A cost function is defined and used in the identification of the ECFS. An experiment, designed to measure the dynamic masses of two test samples, is described. Experimental and identified results are presented and discussed.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This work presents recent results concerning a design methodology used to estimate the positioning deviation for a gantry (Cartesian) manipulator, related mainly to structural elastic deformation of components during operational conditions. The case-study manipulator is classified as gantry type and its basic dimensions are 1,53m x 0,97m x 1,38m. The dimensions used for the calculation of effective workspace due to end-effector path displacement are: 1m x 0,5m x 0,5m. The manipulator is composed by four basic modules defined as module X, module Y, module Z and terminal arm, where is connected the end-effector. Each module controlled axis performs a linear-parabolic positioning movement. The planning path algorithm has the maximum velocity and the total distance as input parameters for a given task. The acceleration and deceleration times are the same. Denavit-Hartemberg parameterization method is used in the manipulator kinematics model. The gantry manipulator can be modeled as four rigid bodies with three degrees-of-freedom in translational movements, connected as an open kinematics chain. Dynamic analysis were performed considering inertial parameters specification such as component mass, inertia and center of gravity position of each module. These parameters are essential for a correct manipulator dynamic modelling, due to multiple possibilities of motion and manipulation of objects with different masses. The dynamic analysis consists of a mathematical modelling of the static and dynamic interactions among the modules. The computation of the structural deformations uses the finite element method (FEM).

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Several tools of precision agriculture have been developed for specific uses. However, this specificity may hinder the implementation of precision agriculture due to an increasing in costs and operational complexity. The use of vegetation index sensors which are traditionally developed for crop fertilization, for site-specific weed management can provide multiple utilizations of these sensors and result in the optimization of precision agriculture. The aim of this study was to evaluate the relationship between reflectance indices of weeds obtained by the GreenSeekerTM sensor and conventional parameters used for weed interference quantification. Two experiments were conducted with soybean and corn by establishing a gradient of weed interference through the use of pre- and post-emergence herbicides. The weed quantification was evaluated by the normalized difference vegetation index (NDVI) and the ratio of red to near infrared (Red/NIR) obtained using the GreenSeekerTM sensor, the visual weed control, the weed dry matter, and digital photographs, which supplied information about the leaf area coverage proportions of weed and straw. The weed leaf coverage obtained using digital photography was highly associated with the NDVI (r = 0.78) and the Red/NIR (r = -0.74). The weed dry matter also positively correlated with the NDVI obtained in 1 m linear (r = 0.66). The results indicated that the GreenSeekerTM sensor originally used for crop fertilization could also be used to obtain reflectance indices in the area between rows of crops to support decision-making programs for weed control.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The objective of this study was to determine changes in gas exchange and inhibition of EPSPs, based on the accumulation of shikimic acid in horseweed biotypes resistant and sensitive to glyphosate. Two experiments were conducted in a factorial model. The first one evaluated horseweed biotypes (one resistant and one susceptible to glyphosate), and herbicide rates (0 and 1,080 g a.e. ha ¹) applied on the weed. In the second experiment, the horseweed biotypes (susceptible and resistant to glyphosate) were evaluated in five periods as following: 0, 3, 7, 10, and 14 days after herbicide application (DAH). The photosynthetic rate, transpiration, carboxylation efficiency, and water efficiency were determined using an infrared gas analyzer (IRGA), and shikimic acid concentration by HPLC. The application of glyphosate damaged the photosynthetic parameters of the susceptible biotype, causing complete inhibition of the photosynthetic rate, transpiration rate, carboxylation efficiency and water use efficiency, starting from the 7 DAH. On the other hand, total inhibition of the photosynthetic parameters was not observed for the resistant biotype. Shikimic acid accumulation occurred in both biotypes after glyphosate application but the susceptible biotype had the highest concentrations, indicating greater sensitivity of the enzyme EPSPs. The accumulation of shikimic acid in the resistant biotype indicates that the mechanism of resistance is not related to the total insensitivity of the enzyme EPSPs to glyphosate and/or that other resistance mechanisms may be involved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The aim of this study was to investigate the photosynthetic performance in populations of two legume tree species, Stryphnodendron adstringens (Mimosoideae), typical from Cerrado, and Cassia ferruginea (Caesalpinoideae) from the Atlantic Rain Forest. The photosynthetic traits were assessed by measures of chlorophyll fluorescence in progenies of naturally pollinated plants from three populations of S. adstringens and a population of C. ferruginea. Plants of S. adstringens growing under similar conditions of C. ferruginea plants demanded higher light values for photosynthesis saturation, 600 µmol.m-2.s-1 and 350 µmol.m-2.s-1 respectively, and showed higher intrinsic photosynthetic efficiency of photosystem II, Fv/Fm of 0.814 versus 0.783 in C. ferruginea. The highest values of Fv/Fm observed in S. adstringens can explain the highest electron transport rates (ETR) obtained for this species. No significant differences were found among progenies from different C. ferruginea trees nor among populations of S. adstringens, and only in few cases, variation among progenies within populations were found for S. adstringens plants. The fact that fluorescence parameters distinguished species but not populations or most of progenies may be related to low intraspecific genetic variation of these chlorophyll fluorescence traits or due to lack of expression on genetic differences in plants under no stressful conditions.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Green algal species and their association with physicochemical parameters in some manmade ponds in Zaria, Nigeria were studied from November 2005 to August 2006. Phytoplankton and water samples were collected, preserved and analyzed using standard methods. A total of 27 green algal species divided into 16 families were recorded. Shannon diversity indices ranged from 1.75 to 2.39 in all ponds, dominance index from 0.14 to 0.23 and species evenness 0.56 to 0.64. Closterium sp. and Rhizoclonium hookeri Kuetz. were positively associated with the concentration of Fe, however they were negatively correlated (sensitive) to alkalinity, total dissolved solids and electrical conductivity. Stichococcus bacillaris Naegeli, Staurastrum rotula Nordst. and Sphaeroplea sp. had significant positive relationship with biochemical oxygen demand (BOD), Mn, and Mo levels in the water. Pseudouvella americana (Snow) Wille. and Scenedesmus quadricauda (Turp.) de Bréb. showed a close positive association with alkalinity but were sensitive to Fe, BOD, Mn and Mo. The species reported here showed closed association with physicochemical factors in these ponds.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Estimates of genetic and phenotypic parameters were obtained by using data from families of a recurrent selection program in rice. An experiment using population CNA-IRAT 4ME/1/1 was conducted at two locations (Lambari and Cambuquira) in the State of Minas Gerais, Brazil. At Lambari, families S0:2 and S0:3 were assessed during crop seasons 1992/1993 and 1993/1994, respectively. In the Cambuquira trial, only S0:3 families were tested in 1993/1994. The experimental design was a 10 x 10 lattice with three replications. The following traits were assessed: grain yield (GY), mean number of days to flowering (FL), plant height (PH), and the incidence of neck blast (NB) caused by Pyricularia grisea and grain staining (GS) caused by Drechslera oryzae. This population proved to be promising for recurrent selection, as it had high average yield and genetic variability. Heritability estimates obtained using variance components were generally greater than estimates of realized heritability, and heritability obtained by parent-offspring regression

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In view of the importance of the intestine in the osmoregulation of freshwater fishes, we determined the effects of oxytocin, urotensin II (UII), and aldosterone added to the serosal side of the isolated posterior intestine of the freshwater-adapted teleost Anguilla anguilla on electrophysiological parameters. Oxytocin decreased the short-circuit current (SCC) and transepithelial potential difference (TPD) at concentrations of 1 and 10 mU/ml (to 50% and 42% of control values, respectively), but did not alter these parameters at a concentration of 0.1 mU/ml. UII reduced SCC and TPD at concentrations of 10 nM, 50 nM and 100 nM (to 85% of control values), but increased these parameters at the concentration of 500 nM (to 115% of control values). Aldosterone did not alter SCC or TPD at the concentrations tested (10 nM and 100 nM). Oxytocin may open Na+ channels in the apical membrane, allowing the flow of Na+ to the serosa, reducing SCC and TPD. Should this hypothesis be correct, oxytocin would be important for freshwater adaptation, since it would increase Na+ absorption. The reduction of SCC and TPD in the posterior intestine of A. anguilla induced by UII is evidence that this neurohormone is also important for freshwater adaptation in teleosts. Aldosterone did not show this effect probably due to the lack of receptors in this organ

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Innate and acquired resistance to rabies infection was investigated in mice genetically selected for high (H) or low (L) antibody responsiveness from selections I, III and IV and in mice selected for maximal (AIRmax) or minimal (AIRmin) acute inflammatory reaction. These mouse lines were infected intramuscularly with different virus dilutions and the LD50 was determined. The HIII and HIV mouse lines were more susceptible than the LIII and LIV lines and the HI line showed a discrete but higher resistance than the LI line. Analysis of the interline (H x L) F1 hybrids from selections III and IV indicated different dominance effects on the "resistant" and" susceptible" phenotypes when the route of vaccination was changed. No differences were observed between the AIRmax and AIRmin mice, suggesting that inflammation plays a minor role in the resistance to rabies virus. The comparison of LD50 in mice vaccinated by distinct routes showed that the highest interline difference occurred after intramuscular vaccination (250-fold between H and L and 800-fold between F1 and L). These results indicate that different mechanisms may participate in acquired antirabies resistance