Effect of imidocarb dipropionate in brazilian anaplasmosis and babesiosis     

J. H. Patarroyo  M. F. Ribeiro  M. I. Vargas 《Tropical animal health and production》1982,14(4):234-234

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Immunocytochemical detection of amylase, carboxypeptidase A, carcinoembryonic antigen and alpha 1-antitrypsin in carcinomas of the exocrine pancreas of the dog.     

R Rabanal  D Fondevila  A Vargas  A Ramis  J Badiola  L Ferrer 《Research in veterinary science》1992,52(2):217-223

The immunocytochemical detection of amylase, carboxypeptidase A, alpha 1-antitrypsin, carcinoembryonic antigen (CEA) and keratin in normal canine pancreatic tissue and in carcinomas of the exocrine pancreas of the dog is described. In the normal pancreas, the acinar cells contain amylase, carboxypeptidase and alpha 1-antitrypsin. The pancreatic ducts react with the antikeratin antibody. Twelve out of 14 pancreatic exocrine carcinomas showed immunoreaction with antiamylase antibody, and 10 with anticarboxypeptidase antibody. Five neoplasms reacted with anti-CEA antibody and three with the anti-alpha 1-antitrypsin antibody. It was not possible to find any systematic difference in the immunocytochemical profiles of acinar, tubular and undifferentiated carcinomas. These results indicate that immunocytochemical marking of amylase and carboxypeptidase is of value in the diagnosis of pancreatic neoplasms in the dog, especially if metastasis is the only material available for study and the tumour does not show any diagnostic feature on routine light microscope preparations.  相似文献   

Genetic parameter estimation for pre- and post-weaning traits in Brahman cattle in Brazil     

Giovana Vargas  Marcos Eli Buzanskas  Diego Gomes Freire Guidolin  Daniela do Amaral Grossi  Alexandre da Silva Bonifácio  Raysildo Barbosa Lôbo  Ricardo da Fonseca  João Ademir de Oliveira  Danísio Prado Munari 《Tropical animal health and production》2014,46(7):1271-1278

Beef cattle producers in Brazil use body weight traits as breeding program selection criteria due to their great economic importance. The objectives of this study were to evaluate different animal models, estimate genetic parameters, and define the most fitting model for Brahman cattle body weight standardized at 120 (BW120), 210 (BW210), 365 (BW365), 450 (BW450), and 550 (BW550) days of age. To estimate genetic parameters, single-, two-, and multi-trait analyses were performed using the animal model. The likelihood ratio test was verified between all models. For BW120 and BW210, additive direct genetic, maternal genetic, maternal permanent environment, and residual effects were considered, while for BW365 and BW450, additive direct genetic, maternal genetic, and residual effects were considered. Finally, for BW550, additive direct genetic and residual effects were considered. Estimates of direct heritability for BW120 were similar in all analyses; however, for the other traits, multi-trait analysis resulted in higher estimates. The maternal heritability and proportion of maternal permanent environmental variance to total variance were minimal in multi-trait analyses. Genetic, environmental, and phenotypic correlations were of high magnitude between all traits. Multi-trait analyses would aid in the parameter estimation for body weight at older ages because they are usually affected by a lower number of animals with phenotypic information due to culling and mortality.  相似文献   

Parameters of the Reproductive Tract,Spermatogenesis, Daily Sperm Production and Major Seminal Plasma Proteins of Tropically Adapted Morada Nova Rams     

FML Sousa  CH Lobo  ESB Menezes  JPA Rego  RV Oliveira  AC Lima‐Souza  M Fioramonte  FC Gozzo  RCFF Pompeu  MJD Cândido  JT Oliveira  AA Moura 《Reproduction in domestic animals》2014,49(3):409-419

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Immunolocalization of the Cholesterol Transporters ABCA1 and ABCG1 in Canine Reproductive Tract Tissues and Spermatozoa     

N Palme  AC Becher  M Merkl  M Glösmann  C Aurich  S Schäfer‐Somi 《Reproduction in domestic animals》2014,49(3):441-447

The mammalian sperm membrane undergoes cholesterol efflux during maturation and fertilization. Although ATP‐binding cassette (ABC) transporters are known to transport cholesterol through cell membranes in other organs, their presence in canine testis, epididymis and sperm has not been proven to date. Hence, the aim of the present study was to localize the ABC transporters ABCA1 and ABCG1 in canine testicular and epididymidal tissue as well as in spermatozoa membranes. To this end, semen samples from 12 dogs as well as testicles and epididymides of four young and healthy dogs were prepared for immunohistochemistry, respectively. Capacitation and acrosome reaction (AR) were induced in aliquots of the semen samples before immunostaining to assess changes in the expression of ABCA1 and ABCG1. Evaluation by confocal microscopy revealed the presence of both ABCA1 and ABCG1 in canine testicles and of ABCA1 in the epididymides. In spermatozoa, only ABCA1 immunoreactivity was detected, mainly in the region of the acrosome and midpiece. After induction of capacitation, ABCA1 signal persisted in the acrosome but disappeared after AR, indicating a loss of ABCA1 with the loss of the acrosome. We conclude that ABCA1 and ABCG1 are expressed in canine testis, whereas only ABCA1 is expressed in epididymis and spermatozoa membrane, both transporters probably contributing to the regulation of membrane cholesterol content.  相似文献   

THE PERUVIAN INSTITUTE OF CHEMICAL ENGINEERS     

Vargas J 《Science (New York, N.Y.)》1945,101(2632):578-579

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Tools for optimizing management of spatially-variable fields   总被引：5，自引：0，他引：5  

H. W. G. Booltink  B. J. van Alphen  W. D. Batchelor  J. O. Paz  J. J. Stoorvogel  R. Vargas 《Agricultural Systems》2001,70(2-3):445-476

Efficient use of agro-chemicals is beneficial for farmers as well as for the environment. Spatial and temporal optimization of farm management will increase productivity or reduce the amount of agro-chemicals. This type of management is referred to as Precision Agriculture. Traditional management implicitly considers any field to be a homogeneous unit for management: fertilization, tillage and crop protection measures, for example, are not varied within a single field. The question for management is what to do when. Because of the variability within the field, this implies inefficient use of resources. Precision agriculture defines different management practices to be applied within single, variable fields, potentially reducing costs and limiting adverse environmental side effects. The question is not only what and when but also where. Many tools for management and analysis of spatial variable fields have been developed. In this paper, tools for managing spatial variability are demonstrated in combination with tools to optimize management in environmental and economic terms. The tools are illustrated on five case studies ranging from (1) a low technology approach using participatory mapping to derive fertilizer recommendations for resource-poor farmers in Embu, Kenya, (2) an example of backward modelling to analyze fertilizer applications and restrict nitrogen losses to the groundwater in the Wieringermeer in The Netherlands, (3) a low-tech approach of precision agriculture, developed for a banana plantation in Costa Rica to achieve higher input use efficiency and insight in spatial and temporal variation, (4) a high-tech, forward modelling approach to derive fertilizer recommendations for management units in Zuidland in The Netherlands, and (5) a high-tech, backward modelling approach to detect the relative effects of several stress factors on soybean yield.  相似文献   

Modelling the effect of El Niño on the persistence of small populations: The Galápagos penguin as a case study     

F. Hernán Vargas  Robert C. Lacy  Antje Steinfurth  P. Dee Boersma 《Biological conservation》2007,137(1):138-148

Small populations are vulnerable to long-term declines, even where short-term censuses indicate increasing trends in numbers. Census data for the Galápagos penguin (Spheniscus mendiculus) collected between 1970 and 2004 provide evidence that despite year-to-year population increases detected in most of the annual censuses, the strong El Niño events of 1982-83 and 1997-98 were followed by population declines of more than 60% from which the species has yet to recover. Such large declines raise concerns about the future viability of the species because the frequency and severity of El Niño events are predicted to increase. We used the simulation software VORTEX to evaluate the potential effects of El Niño on the risk of extinction of the Galápagos penguin population and its four constituent subpopulations. Weak and strong El Niño events were treated as catastrophes, with varying frequencies, which simulated past, current and future effects on the penguin population. The “Current El Niño” scenario, based on the frequency of El Niño events recorded in the Galápagos between 1965 and 2004, indicated an approximately 30% probability of extinction within the next 100 years for the penguin population. More ominously, the species may be at a greater risk if the frequency of strong El Niño episodes increases only marginally. A probability of extinction greater than 80% was predicted when the current frequency (5%) of strong El Niño events was doubled (to 10%). The probabilities of extinctions were higher for each subpopulation treated individually, ranging from 34% for Isabela and Fernandina, 64% for Bartolomé-Santiago to 78% for the smallest subpopulation on Floreana. Sensitivity analyses identified survival of penguins during El Niño events and sex ratio as influential parameters. The estimates of extinction risk may be conservative as other threats associated with increased human activities on the islands may further compromise species persistence.  相似文献   

A description of the growth and moulting of feathers in commercial broilers     

L. Vargas  N. K. Sakomura  B. B. Leme  F. A. P. Antayhua  D. Campos 《British poultry science》2020,61(4):454-464

ABSTRACT

1. Changes in feather length and weight and daily losses of down, contour feathers, remiges and retrices were studied in two commercial broiler strains to determine feather growth and moult in broilers up to 112 d of age.

2. Ten pens of 20 chicks for each sex x strain were fed adequate amounts of dietary protein in a four-phase feeding programme. Ten birds were sampled per genotype at 14, 28, 42, 56, 70, 84, 98 and 112 d. Feather loss was determined for individual birds caged within a nylon net.

3. All feathers were dry-plucked from each of seven tracts, with representative feathers from the capital-cervical, dorsopelvic and interscapular, pectoral and femoral tracts being randomly selected. Three rectrices of the dorsocaudal tract and three primaries and secondaries of the humeral-alar tract of the right wing were evaluated.

4. The length of the selected feathers was measured, and the feathers from each tract and from the whole bird were weighed.

5. A wide range of rates of maturing (0.0250–0.0907/d) and mature weights (9.62–52.9 g) were evident between sampled tracts.

6. Feather weight failed to predict some moults which were detected by the measurement of feather losses. From the weight data, moulting was evident only in the humeral-alar and dorsocaudal tracts, whereas, when daily losses were measured, contour feathers accounted for over 0.7 proportion of feather losses. Logistic equations adequately described the cumulative losses of down, contour feathers and remiges.

7. Feather loss needs to be considered when feather growth is determined from feather weight at different ages.

8. The rate of maturing (B) of feathers was numerically higher in Ross males and females than in the Cobb strain. In females, B was higher than in males (0.0483 vs. 0335/d) but the mature weight was lower (162 vs. 230 g).  相似文献   

Relationship between reproductive and productive traits in Holstein cattle using multivariate analysis     

Pablo Dominguez-Castaño  Matheus Henrique Vargas de Oliveira  Lenira El Faro  Josineudson Augusto II de Vasconcelos Silva 《Reproduction in domestic animals》2020,55(7):770-776

Multivariate procedures are used for the extraction of variables from the correlation matrix of phenotypes in order to identify those traits that explain the largest proportion of phenotypic variation and to evaluate the relationship structure between these traits. The reproductive traits (days from calving to first estrus [CFE], days from calving to last service [CLS], calving interval [CI] and gestation length [GL]) and milk production traits (milk yield at 305 days of lactation [MY305], peak yield [PY] and milk yield per day of calving interval [MYCI]) of 5,217 Holstein females (primiparous and multiparous) were measured. Principal component analysis (PCA) and factor analysis of the correlation matrix were used to estimate the correlation between traits. Analysis grouped the seven traits into three principal components and four latent factors that retained approximately 81.5% and 88.9% of the total variation of the data, respectively. The production variables exhibited positive phenotypic correlation coefficients of high magnitude (>.67). The phenotypic correlation estimates between the productive and reproductive traits were low, ranging from .13 to .22. A strong association (.99) was observed between CLS and CI. Our results indicate that multivariate analysis was effective in generating correlations between the traits studied, grouping the seven traits in a smaller number of variables that retained approximately 81% of the total variation of the data.  相似文献