A utilização desse sistema especialista para a previsão dos índices zootécnicos é viável, pois o sistema tem bom desempenho para esta aplicação.Palavras-chave: sistemas especialistas; suinocultura; zootecnia de precisão Use of artificial neural networks on the prediction of zootechnical indexes on gestation and farrowing stages of swinesABSTRACT -The objective of this work was to evaluate the precision of Artificial Neural Networks (ANNs) to estimate zootechnical indexes, based on thermal and physiological variables of pregnant sows. This study was carried out from January to April 2005, in a swine industrial production farm in the gestation section with 27 primiparous gilts, allocated in individual pens and after on farrowing pens where it was quantified animal production indexes of piglets from the study. Therefore, an ANN backpropagation was implemented, with one input layer, one hidden layer, and one output layer with tangent sigmoidal transference functions. Air temperature and respiratory frequency were considered as input variables and weight of piglet at birth and the number of mummified piglets as output variables. The trained ANN presented a great generalization power, which enabled the prediction of the answer-variables. Characterization of the environment of gestation and maternity was appropriated if compared to the real data, with few under or overestimated tendencies of some values. The use of this specialist system to predict zootechnical indexes is viable because the system shows a good performance for this use.

Concerning the reduction of preslaughter death losses, high temperature and relative humidity in the tropics

Abstract:Introduction: Transforming growth factor beta 1 (TGFB1) and platelet-derived growth factor (PDGF) are the main cytokines related to hepatic fibrogenesis. Methods: RNA isolated from the platelets and hepatic tissue of 43 HCV carriers was used for quantitative polymerase chain reaction to determine TGFB1, PDGFA, and PDGFB RNA expression. Results: The mRNA expression of PDGFA in platelets was significantly lower in the group with advanced fibrosis than in the group with earlystage fibrosis. TGFB1 was more frequently expressed in platelets than in hepatic tissue, which was different from PDGFB. Conclusions: A pathway mediated by overexpression of TGFB1 via PDGFA in megakaryocytes could be involved in the development of fibrosis.Keywords: Hepatic fibrosis. PDGF. TGFB.Hepatic fibrosis, a consequence of various chronic stimuli, including infection with hepatitis C virus (HCV), is characterized by the progressive accumulation of extracellular matrix (ECM) components in the hepatic parenchyma, which leads to a progressive replacement of the functional tissue with scar tissue 1 .Hepatic stellate cells (HSCs) are considered the main cells producing ECM proteins 2 and their activation and proliferation are mediated by two cytokines, transforming growth factor beta 1 (TGFB1) and platelet-derived growth factor (PDGF). Both are secreted by HSCs, platelets, and other cells 3,4 .Transforming growth factor beta 1 is the major profibrogenic cytokine in the liver because of its contribution to fibrosis development via HSC activation and the regulation of gene expression associated with signaling cascades related to fibrosis 5,6 . Platelet-derived growth factor is the most potent mitogen for HSCs 7 . There are four different PDGF isoforms 8 and the PDGFB isoform is considered the most important mitogen for HSCs [7][8][9] . However, studies have demonstrated that PDGFA can also be considered an important profibrogenic agent, acting via TGFB1 induction 10 .Considering that platelets are major sources of TGFB1 and PDGF, which are growth factors involved in the development of liver fibrosis associated with chronic hepatitis C, and that studies have already demonstrated that platelets that accumulate in the liver during chronic hepatitis may be involved in hepatic fibrosis 11 , the aim of this study was to evaluate the expressions of PDGFA, PDGFB, and TGFB1 in hepatic tissue and platelets from HCV-infected patients presenting with varying degrees of hepatic fibrosis.Aliquots of ethylenediaminetetraacetic acid (EDTA)-anticoagulated peripheral venous blood and fragments of hepatic tissue were collected from 43 HCV-infected patients who presented at the Department of Internal Medicine, Gastroenterology Division, Botucatu Medical School, São Paulo State University [Universidade Estadual Paulista (UNESP)], Botucatu, SP, Brazil. The inclusion criteria were naïve patients infected with HCV genotype 1 who were aged >18 years, had undergone a liver biopsy before the start of antiviral treatment, and had signed informed consent. The exclu...

Teaching and learning strategies that use innovating technologies, such as the development of software or an understanding of the theoretical concepts of analytical equipment, can be essential tools for the construction of knowledge. In this way, this work describes the construction of an innovative and lowcost colorimeter using a RGB LED and a microcontroller board as a guide for teachers of undergraduate classes to prepare pedagogical activities using the proposed device as a learning object. The device was applied in experiments using methylene blue (MB), methylene orange (MO) and cobalt chloride (CC) aqueous solutions of different concentrations. Each one of these solutions has absorption peaks near the RGB colors. The results demonstrated that this lowcost device was able to identify unambiguous absorption peaks in the expected range of the MB, MO and CC absorption spectrums, allowing us to determine a feasible calibration curve for each tested solution.