Características de carcaça e do couro de bovinos precoces e superprecoces.

Objetivou-se avaliar o efeito do sistema de produção sobre características produtivas e do couro de bovinos cruzados precoces e superprecoces. Foram utilizados 36 animais, sendo 16 provenientes do sistema superprecoce (10 machos castrados e seis fêmeas), terminados em confinamento e 20 animais do sistema precoce (10 machos castrados e 10 fêmeas), terminados em pastagens, recebendo suplementação protéico energética (1 kg/dia/animal). Após o abate os couros foram processados até a etapa de couro semi-acabado, onde foram retiradas as amostras da região do dorsolombar para os ensaios físico-mecânicos de tração e rasgamento. Houve efeito do sistema de produção para ganho de peso total (GPT), ganho médio diário (GMD), área de olho de lombo (AOL), espessura de gordura subcutânea (EGS), marmoreio, peso da pele ao abate (PPe1) e perdas com a padronização, com menores médias para animais precoces. As perdas apresentadas pelas fêmeas foram 14,48 e 6,88 kg, e para os machos castrados 9,32 e 4,84 kg, respectivamente para superprecoces e precoces. As médias de PA, peso da pele padronizada e área do couro Wet-blue dos machos castrados foram 473,60 kg, 40,60 kg e 4,52 m², respectivamente, para superprecoces e 462,83 kg, 29,77 kg e 4,31 m², respectivamente, para precoces. Não houve efeito de sexo e de sistema de produção para as características avaliadas nos ensaios físicos mecânicos no couro de bovinos precoces e superprecoces

An optimized mice training protocol suitable for CatWalk, a computer-assisted gait analysis system

Movement abnormalities are important symptoms in clinical neurology. Neurological diseases such as Parkinson's disease (PD), multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), stroke and pain present with abnormalities of motor function and severe locomotor deficits. Over the years, many methods have been developed to analyze locomotor behavior in small laboratory animals, particularly in rat. The CatWalk, a computer-assisted automated quantitative gait analysis system, allows rapid and objective quantification of a large number of gait parameters. In comparison to ink-test or similar approaches, previously used to assess static locomotor alterations, CatWalk can also obtain dynamic parameters. Despite the extensive use of the mouse in experimental models for neurological disease there have been relatively few studies on CatWalk in mouse. Furthermore, few information are available regarding methodological aspects on training prior to test. The aims of the present study are: (1) to provide reliable and reproducible results on over-ground locomotion in intact mouse using three different training protocol and, (2) to analyze the effect of training protocol on over-ground locomotion. In this study we tested three different experimental trainings, in order to get the best protocol for the use of the CatWalk in mice models. Animals were trained to run the walkway for different duration, either 11, 4 or 3 days, providing groups A, B and C respectively; mice of groups A and B were left to cross freely the walkway, while group C was forced to run only in one direction. Mice of groups A and B were subjected to a food deprivation (diet of 75% and then of 30%), while ad libitum food was available for mice of group C. Furthermore, mice of groups B and C were rewarded with high palatable food placed in a cage at the end of the runway, for motivating them. We objectively quantified a large number of gait parameters during over-ground locomotion and we focused for the first time on relation between animal weight and basic gait parameters because different training protocols can act as confounder for the interpretation of the results. The obtained results can thus serve as a template for studying changes in locomotor performance in mouse due to neurological disease or trauma to the CNS and may provide relevant information that can be advantageous to select a particular experimental protocol to be used in different models of movement disorders

Island growth mode in pulsed laser deposited ferroelectric BaTiO3 thin films : the role of oxygen pressure during deposition

Pulsed laser deposition is widely used to grow BaTiO3 thin films. We investigated the influence of oxygen pressure during growth on the topography, microstructure, and roughness of ferroelectric epitaxial BaTiO3 thin films. It also presented an analysis of the epitaxial growth mode and defects throughout the film thickness using aberration-corrected transmission electron microscopy. Although ferroelastic (twin boundary) domain walls are absent, several misfit dislocations were observed and might be the primary cause of the observed island growth mode54513944CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP309354/2015-988887.149376/2017-00; 88887.145777/2017-002012/51198-2; 2015/15787-1The authors would like to thank the Brazilian National Nanotechnology Laboratory (LNNano) for technical support during electron microscopy work (project ME22332) and X-ray diffraction experiments. The atomic force microscope was funded by FAPESP (Project No. 2012/51198-2). F. R. E. acknowledges fellowship from CAPES (88887.149376/2017-00). L. G. M. M acknowledges fellowship from FAPESP (2015/15787-1). F. L. A. V. acknowledges fellowship from CAPES (88887.145777/2017-00). J. C. C. acknowledges CNPq support under project 309354/2015-

Magnetic properties of synthetic eumelanin - Preliminary results

We report an experimental and theoretical study of magnetic properties of synthetic eumelanin. The magnetization curves are determined by using both a vibrating sample magnetometer and a superconducting quantum interferometer device in an extended range of magnetic fields ranging from -10 kOe to 10 kOe at different temperatures. We find that the eumelanin magnetization can be qualitatively explained in terms of a simple model of dipolar spheres with an intrinsic magnetic moment. The latter one is experimentally measured by using X-band electron paramagnetic resonance. Our findings indicate that synthetic melanins are superparamagnetic

Magnetoresistance in granular magnetic tunnel junctions with Fe nanoparticles embedded in ZnSe semiconducting epilayer

International audienceWe have investigated transport properties of iron (Fe) nanoparticles embedded in zinc selenide (ZnSe) semiconducting epilayers prepared by molecular beam epitaxy. Both positive and negative tunneling magnetoresistances (TMRs) were measured depending on the applied voltage biases and on the temperature. A slow reduction of the TMR magnitude with temperature was detected and it could be explained in terms of a crossover between direct/resonant tunneling and variable range hopping. The temperature behavior of the magnetoresistance is a clear signature of tunneling and hopping mechanisms mediated by the ZnSe barrier localized states. (C) 2008 American Institute of Physics

New evidences of a possible role of vascular alterations and cytokines in absence epilepsy

The actions of proinflammatory cytokines in the CNS are only partially discovered. Some cytokines have been recently shown to affect neurotransmitters or are required to preserve the synaptic strength at excitatory synapses, or affect the expression of various neuropeptides and neurotrophic factors in several brain regions. Changes in the immune system may change the excitability of the CNS and alter the susceptibility of exogenous induced or genetically determined types of epilepsy. Here we investigate the role of two cytokines, IL-1\u3b2 and TNF-\u3b1 in WAG/Rij rats, a genetic model of absence epilepsy, the most pure form of generalized epilepsy characterized in the EEG by widespread bilaterally synchronous spike-wave discharges (SWDs) caused by thalamo-cortical oscillations. Our hypothesis is that cerebral blood flow alterations and cytokines/chemokines release can modulate the occurrence of SWDs. In this view, gene-array analysis for cell signaling pathways involved in SWDs in different cerebral areas, and qPCR data were correlated with EEG and MRS data. Furthermore, we analyzed the blood serum by ELISA method for TNF-\u3b1 and IL-1\u3b2 in control and epileptic animals; in addition, we injected i.p. both controls and WAG/Rij rats by TNF-\u3b1 (2\ub5g/kg) and IL-1\u3b2 (2\ub5g/kg). Our results indicate that a) cerebral blood volume and flow are altered in epileptic animals vs controls; b) slight differences have been noticed in TNF-\u3b1 basal serum levels in early developmental stages (2 months) in WAG/Rij vs controls; c) TNF-\u3b1 and IL-1\u3b2 injections induced a large increase in the number of SDWs in WAG/Rij animals following a different time-pattern; d) MRS data indicate that WAG/Rij rats have higher levels of Glutamate vs controls, both in the thalamus and in the cerebral cortex; e) since cytokines have been reported to alter the neurotransmitters levels, we would like to further investigate the possible role of these mechanisms in this animal model.Summarizing, we hereby reported some evidences on the possible neuromodulator functions of inflammatory cytokines and absence epilepsy. Further study will allow to better elucidate these \u201cliaisons dangereuses\u201d