3,400 research outputs found

    Características dos cortes comerciais da carne de tourinhos e novilhas cruzados, terminados em confinamento.

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    Este trabalho teve como objetivo principal avaliar os pesos dos cortes comerciais de carne de 27 tourinhos e 31 novilhas, filhos de vacas ½ Angus x ½ Nelore e vacas ½ Simental x ½ Nelore, inseminadas com sêmen de touros das raças Angus e Limousin. Os animais foram desmamados aproximadamente aos 250 dias de idade, distribuídos de acordo com sexo e grupo genético, confinados em baias individuais descobertas e com consumo ad libitum. Os machos apresentaram maiores médias (P≤0,05) que as fêmeas para o peso do dianteiro, do traseiro especial e da ponta de agulha. Os machos tiveram maiores médias (P≤0,05) para os cortes dianteiros (paleta, músculo, acém, pescoço, peito e ossos) que as fêmeas. Para os cortes traseiros (contrafilé, filé mignon, picanha, picanha grill, alcatra, coxão mole, coxão duro, lagarto, patinho e ossos), os machos também apresentaram maiores médias (P≤0,05) que as fêmeas. Já para aparas comestíveis (bananinha, músculo traseiro, aranha, capa do filé e cordão), as fêmeas apresentaram maiores médias (P≤0,05) que os machos. Em relação ao fraldão, os animais filhos de Angus tiveram maior média (P≤0,05) que os filhos de Limousin. Todos os cruzamentos avaliados possibilitaram o abate dos animais aos 12 meses de idade, independentemente do sexo

    MICROALGAE BIOPOLYMERS: A REVIEW

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    Algae are ubiquitous organisms whose capabilities have drawn much attention as of late in the bioengineering field due to their potential to enable a wide range of bioproducts. Microalgae are ideal organisms for the application of the biorefinery concept since they can be grown in wastewater and, at the same time, produce many products of commercial interest. These microorganisms are also known for their resilience to extreme environmental conditions and suitable cell growth rates. Beyond the known potential for biofuel production, these microorganisms can still produce other compounds, being lipids, pigments, vitamins, proteins, and polysaccharides, whose applications go from pharmaceutical to agricultural industries. Recently, the research focus has been directed to the biopolymer-producing ability of both micro- and macroalgae, as they can be rather varied and useful to many applications. However, this is still an ongoing research field, and new data are frequently added in the literature, notably on biomass processing, which can be done with the intent of use into dyes, bioplastics, paints, and even as biochar in solid fuel cells. Microalgae-based biopolymers can be used in a wide range of products, nevertheless, the resulting process efficiency and yields depend on the extraction process utilized, as well as on the microalgae species used and the culture conditions. Furthermore, the polymer extraction can be done directly with common solvents at atmospheric pressure or with other fluids, such as supercritical CO2 or subcritical solvents, and assisted by specific treatments, e.g., ultrasound and microwave. The residual biomass can still be used to produce other less valuable products, such as feedstock, and energy via combustion. In this sense, the present work aims to provide a state-of-the-art review on microalgae biopolymers. Issues related to the efficiency of current treatment methods, industrial applications, and environmental performance are presented and discussed. Besides, the perspectives in this area of knowledge are also a contribution of the present work, the extent to which scientific research is still under development

    Detrended Fluctuation Analysis of Systolic Blood Pressure Control Loop

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    We use detrended fluctuation analysis (DFA) to study the dynamics of blood pressure oscillations and its feedback control in rats by analyzing systolic pressure time series before and after a surgical procedure that interrupts its control loop. We found, for each situation, a crossover between two scaling regions characterized by exponents that reflect the nature of the feedback control and its range of operation. In addition, we found evidences of adaptation in the dynamics of blood pressure regulation a few days after surgical disruption of its main feedback circuit. Based on the paradigm of antagonistic, bipartite (vagal and sympathetic) action of the central nerve system, we propose a simple model for pressure homeostasis as the balance between two nonlinear opposing forces, successfully reproducing the crossover observed in the DFA of actual pressure signals

    Chiral 2pi exchange at order four and peripheral NN scattering

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    We calculate the impact of the complete set of two-pion exchange contributions at chiral order four (also known as next-to-next-to-next-to-leading order, N3LO) on peripheral partial waves of nucleon-nucleon scattering. Our calculations are based upon the analytical studies by Kaiser. It turns out that the contribution of order four is substantially smaller than the one of order three, indicating convergence of the chiral expansion. We compare the prediction from chiral pion-exchange with the corresponding one from conventional meson-theory as represented by the Bonn Full Model and find, in general, good agreement. Our calculations provide a sound basis for investigating the issue whether the low-energy constants determined from pi-N lead to reasonable predictions for NN.Comment: 22 pages RevTex including 11 figure

    Recent results in relativistic heavy ion collisions: from ``a new state of matter'' to "the perfect fluid"

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    Experimental Physics with Relativistic Heavy Ions dates from 1992 when a beam of 197Au of energy greater than 10A GeV/c first became available at the Alternating Gradient Synchrotron (AGS) at Brookhaven National Laboratory (BNL) soon followed in 1994 by a 208Pb beam of 158A GeV/c at the Super Proton Synchrotron (SPS) at CERN (European Center for Nuclear Research). Previous pioneering measurements at the Berkeley Bevalac in the late 1970's and early 1980's were at much lower bombarding energies (~ 1 A GeV/c) where nuclear breakup rather than particle production is the dominant inelastic process in A+A collisions. More recently, starting in 2000, the Relativistic Heavy Ion Collider (RHIC) at BNL has produced head-on collisions of two 100A GeV beams of fully stripped Au ions, corresponding to nucleon-nucleon center-of-mass energy, sqrt(sNN)=200 GeV, total c.m. energy 200A GeV. The objective of this research program is to produce nuclear matter with extreme density and temperature, possibly resulting in a state of matter where the quarks and gluons normally confined inside individual nucleons (r < 1 fm) are free to act over distances an order of magnitude larger. Progress from the period 1992 to the present will be reviewed, with reference to previous results from light ion and proton-proton collisions where appropriate. Emphasis will be placed on the measurements which formed the basis for the announcements by the two major laboratories: "A new state of matter", by CERN on Feb 10, 2000 and "The perfect fluid", by BNL on April 19, 2005.Comment: 62 pages, 39 figures. Review article published in Reports on Progress in Physics on June 23, 2006. In this published version, mistakes, typographical errors, and citations have been corrected and a subsection has been adde
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