200 research outputs found
Post-harvest quality of fresh-marketed tomatoes as a function of harvest periods
Losses on tomato business chain start at harvest, a two-months period. At the beginning of the harvest, fruits concentrate at the basal part of the plant, then in the middle, and finally at the top, and undergo changes in diameter and maturity indexes as harvest progresses. The aim of this work was to evaluate the impact of handling at three different periods: (I) 15 days, (II) 30 days, and (III) 45 days after the beginning of harvest. Tomatoes were ordinarily grown and harvested in to bamboo baskets, and transferred to plastics boxes. Fruits were classified according to ripening stage and diameter, and evaluated for mechanical damage and external defects caused by harvesting procedures. The time required for the harvest operation was measured; damage to fruits (%) and weight loss (%), caused either in the field and/or during the harvesting process, were taken into consideration and related to the final quality of fruit after storage for 21 days. The same methodology was used all through the production and harvest cycle. The highest % fruit damage occurred during period II, a longer harvest time than the other two periods. Fruits not submitted to handling showed lower weight loss than handled fruits. Fruits harvested in period II and stored for 21 days showed higher losses due to mechanical injury
Three-dimensional black holes, gravitational solitons, kinks and wormholes for BHT massive gravity
The theory of massive gravity in three dimensions recently proposed by
Bergshoeff, Hohm and Townsend (BHT) is considered. At the special case when the
theory admits a unique maximally symmetric solution, a conformally flat space
that contains black holes and gravitational solitons for any value of the
cosmological constant is found. For negative cosmological constant, the black
hole is characterized in terms of the mass and the "gravitational hair"
parameter, providing a lower bound for the mass. For negative mass parameter,
the black hole acquires an inner horizon, and the entropy vanishes at the
extremal case. Gravitational solitons and kinks, being regular everywhere, are
obtained from a double Wick rotation of the black hole. A wormhole solution in
vacuum that interpolates between two static universes of negative spatial
curvature is obtained as a limiting case of the gravitational soliton with a
suitable identification. The black hole and the gravitational soliton fit
within a set of relaxed asymptotically AdS conditions as compared with the ones
of Brown and Henneaux. In the case of positive cosmological constant the black
hole possesses an event and a cosmological horizon, whose mass is bounded from
above. Remarkably, the temperatures of the event and the cosmological horizons
coincide, and at the extremal case one obtains the analogue of the Nariai
solution, . A gravitational soliton is also obtained
through a double Wick rotation of the black hole. The Euclidean continuation of
these solutions describes instantons with vanishing Euclidean action. For
vanishing cosmological constant the black hole and the gravitational soliton
are asymptotically locally flat spacetimes. The rotating solutions can be
obtained by boosting the previous ones in the plane.Comment: Talk given at the "Workshop on Gravity in Three Dimensions," 14-24
April 2009, ESI, Vienna. 30 pages, 6 figures. V2: minor changes and section 6
slightly improved. Last version for JHE
Analytical results for coupled map lattices with long-range interactions
We obtain exact analytical results for lattices of maps with couplings that
decay with distance as . We analyze the effect of the coupling
range on the system dynamics through the Lyapunov spectrum. For lattices whose
elements are piecewise linear maps, we get an algebraic expression for the
Lyapunov spectrum. When the local dynamics is given by a nonlinear map, the
Lyapunov spectrum for a completely synchronized state is analytically obtained.
The critical lines characterizing the synchronization transition are determined
from the expression for the largest transversal Lyapunov exponent. In
particular, it is shown that in the thermodynamical limit, such transition is
only possible for sufficiently long-range interactions, namely, for , where is the lattice dimension.Comment: 4 pages, 2 figures, corrections included. Phys. Rev. E 68, 045202(R)
(2003); correction in pres
Extracellular Matrix Degradation Products and Low-Oxygen Conditions Enhance the Regenerative Potential of Perivascular Stem Cells
Tissue and organ injury results in alterations of the local microenvironment, including the reduction in oxygen concentration and degradation of the extracellular matrix (ECM). The response of perivascular stem cells to these microenvironment changes are of particular interest because of their wide distribution throughout the body and their potential involvement in tissue and organ response to injury. The chemotactic, mitogenic, and phenotypic responses of this stem cell population were evaluated in response to a combination of decreased oxygen concentration and the presence of ECM degradation products. Culture in low-oxygen conditions resulted in increased proliferation and migration of the cells and increased activation of the ERK signaling pathway and associated integrins without a change in cell surface marker phenotype. The addition of ECM degradation products were additive to these processes. Reactive oxygen species within the cells were increased in association with the mitogenic and chemotactic responses. The increased proliferation and chemotactic properties of this stem cell population without any changes in phenotype and differentiation potential has important implications for both in vitro cell expansion and for in vivo behavior of these cells at the site of injury
Estrategia de cruzamientos para el mejoramiento de pollos camperos. Un proyecto colaborativo INTA-Universidad
Campero chicken is a bird destined to production systems alternative to the industrial one. Campero INTA is a two-way cross between synthetic populations generated by INTA in Pergamino. These populations have remained closed and with a low effective size with the consequent detrimental effect associated with inbreeding depression. To have a dual-purpose population with adequate meat and egg production levels and rusticity to be used in semi-intensive systems that preserve animal welfare, a survey program of the available genetic resource was implemented and a crossbreeding plan to produce a terminal three-way hybrid was designed. The sequence included the evaluation of five maternal synthetic populations (A, E, DE, ES and CE), the selection of two of them (ES and A), their characterization in two-way reciprocal crosses [(ESxA) and (AxES)], the choice of the alternative (ESxA) as female parent and its crossing by roosters of the improved paternal line AH’ to obtain the Campero Casilda chicken as the final product. The evaluation of their growth pattern, body conformation, conversion ratio and productive characters at slaughter indicate that both males and females satisfied the requirements as birds destined for meat production established in the respective protocol. The evaluation of productive characters at sexual maturity, dynamic pattern of egg weight gain and laying curves allowed to qualify the females as layers.El pollo campero es un ave destinado a sistemas productivos alternativos al industrial. Campero INTA es un cruzamiento simple entre poblaciones sintéticas generadas por INTA en Pergamino. Estas poblaciones se han mantenido cerradas y con bajo tamaño efectivo con el consiguiente efecto detrimental asociado a fenómenos de depresión endogámica. Con el objetivo de disponer de una población doble propósito con adecuados niveles productivos de carne y huevos y de rusticidad para ser utilizada en sistemas semi-intensivos que preservan el bienestar animal, se implementó un programa de relevamiento del recurso genético disponible y se diseñó un plan de cruzamientos dirigido a la producción de un híbrido terminal de tres vías. La secuencia incluyó la evaluación de cinco poblaciones sintéticas maternas (A, E, DE, ES y CE), la selección de dos de ellas (ES y A), su caracterización en cruzamientos simples recíprocos [(ESxA) y (AxES)], la elección de la alternativa (ESxA) como progenitor femenino y su cruzamiento por gallos de la estirpe paterna mejorada AH’ para la obtención como producto final del pollo Campero Casilda. La evaluación de su patrón de crecimiento, conformación corporal, relación de conversión y caracteres productivos a la faena indican que tanto los machos como las hembras cumplen, como aves destinadas a la producción de carne, con las exigencias establecidas en el protocolo respectivo. La evaluación de los caracteres productivos a la madurez sexual, el patrón dinámico de aumento de peso del huevo y las curvas de postura califican a las hembras para su utilización como ponedoras.Estación Experimental Agropecuaria PergaminoFil: Canet, Zulma Edith. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Sección Avicultura; ArgentinaFil: Canet, Zulma Edith. Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias. Cátedra de genética; Argentina.Fil: Dottavio, Ana María. Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias. Cátedra de genética; ArgentinaFil: Romera, Bernardo Martín. Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias. Cátedra de Genética; ArgentinaFil: Romera, Bernardo Martín. Programa Estratégico de Formación de Recursos Humanos en Investigación y Desarrollo (PERHID). Becario; ArgentinaFil: Librera, José Ernesto. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Sección Avicultura; Argentina.Fil: Librera, José Ernesto Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias. Cátedra de Genética; ArgentinaFil: Advínculo, S.A. Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias. Cátedra de Genética; ArgentinaFil: Martines, Araceli. Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias. Cátedra de Genética; ArgentinaFil: Di Masso, Ricardo José. Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias Cátedra de genética; Argentina
Treatment of a forelimb fracture and rehabilitation of a free-ranging Iberian Wolf (Canis lupus signatus)
Evaluation of two experimental three-way hybrids of free-range chickens under two feeding managements
El pollo campero es un ave con menor velocidad de crecimiento y mayor rusticidad que el pollo parrillero industrial, y está destinado a sistemas de producción semi-intensiva que contemplan aspectos vinculados con el bienestar animal. El esquema tradicional de alimentación de estas aves incluye la utilización de tres tipos de alimento –“Iniciador”, “Crecimiento” y “Terminador”- formulados específicamente para cada una de las etapas. Dado que es complejo manejar tres tipos de alimento en explotaciones pequeñas, los productores se plantean la posibilidad de manejar sólo dos: “Iniciador” y “Terminador”. El objetivo de este trabajo fue caracterizar el comportamiento productivo y la calidad física de la carne de machos de dos cruzamientos experimentales de tres vías de pollo campero -Campero Casilda y Campero Pergamino- como alternativas frente al cruzamiento simple Campero INTA, bajo dos manejos
de alimentación (a) tradicional de tres raciones y tres dietas y (b) alternativo con sólo dos raciones (iniciador y terminador) y cinco
dietas. Los dos cruzamientos experimentales se desempeñaron de manera equivalente en relación con la mayoría de las variables
analizadas y presentaron mayor peso que Campero INTA lo que los transforma en opciones válidas para sistemas de avicultura
alternativa a la industrial. La ausencia de modificaciones de trascendencia productiva al reemplazar el alimento crecimiento por combinaciones de iniciador y terminador indica la posibilidad de obviar su inclusión en el esquema de alimentación, simplificando así la producción de este tipo de aves.Campero chicken is a type of meat producing bird with a lower body weight gain and a greater rusticity than their industrial broilers counterparts, intended for semi-intensive production systems that prioritizes aspects related to animal welfare. The traditional feeding scheme includes the use of three types of diets specially formulated for this purpose (Starter, Grower and Finisher). Taking into account the complexity of managing three types of food in small farms, the producers consider the possibility of managing only two: “Starter” and “Finisher”. The aim of this work was to characterize the productive behavior and the physical quality of the meat, of males of two threeway experimental hybrids of free range chickens -Campero Casilda y Campero Pergamino- as alternatives to the twoway
cross Campero INTA. Both experimental crosses were evaluated under two feeding regimens (a) traditional, with three diets (Starter, Grower and Finisher) and three rations, and (b) alternative, with only two diets (Starter and Finisher) combined in five rations. The experimental crosses performed in an equivalent manner for almost all traits, being both heavier than Campero INTA, which transforms them into valid options for poultry systems alternative to the industrial one. The lack of meaningful productive differences when Grower feed was replaced by three Starter + Finisher combinations, indicates the feasibility of avoiding its inclusion in the feeding scheme, thus simplifying the production of this type of free-range birds.EEA PergaminoFil: Dottavio, Ana María. Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias. Cátedra de Genética; ArgentinaFil: Dottavio, Ana María. Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias. Carrera del Investigador Científico; ArgentinaFil: Fernández, R. Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias. Cátedra de Economía Agraria y Administración Rural; ArgentinaFil: Romera, Bernardo Martín. Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias. Cátedra de Genética; ArgentinaFil: Advínculo, S.A. Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias. Cátedra de Genética; ArgentinaFil: Martines, Araceli. Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias. Cátedra de Genética; ArgentinaFil: Librera, José Ernesto. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino.; ArgentinaFil: Librera, José Ernesto. Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias. Cátedra de Genética; ArgentinaFil: Canet, Zulma Edith. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino; ArgentinaFil: Canet, Zulma Edith. Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias. Cátedra de Genética; ArgentinaFil: Di Masso, Ricardo José. Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias. Cátedra de Genética; ArgentinaFil: Di Masso, Ricardo José. Universidad Nacional de Rosario. Facultad de Ciencias Veterinarias. Carrera del Investigador Científico; Argentin
Neurological disorder associated with pestivirus infection in sheep in Rio Grande do Sul, Brazil
The state of the Martian climate
60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes
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