Caracterización morfológica de los problemas de locomoción en pollos de engorde, 2. Discondroplasia de la tibia.

El presente estudio se llevó a cabo con el objeto de caracterizar macro y microscópicamente la morfología de las principales condiciones patológicas que se manifiestan con problemas de locomoción en pollos de engorde. Se evaluaron 133 animales, en una granja comercial localizada en el municipio de Sasaima (1200 m.s.n.m., 28 grados centígrados) con una población de 35 mil pollos de la raza Arbor-Acres. Las observaciones se realizaron durante el ciclo de producción de 7 semanas mediante una visita semanal en las cuales se seleccionaron para el estudio los pollos que desde el punto de vista clínico presentaron anomalías estructurales del aparato locomotor, los que presentaban movimientos anormales de desplazamiento y aquellos que sin presentar ninguna alteración anatómica aparente, tenian posiciones defectuosas. De los animales retirados con las características anteriormente mencionadas se tomó la fracción muestral para los estudios clinicopatológicos. En cada una de las observaciones se tomaron 2 animales clínicamente sanos para efecto de comparación. Clínicamente, los animales con problemas de locomoción se caracterizaron por su menor tamaño dentro del lote y claudicaciones ocasionadas por desviación de las extremidades en 40 animales, tumefacción de las articulaciones de 30 animales, posiciciones anormales en 30 y parálisis en 20 animales. Los hallazgos microscópicos más sobresalientes consistieron en disminución de longitud del tibiotarso en 86 pollos, engrozamiento articular en 34 animales, engrosamiento e irregularidad de la línea epifisiaria en 12, to rción del tibiotarso en 15 animales y proyecciones cartilaginosas en forma de cuña típica de discondroplasia de la tibia (DT) en 3 animales.;La evaluación microscópica de los tibiotarsos permitió demostrar que además de los 3 pollos con franca discondroplasia, 12 presentaron lesiones que de acuerdo con el presente estudio y con otros autores se debe considerar como casos asintomáticos o prediscondroplásicos. La discondroplasia de la tibia se caracteriza por la presencia de cuñas de cartílago avascular que penetra hacia la diafisis del tibiotarso, aunque la lesión puede encontrarse en otros huesos como el femur y el húmero. Se plantea la necesidad de adelantar estudios de asociación causa-efecto, destacando la correlación que podria existir entre contaminación alimenticia por micotoxinas y la presentación de la enfermedadAvicultur

Approximate Deadline-Scheduling with Precedence Constraints

We consider the classic problem of scheduling a set of n jobs non-preemptively on a single machine. Each job j has non-negative processing time, weight, and deadline, and a feasible schedule needs to be consistent with chain-like precedence constraints. The goal is to compute a feasible schedule that minimizes the sum of penalties of late jobs. Lenstra and Rinnoy Kan [Annals of Disc. Math., 1977] in their seminal work introduced this problem and showed that it is strongly NP-hard, even when all processing times and weights are 1. We study the approximability of the problem and our main result is an O(log k)-approximation algorithm for instances with k distinct job deadlines

Remote system for detection of low-levels of methane based on photonic crystal fibres and wavelength modulation spectroscopy

In this work we described an optical fibre sensing system for detecting low levels of methane. The properties of hollow-core photonic crystal fibres are explored to have a sensing head with favourable characteristics for gas sensing, particularly in what concerns intrinsic readout sensitivity and gas diffusion time in the sensing structure. The sensor interrogation was performed applying the Wavelength Modulation Spectroscopy technique, and a portable measurement unit was developed with performance suitable for remote detection of low levels of methane. This portable system has the capacity to simultaneously interrogate four remote photonic crystal fibre sensing heads. Copyright © 2009 J. P. Carvalho et al

Development of poly (lactic-co-glycolic acid)/bioglass fibers using an electrospinning technique.

This work establishes experimental conditions for the synthesis of polymeric fibers using the electrospinning technique, modifying some operational parameters such as drum collector rotation speed and applied voltage were modified. The samples were obtained from a copolymer of poly(lactic-co-glycolic acid) (PLGA), with a molecular weight of approximately 220,000 g/mol, dissolved in a dimethyl sulfoxide/dichloromethane (3:1 v/v) solution. With the aim of developing scaffolds for bone tissue engineering, we added a calcium phosphate glass based on 44.5Ca0-44.5P2O5-11Na2O to the fibrous PLGA structures. The preliminary characterization of these PLGA structures with and without the addition of biodegradable glass was performed using SEM analysis. We found the formation of aligned and homogeneous fibers with an average diameter of 5.2 ± 2.1 µm when using the 800 rpm - 8cm - 9 kV parameters. In addition, the incorporation of 1 wt% of previously silanized calcium phosphate particles substantially altered the fiber morphology and porosity. However, a substantial increase in the bioactivity of the composite was observed in contrast with the unmodified PLGA

INFECCION FILARIAL DE APROCTELLA STODDARDI CRAM, 1931 (NEMATODA: ONCHOCERCIDAE) EN PASSERIFORMES DE AREAS PERIURBANAS, ESTADO DE PARÁ. BRASIL

Reports of filarial nematodes in wild birds are scarce in South America, particularly in the Amazon region. We analyzed the organs in the thoracic and abdominal cavities of 34 wild birds belonging to 12 different species of the order Passeriformes in the Periurban areas of Para State. Adult filariae was observed in 3/34 (9%) birds, located in the abdominal cavity of hosts. The morphological and morphometric characteristics of the filarial nematodes were consistent with the taxonomic classification of Aproctella stoddardi Cram, 1931, making this the first report of this species in the Amazon region in northern Brazil. Due to the observed migration of other genera of filariae, Aproctella Cram, 1931 may have the ability to infection at other sites, such as the liver, heart, lung, and brain. In addition, it is necessary to expand the records of the presence of filariae in birds of the region to elucidate the factors that influence this infection.Reportes de nematodos filarias en aves silvestres son escasos en América del Sur, principalmente en la región amazónica. Fueron analizados los órganos de las cavidades torácica y abdominal de 34 aves silvestres pertenecientes a 12 especies diferentes de aves Passeriformes en áreas periurbanas del Estado de Pará. Filarias adultas fueron observadas en 3/34 (9%) aves, localizadas en la cavidad abdominal de los huéspedes Las características morfológicas y morfométricas de los nematodos fueron compatibles con la clasificación taxonómica de Aproctella stoddardi Cram, 1931, siendo este el primer relato de esta especie en la amazónica en el norte de Brasil. Debido a la migración observada de otros géneros de filarias, Aproctella Cram, 1931 puede tener la capacidad de infección en otros sitios, como hígado, corazón, pulmón y cerebro. Además, es necesario ampliar los registros de filarias en aves de la región para elucidar los factores que influencian esta infección

The measurement programme at the neutron time-of-flight facility n-TOF at CERN

Neutron-induced reaction cross sections are important for a wide variety of research fields ranging from the study of nuclear level densities, nucleosynthesis to applications of nuclear technology like design, and criticality and safety assessment of existing and future nuclear reactors, radiation dosimetry, medical applications, nuclear waste transmutation, accelerator-driven systems and fuel cycle investigations. Simulations and calculations of nuclear technology applications largely rely on evaluated nuclear data libraries. The evaluations in these libraries are based both on experimental data and theoretical models. CERN's neutron time-of-flight facility n-TOF has produced a considerable amount of experimental data since it has become fully operational with the start of its scientific measurement programme in 2001. While for a long period a single measurement station (EAR1) located at 185 m from the neutron production target was available, the construction of a second beam line at 20 m (EAR2) in 2014 has substantially increased the measurement capabilities of the facility. An outline of the experimental nuclear data activities at n-TOF will be presented

Vidrios biomédicos y vitrocerámicas como sustitutos de los tejidos óseos

Nowadays, an important research topic related with medical devices are the materials designed as bone tissues substitutes. Hard tissues have a great capacity of self-regeneration but in front of traumatic or pathologic critical bone defects it is necessary the use of bone substitutes or templates as temporal or permanent grafts. Glasses or glass-ceramics are osteoconductive, osteoinductive and biocompatible materials. In addition, they have the ability to link directly to the living bone tissues without any interface (bioactivity). Also, it has been reported that bioglasses favor the angiogenesis process and the cellular adhesion, proliferation and differentiation necessary features for bone tissue engineering scaffolds. This work refers generalities of the bioactive glasses and glass-ceramics compositions, manufacture processes, properties, advantages, disadvantages as well as the main clinical applications and new developments for tissue engineering

Studies on the mineral nutrition of the rice plant: IX. time course on the uptake of macronutrients by the variety IAC-47

Rice plants, variety IAC-47, were grown in the nº 2 nutrient solution of HOAGLAND & ARNON (1950) until the end of the life cycle. Plants were sampled at well defined physiological periods for analyses. It was verified that trends for levvelling off occurred in the case of accumulation of N, K and Ca. Translocation from leaves to grain was observed with respect to N, P and K. Maximum rates of uptake of all elements took place from 50 to 100 days after germination.Foram estudadas, em condições controladas, a acumulação de matéria seca e a de macronutrientes na variedade de arroz IAC-47. Ambos os processos em geral são descritos por sigmóides típicas; picos para os valores totais de produção de matéria seca e de acumulação de elementos entre: 100 e 140 dias depois da germinação