W Pair Production at the LHC - I. Virtual O(alpha_s^2) Corrections in the High Energy Limit

We present the result for the two-loop and the one-loop squared virtual QCD corrections to the W boson pair production in the quark-anti-quark-annihilation channel in the limit where all kinematical invariants are large compared to the mass of the W boson. The infrared pole structure is in agreement with the prediction of Catani's general formalism for the singularities of two loop amplitudes.Comment: 22 pages, 1 figure, references added, typos corrected, final version as publishe

Cortante-fricción de los hormigones reciclados

The aim of this research was to determine the behavior of recycled concrete in response to the phenomenon of shear transfer. To perform it, a conventional control concrete and a concrete with 50% recycled coarse aggregate were designed. An additional goal was to shed light on how this behavior is modified with a pozzolanic addition, silica fume. Therefore, two types of concrete were designed, a conventional and a recycled concrete, both made with 8% of silica fume. In conclusion, a reduction of shear friction capacity was observed in recycled concretes, considerably higher in the case of the specimen without reinforcement. The addition of silica fume improved the behavior of recycled concretes. The results obtained were compared with the formulations of the different authors. In all cases, these were found to be conservative. However, the safety margins offered by recycled concretes are lower than those obtained with conventional concretes.En esta investigación se estudió el comportamiento de los hormigones reciclados frente al fenómeno de transmisión de cortante. Para ello se diseñó un hormigón convencional de control y un hormigón con el 50% del árido grueso reciclado. Adicionalmente, para determinar cómo este comportamiento se ve modificado con la incorporación de una adición puzolánica (humo de sílice), se procedió al diseño de un hormigón convencional y su correspondiente reciclado con un 8% de humo de sílice. Los resultados indicaron una disminución de la capacidad frente a este fenómeno en los hormigones reciclados, más acusada en ausencia de armadura pasante. La adición de humo de sílice mejora el comportamiento de este material. Los resultados experimentales obtenidos se compararon con formulaciones teóricas de diversos autores, concluyéndose que éstas son, en todos los casos, conservadoras, aunque reducen el margen de seguridad en los hormigones reciclados

Detection and partial molecular characterization of isolates of Grapevine leafroll-associated virus 4 and Grapevine rupestris vein feathering virus.

Resumo apresentado de número 371-2

Clinical importance of circulating immune complexes in human acute lymphoblastic leukemia

A total of 122 sera from acute lymphoblastic leukemia (ALL) patients were analyzed for circulating immune complexes (CIC) by two methods: the 125I-C1q binding assay and the polyethylene glycol precipitation test (PEG). The results were correlated with induction, remission and relapse stages of the disease. Using the first method the levels of CIC in induction were 15.18±9.15, with 19/29 positive cases (65.50%), P<0.001 compared with controls. In the remission phase the levels were 9.02±5.62, 11/45 (24.49%) nonsignificant P value, and in relapse they were 16.14±11.17 28/48 (58.33%) P<0.001. The PEG precipitation test results were: 0.33±0.10, 8/22 (36.36%); 0.24±0.11, 10/48 (20.83%) and 0.28±0.10, 6/28 (21.42%), respectively. Thus the values of CIC as measured by PEG in the three clinical of phases ALL did not differ significantly from controls. This contrasts with results obtained by the radioiodinated C1q binding assay, where the incidence of positive values was significantly higher in induction and in relapse and lower in the remission phase. These observations were extended in sequential vertical studies performed in a group of patients. These results suggest that raised CIC detected by the 125I-C1q method may reflect a progressive state in ALL and that quantitation of these immune complexes may provide an adequate biochemical marker for prognosis.Facultad de Ciencias Médica

Variáveis agronômicas e variabilidade viral entre videiras sintomáticas e assintomáticas para viroses.

Os objetivos deste trabalho foram avaliar variáveis agronômicas em videiras com e sem sintomas de virose e caracterizar isolados virais destas plantas

Investigation of dielectric anomalies at cryogenic temperatures in the (1-x)[Pb(Mg1/3 Nb2/3)O3]-xPbTiO3 system

Complex electrical permittivity measurements in (1-x)[Pb(Mg1/3 Nb2/3)O3]-xPbTiO3 ceramics for 0.10 x 0.40 were performed in the frequency and temperature range from 1 kHz to 100 kHz and from 15 to 600 K, respectively. Unexpected dielectric anomalies, which were frequency dependent, were found at cryogenic temperatures. It was verified that this dielectric behavior is always observed, independently of whether the composition presents a "normal" ferroelectric or a relaxor characteristic. The results were analyzed within the framework of two current models found in the literature. It was concluded that none of the proposed mechanisms uniquely satisfies the experimental results in the composition range investigated here.Comment: 9 pages, 7 figures - Accepted for publication in the Applied Physics Lette