Spectroscopy of 26^{26}F

The structure of the weakly-bound $^{26}_{\;\;9}$F$_{17}$ odd-odd nucleus, produced from $^{27,28}$Na nuclei, has been investigated at GANIL by means of the in-beam $\gamma$-ray spectroscopy technique. A single $\gamma$-line is observed at 657(7) keV in $^{26}_{9}$F which has been ascribed to the decay of the excited J=$2^+$ state to the J=1$^+$ ground state. The possible presence of intruder negative parity states in $^{26}$F is also discussed.Comment: 3 pages, 1 figure, accepted for publication in Physical Review

26Mg target for nuclear astrophysics measurements

Two nuclear reactions of astrophysical interest, 26Mg(3He,d)27Al and 26Mg(d,p)27Mg, were measured for extraction of the Asymptotic Normalization Coefficients. Investigation of the target composition is presented, as well as the effects that showed up during analysis of the in-beam data obtained on CANAM accelerators in the Nuclear Physics Institute of the Czech Academy of Sciences (NPI CAS)

The astrophysical S-factor of the direct 18O(p, γ)19F capture by the ANC method

We attempted to determine the astrophysical S-factor of the direct part of the 18 O(p, γ ) 19 F capture by the indirect method of asymptotic normalization coefficients (ANC). We measured the differential cross section of the transfer reaction 18 O( 3 He, d) 19 F at a 3 He energy of 24.6 MeV. The measurement was realized on the cyclotron of the NPI in Řež, Czech Republic, with the gas target consisting of the high purity 18 O (99.9 %). The reaction products were measured by eight ∆E-E telescopes composed from thin and thick silicon surface-barrier detectors. The parameters of the optical model for the input channel were deduced by means of the code ECIS and the analysis of transfer reactions to 12 levels of the 19 F nucleus up to 8.014 MeV was made by the code FRESCO. The deduced ANCs were then used to specify the direct contribution to the 18 O(p, γ ) 19 F capture process and were compared with the mutually different results of two works

Identificación de Xilanasas GH10 en las cepas 2 y Mz5 de Pseudobutyrivibrio xylanivorans

El rumen contiene una población bacteriana encargada de la degradación del xilano, el principal componente de la hemicelulosa presente en la pared celular vegetal de los forrajes que consumen las cabras. Las bacterias del rumen, principalmente los géneros Butyrivibrio y Pseudobutyrivibrio, sintetizan una gama de enzimas xilanolíticas para la digestión eficaz de los componentes de la pared celular. Los genes que codifican para xilanasas pertenecientes a la familia glicosil hidrolasa 11 (GH11) y la actividad xilanasa asociada han sido identificados en la cepa tipo (Mz5) de P. xylanivorans. Por el contrario, poco se sabe acerca de la diversidad y distribución de los genes xilanasa GH10 en otras cepas de Pseudobutyrivibrio. // El objetivo del presente estudio fue identificar genes xilanasa GH10 en P. ruminis 153, P. xylanivorans 2 y Mz5. Además, se evaluó la degradación y utilización de xilano por las cepas aisladas del rumen de cabras Criollas. Se identificó un gen xilanasa (xynAPx) en P. xylanivorans 2 y otro gen xilanasa diferente (xynBMz5) en P. xylanivorans Mz5. Estos genes se relacionaron con enzimas presentes en especies de Butyrivibrio. P. xylanivorans 2 fue capaz de utilizar hasta el 53% de las pentosas totales presentes en el xilano de la madera de abedul (BWX) y utilizar hasta el 62% del BWX. // La presencia de genes xilanasas GH10 y la actividad xilanasa reportada en P. xylanivorans 2, permitió concluir el rol funcional de esta cepa en la degradación de la hemicelulosa presente en forrajes con abundante contenido de fibra vegetal. Esta característica podría ser uno de los mecanismos de adaptación de los caprinos Criollos para el aprovechamiento de forrajes de baja calidad nutricional que consumen en el campo natural

Symbolic Computation via Program Transformation

Symbolic computation is an important approach in automated program analysis. Most state-of-the-art tools perform symbolic computation as interpreters and directly maintain symbolic data. In this paper, we show that it is feasible, and in fact practical, to use a compiler-based strategy instead. Using compiler tooling, we propose and implement a transformation which takes a standard program and outputs a program that performs semantically equivalent, but partially symbolic, computation. The transformed program maintains symbolic values internally and operates directly on them hence the program can be processed by a tool without support for symbolic manipulation. The main motivation for the transformation is in symbolic verification, but there are many other possible use-cases, including test generation and concolic testing. Moreover using the transformation simplifies tools, since the symbolic computation is handled by the program directly. We have implemented the transformation at the level of LLVM bitcode. The paper includes an experimental evaluation, based on an explicit-state software model checker as a verification backend

Adaptive structure tensors and their applications

The structure tensor, also known as second moment matrix or Förstner interest operator, is a very popular tool in image processing. Its purpose is the estimation of orientation and the local analysis of structure in general. It is based on the integration of data from a local neighborhood. Normally, this neighborhood is defined by a Gaussian window function and the structure tensor is computed by the weighted sum within this window. Some recently proposed methods, however, adapt the computation of the structure tensor to the image data. There are several ways how to do that. This article wants to give an overview of the different approaches, whereas the focus lies on the methods based on robust statistics and nonlinear diffusion. Furthermore, the dataadaptive structure tensors are evaluated in some applications. Here the main focus lies on optic flow estimation, but also texture analysis and corner detection are considered

Análisis de la diversidad bacteriana del rumen de cabras Criollas alimentadas con dos dietas diferentes mediante PCR-DGGE y q-PCR

La compleja microbiota simbiótica del rumen es responsable de la degradación de la fibra vegetal, una capacidad que los tejidos del animal hospedador han perdido evolutivamente. Poco se conoce acerca de las características de fermentación y las poblaciones bacterianas del rumen de las cabras Criollas. Los recientes avances en técnicas de biología molecular permiten el análisis de tales bacterias sin la necesidad de cultivarlas, y la identificación de esta manera de muchas bacterias funcionales, no cultivadas, como nuevos objetivos de investigación básica y aplicada. // Existe un creciente interés en comprender los mecanismos a partir de los cuales las taxas bacterianas muestran respuestas uniformes frente a diferentes estímulos ambientales. Las técnicas de PCR-DGGE y qPCR fueron asociadas en una aproximación en dos pasos, para determinar tanto la abundancia como la diversidad de las comunidades bacterias que habitan el rumen de cabras Criollas, alimentadas con dos dietas diferentes: heno de alfalfa y maíz (HA/M) y forrajeras nativas (FN)