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A study of the antioxidant capacity of oak wood used in wine ageing and the correlation with polyphenol composition
The antioxidant capacity of oak wood used in the ageing of wine was studied by four different methods: measurement of scavenging capacity against a given radical (ABTS, DPPH), oxygen radical absorbance capacity (ORAC) and the ferric reducing antioxidant power (FRAP). Although, the four methods tested gave comparable results for the antioxidant capacity measured in oak wood extracts, the ORAC method gave results with some differences from the other methods. Non-toasted oak wood samples displayed more antioxidant power than toasted ones due to differences in the polyphenol compositon. A correlation analysis revealed that ellagitannins were the compounds mainly responsible for the antioxidant capacity of oak wood. Some phenolic acids, mainly gallic acid, also showed a significant correlation with antioxidant capacity
Stimulus specificity in the acquisition and extinction of conditioned taste aversion
Vogel, E.H. Universidad de Talca, Escuela de Psicología, Casilla N° 747, Talca, Chile.An experiment evaluated whether the acquisition and extinction of conditioned taste aversion in the rat is stimulus-specific by testing the degree of response transfer between sweet and salty tastes. Animals in the paired-same and paired-different groups received a presentation of a gustatory CS and a cyclophosphamide injection US. Nonconditioned control groups received unpaired CS /US presentations or the CS followed by a vehicle injection. Taste avoidance was evaluated in three nonreinforced test sessions. In the paired-same, unpaired and vehicle groups, all test sessions were conducted with the same flavor as originally used in training, whereas the paired-different group was tested with a novel flavor on the first and second sessions and with the originally trained flavor in last session. Stimulus specific acquisition was apparent in the first test session, when the animals in the group paired-same exhibited lower fluid intake than the other three groups. Evidence of specificity of extinction was apparent in the last test session, when animals in the group paired-different exhibited lower fluid intake than the other three groups. These results provide further evidence of stimulus specificity in acquisition and extinction of conditioned taste aversion, supporting the associative interpretation of these phenomen
A calculation methodology for the determination of the dynamic alongwind response of tall structures under wind action
La optimización de los métodos de cálculo, junto al avance de la tecnología en la construcción de estructuras civiles, permiten actualmente diseñar y construir estructuras cada vez más livianas, de baja rigidez y amortiguamiento, transformándolas en elementos altamente sensibles a los efectos dinámicos inducidos por la acción del viento. El objetivo de este trabajo es el de describir y aplicar una metodología sencilla de cálculo que permita la determinación de la respuesta dinámica longitudinal en el dominio del tiempo de estructuras altas sometidas a la acción del viento. El campo de velocidad de viento se reproduce mediante series de velocidad que incluyen la función de coherencia, para luego transformarlas en fuerzas nodales fluctuantes utilizando el modelo de carga cuasi-estático. Para incluir el efecto de promediado imperfecto asociado a los nodos discretizados, se incorpora además la función de admitancia aerodinámica. Mediante la metodología propuesta se analizan dos estructuras ampliamente estudiadas por otros autores, las cuales consisten en una torre de acero y el CAARC Standard Tall Building. Los resultados así obtenidos presentan concordancia con los reportados por la bibliografía de referencia.The optimization of computing methods along with the advance of construction technology of civil structures, allow nowadays to design and build lighter and low stiffness and damping structures, turning them into elements of high sensitivity against wind-induced dynamic effects. The purpose of this work is to describe and to apply a simple calculation methodology that enables the determination of the longitudinal dynamic response of tall buildings in time domain. The wind velocity field is reproduced by velocity series that incorporate the coherence function which then are transformed into fluctuating nodal forces using the quasi-static loading model. Furthermore, to include the effect of imperfect averaging associated with the discretized nodes, the aerodynamic admittance function is added. Through the proposed methodology two structures widely studied by other authors are analyzed: a steel tower and the CAARC Standard Tall Building. The results thus obtained show agreement with those reported in the literature.Peer Reviewe
X-boson cumulant approach to the periodic Anderson model
The Periodic Anderson Model (PAM) can be studied in the infinite U limit by
employing the Hubbard X operators to project out the unwanted states. We have
already studied this problem employing the cumulant expansion with the
hybridization as perturbation, but the probability conservation of the local
states (completeness) is not usually satisfied when partial expansions like the
Chain Approximation (CHA) are employed. Here we treat the problem by a
technique inspired in the mean field approximation of Coleman's slave-bosons
method, and we obtain a description that avoids the unwanted phase transition
that appears in the mean-field slave-boson method both when the chemical
potential is greater than the localized level Ef at low temperatures (T) and
for all parameters at intermediate T.Comment: Submited to Physical Review B 14 pages, 17 eps figures inserted in
the tex
Photoelasticity as a Research Technique for Analyzing Stresses in Dental Structures
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67063/2/10.1177_00220345550340060601.pd
Contribution to ehtno-genetic chatacterisation of anandalusian canine dog racial group
We are analysing a sample of 53 animals (16 males and 37 females) of Andalusian mouse hunter dogs or caves dog, with a view to obtain their ethnogenetic characterisation. From our results we have concluded that this population is a racial group presenting a great homogeneity in the variables and zoometric indexes studied, as in the phaneroptical aspects. Their morphology is as a small format, probably elipometrics, with proportional leg length, brevilineous cephalic and body proportions. This population present a three-coloured coat, generally white colour on the body and “black and tan” on the head; the hair is short and smooth, the mucosae is black and the iris brown. With respect the bite, the most frequent are the tweezers form and the scissors, also in few animals we have found the absence of premolars.Se analiza una muestra de perros ratoneros o bodegueros compuesta por 53 ejemplares de los cuales 16 eran machos y 37 hembras, con objeto de lograr una caracterización etnogenética. De los resultados obtenidos concluimos que se trata de una agrupación racial que presenta gran homogeneidad tanto en las variables e índices zoométricos estudiados como en los aspectos fanerópticos. Morfológicamente se trata de animales de formato pequeño, posiblemente elipométricos, ni lejos ni cerca de tierra, y de proporciones braquicéfalas y brevilíneas en cuanto a sus proporciones cefálicas y corporales respectivamente. Fanerópticamente esta población presenta una capa tricolor, generalmente blanco en el cuerpo y negro-fuego en la cabeza, el pelo corto y liso, la pigmentación de las mucosas negras y el iris castaño. En cuanto a la mordida los tipos más frecuentes son en tijera y pinza, y en un escaso número de ejemplares existe ausencia de premolares
Frequencies of deletereus character in the spanish water dog affecting the breed conservation
321 puppies of the Spanish Water Dog Breed have been used to study the frequency of presentation of several deleterious characters between the years 1995 and 1998. The enogmatism and the monorquidism shown frequencies relatively low, but we stand out these characters because their control is very important for the relationship with respect the adaptive capacity of these animals. In the same way the prognatism and the absence of premolars were present with a frequency slightly high, it must take into account in the selection criteria of the breed. By another side, we found a signifficative association between the presence of heath anomalies and slightly high populational levels of inbreeding, and then we have to avoid these breeding practices in the racial lines presenting this defect.Sobre un total de 321 cachorros nacidos de la raza Perro de Agua Español entre los años 1995 y 1998 se estudian las frecuencias de aparición de diferentes caracteres deletéreos. Los caracteres enogmatismo y monorquidia muestran unas frecuencias relativamente bajas, si bien destacamos la importancia de su control ya que su expresión afecta a la capacidad adaptativa de los animales. Asimismo, el prognatismo y la ausencia de premolares se presentan con unas frecuencias moderadamente altas que recomendamos incluir en los criterios de selección de la raza. Por otra parte, encontramos asociación significativa entre la aparición de anomalías cardíacas y niveles relativamente altos de endogamia en la población por lo que se desaconseja la endocría en las líneas raciales que presentan este defecto
Kinetics of TNF-alpha and IFN-gamma mRNA expression in islets and spleen of NOD mice
Insulin-dependent diabetes mellitus is caused by autoimmune destruction of pancreatic ß cells. Non-obese diabetic (NOD) mice spontaneously develop diabetes similar to the human disease. Cytokines produced by islet-infiltrating mononuclear cells may be directly cytotoxic and can be involved in islet destruction coordinated by CD4+ and CD8+ cells. We utilized a semiquantitative RT-PCR assay to analyze in vitro the mRNA expression of TNF-alpha and IFN-gamma cytokine genes in isolated islets (N = 100) and spleen cells (5 x 10(5) cells) from female NOD mice during the development of diabetes and from female CBA-j mice as a related control strain that does not develop diabetes. Cytokine mRNAs were measured at 2, 4, 8, 14 and 28 weeks of age from the onset of insulitis to the development of overt diabetes. An increase in IFN-gamma expression in islets was observed for females aged 28 weeks (149 ± 29 arbitrary units (AU), P<0.05, Student t-test) with advanced destructive insulitis when compared with CBA-j mice, while TNF-alpha was expressed in both NOD and CBA-j female islets at the same level at all ages studied. In contrast, TNF-alpha in spleen was expressed at higher levels in NOD females at 14 weeks (99 ± 8 AU, P<0.05) and 28 weeks (144 ± 17 AU, P<0.05) of age when compared to CBA-j mice. The data suggest that IFN-gamma and TNF-alpha expression in pancreatic islets of female NOD mice is associated with ß cell destruction and overt diabetes.1347135
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