3,823 research outputs found

    The influence of Tellurium an Folic Acid Adminitration on Coping Behavioural Parameters in Maturing Rats: Transgenerational effects

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    A previous study of our laboratory have shown that Tellurium (Te), a metalloid with low concentrations in soil and water in the earth, is able to modify important behavioural parameters related to cognitive functions when administered orally in maturing rats. Exposition of chronic non-toxic doses of Te affected spontaneous lateralized exploration, social interaction behaviour, and survival responses in the treated rats. Te effects were blocked by the simultaneous administration of folic acid, a well-known methyl group donor in the cell, suggesting an epigenetic mode of action of Te. Te behavioural effects on the second generation (F1 ) still were found in the next third generation (F2 ). In order to evaluate if these transgenerational behavioural alterations in F2 were depending on DNA methylating mechanisms, as observed in the F1 generation, F1 rats were mated at 90 days of age. Two groups of animals in the F2 offspring were formed; one treated with and the other not treated with folic acid. Results showed that the untreated folic acid F2 maturing rats, conserved the same pattern of behavioural alterations than its parents (F1 ), in spite that they were not exposed to Te. Those F2 animals treated with folic acid, instead recovered the normal behavioural responses in the three tests performed to evaluate coping behaviour. Results suggest that the molecular mechanism of Te is dependent on DNA methylating reactions, which is one of the molecular processes of epigenetic modulation in mammalsFil: Ratti, Silvia Gabriela. Universidad Nacional de Cuyo; ArgentinaFil: Sacchi, Osvaldo Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: Alvarez, Edgardo O. Universidad Nacional de Cuyo; Argentin

    A Parallel Preconditioner for 2D Elliptic Boundary Value Problems

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    This work presents the implementation on a Linux Cluster of a parallel preconditioner for the solution of the linear system resulting from the finite element discretization of a 2D second order elliptic boundary value problem. The numerical method, proposed by Bramble, Pasciak and Schatz, is developed using Domain Decomposition techniques, which are based on the splitting of the computational domain into subregions of smaller size, enforcing suitable compatibility conditions. The Fortran code is implemented using PETSc: a suite of data structures and routines devoted to the scientific parallel computing and based on the MPI standard for all message-passing communications. The main interest of the paper is to investigate how the architectural aspects of the cluster influence the performance of the considered algorithm. We provide an analysis of the execution times as well as of the scalability, using as test case the classical Poisson equation with Dirichlet boundary conditions

    Optimal estimation of group transformations using entanglement

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    We derive the optimal input states and the optimal quantum measurements for estimating the unitary action of a given symmetry group, showing how the optimal performance is obtained with a suitable use of entanglement. Optimality is defined in a Bayesian sense, as minimization of the average value of a given cost function. We introduce a class of cost functions that generalizes the Holevo class for phase estimation, and show that for states of the optimal form all functions in such a class lead to the same optimal measurement. A first application of the main result is the complete proof of the optimal efficiency in the transmission of a Cartesian reference frame. As a second application, we derive the optimal estimation of a completely unknown two-qubit maximally entangled state, provided that N copies of the state are available. In the limit of large N, the fidelity of the optimal estimation is shown to be 1-3/(4N).Comment: 11 pages, no figure

    Aplicación de la clasificación ATC al análisis de las prescripciones en DAMSU : I : los grupos de medicamentos que encabezan el ranking

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    Este es un estudio sobre utilización de medicamentos donde se analiza la evolución de la prescripción, en DAMSU de UNCuyo, de los 14 grupos terapéuticos (GT) de la clasificación ATC, durante 4 años consecutivos. Su objetivo fue determinar la prevalencia de las prescripciones en los 3 primeros niveles de la clasificación. Los datos fueron recolectados en los meses de abril, junio, setiembre y diciembre utilizando la metodología del DURG y procesados con un programa EPI INFO. Las comparaciones estadísticas fueron realizadas mediante la Prueba no paramétrica de los Signos. El ranking de GT fue constante pero el total de prescripciones disminuyó significativamente entre 2004 y 2007. Los GT del 1º nivel: S. Nervioso (N), S. cardiovascular (C), Digestivo y Metabolismo (A) y Músculo-esquelético (M), ocuparon, en orden decreciente, los cuatro primeros puestos del ranking durante los 4 años. De estos GT fueron analizados los subgrupos del 2º y 3º nivel. La prescripción de Psicolépticos + Psicoanalépticos superó a la de Analgésicos en el grupo N. En el grupo C los Agentes Antihipertensivos, y entre ellos los IECAs, encabezaron el ranking. Las vitaminas fueron las primeras en el GT A y el subgrupo de Antiinflamatorios y Antirreumáticos en el GT M. Se discuten estos resultados en función de la racionalidad de las prescripciones.This is a drug utilization research on the evolution of drug prescription in DAMSU of UNCuyo, during 4 consecutive years, comprising the 14 therapeutic groups (TG) of the ATC classification. The object was to determine the prescription prevalence in the 3 first levels of this classification. Data from April, June, September and December were collected according to the DURG methodology and processed by an EPI INFO program. Statistic comparisons were done with the nonparametric Signs Test. The TG ranking was constant but the total drug prescription lowered significantly between 2004 and 2007. Four TG at the first level were: Nervous S. (N), Cardiovascular S. (C), Digestive and Metabolism (A) and Muscle-Squeletal (M) shared in a decreasing order the first 4 places of the ranking in the 4 scored years. From these TG the 2º and 3º subgroups were analyzed. In the TG N the prescription of psychodrugs (Psycholeptics + Psychoanaleptics) was higher than that of Analgesics. In the TG C the Antihipertensive Agents, among which the ACEIs drugs are, did head the ranking. Vitamins were the first in the TG A and the subgroup of Anti-inflammatory and Antirheumatics headed the TG M. Results are discussed in terms of rationality of prescriptions.Fil: Sacchi, O. J.. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Departamento de PatologíaFil: Kaiser, L. D.. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Departamento de PatologíaFil: Riestra, E. C.. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Departamento de PatologíaFil: Rodríguez, C. I.. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Departamento de PatologíaFil: Zapata, M. P.. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Departamento de PatologíaFil: Rodríguez Echandía, Eduardo. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Departamento de Patologí

    Single Event Upset tests and failure rate estimation for a front-end ASIC adopted in high-flux-particle therapy applications

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    none8A 64 channels Application Specific Integrated Circuit, named TERA09, designed in a 0.35 m technology for particle therapy applications, has been characterized for Single Event Upset probability. TERA09 is a current-to-frequency converter that offers a wide input range, extending from few nA to hundreds of A, with linearity deviations in the order of a few percent. This device operates as front-end readout electronics for parallel plate ionization chambers adopted in clinical applications. This chip is going to be located beside the monitor chamber, thus not directly exposed to the particle beam. For this reason, no radiation hardening techniques were adopted during the microelectronics design. The intent of the test reported in this paper is to predict the TERA09 upset rate probability in a real application scenario. Due to the fact that TERA09 has an extended digital area with registers and counters, it is interesting to estimate the effect of the secondary neutron field produced during the treatment. The radiation damage test took place at the SIRAD facility of the Italian National Institute for Nuclear Physics in Padova, Italy. The SIRAD facility allows to study the CMOS upset rate as a function of the energy deposited during irradiation. By irradiating the chip with ions of different Linear Energy Transfer, it is possible to calculate the single event effect cross-section as a function of the deposited energy. It resulted that the minimum deposited energy in a CMOS silicon sensitive volume of , responsible for a Single Event Upset probability higher than zero, is 690 keV. In the last part of the paper, we calculated the expected upset probability in a typical clinical environment, knowing the fluence of secondary, backward-emitted neutrons. Considering as an example a treatment room located at the CNAO particle therapy center in Pavia, the expected upset rate for TERA09 is events/year. Using a redundant and independent monitor chamber, the upset probability expected during one detector readout is lower than , as explained in the document.noneFausti, F.; Mazza, G.; Giordanengo, S.; Hammad Ali, O.; Manganaro, L.; Monaco, V.; Sacchi, R.; Cirio, R.Fausti, F.; Mazza, G.; Giordanengo, S.; Hammad Ali, O.; Manganaro, L.; Monaco, V.; Sacchi, R.; Cirio, R

    Consumo de drogas adictivas en alumnos de la UNCuyo, Mendoza, Argentina.

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    Este trabajo muestra los resultados de una encuesta realizada en 2010 sobre consumo de drogas adictivas en alumnos de 7 Facultades de la UNCUYO y los compara con los resultados obtenidos 12 años antes con una encuesta equivalente. La encuesta fue semiestructurada, con 17 preguntas, autocumplimentada, individual y anónima, con una muestra de 1108 alumnos de ambos sexos. De esa encuesta se utilizaron 7 preguntas específicas sobre drogas adictivas y una pregunta sobre consumo de medicamentos en general, con 46 opciones entre las que figuraban 10 denominaciones comerciales de benzodiacepinas, como drogas adictivas de prescripción. Para las comparaciones estadísticas se utilizó Chi cuadrado. El ranking de drogas utilizadas fue relativamente similar en 1998 y 2010 pero, exceptuando tabaco y “otras drogas" que se mantuvieron estables, el resto aumentó alrededor de 4 veces en el periodo. El 82,8% de los alumnos manifestó consumir alcohol (siempre + a veces); de 1 a 5 vasos semanales el 79%. En todas las Facultades, cerveza y Fernet encabezaron el ranquing de preferencias por bebidas alcohólicas. La prevalencia del consumo de tabaco en el total de la muestra se mantuvo constante en 1998 y 2010 (alrededor del 28%) pero el consumo entre Facultades fue variable y en Artes fue significativamente más elevado (42%). Siguen en el ranking marihuana con 10% de prevalencia, tranquilizantes con alrededor del 6% y cocaína con poco más del 1%. Finalmente “otras drogas" (Hachis, LSD, extasis, anabólicos, anfetaminas, “hongos") representaron solamente un 3% de prevalencia. Artes y Ciencias Políticas mostraron las mayores prevalencias de consumo y Derecho e Ingeniería las menores. Esto indica implementar acciones preventivas y correctivas particulares para cada Facultad.This is a research on addictive drugs use by students of 7 schools of the UNCUYO. The results of an inquire made in 2010 are compared with the results of an equivalent inquire made 12 years before. The inquire was partially structured and consists of 17 questions, autographic, individual and anonymous, and was applied to a 1108 students sample. The inquire was devoted to ascertain use and knowledge about prescription drugs use and comprised 7 specific questions on addictive drugs use as well as a prescription drugs question with 46 options comprising 10 commercial names of benzodiazepines as addictive prescription drugs. Chi square was used for statistic comparisons. The ranking of addictive drugs use was quite similar in the 1998 and the 2010 inquires. However, excepting tobacco and “other drugs" which prevalence remained constant, the rest of consigned drugs prevalence increased about 4 folds in this period. The prevalence of alcohol users was about 83% (always + some-times users) and 79% said to drank 1 to 5 glasses a week. Bear and Fernet headed the ranking of alcoholic drinks preference. The prevalence of tobacco use in the whole student sample was constant in both inquires (about 28%) but the amongschools use was variable; in Arts was significantly higher than that (42%). Followed in the ranking marihuana with a 10% prevalence, tranquilizers (about 6%) and cocaine with a little more than 1%. Finally, “other drugs" (Hachis, LSD, extasis, anabolics, anfetamines and funguses) represented all together a 3% prevalence. Arts and Politic Sciences Schools showed the highest prevalence in addictive drugs use and Law and Engineery the lowest. The results point to planning particular preventing and corrective actions for each School.Fil: Kaiser, L. D.. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Área Farmacología.Fil: Rodríguez, C.. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Área Farmacología.Fil: Zapata, M. P.. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Área Farmacología.Fil: Sacchi, O. J.. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Área Farmacología.Fil: Riestra, E. C.. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Área Farmacología.Fil: Aranda, L.. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Área Farmacología.Fil: Rodríguez Echandía, Eduardo. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas. Área Farmacología

    X-ray magneto-optics of lanthanide materials: principles and applications

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    Lanthanide metals are a particular class of magnetic materials in which the magnetic moments are carried mainly by the localized electrons of the 4f shell. They are frequently found in technically relevant systems, to achieve, e.g., high magnetic anisotropy. Magneto-optical methods in the x-ray range are well suited to study complex magnetic materials in an element-specific way. In this work, we report on recent progress on the quantitative determination of magneto-optical constants of several lanthanides in the soft x-ray region and we show some examples of applications of magneto-optics to hard-magnetic interfaces and exchange-coupled layered structures containing lanthanide elements.Comment: 7 pages, 6 figures, invited contribution to the Symposium "X-ray magneto-optics" of the Spring Meeting of the German Physical Society held in Regensburg, Germany, 8-12 March 2004. Revised version, minor change
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