A U-Pb Study of Zircons from a Lower Crustal Granulite Xenolith of the Spanish Central System: A Record of Iberian Lithospheric Evolution from the Neoproterozoic to the Triassic

A U-Pb laser ablation inductively coupled plasma mass spectrometry and secondary ion mass spectrometry geochronological study has been performed on zircons from a felsic granulite xenolith from the lower crust under the Variscan belt of Iberia. The ages obtained reveal zircon-forming events that span from the late Neoproterozoic (Cadomian-Avalonian orogeny) to the early stages of the opening of the Atlantic Ocean in the Mesozoic, through Cambro-Ordovician rifting, Devono-Carboniferous Variscan-Alleghenian collision, and Permian-Triassic extension and uplift. The U-Pb age groups found in zircons from this single lower crustal xenolith (ca. 220, 250, 280–310, 460–490, 525, and 550–490 Ma) record at least one complete cycle of closing and opening of oceanic basins and collision of continental masses. Zircons from the felsic granulite xenolith contain a synthesis of the geochronological information found on the surface geology and record most but not all major lithospheric events in the region in a ca. 400-m.yr. period

Tool wear evaluation in drilling by acoustic emission

AbstractA drilling process with different degrees of wear in the drill bit was studied to find relationships between acoustic emission (AE) and torque measured during the drilling process, and also with the degree of wear of the tool.SAE 1040 steel samples were drilled, making holes with 5 mm diameter twist drill bits in continuous feed. The drill bits were modified with “artificial” (produced by spark-erosion) and “real” (obtained by regular mechanical use) failures such as different degrees of wear in the cutting edge and the outer corner. For every drilled hole, torque and AE were simultaneously measured and acquired.In the first part of this work, the correlation between the AE parameters and torque measured during the drilling process is studied. Torque was measured as a control parameter to follow the dynamic behaviour of the drill bit. An alternative AE feature, called Mean Power (MP) showed a good correlation with torque when the moving average (MA) was computed.In the second part, the AE mean power (MP) was related to different degrees of wear in drill bits. Clusters for the different levels of wear in a 2-D plot were obtained. In that plot the moving variance of the MP vs. the moving average of the MP, for each case of wear, were represented.This application aims at repetitive manufacturing operations, where many signals per second may be obtained with fixed parameters as shape, drill bit diameter, spindle speed, feed, and a good statistical study can be done

Socioeconomic background and academic achievement. The case of an argentine university

El objetivo de la investigación es determinar mediante regresiones estadísticas las relaciones entre las características socioeconómicas de los alumnos de las carreras de grado de la Universidad Nacional del Nordeste (UNNE, Argentina) y sus resultados académicos, y compararlos con los hallazgos de estudios similares efectuados en otras universidades nacionales. Se encuentra evidencia contundente de que las variables de Nivel Socioeconómico (NSE) son significativas para explicar las diferencias de rendimiento académico entre los alumnos de las facultades analizadas. Las variables que se han utilizado como indicadores de NSE elevado han presentado una correlación positiva, y las variables que se emplearon como indicadores de NSE más bajo han presentado una correlación negativa. Las variables sexo femenino, edad, estado civil casado y situación laboral inactiva están asociadas a un mejor rendimiento académico, mientras que las variables cantidad de hijos del estudiante, situación laboral ocupado, situación laboral desocupado, ausencia de cobertura médica y beneficiario de planes sociales están relacionadas a menores desempeños académicos. En materia de género, el hallazgo más relevante se manifiesta en los resultados de las estudiantes mujeres con hijos: su rendimiento es notoriamente inferior al de los estudiantes hombres con hijosThe aim of our research is to assess the relationships between socioeconomic characteristics of students in undergraduate courses of Northeastern University (UNNE, Argentina) and their academic results using statistical regression, and to compare the findings with the ones obtained in similar studies in other national universities. There is strong evidence that variables of Socioeconomic Status (SES) are significant in explaining the differences in academic achievement between students of the several schools. The variables used as indicators of high SES presented a positive correlation, and variables that were used as indicators of lower SES have presented a negative correlation. The variables female sex, age, married marital status and inactive employment status are associated with better academic performance, while the variables number of children of the student, busy employment status, employment status, medical coverage, and beneficiary of social plans are related to lower academic performance. Regarding gender, the most important finding is that female students with children have lower performance than male students with childre

Performance Models for Frost Prediction in Public Cloud Infrastructures

Sensor Clouds have opened new opportunities for agricultural monitoring. These infrastructures use Wireless Sensor Networks (WSNs) to collect data on-field and Cloud Computing services to store and process them. Among other applications of Sensor Clouds, frost prevention is of special interest among grapevine producers in the Province of Mendoza - Argentina, since frost is one of the main causes of economic loss in the province. Currently, there is a wide offer of public cloud services that can be used in order to process data collected by Sensor Clouds. Therefore, there is a need for tools to determine which instance is the most appropriate in terms of execution time and economic costs for running frost prediction applications in an isolated or cluster way. In this paper, we develop models to estimate the performance of different Amazon EC2 instances for processing frosts prediction applications. Finally, we obtain results that show which is the best instance for processing these applications

Modulation of glycolisis and the pentose phosphate pathway influences porcine oocyte in vitro maturation

Glycolytic and pentose phosphate pathway (PPP) activities were modulated in porcine cumulus-oocyte complexes (COCs) during in vitro maturation (IVM) by the addition of inhibitors or stimulators of key enzymes of the pathways to elucidate their relative participation in oocyte maturation. The activities of glycolysis and PPP were evaluated by lactate production per COC and by the brilliant cresyl blue test, respectively. Glucose uptake per COC and the oocyte maturation rate were also evaluated. Lactate production, glucose uptake and the percentage of oocytes reaching metaphase II decreased in a dose-dependent manner in the presence of the pharmacological (NaF) or the physiological (ATP) inhibitors of glycolysis (p < 0.05). The addition of the physiological stimulator of glycolysis (AMP) caused no effect on lactate production, glucose uptake or the meiotic maturation rate. The pharmacological (6-AN) and the physiological (NADPH) inhibitors of PPP induced a dose-dependent decrease in the percentage of oocytes with high PPP activity and in the nuclear maturation rate (p < 0.05). The physiological stimulator of PPP (NADP) caused no effect on the percentage of oocytes with high PPP activity. The glycolytic and PPP activities of porcine COCs and maturational competence of oocytes seem to be closely related events. This study shows for the first time the regulatory effect of ATP and NADPH as physiological inhibitors of glycolysis and PPP in porcine COCs, respectively. Besides, these pathways seem to reach their maximum activities in porcine COCs during IVM because no further increases were achieved by the presence of AMP or NADP.Fil: Alvarez, Gabriel Martín. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Instituto de Investigacion y Tecnología en Reproducción Animal; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario; ArgentinaFil: Ferretti, E. L.. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Instituto de Investigacion y Tecnología en Reproducción Animal; ArgentinaFil: Gutnisky, Cynthia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Instituto de Investigacion y Tecnología en Reproducción Animal; ArgentinaFil: Dalvit, Gabriel Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Instituto de Investigacion y Tecnología en Reproducción Animal; ArgentinaFil: Cetica, Pablo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Veterinarias. Instituto de Investigacion y Tecnología en Reproducción Animal; Argentin

Geometría experimental en el espacio: uso de la teoría de homografías y del software cabri 3D para resolver un problema de geometría en el espacio

Se resuelve el problema: Dadas tres rectas paralelas no coplanares, construir un triángulo equilátero que tenga sus tres vértices sobre las rectas. Se utiliza una estrategia de geometría experimental: Con base en figuras dinámicas construidas en Cabri 3D se hace el análisis del problema, se formulan conjeturas y se formalizan los procesos de razonamiento utilizando la teoría de las homografías

The Strategy of Combining Antidepressants in the Treatment of Major Depression: Clinical Experience in Spanish Outpatients

Introduction. The combination of antidepressants is a useful tool in the treatment of major depression, especially in cases where there is a partial response to antidepressant monotherapy. However, the use of this strategy is a matter of controversy, and its frequency of use in clinical practice is not clear. The aim of our study is to assess the use of antidepressants combination in Spain by reviewing three databases used between 1997 and 2001. Methods. Databases pertain to patients who are study subjects of major depression treatment. These databases are a result of studies performed in Spain and in which 550 psychiatrists participated. The total studied sample was comprised of N = 2, 842 patients, aged over 18, fitting DSM-IV criteria for Major Depressive Episode. The percentage of patients who received more than one antidepressant and the types of combinations used was described. Subsequently, a comparative study between the group which received a combination of antidepressants (N = 64) and the group which received antidepressant monotherapy (N = 775) was performed. Results. 27.1% of patients were on antidepressive monotherapy treatment, and 2.2% were on combination therapy. In the comparison of patients on combination therapy and monotherapy, there were significant differences only in episode duration (P = 0.001). The most frequent combinations are SSRIs and tricyclic antidepressants. The active principle most widely combined is fluoxetine. Conclusions. The prevalence of use of antidepressant combination therapy is 2.2% of the global sample and 8.3% of treated patients. Other than duration of the depressive episode, no clinical characteristics exclusive to patients who received combination rather than monotherapy were found. Our study found that the most frequent combination is SSRIs + TCAs, also being the most studied

Administration of a peptide inhibitor of alpha4-integrin inhibits the development of experimental autoimmune uveitis

Recruitment of lymphocytes into the retina and to the vitreous during the development of experimental autoimmune uveitis (EAU) is governed by factors such as the state of activation of inflammatory cells and the repertoire of adhesion molecules expressed by the local vascular endothelia. alpha4 Integrins and their receptors play an important role during homing of cells to the inflammatory site. In the present study, the effect of alpha4-integrin inhibitor on the development of EAU was investigated.Fil: Martín, Andrea P.. Universidade de Sao Paulo; BrasilFil: Vieira de Moraes, Luciana. Universidade de Sao Paulo; BrasilFil: Tadokoro, Carlos E.. Universidade de Sao Paulo; BrasilFil: Commodaro, Alessandra G.. Universidade de Sao Paulo; BrasilFil: Urrets Zavalia, Enrique. Universidad Catolica de Córdoba. Facultad de Medicina. Clinica Universitaria Reina Fabiola; ArgentinaFil: Rabinovich, Gabriel Adrián. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Urrets Zavalía, Julio Alberto. Universidad Catolica de Córdoba. Facultad de Medicina. Clinica Universitaria Reina Fabiola; ArgentinaFil: Rizzo, Luiz V.. Universidade de Sao Paulo; Brasil. Fundação Zerbini; BrasilFil: Serra, Horacio Marcelo. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas; Argentin

Cycloidal Domains in the Magnetization Reversal Process of Ni80Fe20/Nd16Co84/Gd12Co88 Trilayers

The magnetization reversal of each individual layer in magnetic trilayers ( permalloy / Nd Co / Gd Co ) is investigated in detail with x-ray microscopy and micromagnetic calculations. Two sequential inversion mechanisms are identified. First, magnetic vortex-antivortex pairs move along the field direction while inverting the magnetization of magnetic stripes until they are pinned by defects. The vortex-antivortex displacements are reversible within a field interval which allows their controlled motion. Second, as the reversed magnetic field increases, cycloidal domains appear in the permalloy layer as a consequence of the dissociation of vortex-antivortex pairs due to pinning. The field range where magnetic vortices and antivortices are effectively guided by the stripe pattern is of the order of tens of mT for the Ni Fe layer, as estimated from the stability of cycloid domains in the sample

Dissipation-driven generation of two-qubit entanglement mediated by plasmonic waveguides

We study the generation of entanglement between two distant qubits mediated by the surface plasmons of a metallic waveguide. We show that a V-shaped channel milled in a flat metallic surface is much more efficient for this purpose than a metallic cylinder. The role of the misalignments of the dipole moments of the qubits, an aspect of great importance for experimental implementations, is also studied. A careful analysis of the quantum-dynamics of the system by means of a master equation shows that two-qubit entanglement generation is essentially due to the dissipative part of the effective qubit-qubit coupling provided by the surface plasmons. The influence of a coherent external pumping, needed to achieve a steady state entanglement, is discussed. Finally, we pay attention to the question of how to get information experimentally on the degree of entanglement achieved in the system.Comment: 13 pages, 12 figure