Raw materials and their utilization in the Chico and Santa Cruz river basins (Santa Cruz province, Argentine Patagonia)

En este trabajo se sintetizan y actualizan los resultados de los relevamientos de materias primas líticas realizados en el extremo sur del Macizo del Deseado, el curso medio del río Chico y en diferentes sectores de la cuenca del río Santa Cruz. Se presentan las variables registradas, así como las razones de las modificaciones introducidas en la metodología de su relevamiento a través del tiempo. Los resultados se integraron en una base de datos que posee un correlato de muestras de mano, identificadas en casos seleccionados mediante cortes delgados. Se hicieron análisis geoquímicos sobre algunas muestras. La información obtenida da cuenta no sólo de las características macroscópicas de las materias primas, sino también de su forma de presentación, dispersión en el espacio y visibilidad. Estos datos se utilizan para evaluar los cambios en el registro arqueológico y sus implicaciones en relación con el comportamiento humano.The purpose of this paper is to present a summary of the results obtained in raw material samplings which took place in different localities within the southern end of the Deseado Massif, the middle Chico river basin and the upper and lower Santa Cruz river basin. Variables considered as well as modifications introduced in the methodology through time are described. Results obtained were introduced into a data base, which has a correlative set of hand samples that, in selected cases, were identified through thin sections. In some cases, geochemical analyzes were carried on. Data acquired inform us about the macroscopical characteristics of raw materials, their availability, spatial dispersion and visibility. This information is used to analyze changes in the archeological record and their implications for human behavior.Fil: Franco, Nora Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Multidisciplinario de Historia y Ciencias Humanas; ArgentinaFil: Ambrustolo, Pablo. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. División Arqueología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Vetrisano, Pablo. Universidad de Buenos Aires. Facultad de Filosofia y Letras. Departamento de Ciencias Antropologicas; Argentin

Analysis and performance of complete homogeneous communication networks

In this paper we address a fundamental problem in communication systems. A fully-connected system is modelled by a complete graph, where all nodes have identical capacities. A message is owned by a singleton. If he/she decides to forward the message simultaneously to several nodes, he/she will take longer (exactly, the number of simultaneous nodes times a single forwarding scheme). The only rule in this communication system is that a message can be forwarded by a node only if it fully known. The makespan is the completion time, precisely when the message is fully known by all nodes. The average waiting time is the average among the completion time of all individual nodes. The problem under study is to select the communication strategy that minimizes both the makespan and average waiting time. Intuition and current design of real networks say that oneto- many systems should perform better than one-to-one systems, however this is not usually true. A previous study claims that a sequential or one-to-one forwarding scheme minimizes the average waiting time, but they do not offer a proof. Here, a formal proof is included. Furthermore, we show that the sequential strategy minimizes the makespan as well. The paper is closed with comments on potential applications in scheduling of parallel machines, content delivery networks, peer-to-peer systems and rumour spreading

Tribunales constitucionales y políticas económicas caso Colombiano

This article shows the different positions about the debate between law and economy, especially, the competence, legitimacy and convenience of constitutional courts intervention in the making of economic policies. To do it, Firstly, we present the general context of the evolution of constitutional law, that is to say, the growing importance and power of constitutional courts in the contemporary democratic societies. Secondly, we focus in Colombian case, for that reason, (i) we explain why the Colombian case is relevant for our research, (ii) we describe the Colombian constitutional law background, (iii) we present the main effects of the Colombian Constitutional Court decisions in the Colombian economy as well as the criticism about the Constitutional Court's activity, (iv) we emphasize in the role of Colombian Constitutional Court in defining health policy.Thirdly, we summarize the main arguments for and against the intervention of Colombian Constitutional Court in the making of economic policies in general, and the Colombian health policy in particular. Finally, we expose some final conclusions.Este artículo muestra las diferentes posiciones sobre el debate entre el derecho y economía, especialmente la competencia, legitimidad y comodidad de los tribunales constitucionales, intervención en la adopción de políticas económicas.En primer lugar, presentamos el contexto general de la evolución del derecho constitucional, es decir, la importancia creciente y el poder de los tribunales constitucionales en el actual contexto de las sociedades democráticas. En segundo lugar, nos concentramos en el caso Colombiano; por esta razón, (i) nos explicamos por qué el caso colombiano es pertinente para nuestra investigación, ii) describimos los antecedentes del derecho constitucional colombiano, (iii) presentamos los efectos principales de la Corte Constitucional Colombiana y sus decisiones en la economía Colombiana, así como las críticas sobre la actividad del Tribunal Constitucional, y (iv) hacemos hincapié en la función de la Corte Constitucional Colombiana para definir la política sanitaria. En tercer lugar, resumimos los principales argumentos en pro y contra la intervención de la Corte Constitucional Colombiana en la adopción de políticas económicas en general, y la política sanitaria en particular. Por último, exponemos algunas conclusiones finales

A simulation Method for Network Performability Estimation using Heuristically-computed Pathsets and Cutsets

Consider a set of terminal nodes K that belong to a network whose nodes are connected by links that fail independently with known probabilities. We introduce a method for estimating any performability measure that depends on the hop distance between terminal nodes. It generalises previously introduced Monte Carlo methods for estimation of the K-reliability of networks with variance reduction compared to crude Monte Carlo. They are based on using sets of edges named d-pathsets and d-cutsets for reducing the variance of the estimator. These sets of edges, considered as a priori known in previous literature, heaviliy affect the attained performance; we hereby introduce and compare a family of heuristics for their selection. Numerical examples are presented, showing the significant efficiency improvements that can be obtained by chaining the edge set selection heuristics to the proposed Monte Carlo sampling plan

The Role of Social and Institutional Contexts in Social Innovations of Spanish Academic Spinoffs

Social innovations developed by academic spinoffs (ASOs) are acquiring an ever-increasing relevance in the literature on academic entrepreneurship. Previous studies have considered the importance of the social and institutional contexts of entrepreneurial ecosystems for the development of these innovations, although a greater depth of analysis is required in this field of study. This research analyzes the influence of the frequency of contact with agents of social and institutional contexts of the entrepreneurial ecosystem on the social innovations of ASOs. From a sample of 173 Spanish ASOs, the results indicate that frequent contact with government and academic support units improves this type of innovation of ASOs. Regarding social context, an increase in the frequency of contact with customers, suppliers, and competitors favors the development of social innovation. However, frequent contact with venture capital firms inhibits the development of this type of innovation

Width of the charge-transfer peak in the SU(N) impurity Anderson model and its relevance to nonequilibrium transport

We calculate the width 2ΔCT and intensity of the charge-transfer peak (the one lying at the on-site energy Ed) in the impurity spectral density of states as a function of Ed in the SU(N) impurity Anderson model (IAM). We use the dynamical density-matrix renormalization group (DDMRG) and the noncrossing approximation (NCA) for N=4 and a 1/N variational approximation in the general case. In particular, while for Ed Δ, where Δ is the resonant level half-width, ΔCT=Δ as expected in the noninteracting case, for Ed NΔ one has ΔCT=NΔ. In the N=2 case, some effects of the variation of ΔCT with Ed were observed in the conductance through a quantum dot connected asymmetrically to conducting leads at finite bias [J. Könemann, Phys. Rev. B 73, 033313 (2006)PRBMDO1098-012110.1103/PhysRevB.73.033313]. More dramatic effects are expected in similar experiments that can be carried out in systems of two quantum dots, carbon nanotubes or other, realizing the SU(4) IAM.Fil: Fernández, Joaquín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Lisandrini, Franco Thomas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; ArgentinaFil: Roura Bas, Pablo Gines. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gazza, Claudio Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; ArgentinaFil: Aligia, Armando Ángel. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentin

Aerobic power, huddling and the efficiency of torpor in the South American marsupial, Dromiciops gliroides.

During periods of cold, small endotherms depend on a continuous supply of food and energy to maintain euthermic body temperature (T(b)), which can be challenging if food is limited. In these conditions, energy-saving strategies are critical to reduce the energetic requirements for survival. Mammals from temperate regions show a wide arrange of such strategies, including torpor and huddling. Here we provide a quantitative description of thermoregulatory capacities and energy-saving strategies in Dromiciops gliroides, a Microbiotherid marsupial inhabiting temperate rain forests. Unlike many mammals from temperate regions, preliminary studies have suggested that this species has low capacity for control and regulation of body temperature, but there is still an incomplete picture of its bioenergetics. In order to more fully understand the physiological capacities of this "living fossil", we measured its scope of aerobic power and the interaction between huddling and torpor. Specifically, we evaluated: (1) the relation between basal (BMR) and maximum metabolic rate (MMR), and (2) the role of huddling on the characteristics of torpor at different temperatures. We found that BMR and MMR were above the expected values for marsupials and the factorial aerobic scope (from [Formula: see text]CO(2)) was 6.0±0.45 (using [Formula: see text]CO(2)) and 6.2±0.23 (using [Formula: see text]O(2)), an unusually low value for mammals. Also, repeatability of physiological variables was non-significant, as in previous studies, suggesting poor time-consistency of energy metabolism. Comparisons of energy expenditure and body temperature (using attached data-loggers) between grouped and isolated individuals showed that at 20°C both average resting metabolic rate and body temperature were higher in groups, essentially because animals remained non-torpid. At 10°C, however, all individuals became torpid and no differences were observed between grouped and isolated individuals. In summary, our study suggests that the main response of Dromiciops gliroides to low ambient temperature is reduced body temperature and torpor, irrespective of huddling. Low aerobic power and low time-consistency of most thermoregulatory traits of Dromiciops gliroides support the idea of poor thermoregulatory abilities in this species

Una compliance pulmonar disminuida incrementa los test dinámicos de precarga en un modelo pediátrico de lesión pulmonar aguda

Indexación: Web of Science; Scielo.Background Preload dynamic tests, pulse pressure variation (PPV) and stroke volume variation (SVV) have emerged as powerful tools to predict response to fluid administration. The influence of factors other than preload in dynamic preload test is currently poorly understood in pediatrics. The aim of our study was to assess the effect of tidal volume (VT) on PPV and SVV in the context of normal and reduced lung compliance in a piglet model. Material and method Twenty large-white piglets (5.2 ± 0.4 kg) were anesthetized, paralyzed and monitored with pulse contour analysis. PPV and SVV were recorded during mechanical ventilation with a VT of 6 and 12 mL/kg (low and high VT, respectively), both before and after tracheal instillation of polysorbate 20. Results Before acute lung injury (ALI) induction, modifications of VT did not significantly change PPV and SVV readings. After ALI, PPV and SVV were significantly greater during ventilation with a high VT compared to a low VT (PPV increased from 8.9 ± 1.2 to 12.4 ± 1.1%, and SVV from 8.5 ± 1.0 to 12.7 ± 1.2%, both P < 0.01). Conclusions This study found that a high VT and reduced lung compliance due to ALI increase preload dynamic tests, with a greater influence of the latter. In subjects with ALI, lung compliance should be considered when interpreting the preload dynamic tests.Introducción Test dinámicos de precarga, variación de presión de pulso (PPV) y variación de volumen sistólico (SVV) han emergido como herramientas poderosas para predecir respuesta a la administración de fluidos. Actualmente la influencia de factores distintos a la precarga en la determinación de los test dinámicos de precarga es pobremente conocida en pediatría. Nuestro objetivo fue medir el efecto del volumen tidal (VT) sobre PPV y SVV en un contexto de compliance pulmonar normal y disminuida en un modelo porcino. Material y método Veinte cerditos Large-White anestesiados y paralizados (5,2 ± 0,4 kg). PPV y SVV fueron medidos por análisis de contorno de pulso durante ventilación con VT de 6 y 12 mL/kg (VT bajo y alto, respectivamente), ambos previo y posterior a lesión pulmonar aguda (ALI) químicamente inducida con instilación traqueal de polisorbato 20. Resultados Previo a inducción de ALI, PPV y SVV no tuvieron cambios significativos al modificar el VT. Sin embargo, después de ALI, PPV y SVV fueron significativamente mayores durante ventilación con VT alto, respecto a VT bajo (PPV aumentó de 8,9 ± 1,2 a 12,4 ± 1,1%, y SVV de 8,5 ± 1,0 a 12,7 ± 1,2%, ambos P < 0,01). Conclusiones Este estudio encontró que un VT alto y una compliance pulmonar disminuida debido a ALI incrementan los test dinámicos de precarga, con una mayor influencia de esta última. En sujetos con ALI la compliance pulmonar debiera ser considerada al interpretar los test dinámicos de precarga.http://ref.scielo.org/3fhq5