Lugares y paisajes de cazadores recolectores pampeanos: una propuesta para su estudio

The landscape in hunter gatherers groups is a complex issue for the archaeological study. Thus, in this paper we introduce the idea of archaeological place as a key concept to address the problem. The characterization of places results from the integration of different lines of evidence including objects, spaces and bodies, essential parts of the material aspect of human life. The aim of this paper is to propose a research strategy centered on archaeological places that alternately focus on the field, objects, specific details of the objects and the virtual field. Subjective perspectives are also included through an anthropological fieldwork. Based on these characterizations, a discussion is proposed regarding the material and spatial relationships between places in order to outline a spatial and social network. Therefore, past social landscapes are defined as a net of interconnected places through the material evidence of the human practices and embodied experiences.El paisaje en las sociedades de los cazadores recolectores es un aspecto complejo para estudiar desde la arqueología. En este trabajo se propone la idea de lugar arqueológico como un concepto clave para abordar la problemática. Su caracterización resulta posible mediante la integración de diferentes líneas de evidencias que incluyen objetos, espacios y cuerpos, partes constitutivas de la materialidad de la vida humana. Se presenta una estrategia de investigación centrada en la caracterización de lugares arqueológicos cuyo foco se sitúa, en forma alternada, sobre el terreno, sobre los objetos, sobre detalles particulares de los objetos y sobre el terreno virtual; incluyendo, además, perspectivas subjetivas mediante la inclusión de trabajo de campo antropológico. A partir de la información obtenida en estas diferentes escalas de análisis, se evalúan las posibles relaciones materiales y espaciales entre los diferentes lugares, para un momento determinado, con el objetivo de delinear un entramado espacial. De esta forma, se definen los paisajes sociales del pasado como una red de lugares interconectados mediante las evidencias materiales de las prácticas humanas y las experiencias corporales

Sars-cov-2 and skin: The pathologist’s point of view

The SARS-CoV-2 pandemic has dramatically changed our lives and habits. In just a few months, the most advanced and efficient health systems in the world have been overwhelmed by an infectious disease that has caused 3.26 million deaths and more than 156 million cases worldwide. Although the lung is the most frequently affected organ, the skin has also resulted in being a target body district, so much so as to suggest it may be a real “sentinel” of COVID-19 disease. Here we present 17 cases of skin manifestations studied and analyzed in recent months in our Department; immunohistochemical investigations were carried out on samples for the S1 spike-protein of SARS-CoV-2, as well as electron microscopy investigations showing evidence of virions within the constituent cells of the eccrine sweat glands and the endothelium of small blood vessels. Finally, we conduct a brief review of the COVID-related skin manifestations, confirmed by immunohistochemistry and/or electron microscopy, described in the literature

The spatial structure of lithic landscapes : the late holocene record of east-central Argentina as a case study

Fil: Barrientos, Gustavo. División Antropología. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Catella, Luciana. División Arqueología. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Oliva, Fernando. Centro Estudios Arqueológicos Regionales. Facultad de Humanidades y Artes. Universidad Nacional de Rosario; Argentin

Cerro El Sombrero Cima, un lugar particular para los pobladores tempranos

Cerro El Sombrero Cima is an open air site that occupies all the summit of the highest hill in the central east portion of the Tandilia Ranges. The material assemblage has been vastly studied providing an image of a unique place during the Pleistocene/Holocene transition. The characterization of the site and the interpretation about the way in which it was inhabited by the early settlers takes into account several analysis mainly based on the study of material culture and spatial references. The aim of this paper is to present a synthesis of these analysis and their results enhancing those aspects related to the uniqueness of the place. Material culture at the site was studied through the analysis of bifacial artifacts, tools worked by grinding, abrasion and polishing, fishtail projectile points, flakes, raw materials and their transport, the past symbolic values of toolstone, tool fracture and, finally, tool use, both through microscopic studies and fatty acid analysis. Spatial analyses have focused on issues such as site placement, its dimension and density, access, visibility and visualization. Information obtained from both, the objects and the space, is combined to propose that the hilltop was a distinctive place in the landscape of the early hunter gatherers that inhabited the Pampas.Cerro El Sombrero Cima es un sitio a cielo abierto ubicado en toda la extensión de la cumbre más alta del sector centro oriental de Tandilia. El contexto material del sitio fue ampliamente estudiado dando cuenta de la particularidad de este espacio durante la transición Pleistoceno/Holoceno. La caracterización de la manera en que este sitio fue habitado por los pobladores tempranos se construyó a partir de una multiplicidad de análisis enfocados principalmente en la cultura material y la espacialidad. El objetivo de este trabajo es realizar una síntesis de dichos análisis y sus resultados, subrayando aquellos aspectos que denotan su singularidad en el contexto de las ocupaciones tempranas. La cultura material del sitio fue abordada desde el estudio de la bifacialidad, los artefactos manufacturados por picado, abrasión y pulido, las puntas cola de pescado, los desechos de manufactura, las materias primas empleadas, las modalidades de su traslado, el valor simbólico de las rocas elegidas para la talla, las fracturas de los instrumentos y el uso de los objetos por medio de análisis microscópicos y de sustancias lipídicas adheridas a sus superficies. Los análisis espaciales se han enfocado en cuestiones tales como el emplazamiento del sitio, su extensión y densidad artefactual, la accesibilidad, la visibilidad y la visibilización del sitio. La información obtenida a partir de los objetos y del espacio es integrada con el fin de caracterizar a la cima de este cerro como un lugar significativo en el paisaje de los cazadores recolectores tempranos que habitaron la pampa bonaerense

The role of conditioning in mesh selection algorithms for first order systems of linear two point boundary value problems

Codes for the numerical solution of two-point boundary value problems can now handle quite general problems in a fairly routine and reliable manner. When faced with particularly challenging equations, such as singular perturbation problems, the most efficient codes use a highly non-uniform grid in order to resolve the non-smooth parts of the solution trajectory. This grid is usually constructed using either a pointwise local error estimate defined at the grid points or else by using a local residual control. Similar error estimates are used to decide whether or not to accept a solution. Such an approach is very effective in general providing that the problem to be solved is well conditioned. However, if the problem is ill conditioned then such grid refinement algorithms may be inefficient because many iterations may be required to reach a suitable mesh on which to compute the solution. Even worse, for ill conditioned problems an inaccurate solution may be accepted even though the local error estimates may be perfectly satisfactory in that they are less than a prescribed tolerance. The primary reason for this is, of course, that for ill conditioned problems a small local error at each grid point may not produce a correspondingly small global error in the solution. In view of this it could be argued that, when solving a two-point boundary value problem in cases where we have no idea of its conditioning, we should provide an estimate of the condition number of the problem as well as the numerical solution. In this paper we consider some algorithms for estimating the condition number of boundary value problems and show how this estimate can be used in the grid refinement algorithm. © 2005 Elsevier B.V. All rights reserved

Godunov mixed methods on triangular grids for advection–dispersion equations

A time-splitting approach for advection-dispersion equations is considered. The dispersive and advective fluxes are split into two separate partial differential equations (PDEs), one containing the dispersive term and the other one the advective term. On triangular elements a triangle-based high resolution Finite Volume (FV) scheme for advection is combined with a Mixed Hybrid Finite Element (MHFE) technique to solve dispersion. This approach introduces an error proportional to the time step and the overall scheme is only first order accurate if special care is not taken in the definition of the numerical flux approximation for advection. By incorporating the diffusive effects into the definition of this numerical flux, near second order accuracy (up to a $\log{h}$ factor) can be proved theoretically and validated by numerical experiments in both one and two dimensional cases

DAESA—A Matlab Tool for Structural Analysis of Differential-Algebraic Equations

DAESA, Differential-Algebraic Equations Structural Analyzer, is a MATLAB tool for structural analysis of differential-algebraic equations (DAEs). It allows convenient translation of a DAE system into MATLAB and provides a small set of easy-to-use functions. DAESA can analyze systems that are fully nonlinear, highindex, and of any order. It determines structural index, number of degrees of freedom, constraints, variables to be initialized, and suggests a solution scheme. The structure of a DAE can be readily visualized by this tool. It also can construct a block-triangular form of the DAE, which can be exploited to solve it efficiently in a block-wise manner. This paper describes the theory and algorithms underlying the code

Algorithm 948

DAESA, Differential-Algebraic Equations Structural Analyzer, is a MATLAB tool for structural analysis of differential-algebraic equations (DAEs). It allows convenient translation of a DAE system into MATLAB and provides a small set of easy-to-use functions. DAESA can analyze systems that are fully nonlinear, high- index, and of any order. It determines structural index, number of degrees of freedom, constraints, variables to be initialized, and suggests a solution scheme. The structure of a DAE can be readily visualized by this tool. It can also construct a block-triangular form of the DAE, which can be exploited to solve it efficiently in a block-wise manner

Miniature points in an exceptional early South American context

Miniature points, similar to full-sized types used as hunting weapons, have occasionally been described in North and South America for Late Pleistocene/Early Holocene hunter gatherer societies. They are explained as toys, practice pieces or ceremonial objects. They are an interesting case to use to reflect on how people materialize abstractions, encode visual communication, and develop special practices related to particular places. Here we present six miniature points found at Cerro El Sombrero Cima (Buenos Aires province, Argentina), an early site with an unusual assemblage. Five specimens are fishtail projectile points and the sixth is an undescribed stemmed type. We use relevant theoretical insights and address point life history according to their techno-morphological characteristics, raw material identification and fatty acids and sterols analyses. Finally, these projectile-point miniatures are considered in the context of discard, and their role among early American hunter-gatherers is addressed.Fil: Flegenheimer, Nora. Provincia de Buenos Aires. Municipalidad de Necochea. Museo de Ciencias Naturales de Necochea. Area de Arqueología y Antropología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Weitzel, María Celeste. Provincia de Buenos Aires. Municipalidad de Necochea. Museo de Ciencias Naturales de Necochea. Area de Arqueología y Antropología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Mazzia, Natalia Irene. Provincia de Buenos Aires. Municipalidad de Necochea. Museo de Ciencias Naturales de Necochea. Area de Arqueología y Antropología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentin

Compressive sensing-based correlation plenoptic imaging

Correlation Plenoptic Imaging (CPI) is an innovative approach to plenoptic imaging that tackles the inherent trade-off between image resolution and depth of field. By exploiting the intensity correlations that characterize specific states of light, it extracts information of the captured light direction, enabling the reconstruction of images with increased depth of field while preserving resolution. We describe a novel reconstruction algorithm, relying on compressive sensing (CS) techniques based on the discrete cosine transform and on gradients, used in order to reconstruct CPI images with a reduced number of frames. We validate the algorithm using simulated data and demonstrate that CS-based reconstruction techniques can achieve high-quality images with smaller acquisition times, thus facilitating the practical application of CPI