Microstratigraphy of shell middens of Tierra del Fuego

The results of the joint research of Spanish and Argentinean teams since 1986 on shell middens of Tierra del Fuego can be useful guidelines for excavating and explaining similar archaeological sites around the world. We assume that human activity is organized in space and time and, as a consequence the random, non-random or homogeneous structure the resulting archaeological evidence has to be demonstrated before assuming a palimpsest nature of the deposit. We show the possibilities and relevance of recovering microstratigraphy of shell middens and discuss the need of using sampling methods that cover a wide surface of short discrete occupation episodes.Después de más de veinte años de investigaciones en el Canal Beagle (Tierra del Fuego) pensamos que puede ser de utilidad presentar nuestros resultados en relación a la metodología de excavación de los yacimientos de la zona, los conocidos como "concheros". La metodología presentada aquí es el producto del ensayo de validación de la hipótesis sobre el carácter de palimpsesto de estas acumulaciones. La aplicación sistemática de un conjunto específico de técnicas nos ha permitido evaluar positivamente la importancia de recuperar la microestratigrafía y desarrollar un sistema de muestreo extensivo para las superficies de ocupación

Trajectory-Based, Probabilistic Risk Model for UAS Operations

To enable the safe integration of Unmanned Aircraft System (UAS) into the civil airspace, the European Aviation Safety Agency (EASA) has elaborated a new regulatory framework that is operation-centric and risk-based. Based on this principle, gaining authorization to conduct certain types of operations depends on a safety risk assessment. To harmonize this process, the Joint Authorities for Rulemaking on Unmanned Systems (JARUS) released a qualitative methodology called Specific Operation Risk Assessment (SORA). However, SORA is not a complete safety assessment tool since, in some cases, a quantitative risk analysis is still required. This work develops a probabilistic risk model that extends SORA to evaluate the ground risk and the air risk components along a specified UAS trajectory quantitatively. The proposed model is supplied with illustrative data and is validated in a representative UAS mission. In the future, the risk model will be exploited to develop a decision tool for determining the minimum-risk trajectory when multiple, alternative routes are available

Evolució de la condició física en jugadores d’handbol en les categories infantil, cadet i juvenil

En aquesta investigació s’analitza la condició física de 91 jugadores d’handbol, amb edats compreses entre els 13 i els 18 anys, distribuïdes en tres categories diferents, infantil (n = 30), cadet (n = 32) i juvenil (n = 29). La investigació té caràcter descriptiu i transversal. El principal objectiu és analitzar l’estructura condicional de les jugadores. Per a la valoració es va aplicar la bateria Eurofit, la bateria de Bosco i test d’Abalakov. Es van trobar diferències significatives entre la categoria infantil-cadet en cinc de les 14 variables estudiades, i cap entre la categoria cadet-juvenil. Els millors resultats es van produir en la categoria juvenil. En general, les restants variables sempre van assolir millors valors que la població escolar (en aquelles variables en les quals la comparança va ser possible), però pitjors que els valors presentats per les jugadores de les seleccions espanyoles. En les proves que van valorar la força del tren inferior, els resultats indiquen que a major categoria les diferències són menors entre categories

Evolución de la condición física en jugadoras de balonmano en las categorías infantil, cadete y juvenil

En la presente investigación se analiza la condición física de 91 jugadoras de balonmano, con edades comprendidas entre 13 y 18 años, distribuidas en tres categorías diferentes, infantil (n = 30), cadete (n = 32) y juvenil (n = 29). La investigación tiene carácter descriptivo y transversal. El principal objetivo es analizar la estructura condicional de las jugadoras. Para su valoración se aplicó la batería Eurofit, la batería de Bosco y test de Abalakov. Se encontraron diferencias significativas entre la categoría infantil-cadete en cinco de las 14 variables estudiadas, y ninguna entre la categoría cadete-juvenil. Los mejores resultados se produjeron en la categoría juvenil. En general, las restantes variables siempre alcanzaron mejores valores que la población escolar (en aquellas variables en las que la comparación fue posible), pero peores que los valores presentados por las jugadoras de las selecciones españolas. En las pruebas que valoraron la fuerza de tren inferior, los resultados indican que a mayor categoría las diferencias son menores entre categorías

Protein determinants of dissemination and host specificity of metallo-β-lactamases

The worldwide dissemination of metallo-β-lactamases (MBLs), mediating resistance to carbapenem antibiotics, is a major public health problem. The extent of dissemination of MBLs such as VIM-2, SPM-1 and NDM among Gram-negative pathogens cannot be explained solely based on the associated mobile genetic elements or the resistance phenotype. Here, we report that MBL host range is determined by the impact of MBL expression on bacterial fitness. The signal peptide sequence of MBLs dictates their adaptability to each host. In uncommon hosts, inefficient processing of MBLs leads to accumulation of toxic intermediates that compromises bacterial growth. This fitness cost explains the exclusion of VIM-2 and SPM-1 from Escherichia coli and Acinetobacter baumannii, and their confinement to Pseudomonas aeruginosa. By contrast, NDMs are expressed without any apparent fitness cost in different bacteria, and are secreted into outer membrane vesicles. We propose that the successful dissemination and adaptation of MBLs to different bacterial hosts depend on protein determinants that enable host adaptability and carbapenem resistance.Fil: López, Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Ayala, Juan A.. Consejo Superior de Investigaciones Científicas; España. Universidad Autónoma de Madrid; EspañaFil: Bonomo, Robert A.. Louis Stokes Cleveland Department of Veterans Affairs Medical Center; Estados Unidos. Case Western Reserve University; Estados Unidos. Center for Antimicrobial Resistance and Epidemiology; Estados UnidosFil: Gonzalez, Lisandro Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; ArgentinaFil: Vila, Alejandro Jose. Center for Antimicrobial Resistance and Epidemiology; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas; Argentin

Paper-based chromatic toxicity bioassay by analysis of bacterial ferricyanide reduction

Water quality assessment requires a continuous and strict analysis of samples to guarantee compliance with established standards. Nowadays, the increasing number of pollutants and their synergistic effects lead to the development general toxicity bioassays capable to analyse water pollution as a whole. Current general toxicity methods, e.g. Microtox®, rely on long operation protocols, the use of complex and expensive instrumentation and sample pre-treatment, which should be transported to the laboratory for analysis. These requirements delay sample analysis and hence, the response to avoid an environmental catastrophe. In an attempt to solve it, a fast (15 min) and low-cost toxicity bioassay based on the chromatic changes associated to bacterial ferricyanide reduction is here presented. E. coli cells (used as model bacteria) were stably trapped on low-cost paper matrices (cellulose-based paper discs, PDs) and remained viable for long times (1 month at -20 °C). Apart from bacterial carrier, paper matrices also acted as a fluidic element, allowing fluid management without the need of external pumps. Bioassay evaluation was performed using copper as model toxic agent. Chromatic changes associated to bacterial ferricyanide reduction were determined by three different transduction methods, i.e. (i) optical reflectometry (as reference method), (ii) image analysis and (iii) visual inspection. In all cases, bioassay results (in terms of half maximal effective concentrations, EC50) were in agreement with already reported data, confirming the good performance of the bioassay. The validation of the bioassay was performed by analysis of real samples from natural sources, which were analysed and compared with a reference method (i.e. Microtox). Obtained results showed agreement for about 70% of toxic samples and 80% of non-toxic samples, which may validate the use of this simple and quick protocol in the determination of general toxicity. The minimum instrumentation requirements and the simplicity of the bioassay open the possibility of in-situ water toxicity assessment with a fast and low-cost protocolPostprint (author's final draft

A CTMC-based characterisation of the propagation of errors in GMPLS Optical Rings

Abstract: This article presents a Continuous-Time Markov Chain model to characterise the propagation of failures in optical GMPLS rings. In order to characterize the behaviour of failure propagation epidemic-based models are commonly used. However, the existing epidemic models do not take into account the specific features of a multilayer network environment. A node failure in GMPLS-based networks can affect: Control Plane and Data plane reporting different failures scenarios. Consequently, an extended generic epidemic model called SID is proposed, in order to cover multiple failures and recovered states in a GMPLS Multilayer scenario. The CTMC model takes into account the SID model and provides a set of design rules to specify the values of repair rates required to achieve a given service availability, assuming a certain infection and disable rate.The work described in this paper was carried out with the support of the BONE project (''Building the Future Optical Network in Europe''), a Network of Excellence funded by the European Commission through the 7th ICT-Framework Programme. Additionally, the authors would like to thank the support of the T2C2 Spanish project (under code TIN2008-06739-C04-01) and the Madrid Community through the MEDIANET project (S-2009/TIC-1468) to the development of this work. This work is partially supported by Spanish Ministry of Science and Innovation project TEC 2009-10724 and by Generalitat de Catalunya research support program (SGR-1202).Publicad

Two-step approach for occupancy estimation in intensive care units based on Bayesian optimization techniques

Due to the high occupational pressure suffered by intensive care units (ICUs), a correct estimation of the patients’ length of stay (LoS) in the ICU is of great interest to predict possible situations of collapse, to help healthcare personnel to select appropriate treatment options and to predict patients’ conditions. There has been a high amount of data collected by biomedical sensors during the continuous monitoring process of patients in the ICU, so the use of artificial intelligence techniques in automatic LoS estimation would improve patients’ care and facilitate the work of healthcare personnel. In this work, a novel methodology to estimate the LoS using data of the first 24 h in the ICU is presented. To achieve this, XGBoost, one of the most popular and efficient state-of-the-art algorithms, is used as an estimator model, and its performance is optimized both from computational and precision viewpoints using Bayesian techniques. For this optimization, a novel two-step approach is presented. The methodology was carefully designed to execute codes on a high-performance computing system based on graphics processing units, which considerably reduces the execution time. The algorithm scalability is analyzed. With the proposed methodology, the best set of XGBoost hyperparameters are identified, estimating LoS with a MAE of 2.529 days, improving the results reported in the current state of the art and probing the validity and utility of the proposed approach.Agencia Gallega de Innovación | Ref. IN845D-2020/29Agencia Gallega de Innovación | Ref. IN607B-2021/1

Dynamic model of a railway wheelset for corrugation problem analysis

[EN] In the present work a model of flexible shafts is adapted for modelling the railway wheelset. The dynamic properties of the solid are obtained from a solid finite element model of a real wheelset. The model adopts an Eulerian coordinate set for numerical efficiency. Results of the crossed-receptance and mobility functions are presented, where the excitation is the vertical wheel-rail contact force and the displacement (or velocity) is measured in the wheel-rail contact plane. These results let us know that the gyroscopic effect may contribute to define the wavelength-fixing mechanism in some corrugation problems, even if the train speed is low.This work was sponsored by Projects T79/2006 (Ministerio de Fomento - Metro de Madrid- CDM) and TRA2007-67167 (Ministerio de Educación y Ciencia - FEDER).Vila Tortosa, MP.; Rovira, A.; Fayos Sancho, J.; Baeza González, LM. (2009). Dynamic model of a railway wheelset for corrugation problem analysis. Noise & Vibration Worldwide. 40(11):10-18. https://doi.org/10.1260/095745609790251579S1018401