First report of a South American short-faced bears' den (Arctotherium angustidens): palaeobiological and palaeoecological implications

Here we report the first example of associated short-faced bear fossils from South America. The specimens represent three individuals referable to the Ensenadan (early to middle Pleistocene) species Arctotherium angustidens (Ursidae, Tremarctinae), the giant South American short-faced bear. Although the fossil record of short-faced bears in South America is very rich, they have not previously been recorded in association. These three individuals were found in a cave during quarry exploitation. We suggest that these bears represent the first record of a family group and open the discussion about cave utilization and hibernation or torpor by South American short-faced bears.Museo de La Plat

Multilevel Modeling of Geographic Information Systems Based on International Standards

Financiado para publicación en acceso aberto: Universidade da Coruña/CISUG[Abstract] Even though different applications based on Geographic Information Systems (GIS) provide different features and functions, they all share a set of common concepts (e.g., spatial data types, operations, services), a common architecture, and a common set of technologies. Furthermore, common structures appear repeatedly in different GIS, although they have to be specialized in specific application domains. Multilevel modeling is an approach to model-driven engineering (MDE) in which the number of metamodel levels is not fixed. This approach aims at solving the limitations of a two-level metamodeling approach, which forces the designer to include all the metamodel elements at the same level. In this paper, we address the application of multilevel modeling to the domain of GIS, and we evaluate its potential benefits. Although we do not present a complete set of models, we present four representative scenarios supported by example models. One of them is based on the standards defined by ISO TC/211 and the Open Geospatial Consortium. The other three are based on the EU INSPIRE Directive (territory administration, spatial networks, and facility management). These scenarios show that multilevel modeling can provide more benefits to GIS modeling than a two-level metamodeling approach.Xunta de Galicia; IN852A 2018/14Xunta de Galicia; ED431G 2019/01This work has been partially funded by grants: MICIU/FEDER-UE, MAGIST: PID2019-105221RB-C41; MICIU/FEDER-UEBIZDEVOPSGLOBAL: RTI-2018-098309-B-C32, Xunta de Galicia/FEDER-UE, ConectaPeme, GEMA: IN852A 2018/14; MINECOAEI/FEDER-UE Datos 4.0: TIN2016-78011-C4-1-R; MINECOAEI/FEDER-UE Velocity: TIN2016-77158-C4-3-R; CITIC research center funded by XUNTA and EU through the European Regional Development Fund- Galicia 2014-2020 Program, grant ED431G 2019/01. Funding for open access charge: Universidade da Coruña/CISUG

Validation of a rapid antigen test as a screening tool for SARS-CoV-2 infection in asymptomatic populations. Sensitivity, specificity and predictive values

Background: Early diagnosis of SARS-CoV-2 infection is essential to reduce disease spread. Rapid antigen tests have not been sufficiently evaluated in asymptomatic patients to be used as massive population screening tools. Methods: Head-to-head evaluation of Roche SARS-CoV-2 Rapid Antigen Test and real-time reverse transcription polymerase chain reaction (RT-PCR) as SARS-CoV-2 screening tools performed in asymptomatic adults from a semi-closed community in University of Navarra (Spain) from November 2020 to January 2021. Sensitivity, specificity and predictive values were calculated using RT-PCR as reference method. Findings: Roche SARS-CoV-2 Rapid Antigen Test was performed on 2542 asymptomatic adults in a community with a SARS-CoV-2 incidence of 1·93%. It showed a sensitivity of 71·43% (CI 95%: 56·74 – 83·42) and a specificity of 99·68% (CI 95%: 99·37 - 99·86). Positive Predictive Value was 81·4 (CI 95% 66·6 – 91·61) and Negative Predictive Value was 99·44 (CI 95% 99·06 – 99·69). Test sensitivity was related to viral load, with higher sensitivity in RT-PCR cycle threshold (Ct) values under 25 (93·75%, CI 95%: 71·96 – 98·93), that dropped to 29·41% (CI 95%: 10·31- 55·96) in RT-PCR Ct values above 25. Interpretation: This study suggests that rapid antigen tests are less effective in asymptomatic population, when compared with RT-PCR. Further studies are needed to evaluate different options to improve screenings based on rapid antigen test, such as the use of clinical questionnaires to select higher risk-participants, the confirmation of negative results with RT-PCR or the use of repetitive sequential testing

A classical simulation of nonlinear Jaynes-Cummings and Rabi models in photonic lattices

The interaction of a two-level atom with a single-mode quantized field is one of the simplest models in quantum optics. Under the rotating wave approximation, it is known as the Jaynes-Cummings model and without it as the Rabi model. Real-world realizations of the Jaynes-Cummings model include cavity, ion trap and circuit quantum electrodynamics. The Rabi model can be realized in circuit quantum electrodynamics. As soon as nonlinear couplings are introduced, feasible experimental realizations in quantum systems are drastically reduced. We propose a set of two photonic lattices that classically simulates the interaction of a single two-level system with a quantized field under field nonlinearities and nonlinear couplings as long as the quantum optics model conserves parity. We describe how to reconstruct the mean value of quantum optics measurements, such as photon number and atomic energy excitation, from the intensity and from the field, such as von Neumann entropy and fidelity, at the output of the photonic lattices. We discuss how typical initial states involving coherent or displaced Fock fields can be engineered from recently discussed Glauber-Fock lattices. As an example, the Buck-Sukumar model, where the coupling depends on the intensity of the field, is classically simulated for separable and entangled initial states

Rare Events and Scale--Invariant Dynamics of Perturbations in Delayed Dynamical Systems

We study the dynamics of perturbations in time delayed dynamical systems. Using a suitable space-time coordinate transformation, we find that the time evolution of the linearized perturbations (Lyapunov vector) can be mapped to the linear Zhang surface growth model [Y.-C. Zhang, J. Phys. France {\bf 51}, 2129 (1990)], which is known to describe surface roughening driven by power-law distributed noise. As a consequence, Lyapunov vector dynamics is dominated by rare random events that lead to non-Gaussian fluctuations and multiscaling properties.Comment: Final version to appear in Phys. Rev. Lett., 4 pages, 3 eps fig

Evidence for helical microstructure of aragonite fibers in pteropod shells

Planktonic gastropods of the suborder Euthecosomata (order Pteropoda) secrete a unique microstructure made of tightly interlocked, space-filling helically coiled aragonite fibers. This material has a high degree of ordering because all fibers are in phase at a given growth plane. The recognition of the helical nature from mere scanning electron micrographs is somewhat uncertain. In addition, threedimensional (3D) reconstructions of individual helices are hindered by the small dimensions of fibers, and the virtual absence of intervening organic interphases. Here, we (1) reexamine the morphological characteristics of the fibers in fracture and find them compatible with a helical model, (2) provide direct evidence of the helical mode of coiling in the form of anaglyphs, and (3) develop a 3D model, which is fully consistent with the patterns observed in fractures and polished sections. Proposals based on motifs different from helices are not congruent with the observations.Universidad de Granada/CBUAMinistry of Science and Innovation, Spain (MICINN)Instituto de Salud Carlos III Spanish Government CGL2017-85118-P PID2020-116660 GB-I00 Junta de Andalucia B-RNM-265-UGR18 PCIN-2017-098 RNM363Polish National Agency for Academic Exchange (NAWA) KB PPI/APM/2018/1/00049/U/001Unidad Cientifica de Excelencia UCE-PP2016-05University of GranadaEuropean COST Action CA17120Ministry of Science and Innovation, Spain (MICINN) Spanish Government FJC2018-035820-ISKA South Africa 844345Malacological Society of London Travel Awar

Catálogo de las orquídeas del Valle geográfico del río Cauca y su piedemonte andino bajo, Sur-occidente colombiano.

Twenty forest patches belonging to the potential domain of tropical dry forest were explored in the Cauca Valley bioregion (421,000 ha) in southwestern Colombia. Sampling was carried out from September, 2009,to October, 2010, at elevations between 930 and 1,200 m. During the field evaluations we reach 346 hours of observation distributed in 60 Km. This exploration produced the most complete list of orchids ever made in this territory, with a total of 70 species belonging to 41 genera. This figure is 112% (37 species) greater than existing records for this bioregion, and represents 1.74% of the total of orchid species reported for Colombia. Several new regional records were found, as well as at least three endemic species, probably one local extinction, and one new species for science. This figure is compared with other much smaller areas, such as the forest of Yotoco in the department of Valle del Cauca, and possible explanations for the low species richness are proposed. At the same time, a bank of digital high-resolution images of the orchid flora of the department was begun

PTGER4 gene variant rs76523431 is a candidate risk factor for radiological joint damage in rheumatoid arthritis patients: a genetic study of six cohorts

[Introduction] Prostaglandin E receptor 4 (PTGER4) is implicated in immune regulation and bone metabolism. The aim of this study was to analyze its role in radiological joint damage in rheumatoid arthritis (RA).[Methods] Six independent cohorts of patients with RA of European or North American descent were included, comprising 1789 patients with 5083 sets of X-rays. The Hospital Clínico San Carlos Rheumatoid Arthritis, Princesa Early Arthritis Register Longitudinal study, and Hospital Universitario de La Paz early arthritis (Spain) cohorts were used as discovery cohorts, and the Leiden Early Arthritis Clinic (The Netherlands), Wichita (United States), and National Databank for Rheumatic Diseases (United States and Canada) cohorts as replication cohorts. First, the PTGER4 rs6896969 single-nucleotide polymorphism (SNP) was genotyped using TaqMan assays and available Illumina Immunochip data and studied in the discovery and replication cohorts. Second, the PTGER4 gene and adjacent regions were analyzed using Immunochip genotyping data in the discovery cohorts. On the basis of pooled p values, linkage disequilibrium structure of the region, and location in regions with transcriptional properties, SNPs were selected for replication. The results from discovery, replication, and overall cohorts were pooled using inverse-variance–weighted meta-analysis. Influence of the polymorphisms on the overall radiological damage (constant effect) and on damage progression over time (time-varying effect) was analyzed.[Results] The rs6896969 polymorphism showed a significant association with radiological damage in the constant effect pooled analysis of the discovery cohorts, although no significant association was observed in the replication cohorts or the overall pooled analysis. Regarding the analysis of the PTGER4 region, 976 variants were analyzed in the discovery cohorts. From the constant and time-varying effect analyses, 12 and 20 SNPs, respectively, were selected for replication. Only the rs76523431 variant showed a significant association with radiographic progression in the time-varying effect pooled analysis of the discovery, replication, and overall cohorts. The overall pooled effect size was 1.10 (95 % confidence interval 1.05–1.14, p = 2.10 × 10−5), meaning that radiographic yearly progression was 10 % greater for each copy of the minor allele.[Conclusions] The PTGER4 gene is a candidate risk factor for radiological progression in RA.This work was supported by the Instituto de Salud Carlos III (ISCIII), Ministry of Health, Spain [Miguel Servet research contract CP12/03129 (to LRR); Fondo de Investigaciones Sanitarias PI11/02413; and Red de Investigación en Inflamación y Enfermedades Reumáticas RD12/0009/0004, RD12/0009/0011, and RD12/0009/0017]. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewe

Efecto del NaCl sobre los parámetros de crecimiento, rendimiento y calidad de la cebolla de bulbo (Allium cepa L.) bajo condiciones controladas

El experimento se realizó en el primer semestre de 2010 en los invernaderos de la Facultad de Agronomía, Universidad Nacional de Colombia, Bogotá, con temperatura y humedad relativa promedio de 21°C y 60%, respectivamente. Se evaluó el efecto de concentraciones crecientes en el agua de riego de 0, 30, 60 y 90 mM de NaCl (conductividad eléctrica de 0, 3, 6 y 9 ±0,2 dS m-1, respectivamente) sobre parámetros de crecimiento, rendimiento y calidad en cebolla de bulbo, var. Yellow Granex, en un diseño completamente aleatorizado con cuatro repeticiones. Los niveles salinos crecientes generaron un desarrollo precoz, expresado en acumulación rápida de materia seca (MS) en los primeros estados de crecimiento, teniendo implicaciones fisiológicas en el desarrollo del bulbo. Se presentaron diferencias significativas a partir de la etapa de desarrollo del bulbo para las variables altura, número de hojas y diámetro del pseudotallo de la planta. Asimismo, se registraron reducciones respecto al tratamiento control de 31%, 53% y 70% de MS total, 44%, 53% y 71% de MS de la parte aérea, 28%, 49% y 74% de MS del bulbo, 12%, 25% y 43% para el diámetro y 30%, 52% y 78% para el peso fresco del bulbo en los niveles crecientes de 30, 60 y 90 mM de NaCl, respectivamente. Los niveles salinos crecientes se relacionaron directamente con el aumento en los valores de sólidos solubles totales y disminución en el contenido de ácido pirúvico, lo que se tradujo en un sabor más dulce y menos pungente de los bulbos.Cebolla de bulbo-Cebolla japonesa