353 research outputs found

    Contrasting human perceptions of and attitudes towards two threatened small carnivores, Lycalopex fulvipes and Leopardus guigna, in rural communities adjacent to protected areas in Chile

    Get PDF
    Indexación: Scopus.The interaction between humans and small carnivores is a phenomenon especially frequent in rural fringes, as is the case of communities surrounding natural areas. In Chile, two species of threatened carnivores, the Darwin's Fox and the Guigna, have increased their contact with humans due to human-induced changes in their habitat. The objective of this study was to characterize the interactions of these species with humans by assessing human perceptions and attitudes toward them, and to assess livestock and poultry ownership and management practices in local communities to evaluate their possible roles in the phenomenon. We conducted semi-structured interviews in rural communities adjacent to natural protected areas of two different regions in southern Chile. We found that people have a more positive perception of Darwin's Foxes than Guignas, but both species are considered damaging due to poultry attacks. Livestock and poultry management was generally deficient. Improvements in animal management and education programs could lead to a significant decrease in negative interactions. © Sacristan et al. 2018.https://www.threatenedtaxa.org/index.php/JoTT/article/view/4030/442

    On the Integration of Grassmannian Constellations into LTE Networks: a Link-level Performance Study

    Get PDF
    This paper presents Grassmannian signaling as a transmission scheme that can be integrated in Long Term Evolution (LTE) to support higher user speeds and to increase the throughput achievable in the high Signal to Noise Ratio (SNR) regime. This signaling is compared, under realistic channel assumptions, with the diversity transmission modes standardized in LTE, in particular, Space-Frequency Block Coding and Frequency-Switched Transmit Diversity for two and four transmit antennas, respectively. In high-speed scenarios, and even with high antenna correlation, Grassmannian signaling outperforms the LTE diversity transmission modes starting from four transmit antennas. Furthermore, in the high SNR regime, Grassmannian signaling can increase the link data rate up to 10% and 15% for two and four antennas, respectively

    A link between nuclear RNA surveillance, the human exosome and RNA polymerase II transcriptional termination

    Get PDF
    In eukaryotes, the production of mature messenger RNA that exits the nucleus to be translated into protein in the cytoplasm requires precise and extensive modification of the nascent transcript. Any failure that compromises the integrity of an mRNA may cause its retention in the nucleus and trigger its degradation. Multiple studies indicate that mRNAs with processing defects accumulate in nuclear foci or ‘dots’ located near the site of transcription, but how exactly are defective RNAs recognized and tethered is still unknown. Here, we present evidence suggesting that unprocessed β-globin transcripts render RNA polymerase II (Pol II) incompetent for termination and that this quality control process requires the integrity of the nuclear exosome. Our results show that unprocessed pre-mRNAs remain tethered to the DNA template in association with Pol II, in an Rrp6-dependent manner. This reveals an unprecedented link between nuclear RNA surveillance, the exosome and Pol II transcriptional termination

    Eosinophilic Panniculitis and Insect Bite-Like Eruption in a Patient with Chronic Lymphocytic Leukaemia: A Spectrum of the Same Entity

    Get PDF
    Background. Eosinophilic dermatosis of hematologic disorders is a reactive process that may cause a variety of clinical manifestations. Methods. We report a patient who had outbreaks of skin lesions since the onset of chronic lymphocytic leukaemia. Results. The cutaneous eruptions began as eosinophilic panniculitis and after changed to insect bite-like lesions. Conclusion. We think that eosinophilic panniculitis and insect bite-like lesions may be part of the spectrum of the same entity in patients with hematologic disorders

    Map-Based Channel Model for Urban Macrocell Propagation Scenarios

    Get PDF
    The evolution of LTE towards 5G has started and different research projects and institutions are in the process of verifying new technology components through simulations. Coordination between groups is strongly recommended and, in this sense, a common definition of test cases and simulation models is needed. The scope of this paper is to present a realistic channel model for urban macrocell scenarios. This model is map-based and takes into account the layout of buildings situated in the area under study. A detailed description of the model is given together with a comparison with other widely used channel models. The benchmark includes a measurement campaign in which the proposed model is shown to be much closer to the actual behavior of a cellular system. Particular attention is given to the outdoor component of the model, since it is here where the proposed approach is showing main difference with other previous models

    Occurrence and Quantification of Antimicrobial Resistance Genes in the Gastrointestinal Microbiome of Two Wild Seabird Species With Contrasting Behaviors

    Get PDF
    Indexación ScopusAntimicrobial resistance genes (ARGs) are environmental pollutants and anthropization indicators. We evaluated human interference in the marine ecosystem through the ocurrence and quantification (real-time PCRs) of 21 plasmid-mediated ARGs in enema samples of 25 wild seabirds, upon admission into rehabilitation: kelp gull (Larus dominicanus, n = 14) and Magellanic penguin (Spheniscus magellanicus, n = 11). Overall, higher resistance values were observed in kelp gulls (non-migratory coastal synanthropic) in comparison with Magellanic penguins (migratory pelagic non-synanthropic). There were significant differences between species (respectively, kelp gull and Magellanic penguin): ARGs occurrence (blaTEM [p = 0.032]; tetM [p = 0.015]; tetA [p = 0.003]; and sulII [p = 0.007]), mean number of ARGs per sample (p = 0.031), ARGs mean load percentage (aadA [p = 0.045], tetA [p = 0.031], tetM [p = 0.016], blaTEM [p = 0.032], sulII [p = 0.008]), percentage of genes conferring resistance to an antimicrobial class (betalactams [p = 0.036] and sulfonamides [p = 0.033]), mean number of genes conferring resistance to one or more antimicrobial classes (p = 0.024]), percentage of multiresistant microbiomes (p = 0.032), and clustering (p = 0.006). These differences are likely due to these species' contrasting biology and ecology - key factors in the epidemiology of ARGs in seabirds. Additionally, this is the first report of mecA in seabirds in the Americas. Further studies are necessary to clarify the occurrence and diversity of ARGs in seabirds, and their role as potential sources of infection and dispersal within the One Health chain of ARGs. © Copyright © 2021 Ewbank, Esperón, Sacristán, Sacristán, Neves, Costa-Silva, Antonelli, Rocha Lorenço, Kolesnikovas and Catão-Dias.https://www.frontiersin.org/articles/10.3389/fvets.2021.651781/ful

    World Health Organization critical priority Escherichia coli clone ST648 in magnificent frigatebird (Fregata magnificens) of an uninhabited insular environment

    Get PDF
    Antimicrobial resistance is an ancient natural phenomenon increasingly pressured by anthropogenic activities. Escherichia coli has been used as markers of environmental contamination and human-related activity. Seabirds may be bioindicators of clinically relevant bacterial pathogens and their antimicrobial resistance genes, including extended-spectrum-beta-lactamase (ESBL) and/or plasmid-encoded AmpC (pAmpC), in anthropized and remote areas. We evaluated cloacal swabs of 20 wild magnificent frigatebirds (Fregata magnificens) of the Alcatrazes Archipelago, the biggest breeding colony of magnificent frigatebirds in the southern Atlantic and a natural protected area with no history of human occupation, located in the anthropized southeastern Brazilian coast. We characterized a highly virulent multidrug-resistant ST648 (O153:H9) pandemic clone, harboring bla, bla, qnrB, tetB, sul1, sul2, aadA1, aac(3)-VIa and mdfA, and virulence genes characteristic of avian pathogenic (APEC) (hlyF, iroN, iss, iutA, and ompT) and other extraintestinal E. coli (ExPEC) (chuA, kpsMII, and papC). To our knowledge, this is the first report of ST648 E. coli co-producing ESBL and pAmpC in wild birds inhabiting insular environments. We suggest this potentially zoonotic and pathogenic lineage was likely acquired through indirect anthropogenic contamination of the marine environment, ingestion of contaminated seafood, or by intra and/or interspecific contact. Our findings reinforce the role of wild birds as anthropization sentinels in insular environments and the importance of wildlife surveillance studies on pathogens of critical priority classified by the World Health Organization

    GaAs/GaP quantum dots: Ensemble of direct and indirect heterostructures with room temperature optical emission

    Get PDF
    Producción CientíficaWe describe the optical emission and the carrier dynamics of an ensemble of self-assembled GaAs quantum dots embedded in GaP(001). The QD formation is driven by the 3.6% lattice mismatch between GaAs and GaP in the Stranski-Krastanow mode after deposition of more than 1.2 monolayers of GaAs. The quantum dots have an areal density between 6 and 7.6 × 1010 per cm−2 and multimodal size distribution. The luminescence spectra show two peaks in the range of 1.7 and 2.1 eV. The samples with larger quantum dots have red emission and show less thermal quenching compared with the samples with smaller QDs. The large QDs luminescence up to room temperature. We attribute the high energy emission to indirect carrier recombination in the thin quantum wells or small strained quantum dots, whereas the low energy red emission is due to the direct electron-hole recombination in the relaxed quantum dots.Comisión Europea (project FP7-ICT-2013-613024-GRASP

    Cross-species transmission of retroviruses among domestic and wild felids in human-occupied landscapes in Chile

    Get PDF
    Human transformation of natural habitats facilitates pathogen transmission between domestic and wild species. The guigna (Leopardus guigna), a small felid found in Chile, has experienced habitat loss and an increased probability of contact with domestic cats. Here, we describe the interspecific transmission of feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) between domestic cats and guignas and assess its correlation with human landscape perturbation. Blood and tissue samples from 102 free-ranging guignas and 262 domestic cats were collected and analyzed by PCR and sequencing. Guigna and domestic cat FeLV and FIV prevalence were very similar. Phylogenetic analysis showed guigna FeLV and FIV sequences are positioned within worldwide domestic cat virus clades with high nucleotide similarity. Guigna FeLV infection was significantly associated with fragmented landscapes with resident domestic cats. There was little evidence of clinical signs of disease in guignas. Our results contribute to the understanding of the implications of landscape perturbation and emerging diseases
    corecore