1,984 research outputs found

    Extended-spectrum beta-lactamases-producing <i>Escherichia coli</i> in common vampire bats <i>Desmodus rotundus</i> and livestock in Peru

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    Antibiotic resistance mediated by bacterial production of extended‐spectrum beta‐lactamase (ESBL) is a global threat to public health. ESBL resistance is most commonly hospital‐acquired; however, infections acquired outside of hospital settings have raised concerns over the role of livestock and wildlife in the zoonotic spread of ESBL‐producing bacteria. Only limited data are available on the circulation of ESBL‐producing bacteria in animals. Here, we report ESBL‐producing Escherichia coli in wild common vampire bats Desmodus rotundus and livestock near Lima, Peru. Molecular analyses revealed that most of this resistance resulted from the expression of blaCTX‐M‐15 genes carried by plasmids, which are disseminating worldwide in hospital settings and have also been observed in healthy children of Peru. Multilocus sequence typing showed a diverse pool of E. coli strains carrying this resistance that were not always host species‐specific, suggesting sharing of strains between species or infection from a common source. This study shows widespread ESBL resistance in wild and domestic animals, supporting animal communities as a potential source of resistance. Future work is needed to elucidate the role of bats in the dissemination of antibiotic‐resistant strains of public health importance and to understand the origin of the observed resistance

    El rol del control personal en la función paliativa de la justificación del sistema entre la población indígena y no indígena de estudiantes peruanos

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    Indexación: Scopus.In this article we propose a mediation model for the association between system justification and psychological well-being (i.e., the palliative function of ideology), based on system justification theory and compensatory control theory. Specifically, we argue that endorsing system-justifying beliefs leads to increased perceived personal control, which in turn predicts higher well-being. We used a convenience sample of students from two Peruvian universities. The results showed that system justification was related to general psychological well-being and personal control. In addition, indigenous students rated lower on system justification, general psychological well-being, self-esteem and personal control. Next, we found that the association between system justification and general psychological well-being was stronger among indigenous students, and this relationship was partially mediated by personal control. In addition, we showed that the mediation model is moderated by ethnicity, so that personal control is a mediator only among non-indigenous participants. We conclude that personal control is a mechanism involved in the palliative function of ideology among this group. Finally, we discuss possible explanations for the mechanisms involved in the palliative function of ideology among low-status individuals. © 2018, © 2018 Fundacion Infancia y Aprendizaje.En este artículo se propone un modelo de mediación de las relaciones entre la justificación del sistema y el bienestar psicológico (i.e., la función paliativa de la ideología) basado en las teorías de la justificación del sistema y del control compensatorio. En concreto, se propone que la adopción de creencias justificativas del sistema produce un aumento del control personal percibido que, a su vez, predice niveles más elevados de bienestar. En este estudio se utilizó una muestra por conveniencia de estudiantes provenientes de dos universidades peruanas. Los resultados muestran que la justificación del sistema está relacionada con el bienestar psicológico general y con el control personal. Además, los estudiantes indígenas mostraron niveles más reducidos de justificación del sistema, bienestar psicológico general, autoestima y control personal. También se observó que la relación entre la justificación del sistema y el bienestar psicológico general era más fuerte entre los estudiantes indígenas y que el control personal mediaba parcialmente en esta relación. Asimismo, mostramos que la etnicidad es un factor moderador del modelo de mediación, por lo que el control personal es un mediador únicamente entre los participantes no indígenas. El estudio concluye que el control personal es un mecanismo que interviene en la función paliativa de la ideología en este grupo. Por último, se discuten posibles explicaciones de los mecanismos implicados en la función paliativa de la ideología entre individuos de estatus social bajo.https://www.tandfonline.com/doi/full/10.1080/02134748.2018.153765

    Extracción con CO2 Supercrítico de Aceite de Semillas de Guanábana (Annona muricata): Cinética, Perfil de Ácidos Grasos y Esteroles

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    Se estudió la extracción de aceite de semillas de guanábana utilizando dióxido de carbono supercrítico a presiones entre 20 y 35 MPa y temperaturas entre 313 y 333 K, con un flujo de dióxido de carbono constante de 30 g.min-1 y un tiempo de extracción de 150 min. Se planteó un diseño experimental compuesto central para estudiar el efecto de la presión (P) y la temperatura (T) sobre el rendimiento, el perfil de ácidos grasos y esteroles. La composición en ácidos grasos y esteroles se analizó por cromatografía de gases. La presión tuvo un efecto significativo (p<0,05) sobre el rendimiento alcanzando un rendimiento óptimo del 12.9%. El ácido oleico es el ácido graso mayoritario, seguido del ácido palmítico y linoleico. En menor proporción se encontraron el ácido esteárico, palmitoleico, linolénico y dodecanoico. Además, se encontró la presencia de campesterol, estigmasterol y β-sitosterol. Por lo tanto, el aceite obtenido libre de solventes muestra potencial para ser usado como ingrediente natural en diferentes industrias

    SU(3)cSU(3)LU(1)XSU(3)_c\otimes SU(3)_L\otimes U(1)_X models with four families

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    In the context of the local gauge group SU(3)cSU(3)LU(1)XSU(3)_c\otimes SU(3)_L\otimes U(1)_X, we look for possible four family models, where all the particles carry ordinary electric charges. Thirteen different anomaly-free fermion structures emerge, out of which only two are realistic. For the simplest physical structure, we calculate the charged and neutral weak currents and the tree-level Fermion masses. We also look for new sources of flavor changing neutral currents in the quark sector, in connection with the upcoming experimental results at the Large Hadron Collider.Comment: Accepted for publication in Phys. Rev.

    Spin Density wave instability in a ferromagnet

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    Ferromagnetic (FM) and incommensurate spin-density wave (ISDW) states are an unusual set of competing magnetic orders that are seldom observed in the same material without application of a polarizing magnetic field. We report, for the first time, the discovery of an ISDW state that is derived from a FM ground state through a Fermi surface (FS) instability in Fe3_3Ga4_4. This was achieved by combining neutron scattering experiments with first principles simulations. Neutron diffraction demonstrates that Fe3_3Ga4_4 is in an ISDW state at intermediate temperatures and that there is a conspicuous re-emergence of ferromagnetism above 360 K. First principles calculations show that the ISDW ordering wavevector is in excellent agreement with a prominent nesting condition in the spin-majority FS demonstrating the discovery of a novel instability for FM metals; ISDW formation due to Fermi surface nesting in a spin-polarized Fermi surface.Comment: 6 pages with 4 figures. Supplemental Materials Include

    Astrobee Guest Science Interface

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    At the end of 2018, Astrobee will launch three free-flying robots that will navigate the entire US segment of the ISS (International Space Station) and serve as a payload facility. The mechanical and electrical interfaces are now established and several payloads are being developed. Payload Interface: Astrobee is designed to host third party guest science program payloads (GSP payloads). Some GSP payloads may be software only, such as the Zero Robotics Finals Competition, which is currently hosted on SPHERES, and which will transition to Astrobee in 2019. Several GSP payloads with custom hardware, such as the Advanced Exploration Systems (AES) Logistics Reduction and Repurposing (LRR) Project RFID reader, are already under development. These payloads will attach in the Astrobee payload bay

    Dominance of unicellular cyanobacteria in the diazotrophic community in the Atlantic Ocean

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    ABSTRACT: The horizontal and vertical distribution of representatives of diazotrophic unicellular cyanobacteria was investigated in the subtropical northeast Atlantic Ocean (28.87 to 42.00°N; 9.01 to 20.02°W). Samples from stations encompassing different water conditions (from oceanic oligotrophic waters to upwelling areas and a temperature range of 13.1°C to 24.2°C) were size fractionated and analyzed for nifH by a nested polymerase chain reaction (PCR) and by tyramide signal amplification–fluorescence in situ hybridization (TSA-FISH) using probe Nitro821. In samples from the surface, mixed-layer depth, and deep chlorophyll maximum waters, most (> 50%) of the nifH recovered was from the 0.2–3 µm fraction and was consistent with TSA-FISH counts. The < 3 µm Nitro821-positive cells were more abundant than the larger cells, and the proportion of single cells was larger than that associated with particulate matter or with larger cells. Phylogenetic analysis of representative samples revealed that most of the sequences belong to diazotrophic unicellular cyanobacteria Group A (UCYN-A or Candidatus Atelocyanobacterium thalassa). N2 fixation in the 0.2–3 µm fraction, putatively representing the activity of UCYN-A, contributed more than 50% of the total N2 fixation. There was a positive relationship of this putative UCYN-A abundance and activity with temperature, and a negative relationship with dissolved O2. The dominance of these putative UCYN-A organisms in nitrate-rich upwelling filament regions suggests that the activity of this group of organisms may not be strongly controlled by the availability of fixed N
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