60 research outputs found

    Fitodepuración mixotrófica en sistemas de recirculación acuícola (RAS) para el manejo sustentable de nutrientes contaminantes

    Get PDF
    Industrial aquaculture has grown rapidly due to the increase in world demand for fish and shellfish, which has stimulated the development of aquaculture systems for the cultivation of marine species. The need to maintain high levels of productivity makes them complex unstable systems, prone to disturbances with the potential risk of causing problems of contamination of the natural environment. In intensive aquaculture operations, it is estimated that in the transformation processes for the development and growth of biomass, approximately 75% of the feed is released in the form of nitrogen and phosphorus. During the last decades, efforts have been made to develop processes for the elimination of these nutrients-pollutants, which would otherwise be released into natural water bodies causing eutrophication. The recirculating aquaculture system (RAS) is the conventional culture system; it includes a nutrient removal stage with biofilters of aerobic bacteria that favor the nitrification process, although the biofilter technology has operational difficulties such as the decrease in oxygen concentration, accumulation of organic matter and difficulty of back-rinsing, among others. Thus, options have emerged based on the activity of photoautotrophic organisms, taking advantage of the ability of aquatic plants, macro and microalgae, to effectively eliminate nutrients-pollutants (phytodepuration), consuming in addition to carbon and nitrogen, also phosphorus, the latter without the ability to be removed with nitrifying biofilters. However, this treatment strategy has not been used in intensive aquaculture due to the high availability of the area in demand, which exceeds that required by compact equipment for nitrifying biofiltration. Mixotrophic phytodepuration, which corresponds to the integration of two tertiary wastewater treatment technologies (biofiltration-autotrophic and phytodepuration), could be an efficient response for the treatment of aquaculture wastewater, given the interaction between the organisms involved. For this reason, this review focuses on the potential use of mixotrophic cultivation for the control of nutrients-pollutants in "RAS" or aquaculture wastewater, in addition to contributing to the development of circular economy.La acuicultura industrial ha crecido rápidamente debido al aumento en la demanda mundial de pescados y mariscos, lo que ha estimulado el desarrollo de sistemas acuícolas de cultivo de especies marinas. La necesidad de mantener altos niveles de productividad los convierte en sistemas complejos e inestables, propensos a sufrir perturbaciones con riesgo potencial de causar problemas de contaminación del ambiente natural. En las operaciones de acuicultura intensiva se estima que en los procesos de transformación para el desarrollo y crecimiento de la biomasa, aproximadamente el 75% del alimento es liberado en forma de nitrógeno y fósforo. Durante las últimas décadas se han realizado esfuerzos para el desarrollo de procesos de eliminación de estos nutrientes-contaminantes, que de otra manera serían liberados a los cuerpos de agua natural, causando eutrofización. El sistema de acuicultura con recirculación (RAS) es el sistema convencional de cultivo; incluye una etapa de remoción de nutrientes con biofiltros de bacterias aerobias que favorecen el proceso de nitrificación, aunque la tecnología de biofiltros tiene dificultades operacionales tales como la disminución en la concentración de oxígeno, acumulación de materia orgánica y dificultad de retroenjuague, entre otras. Así, han surgido opciones basadas en la actividad de organismos fotoautotróficos aprovechando la capacidad de plantas acuáticas, macro y microalgas, de eliminar con eficacia nutrientes-contaminantes (fitodepuración), consumiendo además de carbono y nitrógeno, también el fosforo, este último sin capacidad de ser removido con biofiltros nitrificantes. Sin embargo, esta estrategia de tratamiento no se ha utilizado en acuicultura intensiva debido a la alta disponibilidad de superficie demandada y que supera la requerida por los compactos equipos de para biofiltración nitrificante. La fitodepuración mixotrófica, que corresponde a la integración de dos tecnologías de tratamiento terciario de aguas residuales (biofiltración-autotrófica y fitodepuración), podrían ser una respuesta eficiente para el tratamiento de aguas residuales acuícolas, dada la interacción entre los organismos involucrados. Por ello, esta revisión se enfoca al potencial uso de los cultivos mixotróficos para el control de nutrientes-contaminantes en “RAS” o aguas residuales acuícolas, además de aportar al desarrollo de economía circular

    A methodology for probabilistic assessment of solar thermal power plants yield

    Get PDF
    AIP Conference Proceedings 1850, 140006-1–140006-7A detailed knowledge of the solar resource is a critical point to perform an economic feasibility analysis of Concentrating Solar Power (CSP) plants. This knowledge must include its magnitude (how much solar energy is available at an area of interest over a long time period), and its variability over time. In particular, DNI inter-annual variations may be large, increasing the return of investment risk in CSP plant projects. This risk is typically evaluated by means of the simulation of the energy delivered by the CSP plant during years with low solar irradiation, which are typically characterized by annual solar radiation datasets with high probability of exceedance of their annual DNI values. In this context, this paper proposes the use meteorological years representative of a given probability of exceedance of annual DNI in order to realistically assess the inter-annual variability of energy yields. The performance of this approach is evaluated in the location of Burns station (University of Oregon Solar Radiation Monitoring Laboratory), where a 34- year (from 1980 to 2013) measured data set of solar irradiance and temperature is available

    Experimental demonstration of a magnetically induced warping transition in a topological insulator mediated by rare-earth surface dopants

    Get PDF
    Magnetic topological insulators (MTI) constitute a novel class of materials where the topologically protected band structure coexists with long-range ferromagnetic order, which can lead to the breaking of time-reversal symmetry (TRS), introducing a bandgap in the Dirac cone-shaped topological surface state (TSS). The gap opening in MITs has been predicted to be accompanied by a distortion in the TSS, evolving its warped shape from hexagonal to trigonal. In this work, we demonstrate such a transition by means of angle-resolved photoemission spectroscopy after the deposition of low concentrations of magnetic rare earths, namely Er and Dy, on the ternary three-dimensional prototypical topological insulator Bi2_2Se2_2Te. Signatures of the gap opening occurring as a consequence of the TRS breaking have also been observed, whose existence is supported by the observation of the aforementioned transition. Moreover, increasing the Er coverage results in a tunable p-type doping of the TSS. As a consequence, the Fermi level (EF_{\textrm{F}}) of our Bi2_2Se2_2Te crystals can be gradually tuned towards the TSS Dirac point, and therefore to the magnetically induced bandgap; thus fulfilling two of the necessary prerequisites for the realization of the quantum anomalous Hall effect (QAHE) in this system. The experimental results are rationalized by a theoretical model where a magnetic Zeeman out-of-plane term is introduced in the hamiltonian governing the TSS band dispersion. Our results offer new strategies to control magnetic interactions with TSSs based on a simple approach and open up viable routes for the realization of the QAHE

    Seroepidemiology of Toxoplasma gondii infection in psychiatric inpatients in a northern Mexican city

    Get PDF
    BACKGROUND: Patients with psychiatric disorders were found to show a high seroprevalence of Toxoplasma gondii infection. There is scarce information about the epidemiology of T. gondii infection in psychiatric patients in Mexico. Therefore, we sought to determine the prevalence of T. gondii infection and associated socio-demographic, clinical and behavioural characteristics in a population of psychiatric patients in Durango City, Mexico. Seroprevalence in patients was compared with that obtained in a control population. METHODS: One hundred and thirty seven inpatients of a public psychiatric hospital and 180 controls were examined for the presence of IgG and IgM antibodies against T. gondii by enzyme-linked immunoassay (Diagnostic Automation Inc., Calabasas, CA, USA). The control population consisted of blood donors of a public blood bank and elderly persons attending a senior center in the same city. Age in controls (42 years +/- 20.2) was comparable with that of the psychiatric patients (43.7 years +/-13.8) (p = 0.42). Socio-demographic, clinical and behavioral characteristics from the patients were also obtained. RESULTS: Anti-T. gondii IgG antibodies indicating latent infection with T. gondii was found in 25 (18.2%) of 137 psychiatric inpatients and 16 (8.9%) of 180 controls (p = 0.02). Ten (26.3%) of 38 schizophrenic patients had latent infection and this prevalence was also significantly higher than that observed in controls (p = 0.005). Prevalence of anti-T. gondii IgM antibodies was comparable among patients and controls (4.4% vs 2.2%, respectively, p = 0.22). Multivariate analysis showed that T. gondii infection in inpatients was positively associated with sexual promiscuity (adjusted OR = 15.8; 95% CI: 3.8–64.8), unwashed raw fruit consumption (adjusted OR = 5.19; 95% CI: 2.3–11.3), and a history of surgery (adjusted OR = 6.5; 95% CI: 2.6–16), and negatively associated with lamb meat consumption (adjusted OR = 0.26; 95% CI: 0.10–0.63). CONCLUSION: In the present study, psychiatric inpatients in Durango, Mexico, in general and schizophrenia inpatients in particular had a significantly higher prevalence of T. gondii infection than the control group. Results suggest that unwashed raw fruit consumption might be the most important route of T. gondii transmission in our psychiatric inpatients while lamb meat consumption the less important. Additional studies will have to elucidate the causative relation between infection with T. gondii and psychiatric disorders

    Experimental Demonstration of a Magnetically Induced Warping Transition in a Topological Insulator Mediated by Rare-Earth Surface Dopants [Dataset]

    Get PDF
    20 pages. -- I. Growth methods. -- II. Er deposition and X-ray photoemission spectroscopy (XPS) coverage calibration. -- III. Er/Bi2Se2Te extended ARPES and XPS data. -- IV. Dy/Bi2Se2Te extended ARPES and XPS data. -- V. Theoretical model. -- VI. Theoretical prove of the Fermi velocity anisotropy upon Er doping. -- VII. MDCs and EDCs fittings: band dispersion and gap opening. -- VIII. Structural characterization: LEED patters.Magnetic topological insulators constitute a novel class of materials whose topological surface states (TSSs) coexist with long-range ferromagnetic order, eventually breaking time-reversal symmetry. The subsequent bandgap opening is predicted to co-occur with a distortion of the TSS warped shape from hexagonal to trigonal. We demonstrate such a transition by means of angle-resolved photoemission spectroscopy on the magnetically rare-earth (Er and Dy) surface-doped topological insulator Bi2Se2Te. Signatures of the gap opening are also observed. Moreover, increasing the dopant coverage results in a tunable p-type doping of the TSS, thereby allowing for a gradual tuning of the Fermi level toward the magnetically induced bandgap. A theoretical model where a magnetic Zeeman out-of-plane term is introduced in the Hamiltonian governing the TSS rationalizes these experimental results. Our findings offer new strategies to control magnetic interactions with TSSs and open up viable routes for the realization of the quantum anomalous Hall effect.Peer reviewe

    The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the extended Baryon Oscillation Spectroscopic Survey and from the second phase of the Apache Point Observatory Galactic Evolution Experiment

    Get PDF
    The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in operation since July 2014. This paper describes the second data release from this phase, and the fourteenth from SDSS overall (making this, Data Release Fourteen or DR14). This release makes public data taken by SDSS-IV in its first two years of operation (July 2014-2016). Like all previous SDSS releases, DR14 is cumulative, including the most recent reductions and calibrations of all data taken by SDSS since the first phase began operations in 2000. New in DR14 is the first public release of data from the extended Baryon Oscillation Spectroscopic Survey (eBOSS); the first data from the second phase of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2), including stellar parameter estimates from an innovative data driven machine learning algorithm known as "The Cannon"; and almost twice as many data cubes from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous release (N = 2812 in total). This paper describes the location and format of the publicly available data from SDSS-IV surveys. We provide references to the important technical papers describing how these data have been taken (both targeting and observation details) and processed for scientific use. The SDSS website (www.sdss.org) has been updated for this release, and provides links to data downloads, as well as tutorials and examples of data use. SDSS-IV is planning to continue to collect astronomical data until 2020, and will be followed by SDSS-V.Comment: SDSS-IV collaboration alphabetical author data release paper. DR14 happened on 31st July 2017. 19 pages, 5 figures. Accepted by ApJS on 28th Nov 2017 (this is the "post-print" and "post-proofs" version; minor corrections only from v1, and most of errors found in proofs corrected

    Generations No.7: Annual rendezvous with culture

    Get PDF
    Nuestra Institución se mueve articulada en tres ejes misionales: docencia, investigación y extensión; es precisamente en esta última, como parte de la labor de extensión cultural de la Universidad, que anualmente efectuamos la Feria del Libro de Bucaramanga, Ulibro. Cito al periodista mexicano Sergio González Rodríguez: “Tenemos que reaprender que la literatura no es solo entretener, tiene que servir para pensar, para analizar”, y a eso le apuesta la UNAB desde hace 12 años con Ulibro: una excusa para promover la cultura y el hábito de la lectura.Editorial; Por Alberto Montoya Puyana…3 Ulibro; Por Laura Camila Romero Martínez…4 La voz del graduado…6 Recomendaciones para elaborar una hoja de vida; Por Ana Carolina Torres P.…8 ABC de los posgrados; Por Carolina Toscano V....10 Comunicación y Artes Mensaje integral; Por Claudia Santamaría Valbuena…16 La conversación como salud; Por Carlos Germán Celis E....18 Ciudades inteligentes; Por Clara Inés Peña de Carrillo…20 Educación farmacéutica; Por Yaneth Rocío Orellana Hernández y Sergio Daniel Quiroga Flórez…22 La enseñanza del Derecho; Por Mario Guevara Mendoza…25 También comienza por casa; Por Hugo F. Prada A…28 Los macroproyectos Investigaciones UNAB; Por Miguel Ángel Hernández Rey…30 Graduados destacados; Por Redacción Generaciones UNAB…34 Generaciones en cifras; Por Redacción Generaciones UNAB…42 Centro de Apoyo y Formación Empresarial; Por Redacción Generaciones UNAB…43 6ª Feria del Empleo; Por Redacción Generaciones UNAB…46 Encuentros…48Our Institution moves articulated in three missionary axes: teaching, research and extension; It is precisely in the latter, as part of the cultural outreach work of the University, that we annually hold the Bucaramanga Book Fair, Ulibro. I quote the Mexican journalist Sergio González Rodríguez: “We have to relearn that literature is not only entertaining, it has to serve to think, to analyze”, and that is what the UNAB has been betting on for 12 years with Ulibro: an excuse to promote culture and the habit of reading

    Enfermedades crónicas

    Get PDF
    Adherencia al tratamiento farmacológico y relación con el control metabólico en pacientes con DM2Aluminio en pacientes con terapia de reemplazo renal crónico con hemodiálisis en Bogotá, ColombiaAmputación de extremidades inferiores: ¿están aumentando las tasas?Consumo de edulcorantes artificiales en jóvenes universitariosCómo crecen niños normales de 2 años que son sobrepeso a los 7 añosDiagnóstico con enfoque territorial de salud cardiovascular en la Región MetropolitanaEfecto a corto plazo de una intervención con ejercicio físico, en niños con sobrepesoEfectos de la cirugía bariátrica en pacientes con síndrome metabólico e IMC < 35 KG/M2Encuesta mundial de tabaquismo en estudiantes de profesiones de saludEnfermedades crónicas no transmisibles: Consecuencias sociales-sanitarias de comunidades rurales en ChileEpidemiología de las muertes hospitalarias por patologías relacionadas a muerte encefálica, Chile 2003-2007Estado nutricional y conductas alimentarias en adolescentes de 4º medio de la Región de CoquimboEstudio de calidad de vida en una muestra del plan piloto para hepatitis CEvaluación del proceso asistencial y de resultados de salud del GES de diabetes mellitus 2Factores de riesgo cardiovascular en población universitaria de la Facsal, universidad de TarapacáImplicancias psicosociales en la génesis, evolución y tratamiento de pacientes con hipertensión arterial esencialInfarto agudo al miocardio (IAM): Realidad en el Hospital de Puerto Natales, 2009-2010Introducción de nuevas TIC y mejoría de la asistencia a un programa de saludNiños obesos atendidos en el Cesfam de Puerto Natales y su entorno familiarPerfil de la mortalidad por cáncer de cuello uterino en Río de JaneiroPerfil del paciente primo-consultante del Programa de Salud Cardiovascular, Consultorio Cordillera Andina, Los AndesPrevalencia de automedicación en mujeres beneficiarias del Hospital Comunitario de Til-TiPrevalencia de caries en población preescolar y su relación con malnutrición por excesoPrevalencia de retinopatía diabética en comunas dependientes del Servicio de Salud Metropolitano Occidente (SSMOC)Problemas de adherencia farmacológica antihipertensiva en población mapuche: Un estudio cualitativoRol biológico de los antioxidantes innatos en pacientes portadores de VIH/SidaSobrepeso en empleados de un restaurante de una universidad pública del estado de São Paul

    The 13th Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the SDSS-IV Survey Mapping Nearby Galaxies at Apache Point Observatory

    Get PDF
    The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) began observations in July 2014. It pursues three core programs: APOGEE-2,MaNGA, and eBOSS. In addition, eBOSS contains two major subprograms: TDSS and SPIDERS. This paper describes the first data release from SDSS-IV, Data Release 13 (DR13), which contains new data, reanalysis of existing data sets and, like all SDSS data releases, is inclusive of previously released data. DR13 makes publicly available 1390 spatially resolved integral field unit observations of nearby galaxies from MaNGA,the first data released from this survey. It includes new observations from eBOSS, completing SEQUELS. In addition to targeting galaxies and quasars, SEQUELS also targeted variability-selected objects from TDSS and X-ray selected objects from SPIDERS. DR13 includes new reductions ofthe SDSS-III BOSS data, improving the spectrophotometric calibration and redshift classification. DR13 releases new reductions of the APOGEE-1data from SDSS-III, with abundances of elements not previously included and improved stellar parameters for dwarf stars and cooler stars. For the SDSS imaging data, DR13 provides new, more robust and precise photometric calibrations. Several value-added catalogs are being released in tandem with DR13, in particular target catalogs relevant for eBOSS, TDSS, and SPIDERS, and an updated red-clump catalog for APOGEE.This paper describes the location and format of the data now publicly available, as well as providing references to the important technical papers that describe the targeting, observing, and data reduction. The SDSS website, http://www.sdss.org, provides links to the data, tutorials and examples of data access, and extensive documentation of the reduction and analysis procedures. DR13 is the first of a scheduled set that will contain new data and analyses from the planned ~6-year operations of SDSS-IV.PostprintPeer reviewe
    corecore