242 research outputs found

    Carbon input threshold for soil carbon budget optimization in eroding vineyards

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    Previous studies have documented that, relative to conventional tillage (CT), alternative soil management (reduced tillage, mulching, or cover crops) decreases soil erosion and increases soil organic matter (SOM) in vineyards. These previous studies, however, failed to consider the loss of soil organic carbon (SOC) with erosion that could occur with the adoption of agro-environmental measures (AEM) in a semiarid environment. Accordingly, the aims of this study were to determine whether changes in SOC content under AEM management are always positive and to develop a conceptual model for estimating the "SOC threshold". The SOC threshold was defined as that level of SOC in an AEM-managed vineyard above which erosion will result in greater loss of C than occur in a comparable vineyard with CT management. SOC was analyzed at a 100 paired sites (vineyards with AEM management vs. CT). The results showed that in some cases the loss of C was higher with AEM than with CT. Overall, the results indicate that the SOC threshold may be a key parameter in determining the best AEM measures for vineyards that are on slopes and therefore vulnerable to erosion

    Use of barley straw residues to avoid high erosion and runoff rates on persimmon plantations in Eastern Spain under low frequency-high magnitude simulated rainfall events

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    [EN] Soil and water losses due to agricultural mismanagement are high and non-sustainable in many orchards. An experiment was set up with rainfall simulation at 78 mm h(-1) over 1 hour on 20 paired plots of 2 m(2) (bare and straw covered) in new persimmon plantations in Eastern Spain. Effects of straw cover on the control of soil and water losses were assessed. An addition of 60% straw cover (75 gm(-2)) resulted in delayed ponding and runoff generation and consequently reduced water losses from 60% to 13% of total rainfall. The straw cover reduced raindrop impact and thus sediment detachment from 1014 to 47 g plot(-1) h(-1). The erosion rate was reduced from 5.1 to 0.2 Mg ha-(1) h(-1). The straw mulch was found to be extremely efficient in reducing soil erosion rates.The research projects GL2008-02879/BTE, LEDDRA 243857 and RECARE-FP7 (no. 603498, http://recare-project.eu/) supported this research.Cerdà, A.; González-Pelayo, Ó.; Giménez Morera, A.; Jordán, A.; Pereira, P.; Novara, A.; Brevik, EC.... (2016). Use of barley straw residues to avoid high erosion and runoff rates on persimmon plantations in Eastern Spain under low frequency-high magnitude simulated rainfall events. Soil Research. 54(2):154-165. https://doi.org/10.1071/SR15092S15416554

    Convención Internacional sobre la eliminación de todas las formas de discriminación racial. Comité para la eliminación de la discriminación racial

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    Convención Internacional sobre la eliminación de todas las formas de discriminación racial. Comité para la eliminación de la discriminación racial.EXAMEN DE LOS INFORMES PRESENTADOS POR LOS ESTADOS PARTES DE CONFORMIDAD CON EL ARTÍCUlo 9 DE LA CONVENCiÓNDecimoquinto informe periódico que los Estados Partes debían presentar en 1998AdiciónUruguay(13 de julio de 1998

    Genomic resources for flatfish research and their applications

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    Flatfishes are a group of teleosts of high commercial and environmental interest, whose biology is still poorly understood. The recent rapid development of different 'omic' technologies is, however, enhancing the knowledge of the complex genetic control underlying different physiological processes of flatfishes. This review describes the different functional genomic approaches and resources currently available for flatfish research and summarizes different areas where microarray-based gene expression analysis has been applied. The increase in genome sequencing data has also allowed the construction of genetic linkage maps in different flatfish species; these maps are invaluable for investigating genome organization and identifying genetic traits of commercial interest. Despite the significant progress in this field, the genomic resources currently available for flatfish are still scarce. Further intensive research should be carried out to develop larger genomic sequence databases, high-density microarrays and, more detailed, complete linkage maps, using second-generation sequencing platforms. These tools will be crucial for further expanding the knowledge of flatfish physiology, and it is predicted that they will have important implications for wild fish population management, improved fish welfare and increased productivity in aquaculture.Peer reviewed: YesNRC publication: Ye

    Multi-messenger observations of a binary neutron star merger

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    On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

    Utilización de un sistema de inyección en flujo multijeringa para la extracción en fase sólida de plaguicidas organofosforados de muestras de agua y su determinación por CG/EM

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    En el presente trabajo se desarrolló un método selectivo y reproducible para evaluar plaguicidas organofosforados (POFs) en aguas de consumo humano por cromatografía de gases (CG) con detección por espectrometría de masa (EM). La extracción en fase sólida de los POFs en disco, se realizó en un sistema de inyección en flujo multijeringa (MSFIA) que permitió la automatización del procedimiento analítico con un importante ahorro de disolventes y tiempo, una reducción en la generación de residuos y del coste por análisis. La validación del método indicó linealidad entre 0,075-5,0 µg/L con límites de detección de 0,01 µg/L para Diazinon y Clorpirifos y de 0,05 µg/L para Malation y Metil paration respectivamente. La recuperación para todos los casos estuvo comprendida entre 91,7 y 102,8% con un C.V. £ 3,6%. El método propuesto se utilizó para analizar aguas de grifo y agua de grifo enriquecidas con los plaguicidas en el intervalo de concentración entre 0,15 y 5,0 µg/L con una frecuencia de análisis de 10 muestras/hora

    Los métodos cinéticos. Una alternativa atractiva para el análisis espectrofotométrico de nitritos en aguas a niveles de traza y ultratraza

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    Los métodos catalítico cinéticos representan una de las alternativas más atractivas para la determinación espectrofotométrica de nitritos a niveles traza y ultratraza. En los últimos años han aparecido en la literatura una serie de métodos espectrofotométricos para la determinación de nitritos en aguas, que se basan en el efecto catalítico cinético de este ión en la oxidación de diversas moléculas orgánicas, por parte del ión bromato en medio ácido. Estos procedimientos son simples y requieren de una instrumentación sencilla y accesible a muchos laboratorios. El principal objetivo del presente trabajo es hacer una revisión comparativa y crítica de los diversos desarrollos metodológicos propuestos, así como proponer algunas alternativas metodológicas que aún no han sido exploradas

    Search for gravitational waves associated with fast radio bursts detected by CHIME/FRB during the LIGO-Virgo observing Run O3a

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    We search for gravitational-wave (GW) transients associated with fast radio bursts (FRBs) detected by the Canadian Hydrogen Intensity Mapping Experiment Fast Radio Burst Project, during the first part of the third observing run of Advanced LIGO and Advanced Virgo (2019 April 1 15:00 UTC–2019 October 1 15:00 UTC). Triggers from 22 FRBs were analyzed with a search that targets both binary neutron star (BNS) and neutron star–black hole (NSBH) mergers. A targeted search for generic GW transients was conducted on 40 FRBs. We find no significant evidence for a GW association in either search. Given the large uncertainties in the distances of our FRB sample, we are unable to exclude the possibility of a GW association. Assessing the volumetric event rates of both FRB and binary mergers, an association is limited to 15% of the FRB population for BNS mergers or 1% for NSBH mergers. We report 90% confidence lower bounds on the distance to each FRB for a range of GW progenitor models and set upper limits on the energy emitted through GWs for a range of emission scenarios. We find values of order 1051–1057 erg for models with central GW frequencies in the range 70–3560 Hz. At the sensitivity of this search, we find these limits to be above the predicted GW emissions for the models considered. We also find no significant coincident detection of GWs with the repeater, FRB 20200120E, which is the closest known extragalactic FRB

    Advanced Virgo Plus. Future perspectives

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    While completing the commissioning phase to prepare the Virgo interferometer for the next joint Observation Run (O4), the Virgo collaboration is also finalizing the design of the next upgrades to the detector to be employed in the following Observation Run (O5). The major upgrade will concern decreasing the thermal noise limit, which will imply using very large test masses and increased laser beam size. But this will not be the only upgrade to be implemented in the break between the O4 and O5 observation runs to increase the Virgo detector strain sensitivity. The paper will cover the challenges linked to this upgrade and implications on the detector’s reach and observational potential, reflecting the talk given at 12th Cosmic Ray International Seminar - CRIS 2022 held in September 2022 in Napoli
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