5,162 research outputs found

    Scaling-up climate services with users in Latin America

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    Latin America farmers are highly vulnerable to climate variability, with crop losses observed throughout the region on a virtually annual basis. For instance, as indicated by the United Nations’ Food and Agriculture Organization (FAO) and World Food Program (WFP), the 2014–2017 drought conditions in Central America affected over 3.5 million people in Guatemala, Honduras and El Salvador. At the same time, local stakeholders and farmers generally have limited access to existing climate and forecast information, do not have sufficient capacities to understand the climate information and/or mechanisms to relate this information to the impact that climate variations can generate at a local level. This precludes the translation of information into actionable knowledge, and therefore into action. In this study, we describe a process through which scientists and strategic partners have co-developed, tested and scaled out an approach to assess, co-produce, translate and transfer climate information to enable agricultural decision making –the Local Technical Agroclimatic Committees (LTAC). LTACs allow open and clear dialogues about climate variations at multiple timescales, how these can affect crops, and the design of measures to reduce crop loss, particularly providing agronomic recommendations to farmers. We systematically describe the process of evidence generation, creation, partner engagement, scaling up, and monitoring of the approach throughout Latin America. Currently, 35 LTACs exist in 9 Latin American countries, engaging more than 250 public and private institutions, increasing the resilience and food security of an estimated 330,000 farmers, and potentially transforming how Latin American farmers manage climate risk. The study illustrates changes in institutional and farmers' capacities to co-produce, translate and use climate information and explores how better climate and crop prediction models can effectively underpin this process. We show how strategic alliances with farmer organizations, national public, and private and regional climate outlook forums help deliver improved and accurate climate information to users. Finally, we document how LTACs and their integration with other local-scale processes have led to changes in farmers’ management practices to take better advantage of good climatic conditions or avoid losses

    Cosecha de Alcances: Valoración de las transformaciones producidas por las Mesas Técnicas Agroclimáticas (MTA) en Latinoamérica

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    Durante el 2019 se realizó un proceso de análisis de las transformaciones que han generado las Mesas Técnicas Agroclimáticas (MTA), en los territorios en que han sido establecidas durante los últimos 6 años. El estudio se enfoca en los cambios observables de comunidades, organizaciones o instituciones que han modificado sus acciones, relaciones, políticas y prácticas en cuatro países de Latinoamérica. Cinco áreas de transformación han sido identificadas i) mayor confianza en la calidad de información climática y agroclimática en el nivel local; ii) información agroclimática más conocida, comprensible y conectada; iii) democratización de conocimiento climático; iv) transformaciones en las prácticas agrícolas, y v) incidencia política y transformación institucional. Se verifican más de 140 alcances o cambios sobre dichas áreas. Se evidencia que las MTA analizadas han promovido un mayor acercamiento de las Instituciones Meteorológicas Nacionales a las necesidades de los territorios, lo que, a su vez, ha propiciado la creación de comunidades de práctica locales sobre la aplicación de conocimientos de clima en la toma de decisiones. En efecto, se tiene evidencia que los agricultores adaptan sus prácticas productivas tomando decisiones basadas en información de variabilidad climática local, reduciendo pérdidas y aumentando rentabilidad. Se demuestra, además, que el desarrollo de alianzas inter-institucionales derivadas de las MTA en los países, ayudan a la construcción y fortalecimiento de políticas públicas locales y nacionales para la adaptación al cambio y la variabilidad climática en la agricultura. Finalmente, se identifican diversas oportunidades y desafíos relacionados con liderazgo y la sostenibilidad del proceso de establecimiento de las MTA en Latinoamérica.During 2019 a process of analysis of the effects or transformations that the Local Agro climatic Technical Committees (MTA) have been carried out, in the territories in which they have been established during the last 5 years. The study focuses on the observable changes of individuals, communities, organizations or institutions that have modified their actions, relationships, policies and practices in five Latin American countries. Five areas of transformation have been identified as outcomes of the MTAs, among which are analyzed: i) greater confidence in the quality of climate and agro climatic information at the local level; ii) best-known, understandable and connected agro climatic information; iii) democratization of climate knowledge; iv) transformations in agricultural practices, and v) political influence and institutional transformation. More than 140 scopes or changes over these areas are verified. There is evidence that the MTAs have promoted a closer approach of the national meteorological institutions to the need of the territories farmers, which in turn has led to the creation of local communities of practice on the application of climate knowledge in decision making agricultural. Indeed, evidence shows that farmers adapt their productive practices by making decisions based on information on local climate variability, reducing losses and increasing profitability. It is also demonstrated that the development of inter-institutional alliances derived from MTAs in the countries, helps to build and strengthen local and national public policies for adaptation to climate change and variability in agriculture. Finally, various opportunities and challenges related to leadership and the sustainability of the MTA establishment process in Latin America are identified

    A Re-evaluation of Electron-Transfer Mechanisms in Microbial Electrochemistry: Shewanella Releases Iron that Mediates Extracellular Electron Transfer

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    Exoelectrogenic bacteria can couple their metabolism to extracellular electron acceptors, including macroscopic electrodes, and this has applications in energy production, bioremediation and biosensing. Optimisation of these technologies relies on a detailed molecular understanding of extracellular electron-transfer (EET) mechanisms, and Shewanella oneidensis MR-1 (MR-1) has become a model organism for such fundamental studies. Here, cyclic voltammetry was used to determine the relationship between the surface chemistry of electrodes (modified gold, ITO and carbon electrodes) and the EET mechanism. On ultra-smooth gold electrodes modified with self-assembled monolayers containing carboxylic-acid-terminated thiols, an EET pathway dominates with an oxidative catalytic onset at 0.1V versus SHE. Addition of iron(II)chloride enhances the catalytic current, whereas the siderophore deferoxamine abolishes this signal, leading us to conclude that this pathway proceeds via an iron mediated electron transfer mechanism. The same EET pathway is observed at other electrodes, but the onset potential is dependent on the electrolyte composition and electrode surface chemistry. EET pathways with onset potentials above -0.1V versus SHE have previously been ascribed to direct electron-transfer (DET) mechanisms through the surface exposed decaheme cytochromes (MtrC/OmcA) of MR-1. In light of the results reported here, we propose that the previously identified DET mechanism of MR-1 needs to be re-evaluated

    Social presence and dishonesty in retail

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    Self-service checkouts (SCOs) in retail can benefit consumers and retailers, providing control and autonomy to shoppers independent from staff, together with reduced queuing times. Recent research indicates that the absence of staff may provide the opportunity for consumers to behave dishonestly, consistent with a perceived lack of social presence. This study examined whether a social presence in the form of various instantiations of embodied, visual, humanlike SCO interface agents had an effect on opportunistic behaviour. Using a simulated SCO scenario, participants experienced various dilemmas in which they could financially benefit themselves undeservedly. We hypothesised that a humanlike social presence integrated within the checkout screen would receive more attention and result in fewer instances of dishonesty compared to a less humanlike agent. This was partially supported by the results. The findings contribute to the theoretical framework in social presence research. We concluded that companies adopting self-service technology may consider the implementation of social presence in technology applications to support ethical consumer behaviour, but that more research is required to explore the mixed findings in the current study.<br/

    Environmental impact of early palaeometallurgy: pollen and geochemical analysis

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    International audienceInterdisciplinary research was carried out in mid-level mountain areas in France with the aim of documenting historical mining and smelting activities by means of pollen and geochemical analyses. These investigations were made on cores collected in French peatlands in the Morvan (northern Massif Central), at Mont Lozère (southern Massif Central) and in the Basque Country (Pyrénées). Different periods of mining were recognised from Prehistory to modern times through the presence of anthropogenic lead in peat. Some of these were already known from archaeological dates or historical archives, especially for mediaeval and modern periods. However prehistoric ancient mining activities, as early as the Middle Bronze Age (ca. 1700 b.c.), were also discovered. They had all led to modifications in plant cover, probably related in part to forest clearance necessary to supply energy for mining and smelting

    Carnegie Supernova Project: Kinky i-band light curves of Type Ia supernovae

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    We present detailed investigation of a specific i-band light-curve feature in Type Ia supernovae (SNe Ia) using the rapid cadence and high signal-to-noise ratio light curves obtained by the Carnegie Supernova Project. The feature is present in most SNe Ia and emerges a few days after the i-band maximum. It is an abrupt change in curvature in the light curve over a few days and appears as a flattening in mild cases and a strong downward concave shape, or a 'kink', in the most extreme cases. We computed the second derivatives of Gaussian Process interpolations to study 54 rapid-cadence light curves. From the second derivatives we measure: (1) the timing of the feature in days relative to i-band maximum; tdm2(i) and (2) the strength and direction of the concavity in mag d-2; dm2(i). 76 per cent of the SNe Ia show a negative dm2(i), representing a downward concavity - either a mild flattening or a strong 'kink'. The tdm2(i) parameter is shown to correlate with the colour-stretch parameter sBV, a SN Ia primary parameter. The dm2(i) parameter shows no correlation with sBV and therefore provides independent information. It is also largely independent of the spectroscopic and environmental properties. Dividing the sample based on the strength of the light-curve feature as measured by dm2(i), SNe Ia with strong features have a Hubble diagram dispersion of 0.107 mag, 0.075 mag smaller than the group with weak features. Although larger samples should be obtained to test this result, it potentially offers a new method for improving SN Ia distance determinations without shifting to more costly near-infrared or spectroscopic observations.Fil: Pessi, Priscila Jael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Hsiao, E. Y.. Florida State University; Estados UnidosFil: Folatelli, Gaston. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Anderson, J. P.. European Southern Observatory Santiago; ChileFil: Burns, C. R.. No especifíca;Fil: Uddin, S.. Texas A&M University; Estados UnidosFil: Galbany, L.. Consejo Superior de Investigaciones Científicas; EspañaFil: Phillips, M. M.. No especifíca;Fil: Morrell, N.. No especifíca;Fil: Ashall, C.. University of Hawaii at Manoa; Estados UnidosFil: Baron, E.. No especifíca;Fil: Contreras, C.. No especifíca;Fil: Hamuy, M.. Texas A&M University; Estados UnidosFil: Hoeflich, P.. Florida State University; Estados UnidosFil: Krisciunas, K.. Texas A&M University; Estados UnidosFil: Kumar, S.. Florida State University; Estados UnidosFil: Lu, J.. Florida State University; Estados UnidosFil: Martinez, Laureano. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Piro, A. L.. No especifíca;Fil: Shahbandeh, M.. Florida State University; Estados UnidosFil: Stritzinger, M. D.. University Aarhus; DinamarcaFil: Suntzeff, N. B.. Texas A&M University; Estados Unido

    Aldo Keto Reductase 1B7 and Prostaglandin F2α Are Regulators of Adrenal Endocrine Functions

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    Prostaglandin F2α (PGF2α), represses ovarian steroidogenesis and initiates parturition in mammals but its impact on adrenal gland is unknown. Prostaglandins biosynthesis depends on the sequential action of upstream cyclooxygenases (COX) and terminal synthases but no PGF2α synthases (PGFS) were functionally identified in mammalian cells. In vitro, the most efficient mammalian PGFS belong to aldo-keto reductase 1B (AKR1B) family. The adrenal gland is a major site of AKR1B expression in both human (AKR1B1) and mouse (AKR1B3, AKR1B7). Thus, we examined the PGF2α biosynthetic pathway and its functional impact on both cortical and medullary zones. Both compartments produced PGF2α but expressed different biosynthetic isozymes. In chromaffin cells, PGF2α secretion appeared constitutive and correlated to continuous expression of COX1 and AKR1B3. In steroidogenic cells, PGF2α secretion was stimulated by adrenocorticotropic hormone (ACTH) and correlated to ACTH-responsiveness of both COX2 and AKR1B7/B1. The pivotal role of AKR1B7 in ACTH-induced PGF2α release and functional coupling with COX2 was demonstrated using over- and down-expression in cell lines. PGF2α receptor was only detected in chromaffin cells, making medulla the primary target of PGF2α action. By comparing PGF2α-responsiveness of isolated cells and whole adrenal cultures, we demonstrated that PGF2α repressed glucocorticoid secretion by an indirect mechanism involving a decrease in catecholamine release which in turn decreased adrenal steroidogenesis. PGF2α may be regarded as a negative autocrine/paracrine regulator within a novel intra-adrenal feedback loop. The coordinated cell-specific regulation of COX2 and AKR1B7 ensures the generation of this stress-induced corticostatic signal

    Detrimental hemodynamic and inflammatory effects of microparticles originating from septic rats

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    Objective: Microparticles (MPs) are membrane vesicles with procoagulant and proinflammatory properties released during cell activation and might be potentially involved in the pathophysiology of septic shock. This study was designed to assess the effects of MPs from septic origin on the systemic hemodynamics as well as on the inflammatory, oxidative, and nitrosative stresses.Design: A prospective, randomized, controlled experimental study with repeated measurements. Setting: Investigational animal laboratory. Subjects: Forty healthy rats were randomly allocated to three groups: 10 animals inoculated with MPs isolated from control rats (cMPs), 15 animals inoculated with MPs isolated from sham rats (shMPs), and 15 animals inoculated with MPs isolated from rats with peritonitis (sMPs). Interventions: Rats were anesthetized, mechanically ventilated, and infused with the same amount of cMPs, shMPs, or sMPs. We measured the heart rate, mean arterial pressure, carotid artery, and portal vein blood flows. Hemodynamic parameters were recorded during 7 hours, and then animals were killed. Aorta and heart were harvested for further in vitro tissue analyses. Measurements and Main Results: 1) The cellular origin (phenotype) but not the circulating concentration of MPs was different in septic rats, characterized by a significant increase in leukocyte-derived MPs. 2) sMPs but not cMPs or shMPs decreased mean arterial pressure without any effect on carotid artery and portal vein blood flows. 3) Rats inoculated with sMPs exhibited an increase in superoxide ion production and nuclear factor kappa B activity, overexpression of inducible nitric oxide synthase with subsequent nitric oxide overproduction and decrease in endothelial nitric oxide synthase activation. Conclusions: Rats with sepsis induced by peritonitis exhibited a specific phenotype of MPs. Inoculation of sMPs in healthy rats reproduced hemodynamic, septic inflammatory patterns, associated with oxidative and nitrosative stresses
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