220 research outputs found

    Características fisiológicas de plantas hibernais com potencial fitorremediador sob influência dos herbicidas fomesafen e sulfentrazone.

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    The use of plant species for phytoremediation of soil contaminated with persistent herbicides, such as inhibitors of the protoporphyrinogen oxidase enzyme (PROTOX), is an interesting alternative from the economic and environmental point of view. This work aimed to evaluate the influence of fomesafen and sulfentrazone on the characteristics related to the physiology of winter species with potential for phytoremediation of soil contaminated by these herbicides. Two experiments were installed in a greenhouse, one with the herbicide fomesafen and another with the sulfentrazone, in a randomized complete block design with four replications. Fomesafen (0.0, 0.125, 0.250, and 0.5 kg ha-1) and sulfentrazone (0.0, 0.3, 0.6, and 1.2 kg ha-1), commercial brands Flex® and Boral 500®, respectively, were applied pre-emergence on species with phytoremediation potential (black oats, vetch, turnip and lotus). The chlorophyll index, the carboxylation efficiency (EC - mol CO2 m-2 s-1), the stomatal conductance of water vapors (Gs - mol m-1 s-1), the internal CO2 concentration (Ci - μmol mol-1), the transpiration rate (E - mol H2O m-2 s-1), the amount of CO2 consumed (QT - μmol mol-1) and the water use efficiency (UEA - mol CO2 mol H2O-1), the leaf temperature ΔT (ºC), the photosynthetic rate (A - μmol m-2 s-1) and the shoot dry mass (g vase-1) were evaluated 45 days after plant emergence. It was observed that the vetch presented the best results for all evaluated variables, thus demonstrating potential to be further tested for phytoremediation of soils contaminated with the herbicides fomesafen and sulfentrazone.O emprego de espécies vegetais para fitorremediação de solos contaminados com herbicidas persistentes, como os inibidores da enzima protoporfirinogênio oxidase (PROTOX), é uma alternativa interessante dos pontos de vista econômico e ambiental. O objetivo deste trabalho foi avaliar a influência de fomesafen e sulfentrazone nas características relacionadas à fisiologia de espécies hibernais com potencial para aplicação como fitorremediadoras de solo contaminado por esses herbicidas. Dois experimentos foram instalados em casa de vegetação, um com o herbicida fomesafen e outro com o sulfentrazone, no delineamento de blocos casualizados com quatro repetições. Foram testadas doses dos herbicidas fomesafen (0,0; 0,125; 0,250; e 0,5 kg ha-1) e sulfentrazone (0,0; 0,3; 0,6; e 1,2 kg ha-1), marcas comerciais Flex® e Boral 500®, respectivamente, aplicadas na pré-emergência das espécies com potencial fitorremediador (aveia-preta, ervilhaca, nabo e cornichão). Aos 45 dias após a emergência das plantas, foram avaliados o índice de clorofila, a eficiência de carboxilação (EC- mol CO2 m-2 s-1), a condutância estomática de vapores de água (Gs - mol m-1 s-1), a concentração interna de CO2 (Ci - µmol mol-1), a taxa de transpiração (E - mol H2O m-2 s-1), a quantidade de CO2 consumido (QT - µmol mol-1), o uso eficiente da água (UEA - mol CO2 mol H2O-1), a temperatura da folha ΔT (ºC), a taxa fotossintética (A - µmol m-2 s-1) e a massa seca (g vaso-1) da parte aérea. Observou-se que a ervilhaca apresenta os melhores resultados para todas as variáveis avaliadas, demonstrando assim potencial para ser testada como fitorremediadora de solos contaminados com os herbicidas fomesafen e sulfentrazone

    Empirical agent-based modelling of everyday pro-environmental behaviours at work

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    We report on agent-based modelling work in the LOCAW project (Low Carbon at Work: Modelling Agents and Organisations to Achieve Transition to a Low Carbon Europe). The project explored the effectiveness of various backcasting scenarios conducted with case study organisations in bringing about pro-environmental change in the workforce in the domains of transport, energy use and waste. The model used qualitative representations of workspaces in formalising each scenario, and decision trees learned from questionnaire responses to represent decision-making. We describe the process by which the decision trees were constructed, noting that the use of decision trees in agent-based models requires particular considerations owing to the potential use of explanatory variables in model dynamics. The results of the modelling in various scenarios emphasise the importance of structural environmental changes in facilitating everyday pro-environmental behaviour, but also show there is a role for psychological variables such as norms, values and efficacy. As such, the topology of social interactions is a potentially important driver, raising the interesting prospect that both workplace geography and organisational hierarchy have a role to play in influencing workplace pro-environmental behaviours

    The Large Enriched Germanium Experiment for Neutrinoless Double Beta Decay (LEGEND)

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    The observation of neutrinoless double-beta decay (0νββ{\nu}{\beta}{\beta}) would show that lepton number is violated, reveal that neutrinos are Majorana particles, and provide information on neutrino mass. A discovery-capable experiment covering the inverted ordering region, with effective Majorana neutrino masses of 15 - 50 meV, will require a tonne-scale experiment with excellent energy resolution and extremely low backgrounds, at the level of ∼\sim0.1 count /(FWHM⋅\cdott⋅\cdotyr) in the region of the signal. The current generation 76^{76}Ge experiments GERDA and the MAJORANA DEMONSTRATOR utilizing high purity Germanium detectors with an intrinsic energy resolution of 0.12%, have achieved the lowest backgrounds by over an order of magnitude in the 0νββ{\nu}{\beta}{\beta} signal region of all 0νββ{\nu}{\beta}{\beta} experiments. Building on this success, the LEGEND collaboration has been formed to pursue a tonne-scale 76^{76}Ge experiment. The collaboration aims to develop a phased 0νββ{\nu}{\beta}{\beta} experimental program with discovery potential at a half-life approaching or at 102810^{28} years, using existing resources as appropriate to expedite physics results.Comment: Proceedings of the MEDEX'17 meeting (Prague, May 29 - June 2, 2017

    Cryogenic characterization of a LiAlO 2 crystal and new results on spin-dependent dark matter interactions with ordinary matter: CRESST Collaboration

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    In this work, a first cryogenic characterization of a scintillating LiAlO 2 single crystal is presented. The results achieved show that this material holds great potential as a target for direct dark matter search experiments. Three different detector modules obtained from one crystal grown at the Leibniz-Institut für Kristallzüchtung (IKZ) have been tested to study different properties at cryogenic temperatures. Firstly, two 2.8 g twin crystals were used to build different detector modules which were operated in an above-ground laboratory at the Max Planck Institute for Physics (MPP) in Munich, Germany. The first detector module was used to study the scintillation properties of LiAlO 2 at cryogenic temperatures. The second achieved an energy threshold of (213.02 ± 1.48) eV which allows setting a competitive limit on the spin-dependent dark matter particle-proton scattering cross section for dark matter particle masses between 350MeV/c2 and 1.50GeV/c2. Secondly, a detector module with a 373 g LiAlO 2 crystal as the main absorber was tested in an underground facility at the Laboratori Nazionali del Gran Sasso (LNGS): from this measurement it was possible to determine the radiopurity of the crystal and study the feasibility of using this material as a neutron flux monitor for low-background experiments. © 2020, The Author(s)

    Searches for Light Dark Matter with the CRESST-III Experiment

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    Cryogenic Rare Event Search with Superconducting Thermometers (CRESST) is a long-standing direct dark matter detection experiment with cryogenic detectors located at the underground facility Laboratori Nazionali del Gran Sasso in Italy. CRESST-III, the third generation of CRESST, was specifically designed to have a world-leading sensitivity for low-mass dark matter (DM) (less than 2\ua0GeV/c 2) to probe the spin-independent DM-nucleus cross section. At present, a large part of the parameter space for spin-independent scattering off nuclei remains untested for dark matter particles with masses below few GeV/c 2 although many motivated theoretical models having been proposed. The CRESST-III experiment employs scintillating CaWO 4 crystals of ∼ 25\ua0g as target material for dark matter interactions operated as cryogenic scintillating calorimeters at\ua0∼ 10\ua0mK. CRESST-III first data taking was successfully completed in 2018, achieving an unprecedented energy threshold for nuclear recoils. This result extended the present sensitivity to DM particles as light as ∼ 160\ua0MeV/c 2. In this paper, an overview of the CRESST-III detectors and results will be presented

    Lithium-Containing Crystals for Light Dark Matter Search Experiments

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    In the current direct dark matter search landscape, the leading experiments in the sub-GeV mass region mostly rely on cryogenic techniques which employ crystalline targets. One attractive type of crystals for these experiments is those containing lithium, due to the fact that 7Li is an ideal candidate to study spin-dependent dark matter interactions in the low mass region. Furthermore, 6Li can absorb neutrons, a challenging background for dark matter experiments, through a distinctive signature which allows the monitoring of the neutron flux directly on site. In this work, we show the results obtained with three different detectors based on LiAlO 2, a target crystal never used before in cryogenic experiments

    New/emerging psychoactive substances and associated psychopathological consequences

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    Submitted 24 November 2018, Revised 18 June 2019, Accepted 26 June 2019, Published online 22 July 2019BackgroundThe present paper provides an updated review of both the large number of new/novel/emerging psychoactive substances (NPS) and their associated psychopathological consequences. Focus was here given on identification of those NPS being commented in specialised online sources and the related short-/long-term psychopathological and medical ill-health effects.MethodsNPS have been identified through an innovative crawling/navigating software, called the 'NPS.Finder®', created in order to facilitate the process of early recognition of NPS online. A range of information regarding NPS, including chemical and street names; chemical formula; three-dimensional image and anecdotally reported clinical/psychoactive effects, were here made available.ResultsUsing the 'NPS.Finder®' approach, a few thousand NPS were here preliminarily identified, a number which is about 4-fold higher than those figures suggested by European and international drug agencies. NPS most commonly associated with the onset of psychopathological consequences included here synthetic cannabinoids/cannabimimetics; new synthetic opioids; ketamine-like dissociatives; novel stimulants; novel psychedelics and several prescription and over-the-counter medicines.ConclusionsThe ever-increasing changes in terms of recreational psychotropics' availability represent a relatively new challenge for psychiatry, as the pharmacodynamics and pharmacokinetics of many NPS have not been thoroughly understood. Health/mental health professionals should be informed about the range of NPS; their intake modalities; their psychoactive sought-after effects; the idiosyncratic psychotropics' combinations and finally, their medical and psychopathological risks.Peer reviewe
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