34 research outputs found

    Depuration Capacity of Mussels (Mytilus galloprovincialis) in Presence of Marteilia Spp. Parasites

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    Bivalve molluscs are filter-feeding organisms present in the water column: during their activity, they could retain micro-organisms that are potentially dangerous to human health. For this reason, EU Regulations may require that a purification treatment be performed prior to bivalve trade. The length of the purification process could be affected by stress factors, such as parasitic infections. The purpose of this study was to determine if the presence of Marteilia spp. parasite in shellfish could modify time and efficacy of their microbiological purification treatment, in order to set up specific protocols. Lysosomal membrane stability, phagocytosis capacity, granulocyte/hyalinocyte rate and neutral lipid accumulation are biomarkers used to evaluate shellfish physiological state. These biomarkers were used to exclude any differences caused by stressor factors that could affect the purification results. Mussels were sampled from two different production areas. The presence or absence of parasites was confirmed by cytological test. Both groups of parasitized and non-parasitized mussels were contaminated with E.coli: they were then sampled for microbiological analyses and tested for biomarkers for up to 70 hours of purification. Parasitized and non-parasitized molluscs did not show any differences in levels of E. coli after 12, 24, 36, 48 and 70 hours of depuration. In relation to biomarkers, mussels seem to react to Lysosomal membrane stability in presence of Marteilia. The present study shows that the presence of Marteilia spp. does not affect the purification rate of mussels

    Hyperspectral reflectance measurements from UAS under intermittent clouds: Correcting irradiance measurements for sensor tilt

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    One great advantage of optical hyperspectral remote sensing from unmanned aerial systems (UAS) compared to satellite missions is the possibility to fly and collect data below clouds. The most typical scenario is flying below intermittent clouds and under turbulent conditions, which causes tilting of the platform. This study aims to advance hyperspectral imaging from UAS in most weather conditions by addressing two challenges: (i) the radiometric and spectral calibrations of miniaturized hyperspectral sensors; and (ii) tilting effects on measured downwelling irradiance. We developed a novel method to correct the downwelling irradiance data for tilting effects. It uses a hybrid approach of minimizing measured irradiance variations for constant irradiance periods and spectral unmixing, to calculate the spectral diffuse irradiance fraction for all irradiance measurements within a flight. It only requires the platform's attitude data and a standard incoming light sensor. We demonstrated the method at the Palo Verde National Park wetlands in Costa Rica, a highly biodiverse area. Our results showed that the downwelling irradiance correction method reduced systematic shifts caused by a change in flight direction of the UAS, by 87% and achieving a deviation of 2.78% relative to a on ground reference in terms of broadband irradiance. High frequency (< 3 s) irradiance variations caused by high-frequency tilting movements of the UAS were reduced by up to 71%. Our complete spectral and radiometric calibration and irradiance correction can significantly remove typical striped illumination artifacts in the surface reflectance-factor map product. The possibility of collecting precise hyperspectral reflectance-factor data from UAS under varying cloud cover makes it more operational for environmental monitoring or precision agriculture applications, being an important step in advancing hyperspectral imaging from UAS.Innovation Fund Denmark/[7048-00001B]/IFD/DinamarcaAgricultural Water Innovations in the Tropics/[]/AgWIT/CanadáUniversidad de Costa Rica/[805-C0-603]/UCR/Costa RicaUCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Físic

    GINGER

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    In this paper, we outline the scientific objectives, the experimental layout, and the collaborations envisaged for the GINGER (Gyroscopes IN GEneral Relativity) project. The GINGER project brings together different scientific disciplines aiming at building an array of Ring Laser Gyroscopes (RLGs), exploiting the Sagnac effect, to measure continuously, with sensitivity better than picorad/ s, large bandwidth (ca. 1 kHz), and high dynamic range, the absolute angular rotation rate of the Earth. In the paper, we address the feasibility of the apparatus with respect to the ambitious specifications above, as well as prove how such an apparatus, which will be able to detect strong Earthquakes, very weak geodetic signals, as well as general relativity effects like Lense-Thirring and De Sitter, will help scientific advancements in Theoretical Physics, Geophysics, and Geodesy, among other scientific fields.Comment: 21 pages, 9 figure

    Initial experience with the CDF SVT trigger

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    The Collider Detector at Fermilab (CDF) Silicon Vertex Tracker (SVT) is a device that works inside the CDF Level 2 trigger to find and fit tracks in real time using the central silicon vertex detector information. SVT starts from tracks found by the Level 1 central chamber fast trigger and adds the silicon information to compute transverse track parameters with offline quality in about . The CDF SVT is fully installed and functional and has been exercised with real data during the spring and summer 2001. It is a complex digital device of more than 100 VME boards that performs a dramatic data reduction (only about one event in a thousand is accepted by the trigger). Diagnosing rare failures poses a special challenge and SVT internal data flow is monitored by dedicated hardware and software. This paper briefly covers the SVT architecture and design and reports on the SVT building/commissioning experience (hardware and software) and on the first results from the initial running

    Position Paper on Water, Energy, Food and Ecosystem (WEFE) Nexus and Sustainable development Goals (SDGs)

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    The EU and the international community is realising that the Water, Energy, Food and Ecosystem components are interlinked and require a joint planning in order to meet the daunting global challenges related to Water, Energy and Food security and maintaining the ecosystem health and in this way, reach the SDGs. If not dealt with, the world will not be able to meet the demand for water, energy and food in a not too far future and, in any case, in a not sustainable way. The strain on the ecosystems resulting from unsustainable single-sector planning will lead to increasing poverty, inequality and instability. The Nexus approach is fully aligned with and supportive of the EU Consensus on Development. Key elements of the Consensus will require collaborative efforts across sectors in ways that can be supported/implemented by a Nexus approach. In this way, transparent and accountable decision-making, involving the civil society is key and common to the European Consensus on Development and the Nexus approach. The Nexus approach will support the implementation of the SDG in particular SDG 2 (Food), SDG 6 (Water) and SDG 7 (Energy), but most SDGs have elements that link to food, water and energy in one or other way, and will benefit from a Nexus approach. The SDGs are designed to be cross-cutting and be implemented together, which is also reflected in a WEFE Nexus approach. A Nexus approach offers a sustainable way of addressing the effects of Climate Change and increase resilience. The WEFE Nexus has in it the main drivers of climate change (water, energy and food security) and the main affected sectors (water and the environment). Decisions around policy, infrastructure, … developed based on the WEFE Nexus assessments will be suitable as elements of climate change mitigation and adaptation. In fact, it is difficult to imagine solutions to the climate change issue that are not built on a form of Nexus approach. The Nexus approach is being implemented around the world, as examples in the literature demonstrate. These examples together with more examples from EU and member state development cooperation will help build experience that can be consolidated and become an important contribution to a Toolkit for WEFE Nexus Implementation. From the expert discussions, it appears that because of the novelty of the approach, a Toolkit will be an important element in getting the Nexus approach widely used. This should build on experiences from practical examples of NEXUS projects or similar inter-sectorial collaboration projects; and, there are already policy, regulation and practical experience to allow institutions and countries to start applying the Nexus concept.JRC.D.2-Water and Marine Resource

    On whether vegetation could contribute to major climate change mitigation efforts: forestry for carbon credits or carbon credits for forestry? A multi-criteria decision support model for forest carbon offsets

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    The transition towards a less carbon-intensive society has been initiated. Still, the international climate policy arena is seeking a significant mitigation strategy. Land-Use, Land-Use Change, and Forestry (LULUCF) activities have been acknowledged to represent both a valid carbon dioxide reduction option through biological removal and a considerable source of greenhouse gas emissions at the same time, especially through deforestation. However, forest carbon credits are not being extensively purchased by government tendering and multinational banks. Moreover, the compliance market is generally failing to support sustainable development carbon projects while voluntary offsets appear in that sense more successful, yet less stringent. Therefore, this thesis questions the adequacy of the project-based approach to biological removal and points out other non-technical uncertainties prior to the scientific understanding of carbon sequestration. As a consequence of the inherent complexity of the socio-ecological system, it is argued that the currently low contribution of land-use offsets to climate change mitigation has been determined by the biased definition of win-win goals in the first place, rather than by wrongful implementation. The plausible conditions for the market development of forest carbon offsets have been extracted by means of formative scenario analysis, i.e. the qualitative description of how present potentials could be deployed into alternative futures. Whereas project quality and market price compete on different dimensions, several bonds among system variables seem to limit the degree of intervention over aspects such as standardisation and demand activity. As a result, forest carbon credits do not appear bound for much more than today's state of the art. Natural carbon sources alike, general recommendations to policy making translate into decoupling sinks from market-based mitigation strategies. Besides scenario construction modelling, the paper contributes with preliminary insights into the relationship between probability and desirability of different scenarios according to stakeholders' decision criteria

    African Labor Histories

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    Introduction: African Labor Histories

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