148 research outputs found

    Sextant sighting performance in measuring the angle between a stationary simulated star and a stationary blinking light

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    Sextant sighting performance in measuring angle between stationary simulated star and stationary blinking ligh

    Reducing Global Warming and Adapting to Climate Change: The Potential of Organic Agriculture

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    Climate change mitigation is urgent and adaptation to climate change is crucial, particularly in agriculture, where food security is at stake. Agriculture, currently responsible for 20-30% of global greenhouse gas emissions counting direct and indirect agricultural emissions), can however contribute to both climate change mitigation and adaptation. The main mitigation potential lies in the capacity of agricultural soils to sequester CO2 through building organic matter. This potential can be realized by employing sustainable agricultural practices, such as those commonly found within organic farming systems. Examples of these practices are the use of organic fertilizers and crop rotations including legumes leys and cover crops. Mitigation is also achieved in organic agriculture through the avoidance of open biomass burning and the avoidance of synthetic fertilizers and the related production emissions from fossil fuels. Common organic practices also contribute to adaptation. Building soil organic matter increases water retention capacity, and creates more stabile, fertile soils, thus reducing vulnerability to drought, extreme precipitation events, floods and water logging. Adaptation is further supported by increased agro-ecosystem diversity of organic farms, due to reduced nitrogen inputs and the absence of chemical pesticides. The high diversity together with the lower input costs of organic agriculture is key in reducing production risks associated with extreme weather events. All these advantageous practices are not exclusive to organic agriculture. However, they are core parts of the organic production system, in contrast to most non-organic agriculture, where they play a minor role only. Mitigation in agriculture cannot be restricted to the agricultural sector alone, though. Consumer behaviour strongly influences agricultural production systems, and thus their mitigation potential. Significant factors are meat consumption and food wastage. Any discussion on mitigation climate change in agriculture needs to address the entire food chain and needs to be linked to general sustainable development strategies. The main challenges to climate change mitigation and adaptation in organic agriculture and agriculture in general concern a)the understanding of some of the basic processes, such as the interaction of N2O emissions and soil carbon sequestration, contributions of roots to soil carbon sequestration and the life-cycle emissions of organic fertilizers such as compost; b) approaches for emissions accounting that adequately represent agricultural production systems with multiple and diverse outputs and that also encompass ecosystem services; c) the identification and implementation of most adequate policy frameworks for supporting mitigation and adaptation in agriculture, i.e: not putting systemic approaches at a disadvantage due to difficulties in the quantification of emissions, and in their allocation to single products; d) how to assure that the current focus on mitigation does not lead to neglect of the other sustainability aspects of agriculture, such as pesticide loads, eutrophication, acidification or soil erosion and e) the question how to address consumer behaviour and how to utilize the mitigation potential of changes in consumption patterns

    Sextant Sighting Performance in the Ames Midcourse Navigation and Guidance Simulator

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    Midcourse navigation and guidance simulator - sextant sighting performance in simulated environmen

    Greenhouse gas emissions and energy use in UK-grown short-day strawberry (Fragaria xananassa Duch) crops

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    Original article can be found at: http://journals.cambridge.org/ Copyright Cambridge University PressReducing greenhouse gas emissions and optimizing energy consumption are important for mitigating climate change and improving resource use efficiency. Strawberry (Fragaria xananassa Duch) crops are a key component of the UK soft fruit sector and potentially resource-intensive crops. This is the first study to undertake a detailed environmental impact assessment of all methods of UK strawberry production. A total of 14 systems with six additional sub-systems grown for between 1 and 3 years were identified. They were defined by the growing of short-day (Junebearer) or everbearer varieties, organic production, covering with polytunnels or grown in the open, soil-grown (with or without fumigation) or container-grown (with peat or coir substrate) and summer or spring planted. Pre-harvest, the global warming potential varied between 1·5 and 10·3 t CO2 equiv/ha/crop or 0·13 and 1·14 t CO2 equiv/t of class 1 fruit. Key factors included the use of tunnels, mulch and irrigation, sterilization of soil with fumigants and the use of peat substrate. Seasonal crops without covers grown where rotation of sufficient length reduced Verticillium (system 4) were the most efficient. System 4a (that did not use mulch) emitted 0·13 t CO2 equiv/t of class 1 fruit. A second or third cropping year in soil-grown systems prolonged the effect of mulch and soil fumigants. Greenhouse gases from system 4 (with mulch) averaged 0·30 t CO2 equiv/t of class 1 fruit after 3 years of cropping compared to 0·63 and 0·36 t CO2 equiv/t after 1 and 2 years, respectively.Peer reviewe

    A Pragmatic Assessment of Government Support for Organic Agriculture in Ireland

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    Drawing on a pragmatic approach, this paper provides an analysis of governmental support for organic farming in Ireland. There are varying levels of encouragement and programmes provided to farmers in their conversion from conventional to organic production, and in their maintenance of organic production. Support policies vary across regions and are linked to European Union legislation, thus it is challenging to document the many types of support in place. This research investigates relevant technical, financial, and policy support available to organic farmers in Ireland. This exploratory study develops an assessment of Ireland within eight key categories of organic agricultural support: leadership, policy, research, technical support, financial support, marketing and promotion, education and information, and future developments. Information and data from the Irish Department of Agriculture, Fisheries and Food (DAFF), the Irish Agriculture and Food Development Authority (Teagasc), and other governmental and semi-governmental agencies were utilized to assess the level of support in each category. Following the pragmatic approach, this assessment provides key findings which allow policymakers, organizations and citizens to better understand the current situation and set a path for the future development of organic farming in Ireland

    North-east sector of the Greenland Ice Sheet to undergo the greatest inland expansion of supraglacial lakes during the 21st century

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    The formation and rapid drainage of supraglacial lakes (SGL) influences the mass balance and dynamics of the Greenland Ice Sheet (GrIS). Although SGLs are expected to spread inland during the 21st century due to atmospheric warming, less is known about their future spatial distribution and volume. We use GrIS surface elevation model and regional climate model outputs to show that at the end of the 21st century (2070-2099) approximately 9.8 ± 3.9 km3 (+113% compared to 1980-2009) and 12.6 ± 5 km3 (+174%) of meltwater could be stored in SGLs under moderate (RCP 4.5) and high (RCP 8.5) climate change scenarios respectively. The largest increase is expected in the north-eastern sector of the GrIS (191% in RCP 4.5 and 320% in RCP 8.5), whereas in west Greenland, where the most SGLs are currently observed, the future increase will be relatively moderate (55% in RCP 4.5 and 68% in RCP 8.5)

    How COVID-19 impacted child and family health and healthcare: a mixed-methods study incorporating family voices

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    To describe how social disruptions caused by the COVID-19 pandemic impacted child access to healthcare and child health behaviors in 2020. We used mixed-methods to conduct surveys and in-depth interviews with English- and Spanish-speaking parents of young children from five geographic regions in the USA. Participants completed the COVID-19 Exposure and Family Impact Survey (CEFIS). Semistructured telephone interviews were conducted between August and October 2020. Of the 72 parents interviewed, 45.8% of participants were Hispanic, 20.8% Black (non-Hispanic), and 19.4% White (non-Hispanic). On the CEFIS, the average (SD) number of social/family disruptions reported was 10.5 (3.8) out of 25. Qualitative analysis revealed multiple levels of themes that influenced accessing healthcare during the pandemic, including two broad contextual themes: (a) lack of trustworthiness of medical system/governmental organizations, and (b) uncertainty due to lack of consistency across multiple sources of information. This context influenced two themes that shaped the social and emotional environments in which participants accessed healthcare: (a) fear and anxiety and (b) social isolation. However, the pandemic also had some positive impacts on families: over 80% indicated that the pandemic made it "a lot"or "a little"better to care for their new infants. Social and family disruptions due to COVID-19 were common. These disruptions contributed to social isolation and fear, and adversely impacted multiple aspects of child and family health and access to healthcare. Some parents of infants reported improvements in specific health domains such as parenting, possibly due to spending more time together

    Understanding and Predicting Human made and Distributed Environmental Toxins on a Molecular Level

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    There are a wide range of chemicals and chemical mixtures that humans use to control plants, animals and insects. Many of these are poisons and can attack a number of physiological systems. Algaecides, Antifouling agents, Antimicrobials, Attractants, Biopesticides, Biocides Disinfectants and sanitizers, Fungicides, Fumigants, Herbicides, Insecticides, Miticides, Microbial pesticides, Molluscicides, Nematicides; Ovicides, Pheromones, Repellents, Rodenticides as well as some chemical defenses used by plants. Six biological parameters are calculated for dozens of these molecules. (GPCR ligand, Ion channel modulator, Kinase inhibitor, Nuclear receptor ligand, Protease inhibitor, Enzyme inhibitor) to help understand what impact they might have on humans and other mammals. For example, G protein-coupled receptors (GPCRs), have several names including G protein linked receptors (GPLR). They are a family of protein receptors located on the cell membrane that detect molecular species that can initiate or impact cellular responses. G protein-coupled receptors have been correlated with a large number of diseases including cancer, antibiotics, HIV and Alzheimer’s, are a target of one third of all medicinal drugs currently being utilized. This presentation will identify the best and the worst of chemicals used and make a suggestion for each to lower their negative impact
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