97 research outputs found

    Payments for Watershed Services: An Application to Irrigation Pricing in the El Angel Watershed, Carchi, Ecuador

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    Water scarcity is increasingly viewed as the principal constraint limiting agricultural production and human livelihood improvement in the rural areas of many developing countries. Policies that encourage more efficient and equitable water use - including the introduction of incentive-based water pricing systems - are an important challenge. This paper reports the results of a mathematical programming model which was constructed for the El Angel watershed in northern Ecuador with the goal of exploring the effects of several water pricing alternatives. The model incorporates farmers' crop and pasture planting and resource allocation decisions, based on maximizing regional gross margin subject to land, water, labor, seasonal, food security and other constraints. Four water pricing scenarios are examined. The results show that adequate water resources currently exist to permit a reallocation of water within the watershed, which would generate higher regional production and incomes. Several water pricing alternatives are explored which would discipline water use in those parts of the watershed where water is currently overused and unregulated. Incomes could be significantly increased in currently waterscarce parts of the watershed while generating only small reductions in production and incomes in water-abundant zones. While tradeoffs exist among economic, environmental and employment goals, significant net gains are achievable. If a differentiated system of water prices is considered to be unrealistic, a system of single seasonal prices would likely generate reduced, though significant, benefits. Introducing a system of comprehensive water charges would likely create similar benefits in other developing country watersheds facing similar resource constraints.Resource /Energy Economics and Policy,

    Artificial Neural Networks for Control of a Grid-Connected Rectifier/Inverter Under Disturbance, Dynamic and Power Converter Switching Conditions

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    Three-phase grid-connected converters are widely used in renewable and electric power system applications. Traditionally, grid-connected converters are controlled with standard decoupled d-q vector control mechanisms. However, recent studies indicate that such mechanisms show limitations in their applicability to dynamic systems. This paper investigates how to mitigate such restrictions using a neural network to control a grid-connected rectifier/inverter. The neural network implements a dynamic programming algorithm and is trained by using backpropagation through time. To enhance performance and stability under disturbance, additional strategies are adopted, including the use of integrals of error signals to the network inputs and the introduction of grid disturbance voltage to the outputs of a well-trained network. The performance of the neural-network controller is studied under typical vector control conditions and compared against conventional vector control methods, which demonstrates that the neural vector control strategy proposed in this paper is effective. Even in dynamic and power converter switching environments, the neural vector controller shows strong ability to trace rapidly changing reference commands, tolerate system disturbances, and satisfy control requirements for a faulted power system

    Public awareness and perceptions of ocean plastic pollution and support for solutions in the United States

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    We conducted a nationally-representative survey of United States (U.S.) adults (n=1,960) in 2021 to gather insights on the knowledge, perceptions, and concerns about threats to the ocean, with a specific focus on plastics and microplastic pollution. Responses from the U.S. adult survey group were compared to a group of highly-engaged, Ocean Conservancy members who are very attuned to ocean issues (n=882). Ocean Conservancy is a U.S.-based nonprofit environmental advocacy group working to protect the ocean from today’s greatest challenges. Plastic pollution was the primary ocean concern identified by both U.S. adults and Ocean Conservancy members, surpassing eight other threat categories including oil spills, chemical and nutrient pollution, and climate change. Broad concern was reported for both study groups about the impacts of ocean plastics on marine wildlife, with human health and coastal community impact concerns being less prominent. About half of U.S. adults and 90% of Ocean Conservancy members had heard of microplastics. Both study groups indicated widespread support for microplastic pollution prevention measures in the U.S. and believed industry to be most responsible for taking action to address it. Ocean Conservancy members were generally better informed and more concerned about plastic pollution impacts and microplastics than U.S. adults and reported significantly greater levels of personal action to reduce their plastic footprint when compared to U.S. adults. In general, U.S. adults reported a willingness to refuse single-use plastics, but less frequently brought personal food containers to restaurants for takeout, or contacted local representatives or businesses about reducing plastic waste and pollution. Overall, our survey results provide new insights about public understanding of ocean threats and plastic pollution, willingness to participate in individual plastic-reduction actions, and support for needed solutions

    Platelets Regulate Pulmonary Inflammation and Tissue Destruction in Tuberculosis.

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    RATIONALE: Platelets may interact with the immune system in tuberculosis (TB) to regulate human inflammatory responses that lead to morbidity and spread of infection. OBJECTIVES: To identify a functional role of platelets in the innate inflammatory and matrix-degrading response in TB. METHODS: Markers of platelet activation were examined in plasma from 50 patients with TB before treatment and 50 control subjects. Twenty-five patients were followed longitudinally. Platelet-monocyte interactions were studied in a coculture model infected with live, virulent Mycobacterium tuberculosis (M.tb) and dissected using qRT-PCR, Luminex multiplex arrays, matrix degradation assays, and colony counts. Immunohistochemistry detected CD41 (cluster of differentiation 41) expression in a pulmonary TB murine model, and secreted platelet factors were measured in BAL fluid from 15 patients with TB and matched control subjects. MEASUREMENTS AND MAIN RESULTS: Five of six platelet-associated mediators were upregulated in plasma of patients with TB compared with control subjects, with concentrations returning to baseline by Day 60 of treatment. Gene expression of the monocyte collagenase MMP-1 (matrix metalloproteinase-1) was upregulated by platelets in M.tb infection. Platelets also enhanced M.tb-induced MMP-1 and -10 secretion, which drove type I collagen degradation. Platelets increased monocyte IL-1 and IL-10 and decreased IL-12 and MDC (monocyte-derived chemokine; also known as CCL-22) secretion, as consistent with an M2 monocyte phenotype. Monocyte killing of intracellular M.tb was decreased. In the lung, platelets were detected in a TB mouse model, and secreted platelet mediators were upregulated in human BAL fluid and correlated with MMP and IL-1β concentrations. CONCLUSIONS: Platelets drive a proinflammatory, tissue-degrading phenotype in TB

    Sperm collection and storage for the sustainable management of amphibian biodiversity

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    Current rates of biodiversity loss pose an unprecedented challenge to the conservation community, particularly with amphibians and freshwater fish as the most threatened vertebrates. An increasing number of environmental challenges, including habitat loss, pathogens, and global warming, demand a global response toward the sustainable management of ecosystems and their biodiversity. Conservation Breeding Programs (CBPs) are needed for the sustainable management of amphibian species threatened with extinction. CBPs support species survival while increasing public awareness and political influence. Current CBPs only cater for 10% of the almost 500 amphibian species in need. However, the use of sperm storage to increase efficiency and reliability, along with an increased number of CBPs, offer the potential to significantly reduce species loss. The establishment and refinement of techniques over the last two decades, for the collection and storage of amphibian spermatozoa, gives confidence for their use in CBPs and other biotechnical applications. Cryopreserved spermatozoa has produced breeding pairs of frogs and salamanders and the stage is set for Lifecycle Proof of Concept Programs that use cryopreserved sperm in CBPs along with repopulation, supplementation, and translocation programs. The application of cryopreserved sperm in CBPs, is complimentary to but separate from archival gene banking and general cell and tissue storage. However, where appropriate amphibian sperm banking should be integrated into other global biobanking projects, especially those for fish, and those that include the use of cryopreserved material for genomics and other research. Research over a broader range of amphibian species, and more uniformity in experimental methodology, is needed to inform both theory and application. Genomics is revolutionising our understanding of biological processes and increasingly guiding species conservation through the identification of evolutionary significant units as the conservation focus, and through revealing the intimate relationship between evolutionary history and sperm physiology that ultimately affects the amenability of sperm to refrigerated or frozen storage. In the present review we provide a nascent phylogenetic framework for integration with other research lines to further the potential of amphibian sperm banking

    D\u27Amico Risk Stratification Correlates with Degree of Suspicion of Prostate Cancer on Multiparametric Magnetic Resonance Imaging.

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    PURPOSE: We determined whether there is a correlation between D\u27Amico risk stratification and the degree of suspicion of prostate cancer on multiparametric magnetic resonance imaging based on targeted biopsies done with our electromagnetically tracked magnetic resonance imaging/ultrasound fusion platform. MATERIALS AND METHODS: A total of 101 patients underwent 3 Tesla multiparametric magnetic resonance imaging of the prostate, consisting of T2, dynamic contrast enhanced, diffusion weighted and spectroscopy images in cases suspicious for or with a diagnosis of prostate cancer. All prostate magnetic resonance imaging lesions were then identified and graded by the number of positive modalities, including low-2 or fewer, moderate-3 and high-4 showing suspicion on multiparametric magnetic resonance imaging. The biopsy protocol included standard 12-core biopsy, followed by real-time magnetic resonance imaging/ultrasound fusion targeted biopsies of the suspicious magnetic resonance lesions. Cases and lesions were stratified by the D\u27Amico risk stratification. RESULTS: In this screening population 90.1% of men had a negative digital rectal examination. Mean±SD age was 62.7±8.3 years and median prostate specific antigen was 5.8 ng/ml. Of the cases 54.5% were positive for cancer on protocol biopsy. Chi-square analysis revealed a statistically significant correlation between magnetic resonance suspicion and D\u27Amico risk stratification (p CONCLUSIONS: Our data support the notion that using multiparametric magnetic resonance prostate imaging one may assess the degree of risk associated with magnetic resonance visible lesions in the prostate

    Eruption type probability and eruption source parameters at Cotopaxi and Guagua Pichincha volcanoes (Ecuador) with uncertainty quantification

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    Future occurrence of explosive eruptive activity at Cotopaxi and Guagua Pichincha volcanoes, Ecuador, is assessed probabilistically, utilizing expert elicitation. Eight eruption types were considered for each volcano. Type event probabilities were evaluated for the next eruption at each volcano and for at least one of each type within the next 100 years. For each type, we elicited relevant eruption source parameters (duration, average plume height, and total tephra mass). We investigated the robustness of these elicited evaluations by deriving probability uncertainties using three expert scoring methods. For Cotopaxi, we considered both rhyolitic and andesitic magmas. Elicitation findings indicate that the most probable next eruption type is an andesitic hydrovolcanic/ash-emission (~ 26–44% median probability), which has also the highest median probability of recurring over the next 100 years. However, for the next eruption at Cotopaxi, the average joint probabilities for sub-Plinian or Plinian type eruption is of order 30–40%—a significant chance of a violent explosive event. It is inferred that any Cotopaxi rhyolitic eruption could involve a longer duration and greater erupted mass than an andesitic event, likely producing a prolonged emergency. For Guagua Pichincha, future eruption types are expected to be andesitic/dacitic, and a vulcanian event is judged most probable for the next eruption (median probability ~40–55%); this type is expected to be most frequent over the next 100 years, too. However, there is a substantial probability (possibly >40% in average) that the next eruption could be sub-Plinian or Plinian, with all that implies for hazard levels

    Delivering 21st century Antarctic and Southern Ocean science

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    The Antarctic Roadmap Challenges (ARC) project identified critical requirements to deliver high priority Antarctic research in the 21st century. The ARC project addressed the challenges of enabling technologies, facilitating access, providing logistics and infrastructure, and capitalizing on international co-operation. Technological requirements include: i) innovative automated in situ observing systems, sensors and interoperable platforms (including power demands), ii) realistic and holistic numerical models, iii) enhanced remote sensing and sensors, iv) expanded sample collection and retrieval technologies, and v) greater cyber-infrastructure to process ‘big data’ collection, transmission and analyses while promoting data accessibility. These technologies must be widely available, performance and reliability must be improved and technologies used elsewhere must be applied to the Antarctic. Considerable Antarctic research is field-based, making access to vital geographical targets essential. Future research will require continent- and ocean-wide environmentally responsible access to coastal and interior Antarctica and the Southern Ocean. Year-round access is indispensable. The cost of future Antarctic science is great but there are opportunities for all to participate commensurate with national resources, expertise and interests. The scope of future Antarctic research will necessitate enhanced and inventive interdisciplinary and international collaborations. The full promise of Antarctic science will only be realized if nations act together

    Real-life assessment of chronic rhinosinusitis patients using mobile technology : The mySinusitisCoach project by EUFOREA

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    Background Chronic rhinosinusitis (CRS) is a chronic inflammatory disease associated with a substantial personal and socioeconomic burden. Monitoring of patient-reported outcomes by mobile technology offers the possibility to better understand real-life burden of CRS. Methods This study reports on the cross-sectional evaluation of data of 626 users of mySinusitisCoach (mSC), a mobile application for CRS patients. Patient characteristics of mSC users were analysed as well as the level of disease control based on VAS global rhinosinusitis symptom score and adapted EPOS criteria. Results The mSC cohort represents a heterogeneous group of CRS patients with a diverse pattern of major symptoms. Approximately half of patients reported nasal polyps. 47.3% of all CRS patients were uncontrolled based on evaluation of VAS global rhinosinusitis symptom score compared to 40.9% based on adapted EPOS criteria. The impact of CRS on sleep quality and daily life activities was significantly higher in uncontrolled versus well-controlled patients. Half of patients had a history of FESS (functional endoscopic sinus surgery) and reported lower symptom severity compared to patients without a history of FESS, except for patients with a history of more than 3 procedures. Patients with a history of FESS reported higher VAS levels for impaired smell. Conclusion Real-life data confirm the high disease burden in uncontrolled CRS patients, clearly impacting quality of life. Sinus surgery improves patient-reported outcomes, but not in patients with a history of more than 3 procedures. Mobile technology opens a new era of real-life monitoring, supporting the evolution of care towards precision medicine.Peer reviewe

    A collaboratively derived environmental research agenda for Galapagos

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    Galápagos is one of the most pristine archipelagos in the world and its conservation relies upon research and sensible management. In recent decades both the interest in, and the needs of, the islands have increased, yet the funds and capacity for necessary research have remained limited. It has become, therefore, increasingly important to identify areas of priority research to assist decision-making in Galápagos conservation. This study identified 50 questions considered priorities for future research and management. The exercise involved the collaboration of policy makers, practitioners and researchers from more than 30 different organisations. Initially, 360 people were consulted to generate 781 questions. An established process of preworkshop voting and three rounds to reduce and reword the questions, followed by a two-day workshop, was used to produce the final 50 questions. The most common issues raised by this list of questions were human population growth, climate change and the impact of invasive alien species. These results have already been used by a range of organisations and politicians and are expected to provide the basis for future research on the islands so that its sustainability may be enhanced. </jats:p
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