622,505 research outputs found

    Paying for Biodiversity Conservation Services in Agricultural Landscapes

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    Adoption of improved silvopastoral practices in degraded pasture areas is thought to provide valuable local and global environmental benefits, including biodiversity conservation, However, these practices are insufficiently attractive to individual land users for them to adopt them spontaneously, particularly due to their high initial costs. This paper describes the contract mechanism developed for the Regional Integrated Silvopastoral Ecosystem Management Project, which is being implemented with financing from the Global Environment Facility (GEF). The project is testing the use of the payment-for-service mechanism to encourage the adoption of silvopastoral practices in three countries of Central and South America: Colombia, Costa Rica, and Nicaragua. The project has created a mechanism that pays land users for the global environmental services they are generating, so that the additional income stream makes the proposed practices privately profitable. Designing the mechanism required addressing issues such as (1) measuring the actual amount of environmental services being provided, so that appropriate payments can be made; (2) providing payments in a way that resulted in the desired change in land use; and (3) avoiding the creation of perverse incentives (for example, for land users to cut down existing trees so as to qualify for additional payments for tree planting). Two variants of the proposed payment mechanism are being tested, with participating land users assigned randomly to one or the other. The project also includes extensive monitoring of the effectiveness of each mechanism in stimulating adoption of the proposed measures and of the resulting impact on environmental services and on household welfare. These features, together with the three-country approach, will provide in the coming years a very rich dataset for testing the use of contract mechanisms for biodiversity conservation.Payments for Environmental Services, Contract design, Biodiversity, Conservation, Silvopastoral, Agroforestry

    Management of pest insects and plant diseases by non-transformative RNAi

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    Since the discovery of RNA interference (RNAi), scientists have made significant progress towards the development of this unique technology for crop protection. The RNAi mechanism works at the mRNA level by exploiting a sequence-dependent mode of action with high target specificity due to the design of complementary dsRNA molecules, allowing growers to target pests more precisely compared to conventional agrochemicals. The delivery of RNAi through transgenic plants is now a reality with some products currently in the market. Conversely, it is also expected that more RNA-based products reach the market as non-transformative alternatives. For instance, topically applied dsRNA/siRNA (SIGS - Spray Induced Gene Silencing) has attracted attention due to its feasibility and low cost compared to transgenic plants. Once on the leaf surface, dsRNAs can move directly to target pest cells (e.g., insects or pathogens) or can be taken up indirectly by plant cells to then be transferred into the pest cells. Water-soluble formulations containing pesticidal dsRNA provide alternatives, especially in some cases where plant transformation is not possible or takes years and cost millions to be developed (e.g., perennial crops). The ever-growing understanding of the RNAi mechanism and its limitations has allowed scientists to develop non-transgenic approaches such as trunk injection, soaking, and irrigation. While the technology has been considered promising for pest management, some issues such as RNAi efficiency, dsRNA degradation, environmental risk assessments, and resistance evolution still need to be addressed. Here, our main goal is to review some possible strategies for non-transgenic delivery systems, addressing important issues related to the use of this technology

    Autonomous support for microorganism research in space

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    A preliminary design for performing on orbit, autonomous research on microorganisms and cultured cells/tissues is presented. An understanding of gravity and its effects on cells is crucial for space exploration as well as for terrestrial applications. The payload is designed to be compatible with the Commercial Experiment Transporter (COMET) launch vehicle, an orbiter middeck locker interface, and with Space Station Freedom. Uplink/downlink capabilities and sample return through controlled reentry are available for all carriers. Autonomous testing activities are preprogrammed with in-flight reprogrammability. Sensors for monitoring temperature, pH, light, gravity levels, vibrations, and radiation are provided for environmental regulation and experimental data collection. Additional experimental data acquisition includes optical density measurement, microscopy, video, and film photography. On-board full data storage capabilities are provided. A fluid transfer mechanism is utilized for inoculation, sampling, and nutrient replenishment of experiment cultures. In addition to payload design, representative experiments were developed to ensure scientific objectives remained compatible with hardware capabilities. The project is defined to provide biological data pertinent to extended duration crewed space flight including crew health issues and development of a Controlled Ecological Life Support System (CELSS). In addition, opportunities are opened for investigations leading to commercial applications of space, such as pharmaceutical development, modeling of terrestrial diseases, and material processing

    Design and Implementation of A Monitoring System for Geological Archives

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    A monitoring system for geological archives with TCP/IP network communication is designed in this research to address wide distribution range, long distance, slow data updating, and difficult maintenance of city and county geological archives. The designed system uses the single chip STC11F32XE and the Ethernet control chip RTL8019AS as a hardware platform. The hardware design scheme, software design method, and the main programming flowchart of the geological archive monitoring unit were presented, and a specific data test was carried out. This monitoring system not only monitors and controls temperature, humidity, ponding, power supply, and other environmental data in geological archives, but also realizes geological data transmission between city (county) and provincial geological archives. In addition, this system is designed with a GSM warning mechanism, which could accelerate the quick response mechanism of the system. The entire monitoring system is accessed through the provincial environmental resources website with a fixed IP address. To ensure standardization of the monitoring system, the data transmission standard of the application layer used the associated standards of the Ministry of National Land and Resources. The entire system design improves the storage environment of the geological data effectively. It provides important data support to solve inconsistencies between provincial and city (county) geological data, as well as ensures scientific management of geological issues

    Sample Acquisition and Instrument Deployment (SAID)

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    This report details the interim progress for contract NASW-4818, Sample Acquisition and Instrument Deployment (SAID), a robotic system for deploying science instruments and acquiring samples for analysis. The system is a conventional four degree of freedom manipulator 2 meters in length. A baseline design has been achieved through analysis and trade studies. The design considers environmental operating conditions on the surface of Mars, as well as volume constraints on proposed Mars landers. Control issues have also been studied, and simulations of joint and tip movements have been performed. A passively braked shape memory actuator with the ability to measure load has been developed. The wrist also contains a mechanism which locks the lid output to the bucket so that objects can be grasped and released for instrument deployment. The wrist actuator has been tested for operational power and mechanical functionality at Mars environmental conditions. The torque which the actuator can produce has been measured. Also, testing in Mars analogous soils has been performed

    The roles of sustainability assessment systems in delivering sustainable construction

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    Sustainable development in construction has increasingly gained momentum over the years due to a growing public concern and enforcement of government policy. A variety of sustainability standards and systems have therefore emerged in the current construction industry to provide a means for assessment, ranging from Leadership in Energy and Environmental Design (LEED), Building Research Establishment Environmental Assessment Method (BREEAM), National Australian Building Environmental Rating System (NABERS) to ISO14001. In Hong Kong, LEED and Building Environmental Assessment Method (BEAM Plus) are the mechanism preferred by practitioners for their sustainable buildings certification. This paper will review and examine the roles of the sustainability performance assessment standards in delivering sustainability in construction. Interviews were conducted to explore various viewpoints on sustainability rating systems from different stakeholders. Apart from serving as a guideline for practitioners, sustainability systems can help to gauge the sustainable performance of individual buildings by using transparent and objectively comprehensible metrics. Nevertheless, there is a lack of focus on the post occupancy evaluation and soft issues in the current sustainability assessment systems. By taking into consideration soft issues and those performance goals in operational management, a more holistic and comprehensive assessment approach can be provided for evaluating sustainable construction performance. The potential of the green building rating systems being abused for marketing purpose can also be reduced with a series of periodic assessments during the operational life cycle. These improved sustainability assessment systems can therefore help to reframe the expectations and the strategies of construction stakeholders in pursuing the true goals of sustainable development in construction.published_or_final_versio
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