1,547 research outputs found

    The Convention on Biological Diversity: Opportunities and Constraints for Agricultural Systems in Canada

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    Biological diversity, or biodiversity, refers to the diversity of life at all levels and the linkages between these different levels (Wilson, 1992). Biodiversity is commonly interpreted at three levels: 1) genetic diversity – the genetic variation provided by species; 2) species diversity – the variety of species within a given area; and 3) ecosystem diversity – the variety of biotic communities and habitats and the diversity within ecosystems at the landscape or regional level. An extensive body of research has shown that biodiversity has intrinsic, ecological, genetic, social, economic, scientific, educational, cultural, recreational and aesthetic value, and that it is essential for the adaptation and evolution of systems and species and for maintaining the life-sustaining systems of the biosphere (Holling et al., 1995). Concerns over biodiversity loss stimulated the initiation of a formal global response, namely the Convention on Biological Diversity(CBD), in 1992. In December of that year, Canada became the first industrialized country to ratify the CBD, which entered into force on December 29th, 1993. It should be noted that while, to date, 187 countries are parties to the CBD, the United States has not ratified and is not a party to the convention. Subsequent to ratifying the CBD, Canada has developed, and continues to develop, a policy framework to help it meet its goals within the CBD. This article evaluates the potential for opportunity and/or constraints for Canadian agricultural systems as parties to the CBD develop programs and policies to meet their biodiversity objectives. The article begins by introducing those parts of the CBD that are relevant for agricultural systems and discusses, in general terms, the Canadian response to the CBD. The article then presents the specific biodiversity initiatives that have been developed by the Canadian government and discusses the potential impact of these initiatives on Canadian agriculture.Environmental Economics and Policy,

    Coronal Alfven waves and the solar wind

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    The observed properties of coronal Alfven waves in the solar wind at 1 AU are briefly reviewed, with some theoretical discussion of their probable effects on the dynamics of the expanding solar corona. It is concluded that coronal Alfven waves can have a major influence on both the small- and large-scale properties of the wind at 1 AU

    Stellar winds driven by Alfven waves

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    Models of stellar winds were considered in which the dynamic expansion of a corona is driven by Alfven waves propagating outward along radial magnetic field lines. In the presence of Alfven waves, a coronal expansion can exist for a broad range of reference conditions which would, in the absence of waves, lead to static configurations. Wind models in which the acceleration mechanism is due to Alfven waves alone and exhibit lower mass fluxes and higher energies per particle are compared to wind models in which the acceleration is due to thermal processes. For example, winds driven by Alfven waves exhibit streaming velocities at infinity which may vary between the escape velocity at the coronal base and the geometrical mean of the escape velocity and the speed of light. Upper and lower limits were derived for the allowed energy fluxes and mass fluxes associated with these winds

    Modeling economic, biophysical, and environmental dynamics of potato production system

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    The adoption and use of diversified cropping practices has become widely accepted by producers. However, the profitability of an enterprise is dependent on the biophysical and economic factors. The biophysical factors determine the enterprise relationship among the various crops, their interactions with the ecosystem, and how each of them fits into the overall management plan. The economic factors determine the relative advantage of each crop and service in the farm plan. Although there have been experimental studies in Canada examining the impacts of rotations on the agronomics of field crops, there is limited research in modeling economic and environmental dynamics of the potato production system. Potato production in Manitoba has rapidly increased in recent years and became the second largest potato producer in Canada producing about 22.2% of the total Canada's potato production as of 2004. Alberta has had similar expansion with the highest yield per acre in Canada. The expansion of potato industry in these two provinces and other parts of Canada has created some concerns about agro-environmental indicators such as water contamination, soil erosion and long-term profitability of potato production practices. The objective of this study was to address some of these concerns and develop a dynamic model that integrates environmental and economic components of potato production systems and estimates sustainability of some of the agricultural practices. A Stella Modeling framework was developed to provide crop production and environmental input to an economic model of potato rotations. The economic performance of different potato rotations ranging from two to four years in duration, and containing potatoes in combination with oilseed, cereal, forage, and legume crops was evaluated based on standard budgeting techniques. Net income was estimated as the income remaining above cash costs (i.e., seed, fertilizer, chemical, fuel and oil, repairs, crop insurance premium, miscellaneous, land taxes, and interest cost on variable inputs), ownership costs (depreciation, interest on investment, and insurance and housing) for machinery and grain storage, and labour. All annual inputs used in each phase of rotation for each management treatment, the type and frequency of field operation, year and replicate including pre-plant activities, tillage, fertilization, planting, insects and pests control, harvesting, storage, and transportation were included in the analysis. Modelling the economics of irrigated potato rotations required input from an agro-environmental model. This agro-environmental model was developed to simulate nutrient dynamics, soil moisture dynamics, soil characteristics and erosion, soil organic matter content, residue decomposition, and crop growth. The economic model takes into account economic factors and costs that are influenced by yield function, nutrients and crop water thus establishing the link between the agro-environmental module and the economic module. Farm operation costs in our model are divided into two categories: dependent costs and base costs. Dependent costs are costs that are controlled by the agro-environmental module, including yield dependent costs, irrigation dependent costs and fertilizer dependent costs. Base costs were developed through experimental evaluation with E-Views and remain constant throughout the rotation. On the agro-environmental side, the model outputs the changes in soil organic matter, soil loss due to erosion, and carbon dioxide emission due to decomposition and mineralization. Results of the model show that changes in these variables are dependent upon the length of, and the crops involved in, the rotation. The economic model results showed highest average net revenue was found in shorter two-year rotations due to the greater frequency of potato.Crop Production/Industries,

    Iris Recognition: The Consequences of Image Compression

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    Iris recognition for human identification is one of the most accurate biometrics, and its employment is expanding globally. The use of portable iris systems, particularly in law enforcement applications, is growing. In many of these applications, the portable device may be required to transmit an iris image or template over a narrow-bandwidth communication channel. Typically, a full resolution image (e.g., VGA) is desired to ensure sufficient pixels across the iris to be confident of accurate recognition results. To minimize the time to transmit a large amount of data over a narrow-bandwidth communication channel, image compression can be used to reduce the file size of the iris image. In other applications, such as the Registered Traveler program, an entire iris image is stored on a smart card, but only 4 kB is allowed for the iris image. For this type of application, image compression is also the solution. This paper investigates the effects of image compression on recognition system performance using a commercial version of the Daugman iris2pi algorithm along with JPEG-2000 compression, and links these to image quality. Using the ICE 2005 iris database, we find that even in the face of significant compression, recognition performance is minimally affected

    Legislative Oversight in the North Dakota State Legislature

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    The purpose of this study is to look at the extent of legislative oversight in the North Dakota State Legislature. The State\u27s legislators meet only once every two years for about four months and the rest of the time they are fulltime private citizens and parttime legislators. Oversight of North Dakota\u27s Executive Branch must be done by legislators who are being pulled in several directions by job, family and constituents. Oversight does not rate high on the priority list in the legislative interim. In order to get an idea of what types of oversight are available to the State\u27s legislators, this study compares congressional oversight to State oversight techniques. The similarities are interesting. While there is quite a bit written about congressional oversight, little study has been done on state oversight. In order to get a handle on oversight methods available to North Dakota\u27s legislators and the methods actually used by them a series of interviews were conducted. Chester Nelson, the Legislative Council\u27s fiscal analyst and auditor was interviewed concerning fiscal oversight available to the State\u27s legislators. John Olsrud, Director of the Legislative Council staff, talked about the role of the council staff in assisting legislators in oversight. And finally, fourteen of the State\u27s legislators were interviewed to determine how they feel about oversight

    Bar-holding prosthetic limb

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    A prosthetic device for below-the-elbow amputees is disclosed. The device has a removable effector, which is attached to the end of an arm cuff. The effector is comprised of a pair of C-shaped members that are oriented so as to face each other. Working in concert, the C-shaped members are able to hold a bar such as a chainsaw handle. A flat spring is fitted around the C-shaped members to hold them together

    Rotationally actuated prosthetic helping hand

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    A prosthetic device has been developed for below-the-elbow amputees. The device consists of a cuff, a stem, a housing, two hook-like fingers, an elastic band for holding the fingers together, and a brace. The fingers are pivotally mounted on a housing that is secured to the amputee's upper arm with the brace. The stem, which also contains a cam, is rotationally mounted within the housing and is secured to the cuff, which fits over the amputee's stump. By rotating the cammed stem between the fingers with the lower arm, the amputee can open and close the fingers

    Sunward-propagating Alfv\'enic fluctuations observed in the heliosphere

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    The mixture/interaction of anti-sunward-propagating Alfv\'enic fluctuations (AFs) and sunward-propagating Alfv\'enic fluctuations (SAFs) is believed to result in the decrease of the Alfv\'enicity of solar wind fluctuations with increasing heliocentric distance. However, SAFs are rarely observed at 1 au and solar wind AFs are found to be generally outward. Using the measurements from Voyager 2 and Wind, we perform a statistical survey of SAFs in the heliosphere inside 6 au. We first report two SAF events observed by Voyager 2. One is in the anti-sunward magnetic sector with a strong positive correlation between the fluctuations of magnetic field and solar wind velocity. The other one is in the sunward magnetic sector with a strong negative magnetic field-velocity correlation. Statistically, the percentage of SAFs increases gradually with heliocentric distance, from about 2.7% at 1.0 au to about 8.7% at 5.5 au. These results provide new clues for understanding the generation mechanism of SAFs
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