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The free distribution of seeds and tools is the standard approach to agricultural recovery. The predominance of this approach is partly attributable to the: (1) perception that farmer seed quality is poor, (2) insistence on seed certification, (3) promotion of researcher varieties, (4) misdiagnosis of unavailability, (5) difficulty accessing farmer seed, and (6) support for the commercial seed sector. This paper presents a Seed Security Assessment Framework to distinguish among the causes of seed insecurity and focuses on three principal concepts: seed availability; access to seed; and factors associated with seed utilisation. Using this diagnostic framework, Catholic Relief Services (CRS) has developed a better approach to promoting seed system-based agricultural recovery. It involves a combination of seed voucher distribution and the organization of seed fairs, which bring together a range of sellers from whom the holders of vouchers may purchase seed. This approach is advantageous because it: strengthens farmer seed procurement systems; is cost efficient; in economic terms, has a multiplier effect in the community; is straightforward to plan and implement; allows commercial sector participation; provides an opportunity to promote improved varieties for farmer evaluation; brings together different communities.  相似文献   
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ABSTRACT. Experimental results of cloud seeding in Southwestern Colorado suggest that runoff can be increased by 25 percent over a 3,300 mile area. There is a need to estimate the economic consequences in the Colorado River Basin. The evidence presented suggests that weather modification is an economically feasible means to provide additional water for the basin. Compared with other proposed means of augmenting water supplies, weather modifications appear to be one of the least cost alternatives. A very low proportion of weather modification costs are fixed; thus the program is easily reversible. Also, a relatively small increase in daily precipitation covers the direct costs of operation. Benefits of water produced by weather modification included power production and irrigation of forage crops. In the long run, if additional water is used for higher valued fruit and vegetable production, or for domestic and industrial purposes, its value would rise sharply. Preliminary investigation of extra-market costs and benefits suggests that while they have little effect on the benefit-cost ratio, they may be very important to individuals and groups affected. The distribution of costs and benefits is important as the benefits accrue to downstream users and some of the costs are incurred by Coloradoans. There is a need for further research on the long-run economic effects of weather modification programs, particularly with respect to extra-market factors.  相似文献   
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The objectives of this research were to (1) determine the incidence and prevalence of alcohol and other drug use among motor vehicle crash (MVC) victims admitted to a regional Level-I trauma center, and (2) to examine the utility of using a rapid point-of-collection (POC) drug-testing device to identify MVC patients with drug involvement. Blood and urine specimens were routinely collected per clinical protocol for each MVC victim at the time of admission. Blood alcohol concentration (BAC) levels were determined per standard clinical protocol. Clinical urine specimens were routinely split so that a POC drug-testing device for the detection of commonly abused drugs (Marijuana, Cocaine, Amphetamines, Methamphetamines, and Opiates) could be compared to that of the standard hospital laboratory analysis of each urine specimen (which also included Barbiturates and Benzodiazepines). In the six-month period of this study, nearly two-thirds of trauma center admissions were victims of motor vehicle crashes. During this time, blood and urine was collected from 322 MVC victims. Toxicology results indicated that 59.3% of MVC victims tested positive for either commonly abused drugs or alcohol. More patients tested positive for drug use than tested positive for alcohol, with 33.5% testing positive for drug use only, 15.8% testing positive for alcohol use only, and 9.9% testing positive for both drugs and alcohol. Less than half (45.2%) of the substance-abusing patients in this study would have been identified by an alcohol test alone. After alcohol, marijuana and benzodiazepines were the most frequently detected drugs. Point of collection (POC) test results correlated well with laboratory results and provide important information to initiate rapid intervention/treatment for substance use problems among injured patients.  相似文献   
68.
Effective water quality management of streams in urbanized basins requires identification of the elements of urbanization that contribute most to pollutant concentrations and loads. Drainage connection (the proportion of impervious area directly connected to streams by pipes or lined drains) is proposed as a variable explaining variance in the generally weak relationships between pollutant concentrations and imperviousness. Fifteen small streams draining independent subbasins east of Melbourne, Australia, were sampled for a suite of water quality variables. Geometric mean concentrations of all variables were calculated separately for baseflow and storm events, and these, together with estimates of runoff derived from a rainfall-runoff model, were used to estimate mean annual loads. Patterns of concentrations among the streams were assessed against patterns of imperviousness, drainage connection, unsealed (unpaved) road density, elevation, longitude (all of which were intercorrelated), septic tank density, and basin area. Baseflow and storm event concentrations of dissolved organic carbon (DOC), filterable reactive phosphorus (FRP), total phosphorus (TP) and ammonium, along with electrical conductivity (EC), all increased with imperviousness and its correlates. Hierarchical partitioning showed that DOC, EC, FRP, and storm event TP were independently correlated with drainage connection more strongly than could be explained by chance. Neither pH nor total suspended solids concentrations were strongly correlated with any basin variable. Oxidized and total nitrogen concentrations were most strongly explained by septic tank density. Loads of all variables were strongly correlated with imperviousness and connection. Priority should be given to low-impact urban design, which primarily involves reducing drainage connection, to minimize urbanization-related pollutant impacts on streams.  相似文献   
69.
Can China control the side effects of motor vehicle growth?   总被引:2,自引:0,他引:2  
Motor vehicle growth in China is the fastest in the world. This is placing great strain on the urban environment and causing a rapid increase in oil imports and motor vehicle carbon dioxide emissions. To deal with the environmental and health effects of air pollution, China has adopted a strong motor vehicle pollution control programme and imposed limits on fuel consumption of new light duty vehicles. The article will review these problems and programmes. Special focus will be given to the need to reduce sulphur levels in both gasoline and diesel fuel.  相似文献   
70.
Residual soil nitrate after potato harvest   总被引:1,自引:0,他引:1  
Nitrogen loss by leaching is a major problem, particularly with crops requiring large amounts of N fertilizer. We evaluated the effect of N fertilization and irrigation on residual soil nitrate following potato (Solanum tuberosum L.) harvests in the upper St-John River valley of New Brunswick, Canada. Soil nitrate contents were measured to a 0.90-m depth in three treatments of N fertilization (0, 100, and 250 kg N ha(-1)) at two on-farm sites in 1995, and in four treatments of N fertilization (0, 50, 100, and 250 kg N ha(-1)) at four sites for each of two years (1996 and 1997) with and without supplemental irrigation. Residual soil NO3-N content increased from 33 kg NO3-N ha(-1) in the unfertilized check plots to 160 kg NO3-N ha(-1) when 250 kg N ha(-1) was applied. Across N treatments, residual soil NO3-N contents ranged from 30 to 105 kg NO3-N ha(-1) with irrigation and from 30 to 202 kg NO3-N ha(-1) without irrigation. Residual soil NO3-N content within the surface 0.30 m was related (R2 = 0.94) to the NO3-N content to a 0.90-m depth. Estimates of residual soil NO3-N content at the economically optimum nitrogen fertilizer application (Nop) ranged from 46 to 99 kg NO3-N ha(-1) under irrigated conditions and from 62 to 260 kg NO3-N ha(-1) under nonirrigated conditions, and were lower than the soil NO3-N content measured with 250 kg N ha(-1). We conclude that residual soil NO3-N after harvest can be maintained at a reasonable level (<70 kg NO3-N ha(-1)) when N fertilization is based on the economically optimum N application.  相似文献   
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