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The challenges of reusing mining and mineral-processing wastes   总被引:2,自引:0,他引:2  
Mining and mineral-processing wastes are one of the world's largest chronic waste concerns. Their reuse should be included in future sustainable development plans, but the potential impacts on a number of environmental processes are highly variable and must be thoroughly assessed. The chemical composition and geotechnical properties of the source rock determine which uses are most appropriate and whether reuse is economically feasible. If properly evaluated, mining waste can be reused to reextract minerals, provide additional fuel for power plants, supply construction materials, and repair surface and subsurface land structures altered by mining activities themselves.  相似文献   
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A 19-month-old Standardbred colt was donated to the University of Pennsylvania School of Veterinary Medicine with a suspicion of intersexuality. The anal−genital distance and penis were normal, and there was no evidence of intersexuality, but the colt was bilaterally cryptorchid. Several aspects of the colt's behavior appeared unusual, including general temperament and behavior described as sympathetically dull and affable. With herd mates, the colt appeared slow to perceive or to learn the usual intraspecies social cues. An atypical gait characterized by intermittent unnatural shuffle of the hind limbs, sliding them along in short rhythmic strides for 3 to 10 seconds at a time was noted at times when a horse might normally transition from a slow walk to a fast walk or a slow trot. Occasionally the colt exhibited slight protrusion of the tongue through the teeth and lips with jaw movements and smacking of the tongue against the teeth as if struggling to retract the tongue to the normal position. Evaluation of the karyotype combined with fluorescent in situ hybridization (FISH) revealed an abnormal male karyotype showing trisomy of chromosome 27 (65, XY + 27). The colt was euthanized at 24 months of age, and a necropsy revealed no significant abnormalities. This case of trisomy was not associated with developmental abnormalities described in other rare reports of trisomy in horses; however, some features were strikingly similar to that of humans with trisomy 21. FISH was demonstrated to be an excellent method for correct identification of equine chromosomes.  相似文献   
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OBJECTIVE: The aim of this study was to determine the food sources and acquisition practices used by homeless youth in Adelaide. This work is part of a larger study that aimed to examine the extent and nature of food insecurity among homeless youth. DESIGN: Cross-sectional design involving quantitative and qualitative methods. SETTING: Four health and welfare inner-city agencies serving homeless youth in Adelaide, South Australia. SUBJECTS: A sample of 150 homeless youth aged between 15 and 24 years recruited from these agencies. Fifteen were selected via snowball sampling for interview. RESULTS: Use of welfare food sources was high (63%). Food from welfare agencies was supplemented by unorthodox food acquisition methods such as theft (65%), begging for money for food (61%), begging for food items (44%) and asking for help from friends and relatives (34%). Reasons given for non-usage of welfare food services included affordability, access, being too busy, shame or embarrassment. CONCLUSIONS: Food insecurity is a salient issue for some homeless youth in Adelaide. Clarifying food acquisition practices of food-insecure homeless youth is essential for rational planning and improvement of food-related services to meet their needs. Such an understanding also underpins the development of broader public policy responses that improve individual and household skills and resources to acquire food and ensure food security. Nutrition professionals, welfare professionals and policy-makers need to work sensitively with welfare food agencies and others to improve food access and food security for homeless youth.  相似文献   
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Basic vegetative period(BVP) is an important trait for determining flowering time and adaptation to variable environments.A short BVP barley mutant is about 30 d shorter than its wild type.Genetic analysis using 557 F 2 individuals revealed that the short BVP is governed by a single recessive gene(BVP-1) and was further validated in 2 090 F 3 individuals.The BVP-1 gene was first mapped to barley chromosome 1H using SSR markers.Comparative genomic analysis demonstrated that the chromosome region of BVP-1 is syntenic to rice chromosome 5 and Brachypodium chromosome 2.Barley ESTs/genes were identified after comparison with candidate genes in rice and Brachypodium;seven new gene-specific markers were developed and mapped in the mapping populations.The BVP-1 gene co-segregated with the Mot1 and Ftsh4 genes and was flanked by the gene-specific markers AK252360(0.2 cM) and CA608558(0.5 cM).Further analysis demonstrated that barley and wheat share the same short BVP gene controlling early flowering.  相似文献   
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分析了省属农业高校经费困难的现状与原因,提出了克服困难的对策。  相似文献   
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