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1.
The commercial, welfare and environmental impacts of rearing small colonies of free-range chickens in newly planted woodland at two sites in the UK, during the first 2 years of the enterprise, were investigated. Newly planted rather than established trees were used so that commercially viable species could be planted in a way that would suit the management of the chicken enterprise, and small colonies were used so that farmers wishing to diversify could buy into the system progressively. It was anticipated that marketing a high specification product would provide an immediate income, whilst waiting for the future investment in trees to grow.  相似文献   
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Satellite radar altimetry measurements indicate that the East Antarctic ice-sheet interior north of 81.6 degrees S increased in mass by 45 +/- 7 billion metric tons per year from 1992 to 2003. Comparisons with contemporaneous meteorological model snowfall estimates suggest that the gain in mass was associated with increased precipitation. A gain of this magnitude is enough to slow sea-level rise by 0.12 +/- 0.02 millimeters per year.  相似文献   
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Between 15,000 and 18,000 years ago, large amounts of ice and meltwater entered the North Atlantic during Heinrich stadial 1. This caused substantial regional cooling, but major climatic impacts also occurred in the tropics. Here, we demonstrate that the height of this stadial, about 16,000 to 17,000 years ago (Heinrich event 1), coincided with one of the most extreme and widespread megadroughts of the past 50,000 years or more in the Afro-Asian monsoon region, with potentially serious consequences for Paleolithic cultures. Late Quaternary tropical drying commonly is attributed to southward drift of the intertropical convergence zone, but the broad geographic range of the Heinrich event 1 megadrought suggests that severe, systemic weakening of Afro-Asian rainfall systems also occurred, probably in response to sea surface cooling.  相似文献   
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A certified organic apple (Malus × domestica Borkh.) orchard was established to study the interaction of ground cover management systems (GMS) and nutrient sources (NS) on nitrogen (N) use efficiency and N surplus in the Southern U.S. for three years. Trees treated with green compost (GC) and wood chips (WC), regardless of the NS, had greater N accumulation and leaf N use efficiency compared to the shredded paper or mow-and-blow treated trees. The WC-treated trees had comparably low N surplus relative to the GC trees that induced more [NO3] in soil or soil solution in the rooting zone in September in year 3. GC trees had the highest [NO3] mineralization in the soil during winter. GMS had greater overall effects on the tree response variables than did the NS.  相似文献   
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The zero points of charge (ZPC) of a natural bentonite and those of its homoionic forms (Na, Ca and Al) were determined by the transport number method. The influence of the interlayer cation was observed in the different pH values of the ZPC obtained. No influence of the water contains was observed.  相似文献   
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An 8-year-old, male castrated golden retriever presented for cough and increased respiratory effort. Radiographs revealed an alveolar pattern in the right caudal lung lobe and an opacity at the carina suspected to be enlarged tracheobronchial lymph nodes. The disease progressed to involve the right middle lung lobe. Cytopathology of a fine-needle aspirate and bronchoalveolar lavage fluid were nondiagnostic. Surgical removal of the right caudal lung lobe and biopsy of the perihilar lymph nodes revealed pulmonary thromboembolism and reactive lymph nodes. The dog died several days postoperatively, and necropsy revealed diffuse pulmonary thromboembolism. Additionally, Blastomyces dermatitis organisms were identified in a pyogranulomatous mass surrounding the trachea near the carina. In an extensive literature search, no reports of pulmonary thromboembolism associated with blastomycosis were identified. It is suspected that the inflammation secondary to blastomycosis caused the thromboembolism.  相似文献   
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Forest fire management practices are highly dependent on the proper monitoring of the spatial distribution of the natural and man-made fuel complexes at landscape level. Spatial patterns of fuel types as well as the three-dimensional structure and state of the vegetation are essential for the assessment and prediction of forest fire risk and fire behaviour. A combination of the two remote sensing systems, imaging spectrometry and light detection and ranging (LiDAR), is well suited to map fuel types and properties, especially within the complex wildland–urban interface. LiDAR observations sample the spatial information dimension providing explicit geometric information about the structure of the Earth's surface and super-imposed objects. Imaging spectrometry on the other hand samples the spectral dimension, which is sensitive for discrimination of surface types. As a non-parametric classifier support vector machines (SVM) are particularly well adapted to classify data of high dimensionality and from multiple sources as proposed in this work. The presented approach achieves an improved land cover mapping adapted to forest fire management needs. The map is based on a single SVM classifier combining the spectral and spatial information dimensions provided by imaging spectrometry and LiDAR.  相似文献   
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