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121.
A. R. Graves P. J. Burgess F. Liagre J.-P. Terreaux T. Borrel C. Dupraz J. Palma F. Herzog 《Agroforestry Systems》2011,81(2):93-108
Financial feasibility and financial return are two key issues that farmers and land owners consider when deciding between
alternative land uses such as arable farming, forestry and agroforestry. Moreover regional variations in yields, prices and
government grants mean that the relative revenue and cost of such systems can vary substantially within Europe. To aid our
understanding of these variations, the European Commission sponsored a research project called “Silvoarable Agroforestry For
Europe” (SAFE). This paper describes the process of developing a new economic model within that project. The initial stages
included establishing criteria for the model with end-users and reviewing the literature and existing models. This indicated
that the economic model needed to allow comparison of arable farming, forestry and agroforestry systems at a plot- and a farm-scale.
The form of comparisons included net margins, net present values, infinite net present values, equivalent annual values, and
labour requirements. It was decided that the model would operate in a spreadsheet format, and the effect of phased planting
patterns would be included at a farm-scale. Following initial development, additional user feedback led to a final choice
on a model name, a final method of collating input data, and the inclusion of field-based operations such as varying the cropped
area, replacing dead trees, and pruning. In addition options in terms of improved graphical outputs and the ability to undertake
sensitivity analysis were developed. Some of the key lessons learnt include the need to establish clear model criteria and
the benefits of developing a working prototype at an early stage to gain user-feedback. 相似文献
122.
E W Merrill D J Graves K A Smith D C Shannon H Kazemi 《Science (New York, N.Y.)》1969,164(884):1167-1168
Dl-Dipalmitoyl-alpha-lecithin, suspended in 0.15-molar sodium chloride solution by sonic cavitation at 20 kilohertz, can be aerosolized by an 800-kilohertz ultrasonic generator only at temperatures above 25 degrees C. The aerosol thus produced is exceptionally stable against evaporation even at particle radii of 0.1 to 0.6 micron; this suggests applicability to the therapy of pulmonary disorders. 相似文献
123.
Giasson BI Forman MS Higuchi M Golbe LI Graves CL Kotzbauer PT Trojanowski JQ Lee VM 《Science (New York, N.Y.)》2003,300(5619):636-640
Alpha-synuclein (alpha-syn) and tau polymerize into amyloid fibrils and form intraneuronal filamentous inclusions characteristic of neurodegenerative diseases. We demonstrate that alpha-syn induces fibrillization of tau and that coincubation of tau and alpha-syn synergistically promotes fibrillization of both proteins. The in vivo relevance of these findings is grounded in the co-occurrence of alpha-syn and tau filamentous amyloid inclusions in humans, in single transgenic mice that express A53T human alpha-syn in neurons, and in oligodendrocytes of bigenic mice that express wild-type human alpha-syn plus P301L mutant tau. This suggests that interactions between alpha-syn and tau can promote their fibrillization and drive the formation of pathological inclusions in human neurodegenerative diseases. 相似文献
124.
Thirty spring wheat varieties were evaluated and classified into eight different groups on the basis of their grain yield performance and phosphorus (P) uptake using Metroglyph analysis. Significant variability was observed for grain and biomass yield, plant height, P content in grain and straw, total P uptake and phosphorus harvest index and P use efficiency traits. Varieties WH 711 and PBW 343 exhibited high grain yield as well as high P uptake (HGY-HP). WH 283 and UP 2425 with high index score of 19 and 16 respectively, constituted the high grain yield-medium P uptake (HGYMP) group. Both these varieties, though had similar grain yield of 5348 kg/ha, but WH 283 (12.64 kg/ha) utilized much lower P as compared to UP 2425 (16.94 kg/ha). Moreover, WH 283 (81.64) also showed higher values for phosphorus harvest index (PHI) than UP 2425 (67.88%). P uptake of WH 283 was comparable with that of Raj 3765 (10.78 kg/ha) and grouped into high grain yield and low P uptake (HGY-LP) group. The grain yield performance of these two varieties with a relatively low P uptake is reflected in their high index score for P use efficiency thus, earmarking them for low P regimes. Variety HW 2006, despite low grain yields of 4665 kg/ha had high index score of 16 due to its higher value for Phosphorus Biological (PBER) and Economic Yield (PEER) Efficiency Ratio as it has effected least (7.18 kg/ha) P mobilization. In addition high P translocation in the grain was also observed for this variety. Inter-mating of genotypes like HW 2006, UP 2338 and HW 2016 with those belonging to HGY-HP (PBW 343 and WH 711) and HGY-LP (Raj 3765 and WH 283) would be an ideal strategy to develop the cultivars for efficient phosphorus use. 相似文献
125.
- The ecology of endangered and rare species can be difficult to study owing to their low abundances and legal limits on scientist’s ability to catch, sample, and track them. This is particularly true of sawfish (family Pristidae), whose numbers have declined precipitously, placing all five species on the IUCN Red List of Threatened Species worldwide. Best known for their distinctive, toothed rostrum, the ecology, movement and life-history of sawfish are poorly understood.
- Sawfish rostral teeth are modified placoid scales, which grow continuously throughout the life of the fish. This continuous growth, combined with their stable calcified makeup, makes sawfish rostral teeth a potential source of temporal records of chemical and isotopic changes through the life of the fish.
- Rostral teeth are often preserved in museums and as curios, potentially providing a source of life-history data to inform conservation actions without the need for field study, or as an important compliment to it. This is the first study to recover temporally explicit chemical data from sawfish rostral teeth.
- Using archived samples of largetooth sawfish (Pristis pristis) we show that multiple chemical tracers can be recovered from sawfish rostral teeth, and that these tracers can be used to understand movement across salinity gradients. We further show that sawfish rostral teeth contain repeated structures and indistinct banding which could potentially be used for ageing or growth analysis of fish.
126.
C. Gilor S. Gilor T.K. Graves L.B. Borst P. Labelle T.K. Ridge D. Santoro O. Dossin 《Domestic animal endocrinology》2013
Glucose-dependent insulinotropic peptide (GIP), glucagon-like peptide (GLP)-1 and GLP-2 are hormones secreted from specialized K cells (GIP) and L cells (GLP-1, GLP-2) in the intestinal mucosa. These hormones play major roles in health and disease by modulating insulin secretion, satiety, and multiple intestinal functions. The aim of this study was to describe the distribution of K cells and L cells in the intestines of healthy cats. Samples of duodenum, mid-jejunum, ileum, cecum, and colon were collected from 5 cats that were euthanized for reasons unrelated to this study and had no gross or histologic evidence of gastrointestinal disease. Samples stained with rabbit-anti-porcine GIP, mouse-anti-(all mammals) GLP-1, or rabbit-anti-(all mammals) GLP-2 antibodies were used to determine the number of cells in 15 randomly selected 400× microscopic fields. In contrast to other mammals (eg, dogs) in which K cells are not present in the ileum and aborally, GIP-expressing cells are abundant throughout the intestines in cats (>6/high-power field in the ileum). Cells expressing GLP-1 or GLP-2 were most abundant in the ileum (>9/high-power field) as in other mammals, but, although GLP-1–expressing cells were abundant throughout the intestines, GLP-2–expressing cells were rarely found in the duodenum. In conclusion, the distribution of GIP-secreting K cells in cats is different from the distribution of K cells that is described in other mammals. The difference in distribution of GLP-2– and GLP-1–expressing cells suggests that more than 1 distinct population of L cells is present in cats. 相似文献
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