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631.
Individual contribution of grain outer layers and their cell wall structure to the mechanical properties of wheat bran 总被引:1,自引:0,他引:1
Antoine C Peyron S Mabille F Lapierre C Bouchet B Abecassis J Rouau X 《Journal of agricultural and food chemistry》2003,51(7):2026-2033
The mechanical properties of wheat bran and the contribution of each constitutive tissue on overall bran properties were determined on a hard wheat (cv. Baroudeur) and a soft wheat (cv. Scipion). Manual dissection allowed three different layers to be separated from wheat bran, according to radial and longitudinal grain orientations, which were identified by confocal laser scanning microscopy as outer pericarp, an intermediate strip (comprising inner pericarp, testa, and nucellar tissue), and aleurone layer, respectively. Tissue microstructure and cell wall composition were determined. Submitted to traction tests, whole bran, intermediate, and aleurone layers demonstrated elastoplastic behavior, whereas pericarp exhibited elastic behavior. By longitudinal orientation, pericarp governed 50% bran elasticity (elastic strength and rigidity), whereas, in the opposite orientation, bran elastic properties were mostly influenced by the other tissues. Regardless of test orientation, the linear force required to bran rupture corresponded to the sum of intermediate and aleurone layer strengths. According to radial orientation, the intermediate strip governed bran extensibility, but according to longitudinal orientation, all tissues contributed until bran disruption. Tissues from both wheat cultivars behaved similarly. A structural model of wheat bran layers illustrated the detachment of pericarp from intermediate layer within radial bran strips. 相似文献
632.
Adult individuals of the parthenogenetic earthworm Octolasion tyrtaeum (Savigny 1826) differ considerably in body size. The length of adult specimens reaches 10–14 cm in some habitats, in others just 5–8 cm. In some habitats, individuals of both size classes coexist. Until now, size differences in O. tyrtaeum were ascribed to environmental rather than genetic factors. We used DNA-sequences of the mitochondrial gene for cytochrome oxidase II (COII) to measure genetic distances between O. tyrtaeum specimens of different size classes. Individuals of different geographical sites (including five sites in Germany and one site in Canada) were analysed. There was a strong correlation between the size of the earthworms and the COII sequences; large specimens separated clearly from small specimens. While sequences of large specimens were almost identical, those of small specimens were more diverse. This indicates that O. tyrtaeum consists of two morphologically and genetically different lineages. 相似文献
633.
Kristin J. Bentz Brandy A. Burgess Katharina L. Lohmann Farshid Shahriar 《The Canadian veterinary journal. La revue veterinaire canadienne》2009,50(3):283-286
A 4-year-old Belgian mare was presented with a 1-week history of fever, suspected of being caused by peritonitis. The mare died before the diagnostic procedures had been completed; postmortem examination revealed torsion of the left medial lobe of the liver, resulting in diffuse necrosis of liver tissue and severe peritoneal effusion. 相似文献
634.
635.
Diabetes Genetics Initiative of Broad Institute of Harvard MIT Lund University Novartis Institutes of BioMedical Research Saxena R Voight BF Lyssenko V Burtt NP de Bakker PI Chen H Roix JJ Kathiresan S Hirschhorn JN Daly MJ Hughes TE Groop L Altshuler D Almgren P Florez JC Meyer J Ardlie K Bengtsson Boström K Isomaa B Lettre G Lindblad U Lyon HN Melander O Newton-Cheh C Nilsson P Orho-Melander M Råstam L Speliotes EK Taskinen MR Tuomi T Guiducci C Berglund A Carlson J Gianniny L 《Science (New York, N.Y.)》2007,316(5829):1331-1336
New strategies for prevention and treatment of type 2 diabetes (T2D) require improved insight into disease etiology. We analyzed 386,731 common single-nucleotide polymorphisms (SNPs) in 1464 patients with T2D and 1467 matched controls, each characterized for measures of glucose metabolism, lipids, obesity, and blood pressure. With collaborators (FUSION and WTCCC/UKT2D), we identified and confirmed three loci associated with T2D-in a noncoding region near CDKN2A and CDKN2B, in an intron of IGF2BP2, and an intron of CDKAL1-and replicated associations near HHEX and in SLC30A8 found by a recent whole-genome association study. We identified and confirmed association of a SNP in an intron of glucokinase regulatory protein (GCKR) with serum triglycerides. The discovery of associated variants in unsuspected genes and outside coding regions illustrates the ability of genome-wide association studies to provide potentially important clues to the pathogenesis of common diseases. 相似文献
636.
Gabriel Perez Thibaud Decaëns Gaylord Dujardin Marthe Akpa-Vinceslas Estelle Langlois Matthieu Chauvat 《Pedobiologia》2013,56(4-6):169-177
It has been acknowledged that soil organisms play a significant role in nutrient cycling and thus may affect productivity and competition within plant assemblages with potential effects on vegetation trajectories. However, few studies have considered a single conceptual framework referring to both above–belowground linkages and plant succession. Consequently, we lack knowledge on the effects of plant successional processes on the dynamics of soil biota. Given this dearth of information, our study aimed to describe the dynamics of a major group of soil fauna, namely collembola, during the secondary succession on chalky slopes edging the Seine River. We selected five different plant assemblages as representative of a chronosequence: short grassland, tall grassland, encroached grassland, shrubland and forest. Our results clearly highlighted a strong response of collembolan assemblages to vegetation gradient. The changes in collembolan diversity were due to a high turnover rate in early successional stages and to nestedness in late successional stages. In addition, each collembolan life form had a specific response to vegetal succession. Euedaphic assemblages increased progressively during the succession while epedaphic did not follow a clear pattern. Our results also indicated a link between the dynamics of collembolan assemblages and plant life forms (e.g. trees and graminoids) rather than plant diversity. A focus on life forms, for plants and soil biota, seems to provide a good framework to study linkages between above and belowground biota. 相似文献
637.
DRIS-based fertilization efficiency of young hybrid poplar plantations in the boreal region of Canada 总被引:1,自引:0,他引:1
In order to maximize early growth and establishment of planted hybrid poplars in the boreal region of Eastern Canada, growth response of four clones to fertilization was tested in two plantations. The first two fertilization treatments were based on Diagnosis and Recommendation Integrated System (DRIS), a method based on nutrient ratios: DRIS I was based on previously established norms from a study that had been conducted in the same area, and DRIS II was based on DRIS norms developed from hybrid poplars in northern Ontario, Canada. Nutrient status and growth of trees under these 2 treatments were compared to unfertilized trees and to trees under standard (STD) fertilization treatment (40 N–20P–20 K). Leaf nutrient concentrations and DRIS indices showed that fertilization treatments, and especially DRIS I corrected N deficiencies but failed to correct P deficiencies. Fertilization increased volume relative growth rate by 7.51, 4.76 and 13.25 % on average at the agricultural site for DRIS I, DRIS II and STD treatments respectively, compared to no fertilizer application. At the forest site, fertilization treatments based on DRIS indices (DRIS I and DRIS II) increased growth rates (6.67 %) slightly more than the standard treatment (5.80 %). Overall, although DRIS-based fertilization treatments generally increased growth rates, they were often equal to or less efficient than the STD treatment, and may not be as practical as using a standard fertilization recipe. 相似文献
638.
J. P. Sampoux P. Baudouin B. Bayle V. Béguier P. Bourdon J. F. Chosson K. de Bruijn F. Deneufbourg C. Galbrun M. Ghesquière D. Noël B. Tharel A. Viguié 《Grass and Forage Science》2013,68(1):33-48
An assessment of genetic improvement in turf‐type perennial ryegrass was performed at a network of six locations. A comparison was made of the turf performances of five natural populations, five forage‐type cultivars used for turf seeding until the 1980s and 31 turf‐type cultivars released from 1974 to 2004. Populations and cultivars were also compared in two spaced‐plant experiments and in two seed‐yield trials. Trait regressions on registration year of turf‐type cultivars showed that breeding had been highly successful in improving the turf aesthetic merit (from +8·8 to +12·5% per decade according to seasons), wear tolerance (+5·4% per decade) and crown‐rust resistance (+8·9% per decade) and in lessening the turf height increase rate (?0·43 mm day?1 per decade). Turf winter greenness had been marginally improved, whereas summer greenness and seed yield had not been significantly changed. A multivariate analysis provided evidence that turf density and fineness played a major role in the visual assessment of turf aesthetic merit and that wear tolerance was closely associated with turf density. Conflicting trait associations may have precluded improvements in turf ground‐cover 3 months after sowing, turf winter greenness and turf persistency. 相似文献
639.
Eun Joo Shin Deepti Singh Soon Mo Choi Sun Mi Zo Yang Hun Lee Sung Soo Han 《Fibers and Polymers》2013,14(12):1965-1969
The present study reports the preparation of a cellulose scaffold for tissue engineering directly from cellulose fiber using ionic liquid (IL) by the NaCl leaching method with bovine serum albumin (BSA), which is well known protein utilized for biomedical applications like degradation of polymer, cell attachment and proliferation on scaffold. The 1-n-allyl-3-methylimidazolium chloride (AmimCl) IL was used as a solvent for cellulose. The morphology of the scaffold was studied by scanning electron microscopy (SEM) and the images showed that the pore sizes of the scaffolds were about 200 µm. In addition, the water uptake (WU) and degree of degradation of the cellulose scaffold were measured. Meanwhile, the biocompatibility and bioactivity of the scaffold were determined via 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenytetrazolium bromide (MTT) assay and the Live/Dead viability test. The various results demonstrated the ability of the Mesenchymal stem cells (MSC) to attach to the surface of the scaffolds amplified as percentage of BSA increased in cellulose scaffold. 相似文献
640.
This socio-economic study aims to better understand the functioning and the evolution of timber sales held by the French public forest service. The auction system is the historical institution which has been used for timber sales in France for centuries. The recent trend to develop supply contracts through private agreements has a major impact on the French timber industry, which is criticized for its lack of competitiveness. It accurately raises questions about the timber price issue. Indeed, the auction system plays an important role in price setting. We refer to the auction theory literature to examine the features of French timber auctions: first-price sealed-bid sequential auctions of heterogeneous standing timber lots. In particular, we note that seller's reserve price is kept secret and that, contrary to the general assumption in auction theory, the seller indubitably lacks information about his own reservation value. Finally, the difficulty of defining a “fair market price” remains a central issue in public timber sales. 相似文献