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61.
Tonya A. Lander Etienne K. Klein Solenn Stoeckel Stéphanie Mariette Brigitte Musch Sylvie Oddou-Muratorio 《Landscape Ecology》2013,28(9):1769-1783
Widespread ecosystem change has led to declines in species world-wide. The loss of pollinators in particular constitutes a problem for ecosystem function and crop production. Understanding how landscape change affects pollinator movement, effective pollen flow, and plant and pollinator survival is therefore a global priority. In this study we investigated patterns of effective pollen flow, using wild cherry tree (Prunus avium) progeny arrays, to address two questions in three case studies: Do land-use types present different resistances to pollinator movement? Which pollinator travel path best explains the pollination data (straight lines, weighted straight lines, least cost paths or pair-wise resistance)? Trees and progeny arrays were genotyped and effective pollen flow and pollinator movement were estimated using the spatially explicit mating model. We found that pollinators did modify their travel paths in response to land-use type and arrangement, but the travel path that best described pollinator movement and the resistance rank of the land uses depended on the type and size of land-use patches and the landscape context. We propose a novel theoretical framework rooted in behavioural ecology, the resource model, for interpreting pollinator behaviour in heterogeneous landscapes. We conclude by discussing the importance and practicality of conservation and management strategies in which native and non-native land-use types together provide functional habitat and support ecosystem services across economic landscapes. 相似文献
62.
Geert J. W. Janssen Arend Van Norel Brigitte Verkerk-Bakker Richard Janssen 《Potato Research》1995,38(4):353-362
Summary Various methods of screening for resistance to root-knot nematodes were compared and evaluated. Seedling populations ofSolanum spp., grown in clay pots and plastic tubes with silver sand and inoculated with juveniles ofMeloidogyne chitwoodi andM. hapla, showed large differences in the number of egg masses on roots 7 weeks after inoculation. The differences were reproducible
when re-testing was done with cuttings and plants from tubers. No resistance toMeloidogyne spp. was observed with ten potato cultivars when grown in clay pots, plastic tobes or closed containers. Plants from tubers
in growth pouches developed a large two-dimensional root system, and after inoculation with juveniles the infection process
could be observed over 8 weeks.
A method of infecting potato tuber tissue withMeloidogyne is described, using tuber slices in Petri dishes as a potential screening test for tuber resistance. 相似文献
63.
64.
Ameet Singh DVM DVSc Diplomate ACVS Brigitte A. Brisson DMV DVSc Diplomate ACVS Stephanie Nykamp DVM Diplomate ACVR 《Veterinary surgery : VS》2011,40(6):762-767
Objective: To (1) describe computed tomographic (CT) popliteal lymphangiography; (2) compare the number of thoracic duct (TD) branches detected by CT and by radiography after popliteal lymphangiography; and (3) to compare the number of branches detected after left and right popliteal lymphangiography. Study Design: Experimental study. Animals: Adult dogs (n=6). Methods: A randomly selected popliteal lymph node was percutaneously injected with 12 mL iodinated contrast medium through a 25‐g butterfly catheter over 4–5 minutes. Lateral and ventrodorsal (VD) thoracic radiograph projections and thoracic CT were performed. The procedure was repeated using the contralateral lymph node after a 48–72 hours washout period. Results: One dog had TD branches visible on CT but not on radiographs. A significantly greater number of TD branches were observed with CT popliteal lymphangiography compared with lateral and VD radiographic popliteal lymphangiography (P=.003 and P<.001, respectively). The number of visible TD branches observed between the 6th thoracic and 1st lumbar vertebrae were not significantly different in these dogs (P=.146). A significant difference in number of TD branches observed was not found after left or right popliteal lymph node injection (P=.097). Conclusions: CT popliteal lymphangiography consistently identified a greater number of TD branches when compared with radiographic popliteal lymphangiography. Injection of either popliteal lymph node resulted in the same number of TD branches being observed. 相似文献
65.
Brigitte Moreau J Christophe Vié Philippe Cotellon Ingrund De Thoisy Annie Motard Christian P Raccurt 《Journal of zoo and wildlife medicine》2003,34(2):159-162
Individuals of two porcupine species (Coendou prehensilis and Coendou melanurus) were translocated during the flooding of a forest at a hydroelectric dam site in French Guiana. Blood samples were collected for 11 mo to determine hematologic and serum chemistry reference mean values and ranges and to look for blood parasites. Male C. prehensilis had significantly higher hemoglobin levels, packed cell volumes, and creatinine and potassium values than did females of the same species. Coendou prehensilis had significantly lower amylase levels but higher creatinine, calcium, lactate dehydrogenase, and gamma glutamyl transferase levels than C. melanurus. 相似文献
66.
Evaluation of a method to assess digitally recorded surgical skills of novice veterinary students
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67.
Growth, mycorrhiza and frost resistance of Picea abies seedlings following fertilization with different levels of nitrogen . NPK fertilization with varying levels of nitrogen causes increased growth of spruce seedlings and faster flushing in spring. During the growing season, the frost resistance of all organs of the plants, especially new needles and shoots is the lower, the more nitrogen the plants have received. Consequently, spruce plantations, especially at high altitudes, may be liable to late frost damage. 相似文献
68.
Thierry Koumbi-Mounanga Tony Ung Paul Cooper Brigitte Leblon Kevin Groves 《Wood material science & engineering》2015,10(1):17-26
AbstractThe potential of near infrared spectroscopy (NIRS) to estimate wood moisture content (MC), surface energy characteristics and adhesive bond strength were evaluated on aspen (Populus tremuloides Michx.) veneer subjected to different drying times. For samples dried progressively at 103°C, the best MC prediction model was for the total MC range (0–100%) with an R2 value of 0.68. However, exposure at 180°C produced surface colour changes, and the CIE L*a*b* colour parameters measuring colour changes were better estimated using the 400–900 nm spectral data than the 1100–2400 nm spectral data. Increased exposure time at 180°C resulted in lower wettability and, hence, larger contact angles, especially when ethylene glycol was used as probe solvent. Lap shear strength tests on veneers showed that adhesion by phenol formaldehyde resins was impaired by the high temperature exposure; however, the lap shear strength test had high variability so there was not always a clear relationship between contact angle and lap shear strength test. 相似文献
69.
Imamura K Yasuda M Riwar B Inui S Ekino S 《Comparative immunology, microbiology and infectious diseases》2009,32(5):419-428
We established the method of isolating individually encapsulated germinal centers (GCs) from immunized spleen and analyzed single cell suspension of GCs by flowcytometry. In GCs, the high frequency of sIgG+ cells (29%) and sIgA+ cells (5%) was detected. Two-color flowcytometry analysis showed that GCs contained 27% of sIgM-IgG+ cells, in which isotype switch from IgM to IgG had occurred, and 5% of Bu1-IgG+ cells, which were differentiating into plasma cells. On the other hand, sIgM-IgG+ and Bu1-IgG+ cells were not detected in the bursa, which contained 95% of B cells and only 1% of T cells. CD4+ but not CD8+ T cells were detected in the light zone of GCs and these CD4+ T cells are supposed to play a key role in isotype switching and differentiation into plasma cells in GCs. These results clearly demonstrate that GCs provide a site for isotype switching and differentiation into plasma cells. 相似文献
70.
Martin S. A. Seewald Wolfgang Singer Brigitte A. Knapp Ingrid H. Franke-Whittle Armin Hansel Heribert Insam 《Biology and Fertility of Soils》2010,46(4):371-382
The agronomic effects of composts, mineral fertiliser and combinations thereof on chemical, biological and physiological soil
properties have been studied in an 18-year field experiment. The present study aimed at tracing treatment effects by evaluating
the volatile organic compound (VOC) emission of the differently treated soils: non-amended control, nitrogen fertilisation
and composts (produced from organic waste and sewage sludge, respectively) in combination with nitrogen fertiliser. Microbial
community structure was determined by denaturing gradient gel electrophoresis (DGGE). Aerobic and anaerobic soil VOC emission
was determined after glucose amendment using proton transfer reaction–mass spectrometry (PTR-MS). After inducing VOC production
by substrate (glucose) addition and at the same time reducing oxygen availability to impair degradation of the produced VOCs,
we were able to differentiate among the treatments. Organic waste compost did not alter the VOC emissions compared to the
untreated control, whilst sewage sludge composts and mineral fertilisation showed distinct effects. This differentiation was
supported by DGGE analysis of fungal 18S rDNA fragments and confirms earlier findings on bacterial communities. Three major
conclusions can be drawn: (1) VOC patterns are able to discriminate among soil treatments. (2) Sewage sludge compost and mineral
fertilisation have not only the strongest impact on microbial community composition but also on VOC emission patterns, but
specific tracer VOCs could not be identified. (3) Future efforts should aim at a PTR-MS-linked identification of the detected
masses. 相似文献