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11.
世界粮食研究模型在黑龙江省作物产量预报中的应用 总被引:6,自引:5,他引:6
在现有研究成果的基础上,提出世界粮食研究(WOFOST)模型在黑龙江省四大作物产量预报应用中的参数分区处理方法,运用WOFOST的模拟产量和趋势产量对黑龙江省四大作物产量进行了预测分析。研究表明:该方法效果理想、可行,具有理论研究和实际应用价值,克服了只用一组参数在复杂气候区域进行作物产量模拟的局限性,拓宽了WOFOST模型在复杂气候条件下的应用领域。 相似文献
12.
Yannick D.N. Tremblay Skander Hathroubi Mario Jacques 《Canadian journal of veterinary research》2014,78(2):110-116
Bacterial biofilms are structured communities of bacterial cells enclosed in a self-produced polymer matrix that is attached to a surface. Biofilms protect and allow bacteria to survive and thrive in hostile environments. Bacteria within biofilms can withstand host immune responses, and are much less susceptible to antibiotics and disinfectants when compared to their planktonic counterparts. The ability to form biofilms is now considered an attribute of many microorganisms. Diseases associated with biofilms require novel methods for their prevention, diagnosis and treatment; this is largely due to the properties of biofilms. Furthermore, the presence of biofilms on surfaces found at farms, slaughterhouses or food processing plants will have an impact on the efficacy of disinfection protocols. Surprisingly, biofilm formation by bacterial pathogens of veterinary or zoonotic importance has received relatively little attention. The objective of this brief Review article is to bring awareness about the importance of biofilms to animal health stakeholders.(Translated by the authors) 相似文献
13.
This study investigates the impact of landscape heterogeneity on community structure and population dynamics in two families of Diptera (Empididae and Chironomidae). Adult emergence is compared with aerial flow by means of emergence traps and yellow traps on a transect across four habitats (pond banks, woodland, grassland and heathland) in close proximity to each other. Empids use different space units according to their larval development, sexual behaviour and food requirements. This creates an intermingling of species and individuals originating from different habitats in the lowest part of the transect. Adult chironomids of aquatic species exhibit a preferential use of open habitats while adults with terrestrial larvae disperse largely above the four sites. Habitat fragmentation and heterogeneity lead to opposite patterns in chironomid distribution: some species disperse over the whole set of macrohabitats but others are confined to a single patch, resulting in population isolation. The impact of spatial and temporal landscape patterning is discussed with a view to community structure, life-history tactics and population dynamics. 相似文献
14.
Jacques M Aragon V Tremblay YD 《Animal health research reviews / Conference of Research Workers in Animal Diseases》2010,11(2):97-121
Bacterial biofilms are structured communities of bacterial cells enclosed in a self-produced polymer matrix that is attached to a surface. Biofilms protect and allow bacteria to survive and thrive in hostile environments. Bacteria within biofilms can withstand host immune responses, and are much less susceptible to antibiotics and disinfectants when compared with their planktonic counterparts. The ability to form biofilms is now considered a universal attribute of micro-organisms. Diseases associated with biofilms require novel methods for their prevention, diagnosis and treatment; this is largely due to the properties of biofilms. Surprisingly, biofilm formation by bacterial pathogens of veterinary importance has received relatively little attention. Here, we review the current knowledge of bacterial biofilms as well as studies performed on animal pathogens. 相似文献
15.
Yannick Joye Kim Willems Malaika Brengman Kathleen Wolf 《Urban Forestry & Urban Greening》2010,9(1):57-64
Over the last three decades solid empirical evidence for the positive influence of greenery on human psychological and cognitive functioning has been steadily accruing. Based on this evidence, researchers and practitioners increasingly realize the importance of urban greening as a strategic activity to promote human wellbeing. Although commercial and retail activities constitute a significant and influential component of urban contexts, a concern is that the stakeholders involved (e.g. merchants) can sometimes be reluctant to integrate vegetation in commercial districts. This can be an important stumbling block for the process of urban greening. In this paper we introduce the concept of Biophilic Store Design (BSD) as the retail design strategy to consciously tap the beneficial effects of vegetation. The central aim of this paper is to demonstrate that the reluctance of certain retail stakeholders to integrate greening practices like BSD is unjustified. Two lines of evidence in support of this claim will be discussed. On the one hand, we sketch a conceptual framework which supports the view that BSD can have restorative effects for those implied in store environments. On the other hand, we review Wolf's multi-study research program on the effects of urban greening on consumer behavior, attitudes, and perceptions. These two lines of evidence show that commercial activities and urban greening are not to be considered as antagonistic but as mutually reinforcing practices. 相似文献
16.
Evelyne Picard‐Meyer Veronique Beven Edouard Hirchaud Cdric Guillaume Grald Larcher Emmanuelle Robardet Alexandre Servat Yannick Blanchard Florence Cliquet 《Zoonoses and public health》2019,66(2):254-258
Bat rabies cases are attributed in Europe to five different Lyssavirus species of 16 recognized Lyssavirus species causing rabies. One of the most genetically divergent Lyssavirus spp. has been detected in a dead Miniopterus schreibersii bat in France. Brain samples were found positive for the presence of antigen, infectious virus and viral RNA by classical virological methods and molecular methods respectively. The complete genome sequence was determined by next‐generation sequencing. The analysis of the complete genome sequence confirmed the presence of Lleida bat lyssavirus (LLEBV) in bats in France with 99.7% of nucleotide identity with the Spanish LLEBV strain (KY006983). 相似文献
17.
Salmon D Vanwalleghem G Morias Y Denoeud J Krumbholz C Lhommé F Bachmaier S Kador M Gossmann J Dias FB De Muylder G Uzureau P Magez S Moser M De Baetselier P Van Den Abbeele J Beschin A Boshart M Pays E 《Science (New York, N.Y.)》2012,337(6093):463-466
The parasite Trypanosoma brucei possesses a large family of transmembrane receptor-like adenylate cyclases. Activation of these enzymes requires the dimerization of the catalytic domain and typically occurs under stress. Using a dominant-negative strategy, we found that reducing adenylate cyclase activity by about 50% allowed trypanosome growth but reduced the parasite's ability to control the early innate immune defense of the host. Specifically, activation of trypanosome adenylate cyclase resulting from parasite phagocytosis by liver myeloid cells inhibited the synthesis of the trypanosome-controlling cytokine tumor necrosis factor-α through activation of protein kinase A in these cells. Thus, adenylate cyclase activity of lyzed trypanosomes favors early host colonization by live parasites. The role of adenylate cyclases at the host-parasite interface could explain the expansion and polymorphism of this gene family. 相似文献
18.
19.
Effects of agricultural practices on hydraulic properties and water movement in soils in Brittany (France) 总被引:2,自引:0,他引:2
Babacar Ndiaye Jrme Molnat Vincent Hallaire Chantal Gascuel Yannick Hamon 《Soil & Tillage Research》2007,93(2):251-263
The intensive agricultural use of soils in the Brittany region (western France) has increased the need for a better understanding of soil water dynamics. The aim of the present study is to compare quantitatively the differences produced by two agricultural practices on soil hydraulic properties (water retention curve and hydraulic conductivity) as well as the infiltration and drainage fluxes in the soils. This study was carried out on two experimental plots managed in the same way for 22 years. The two practices were continuous maize fertilized with mineral fertilizer, denoted as MX, and pasture within a ray-grass/maize rotation (3/1 year) with organic fertilization (pig slurry), denoted as PR. The study consisted of measuring soil physical properties in the laboratory and in the field, and estimating water infiltration in the soil of the two plots by recording water pressure heads after simulation of 2-h artificial rainfall with an intensity of 17 mm/h. We applied the van Genuchten model to describe the water retention and hydraulic conductivity curves (θ(h) and K(h)) for each soil horizon of the two plots. Hydrus-2D and ID softwares were used to construct a numerical model of water movement in the two soils. This model was used to quantify the infiltration rate, deep drainage and actual evaporation fluxes during the artificial rainfall experiment.The vertical influence of agricultural practices in both plots appears to be limited to the uppermost 35 cm. Deeper in the B horizon, there are only very slight differences in the hydraulic properties between the two plots. In the top soil horizons (H1–H5 and H6), the two soil properties mostly affected by practices are the hydraulic conductivity and the α parameter of the van Genuchten model. At the lowest pressure head studied here (−1.5 kPa), hydraulic conductivity in a given horizon differs by more than one order of magnitude between the two plots. The model reproduces quite satisfactorily the observed pressure heads in plot PR at all depths, in the rainy period as well as in the water redistribution period (efficiency >0.77). Results are less good for the MX plot, with efficiency ranging from 0.49 to 0.84 depending on the horizon. The different sources of simulation errors are identified and discussed. For the MX plot, the soil water movement model succeeds in reproducing the infiltration excess runoff observed in the field, allowing us to calculate that it accounts for 9% of the applied rainfall. No surface runoff or ponding appears in the PR plot during the artificial rainfall experiment. In the PR plot, the simulated deep drainage flux increases more rapidly than in the MX plot. The lower hydraulic conductivity in the top soil horizon of the MX plot compared with the PR plot appears to reduce the infiltration rate as well as the deep drainage flux. It also decreases the upward flow of water to the soil surface when the water content in the top soil layer is depleted by evaporation flux. The model simulation could be improved by a more precise representation of the soil structure, particularly the location, size and frequency of clods as well as the variability of hydraulic properties. However, we need to strike a balance between improving the quality of the simulation even further and the practical constraints and efforts involved in measuring the soil hydraulic properties. 相似文献