THE DUTY OF THE STATE IN THE PBOSECUTION OF MEDICAL RESEARCH     

Ward HB 《Science (New York, N.Y.)》1913,38(989):833-839

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CLIMATE AND CLIMATIC CHANGES IN KASHMIR     

Ward RD 《Science (New York, N.Y.)》1907,25(629):114-115

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CURRENT NOTES ON METEOROLOGY     

Ward RD 《Science (New York, N.Y.)》1904,19(490):801-802

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Lignin distribution across tracheid cell walls of poorly lignified wood from deformed copper deficient Pinus radiata (D. Don)     

G. M. Downes  J. V. Ward  N. D. Turvey 《Wood Science and Technology》1991,25(1):7-14

Summary Lignin topochemistry of tracheid walls from a deformed, copper deficient Pinus radiata (D. Don) tree was examined by linescan and point analyses using a Scanning Electron Microscope and Energy Dispersive Spectrometry. Both opposite and compression wood had abnormal lignin distributions compared to those observed in normal wood from a straight tree. Lignin contents in the compound middle lamella were lower than lignin contents in the secondary wall in both opposite and compression wood tracheids.One of us (G. D.) held a Commonwealth Forestry Postgraduate Research Award during this study. The research was supported in part by a grant from the Reserve Bank of Australia Rural Credits Development Fund, the Pine Fund, and members of the forest industry  相似文献   

Characteristic site disturbance due to harvesting and extraction machinery traffic on sensitive forest sites with peat soils   总被引：2，自引：0，他引：2  

Ciaran Nugent  Christopher Kanali  Philip M. O. Owende  Martin Nieuwenhuis  Shane Ward 《Forest Ecology and Management》2003,180(1-3):85-98

The effects of wood harvesting and extraction machinery traffic on sensitive forest sites with peat soils were characterised with the objective of quantifying the threshold levels beyond which significant site impacts (compaction and rutting) would occur. The treatments involved running the machines in selected extraction racks (i.e., 3 m wide machine routes) while conducting normal wood thinning and extraction operations comprising one and two passes by the harvester and the forwarder with full payload, respectively. Soil disturbance thresholds were established by testing the level of significance of the difference in induced soil damage and compaction before and after machine traffic treatments. For volumetric soil water content lying between 10.0 and 14.9%, threshold cone penetration resistance levels for two 600/55–30.5 tyres were found to range from 594 to 640 kPa for deep-raised peat soil with initial strength lying between 524 and 581 kPa. In general, the proportion of the total rut depth data in each rack that exceeded the threshold level of 21.5 cm was about 5%. The threshold value corresponds to sinkage equivalent to 15% of the overall wheel diameter of the harvester, above which machine mobility would be hampered considerably. In addition, after harvester traffic the mean rut depth per unit rack length was 10.2×10⁻² cm/m, and it ranged from 0.7 to 24.7×10⁻² cm/m.  相似文献   

Diversity and abundance of carabid beetles in short-rotation plantings of sweetgum, maize and switchgrass in Alabama   总被引：1，自引：0，他引：1  

K. E. Ward  R. N. Ward 《Agroforestry Systems》2001,53(3):261-267

This study compares assemblages of carabid beetles, potentially important regulators of herbivorous insect pests, in short-rotation plantings of sweetgum (Liquidambar styraciflua L.) with and without grass cover crops, maize (Zea mays L.) and switchgrass (Panicum virgatum L.). A total of 38 species were trapped during the summers of 1996 and 1997. The dominant carabid encountered was Harpalus pensylvanicus Latreille, a widespread omnivorous species; H. pensylvanicus was particularly prevalent in maize plots. Several other commonly encountered species were primarily associated with one plot type. Overall carabid activity was found to be similar in maize and switchgrass plots and much greater than that in sweetgum plots of both cover types. This may be related to the presence of more consistently available dense ground cover in these plots compared to sweetgum plots, a situation favored by most carabids, although both abundance and diversity were similar in sweetgum plots with and without cover. Diversity, as indicated by species richness and dominance levels, was greater in switchgrass than in maize or sweetgum plots, which were similar. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

Growth and enzyme production by Bacillus subtilis and Flavobacterium pectinovorum in Picea sitchensis     

William M. Fogarty  Owen P. Ward 《Wood Science and Technology》1973,7(4):261-270

Summary When Sitka spruce (Picea sitchensis) is stored in water, an increase takes place in the permeability of the wood. This increase is due to bacterial degradation of the tori and bordered pit membranes and partial degradation of the crossfield pits. It has been demonstrated that two bacteria—Bacillus subtilis and Flavobacterium pectinovorum—isolated from this water stored wood, grow and produce amylase, xylanase and pectinase in sapwood blocks suspended in sterile pond water. Since these organisms have also been shown to increase the permeability of sapwood blocks, it has been concluded that they are primarily responsible for the permeability changes that occur when spruce poles are stored in lake water.When the two organisms are incubated together in sapwood blocks, growth of F. pectinovorum is synergistically affected, while growth of B. subtilis is antagonised. However, no antagonism of enzyme production was evident. The levels of biological activity in the sapwood in these laboratory experiments were much higher than the values observed in the natural lake system. The concentration effect obtained in the laboratory system, in contrast to the dilution effect occurring in the lake environment, is undoubtedly responsible for this variance. Results indicate that the rate at which permeability changes occur could possibly be accelerated by replacing the natural lake system with an enclosed tank system.  相似文献   

Variation in infiltration with landscape position: Implications for forest productivity and surface water quality   总被引：1，自引：0，他引：1  

Thomas J. Sauer  Sally D. Logsdon  J. Van Brahana  John F. Murdoch 《Forest Ecology and Management》2005,220(1-3):118-127

Variation of infiltration rates with landscape position influences the amount, distribution, and routing of overland flow. Knowledge of runoff patterns gives land managers the opportunity to affect changes that optimize water use efficiency and reduce the risk of water quality impacts. The objective of this study was to assess the effect of landscape position and associated soil properties on infiltration in a small (147 ha) forest/pasture watershed in the Ozark Highlands. Three previously reported studies measured infiltration rates using double ring, sprinkling, single ring, and tension infiltrometers on soils at varying landscape positions. Although large variation in infiltration rates was observed among measurement techniques, upland and side slope soils (Nixa and Clarksville) had consistently lower infiltration rates compared to the soil in the valley bottom (Razort). A conceptual understanding of watershed runoff is developed from these data that includes infiltration excess runoff from the Nixa and Clarksville soils and saturation excess runoff on the Razort soil. Management of the soil water regime based on this understanding would focus on increasing infiltration in upland soils and maintaining the Razort soil areas in forest. Forest productivity would be enhanced by increasing plant-available water in upland soils and decreasing flooding on the Razort soil. Surface water quality would be improved by reducing the transport of potential water contaminants from animal manure applied to upland pastures.  相似文献   

GEOVET 2013: Geospatial analysis in veterinary epidemiology and preventive medicine     

Michael P. Ward 《Preventive veterinary medicine》2014

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The effects of kin and familiarity on interactions between fish   总被引：8，自引：0，他引：8  

Ashley J W Ward  & Paul J B Hart 《Fish and Fisheries》2003,4(4):348-358

Fish have been shown to discriminate between individuals on very general bases such as species, body length and colour. More recently, evidence has been accumulating from a number of species that relatedness and familiarity may be extremely important in mediating a range of interactions between individual fish. Studies have shown that fish are able to recognize kin and/or familiars, and that this ability potentially conveys significant benefits, including increased inclusive fitness, reduced inbreeding costs, reduced competition and enhanced antipredator behaviour. Here, we review the literature and consider future directions and applications for this research.  相似文献