Radiation-use efficiency of a forest exposed to elevated concentrations of atmospheric carbon dioxide     

DeLucia EH  George K  Hamilton JG 《Tree physiology》2002,22(14):1003-1010

We compared radiation-use efficiency of growth (epsilon;), defined as rate of biomass accumulation per unit of absorbed photosynthetically active radiation, of forest plots exposed to ambient (approximately 360 micro l l-1) or elevated (approximately 560 micro l l-1) atmospheric CO2 concentration ([CO2]). Large plots (30-m diameter) in a loblolly pine (Pinus taeda L.) plantation, which contained several hardwood species in the understory, were fumigated with a free-air CO2 enrichment system. Biomass accumulation of the dominant loblolly pines was calculated from monthly measurements of tree growth and site-specific allometric equations. Depending on the species, leaf area index (L*) was estimated by three methods: optical, allometric and litterfall. Based on the relationship between tree height and diameter during the first 3 years of exposure, we conclude that elevated [CO2] did not alter the pattern of aboveground biomass allocation in loblolly pine. There was considerable variation in L* estimates by the different methods; total L* was 18-42% lower when estimated by the optical method compared with estimates from allometric calculations, and this discrepancy was reduced when optical measurements were corrected for the non-random distribution of loblolly pine foliage. The allometric + litterfall approach revealed a seasonal maximum total L* of 6.2-7.1 with about 1/3 of the total from hardwood foliage. Elevated [CO2] had only a slight effect on L* in the first 3 years of this study. Mean epsilon; (+/- SD), calculated for loblolly pine only, was 0.49 +/- 0.05 and 0.62 +/- 0.04 g MJ-1 for trees in the ambient and elevated [CO2] plots, respectively. The 27% increase in epsilon; in response to CO2 enrichment was caused primarily by the stimulation of biomass increment, as there was only a small effect of elevated [CO2] on L* during the initial years of fumigation. Long-term increases in atmospheric [CO2] can increase epsilon; in closed-canopy forests but the absolute magnitude and duration of this increase remain uncertain.  相似文献   

Investigation of biosecurity risks associated with the feed delivery: A pilot study     

Kate Bottoms  Cate Dewey  Karen Richardson  Zvonimir Poljak 《The Canadian veterinary journal. La revue veterinaire canadienne》2015,56(5):502-508

This study explored potential biosecurity issues related to the delivery of feed to commercial farms. A pilot study was conducted to collect information about the day-to-day feed delivery, including biosecurity concerns at the level of the feed truck, the driver, and the farm. In addition, a reusable rubber boot was tested in an effort to increase the proportion of farms at which truck drivers wore clean footwear, and to explore an alternative to the standard plastic disposable boots that may be unsafe in winter conditions. Most farms did well in terms of proper dead-stock management and keeping the farm lane and feed bin areas clean. The provision of reusable rubber boots significantly increased the proportion of deliveries in which the driver wore clean footwear.  相似文献   

Metatranscriptomics reveals metabolic adaptation and induction of virulence factors by Haemophilus parasuis during lung infection     

Bernardo Bello-Ortí  Kate J. Howell  Alexander W. Tucker  Duncan J. Maskell  Virginia Aragon 《Veterinary research》2015,46(1)

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Sampling plan and test protocol for the semiquantitative detection of genetically modified canola (Brassica napus) seed in bulk canola seed   总被引：1，自引：0，他引：1  

Emslie KR  Whaites L  Griffiths KR  Murby EJ 《Journal of agricultural and food chemistry》2007,55(11):4414-4421

Using a statistical approach, sampling plans for the semiquantitative detection of genetically modified (GM) canola within a bulk seed sample can be developed and tailored to meet different GM thresholds, costs, and confidence limits. This is achieved by changing the number of subsamples analyzed, the number of seeds per subsample, and the percentage of positive results allowed. These sampling plans must be devised carefully, taking into account the detection capability of the analytical assay. This is particularly important in the case of InVigor (a registered trademark of Bayer CropScience) canola, for which expression levels of the introduced protein in seed are very low. Lateral flow assays and enzyme-linked immunosorbent assays (ELISA) were both investigated for their suitability as a qualitative assay using a subsampling approach. On the basis of an ELISA, several sampling plans have been devised and validated to provide at least 99% confidence that bulk seed samples containing at least 0.9% (w/w) InVigor canola will be detected. Although the term "seed" is used throughout this paper to refer to the canola, the term "seed" is to be taken to include both seed and the canola seed (grain) that is harvested by the farmer/grower.  相似文献   

Evaluation of harmful algal bloom outreach activities          下载免费PDF全文

Fleming LE  Jerez E  Stephan WB  Cassedy A  Bean JA  Reich A  Kirkpatrick B  Backer L  Nierenberg K  Watkins S  Hollenbeck J  Weisman R 《Marine drugs》2007,5(4):208-219

With an apparent increase of harmful algal blooms (HABs) worldwide, healthcare providers, public health personnel and coastal managers are struggling to provide scientifically-based appropriately-targeted HAB outreach and education. Since 1998, the Florida Poison Information Center-Miami, with its 24 hour/365 day/year free Aquatic Toxins Hotline (1–888–232–8635) available in several languages, has received over 25,000 HAB-related calls. As part of HAB surveillance, all possible cases of HAB-related illness among callers are reported to the Florida Health Department. This pilot study evaluated an automated call processing menu system that allows callers to access bilingual HAB information, and to speak directly with a trained Poison Information Specialist. The majority (68%) of callers reported satisfaction with the information, and many provided specific suggestions for improvement. This pilot study, the first known evaluation of use and satisfaction with HAB educational outreach materials, demonstrated that the automated system provided useful HAB-related information for the majority of callers, and decreased the routine informational call workload for the Poison Information Specialists, allowing them to focus on callers needing immediate assistance and their healthcare providers. These results will lead to improvement of this valuable HAB outreach, education and surveillance tool. Formal evaluation is recommended for future HAB outreach and educational materials.  相似文献   

Diagnostic Ophthalmology     

Lynne S. Sandmeyer  Bianca S. Bauer  Kate Robinson  Bruce H. Grahn 《The Canadian veterinary journal. La revue veterinaire canadienne》2014,55(3):281-283

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Effects of salinity and temperature during incubation on hatching and development of lingcod Ophiodon elongatus Girard, embryos     

Matthew A Cook  Kate M Guthrie  Michael B Rust  & Paul D Plesha 《Aquaculture Research》2005,36(13):1298-1303

The interactive effects of salinity and temperature on development and hatching success of lingcod, Ophiodon elongatus Girard, were studied by incubating eggs at four temperatures (6, 9, 12 and 15°C) and five salinities (15, 20, 25, 30 and 35 g L^?1). Hatch did not occur in any of the 15°C treatments. Degree days (°C days) to first hatch was not influenced by temperature or salinity, however, calendar days to first hatch differed significantly for temperature (P<0.0001, 61±1, 44±1 and 35±1 days for 6, 9 and 12°C respectively). Degree days to 50% (427.1±4.2) hatch was not significantly influenced by temperature but was by salinity (P=0.0324). Viable hatch (live with no deformities, 74.1±4.0%) was greatest at 9°C and 25 g L^?1 but not significantly different in the range of 20–30 g L^?1. Larval length (9.4±0.13 mm) was greatest at 9°C and 20–30 g L^?1. Temperature and salinity significantly influenced all categories of deformities with treatments at the upper (12°C and 35 g L^?1) and lower limits (6°C and 15 g L^?1) producing the greatest deformities. The optimal temperature and salinity for incubating Puget Sound lingcod eggs was found to be 9°C and 20–30 g L^?1.  相似文献   

A comparison of Japanese and Australian consumers’ sensory perceptions of beef     

Rod J. Polkinghorne  Takanori Nishimura  Kate E. Neath  Ray Watson 《Animal Science Journal》2014,85(1):69-74

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Acid base,electrolyte, glucose,and lactate values during cardiopulmonary resuscitation in dogs and cats     

Kate Hopper BVSc  PhD  DACVECC  Angela Borchers DVM  DACVIM  DACVECC  Steven E. Epstein DVM  DACVECC 《Journal of Veterinary Emergency and Critical Care》2014,24(2):208-214

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Taxonomic and functional macroinvertebrate diversity of high-altitude ponds in the Macun Cirque,Switzerland     

Matthew J. Hill  Paul J. Wood  Kate L. Mathers 《水产资源保护:海洋与淡水生态系统》2021,31(11):3201-3214

1. Global environmental change is threatening freshwater biodiversity with ecological impacts predicted to be particularly severe in high-altitude regions. Despite this, an ecological understanding of high-altitude pond networks remains patchy, with only limited knowledge of the environmental and spatial predictors of taxonomic and functional diversity. Moreover, previous studies of pond ecosystems have focused primarily on taxonomic richness and largely overlooked functional diversity.
2. This study examined the influence of local environmental and spatial factors on taxonomic and functional α and β diversity (including the turnover and nestedness-resultant components) of 17 high-altitude (~2,500 m above sea level) pond macroinvertebrate communities, in the Macun Cirque, Switzerland.
3. Spatial processes (pond connectivity) were important drivers for taxonomic α diversity, while local environmental variables (pond permanence and surface area) were important determinants of functional α diversity. Species turnover was the most important component of β diversity for taxonomic composition, and functional composition demonstrated a nested spatial pattern.
4. Variation in taxonomic and functional composition (and the turnover and nestedness components of β diversity) were determined by local environmental variables despite the limited environmental gradients within the pond network. No significant effects of spatial variables on community composition were recorded for either facet of diversity, indicating that compositional variation was determined at a local scale. Water temperature, depth and pond permanence were consistently the most important measured drivers of diversity.
5. Given the importance of both spatial and environmental variables in structuring taxonomic and functional diversity, landscape-scale conservation and management activities that aim to improve or protect high-altitude freshwater biodiversity should focus on maintaining connectivity among ponds and environmental heterogeneity, particularly pond surface area, water depth, and hydroperiod. Understanding the mechanisms driving taxonomic and functional diversity will be critically important for the management and conservation of macroinvertebrate communities in high-altitude pond networks in the face of climatic warming.

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