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21.
Apparent nitrogen‐use efficiency of the applied mineral N (NUEmin) in effluent from biodigested plant material (BE; C : Norg ratio 14:1; mineral N–to–total N ratio 0.5:1) and a nitrate‐based inorganic fertilizer (IF), both applied at two rates was investigated in a six‐month pot experiment with Italian ryegrass (Lolium multiflorum Lam.). Dry‐matter (DM) production was 7% lower and total amount of N in aboveground biomass was 8% lower in BE than in IF at 40 d after sowing (DAS), equal at 81 DAS, and higher in BE than in IF at 136 and 172 DAS. NUEmin calculated on the basis of accumulated N in aboveground biomass of ryegrass in fertilized treatments compared to a control without N application was significantly lower in BE than in IF up to the third cut (136 DAS). Total NUEmin, total N recovery, and amount of foliage DM were similar for both fertilizers at the end of the experiment. Root biomass, total DM produced including roots and stubble, the fraction of root N to total plant N, and soil mineral N at 172 DAS were higher for BE than for IF. Mineral N applied with biogas‐reactor effluent was almost as effective as the nitrate‐based mineral fertilizer used for comparison. Within the six‐month experimental period net N mineralization, estimated at 12% of organic N in effluent, was not substantial. Hence, the organic compounds in the effluent were relatively recalcitrant. 相似文献
22.
Segner H Sundh H Buchmann K Douxfils J Sundell KS Mathieu C Ruane N Jutfelt F Toften H Vaughan L 《Fish physiology and biochemistry》2012,38(1):85-105
This brief review focuses on health and biological function as cornerstones of fish welfare. From the function-based point
of view, good welfare is reflected in the ability of the animal to cope with infectious and non-infectious stressors, thereby
maintaining homeostasis and good health, whereas stressful husbandry conditions and protracted suffering will lead to the
loss of the coping ability and, thus, to impaired health. In the first part of the review, the physiological processes through
which stressful husbandry conditions modulate health of farmed fish are examined. If fish are subjected to unfavourable husbandry
conditions, the resulting disruption of internal homeostasis necessitates energy-demanding physiological adjustments (allostasis/acclimation).
The ensuing energy drain leads to trade-offs with other energy-demanding processes such as the functioning of the primary
epithelial barriers (gut, skin, gills) and the immune system. Understanding of the relation between husbandry conditions,
allostatic responses and fish health provides the basis for the second theme developed in this review, the potential use of
biological function and health parameters as operational welfare indicators (OWIs). Advantages of function- and health-related
parameters are that they are relatively straightforward to recognize and to measure and are routinely monitored in most aquaculture
units, thereby providing feasible tools to assess fish welfare under practical farming conditions. As the efforts to improve
fish welfare and environmental sustainability lead to increasingly diverse solutions, in particular integrated production,
it is imperative that we have objective OWIs to compare with other production forms, such as high-density aquaculture. However,
to receive the necessary acceptance for legislation, more robust scientific backing of the health- and function-related OWIs
is urgently needed. 相似文献
23.
Trond Rafoss Knut Sælid Lars Fredrik Gyland 《Computers and Electronics in Agriculture》2010,74(2):336-340
The threat posed by invasive alien species to global crop production and biodiversity is recognized as one of the major drivers of global change today. Here we report on a successful implementation and operational use of new technology to support risk- and crisis management in the case of fighting an invasive plant disease. The open geospatial standards Web Feature Service Transaction (WFS-T) was implemented in software for GPS-enabled mobile phones communicating with a GeoServer backend in order to track down and eradicate disease outbreaks and susceptible host plants. This new technology offering georeferenced events online from field provides new possibilities for real time action in risk and crisis management. 相似文献
24.
Fredrik Andersen Olav ?ster?s Olav Reksen Nils Toft Yrjo T Gr?hn 《Acta veterinaria Scandinavica》2011,53(1):5
Background
This study was carried out to determine if an association exists between the shape of the lactation curve before it is influenced by the event of conception and the time from calving to conception in Norwegian dairy cattle. Lactation curves of Norwegian Red cows during 5 to 42 days in milk (DIM) were compared between cows conceiving between 43 and 93 DIM and cows conceiving after 93 DIM.Methods
Data from 23,049 cows, represented by one lactation each, with 219,538 monthly test days were extracted from the Norwegian Dairy Herd Recording System, which represents 97% of all Norwegian dairy cows. Besides veterinary treatments, these records also included information on daily milk yield at monthly test days. The data were stratified by parity groups (1, 2, and 3 and higher) and time to conception periods (43-93 DIM and >93 DIM). The sample was selected using the following selection criteria: conception later than 42 DIM, calving season July to September, no records of veterinary treatment and the level of energy fed as concentrates between 8.69 and 12.83 MJ. The shape of the lactation curves were parameterized using a modified Wilmink-model in a mixed model analysis. Differences in the parameters of the lactation curves with different conception times were evaluated using confidence intervals.Results
Lactation curves characterized by a low intercept and a steep ascending slope and a steep descending slope were associated with early conception across all parities. The peak milk yield was not associated with time of conception.Conclusions
A practical application of the study results is the use of the shape of the lactation curve in future herd management. Groups of cows with impaired reproductive performance may be identified due to an unfavorable shape of the lactation curve. Monitoring lactation curves and adjusting the feeding strategy to adjust yield therefore may be useful for the improvement of reproductive performance at herd level. 相似文献25.
Lamberth C Cederbaum F Jeanguenat A Kempf HJ Zeller M Zeun R 《Pest management science》2006,62(5):446-451
Novel types of anti-oomycetic compounds have been designed and prepared. The synthetic approach to these mandelamides is outlined. Biological data demonstrate their high efficacy against important plant diseases such as tomato and potato late blight (Phytophthora infestans De Bary) and grape downy mildew (Plasmopara viticola Berliner & de Toni). Structure-activity relationship studies are discussed. The new development product mandipropamid is presented. 相似文献
26.
27.
Liva Pupure Janis Varna Roberts Joffe Fredrik Berthold Arttu Miettinen 《Wood material science & engineering》2020,15(2):76-86
ABSTRACTComposites formed from wood fibers and man-made cellulosic fibers in PLA (polylactic acid) matrix, manufactured using sheet forming technique and hot pressing, are studied. The composites have very low density (due to high porosity) and rather good elastic modulus and tensile strength. As expected, these properties for the four types of wood fiber composites studied here improve with increasing weight fraction of fibers, even if porosity is also increasing. On the contrary, for man-made cellulosic fiber composites with circular fiber cross-section, the increasing fiber weight fraction (accompanied by increasing void content) has detrimental effect on stiffness and strength. The differences in behavior are discussed attributing them to fiber/ fiber interaction in wood fiber composites which does not happen in man-made fiber composites, and by rather weak fiber/matrix interface for man-made fibers leading to macro-crack formation in large porosity regions. 相似文献
28.
A screening tool for vulnerability assessment of pesticide leaching to groundwater for the islands of Hawaii, USA 总被引:1,自引:0,他引:1
This paper describes an updated version of a screening tool for groundwater vulnerability assessment to evaluate pesticide leaching to groundwater, based on a revised version of the attenuation factor. The tool has been implemented in a geographical information system (GIS) covering the major islands of the state of Hawaii, USA. The Hawaii Department of Agriculture currently uses the tool in their pesticide evaluation process as a first-tier screening tool. The basic soil properties and pesticide properties necessary to compute the index, and estimates of their uncertainty, are included in the GIS. Uncertainties in soil and pesticide properties are accounted for using first-order uncertainty analysis. Classifications of pesticides as 'likely', 'uncertain' or 'unlikely' to leach are made on the basis of the uncertainty and a comparison of the revised attenuation factor with values and uncertainties of two reference chemicals. The reference chemicals represent what are considered to be a 'leachable' and a 'non-leachable' pesticide under Hawaii conditions. It is concluded that the tool is suitable for screening new and already used pesticides for the islands of Hawaii. However, the tool is associated with uncertainties that are not accounted for, so a conservative approach with respect to interpretation of the results and selection of pesticide parameters used in the tool is recommended. 相似文献
29.
Ronquist F Larget B Huelsenbeck JP Kadane JB Simon D van der Mark P 《Science (New York, N.Y.)》2006,312(5772):367; author reply 367
Mossel and Vigoda (Reports, 30 September 2005, p. 2207) show that nearest neighbor interchange transitions, commonly used in phylogenetic Markov chain Monte Carlo (MCMC) algorithms, perform poorly on mixtures of dissimilar trees. However, the conditions leading to their results are artificial. Standard MCMC convergence diagnostics would detect the problem in real data, and correction of the model misspecification would solve it. 相似文献
30.
Ian C Fulton John A Stick Fredrik J Derksen 《Veterinary Clinics of North America: Equine Practice》2003,19(1):189-208, viii
Left laryngeal hemiplegia is a frustrating condition for the equine athlete and equine veterinarian. Treatment for the past 30 years has centered on the prosthetic laryngoplasty ("tie-back") with or without ventriculectomy. Laryngeal reinnervation has been used successfully in people and has been shown experimentally to benefit affected horses. This article reviews equine laryngeal reinnervation using the nerve muscle pedicle graft and describes the surgical technique, its complications, and the follow-up in 146 cases treated over the past 10 years. Also discussed is ongoing research into stimulation studies to improve the success of equine laryngeal reinnervation. 相似文献