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The Goettingen minipig is a laboratory animal especially developed for medical research. For easy and comfortable handling during experiments, and to minimize costs, a low BW is essential. To breed for an even smaller minipig, genetic parameters for BW were estimated using a random regression model (RRM). The RRM was calculated using random animal, common litter environment, and permanent environment effects, respectively. Regressions for the random effects in the RRM were modeled using Legendre polynomials from second to fourth order of fit in different combinations. The model was applied to a data set that focused on the time period from 30 to 400 d of age. Eight age classes were built to consider heterogeneous residual variances. The heritabilities were moderate and ranged from 0.211 (375 d of age) to 0.254 (275 d of age). The variances initially decreased and then increased toward the end of the examined time period for permanent environment and litter effects. Genetic and phenotypic correlations between BW in different age classes decreased with increasing distance between age classes. The major eigenfunction showed positive values throughout the whole trajectory (i.e., a selection for low BW had positive effects on this trait throughout the whole range of time). On the basis of the estimated genetic parameters, a breeding scheme can be created to develop genetically smaller Goettingen minipigs in the future.  相似文献   
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Bacterial soft rots are a serious limitation to the production of orchids and other horticultural plants. Here, the characterization of causative bacteria isolated from Phalaenopsis orchids showing symptoms, from a commercial production site, is reported. The most commonly isolated bacteria were identified as Dickeya spp. Partial sequencing of 16S rDNA, fliC and dnaX showed diversity among the isolates and divided the isolates into two groups, with greatest similarity to previously reported undefined Dickeya lineages from orchids (UDL‐3 and UDL‐4). Two isolates (B16, S1) were sequenced using next‐generation sequencing, which has provided draft genomes of these two isolates for further studies (Ali? et al., 2015 ). Newly developed fliC‐based lineage‐specific quantitative real‐time PCR assays were used to distinguish among the lineages and to assess their relative abundances in diseased tissues. Virulence and aggressiveness comparison tests in vivo on Phalaenopsis orchids, potato plants and witloof chicory leaves indicated high virulence and extreme maceration potential of these novel Dickeya isolates, compared to a reference panel of other Dickeya spp. Pantoea cypripedii (formerly Pectobacterium cypripedii), which has previously been reported as a soft rot pathogen of orchids, was not detected, and isolates obtained from culture collections did not cause symptoms on artificially infected Phalaenopsis orchids.  相似文献   
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The objective of this study was to determine whether phagocytic activity in blood and proliferation of peripheral blood lymphocytes are impaired during perinatal period. The study comprised 18 primiparous sows (Landras × Large White) free from clinical signs of diseases. During the experiment blood samples were collected three times from each sow. Sampling was performed on three different dates, always from all sows at once. At the first date of sampling sows were 21 ± 3 days before parturition, at the second date ± 1 day around parturition time and at the third date 21 ± 3 days after parturition. Phagocytic activity of monocytes and granulocytes was assessed in heparinized whole blood with addition of fluorescein isothiocyanate (FITC)-labelled opsonized bacteria Escherichia coli and the percentage of phagocytes which have ingested bacteria was measured as fluorescence activity by flow cytometry. The percentage of phagocyting monocytes and granulocytes was lowest at parturition (72.6 ± 16.37, 52.4 ± 20.59) and significantly increased within the next 21 ± 3 days (86.5 ± 6.16, 69.89 ± 5.80). Similarly, the phytohemagglutinin (PHA) (10 μg/ml) stimulated in vitro lymphocyte response was suppressed by parturition in primiparous sows (p < 0.001).  相似文献   
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Breeding for low body weight in Goettingen minipigs.   总被引:1,自引:0,他引:1  
The Goettingen minipig is a laboratory animal with increasing popularity in medical research. To get a genetically smaller minipig, a new breeding scheme with a focus on weight reduction has to be developed. Therefore, 19 505 body weight measurements of 3461 Goettingen minipigs were analysed with multiple trait models and random regression models (RRM) for the estimation of genetic parameters. Heritabilities were moderate with slightly higher values estimated with the RRM. Genetic correlations between body weight measurements at different ages were decreasing with increasing time lag between the measurements. An operational breeding goal for relative weight reduction RWR is suggested in which the weight reduction in each age class is expressed as per cent of the actual body weight and is weighted according to the proportion of animals sold in this age class. Expected genetic progress was calculated for two different selection ages (80 and 150 days). Selection at age 150 days leads to an expected genetic progress of 3.9 % RWR per year. And it is shown how the selection for RWR will modify the shape of the growth curve. On the basis of these results, a new breeding scheme with a focus on weight reduction can be implemented, which also has to account for correlated undesirable effects, like decline of fertility and increased rate of inbreeding.  相似文献   
6.
Among other factors, harvesting intensity in private forests depends on property, resource and forest owner characteristics. The research was conducted in Slovenia, a Central European country with very fragmented and small-scale forest property, a large number of owners and co-owners and a long tradition of sustainable forest management. In the nationwide study, data from the Land and Property Register and forest inventory database were used to build a logistic regression model to identify factors that influence harvesting intensity. The results of the model revealed that growing stock, share of conifers, share of forest area under regeneration, total size of forest property in owner- and co-ownership, parcel size and accessibility of the forest area to forest operations increase harvesting intensity. Slope, number and age of owners and co-owners, and skidding distance negatively influence harvesting intensity. The results can offer useful information for policy and decision makers for formulating policy as well as implementing the most suitable mix of policy instruments.  相似文献   
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Renewable energy sources have received significant attention in European countries as a result of increasing dependence on energy imports and concerns over high prices of fuels and climate change. Although private forests in Croatia account for less than one quarter of all forests, they may play an important role in woody biomass energy production, due to their underutilized exploitation. The objective of this paper is to identify the willingness of private forest owners to supply woody biomass and to understand how this willingness is affected by certain owner, management and forest property characteristics. A survey conducted in Croatia in 2012 of a random sample of 350 private forest owners shows that almost half of them were willing to supply woody biomass. A random utility model was used to determine the factors influencing private forest owners’ willingness to supply woody biomass. The results showed that willingness to supply woody biomass was influenced by property size, management objectives (production of fuel wood for personal needs and using the forest for outdoor recreation), cooperation with other forest owners and owner age. In order to enhance woody biomass mobilization from private forests it is important to identify the owners who are willing to supply it and to provide them with financial and administrative support using a mix of developed forest policy instruments.  相似文献   
8.
Dandelion (Taraxacum officinale agg.) is a common forb species in grasslands in Europe. Although sometimes regarded as a valuable forage herb, it may become a weed, especially in arable land. There is limited information on the response of Taraxacum to long‐term grassland management practices. Therefore, we analysed cover and dry‐matter standing biomass of Taraxacum in a long‐term (1998–2012) grazing experiment on an Agrostis capillaris grassland. The following treatments were laid out on formerly abandoned grassland: (i) intensive grazing (IG); (ii) extensive grazing (EG); (iii) first cut followed by intensive grazing (ICG); (iv) first cut followed by extensive grazing (ECG); and (v) unmanaged grassland (U). During the first 10 years, all defoliation treatments (i–iv) supported the presence of Taraxacum, and the lowest proportion was recorded in the unmanaged treatment (U). During the final 7 years of the study, combined cutting and grazing promoted Taraxacum cover more than that of grazing only (ICG > IG > ECG > EG). Cover of Taraxacum was negatively affected by increasing sward height where Taraxacum plants had lower fitness. Due to the relatively strong relationship between percentage cover of Taraxacum and its dry‐matter biomass, percentage cover could be used as a simple method for the assessment of biomass of Taraxacum in a sward. Results are discussed in the context of adapting the management of A. capillaris grassland as a simple method for control of Taraxacum abundance, particularly in situations of extensification or abandonment.  相似文献   
9.
Serum samples of 746 shot wild boars collected throughout Slovenia during the hunting season of 2005/2006 were examined for the presence of antibodies against rabies virus: 541 samples were collected in areas subjected to yearly antirabies vaccination, and 205 samples were collected in areas where preventive antirabies vaccination was not practised. Using a modified enzyme-linked immunosorbent assay (ELISA), in 209 out of 746 sera (28%) the levels of antibodies against rabies virus were higher than 0.5 IU/ml and deemed positive. A total of 173/541 (32%) and 36/205 (18%) samples were positive in the vaccinated and nonvaccinated areas, respectively. Further analysis of 191 out of the 746 samples using the fluorescent antibody virus neutralisation (FAVN) test revealed the presence of antibodies against rabies virus in 122/191 (64%) samples. This is the first extended research reporting that antibodies against rabies virus that originate from preventive oral vaccination targeting the fox population are present in wild boar.  相似文献   
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