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31.
Sport performance in dressage and show jumping are two important traits in the breeding goals of many studbooks. To determine the optimum selection scheme for jumping and dressage, knowledge is needed on the genetic correlation between both disciplines and between traits measured early in life and performance in competition in each discipline. This study aimed to estimate genetic parameters to support decision‐making on specialization of breeding horses for dressage and show jumping in Dutch warmblood horses. Genetic correlations between performance of horses in dressage and show jumping were estimated as well as the genetic correlation between traits recorded during studbook‐entry inspections and performance in dressage and show jumping competitions. The information on competition comprised the performance of 82 694 horses in dressage and 62 072 horses in show jumping, recorded in the period 1993–2012. For 26 056 horses, information was available for both disciplines. The information on traits recorded at studbook‐entry inspections comprised 62 628 horses, recorded in the period 1992–2013. Genetic parameters were estimated from the whole dataset and from a subset without horses recorded in both disciplines. Additionally, the genetic parameters were estimated in three different time periods defined by horses' birth year. The genetic correlation between dressage and show jumping in the whole dataset was ?0.23, and it was ?0.03 when it was estimated from horses recorded in only one discipline. The genetic correlation between dressage and show jumping was more negative in the most recent time period in all the cases. The more negative correlation between disciplines in more recent time periods was not reflected in changes in the correlations between competitions traits and the traits recorded in the studbook‐first inspection. These results suggest that a breeding programme under specialization might be most effective defining two separate aggregate breeding goals for each of the disciplines.  相似文献   
32.
In many areas, picking wild berries constitutes an important forest commodity offering food, recreational services, and revenues. Intensified forest management has negatively affected bilberry yields. In this study, regional-level scenario analyses were conducted to investigate the effects of four approaches to the inclusion of bilberry yields on the economics, management, and resulting forest structures in North Karelia. The current approach ignoring bilberries resulted in decreasing bilberry yields and increasing younger forests. When bilberries were valued at market price (1.72?€?kg?1), bilberry yields still decreased despite the fact that forest management were slightly modified to favour bilberry. Adding non-declining sustainability constraints to bilberry yields resulted in a slightly lower total net present value of timber and bilberry since forest management favoured longer rotation lengths, which increased bilberry yields. Similar effects occurred when the bilberry price was tripled to include the implicit ecosystem benefits of bilberries. When forests were managed only for bilberries (timber zero-priced), bilberry yields started to increase immediately resulting in 1.5-fold difference in 50 years as compared to timber only scenario. In conclusion, managing forests for both timber and bilberry production has rather minor effects on economics, but it can have clear positive effect on bilberry yields.  相似文献   
33.
Chitooligosaccharides (CHOS) are homo- or heterooligomers of N-acetylglucosamine and D-glucosamine. CHOS can be produced using chitin or chitosan as a starting material, using enzymatic conversions, chemical methods or combinations thereof. Production of well-defined CHOS-mixtures, or even pure CHOS, is of great interest since these oligosaccharides are thought to have several interesting bioactivities. Understanding the mechanisms underlying these bioactivities is of major importance. However, so far in-depth knowledge on the mode-of-action of CHOS is scarce, one major reason being that most published studies are done with badly characterized heterogeneous mixtures of CHOS. Production of CHOS that are well-defined in terms of length, degree of N-acetylation, and sequence is not straightforward. Here we provide an overview of techniques that may be used to produce and characterize reasonably well-defined CHOS fractions. We also present possible medical applications of CHOS, including tumor growth inhibition and inhibition of TH2-induced inflammation in asthma, as well as use as a bone-strengthener in osteoporosis, a vector for gene delivery, an antibacterial agent, an antifungal agent, an anti-malaria agent, or a hemostatic agent in wound-dressings. By using well-defined CHOS-mixtures it will become possible to obtain a better understanding of the mechanisms underlying these bioactivities.  相似文献   
34.
Maturing male and female Atlantic salmon (Salmo salar L.) were held under three temperature regimes for 10 weeks between September and December: warm (constant 14–16 °C), ambient (decreasing from 11 to 5 °C), and cold (decreasing from 7 to 3 °C). Blood samples were analyzed for plasma steroid levels, and the fish were inspected for the presence of expressible milt (total volume and spermatocrit) and ovulation weekly. Samples of eggs were dry-fertilized with milt stripped from three males held at the same temperatures and incubated until the eyed stage. In females, levels of plasma testosterone (T) and 17β-oestradiol (E2) dropped as ovulation approached, concurrent with a rapid increase in levels of plasma 17α,20β-dihydroxy-4-pregnen-3-one (17,20β-P). In males, levels of T and 11-ketotestosterone (11-KT) peaked 2–3 weeks after the first appearance of expressible milt, while levels of 17,20β-P increased steadily and did not exhibit a definite peak. Exposure of females to cold water amplified and advanced the profiles of all three steroids compared with the ambient group, and increased the survival rates to the eyed egg stage. Cold water had no immediate effect on the male steroid profiles, but later, higher levels of 17,20β-P were evident compared with both the ambient controls and the warm water group, while the effects on 11-KT and T were more variable. Exposure to warm water completely inhibited both milt production and ovulation. Moreover, warm water modulated the steroid profiles of the males with lower 11-KT levels compared with ambient controls and lower 17,20β-P level compared with cold-water-treated males. In females, warm water resulted in total inhibition of the peri-ovulatory peak in 17,20β-P and prevented the normal decline of T and E2 levels associated with ovulation. The findings of the present study are highly relevant for broodstock management in aquaculture, as well in understanding the impact of climate change/temperature variability on wild salmon spawning.  相似文献   
35.
Knowledge about the importance of physical habitat characteristics to the breeding site selection of birds is a prerequisite for understanding their breeding habitat ecology and distribution, as well as managing their habitats. Geographical information systems (GIS) and existing digital data archives provide new possibilities for the quantitative and cost-effective assessment of coastal breeding habitats of birds. We tested the applicability of GIS and digital data archives for the analysis of coastal bird habitats by conducting a multivariate analysis on the relationship between physical island characteristics and the breeding site selection of 15 species of ducks, waders, larids and alcids in 2001-2005 in the fragmented archipelago coast of south-western Finland. We used GIS and environmental databases containing shoreline, bathymetry and elevation data to calculate five physical parameters for 71 small islands and their vicinity. Island area was generally the most important factor determining the presence of the species, but also water depth, shore openness, and island elevation were important for some species. The differences and similarities in habitat preferences within and between species groups seem to reflect the breeding habitat ecology of the species. GIS and spatial data archives are becoming increasingly valuable for research and development, as well as administrative tasks. Our results indicate that physical island characteristics affect the breeding site selection and the distribution of our target species, and that GIS and digital data archives provide applicable information on the breeding habitats of coastal birds and thus function as a tool for conservation and management.  相似文献   
36.
Vitellogenin (VTG) synthesis was induced by repeated injections of estradiol-17 in juvenile Atlantic halibut (Hippoglossus hippoglossus). VTG eluted as a large, phosphoprotein containing peak on DEAE-Sephacel chromatography of plasma from estradiol-17 treated juvenile and mature female, but not mature male halibut. A purification procedure for Atlantic halibut VTG was developed, where VTG was precipitated with MgCl2, EDTA and distilled water, and the precipitated protein submitted to anion exchange chromatography on DEAE-Sephacel. Precipitated VTG eluted as a broad, partly dissociated peak on DEAE-Sephacel, when chromatography was run at 4°C, but the protein appeared intact when analysed both by SDS PAGE and native PAGE. DEAE-Sephacel chromatography at room temperature resulted in an irregular elution pattern and a dissociated protein fraction, as analysed by SDS PAGE. Biochemical characterization of VTG showed that the molecular mass of the monomer was ca 160 kDa, as estimated by SDS-PAGE. The total lipid content was 19.8% w/w, with 64%, or 12.7% of the total weight, as phospholipid. Protein bound phosphorus constituted 0.62% w/w of halibut VTG. Plasma dilution curves from mature and maturing female halibut were parallel with a dilution curve from halibut egg yolk homogenate in an homologous RIA. Plasma from mature male, but not juvenile halibut crossreacted with the VTG antiserum.  相似文献   
37.
Most Warmblood horse studbooks aim to improve the performance in dressage and show jumping. The Dutch Royal Warmblood Studbook (KWPN) includes the highest score achieved in competition by a horse to evaluate its genetic ability of performance. However, the records collected during competition are associated with some aspects that might affect the quality of the genetic evaluation based on these records. These aspects include the influence of rider, censoring and preselection of the data. The aim of this study was to quantify the impact of rider effect, censoring and preselection on the genetic analysis of competition data of dressage and show jumping of KWPN. Different models including rider effect were evaluated. To assess the impact of censoring, genetic parameters were estimated in data sets that differed in the degree of censoring. The effect of preselection on variance components was analysed by defining a binary trait (sport‐status) depending on whether the horse has a competition record or not. This trait was included in a bivariate model with the competition trait and used all horses registered by KWPN since 1984. Results showed that performance in competition for dressage and show jumping is a heritable trait (h2 ~ 0.11–0.13) and that it is important to account for the effect of rider in the genetic analysis. Censoring had a small effect on the genetic parameter for highest performance achieved by the horse. A moderate heritability obtained for sport‐status indicates that preselection has a genetic basis, but the effect on genetic parameters was relatively small.  相似文献   
38.
Drainage of peatlands affects the fluxes of greenhouse gases (GHGs). Organic soils used for agriculture contribute a large proportion of anthropogenic GHG emissions, and on-farm mitigation options are important. This field study investigated whether choice of a cropping system can be used to mitigate emissions of N2O and influence CH4 fluxes from cultivated organic and carbon-rich soils during the growing season. Ten different sites in southern Sweden representing peat soils, peaty marl and gyttja clay, with a range of different soil properties, were used for on-site measurements of N2O and CH4 fluxes. The fluxes during the growing season from soils under two different crops grown in the same field and same environmental conditions were monitored. Crop intensities varied from grasslands to intensive potato cultivation. The results showed no difference in median seasonal N2O emissions between the two crops compared. Median seasonal emissions ranged from 0 to 919?µg?N2O?m?2?h?1, with peaks on individual sampling occasions of up to 3317?µg?N2O?m?2?h?1. Nitrous oxide emissions differed widely between sites, indicating that soil properties are a regulating factor. However, pH was the only soil factor that correlated with N2O emissions (negative exponential correlation). The type of crop grown on the soil did not influence CH4 fluxes. Median seasonal CH4 flux from the different sites ranged from uptake of 36?µg CH4?m?2?h?1 to release of 4.5?µg?CH4?m?2?h?1. From our results, it was concluded that farmers cannot mitigate N2O emissions during the growing season or influence CH4 fluxes by changing the cropping system in the field.  相似文献   
39.
A field experiment with separately tile-drained plots was used to study the ability of oilseed radish (Rhaphanus sativus L.), as a cover crop sown after harvest of a main crop of cereals or peas, to reduce nitrogen (N) and phosphorus (P) leaching losses from a clay loam in southern Sweden over 6 years. In addition to oilseed radish in pure stand, two cover crop mixtures (hairy vetch (Vicia villosa) and rye (Secale cereale) for 3 years and oilseed radish in mixture with buckwheat (Fagopyrum esculentum) for 2 years) were tested. The cover crop plots (three replicates per treatment) were compared with unplanted plots as a control. Plots cropped with oilseed radish during autumn (August–November) had significantly smaller yearly mean N concentration in drainage water over 5 of 6 years compared with unplanted controls. Mineral N content in the soil profile in autumn was significantly less in oilseed radish plots than for control plots in all years. The cover crop mixtures of hairy vetch and rye or buckwheat and oilseed radish also showed the potential to reduce soil mineral N in autumn and N concentration in drainage water, compared with unplanted controls. The cover crops had no impact on P leaching. In conclusion, oilseed radish has the ability to reduce leaching losses of N, without increasing the risk of P leaching.  相似文献   
40.
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