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1.
1. Fourteen by‐products of oil refining, selected for their variability in free fatty acid and unsaponifiable contents, were analysed chemically with the objective of relating the determined ME values of the products to chemical composition by means of multiple linear regression analysis. Refined sunflower oil was included as a reference fat.

2. Twenty‐one 2‐week‐old chicks were used to determine fat digestibilities and AMEn values of diets, using the total collection method. Fats were included in a wheat‐soyabean meal diet at 100 g/kg. Multiple linear regression analysis was used to express the ME values of fats as functions of the parameters measured (moisture, gross energy, impurities, unsaponifiables, non eluted material, free fatty acid content, unsaturated: saturated ratio, peroxide value, TBA test).

3. The ME of the fat products lay in the range 12.62 to 24.35 MJ/kg, and 29.26 MJ/kg for refined sunflower oil. Free fatty acid content of the fats was shown to be a poor predictor of their ME values, whereas non eluted material (NEM) of the fat products showed a good correlation with their ME. A regression equation could be derived (R2 = 0.6548; SEE = 2–0064) with the unsaturated: saturated ratio (U:S) and NEM. An ME prediction equation based on the U:S, NEM and unsaponifiable content is also proposed (R2 = 0–7168; SEE= 1.9058).  相似文献   

2.
This paper describes a sensitive isocratic HPLC/ECD method developed for the determination of rosmarinic acid (RA) in plant material, animal feed, and pig plasma. The plasma sample preparation only includes protein precipitation and adjustment of the pH. The applicability of the method was tested on plasma samples of pigs that were exposed to a 91-day oral intake of RA via feed enriched by aerial parts of Prunella vulgaris. The plasma was directly analyzed using the method described as well as after enzymatic hydrolysis. When no hydrolysis step was included, RA and caffeic acid (CA) were quantified in the plasma. In hydrolyzed plasma samples, several other metabolites were determined, including dihydrocaffeic, ferulic, and dihydroferulic acid. The dual-channel coulometric detection employed, as an alternative to mass spectrometry, offers good selectivity and sensitivity owing to the electrochemical properties of the phenolic constituents.  相似文献   
3.
European Journal of Forest Research - Ecosystem services are investigated from many perspectives, but there are very few studies comparing the perception of forest and demand for forest ecosystem...  相似文献   
4.
Fractals and search paths in mammals   总被引:6,自引:0,他引:6  
Bascompte  Jordi  Vilà  Carles 《Landscape Ecology》1997,12(4):213-221
The fractal index by Katz and George (1985) for thecharacterization of planar curves is applied to wolf search pathsrecorded by radio-telemetry. All the sets of paths studied showspatial patterns whose complexity is between a straight line anda true random walk. Females fractal dimensions show significantchanges throughout the year, depending on the state of their lifecycle (normal, breeding and wandering). There are alsodifferences between males and females, but not between adults andnon-adults. The results are discussed with regard to wolffood-search strategies.  相似文献   
5.
With increasing demand for sustainable production, the need to effectively utilise site-based resources increases. One such resource is the remaining crop residues, both above and below ground, after harvest. In order to assess the magnitude of this resource, this study determined the plant nutrient contribution of residues from 17 different crops in seven different regions of Slovakia over a nine-year period. The soil profile 0.0–0.3?m was taken into account at belowground residues sampling. The results showed that winter rape, mustard, corn maize, triticale, winter rye with straw and sunflower left the most residues, exceeding 8 tons of dry biomass per hectare. Root crops (sugar beet, potatoes) and peas left less than 3 tons of residual dry biomass per hectare. Using these data, the nutrient potential coefficient, i.e. the amount of nutrients left by production of one ton of the main product was calculated by polynomial regression. With these coefficients and the known yield of a given crop, it was possible to calculate how much nitrogen, phosphorus and potassium each crop leaves in the soil after harvest. It was found that the amount of nitrogen left ranged from 20 to 132?kg, phosphorus from 2 to 24?kg and potassium from 13 to 218?kg per hectare. This has to be taken into account when calculating the fertiliser requirement of the subsequent crop in order to achieve better resource utilisation, thereby reducing the risk of eutrophication and improving farm profits by reducing expenditure on fertiliser.  相似文献   
6.
Mitochondrial DNA sequences isolated from ancient dog remains from Latin America and Alaska showed that native American dogs originated from multiple Old World lineages of dogs that accompanied late Pleistocene humans across the Bering Strait. One clade of dog sequences was unique to the New World, which is consistent with a period of geographic isolation. This unique clade was absent from a large sample of modern dogs, which implies that European colonists systematically discouraged the breeding of native American dogs.  相似文献   
7.
European Journal of Forest Research - In the time of ongoing climate change and the increasing area of post-mining landscape, the successful afforestation of reclamation sites by suitable adaptive...  相似文献   
8.
Soviet and Russian pedologists, ecologists, geobotanists, geographers, and other specialists created a large set of maps on the territory of the former Soviet Union. In most cases, these maps were published; at present, they are available as hardcopies. Their digitization clearly shows various merits and demerits of thematic maps on the territory of the Soviet Union and Russia.  相似文献   
9.
A methodology for comparing soil map of different dates in order to reveal changes in the soil cover is discussed. The analysis of a set of the maps of soil salinization on one of the farms in the Golodnaya Steppe region of Uzbekistan is used as an example. It is shown that traditional methods of comparing two maps developed in different years (normally, with an interval of five years and more) are low informative for the assessment of soil salinization dynamics. The suggested methodology assumes simultaneous analysis of several maps in order to reveal the trends in soil salinization. However, even in this case, the obtained results do not adequately characterize the dynamics of soil salinization on irrigated fields. It is argued that the direction of soil salinization–desalinization processes is an improper characteristic in this case. In order to understand the dynamics of soil salinization, the maps showing the dynamism of soil salinity and the maximum changes in the degree of salinity can be applied. A series of the compared maps make it possible to describe the changes in the soil cover related to salinization–desalinization processes. The high dynamism of these processes against the background of a virtually stable pool of soluble salts in the 1-m-deep soil layer is shown for the considered farm.  相似文献   
10.
Over the past decade, the Zaire strain of Ebola virus (ZEBOV) has repeatedly emerged in Gabon and Congo. Each human outbreak has been accompanied by reports of gorilla and chimpanzee carcasses in neighboring forests, but both the extent of ape mortality and the causal role of ZEBOV have been hotly debated. Here, we present data suggesting that in 2002 and 2003 ZEBOV killed about 5000 gorillas in our study area. The lag between neighboring gorilla groups in mortality onset was close to the ZEBOV disease cycle length, evidence that group-to-group transmission has amplified gorilla die-offs.  相似文献   
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