Effect of dietary Schizochytrium microalga oil and fish oil on plasma cholesterol level in rats          下载免费PDF全文

T. Komprda  O. Škultéty  S. Křížková  G. Zorníková  V. Rozíková  R. Krobot 《Journal of animal physiology and animal nutrition》2015,99(2):308-316

The purpose of the study was to test the hypothesis that the dietary oils with different content of n‐3 polyunsaturated fatty acids (PUFA) eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) affect plasma lipid level in rats in a different degree. The diets with 6% of fish oil (FO) and Schizochytrium microalga oil (SchO; EPA+DHA content in the diets 9.5 + 12.3 and 2.6 + 29.5% of the sum of total fatty acids, respectively) were used; the diet with 6% of safflower oil (high content of n‐6 PUFA linoleic acid, 65.5%; EPA+DHA content 0.7 + 0.9%) was used as a control. The difference between FO and SchO was established only in the case of plasma triacylglycerol (TAG) level: plasma TAG of the FO‐fed rats did not differ from the control rats (p > 0.05), while SchO decreased (p < 0.05) plasma TAG to 46% of the control. On the other hand, FO and SchO decreased (p < 0.05) total plasma cholesterol (TC) in rats in the same extent, to 73% of the control. Regarding the underlying mechanisms for the TC decrease, both SchO and FO up‐regulated hepatic Insig‐1 gene (181 and 133% of the control; p < 0.05), which tended (p = 0.15 and p = 0.19 respectively) to decrease the amount of hepatic nSREBP‐2 protein (61 and 66% of the control). However, neither SchO nor FO influenced hepatic 3‐hydroxy‐3‐methyl‐glutaryl‐CoA reductase gene expression (p > 0.05); SchO (but not FO) increased (p < 0.05) low‐density lipoprotein receptor mRNA in the liver. It was concluded that the decrease of total plasma cholesterol might be caused by an increased cholesterol uptake from plasma into the cells (in the case of SchO), but also by other (in the present study not tested) mechanisms.  相似文献   

Radiography,Computed Tomography and Magnetic Resonance Imaging of Craniofacial Structures in Pig     

M. Kyllar  J. Štembírek  I. Putnová  L. Stehlík  S. Odehnalová  M. Buchtová 《Anatomia, histologia, embryologia》2014,43(6):435-452

The pig has recently become popular as a large animal experimental model in many fields of biomedical research. The aim of this study is to evaluate the basic anatomical structures in the head region of the pig to lay the groundwork for its practical clinical usage or pre‐clinical research in the future. We used three different diagnostic imaging methods: radiography, computed tomography (CT) and magnetic resonance imaging (MRI). The analysis showed that radiographic imaging is suitable only for general evaluation of the facial area of the pig skull. CT images showed excellent spatial definition of bony structures of the whole craniofacial area, and MRI images revealed fine soft tissue details. Radiography is preferentially suited to general assessment of bone structures of the facial skeleton; however, the thick layer of adipose tissue in the craniofacial region of the pig makes the imaging of some parts difficult or even impossible. CT is useful for revealing morphological details of mineralized tissues, whereas MRI is more suitable for soft tissue analysis and the detection of subtle pathologic changes in both bone and soft tissues. Therefore, before using pigs as an experimental model in craniofacial research, it is necessary to evaluate the suitability and disadvantages of potential imaging methods and how appropriate they are for accurate visualization of desired structures.  相似文献   

Can the structure of dormant cambium and the widths of phloem and xylem increments be used as indicators for tree vitality?     

Jožica Gričar  Špela Jagodic  Bogoslav Šefc  Jelena Trajković  Klemen Eler 《European Journal of Forest Research》2014,133(3):551-562

We investigated the structure and width of the dormant cambium and of the increments of phloem and xylem of Quercus robur to estimate their potential as indicators for tree vitality. The samples were taken from three woodlands, two in Slovenia [Krakovo forest (KRA) and Murska Suma (MUS)] and one in Croatia [Kobiljak (KOB)], with reported tree decline. The number of dormant cells seems to reflect the initial capacity of the cambium to accomplish cell division. With the exception of two trees at KRA, cell production was always higher on the xylem side than on the phloem side. The annual phloem increments were narrower, less variable among trees and with clear lower and upper limits. With increased cambial cell productivity, the share of the xylem in the total annual radial increment increased following a curvilinear function. In trees with an annual radial increment >3.5 mm, the xylem size represented more than 90 % of the total radial growth. The anatomical variables analyzed show that the most limiting environmental conditions seem to prevail at KRA, whereas the conditions at MUS seem to be most favorable in terms of radial growth. Analysis of the width and structure of xylem and phloem increments, the number of dormant cambial cells and their inter-relationships can provide additional information on the vitality of oaks.  相似文献   

Factors affecting the persistence of traditional agricultural landscapes in Slovakia during the collectivization of agriculture     

Juraj Lieskovský  Pavol Kenderessy  Jana Špulerová  Tibor Lieskovský  Peter Koleda  Felix Kienast  Urs Gimmi 《Landscape Ecology》2014,29(5):867-877

Collectivization of agriculture (1950s–1970s) was one of the most important periods in landscape development in Slovakia. Traditionally managed agricultural landscapes, that covered more than half of the Slovak territory, were transformed into large-scale fields and only fragments of traditional agricultural landscapes survived. We mapped the remaining traditional agricultural landscapes using aerial photos and historical maps. We then statistically analyzed the various geographical factors and their influence on the transformation process of traditional and collectivized fields, i.e., slope steepness, soil fertility, distance from settlements and isolation from regional capital cities. The comparison was performed using classification tree analysis. We constructed a set of decision rules that explain why fields were managed traditionally or collectivized. Our findings show that traditional agricultural fields were more likely to persist on steep terrain, less fertile soils, and on locations that were closer to the settlements, but more isolated from the regional capital cities. Steepness played the most important role: small-scale fields located on steep areas were not accessible to heavy machinery and therefore, frequently survived the collectivization. We show that the selected geographical factors are good explanatory variables for the collectivization of arable fields and orchards. For vineyards and grasslands, however, the explanatory power of the selected geographical factors is lower, and we suspect that other factors, not depicted in the analysis play an important role.  相似文献   

Flowering estimation in apple orchards by image analysis     

Marko Hočevar  Brane Širok  Tone Godeša  Matej Stopar 《Precision Agriculture》2014,15(4):466-478

Tree-specific management practice related to individual tree physiological condition is necessary for higher quality and quantity in apple fruit production. Detection of apple flowering abundance based on analysis of HSL (hue, saturation, luminance) images was used to estimate the number of flower clusters (FC) of individual trees in a high density apple orchard. The image acquisition was performed with a still camera and an industrial color camera during the day and night. The FC estimation algorithm included HSL thresholding with parameter optimization. Three hypothetical, tree-specific management practices (sprayings) were assumed, using >25, >50 and >100 FC thresholds to carry out the practice. When an industrial camera was used for image acquisition during the daytime and hypothetical spraying was done by on/off criterion >100 FC per tree, 10 % incorrect executions were identified. Comparable FC counting performance was achieved by using a still camera or an industrial camera.  相似文献   

Evaluation of mulched drip irrigation for cotton in arid Northwest China   总被引：1，自引：0，他引：1  

Zaimin Wang  Menggui Jin  Jirka Šimůnek  Martinus Th. van Genuchten 《Irrigation Science》2014,32(1):15-27

Field experiments were conducted in arid Southern Xinjiang, Northwest China, for 3 years to evaluate sustainable irrigation regimes for cotton. The experiments involved mulched drip irrigation during the growing season and flood irrigation afterward. The drip irrigation experiments included control experiments, experiments with deficit irrigation during one crop growth stage, and alternative irrigation schemes in which freshwater was used during one growth stage and relatively saline water in the others. The average cotton yield over 3 years varied between 3,575 and 5,095 kg/ha, and the irrigation water productivity between 0.91 and 1.16 kg/m³. Crop sensitivities to water stress during the different growth stages ranged from early flowering-belling (most sensitive) > seedling > budding > late flowering-belling (least sensitive), while sensitivities to salt stress ranged from late flowering-belling > budding > seedling > early flowering-belling. Although mulched drip irrigation during the growing season caused an increase in salinity in the root zone, flood irrigation after harvesting leached the accumulated salts to below background levels. Numerical simulations, based on the 3-year experiments and extended by another 20 years, suggest that mulched drip irrigation using alternatively fresh and brackish water during the growing season and flood irrigation with freshwater after harvesting is a sustainable irrigation practice that should not lead to soil salinization.  相似文献   

HYDRUS simulations of the effects of dual-drip subsurface irrigation and a physical barrier on water movement and solute transport in soils   总被引：2，自引：1，他引：1  

Mohammad N. El-Nesr  A. A. Alazba  Jiří Šimůnek 《Irrigation Science》2014,32(2):111-125

Subsurface drip irrigation systems, compared to other irrigation systems, enhance the delivery of water and nutrients directly into the root zone. However, in light-textured soils, certain quantities of water may percolate below the root zone due to the subsurface position of drip lines and/or poor management of irrigation systems. The main objective of this paper is to evaluate three technologies to enhance a spatial distribution of water and solutes in the root zone and to limit downward leaching. The three technologies include (a) a physical barrier, (b) a dual-drip system with concurrent irrigation, and (c) a dual-drip system with sequential irrigation. To achieve this objective, we performed computer simulations using the HYDRUS (2D/3D) software for both bare and vegetated soils. The results indicate that the physical barrier is more efficient than dual-drip systems in enhancing the water distribution in the root zone while preventing downward leaching. On the other hand, the dual-drip system improves water distribution in sandy soils. Additionally, the dual-drip system with sequential irrigation, followed by the dual-drip system with concurrent irrigation, is the most efficient in limiting downward leaching of solutes.  相似文献   

Carbon, Nitrogen and Phosphorus Tranformations are Related to Age of a Constructe Wetland     

K. Zemanová  T. Picek  J. Dušek  K. Edwards  H. Šantrůčková 《Water, air, and soil pollution》2010,207(1-4):39-48

Two horizontal constructed wetlands with subsurface flow (CWs) of different age were monitored in a 2-year study. One of the CWs was new, while the second one had been in operation for 5 years in the first year of study. Transformations of C, P, and N were measured in each CW in the substrate of the vegetated bed under both aerobic and anaerobic conditions, and their rates were compared. C was mineralized in both CWs under both aerobic and anaerobic conditions, but mineralization rates differed between the CWs; they were cca ten times higher in the established CW compared to the new CW. Dissolved reactive phosphorus (DRP) was immobilized under aerobic conditions but was mobilized under anaerobic conditions. DRP transformation was cca five times faster in the established CW. Nitrification occurred under aerobic conditions at similar rates in both CWs. NH₄ ⁺ concentration decreased under both aerobic and anaerobic conditions, but there was large variability. The age of the CW affected C mineralization rates and DRP immobilization rates under aerobic conditions and mobilization rates under anaerobic conditions; they increased as the CWs maturated, while no effect of CW age was observed on nitrogen removal rates.  相似文献   

Meiosis and pollen grain viability in Helianthus mollis,Helianthus salicifolius,Helianthus maximiliani and their F1 hybrids with cultivated sunflower     

Jovanka Atlagić  B. Dozet  D. Škoric 《Euphytica》1995,81(3):259-263

Three diploid perennial sunflower species are useful for variety improvement: Helianthus mollis, because of sessile leaves, H. salicifolius, because of a high oil concentration, and H. maximiliani, a potential source of resistance to Sclerotinia sclerotiorum. The crossability of these species to cultivated sunflower was examined.Hybrids were obtained from eight combinations, with 3–15 F₁ plants per combination. The F₁'s exhibited the dominant phenotype of the wild species. Pollen viability varied between 32.1 and 69.9%. Meiosis was irregular in the F₁ hybrids. At diakinesis, bivalents (62.7–97.9% of meiocytes), univalents (0–31.23%), and multivalents (3.84–7.68%) were detected. At anaphase I, chromosome bridges were detected in 6.77 to 11.44% of meiocytes. Fast chromosomes in metaphase I, and lagging chromosomes in anaphase I and telophase II were evidenced in a high percentage of meiocytes.  相似文献   

Characterization of isozyme variation in walnut(Juglans regia L.)     

A. Solar  J. Smole  F. Štampar  M. Viršček-Marn 《Euphytica》1994,77(1-2):105-112

Summary Four leaf enzymes malate dehydrogenase (MDH), 6-phosphogluconate dehydrogenase (6PGD), peroxidase (PX) and aspartate aminotransferase (AAT) of 17 walnut cultivars and two pollen enzymes malate dehydrogenase (MDH) and 6-phosphogluconate dehydrogenase (6PGD) of 15 walnut cultivars were analysed using horizontal starch gel electrophoresis. Walnut cultivars of different origin exhibited different numbers of electrophoretic bands and also different relative mobility. Different activity levels and phenotypic groups were detected in studied enzyme systems. Pollen enzymes revealed higher variability than enzymes extracted from the leaves. 15 walnut cultivars were classified into 10 malate dehydrogenase phenotypic groups and 14 6-phosphogluconate dehydrogenase phenotypic groups based on pollen analyses. 17 cultivars were classified into 9 peroxidase phenotypic groups and 7 6-phosphogluconate dehydrogenase phenotypic groups based on analyses of leaves. All of the 15 walnut cultivars could be identified and distinguished with electrophoretic analyses of MDH and 6PGD from the pollen while only 10 cultivars were distinguishable with analyses of 6PGD and PRX from the leaves. No variability useful for cultivar identification was observed in MDH and AAT from the leaves.  相似文献