共轭亚油酸对肉鸭的生产性能与屠体性状的影响研究

试验通过添加不同剂量的共轭亚油酸来探讨它对肉鸭的生产性能和屠体性状的影响。选用7日龄健康、体重相近的天府肉鸭84只(公母各半)(P>0.05),按单因素完全随机设计分4个处理,每个处理3个重复,共21只鸭,试验期35d。共轭亚油酸在基础日粮上分别添加1%,2%,3.5%。试验结果表明:①在肉鸭的生长期内,适量添加共轭亚油酸能够提高肉鸭的平均日增重和饲料转化率。在共轭亚油酸添加水平达2%时,促进了肉鸭生长,而添加3.5%水平时,却抑制了肉鸭的增重。②共轭亚油酸具有一定的营养重分配作用,提高了肉鸭的胸肌率、腿肌率;降低了腹脂率。在胸肌率方面,Ⅱ组、Ⅲ组、Ⅳ组比Ⅰ组(对照组)提高了0.5%(P>0.05),1.79%(P<0.05),2.5%(P<0.01);在腿肌率方面,Ⅱ组、Ⅲ组、Ⅳ组比Ⅰ组提高了1.1%(P>0.05),1.7%(P<0.05),2.7%(P<0.05);在腹脂率方面,Ⅱ组、Ⅲ组、Ⅳ组比Ⅰ组降低了8.9%(P>0.05),15.7%(P<0.05),18.6%(P<0.05)。     

Modelling the response of terrestrial ecosystems to acidification and desiccation scenarios

Changes in vegetation are often caused by changes in abiotic site factors, such as pH, nitrogen availability and soil moisture. It has been recognized that abiotic site factors are affected by atmospheric deposition and groundwater-table changes. In order to evaluate the effects of eutrophication, acidification and desiccation on site factors, the model SMART2 has been developed. For the Netherlands combinations of two acidification and two seepage scenarios (1990–2050) were evaluated with SMART2. The results are focused on pH, nitrogen availability and base saturation. Calculations were made for combinations of five vegetation structures on seven soil types and the five groundwater-table classes, using a 1 km² grid. Results showed that deposition reductions lead to a relatively fast improvement of the site factors, increase in pH and base saturation and decrease in N availability. Whereas a reduction in groundwater abstractions of 25% has little or no effect on the pH and N availability.     

Development of an indirect competitive ELISA for flumequine residues in raw milk using chicken egg yolk antibodies

To detect flumequine in raw milk, an indirect competitive enzyme-linked immunosorbent assay (ELISA) was developed. By carbodiimide conjugation, flumequine was conjugated to cationized bovine serum albumin (cBSA-flumequine) and to cationized ovalbumin (cOVA-flumequine). For the immunization of chickens, cBSA-flumequine was used, which allowed the isolation of specific chicken egg yolk immunoglobulins (IgY) for flumequine. As the coating antigen in the immunoassay, cOVA-flumequine was used. In the indirect competitive assay, standard flumequine was incubated together with the anti-flumequine antibodies. The antibody by which the lowest concentration of free flumequine that gives 50% inhibition of binding (IC50) was found in aqueous dilution was further tested for the applicability to detect flumequine in raw milk. An IC50 level in milk was reached that was about 5 times lower than in aqueous solution. So flumequine can be detected directly in raw milk at maximum residue level (50 microg/kg). No cross-reactivity was noticed with various related quinolones.     

Influence of explant source on in vitro axillary shoot formation in oak seedlings

In vitro shoot development was slower for apical shoot explants of young oak (Quercus robur L.) seedlings growing on Woody Plant Medium containing activated charcoal than for nodal shoot explants. The rate of in vitro shoot development was slowest in explants taken from seedlings that were undergoing rapid shoot elongation and most rapid in explants taken from seedlings that had stopped elongating and had fully expanded leaves. Maximum rooting was achieved on half-strength Woody Plant Medium containing activated charcoal. Rooting ability was not influenced by explant source.     

The Transportation and Lifting Facilities in Chongqing and the Industrialised Housing

This article introduces that there are good basic conditions and big development space for the industrialized housing development in Chongqing Municipality-the biggest municipality in the country.And it introduces the capabilities of horizontal transportation by land or sea and vertical lifting in Chongqing. And it puts forward that is more economical, reliable and safer than which has the advantages of best weight lifting capacity, service radium. Lifting height and smallest site occupation and the assemble of bigger components even the whole industrialised house.     

Bioindication and modelling of atmospheric deposition in forests enable exposure and effect monitoring at high spatial density across scales

Key message

Moss surveys provide spatially dense data on environmental concentrations of heavy metals and nitrogen which, together with other biomonitoring and modelling data, can be used for indicating deposition to terrestrial ecosystems and related effects across time and areas of different spatial extension.

Context

For enhancing the spatial resolution of measuring and mapping atmospheric deposition by technical devices and by modelling, moss is used complementarily as bio-monitor.

Aims

This paper investigated whether nitrogen and heavy metal concentrations derived by biomonitoring of atmospheric deposition are statistically meaningful in terms of compliance with minimum sample size across several spatial levels (objective 1), whether this is also true in terms of geostatistical criteria such as spatial auto-correlation and, by this, estimated values for unsampled locations (objective 2) and whether moss indicates atmospheric deposition in a similar way as modelled deposition, tree foliage and natural surface soil at the European and country level, and whether they indicate site-specific variance due to canopy drip (objective 3).

Methods

Data from modelling and biomonitoring atmospheric deposition were statistically analysed by means of minimum sample size calculation, by geostatistics as well as by bivariate correlation analyses and by multivariate correlation analyses using the Classification and Regression Tree approach and the Random Forests method.

Results

It was found that the compliance of measurements with the minimum sample size varies by spatial scale and element measured. For unsampled locations, estimation could be derived. Statistically significant correlations between concentrations of heavy metals and nitrogen in moss and modelled atmospheric deposition, and concentrations in leaves, needles and soil were found. Significant influence of canopy drip on nitrogen concentration in moss was proven.

Conclusion

Moss surveys should complement modelled atmospheric deposition data as well as other biomonitoring approaches and offer a great potential for various terrestrial monitoring programmes dealing with exposure and effects.

     

Micropropagation of Elaeagnus angustifolia from mature trees

Multiple shoots were obtained from nodal segments of mature trees of Elaeagnus angustifolia L. cultured on MS medium (Murashige and Skoog 1962) supplemented with 0, 0.88 or 2.22 micro M N(6)-benzyladenine. When nodal segments taken from the in vitro proliferated shoots were cultured under the same conditions, additional multiple shoots were obtained. Rooting of the in vitro propagated shoots was achieved on full strength MS medium or on MS supplemented with 2.46 micro M indole-3-butyric acid. Regenerated plantlets were acclimatized and successfully transplanted to soil.     

Ozone sensitivity of Phaseolus vulgaris in relation to cultivar differences,growth stage and growing conditions

Exposure of Phaseolus vulgaris cv. Lit to ambient ozone caused a 14% pod yield reduction in 1994. This yield loss was assessed by comparing plants that were protected against ozone by treatment with EDU (ethylenediurea) with unprotected plants, both cultivated in pots with a continuous water supply. The plants had experienced an AOT40 of 8135 ppb.h during their growth. However, plant response to ozone depends on a large number of environmental and plant-specific conditions. Visible injury increased mainly after flowering and was much less severe on soil-grown bean cultivars (Lit, Stella and Groffy) not receiving additional water. Ozone fumigations in closed chambers before or after flowering proved that the growth stage during which the plants are exposed also plays a very important role with regard to injury development. Plants seem to be more susceptible during the generative growth stage and the relative cultivar sensitivity was related to the developmental stage during fumigation. However with regard to yield effects the timing of the ozone exposure seems to be less important.     

堆渣边坡生态棒护坡措施的水土保持效益

[目的]探究堆渣边坡生态棒防护措施的综合防护效果,为露天采石场裸露边坡的生态修复提供依据。[方法]利用人工降雨模拟试验,收集不同降雨强度下地表层和矿渣层的产流量、产沙量,并建立综合贡献度模型。[结果]随着坡度的增加地表层的径流总量和泥沙总量呈递增趋势,而矿渣层的径流总量和泥沙总量呈递减趋势,与径流总量相比泥沙总量变化趋势不明显;对照组与生态棒防护措施下,地表层的产流—产沙相关性均高于矿渣层;当降雨强度为30和120mm/h时,生态棒防护边坡在坡度为15°时具有较佳的防护效果,当降雨强度为60mm/h时,径流量和泥沙量受坡度变化的影响不显著。[结论]生态棒防护措施具有拦蓄坡面径流和泥沙的功能,与对照组相比可以更有效地防治坡面水土流失。