养猪生产中后代性别的预选——发展现状和应用前景     

Detlef Rath  Juah M.Vazquez  吴彩凤 《国外畜牧学(猪与禽)》2007,27(1):31-35

动物精子的性别可通过流式精子分选仪和DNA标识进行鉴定,而利用鉴定性别的精子(即性控精子)并借助人工授精技术或其它授精技术产生的后代,在过去5年中估计已多达30000个(其中大多数是母牛)。有关文献资料证明,能有效地区分X精子和Y精子的唯一标记物是精子染色体中的DNA。众所周知,目前世界各地采用的方法是Beltsville精子分选技术,该技术根据X精子群和Y精子群中DNA相对含量上的差异,用荧光染液(Hoechst33342染液)标记精子,随后利用流式细胞仪分选经荧光标记的精子,从而达到分离精子的目的。目前,X精子或Y精子正常的生产速度是每小时1500万个,该项技术已在家畜、实验动物和动物园动物中应用,如果将该技术应用在人上,在预选后代性别比例上可达90%～95%的成功率。因动物品种不同,性控精子在动物体内的授精部位也不相同。常规的人工授精技术、宫内授精技术、输卵管内授精技术、用于胚胎移植的体外受精(in-vitro fertilization,IVF)技术或子宫角深部授精技术均能有效地使动物怀孕,至于利用哪种技术进行性控精子的精则取决于动物品种。尽管所有动物都能获得高纯度的分选精子,但是在实际生产中利用低剂量精子还难以让母猪怀孕。子宫角深部授精技术每次授精0.5～1.00亿个性控精子已能产生可喜的效果:利用特制的输精管,输入常规人工授精所需精子量的五十分之一的性控精子,足以使动物怀孕。性控精子通过常规的授精技术能够被猪成功利用前,还需重新设计输精管,同时输精的次数和每次授精时精子数量也需作进一步的研究。分选精子的低温保存技术已被牛人工授精普遍采用。尽管已能利用冷冻的性别分选精子生产小猪,但是性别分选精子经冷冻和解冻处理后在常规生产中的应用还未达到最理想的效果。本文将讨论猪精子性别分选的最新研究成果及其发展趋势,并重点探讨将性别分选技术应用于养猪生产中必须对其进行必要的技术开发。  相似文献   

Definition of the principal deficiency, "laryngeal wheeze", based on laryngoscopic mass screening of warm-blooded horses     

E Detlef  H Hell  J Fischer 《Berliner und Münchener tier?rztliche Wochenschrift》1985,98(2):57-60

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Basics of effective erosion control in German agriculture     

Detlef Deumlich  Roger Funk  Monika Frielinghaus  Walter‐Alexander Schmidt  Olaf Nitzsche 《植物养料与土壤学杂志》2006,169(3):370-381

Present research in Germany on water, wind, and tillage erosion is examined. Existing soil‐protection strategies, laws, and guidelines are outlined. These are the result of extensive scientific investigations and the adoption of existing international knowledge. The most common methodologies currently used in Germany are reviewed. They allow an estimation of the water‐ and wind‐erosion risks as well as methods for their reduction. The results enable an aim‐orientated, site‐specific, risk‐adequate approach to implementing control measures in an easily understood framework. The most important remaining research problems are explained.  相似文献   

Behavior of blood pressure, heart rate, hematocrit and serum protein concentration during hyperinfusion therapy in chronic obstructive bronchitis     

E Detlef  L K?hler  G Pieper 《Berliner und Münchener tier?rztliche Wochenschrift》1983,96(3):78-80

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An animal model for interface tissue formation in cemented hip replacements   总被引：2，自引：0，他引：2  

El-Warrak AO  Olmstead M  Apelt D  Deiss F  Noetzli H  Zlinsky K  Hilbe M  Bertschar-Wolfsberger R  Johnson AL  Auer J  von Rechenberg B 《Veterinary surgery : VS》2004,33(5):495-504

OBJECTIVE: To create a model in sheep for investigation of early changes related to the formation of an interface membrane in hip prosthesis. STUDY DESIGN: Experimental study. ANIMALS: Twenty-four female adult Swiss Alpine sheep. METHODS: Sheep were divided into 2 groups of 12 for unilateral cemented total hip arthroplasty. In Group I, the prosthesis was fixed with retrograde cement gun injection to achieve a complete cement mantle, whereas in Group II a primary cement mantle defect was produced. Groups I and II were further divided into 2 sub-groups with study end points of 2 and 8.5 months after surgery. Radiographs were evaluated postoperatively and at euthanasia for migration of the femoral component and bone resorption. Histologic sections were evaluated semiquantitatively for changes in cell types and numbers, and bone reactions; and quantitatively for size of interface membrane and new bone formation. RESULTS: Radiographically, there tended to be an increase in bone resorption and periosteal bone formation throughout the femoral shaft in Group II compared with Group I, but this was only statistically significant at the region of the femoral neck (R5) at both time periods (P<.05). Semiquantitative histologic evaluation revealed significant increases (P<.05) in cellularity, numbers of fibroblasts, giant cells, macrophages, and mononuclear cells, in Group II primarily at 2 months after surgery. This was also true for interface membrane formation and bone remodeling. Quantitative data showed an increased in the size of the interface membrane and area of bone formation at 8.5 months in Group II. CONCLUSIONS: The cement defect model offered controlled and repeatable production of an interface membrane. The results suggest that a primary cement mantle defect could be a possible trigger for implant instability, eliciting a cascade of biomechanical and molecular events in bone tissue leading to aseptic loosening. CLINICAL RELEVANCE: The results show the effect of defects in the cement mantle in promoting interface membrane formation. Long-term and biochemical studies are required to evaluate the relevance of this interface membrane formation.  相似文献   

GFAJ-1 is an arsenate-resistant, phosphate-dependent organism     

TJ Erb  P Kiefer  B Hattendorf  D Günther  JA Vorholt 《Science (New York, N.Y.)》2012,337(6093):467-470

The bacterial isolate GFAJ-1 has been proposed to substitute arsenic for phosphorus to sustain growth. We have shown that GFAJ-1 is able to grow at low phosphate concentrations (1.7 μM), even in the presence of high concentrations of arsenate (40 mM), but lacks the ability to grow in phosphorus-depleted (<0.3 μM), arsenate-containing medium. High-resolution mass spectrometry analyses revealed that phosphorylated central metabolites and phosphorylated nucleic acids predominated. A few arsenylated compounds, including C6 sugar arsenates, were detected in extracts of GFAJ-1, when GFAJ-1 was incubated with arsenate, but further experiments showed they formed abiotically. Inductively coupled plasma mass spectrometry confirmed the presence of phosphorus in nucleic acid extracts, while arsenic could not be detected and was below 1 per mil relative to phosphorus. Taken together, we conclude that GFAJ-1 is an arsenate-resistant, but still a phosphate-dependent, bacterium.  相似文献   

SURVIS: a fully-automated aerial baiting system for the distribution of vaccine baits for wildlife     

Müller T  Freuling CM  Gschwendner P  Holzhofer E  Mürke H  Rüdiger H  Schuster P  Klöss D  Staubach C  Teske K  Vos A 《Berliner und Münchener tier?rztliche Wochenschrift》2012,125(5-6):197-202

Large-scale oral vaccination of wildlife against rabies using aerial bait distribution has been successfully used to control terrestrial wildlife rabies in Europe and North America. A technical milestone to large-scale oral rabies vaccination campaigns in Europe was the development of fully-automated, computer-supported and cost-efficient technology for aerial distribution of baits like the SURVIS -system. Each bait released is recorded by the control unit through a sensor, with the exact location, time and date of release and subsequently the collected data can be evaluated, e.g. in GIS programmes. Thus, bait delivery systems like SURVIS are an important management tool for flight services and the responsible authorities for the optimization and evaluation of oral vaccination campaigns of wildlife against rabies or the control of other relevant wildlife diseases targeted by oral baits.  相似文献   

Phosphorus and iron erosion from non-vegetated sites in a post-mining landscape,Lusatia, Germany: Impact on aborning mining lakes     

Andreas Kleeberg  Andrea Schapp  Detlef Biemelt 《CATENA》2008

Particulate phosphorus (P) can be transported via soil erosion in overland flow to waters, where it provides a long-term source of P for aquatic biota, and can accelerate freshwater eutrophication. Hence, knowledge of P sources is important for good environmental management. However, data on P, and related Fe, losses from various structures of a post-mining landscape are lacking. A year-long monitoring, and ten short rainfall simulations on plot scale, at ridges and rills and a combination of them, revealed high erosion from bare lignite mining dumps at Schlabendorf-North, Lusatia, Germany. The mean annual soil erosion rate from the year-long monitoring site was 18 × 10⁶ kg km^− 2 yr^− 1, corresponding to 0.034 g m^− 2 min^− 1. The erosion rates were lowest at rill plots (1.9–4.4 g m^− 2 min^− 1), intermediate at ridge plots (14.3–37.1 g m^− 2 min^− 1), and highest at a combined rill and ridge plot (48.7–63.4 g m^− 2 min^− 1). These differences in extent were due to small scale differences in morphology and extreme water repellency. The hydrophobicity leads to very low infiltration, thus generating surface runoff even at low rainfall intensities. Loss rates of P and Fe, as deduced from the year-long erosion rate, were 470–650 kg km^− 2 yr^− 1, and 37.9 × 10³–71 × 10³ kg km^− 2 yr^− 1 respectively. However, these P inputs from lignite mining dump erosion, consisting of P-poor (17–90 μg g^− 1) tertiary spoil materials, into aborning mining lakes, are negligible since they are accompanied by high Fe inputs, which favour an efficient P co-precipitation in the water column.  相似文献   

Bodenphysikalische Bewertung der Kompostwirkung durch Laboruntersuchungen     

Waltraut Richter  Detlef Laves  Lothar Suntheim 《植物养料与土壤学杂志》2002,165(1):79-81

<?show $38#Bo;>Soil physical evaluation of the efficiency of addition of composts to soils by laboratory experiments Additionally to long‐term field experiments a laboratory method was tested for evaluation the physical efficiency of addition of composts to soil. The parameters maximal water holding capacity (MWK), bulk density (TRD), and total pore volume (PV) were determined under reproducible conditions for compost‐soil‐mixtures in comparison to equivalent mixtures of soil with standard‐peat‐litter. The ratio of the coefficients of regression for compost‐soil‐mixtures to those for standard‐peat‐litter‐soil‐mixtures is the so‐called equivalent of standard‐peat‐litter (TMÄ). The efficiency of changes of soil physical properties due to the addition of compost to soil is characterized by TMÄ.<?show $6#>  相似文献   

Strategy of statistical model selection for precision farming on-farm experiments   总被引：2，自引：0，他引：2  

Heinrich Thöle  Christel Richter  Detlef Ehlert 《Precision Agriculture》2013,14(4):434-449

Nitrogen (N) fertilization implies two important issues: N enhances grain yields and quality, but applied in excess, nitrous oxide emissions and nitrate leaching may be induced. To reduce environmental impacts, spatial N variability in agricultural fields can be adapted using crop sensors. In on-farm experiments, sensor-based variable rate N application is compared to uniform N application, which is common agricultural practice. On-farm experiments (OFE) provide special considerations as opposed to on-station trials. In OFE, the experimental units in farmer-managed fields are considerably larger, which raises the question if soil heterogeneity may be fully controlled by the experimental design (random treatment allocation and blocking). Grain yield monitoring systems are used increasingly in OFE and provide spatially correlated data. As a consequence, classical analysis of variance is not a valid option. An alternative four-step strategy of statistical model selection is presented, generalizing the assumptions of classical analysis of variance within the framework of linear mixed models. Soil heterogeneity is preliminary identified in step 1 and finalized in step 2 using covariate combinations (analysis of covariance). Yield data correlations are handled in step 3 using geo-statistical models. The last step estimates treatment effects and derives the statistical inference. Analyses of three OFE revealed that different covariate combinations and geo-statistical models were needed for each trial, which involves higher analytical efforts than for on-station trials. These efforts can be minimized by following the steps provided in this study to find a best model approximation. Nevertheless, model selection in precision farming OFE will always accompany some uncertainty.  相似文献