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11.
Hans Eckert Gerhard Breitschuh Manfred Kerschberger 《Archives of Agronomy and Soil Science》2013,59(3):165-177
Repräsentative ostdeutsche Landwirtschaftsbetriebe sind hinsichtlich ihrer Umweltverträglichkeit bewertet worden. Dazu diente eine Methode, die für ca. 30 relevante Umwelt‐Gefährdungspotentiale aus den Bereichen Düngung, Bodenschutz, Pflanzenschutzmitteleinsatz, Agrarraumgestaltung, Artendiversität, Energiebilanz und Tierbesatz kritische Umweltbelastungen formuliert und damit aktuelle Betriebsdaten wertend vergleicht. Die Ergebnisse zeigen eine sehr differenzierte Situation. Während Stoffbelastungen mit Konsequenzen für die Nahrungsqualität weitgehend unkritisch sind, bestehen Defizite vor allem als “Altlasten”; in den Bereichen Bodenschutz und Agrarraumgestaltung. Beziehungen zwischen Intensität und Umweltverträglichkeitsbewertung werden diskutiert. 相似文献
12.
The purpose of this study was to determine the cardiovascular effects of sodium nitroprusside (SNP)‐induced after load reduction in dogs administered dexmedetomidine (DEX). Using a randomized crossover design and allowing at least 2 weeks between treatments 12 adult hound dogs of either sex weighing 22 ± 1.7 SD kg were anesthetized by face mask administration of 2.9% ET sevoflurane to facilitate instrumentation prior to administration of treatment drugs. Dogs were intubated and instrumented to enable measurement of heart rate (HR), systolic (SAP), mean (MAP) and diastolic (DAP) arterial pressures, mean pulmonary arterial pressure (PAP), pulmonary capillary wedge pressure (PCWP), central venous pressure (CVP), pulmonary arterial temperature (TEMP), and cardiac output (CO). Systemic (SVR) and pulmonary vascular resistances were calculated. Following completion of instrumentation dogs were allowed to recover for 40 minutes. After collection of baseline data, dogs were administered one of four treatments at T–10 minutes prior to injection of DEX (500? g M–2 IM): 1) saline (SAL); 2) atropine (ATR, 0.02 [n = 6] or 0.04 [n = 6] mg kg–1 IM); 3) SAL + SNP (infused at 1–10 ?g kg–1 minute–1, IV as needed to maintain MAP between 90–110 mm Hg; or 4) ATR + SNP. Cardiovascular data were collected at T‐20 minutes prior to administration of DEX, T‐5 and at 5, 10, 20, 30, 40, and 60 minutes following DEX. Data were analyzed using anova for repeated measures with post hoc differences between means identified using Bonferroni's method (p < 0.05). Differences in ATR dose were not found to be significant and thus results for ATR dose groups were pooled. Administration of SAL (dexmedetomidine alone) was associated with decreases in HR and CO and increases in SAP, MAP, DAP, CVP, and SVR. Administration of ATR was associated with an increase in HR and CO compared with SAL. Administration of SNP was associated with an increase in HR and CO and a decrease in SVR, MAP and CVP compared with SAL. Administration of SNP + ATR was associated with effects similar to that of SNP or ATR alone and resulted in an additive increase in CO. We conclude that SNP‐induced afterload reduction with or without atropine is effective in mitigating DEX‐induced impairment of cardiovascular function. 相似文献
13.
Variation in clinical and parasitological traits in Pietrain and Meishan pigs infected with Sarcocystis miescheriana 总被引:1,自引:0,他引:1
Reiner G Eckert J Peischl T Bochert S Jäkel T Mackenstedt U Joachim A Daugschies A Geldermann H 《Veterinary parasitology》2002,106(2):99-113
Future prophylaxis needs new concepts, including natural disease resistance of hosts against infectious agents. Genomic approaches to detect and improve disease resistance in farm animals and the molecular mechanisms involved in host-parasite interactions depend to a high degree on the trait differences between founder breeds, i.e. on the animal model. The present study evaluates differences in susceptibility/resistance against Sarcocystis miescheriana in the European Pietrain (PI) and the Chinese Meishan (ME) pig breeds, based on 25 individuals, infected orally with 5x10(4) sporocysts of S. miescheriana. Significant differences appeared in clinical, serological, haematological and parasitological findings. The major discriminating period post infection (p.i.) was between days 42 and 45. Severity of signs was negatively correlated with specific immunoglobulin titres during the first 3 weeks p.i. and positively with the load of bradyzoites in muscle tissues of the pigs. Loads of bradyzoites in muscle tissues were 20 times higher in PI than in ME. Sarcocystis-specific differences between the two breeds were in the range of 1-2 standard deviations. The study lays the foundation for further experiments to analyse chromosomal regions, candidate genes, and thus the molecular basis of Sarcocystis susceptibility/resistance as a model for host-parasite interaction in protozoan infectious disease. 相似文献
14.
In this paper, we discuss the advantages and disadvantages of various approaches of teaching veterinary parasitology, including the disciplinary, the problem-oriented and combined approaches. In the disciplinary approach, parasitology is taught in the classical manner as a coherent subject, covering parasite morphology, biology, molecular biology, epidemiology, pathology, immunology, clinical manifestation, diagnosis, therapy, control, and prevention. Problem-oriented teaching approaches the subjects starting from diseases in animal species or from organ systems or other objectives (e.g. food safety); it also tackles training of skills for problem solving and self-learning. Combined approaches include elements of the disciplinary approach and those of other methods. A combined approach of teaching veterinary parasitology, including basic disciplinary teaching of at least 70-90 h, and additional problem-oriented education, was recently proposed in a resolution by the World Association for the Advancement of Veterinary Parasitology [WAAVP News Lett. 5 (1) 3-4]. In 1999, a new curriculum has been established at the Faculty of Veterinary Medicine, University of Berne, originally planned as a combination of organ-focused and problem-based approach. This model was soon identified to cause problems in teaching some disciplines, including infectious diseases. Conversely, the short-term experiences with this combined approach also confirmed some advantages of problem-oriented teaching in other, mainly clinical domains. Nevertheless, closer interdisciplinary contact and collaboration--especially in elective teaching--was enforced between paraclinical and clinical teaching by reforming the curriculum. However, it turned out that large student numbers in relation to the resources of manpower, rooms and finances limited the workability of the curriculum. Therefore, further and probably continuous improvement of the curriculum is necessary. 相似文献
15.
采用免疫组织化学方法对不同日龄的长爪沙鼠颌下腺IgA的定位分布进行了研究。结果表明,长爪沙鼠的颌下腺由导管部和分泌部构成,分泌部主要由浆液腺构成,导管部包括闰管、纹管、颗粒曲管和小叶间导管等。DAB显色结果表明,IgA阳性细胞主要分布于浆液性腺泡、闰管、纹管、颗粒曲管和小叶间导管,并可分布于腺泡和腺管间结缔组织,IgA阳性产物的分布具有不均一性,无明显随年龄变化的规律性。阳性产物分布于胞质中,胞核呈阴性,对照组阴性。提示从浆细胞产生或循环而来的IgA先经结缔组织进入颌下腺组织,进而定位分布于浆液腺泡和各级导管,导管部有较多的IgA分布。 相似文献
16.
四翅滨藜全光照喷雾嫩枝扦插试验结果表明:采用NAA、ABT 2号生根粉、IBA等3种外源植物生长调节剂处理插条2 h,对插条具有良好的促根作用,其中100 mg/L NAA为最好,生根率可达到93.6%;100 mg/LABT2号生根粉和100 mg/L IBA次之,生根率分别可以达到92.6%,92.3%. 相似文献
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19.
土壤活性有机碳能够准确反映土壤有效性,表征土壤质量变化,是探索可持续草地管理措施的关键指标之一。以内蒙古贝加尔针茅草原为研究对象,采用围封、放牧和刈割野外控制试验,探讨不同利用方式对土壤有机碳(SOC)和活性有机碳的影响,发现不同利用方式下土壤SOC含量表现为围封>刈割>放牧,其中围封区和刈割区土壤SOC含量显著大于放牧区,围封区与刈割区土壤SOC含量差异不显著,在土壤活性有机碳中土壤可溶性有机碳(DOC)含量表现为放牧>围封>刈割。土壤微生物量碳(MBC)和土壤易氧化有机碳(ROC)含量均表现为围封>刈割>放牧,围封区与刈割区土壤MBC和土壤ROC平均含量差异不显著,且均显著大于放牧区。土壤MBC、ROC和SOC之间呈极显著相关性(P<0.01)。土壤ROC和土壤MBC与土壤全氮和土壤全磷呈极显著相关性(P<0.01)。围封与刈割有利于土壤SOC、MBC、ROC的提升,放牧对土壤DOC有一定累积作用。围封和刈割增强了土壤SOC的稳定性,活性有机碳与土壤有机碳和土壤理化性质密切相关,能够敏感地反映土壤有机碳的变化。 相似文献
20.
基于EDA技术的自动立木整枝机无线遥控发射系统 总被引:4,自引:0,他引:4
立木整枝是优质工业用材林定向抚育的重要环节,采用自动立木整枝机是实现高效、高质量和安全可靠整枝的有效途径。本文综合运用电子电路设计及优化技术、无线遥控及通信编解码技术,创造性地研制了基于CPLD的无线数字编码抗干扰自动立木整枝机无线遥控发射系统,通过优化CPLD内部逻辑电路有效消除了逻辑竞争冒险、降低了噪声干扰,确保了系统逻辑设计的正确性。该系统具有可靠、节能、抗干扰、工作效率高等优点。本研究成果及方法为推进其他林业机械的自动化与智能化进程提供了一种有效的新思路。 相似文献