Schwermetallgehalte in landwirtschaftlich relevanten stoffen     

Manfred Kerschberger  Günther Franke  Werner Schuricht 《Archives of Agronomy and Soil Science》2013,59(1-2):147-164

Die Gehalte für die sechs Schwermetalle Cd, Cr, Cu, Ni, Pb und Zn in landwirtschaftlich relevanten Stoffgruppen (mineralische und organische Düngestoffe, Kulturpflanzen und tierische Produkte) wurden aus Literaturdaten für die beiden statistischen Maßzahlen Mittelwert und Spannweite der Mittelwerte in Übersichtstabellen zusammengefasst.  相似文献   

Mycosporine-like amino acids and marine toxins--the common and the different          下载免费PDF全文

Klisch M  Häder DP 《Marine drugs》2008,6(2):147-163

Marine microorganisms harbor a multitude of secondary metabolites. Among these are toxins of different chemical classes as well as the UV-protective mycosporine-like amino acids (MAAs). The latter form a group of water-soluble, low molecular-weight (generally < 400) compounds composed of either an aminocyclohexenone or an aminocyclohexenimine ring, carrying amino acid or amino alcohol substituents. So far there has been no report of toxicity in MAAs but nevertheless there are some features they have in common with marine toxins. Among the organisms producing MAAs are cyanobacteria, dinoflagellates and diatoms that also synthesize toxins. As in cyclic peptide toxins found in cyanobacteria, amino acids are the main building blocks of MAAs. Both, MAAs and some marine toxins are transferred to other organisms e.g. via the food chains, and chemical modifications can take place in secondary consumers. In contrast to algal toxins, the physiological role of MAAs is clearly the protection from harmful UV radiation by physical screening. However, other roles, e.g. as osmolytes and antioxidants, are also considered. In this paper the common characteristics of MAAs and marine toxins are discussed as well as the differences.  相似文献   

Early pathogen detection under different water status and the assessment of spray application in vineyards through the use of thermal imagery   总被引：3，自引：0，他引：3  

Manfred Stoll  Hans R. Schultz  Gerhard Baecker  Beate Berkelmann-Loehnertz 《Precision Agriculture》2008,9(6):407-417

Remote detection using thermal imagery has potential for use in the pre-symptomatic diagnosis of abiotic stress or of early disease detection. The latter is an issue of great importance since late detection of fungus attacks or poor spray coverage are major factors contributing to weak disease control affecting fruit quality or reducing yield in grapes. In greenhouse experiments the effects on spatial and temporal variability of leaf temperature of grapevine (Vitis vinifera L. cv. Riesling) leaves inoculated with a fungal pathogen (Plasmopara viticola (Berk. & Curt. Ex de Bary) were studied in either well-irrigated or non-irrigated potted plants. Due to the high sensitivity of leaf temperature to the amount of water transpired, infra-red thermography can be used to monitor irregularities in temperature at an early stage of pathogen development. Evidence for characteristic thermal responses in grapevines was apparent well before visible symptoms appeared. Contrasting thermal effects due to the pathogen attack were found between measurements on well-irrigated and water-stressed plants. Furthermore, from a technical point of view, thermal imagery has the potential to assess the evenness of spray coverage within a canopy, hence optimizing pesticide application efficiency.  相似文献   

Genetic and phenotypic parameters for monthly egg production in White Leghorn hens   总被引：1，自引：0，他引：1  

A. Anang  N. Mielenz  L. Schüler 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2000,117(6):407-415

This article reports genetic and phenotypic parameters of monthly egg production and the influence of Box‐Cox transformation on the parameters from a population of White Leghorns, selected for feed efficiency. A total of 6450 daughters of 180 sires and 1335 dams were analysed by restricted maximum likelihood (REML) using a multivariate animal model. The traits considered were monthly egg productions, cumulative production of the first 5 months (S5), cumulative production of first 10 months (S10), and survivor egg production in the first cycle (S12). Two sets of data were analysed: the original data and with the Box‐Cox method transformed data. The results indicated that there were no great differences in the estimates between untransformed and transformed data. The estimates of heritability for monthly egg production were high for the first period, decreased to reach the lowest during peak production, and increased to the end of lay. The estimates of heritability for cumulative records were generally higher than monthly records. Genetic and phenotypic correlations among monthly egg production totals were generally high for contiguous periods and then decreased as the interval between months increased. The highest genetic correlation between monthly records and S5 was for the second month of production, whereas the correlations between monthly production totals and S10 and S12 reached their peak at the sixth and eighth months of production, respectively.  相似文献   

Simultaneous flowering of umbrella bamboo （Fargesia murieliae） at its native home in Central China   总被引：1，自引：0，他引：1  

Manfred DENICH  Thomas BORSCH 《林业研究》2006,17(4):293-297

Introduction The life history of many bamboo species is characterized by an unusual flowering habit. They often flower and die simultaneously over wide areas at long intervals (3–120 years), and then regenerate from seed or rhizome (Janzen 1976; Liese 19…  相似文献   

Why implantation of bio‐loggers may improve our understanding of how animals cope within their natural environment     

Marie‐Amlie FORIN‐WIART  Manfred R. ENSTIPP  Yvon LE MAHO  Yves HANDRICH 《Integrative zoology》2019,14(1):48-64

Bio‐loggers are miniaturized autonomous devices that record quantitative data on the state of free‐ranging animals (e.g. behavior, position and physiology) and their natural environment. This is especially relevant for species where direct visual observation is difficult or impossible. Today, ongoing technical development allows the monitoring of numerous parameters in an increasing range of species over extended periods. However, the external attachment of devices might affect various aspects of animal performance (energetics, thermoregulation, foraging as well as social and reproductive behavior), which ultimately affect fitness. External attachment might also increase entanglement risk and the conspicuousness of animals, leaving them more vulnerable to predation. By contrast, implantation of devices can mitigate many of these undesirable effects and might be preferable, especially for long‐term studies, provided that the many challenges associated with surgical procedures can be mastered. Implantation may then allow us to gather data that would be impossible to obtain otherwise and thereby may provide new and ecologically relevant insights into the life of wild animals. Here, we: (i) discuss the pros and cons of attachment methods; (ii) highlight recent field studies that used implanted bio‐loggers to address eco‐physiological questions in a wide range of species; and (iii) discuss logger implantation in light of ethical considerations.  相似文献   

Growth behavior of Phyllostachys nigra var. henonis （Bambusoideae） in Central China     

Li Zhao-hua  Manfred Denich  Thomas Borsch 《林业研究》2005,16(3):163-168

In the Shennongjia National Nature Reserve of Central China, the vegetative growth behavior of henon bamboo (Phyllostachys nigra var.henonis (Mitford) Stapf. ex Rendle) was studied from shoot recruitment to culm establishment. In May, bamboo shoots emerging from the ground achieved an average density of 2.7 shoots m⁻² during the sprouting phase of 16 days. However, about 32% of the new shoots died back before maturity. Insect damage, withering death and rodent predation were responsible for 57%, 29% and 14% of the total shoot mortality, respectively. From May to June, the shoots attained 400±23 cm during the height growth phase of 34 days, with a daily rate varying from 1 to 56 cm. All branches and leaves unfolded during the branch spreading phase from June to August. Shoot production was positively related to the density of standing culms, but negatively to both coverage and height of herb layers. Foundation item: This research was financed by the Center for Development Research (ZEF) of the University of Bonn, Germany (P. 52015), the National Natural Science Foundation of China (No. 30470284) and the Scientific Research Foundation for the Returned Overseas Chinese Scholars (No. 2004-527). Biography: Li Zhao-hua (1964-), male, Doctoral of Natural Science (Bonn University), Professor of Ecology (Hubei University, Wuhan 430062, P. R. China). Responsible editor: Chai Ruihai  相似文献   

Die schwedische Reichswaldtaxation     

Manfred Näslund 《European Journal of Forest Research》1957,76(11-12):321-333

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Effects of Bamboo Fargesia murielae on Plant Diversity in Fir Forest on Mountain Shennongjia   总被引：3，自引：0，他引：3  

LiZhaohua ManfredDenich ThomasBorsch 《中国林学(英文版)》2004,6(4):17-22

Simultaneous flowering caused a gregarious dieback of umbrella bamboo (Fargesia murielae) all over the world in 1993-2000. Mountain Shennongjia in Central China‘s Hubei Province is the only native home of umbrella bamboo, where it dominates the understorey of the farges fir (Abiesfargesii) forest between 2 400 and 3 100 m, covering the ground for more than one century before a periodically flowering death. Data from 20 quadrats along a vegetation sequence revealed that the density, coverage,and height of umbrella bamboo negatively affected the species richness, diversity, and evenness of vascular plants in the forest. Local climax community of fir-bamboo was the poorest in species diversity, while the bamboo-free communities (i.e. shrubs and meadows)were bearing a higher species diversity. The simultaneous dieback of umbrella bamboo is an ecological relcase, which can pcriodically promote the plant diversity in the fir forest.  相似文献   

Penetration studies of propoxur and phoxim from eggshell into whole egg after experimental exposure and application in henhouses     

Limsuwan S  Priess B  Tansakul N  Nau H  Kietzmann M  Hamscher G 《Journal of agricultural and food chemistry》2007,55(15):6401-6405

The penetration of propoxur and phoxim from eggshell into whole egg was investigated in vitro by spraying eggs directly and in vivo after application of the compounds in henhouses. Although mean concentrations of the compounds on eggshells were up to 23000 microg kg(-1), mean residue concentrations in whole eggs were far below the current maximum residue levels (50 microg kg(-1) for propoxur and 60 microg kg(-1) for phoxim). These results provide the first evidence that propoxur and phoxim do not penetrate from eggshell into whole egg under experimental and field conditions. Subsequently, residue carry-over after egg cracking in households and during a worst-case situation in an egg-cracking plant was investigated. However, when eggs were cracked manually, a negligible contamination of whole egg values occurred. If, in an automated process, eggshells accidentally come into close contact with whole egg, very high residue levels of propoxur and phoxim may be generated time dependently. These results suggest that eggshell contact with whole egg during egg cracking must be avoided to prevent pesticide carry-over.  相似文献