Zuordnung des Munsell‐Codes zu einem Farbnamen nach bodenkundlichen Kriterien     

Christoph Albrecht  Bernd Huwe  Reinhold Jahn 《植物养料与土壤学杂志》2004,167(1):60-65

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Review of ground-based methods to measure the distribution of biomass in forest canopies   总被引：1，自引：0，他引：1  

Dominik Seidel  Stefan Fleck  Christoph Leuschner  Tom Hammett 《Annals of Forest Science》2011,68(2):225-244

? Context

Ecological research and an effective forest management need accurate information on the structure of the forest canopy to understand the biochemical, physiological and biogeochemical processes within a forest.

? Research question

This paper reviews the currently available instruments for measuring the distribution of biomass within forest canopies. We compare the most well-established approaches and present the different measurable parameters. A special focus lies on the resolution of the obtained data.

? Results

It was found that only 3D laser scanners offer data with the resolution required by ecologists, private landholders, the forest industry and the public to detect trends in tree growth patterns and canopy interactions in all three spatial dimensions. But data validation, data analysis and parameter extraction are still under development, and the price of the instrument is quite high.

? Conclusion

Research should focus on the parameter extraction from terrestrial laser scanner data as this could allow the calculation of functional attributes for different sections of a canopy on a high spatial resolution. It could also help ecologists characterize the structure of forest stands in a quick and precise way.  相似文献   

Transfer of veterinary drugs and pharmacologically-active feed additives into soil with special consideration of tetracyclines – executive summary     

Christoph Winckler  Alexander Grafe 《Journal of Soils and Sediments》2001,1(1):58-62

Conclusions  

–	•In intensive animal production, a considerable proportion of the livestock population must be expected to receive animal pharmaceuticals.
–	•The administration of pharmacologically-active feed additives has been influenced through the revocation of approval for some individual substances over the last few years. Aside from the substitution of these forbidden substances, further reductions in the use of antibiotic growth promotors can be expected primarily because of economic reasons.
–	•Animal pharmaceuticals frequently consist of so-called older preparations whose ecotoxicological potentials have only been investigated inadequately.
–	•High elimination rates of the active substances and their stability during storage, which could be demonstrated for tetracyclines, might also lead to a significant incorporation of these substances into the soil even when they are employed correctly. In the future, ecotoxicological investigations should be demanded in cases where the EMEA/CVMP trigger values (which are substantially lower) have been exceeded, a procedure which is currently only required for the newly approved agents.
–	•There is presently a considerable need for research into the environmental fate of these older preparations and their ecotoxicological effects. Here, it will be especially important to take the degradation and transformation processes in the soil into account, as well as especially considering the consequences on the microbiological impacts affecting the soil.
–	•Improved transparency in the application of these substances, in the sense of a quantitative’registration of the animal pharmaceuticals (especially the older preparations) which are employed, as well as the environmental monitoring of animal pharmaceuticals (e.g. in groundwater and surface water), would considerably improve the significance of the basic data for future appraisals.

German federal research plan from the German Federal Ministry for the Environment, Wildlife Conservation and Nuclear Safety - Treatment and utilization of wastes. Research report 297 33 911 - UBA-FB 000074. Original title: Charakterisierung und Verwertung von Abf?llen aus der Massentierhaltung unter Berücksichtigung verschiedener B?den. Stoffeintrag in B?den durch Tierarzneimittel und pharmakologisch wirksame Futterzusatzstoffe unter besonderer Berücksichtigung von Tetrazyklinen. A research article on this topic follows in JSS No. 2. DOI: http://dx.doi.org/10.1065/jss2001.02.006. By courtesy of the German Federal Environmental Agency (Umweltbundesamt - UBA). The complete research report is available as UBA-TEXTE 44/00 (ISSN 0722-186X) by payment of DM 20,00 (Euro 10,26), account no. 4327 65-104, Postbank Berlin (BLZ 10010010), Fa. Werbung und Vertrieb, Ahornstra?e 1-2, D-10787 Berlin, Germany  相似文献   

Improving the health of the global poor     

Jha P  Mills A  Hanson K  Kumaranayake L  Conteh L  Kurowski C  Nguyen SN  Cruz VO  Ranson K  Vaz LM  Yu S  Morton O  Sachs JD 《Science (New York, N.Y.)》2002,295(5562):2036-2039

We analyzed the technical basis for a major global program to reduce disease among the poor. Effective interventions exist against the few diseases which most account for excess mortality among the poor. Achieving high coverage of effective interventions requires a well-functioning health system, as well as overcoming a set of financial and nonfinancial constraints. The annual incremental cost would be between $40 billion and $52 billion by 2015 in 83 low-income and sub-Saharan African countries. Such a program is feasible and would avoid millions of child, maternal, and adult deaths annually in poor countries.  相似文献   

Cancer. An unstable liaison     

Lengauer C 《Science (New York, N.Y.)》2003,300(5618):442-443

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Amplification of acetylcholine-binding catenanes from dynamic combinatorial libraries     

Lam RT  Belenguer A  Roberts SL  Naumann C  Jarrosson T  Otto S  Sanders JK 《Science (New York, N.Y.)》2005,308(5722):667-669

Directed chemical synthesis can produce a vast range of molecular structures, but the intended product must be known at the outset. In contrast, evolution in nature can lead to efficient receptors and catalysts whose structures defy prediction. To access such unpredictable structures, we prepared dynamic combinatorial libraries in which reversibly binding building blocks assemble around a receptor target. We selected for an acetylcholine receptor by adding the neurotransmitter to solutions of dipeptide hydrazones [proline-phenylalanine or proline-(cyclohexyl)alanine], which reversibly combine through hydrazone linkages. At thermodynamic equilibrium, the dominant receptor structure was an elaborate [2]-catenane consisting of two interlocked macrocyclic trimers. This complex receptor with a 100 nM affinity for acetylcholine could be isolated on a preparative scale in 67% yield.  相似文献   

Comment on "On the origin of interictal activity in human temporal lobe epilepsy in vitro"     

Wozny C  Kivi A  Lehmann TN  Dehnicke C  Heinemann U  Behr J 《Science (New York, N.Y.)》2003,301(5632):463; author reply 463

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Quantum spin hall insulator state in HgTe quantum wells   总被引：1，自引：0，他引：1  

König M  Wiedmann S  Brüne C  Roth A  Buhmann H  Molenkamp LW  Qi XL  Zhang SC 《Science (New York, N.Y.)》2007,318(5851):766-770

Recent theory predicted that the quantum spin Hall effect, a fundamentally new quantum state of matter that exists at zero external magnetic field, may be realized in HgTe/(Hg,Cd)Te quantum wells. We fabricated such sample structures with low density and high mobility in which we could tune, through an external gate voltage, the carrier conduction from n-type to p-type, passing through an insulating regime. For thin quantum wells with well width d < 6.3 nanometers, the insulating regime showed the conventional behavior of vanishingly small conductance at low temperature. However, for thicker quantum wells (d > 6.3 nanometers), the nominally insulating regime showed a plateau of residual conductance close to 2e(2)/h, where e is the electron charge and h is Planck's constant. The residual conductance was independent of the sample width, indicating that it is caused by edge states. Furthermore, the residual conductance was destroyed by a small external magnetic field. The quantum phase transition at the critical thickness, d = 6.3 nanometers, was also independently determined from the magnetic field-induced insulator-to-metal transition. These observations provide experimental evidence of the quantum spin Hall effect.  相似文献   

Glutamatergic and dopaminergic neurons mediate anxiogenic and anxiolytic effects of CRHR1     

Refojo D  Schweizer M  Kuehne C  Ehrenberg S  Thoeringer C  Vogl AM  Dedic N  Schumacher M  von Wolff G  Avrabos C  Touma C  Engblom D  Schütz G  Nave KA  Eder M  Wotjak CT  Sillaber I  Holsboer F  Wurst W  Deussing JM 《Science (New York, N.Y.)》2011,333(6051):1903-1907

The corticotropin-releasing hormone receptor 1 (CRHR1) critically controls behavioral adaptation to stress and is causally linked to emotional disorders. Using neurochemical and genetic tools, we determined that CRHR1 is expressed in forebrain glutamatergic and γ-aminobutyric acid-containing (GABAergic) neurons as well as in midbrain dopaminergic neurons. Via specific CRHR1 deletions in glutamatergic, GABAergic, dopaminergic, and serotonergic cells, we found that the lack of CRHR1 in forebrain glutamatergic circuits reduces anxiety and impairs neurotransmission in the amygdala and hippocampus. Selective deletion of CRHR1 in midbrain dopaminergic neurons increases anxiety-like behavior and reduces dopamine release in the prefrontal cortex. These results define a bidirectional model for the role of CRHR1 in anxiety and suggest that an imbalance between CRHR1-controlled anxiogenic glutamatergic and anxiolytic dopaminergic systems might lead to emotional disorders.  相似文献   

Relating genetic variation of ecologically important tree traits to associated organisms in full-sib aspen families     

Frauke Kleemann  Maximilian von Fragstein  Barbara Vornam  Annika Müller  Christoph Leuschner  Andrea Holzschuh  Teja Tscharntke  Reiner Finkeldey  Andrea Polle 《European Journal of Forest Research》2011,130(5):707-716

Knowledge on phenological, morphometric, and phytochemical variation of local progenies of European aspen (Populus tremula, L.) is limited. The goal of this study was to characterize variation in growth and ecologically important leaf properties in aspen full-sib families in relation to interacting organisms (mycorrhiza, endophytes, and insects) and to determine whether these interactions were affected by soil application of a systemic fungicide. In local progenies, within-family variation of neutral molecular genetic markers (nuclear microsatellites) was higher than between families. Significant variation in growth, production of phenolic defensive compounds and other phytochemical leaf traits was found between families. Phenolic compounds showed clear negative correlation with generalist herbivores, but did not result in negative trade-off with biomass production. Differences in mycorrhizal colonization were not found among full-sib families and application of a systemic fungicide suppressed neither mycorrhizal colonization nor infestation with insects. However, a strong suppression of endophytes occurred, whose long-term consequences may require attention when fungicides are used in agroforestry plantations.  相似文献