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51. The Earth Scope Data Portal

Author

Memon, A., Baru, C., Behrens, K., Casey, R., Hoyt, B., Kamb, L., Lin, K., Weertman, B., and Weiland, C.

Published
2008

57. [Commerce interrégional et international : soixante dix ans après Ohlin]

Author

Behrens, K., Gaigné, Carl, Ottaviano, G., Thisse, J.F., Inconnu, Centre d'Economie et de Sociologie Rurales Appliquées à l'Agriculture et aux Espaces Ruraux (CESAER ), Institut National de la Recherche Agronomique (INRA), and EXT

Subjects
économie du bien-être, [SDV]Life Sciences [q-bio], espace et société, Environnement
Abstract

Les auteurs analysent l'impact de la baisse des coûts de transport international et infranational sur la géographie économique des pays ainsi que sur les termes des échanges et le bien-être. Cette analyse est menée à partir d'un cadre théorique qui diffère significativement de ce qui a été accompli jusqu'ici. Les auteurs considèrent que les travailleurs sont mobiles géographiquement entre les régions au sein d'un même pays, mais sont immobiles entre les pays. Ensuite, l'échange de biens est supposé coûteux et possible entre les pays et entre les régions. Enfin, dans leur modèle, les coûts de transport interrégionaux et internationaux ont un impact direct sur la formation des prix et des salaires.

Published
2003

58. Grade control of ores: how different X-ray fluorescence technologies deliver accuracy and precision in daily routine.

Author

Behrens K., Iron ore conference Perth, Western Australia 12-Aug-1314-Aug-13, Grigolato E., Porta D., Behrens K., Iron ore conference Perth, Western Australia 12-Aug-1314-Aug-13, Grigolato E., and Porta D.

Abstract

Low-grade ores with frequent mineralogy changes make the set-up and maintenance of analytical strategies in the mining laboratory more difficult. Early knowledge about contamination from ores will help producers to avoid high levels for example of Cd or Pb in their final metal alloys, enforcing a higher degree of analytical flexibility. X-ray fluorescence (XRF) analysis is known for the very short time to result, the high level of accuracy and precision, and the simple sample preparation paired with a high degree of automation, making XRF the best suited analytical method for process and grade control in mining operations. Simultaneous wavelength-dispersive XRF (WDXRF) instruments are delivering accuracy paired with precision in the shortest possible measurement time. A new instrument design combines the analytical performance of the conventional configuration with fixed wavelength-dispersive element channels and a modern simultaneous energy-dispersive detector in order to achieve high analytical precision and accuracy. At the same time, whereas the elements of interest are counted with fixed channels the energy-dispersive detector records the complete spectrum of the sample. This snap-shot of the elemental composition enables all elements present in the sample to be monitored without adding additional measurement time., Low-grade ores with frequent mineralogy changes make the set-up and maintenance of analytical strategies in the mining laboratory more difficult. Early knowledge about contamination from ores will help producers to avoid high levels for example of Cd or Pb in their final metal alloys, enforcing a higher degree of analytical flexibility. X-ray fluorescence (XRF) analysis is known for the very short time to result, the high level of accuracy and precision, and the simple sample preparation paired with a high degree of automation, making XRF the best suited analytical method for process and grade control in mining operations. Simultaneous wavelength-dispersive XRF (WDXRF) instruments are delivering accuracy paired with precision in the shortest possible measurement time. A new instrument design combines the analytical performance of the conventional configuration with fixed wavelength-dispersive element channels and a modern simultaneous energy-dispersive detector in order to achieve high analytical precision and accuracy. At the same time, whereas the elements of interest are counted with fixed channels the energy-dispersive detector records the complete spectrum of the sample. This snap-shot of the elemental composition enables all elements present in the sample to be monitored without adding additional measurement time.

Published
2013

59. FeMo cofactor biosynthesis in a nifE(-) mutant of Rhodobacter capsulatus

Author

Siemann, S, Schneider, Klaus, Behrens, K, Knochel, A, Klipp, W, and Müller, Achim

Subjects
Molybdoferredoxin, Hydrogenase, Acetylene, nitrogen fixation, MoFe protein, Electron Spin Resonance Spectroscopy, acetylene reduction, nitrogenase, Rhodobacter capsulatus, EPR spectroscopy
Abstract

In all diazotrophic micro-organisms investigated so far, mutations in nifE, one of the genes involved in the biosynthesis of the FeMo cofactor (FeMoco), resulted in the accumulation of cofactorless inactive dinitrogenase. In this study, we have found that strains of the phototrophic non-sulfur purple bacterium Rhodobacter capsulatus with mutations in nifE, as well as in the operon harbouring the nifE gene, were capable of reducing acetylene and growing diazotrophically, although at distinctly lower rates than the wild-type strain. The diminished rates of substrate reduction were found to correlate with the decreased amounts of the dinitrogenase component (MoFe protein) expressed in R. capsulatus. The in vivo activity, as measured by the routine acetylene-reduction assay, was strictly Mo-dependent. Maximal activity was achieved under diazotrophic growth conditions and by supplementing the growth medium with molybdate (final concentration 20-50 microM). Moreover, in these strains a high proportion of ethane was produced from acetylene ( approximately 10% of ethylene) in vivo. However, in in vitro measurements with cell-free extracts as well as purified dinitrogenase, ethane production was always found to be less than 1%. The isolation and partial purification of the MoFe protein from the nifE mutant strain by Q-Sepharose chromatography and subsequent analysis by EPR spectroscopy and inductively coupled plasma MS revealed that FeMoco is actually incorporated into the protein (1.7 molecules of FeMoco per tetramer). On the basis of the results presented here, the role of NifNE in the biosynthetic pathway of the FeMoco demands reconsideration. It is shown for the first time that NifNE is not essential for biosynthesis of the cofactor, although its presence guarantees formation of a higher content of intact FeMoco-containing MoFe protein molecules. The implications of our findings for the biosynthesis of the FeMoco will be discussed.

Published
2001

61. Irradiance Enhancement Analysis of its Effects and of the PV System Response

Author

Zehner, M., Weigl, T., Czakalla, M., Hartmann, M., Thaler, S., Mayer, B., Betts, T., Gottschalg, R., Behrens, K., Giesler, B., König-Langlo, Gert, Becker, G., Mayer, O., Zehner, M., Weigl, T., Czakalla, M., Hartmann, M., Thaler, S., Mayer, B., Betts, T., Gottschalg, R., Behrens, K., Giesler, B., König-Langlo, Gert, Becker, G., and Mayer, O.

Abstract

The analysis of high resolution measurement data, from Munich, showed significant and repeated irradiation peaks. For irradiation enhancements (IE), the observed irradiation is above the theoretically-calculated global irradiation of a clear sky day (i.e. for the given time with a clear sky and atmosphere). The increased irradiation power is mainly caused by reflections of cumulus clouds. Along with the elevated global irradiation, low ambient and module temperatures were observed, due to cloud coverage between irradiance enhancements peaks. This analysis investigates the essential meteorological observation from these data records. It also depicts the technological effects on the PV-system. To illustrate this, the irradiation peaks are classified by their specific characteristics such as magnitude, period, distribution or slope. Therefore data sets from several Baseline Surface Radiation Network (BSRN) sites, representing various climatic zones are examined to evaluate the magnitude of this effect across Europe and its dependence on general meteorological conditions. It is key to understand the PVsystem’s response to the monitored IE-effects. The employment of the simulation environment INSEL (for various PV-cell types and panels) enables simulations of incorporate high resolution measurement data and (commercially available) PV-module simulation data. The output power of the modules investigated could be up to 30 % higher than under STC conditions. The system response was also explored by using a solar generator simulator and by evaluating operating data sets of MW PV-plants.

Published
2011

62. Cultural aspects of depression

Author

Kastrup, Marianne Carisius, Machleidt, W, Behrens, K, Calliess, I, Kastrup, Marianne Carisius, Machleidt, W, Behrens, K, and Calliess, I

Published
2009

65. Prävalenz, zeitliche Trends und regionale Unterschiede ärztlicher Bewegungsberatung in Deutschland.

Author

Gabrys, L., Jordan, S., Behrens, K., and Schlaud, M.

Subjects
PHYSICAL activity, NON-communicable diseases, HEALTH promotion, PREVENTION, PHYSIOLOGY
Abstract

Copyright of German Journal of Sports Medicine / Deutsche Zeitschrift fur Sportmedizin is the property of Verein zur Forderung der Sportmedizin Hannover e.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Published
2016
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94. Towards an indigenous African bioethics.

Author

Behrens, K. G.

Subjects
BIOETHICS, DIGNITY, VALUES (Ethics), SCIENCE & ethics
Abstract

In response to a perceived moral crisis in South Africa and Africa, I argue that there is a need to seek ways to restore the dignity of the people of Africa, whose values, beliefs and cultures were denigrated in the past. One way is for African bioethicists to begin to apply indigenous African philosophy, thought and values to ethical issues. This project is important (i) to restore dignity; (ii) because a bioethics grounded in indigenous ideas is more likely to be accepted by Africans; and (iii) because such ideas can enrich bioethical discourse. Highlighting the central importance of relationality, community and harmonious relationships in African thought, I conclude that we should adopt a revised version of principlism that incorporates these salient African moral conceptions. [ABSTRACT FROM AUTHOR]

Published
2013
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