Raman cooling and heating of two trapped Ba+ ions

We study cooling of the collective vibrational motion of two 138Ba+ ions confined in an electrodynamic trap and irradiated with laser light close to the resonances S_1/2-P_1/2 (493 nm) and P_1/2-D_3/2 (650 nm). The motional state of the ions is monitored by a spatially resolving photo multiplier. Depending on detuning and intensity of the cooling lasers, macroscopically different motional states corresponding to different ion temperatures are observed. We also derive the ions' temperature from detailed analytical calculations of laser cooling taking into account the Zeeman structure of the energy levels involved. The observed motional states perfectly match the calculated temperatures. Significant heating is observed in the vicinity of the dark resonances of the Zeeman-split S_1/2-D_3/2 Raman transitions. Here two-photon processes dominate the interaction between lasers and ions. Parameter regimes of laser light are identified that imply most efficient laser cooling.Comment: 8 pages, 5 figure

Degradation Kinetics of Lignocellulolytic Enzymes in a Biogas Reactor Using Quantitative Mass Spectrometry

The supplementation of lignocellulose-degrading enzymes can be used to enhance the performance of biogas production in industrial biogas plants. Since the structural stability of these enzyme preparations is essential for efficient application, reliable methods for the assessment of enzyme stability are crucial. Here, a mass-spectrometric-based assay was established to monitor the structural stability of enzymes, i.e., the structural integrity of these proteins, in anaerobic digestion (AD). The analysis of extracts of Lentinula edodes revealed the rapid degradation of lignocellulose-degrading enzymes, with an approximate half-life of 1.5 h. The observed low structural stability of lignocellulose-degrading enzymes in AD corresponded with previous results obtained for biogas content. The established workflow can be easily adapted for the monitoring of other enzyme formulations and provides a platform for evaluating the effects of enzyme additions in AD, together with a characterization of the biochemical methane potential used in order to determine the biodegradability of organic substrates

Organisms in experimental research

Rachel A. Ankeny and Sabina Leonell

Vaccines - Patenting Dynamics of a Powerful Healthcare Tool

Vaccines are condidered to be some of the most powerful healthcare tools of this century. From an industrial perspective, in the past they have not provided particulary attractive targets for investment, but this situation changed dramatically in the late eighties and early nineties wieth governmental initiatives aimed at stabilising the vaccine liability situation together with advances in molecular biology and the emergence of biotechnology, opening-up new opportunities for solving the scientific problems associated with vaccine developments. This paper analyses how these developments are reflected in patenting activities wordwide. The comparison of vaccine patent applications with pharmaceutival patents as a whole indicates the vaccine research has been a very dynamic field during the last 15 years, total paten applications increased by a factor of 7,5 between 1980 andn1994. Genetic engineering approaches have established themselves as a key tools for vaccine R&D, such techniques be ing applied in more than 50 % of all vaccine patent applications are mainly driven by the US and Europe, which together contributed 91% of all patents in 1994. Within Europe, France, Germany, Great Britain and Italy are the most active countries. Key players in vaccine patenting are American governmental agencies, international pharmaceutical corparoations, biotech-firms, universities and non-univierity public research organisations. All-in-all, public research activities seem to play a crcial role in the creation of scientific and technological knowledge for the devolopment of new vaccines