A phenomenological interpretation of open charm production at HERA in terms of the semi-hard approach

In the framework of the semi-hard (k_t-factorization) approach, we analyze the various charm production processes in the kinematic region covered by the HERA experiments.Comment: DESY 02-017, LUNFD6/(NFFL--7209) 200

Payload operations management of a planned European SL-Mission employing establishments of ESA and national agencies

Spacelab (SL)-missions with Payload Operations (P/L OPS) from Europe involve numerous space agencies, various ground infrastructure systems and national user organizations. An effective management structure must bring together different entities, facilities and people, but at the same time keep interfaces, costs and schedule under strict control. This paper outlines the management concept for P/L OPS of a planned European SL-mission. The proposal draws on the relevant experience in Europe, which was acquired via the ESA/NASA mission SL-1, by the execution of two German SL-missions and by the involvement in, or the support of, several NASA-missions

Molekulardynamische Simulation idealer Gase mit Delphi

Vorgestellt wird ein Windows-Programm zur Simulation einatomiger idealer Gase, deren Molek¨ule als elastische harte Kugeln mit glatter Oberfl¨ache modelliert sind. Mit der Beschr¨ankung auf ideale Gase lassen sich die Bewegungsvorg¨ange in gr¨oßeren Schrittweiten berechnen als mit heute ¨ublichen Molekulardynamikprogrammen. Allerdings k¨onnen damit weder Phasen¨uberg¨ange zufl¨ussigen und festen Zust¨anden oder sonstige Eigenschaften realer Gase modelliert werden. Das Programm ist jedoch gut geeignet, bestimmte Aussagen der urspr¨unglichen kinetischen Gastheorie von Clausius, Maxwell und Boltzmann anschaulich zu demonstrieren

Making sense: dopamine activates conscious self-monitoring through medial prefrontal cortex

When experiences become meaningful to the self, they are linked to synchronous activity in a paralimbic network of self-awareness and dopaminergic activity. This network includes medial prefrontal and medial parietal/posterior cingulate cortices, where transcranial magnetic stimulation may transiently impair self-awareness. Conversely, we hypothesize that dopaminergic stimulation may improve self-awareness and metacognition (i.e., the ability of the brain to consciously monitor its own cognitive processes). Here, we demonstrate improved noetic (conscious) metacognition by oral administration of 100 mg dopamine in minimal self-awareness. In a separate experiment with extended self-awareness dopamine improved the retrieval accuracy of memories of self-judgment (autonoetic, i.e., explicitly self-conscious) metacognition. Concomitantly, magnetoencephalography (MEG) showed increased amplitudes of oscillations (power) preferentially in the medial prefrontal cortex. Given that electromagnetic activity in this region is instrumental in self-awareness, this explains the specific effect of dopamine on explicit self-awareness and autonoetic metacognition

Caring for Blue-Green Solutions (BGS) in Everyday Life: An Investigation of Recreational Use, Neighborhood Preferences and Willingness to Pay in Augustenborg, Malmo

In this article, we explore the production of socio-cultural values around blue-green solutions (BGS) through the perspective of care. We explore how values and preferences are formed through the complexity of everyday life engagements in a BGS environment. The data come from a questionnaire answered by 328 households in the neighborhood of Augustenborg in Malmo, Sweden. The questionnaire collects detailed information about inhabitants' possible recreational use (through Likert scale questions) and willingness to pay (WTP) (estimated through contingent valuation). The study evaluates if and how people care to use, care to live with, and care to pay for BGS. The result shows that people in Augustenborg relate in different and sometimes contradictory ways to BGS. A well-used BGS environment does not per se make the environment successful or result in people preferring a BGS environment in the future. Building awareness about BGS seems to increase the willingness to pay, whereas recreational use seems to decrease it. The study reveals a landscape of care that is constantly being formed and transformed. This suggests that both planning and research needs to focus more on the relation between BGS and social use over time

Experiences with dormancy in tardigrades.

Tardigrades often colonise extreme habitats, in which they survive using both types of dormancy: quiescence and diapause. Together with nematodes and bdelloid rotifers, tardigrades are known to enter quiescence (with several forms of cryptobiosis: anhydrobiosis, cryobiosis, anoxybiosis, osmobiosis) at any stage of their life cycle, from egg to adult. Entering anhydrobiosis, tardigrades contract their body into a so-called tun, loosing most of their free and bound water (> 95%), synthesizing cell protectants (e.g., trehalose, glycerol, heat shock proteins) and strongly reducing or suspending their metabolism. Our research on cryptobiosis focused on some ecological and evolutionary aspects. We evaluated: i) the long-term anhydrobiotic survival by comparing quantitative data on recovery from naturally induced desiccation in several species of tardigrades; ii) differences in survival patterns between species and populations by experimentally inducing anhydrobiosis and cryobiosis; iii) phenotypic factors affecting anhydrobiotic survival. As regards diapause, we considered encystment and eggs. Encystment involves at least the synthesis of new cuticular structures. Morphological changes during cyst formation are more complex than those involved in tun formation. We analyzed more in detail encystment processes, comparing a semiterrestrial with a limnic species. Several inter-specific differences have been identified, other than the production of two types of cysts in the semiterrestrial species. Our analysis of life history traits of a laboratory reared strain of a soil tardigrade revealed a particular hatching phenology that involved the production of both subitaneous and resting eggs. The latter need a cue to hatch (dehydration followed by re-hydration). In addition, the evolutionary meaning of dormancy in tardigrades is discussed

High-throughput screening for industrial enzyme production hosts by droplet microfluidics

A high-throughput method for single cell screening by microfluidic droplet sorting is applied to a whole-genome mutated yeast cell library yielding improved production hosts of secreted industrial enzymes. The sorting method is validated by enriching a yeast strain 14 times based on its a-amylase production, close to the theoretical maximum enrichment. Furthermore, a 105 member yeast cell library is screened yielding a clone with a more than 2-fold increase in a-amylase production. The increase in enzyme production results from an improvement of the cellular functions of the production host in contrast to previous droplet-based directed evolution that has focused on improving enzyme protein structure. In the workflow presented, enzyme producing single cells are encapsulated in 20 pL droplets with a fluorogenic reporter substrate. The coupling of a desired phenotype (secreted enzyme concentration) with the genotype (contained in the cell) inside a droplet enables selection of single cells with improved enzyme production capacity by droplet sorting. The platform has a throughput over 300 times higher than that of the current industry standard, an automated microtiter plate screening system. At the same time, reagent consumption for a screening experiment is decreased a million fold, greatly reducing the costs of evolutionary engineering of production strains

Single-cell screening of photosynthetic growth and lactate production by cyanobacteria

Background Photosynthetic cyanobacteria are attractive for a range of biotechnological applications including biofuel production. However, due to slow growth, screening of mutant libraries using microtiter plates is not feasible. Results We present a method for high-throughput, single-cell analysis and sorting of genetically engineered l-lactate-producing strains of Synechocystis sp. PCC6803. A microfluidic device is used to encapsulate single cells in picoliter droplets, assay the droplets for l-lactate production, and sort strains with high productivity. We demonstrate the separation of low- and high-producing reference strains, as well as enrichment of a more productive l-lactate-synthesizing population after UV-induced mutagenesis. The droplet platform also revealed population heterogeneity in photosynthetic growth and lactate production, as well as the presence of metabolically stalled cells. Conclusions The workflow will facilitate metabolic engineering and directed evolution studies and will be useful in studies of cyanobacteria biochemistry and physiology