Structural Basis for the Aminoacid Composition of Proteins from Halophilic Archea

In order to survive in highly saline environments, proteins from halophilic archea have evolved with biased amino acid compositions that have the capacity to reduce contacts with the solvent

Analysis of the impact of length of stay on the quality of service experience, satisfaction and loyalty

Although length of stay is a relevant variable in destination management, little research has been produced connecting it with tourists' post-consumption behaviour. This research compares the post-consumption behaviour of same-day visitors with overnight tourists in a sample of 398 domestic vacationers at two Mediterranean heritage-and-beach destinations. Although economic research on length of stay posits that there are destination benefits in longer stays, same-day visitors score higher in most of the post-consumption variables under study. Significant differences arise in hedonic aspects of the tourist experience and destination loyalty. Thus, we propose that length of stay can be used as a segmentation variable. Furthermore, destination management organisations need to consider length of stay when designing tourism policies. The tourist product and communication strategies might be adapted to different vacation durations

Similarities and differences in the autonomic control of airway and urinary bladder smooth muscle

The airways and the urinary bladder are both hollow organs serving very different functions, i.e. air flow and urine storage, respectively. While the autonomic nervous system seems to play only a minor if any role in the physiological regulation of airway tone during normal breathing, it is important in the physiological regulation of bladder smooth muscle contraction and relaxation. While both tissues share a greater expression of M2 than of M3 muscarinic receptors, smooth muscle contraction in both is largely mediated by the smaller M3 population apparently involving phospholipase C activation to only a minor if any extent. While smooth muscle in both tissues can be relaxed by β-adrenoceptor stimulation, this primarily involves β2-adrenoceptors in human airways and β3-adrenoceptors in human bladder. Despite activation of adenylyl cyclase by either subtype, cyclic adenosine monophosphate plays only a minor role in bladder relaxation by β-agonists; an important but not exclusive function is known in airway relaxation. While airway β2-adrenoceptors are sensitive to agonist-induced desensitization, β3-adrenoceptors are generally considered to exhibit much less if any sensitivity to desensitization. Gene polymorphisms exist in the genes of both β2- and β3-adrenoceptors. Despite being not fully conclusive, the available data suggest some role of β2-adrenoceptor polymorphisms in airway function and its treatment by receptor agonists, whereas the available data on β3-adrenoceptor polymorphisms and bladder function are too limited to allow robust interpretation. We conclude that the distinct functions of airways and urinary bladder are reflected in a differential regulation by the autonomic nervous system. Studying these differences may be informative for a better understanding of each tissue

Metabolism of halophilic archaea

In spite of their common hypersaline environment, halophilic archaea are surprisingly different in their nutritional demands and metabolic pathways. The metabolic diversity of halophilic archaea was investigated at the genomic level through systematic metabolic reconstruction and comparative analysis of four completely sequenced species: Halobacterium salinarum, Haloarcula marismortui, Haloquadratum walsbyi, and the haloalkaliphile Natronomonas pharaonis. The comparative study reveals different sets of enzyme genes amongst halophilic archaea, e.g. in glycerol degradation, pentose metabolism, and folate synthesis. The carefully assessed metabolic data represent a reliable resource for future system biology approaches as it also links to current experimental data on (halo)archaea from the literature

On the determination of the drift perpendicular to the magnetic field by means of a probe

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On a criterion for a plasma-wall-interaction in a reactor

A criterion is formulated for the permissible degree of plasmawall-interaction of a thermonuclear plasma. Taking the growth of $\alpha$-particle concentration as a measure, the criterion is expressed in form of a simple relation between few characteristics such as "relative toxicity" and "energy related material yield". The criterionis applied to the example of sputtering by fuel particles in the presence of a cool plasma mantle showing that high-Z materials like tungsten might become advantageous if the "temperature" of the bombarding particles is in the range between 10 and 25 eV

On the determination of the ion drift speed perpendicular to the magnetic field by means of a probe

In an attempt to determine the flow speed of ions perpendicular to the magnetic field the effective area of the probe pins has to be known. Its value depend on the value of the electric field in the presheth of the pin and can be significantly larger than the geometrical area. It is demonstrated that without considering the effect of the presheath even the determined direction of the flow can be wrong. Probe signals obtained by means of the Rotating Double Cylinder Probe give an indication of the importance of the presheath effect in a plasma with cross field flow. A new probe head design is presented which might be suited to determine the cross field flow speed. First results are discussed