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Rumänien vor den Toren der Europäischen Union : Migration, Landwirtschaft und ländlicher Raum
(2001)
In order to broaden our understanding of the eukaryotic CO2- concentrating mechanism the occurrence and localization of a thylakoid-asssocaate carbonic anhydrase (EC 4.2.1.1) were studied in the green algae Tetraedron on minimum and Chlamydomonas noctigama. Both algae induce a CO2-concentrating mechanism when grown under limiting CO2 conditions. Using mass- spectrometric measurements of O-18 exchange from doubly labelled CO2, the presence of a thylakoid-associated carbonic anhydrase was confirmed for both species. From purified thylakoid membranes, photosystem I (PSI), photosystem II (PSII) and the light-harvesting complex of the photosynthetic apparatus were isolated by mild detergent gel. The protein fractions were identified by 77 K fluorescence spectroscopy and immunological studies. A polypeptide was found to immunoreact with an antibody raised against thylakoid carbonic anhydrase (CAH3) from Chlamydomonas reinhardtii. It was found that this polypeptide was mainly associated with PSII, although a certain proportion was also connected to light harvesting complex II. This was confirmed by activity measurements of carbonic anhydrase in isolated bands extracted from the mild detergent gel. The thylakoid carbonic anhydrase isolated from T. minimum had an isoelectric point between 5.4 and 4.8. Together the results are consistent with the hypothesis that thylakoid carbonic anhydrase resides within the lumen where it is associated with the PSII complex.
Thematic cartography
(2001)
Im Handbuchartikel wird eine kurze Übersicht über das Schicksal der Juden seit der Ersten Tschechoslowakischen Republik (1918-1938) bis in die heutige Zeit gegeben. Behandelt werden folgende Fragestellungen: Der rechtliche Status der Juden nach der Verfassung und dem Sprachengesetz von 1920. Die soziale, berufliche und nationale Gliederung des tschechoslowakischen Judentums. Die Lage der Juden im Protektorat Böhmen und Mähren. Das Ghetto Theresienstadt. Nach 1945.
Im vorliegenden Beitrag untersucht Verfasser die Position des niedersorbischen und obersorbischen finiten Verbs im einfachen und komplexen Satz. Entgegen der bisher vertretenen Auffassung, dass das Sorbische eine SOV Sprache sei, wird gezeigt, dass im einfachen Satz mit einem finiten Verb das Os. und Ns. die Verbletzt-Stellung aufweisen, während das Deutsche die obligatorische V2-Position zeigt. Im einfachen Satz mit zusammengesetztem Prädikat (z.B. in temporalen und modalen periphrastischen/analytischen Konstruktionen) muss im Ns. das verbale Auxiliar als Klitik an V2-Position (Wackernagel-Position, möglicherweise Comp) rücken und das Vollverb verbleibt in der VP in situ , während im Os. die Befundlage nicht so eindeutig ist. Die Analyse erfolgt mit Beispielen aus den gesprochenen Dialekten der os. und ns. Sprachen. Der bisher rigoros behauptete und durch Sprachkontakt ausgelöste Einfluss des Deutschen wird zumindest in Bezug auf das Ns. einer Überprüfung unterzogen und relativiert.
Energie
(2001)
Microlensing of Quasars
(2001)
Microlens-induced variability in multiple quasars can be used to study two cosmological issues of great interest, the size and brightness profile of quasars on one hand, and the distribution of compact (dark) matter along the line of sight on the other. Here a summary is given of recent theoretical progress as well as observational evidence for quasar microlensing, plus a discussion of desired observations and required theoretical studies.
The declining light curve of the optical afterglow of gamma-ray burst (GRB) GRB000301C showed rapid variability with one particularly bright feature at about t-t0=3.8d. This event was interpreted as gravitational microlensing by Garnavich, Loeb & Stanek and subsequently used to derive constraints on the structure of the GRB optical afterglow. In this paper, we use these structural parameters to calculate the probability of such a microlensing event in a realistic scenario, where all compact objects in the universe are associated with observable galaxies. For GRB000301C at a redshift of z=2.04, the a posteriori probability for a microlensing event with an amplitude of m>=0.95mag (as observed) is 0.7 per cent (2.7 per cent) for the most plausible scenario of a flat -dominated Friedmann- Robertson-Walker (FRW) universe with m=0.3 and a fraction f*=0.2 (1.0) of dark matter in the form of compact objects. If we lower the magnification threshold to m>=0.10mag, the probabilities for microlensing events of GRB afterglows increase to 17 per cent (57 per cent). We emphasize that this low probability for a microlensing signature of almost 1mag does not exclude that the observed event in the afterglow light curve of GRB000301C was caused by microlensing, especially in light of the fact that a galaxy was found within 2arcsec from the GRB. In that case, however, a more robust upper limit on the a posteriori probability of ~5 per cent is found. It does show, however, that it will not be easy to create a large sample of strong GRB afterglow microlensing events for statistical studies of their physical conditions on microarcsec scales.
Selbstverteidigung
(2001)
Can satiety be measured?
(2001)
An energy-controlled study on a Western diet composed of 45% fat, 40% carbohydrate and 15% protein by energy was carried out. The study consisted of four test phases having a length of 9 days in each case, where 8 healthy free- living subjects were adjusted to individual energy requirements at maintenance level. Between the tests, wash-out phases of 4-5 months were inserted to avoid adaptation effects. By using a standard breakfast of constant composition, satiety was evaluated by applying the concept of categorical comparison, which was based on the common fact, that the perception between two meals is changed and usually a set of sensations can be discriminated. These were termed very full and full (just after finishing a meal), appetite and hungry (just before the next meal). These sensations were used as categories on a categorical scale. The evaluation of satiety was performed such that on each day of the four test phases the subjects had to select over a period of 4 h every 30 min one category out of the four, what corresponded to the individual sensation at that time. This procedure was followed by a mathematical treatment of data such that the individual judgements were transformed into a numerical system. As a result, the time course of satiety was available characterizing the time-dependent change of the interoception after consuming the test meal. Using this concept highly reliable results were obtained as demonstrated by the comparison of the four test series.
The Problem of front propagation in flowing media is addressed for laminar velocity fields in two dimensions. Three representative cases are discussed: stationary cellular flow, stationary shear flow, and percolating flow. Production terms of Fisher-Kolmogorov-Petrovskii-Piskunov type and of Arrhenius type are considered under the assumption of no feedback of the concentration on the velocity. Numerical simulations of advection-reaction-diffusion equations have been performed by an algorithm based on discrete-time maps. The results show a generic enhancement of the speed of front propagation by the underlying flow. For small molecular diffusivity, the front speed <i>V<sub><i>f</sub> depends on the typical flow velocity <i>U as<sup> </sup>a power law with an exponent depending on the topological properties of the flow, and on the ratio of reactive and advective time scales. For open-streamline flows we find always<sup> </sup><i>V<sub><i>f</sub>~<i>U, whereas for cellular flows we observe <i>V<sub><i>f</ sub>~<i>U<sup>1/4</sup> for fast advection and <i>V<sub><i>f</sub>~<i>U<sup>3/4</sup> for slow advection.
Motivationstraining
(2001)