Refined carotenoid analysis of the major light-harvesting complex of Mantoniella squamata

The major light-harvesting complex (LHC) of the prasinophycean alga Mantoniella squamata is unique compared to other chlorophyll (Chl) a/b-binding LHC with respect to the primary protein structure and the pigmentation. Although the presence of Chl a, Chl b, a Chl c-type pigment and the xanthophylls neoxanthin, violaxanthin and prasinoxanthin was clearly determined, several carotenoids remained unidentified or were described controversially. We re-analysed the carotenoid composition and identified a new set of xanthophylls present in the LHC: uriolide, micromonol, micromonal and dihydrolutein. Additionally, one hydrophobic component was detected, presumably a xanthophyll. The pigment analysi…

Der ökonomische Ansatz

Der Beitrag stellt, ganz wesentlich orientiert an Downs‘ Modell, den okonomischen Ansatz und das damit verbundene Forschungsprogramm in der Wahlforschung vor. Es werden die zentralen Modellannahmen dargestellt und daraus wichtige Schlusfolgerungen, etwa die rationale Ignoranz und das Wahlparadoxon, abgeleitet. Anschliesend werden Anwendungen und Erweiterungen, u.a. Informationskosten, Ideologien, mehrere Politikdimensionen, Naherungs- und Richtungsmodelle, die Salienztheorie und Economic Voting, diskutiert. Zudem werden verschiedene Losungsansatze fur das Wahlparadoxon vorgestellt. Abschliesend wird der Wert des Rational-Choice-Ansatzes fur die Wahlforschung diskutiert.

Determination of the154Sm ionization energy by high-precision laser spectroscopy

High-resolution resonance ionization mass spectrometry has been used to determine the ionization energy of 154Sm. Three-step resonant excitation with single-frequency lasers populates a series of ? = 3, J = 4 Rydberg levels in the range of n = 60?160, covering the range of 30 cm?1 to 4 cm?1 below the first ionization limit. Although samarium has a complex electronic structure with eight valence electrons, series of nearly unperturbed levels could be observed. Analysis includes shifts caused by a single perturbing state, an extended Ritz term for quantum defect variation at lower n, and corrections for residual electric fields. The resulting series convergence limit has an uncertainty of 4 ?…

Dirty Hands? No (Moral) Problem!

In his famous 1973 paper, Michael Walzer introduced “The Problem of Dirty Hands” to political philosophy. A decision-maker, according to Walzer, is “trapped” in a dirty hands-situation if his decision and ensuing actions “may be exactly the right thing to do […] and yet leave the man guilty of a moral wrong. The innocent man, afterwards, is no longer innocent” (Walzer 1973: 160).

Die Rolle von Wahlen in der Demokratie

Der Beitrag diskutiert Wahlen im Lichte ausgewahlter Demokratietheorien. Fur diese Theorien zeichnen sich demokratische Wahlen dadurch aus, das alle Burger in regelmasigen Abstanden eine freie Wahl zwischen mindestens zwei Kandidaten oder Parteien treffen konnen und das Wahlergebnis verbindliche Wirkung hat. Die Theorien unterscheiden sich jedoch darin, welchen Wert sie Wahlen fur die Verwirklichung demokratischer Werte zuschreiben. Elitistische oder okonomische Theorien (Weber, Schumpeter, Downs) sehen Wahlen als notwendige und hinreichende Bedingung fur die Verwirklichung demokratischer Werte. Fur sozialliberale und republikanische Theoretiker (Rawls, Pettit) sind Wahlen nur eine notwendi…

Isotope shifts and hyperfine structure in the $\mathsf{ 3d ^2D_J \rightarrow 4p ^2P_J}$ transitions in calcium II

The isotope shift and hyperfine structure in the three \(\) - transitions in Ca II have been studied by fast ion beam collinear laser spectroscopy for all stable Ca isotopes. The metastable 3d states were populated within the surface ionization source of a mass separator with a probability of about 0.1%. After resonant excitation to the 4p levels with diode laser light around 850 nm the uv photons from the \(\) transitions to the ground state were used for detection. Hyperfine structure parameters A and B for the odd isotope 43Ca, as evaluated from the splittings observed, agree well with theoretical predictions from relativistic many-body perturbation theory. Field shift constants \(\) and…

Determination of the helium-4 mass in a Penning trap

We have measured the cyclotron frequencies of He+, H+ 2 and D+ 2 ions in a room temperature Penning trap. The resonances were detected destructively by a time-of-flight technique. The statistical uncertainty of the resonance frequencies was generally below 1 ppb. A detailed account of measures to minimize systematic frequency shift is presented. Using the accepted values for the proton and deuteron mass we obtain a value for the 4He mass: M(4 He) = 4.0026032489(22) (0.5 ppb). It is in agreement with the accepted value.

Isotope shifts and hyperfine structure in the transitions of gadolinium

High-resolution resonance ionization mass spectrometry has been used to measure isotope shifts and hyperfine structure in all (J = 2-6) and the transitions of gadolinium (Gd I). Gadolinium atoms in an atomic beam were excited with a tunable single-frequency laser in the wavelength range of 422-429 nm. Resonant excitation was followed by photoionization with the 363.8 nm line of an argon ion laser and resulting ions were mass separated and detected with a quadrupole mass spectrometer. Isotope shifts for all stable gadolinium isotopes in these transitions have been measured for the first time. Additionally, the hyperfine structure constants of the upper states have been derived for the isotop…

Thermische Denaturierung von Kaltblüter-Enzymproteinen

The temperature, which leads to 50% reduction of catalytic activity by heat denaturation, has been determined for 8 different enzymes from cod muscle, as being in the range between 30 and 52°C. Therefore, there are no indications of a generally different heat resistance of enzymes from cold-blooded animals as compared with those from warm-blooded animals. The same conclusion is derived from calculations ofQ10-values, measured between +37 and − 37°C for cathepsin and glycylglycine dipeptidase.

Properties and performance of a quadrupole mass filter used for resonance ionization mass spectrometry

Abstract The performance of commercial quadrupole mass spectrometers (QMS) with a number of imperfections, as compared to the ideal hyperbolic geometry, has been characterized using the computer simulation program simion 3d version 6.0. The analysis of simulated QMS geometries focuses primarily on modeling of the internal potential, the study of field deviations, and the influence of finite length on performance of the QMS. The computer simulation of ion trajectories in the QMS field yields predictions for optimum working conditions and provides estimates for the resolving power and the maximum isotopic abundance sensitivity. Experimental measurements that confirm these expectations are pre…

Isolierung und Eigenschaften von Lipofuscin aus Herzgewebe des Menschen

A histological study of a femur of Plagiosuchus, a Middle Triassic temnospondyl amphibian from southern GEmany, using thin sections and micro-CT scanning

AbstractThe histology of a femur of Plagiosuchus, a Middle Triassic temnospondyl amphibian, is described on the basis of two supplementary methods: classic thin sectioning and micro-CT scanning. In addition, the effectiveness of high-resolution micro-CT scanning for histological analysis is assessed. A classic, mid-shaft thin section of the femur was prepared, but prior to slicing two micro-CT scans were made. One of these has an image stack of a total of 1,024 images in the horizontal plane and a slice thickness of 87.8 μm, so that the entire bone could be captured, while the second was at mid-shaft region only, yet with a higher resolution of 28.3 μm and an image stack of 787 images in th…

Recent developments in and applications of resonance ionization mass spectrometry

Resonance Ionization Mass Spectrometry (RIMS) has nowadays reached the status of a routine method for sensitive and selective ultratrace determination of long-lived radioactive isotopes in environmental, biomedical and technical samples. It provides high isobaric suppression, high to ultra-high isotopic selectivity and good overall efficiency. Experimental detection limits are as low as 106 atoms per sample and permit the fast and sensitive determination of ultratrace amounts of radiotoxic contaminations. Experimental arrangements for the detection of different radiotoxic isotopes, e.g. 236–244Pu, 89,90Sr and 99Tc in environmental samples are described, and the application of RIMS to the ul…

THE LIGHT-HARVESTING SYSTEM OF THE UNICELLULAR ALGA Mantoniella squamata (PRASINOPHYCEAE): EVIDENCE FOR THE LACK OF A PHOTOSYSTEM I-SPECIFIC ANTENNA COMPLEX

The light-harvesting complexes (LHC) were isolated from the unicellular alga Mantoniella squamata (Prasinophyceae) by sucrose-density centrifugation. Beside the major LHC (II), a photosystem I complex was obtained that could be dissociated into a photosystem I core complex and an associated LHC I. In contrast to other chlorophyll b-containing antennae, both LHC II as well as LHC I were observed to be identical with respect to the following features: the molecular weights, the isoelectric points and the retention behavior on anion-exchange chromatography of the apoproteins, the pigment content and the absorption and fluorescence spectra

QCD and Strongly Coupled Gauge Theories: Challenges and Perspectives

We dedicate this document to the memory of Mikhail Polikarpov, who passed away in July 2013. Misha worked with us for decades as a convener of the “Confinement” section of the Quark Confinement and Hadron Spectrum Series. He guided and expanded the scientific discussion of that topic, inspiring and under taking new research avenues. From its initial conception, he supported the enterprise of this document and organized Sect. 8, writing the part on confinement himself. He attracted the XIth Conference on Quark Confinement and the Hadron Spectrum to St. Petersburg (September 8-12, 2014; see http://phys.spbu.ru/confxi.html). His warm and kind personality, his high sense of humor, his ideas in …