Altern und Sexualität

Dieser Beitrag gibt einen einführenden Überblick zum sexuellen Verhalten und Erleben von Menschen im mittleren und höheren Erwachsenenalter. Grundlage dafür ist eine Studie aus der deutschsprachigen Schweiz mit 641Männern (45-91Jahre) und 857Frauen (45-86Jahre). Altersbedingte hormonale und anatomische Veränderungen und deren Auswirkungen auf die sexuellen Reaktionen werden kurz beschrieben. Sexuelles Interesse, sexuelle Aktivität und Zufriedenheit, gesundheitliche Einflüsse darauf sowie Gründe sexueller Inaktivität werden dargestellt. Die Medikalisierung der Sexualität alternder Menschen wird kritisch beleuchtet. Zusammenfassende Empfehlungen für die Praxis werden gegebe

Thermal phase transitions for Dicke-type models in the ultra-strong coupling limit

We consider the Dicke model in the ultra-strong coupling limit to investigate thermal phase transitions and their precursors at finite particle numbers $N$ for bosonic and fermionic systems. We derive partition functions with degeneracy factors that account for the number of configurations and derive explicit expressions for the Landau free energy. This allows us to discuss the difference between the original Dicke (fermionic) and the bosonic case. We find a crossover between these two cases that shows up, e.g., in the specific heat.Comment: 4 pages Brief Report styl

Observation of Modulated Quadrupolar Structures in PrPb3

Neutron diffraction measurements have been performed on the cubic compound PrPb3 in a [001] magnetic field to examine the quadrupolar ordering. Antiferromagnetic components with q=(1/2+-d 1/2 0), (1/2 1/2+-d 0) (d~1/8) are observed below the transition temperature TQ (0.4 K at H=0) whose amplitudes vary linear with H and vanish at zero field, providing the first evidence for a modulated quadrupolar phase. For H<1 T, a non-square modulated state persists even below 100 mK suggesting quadrupole moments associated with a Gamma3 doublet ground state to be partially quenched by hybridization with conduction electrons.Comment: Physical Review Letters, in press. 4 pages, 4 figure

Antiferro-quadrupole state of orbital-degenerate Kondo lattice model with f^2 configuration

To clarify a key role of $f$ orbitals in the emergence of antiferro-quadrupole structure in PrPb$_{3}$, we investigate the ground-state property of an orbital-degenerate Kondo lattice model by numerical diagonalization techniques. In PrPb$_{3}$, Pr$^{3+}$ has a $4f^{2}$ configuration and the crystalline-electric-field ground state is a non-Kramers doublet $\Gamma_{3}$. In a $j$-$j$ coupling scheme, the $\Gamma_{3}$ state is described by two local singlets, each of which consists of two $f$ electrons with one in $\Gamma_{7}$ and another in $\Gamma_{8}$ orbitals. Since in a cubic structure, $\Gamma_{7}$ has localized nature, while $\Gamma_{8}$ orbitals are rather itinerant, we propose the orbital-degenerate Kondo lattice model for an effective Hamiltonian of PrPb$_{3}$. We show that an antiferro-orbital state is favored by the so-called double-exchange mechanism which is characteristic of multi-orbital systems.Comment: 3 pages, 3 figures, Proceedings of Skutterudite2007 (September 26-30, 2007, Kobe

Erektile Dysfunktion bei Männern in der zweiten Lebenshälfte

Zusammenfassung: Hintergrund: Bisherige Studien zur Prävalenz der erektilen Dysfunktion (ED) zeigen unterschiedliche Ergebnisse. Mit der vorliegenden Studie werden die Häufigkeit und graduelle Ausprägung der ED, deren begünstigende Faktoren sowie das Hilfesuchverhalten der Betroffenen untersucht. Stichprobe und Methodik: Eine Zufallsstichprobe von 628 Deutschschweizer Männern (Durchschnittsalter 61,5Jahre) wurde mittels Fragebogen zur sexuellen Funktionsfähigkeit, Komorbidität und zu ihrem Hilfesuchverhalten befragt. Ergebnisse: 9,6% der Befragten berichten über eine vollständige, 18,0% über eine moderate und 41,4% über eine minimale ED. Alle Grade der Störung nehmen mit dem Alter zu und korrelieren mit somatischer bzw. psychischer Komorbidität sowie Medikamenteneinnahme. Nur 3,2% geben an, schon Mittel zur Verbesserung der Erektionsfähigkeit eingenommen bzw. verwendet zu haben. Schlussfolgerungen: Nur ein kleiner Teil von Männern mit ED sucht ärztliche Hilfe. Sachliche Aufklärung und kompetente ärztliche Beratung von Betroffenen erscheinen angesichts der guten Wirksamkeit von PDE-5-Hemmern angebrach

On applications and limitations of one-dimensional capillarity formulations for media with heterogeneous wettability

Force-balance-based one-dimensional algebraic formulations that are often used in characterizing the capillarity of a multi-component system (e.g., predicting capillary height rise inporous media) are discussed. It is shown that such formulations fail to provide accurate predictions when the distribution of wetting (or non-wetting) surfaces is not homogeneous. A more general mathematical formulation is suggested and used to demonstrate that for media with heterogeneous wettability, hydrophilic (or hydrophobic) surfaces clustered in groups will have less contribution to the overall capillarity of the system

A note on semi-conjugacy for circle actions

We define a notion of semi-conjugacy between orientation-preserving actions of a group on the circle, which for fixed point free actions coincides with a classical definition of Ghys. We then show that two circle actions are semi-conjugate if and only if they have the same bounded Euler class. This settles some existing confusion present in the literature

Reaction Textures and Metamorphic Evolution of Sapphirine-bearing Granulites from the Gruf Complex, Italian Central Alps

Mineral chemistries and textures are described from a suite of sapphirine-bearing granulites from the Gruf Complex of the Italian Central Alps. The granulites contain combinations of garnet, orthopyroxene, sapphirine, sillimanite, cordierite, biotite, quartz, spinel, corundum, staurolite, plagioclase, K-feldspar, ilmenite and rutile, in assemblages with low (usually negative) variance. They are outstanding in that they preserve a textural and chemical record of a protracted metamorphic evolution. Reaction textures are common and include: (i) pseudomorphs (e.g. of sillimanite after kyanite); (ii) relatively coarse-grained monomineralic reaction rims (e.g. of cordierite between sapphirine and quartz); (iii) fine-grained symplectitic coronas (e.g. of orthopyroxene + sapphirine round garnet); (iv) inclusions, in garnet cores, of minerals (e.g. staurolite) not found elsewhere in the rocks. Detailed microprobe study has revealed large chemical variations within each phase. Different textural types of each phase have different compositions, and strong zoning is preserved in garnet (Mg/(Mg + Fe) from 0.30 to 0.61) and coarse sapphirine. Inclusion populations in garnet correlate with host composition. The textural and chemical features are interpreted in terms of successive equilibrium assemblages and reactions. Metamorphic conditions operative at each stage in the evolution are calculated using published geothermometers and geobarometers as well as thermodynamically calibrated MAS and FASH equilibria. The results are used to construct a P—T-time path for the sapphirine-granulites, which can be summarized as follows: (i) Increasing T at high P (>7 kb). Partial melting. (ii) A maximum T of ∼830 °C attained at ∼10 kb. (iii) Almost isothermal decompression, reaching 750 °C at ∼5 kb, under conditions of low μH2O. (iv) Further cooling, and decompression. Localized hydration. Rocks exposed. The P—T-time path is interpreted as the product of a single metamorphic cycle (the tertiary ‘Lepontine' event) and is extrapolated to the Gruf Complex as a whole. When combined with published geochronological data, the results indicate an average uplift rate in excess of 2 mm/yr for the Gruf Complex between 38 and 30 Ma ago. An in situ partial melting origin for the sapphirine-granulites is favoured. Extraction of an iron-rich granitic liquid from a normal pelitic palaeosome could generate a refractory residue with the required Mg, Al-rich composition. The change in bulk solid composition during partial melting is thought to account for the extraordinarity strong zoning in the garnet