Seelische Belastung bei Menschen mit umweltbezogenen Störungen: Ein Vergleich zwischen Selbstbild und Fremdeinschätzung

Zusammenfassung: Umweltbezogene Gesundheitsstörungen stellen wissenschaftlich und klinisch ein diagnostisches und therapeutisches Konfliktfeld dar. Ein hoher subjektiver Leidensdruck, ein somatisches Krankheitsmodell sowie das Festhalten an einer Umweltursache gefährden die therapeutische Beziehung, wenn die Krankheitsmodelle von Arzt und Patient nicht übereinstimmen. Unsere Untersuchung greift diese empirisch noch kaum erforschte Diskrepanz auf, indem sie die Selbsteinschätzung von Patienten mit umweltbezogenen Krankheitsstörungen (n=61) systematisch der Fremdeinschätzung durch ein multidisziplinäres Expertenteam gegenüberstellt. Die Resultate weisen darauf hin, dass in Selbst- und Fremdeinschätzung psychisch unauffällige Probanden wenig psychiatrische Störungen zeigen, über stabile psychische Strukturen verfügen und v.a. unter umweltbedingten oder medizinischen Ursachen leiden. Wenn Selbst- und Fremdeinschätzung beide eine psychische Auffälligkeit beschreiben, sind entsprechend psychiatrische Störungen gehäuft, psychische Strukturen labil, und die Beschwerden werden psychiatrisch verursacht. Divergieren Selbst- und Fremdeinschätzung, erlaubt die Fremdeinschätzung akkuratere Aussagen bezüglich der psychiatrischen Diagnosen, der innerpsychischen Struktur und der Ursachenzuschreibun

High-dimensional quantum dynamics of adsorption and desorption of H2_2 at Cu(111)

We performed high-dimensional quantum dynamical calculations of the dissociative adsorption and associative desorption of hydrogen on Cu(111). The potential energy surface (PES) is obtained from density functional theory calculations. Two regimes of dynamics are found, at low energies sticking is determined by the minimum energy barrier, at high energies by the distribution of barrier heights. Experimental results are well-reproduced qualitatively, but some quantitative discrepancies are identified as well.Comment: 4 two column pages, revtex, 4 figures, to appear in Phys. Rev. Let

Electronic Collective Modes and Superconductivity in Layered Conductors

A distinctive feature of layered conductors is the presence of low-energy electronic collective modes of the conduction electrons. This affects the dynamic screening properties of the Coulomb interaction in a layered material. We study the consequences of the existence of these collective modes for superconductivity. General equations for the superconducting order parameter are derived within the strong-coupling phonon-plasmon scheme that account for the screened Coulomb interaction. Specifically, we calculate the superconducting critical temperature Tc taking into account the full temperature, frequency and wave-vector dependence of the dielectric function. We show that low-energy plasmons may contribute constructively to superconductivity. Three classes of layered superconductors are discussed within our model: metal-intercalated halide nitrides, layered organic materials and high-Tc oxides. In particular, we demonstrate that the plasmon contribution (electronic mechanism) is dominant in the first class of layered materials. The theory shows that the description of so-called ``quasi-two-dimensional superconductors'' cannot be reduced to a purely 2D model, as commonly assumed. While the transport properties are strongly anisotropic, it remains essential to take into account the screened interlayer Coulomb interaction to describe the superconducting state of layered materials.Comment: Final version (minor changes) 14 pages, 6 figure

Ab initio Quantum and ab initio Molecular Dynamics of the Dissociative Adsorption of Hydrogen on Pd(100)

The dissociative adsorption of hydrogen on Pd(100) has been studied by ab initio quantum dynamics and ab initio molecular dynamics calculations. Treating all hydrogen degrees of freedom as dynamical coordinates implies a high dimensionality and requires statistical averages over thousands of trajectories. An efficient and accurate treatment of such extensive statistics is achieved in two steps: In a first step we evaluate the ab initio potential energy surface (PES) and determine an analytical representation. Then, in an independent second step dynamical calculations are performed on the analytical representation of the PES. Thus the dissociation dynamics is investigated without any crucial assumption except for the Born-Oppenheimer approximation which is anyhow employed when density-functional theory calculations are performed. The ab initio molecular dynamics is compared to detailed quantum dynamical calculations on exactly the same ab initio PES. The occurence of quantum oscillations in the sticking probability as a function of kinetic energy is addressed. They turn out to be very sensitive to the symmetry of the initial conditions. At low kinetic energies sticking is dominated by the steering effect which is illustrated using classical trajectories. The steering effects depends on the kinetic energy, but not on the mass of the molecules. Zero-point effects lead to strong differences between quantum and classical calculations of the sticking probability. The dependence of the sticking probability on the angle of incidence is analysed; it is found to be in good agreement with experimental data. The results show that the determination of the potential energy surface combined with high-dimensional dynamical calculations, in which all relevant degrees of freedon are taken into account, leads to a detailed understanding of the dissociation dynamics of hydrogen at a transition metal surface.Comment: 15 pages, 9 figures, subm. to Phys. Rev.

Epidemiologic analyses with error-prone exposures: review of current practice and recommendations.

PURPOSE: Variables in observational studies are commonly subject to measurement error, but the impact of such errors is frequently ignored. As part of the STRengthening Analytical Thinking for Observational Studies Initiative, a task group on measurement error and misclassification seeks to describe the current practice for acknowledging and addressing measurement error. METHODS: Task group on measurement error and misclassification conducted a literature survey of four types of research studies that are typically impacted by exposure measurement error: (1) dietary intake cohort studies, (2) dietary intake population surveys, (3) physical activity cohort studies, and (4) air pollution cohort studies. RESULTS: The survey revealed that while researchers were generally aware that measurement error affected their studies, very few adjusted their analysis for the error. Most articles provided incomplete discussion of the potential effects of measurement error on their results. Regression calibration was the most widely used method of adjustment. CONCLUSIONS: Methods to correct for measurement error are available but require additional data regarding the error structure. There is a great need to incorporate such data collection within study designs and improve the analytical approach. Increased efforts by investigators, editors, and reviewers are needed to improve presentation of research when data are subject to error

Linear low-dose extrapolation for noncancer health effects is the exception, not the rule

The nature of the exposure-response relationship has a profound influence on risk analyses. Several arguments have been proffered as to why all exposure-response relationships for both cancer and noncarcinogenic end-points should be assumed to be linear at low doses. We focused on three arguments that have been put forth for noncarcinogens. First, the general “additivity-to-background” argument proposes that if an agent enhances an already existing disease-causing process, then even small exposures increase disease incidence in a linear manner. This only holds if it is related to a specific mode of action that has nonuniversal properties—properties that would not be expected for most noncancer effects. Second, the “heterogeneity in the population” argument states that variations in sensitivity among members ofthe target population tend to “flatten out and linearize” the exposure-response curve, but this actually only tends to broaden, not linearize, the dose-response relationship. Third, it has been argued that a review of epidemiological evidence shows linear or no-threshold effects at low exposures in humans, despite nonlinear exposure-response in the experimental dose range in animal testing for similar endpoints. It is more likely that this is attributable to exposure measurement error rather than a true non-threshold association. Assuming that every chemical is toxic at high exposures and linear at low exposures does not comport to modern-day scientific knowledge of biology. There is no compelling evidence-based justification for a general low-exposure linearity; rather, case-specific mechanistic arguments are needed

Psychodynamik medikalisierter Beziehungen

Konsensuskonferenzen in der Medizin tragen das zu einem bestimmten Zeitpunkt verfügbare Wissen über eine Krankheit zusammen, um Empfehlungen zu formulieren, wie sie erfolgreich diagnostiziert und therapiert werden kann. Für die Aufmerksamkeits und/oder Hyperaktivitätsstörung bei Kindern und Jugendlichen haben entsprechende Bemühungen dazu geführt, einen aufwendigen Diagnoseprozess zu verlangen, der die gesamte Lebenswelt der auffälligen Kinder und Jugendlichen in die Beobachtung einbezieht und Vorsicht walten lässt, um Unaufmerksamkeit, Impulsivität und Hyperaktivität nicht vorschnell als Symptome einer psychischen Störung zu beurteilen (Remschmidt, 2005). Ein solcher Aufwand ist nicht zuletzt deshalb notwendig, weil die Symptomdiagnose einer AD(H)S auf Urteilen sozialer Wahrnehmung beruht, die immer Normalitätsvorstellungen enthalten, die unterschiedlich ausfallen können. Eine andere Möglichkeit der Objektivierung gibt es nicht. Was die Therapie der AD(H)S betrifft, so gilt es inzwischen als Behandlungsstandard, sich nicht auf die Verordnung von Medikamenten zu beschränken, weil eine solche Beschränkung die Ätiologie der Symptome ignoriert. Wenn eine Medikation nach sorgfältiger Prüfung indiziert erscheint, sollte sie gegebenenfalls von psychotherapeutischen, psychoedukativen, ergotherapeutischen, logopädischen, pädagogischen oder anderen geeigneten nichtmedikamentösen Unterstützungen flankiert werden. Ohne eine solche Flankierung wird den Betroffenen die Entwicklung eines angemessenen Selbstverständnisses vorenthalten

Geschlechterstereotype und Geschlechterrollen

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