Electron-hole spectra created by adsorption on metals from density-functional theory

Non-adiabaticity in adsorption on metal surfaces gives rise to a number of measurable effects, such as chemicurrents and exo-electron emission. Here we present a quantitative theory of chemicurrents on the basis of ground-state density-functional theory (DFT) calculations of the effective electronic potential and the Kohn-Sham band structure. Excitation probabilities are calculated both for electron-hole pairs and for electrons and holes separately from first-order time-dependent perturbation theory. This is accomplished by evaluating the matrix elements (between Kohn-Sham states) of the rate of change of the effective electronic potential between subsequent (static) DFT calculations. Our approach is related to the theory of electronic friction, but allows for direct access to the excitation spectra. The method is applied to adsorption of atomic hydrogen isotopes on the Al(111) surface. The results are compatible with the available experimental data (for noble metal surfaces); in particular, the observed isotope effect in H versus D adsorption is described by the present theory. Moreover, the results are in qualitative agreement with computationally elaborate calculations of the full dynamics within time-dependent density-functional theory, with the notable exception of effects due to the spin dynamics. Being a perturbational approach, the method proposed here is simple enough to be applied to a wide class of adsorbates and surfaces, while at the same time allowing us to extract system-specific information.Comment: 23 pages, 9 figures, accepted for publication in Phys. Rev. B, http://prb.aps.org/, v2: some major improvements, plus correction of minor error

Nucleated dewetting in supported ultra-thin liquid films with hydrodynamic slip

This study reveals the influence of the surface energy and solid/liquid boundary condition on the breakup mechanism of dewetting ultra-thin polymer films. Using silane self-assembled monolayers, SiO$_2$ substrates are rendered hydrophobic and provide a strong slip rather than a no-slip solid/liquid boundary condition. On undergoing these changes, the thin-film breakup morphology changes dramatically -- from a spinodal mechanism to a breakup which is governed by nucleation and growth. The experiments reveal a dependence of the hole density on film thickness and temperature. The combination of lowered surface energy and hydrodynamic slip brings the studied system closer to the conditions encountered in bursting unsupported films. As for unsupported polymer films, a critical nucleus size is inferred from a free energy model. This critical nucleus size is supported by the film breakup observed in the experiments using high speed \emph{in situ} atomic force microscopy.Comment: 8 pages, 9 figures, including supplementary materia

Intracellular rols7 mRNA localization and the importance of Barren for mitosis in the embryonic myogenesis of Drosophila melanogaster

The body wall musculature of the D. melanogaster larva is a highly ordered assembly of striated myotubes that are formed by fusion of myoblasts, much like the skeletal muscle fibres of vertebrates. In this study, the embryonic development of this musculature is used as a genetic model system for myogenesis, muscle regeneration and related processes. Rols7 is a crucial protein in the signal transduction chain that controls the Actin filament branching necessary for myoblast fusion. In somatic muscle founder cells, the rols7 mRNA shows intracellular localization into one or more patches near the cell surface. This thesis demonstrates that the rols7 transcript’s 3’ untranslated region is necessary for its localization. A reporter mRNA with this trailer region as well as the 5’ untranslated region gets intracellularly localized in a way seemingly identical to the wild type pattern, even in the absence of native rols transcripts. The rols7 mRNA is shown to be intracellularly localized in the circular and longitudinal visceral muscle founder cells as well; in the latter it forms spots close to the tips of the spindle-shaped cells, near the expected sites of cell-cell fusion. At least for this latter cell type it can be suspected that rols7 mRNA localisation facilitates protein localisation and eventually myoblast fusion by preforming the Rols7 protein’s distribution pattern. In search of previously unknown factors involved in myogenesis, the muscle phenotype of the EMS-induced mutant line E831 is analyzed. As the cause for the disturbed arrangement of the embryonic body wall musculature a nonsense mutation of the Condensin subunit barren is identified. Cap-G, another Condensin subunit, is found to show a phenotype very similar to that of barren. While in a barren mutant both muscle founder cells and fusion competent myoblasts seem to get specified, muscle identity genes are expressed irregularly in a manner that corresponds to the perturbation of the muscle pattern. In every cell, the Condensin complex fulfills a variety of essential functions. To help clarify whether the muscle phenotype is connected to Condensin’s regulatory role during interphase or its function in chromosome segregation during mitosis, the time point at which Barren is needed in the musculature has to be identified. To this end, the Gal4-UAS system is used to express a barren rescue construct. Gal4 drivers are found to rescue the phenotype only if they express Barren considerably before the final cell division that gives rise to the muscle founder cells. This finding suggests that the muscle phenotype is caused by a mitotic defect. The mechanism behind the loss of muscle identity appears to be a phenomenon related to the genomic instability of cancer cell lines

Promoting medical competencies through international exchange programs: benefits on communication and effective doctor-patient relationships

Background: Universities are increasingly organizing international exchange programs to meet the requirements of growing globalisation in the field of health care. Analyses based on the programs' fundamental theoretical background are needed to confirm the learning value for participants. This study investigated the extent of sociocultural learning in an exchange program and how sociocultural learning affects the acquisition of domain-specific competencies. Methods: Sociocultural learning theories were applied to study the learning effect for German medical students from the LMU Munich, Munich, Germany, of participation in the medical exchange program with Jimma University, Jimma, Ethiopia. First, we performed a qualitative study consisting of interviews with five of the first program participants. The results were used to develop a questionnaire for the subsequent, quantitative study, in which 29 program participants and 23 matched controls performed self-assessments of competencies as defined in the Tuning Project for Health Professionals. The two interrelated studies were combined to answer three different research questions. Results: The participants rated their competence significantly higher than the control group in the fields of doctor-patient relationships and communication in a medical context. Participant responses in the two interrelated studies supported the link between the findings and the suggested theoretical background. Conclusion: Overall, we found that the exchange program affected the areas of doctor-patient relationships and effective communication in a medical context. Vygotsky's sociocultural learning theory contributed to explaining the learning mechanisms of the exchange program

Recent Developments in Jurisdiction Regarding European Labour and Social Law

Niniejszy komentarz dotyczy wybranych istotnych orzeczeń Europejskiego Trybunału Sprawiedliwości odnośnie do prawa pracy i prawa socjalnego wydanych w 2012 i 2013 roku. W swoim charakterystycznym obecnie stylu Europejski Trybunał Sprawiedliwości ponownie mocno ingerował w prawo krajowe państw członkowskich. Mimo że Trybunał zachował w zasadzie swoją ostatnią linię orzecznictwa, przegląd jego orzeczeń nie może być przeceniany

A 490 GHz planar circuit balanced Nb-Al2_\mathbf{2}O3_{\mathbf{3}}-Nb quasiparticle mixer for radio astronomy: Application to quantitative local oscillator noise determination

This article presents a heterodyne experiment which uses a 380-520 GHz planar circuit balanced Nb-$\mathrm{Al_2O_3}$-Nb superconductor-insulator-superconductor (SIS) quasiparticle mixer with 4-8 GHz instantaneous intermediate frequency (IF) bandwidth to quantitatively determine local oscillator (LO) noise. A balanced mixer is a unique tool to separate noise at the mixer's LO port from other noise sources. This is not possible in single-ended mixers. The antisymmetric IV characteristic of a SIS mixer further helps to simplify the measurements. The double-sideband receiver sensitivity of the balanced mixer is 2-4 times the quantum noise limit $h\nu/k_B$ over the measured frequencies with a maximum LO noise rejection of 15 dB. This work presents independent measurements with three different LO sources that produce the reference frequency but also an amount of near-carrier noise power which is quantified in the experiment as a function of the LO and IF frequency in terms of an equivalent noise temperature $T_{LO}$. In a second experiment we use only one of two SIS mixers of the balanced mixer chip, in order to verify the influence of near-carrier LO noise power on a single-ended heterodyne mixer measurement. We find an IF frequency dependence of near-carrier LO noise power. The frequency-resolved IF noise temperature slope is flat or slightly negative for the single-ended mixer. This is in contrast to the IF slope of the balanced mixer itself which is positive due to the expected IF roll-off of the mixer. This indicates a higher noise level closer to the LO's carrier frequency. Our findings imply that near-carrier LO noise has the largest impact on the sensitivity of a receiver system which uses mixers with a low IF band, for example superconducting hot-electron bolometer (HEB) mixers.Comment: 13 pages, 8 figures, 2 tables, see manuscript for complete abstrac

Quantification of the Adhesion Strength of Candida albicans to Tooth Enamel

Caries is one of the most prevalent diseases worldwide, which is caused by the degradation of the tooth enamel surface. In earlier research the opportunistic pathogen Candida albicans has been associated with the formation of caries in children. Colonization of teeth by C. albicans starts with the initial adhesion of individual yeast cells to the tooth enamel surface. In this study, we visualized the initial colonization of C. albicans yeast cells on pellicle-covered enamel by scanning electron microscopy. To quantitatively unravel the initial adhesion strength, we applied fluidic force microscopy-based single-cell force spectroscopy to examine the key adhesion parameters adhesion force, rupture length and de-adhesion work. We analyzed single saliva-treated or untreated yeast cells on tooth enamel specimens with or without salivary pellicle. Under all tested conditions, adhesion forces in the lower nanonewton range were determined. Furthermore, we have found that all adhesion parameters were enhanced on the pellicle-covered compared to the uncovered enamel. Our data suggest that initial adhesion occurs through a strong interaction between yeast cell wall-associated adhesins and the salivary pellicle. Future SCFS studies may show whether specific management of the salivary pellicle reduces the adhesion of C. albicans on teeth and thus contributes to caries prophylaxis

Gesundheits-Apps. Innovationsanalyse

Fast täglich kommen neue Gesundheits-Apps auf den Markt. Die Angebote reichen von Fitness- und Ernährungsinformationen bis hin zur Unterstützung bei gesundheitlicher Einschränkung und Krankheit. Gesundheits-Apps begleiten dabei das alltägliche Gesundheitshandeln von Menschen sehr individuell. Dem Markt für Gesundheits-Apps fehlt jedoch eine zuverlässige Qualitätskontrolle, die insbesondere den Datenschutz berücksichtigt. Apps (Kurzform für Application Software) bestimmen zunehmend den gesellschaftlichen Lebensalltag. Immer öfter nutzen Menschen Apps auch mit dem Ziel, positiv auf ihre Gesundheit einzuwirken. Die Apps eröffnen vor dem Hintergrund der Leistungssteigerung bei Smartphones und Wearables mit stetig neuen Funktionalitäten Innovationspotenziale, indem sie alltägliche Formen des Gesundheitshandelns von Menschen individuell angepasst begleiten. Viele Nutzer gehen dabei jedoch sorglos mit ihren Gesundheitsdaten um. Ihnen ist nicht bewusst, dass ihre persönlichen Daten oft unzureichend gesichert sind. Problematisch sind vor allem die Umsetzung bzw. Kontrolle der Einhaltung der gesetzlichen Vorgaben durch die Anbieter von Gesundheits-Apps. Die TAB-Innovationsanalyse gibt einen Überblick über aktuelle technologische und ökonomische Entwicklungstrends von Gesundheits-Apps. Sie zeigt darüber hinaus gesellschaftliche Diskussionspunkte, Wertorientierungen sowie politische Handlungsoptionen als Grundlage für eine Einschätzung der Innovationspotenziale auf. Inhalt Zusammenfassung 9 I Einleitung 23 II Begrifflich-konzeptionelle Einordnung 27 1 Gesundheit 27 2 eHealth 29 3 mHealth 30 4 Gesundheits-Apps 31 III Technologische Funktionalität 35 1 Einordnung 35 2 Mobile Endgeräte 36 3 Sensoren 37 3.1 Definition und Typologie 37 3.2 Propriozeptive und exterozeptive Sensoren 39 3.3 Funksensoren 41 3.4 Zusammenwirken physikalisch-mechanischer Sensoren am Beispiel des Schlafverlaufs 41 4 Konzepte für die technische Integration und Weiterentwicklung von Gesundheits-Apps 43 4.1 Interoperabilität 43 4.2 Cloudcomputing 44 4.3 Künstliche Intelligenz und maschinelles Lernen 44 IV Kategorien von Gesundheits-Apps 47 1 Funktionale Kategorisierung 47 2 Nutzergruppenorientierte Kategorisierung 48 3 Anwendungsfeldorientierte Kategorisierung 49 4 Juristische Kategorisierung 50 V Marktentwicklung 53 1 Angebotsentwicklung 53 2 Geschäftsmodelle 55 3 Nachfrageentwicklung und Nutzergruppen 67 4 Gesundheits-Apps und Krankenkassen 73 4.1 Gesundheits-Apps von Krankenkassen: Status quo 73 4.2 Gesundheits-Apps in der Versorgung 74 4.3 Marktzugang für Gesundheits-Apps in der (Regel-)Versorgung 76 4.4 Gesundheits-Apps im Bonusprogramm 77 VI Gesundheits-Apps als soziale Innovation 81 1 Innovationsperspektiven 81 2 Gesundheitsbezogene Herausforderungen 82 3 Gesundheits-Apps als soziale Innovation 84 VII Gesellschaftliche Aspekte 87 1 Gesundheits-Apps als Ausdruck gesellschaftlichen Wandels 87 1.1 Selbstverdatung und Objektivierung der Körperwahrnehmung 88 1.2 Verschiebungen im Verständnis von Gesundheit 88 1.3 Daten mit Potenzial zur Kontrolle und rationalen Diskriminierung 89 1.4 Prävention und Eigenverantwortung für Gesundheit 90 2 Qualitätsmerkmale von Gesundheits-Apps 91 2.1 Qualität der derzeit auf dem Markt befindlichen Apps 92 2.2 Gebrauchstauglichkeit und Zielgruppenadäquatheit 92 2.3 Evidenzbasiertheit 94 2.4 Datenqualität 96 2.5 Nutzerorientierung 98 3 Rechtliche Aspekte von Gesundheits-Apps 100 3.1 Gesundheits-Apps in Abgrenzung zu Medizinprodukten 100 3.2 Gesundheits-Apps im nationalen und internationalen Recht 101 3.3 Europäische und internationale Datenschutzbezüge 112 VIII Ergebnisse des Stakeholder Panels 119 1 Onlinebefragung 120 2 Stakeholderworkshop 132 IX. Handlungsoptionen und Ausblick 135 1 Förderung von Gesundheitskompetenz 135 2 Durchsetzung von differenzierten Qualitätskriterien 137 3 Kontrolle der Umsetzung des Datenschutzes 139 4 Förderung des gesellschaftlichen Dialogs 141 5 Förderung gesellschaftlicher Innovation durch Gesundheits-Apps 142 Literatur 143 Anhang 155 1 Abbildungen 155 2 Tabellen 15