Networks in Nigeria: A pilot study on network characteristics and their relation with life satisfaction in a Nigerian sample

Social relationships are a central determinant of life satisfaction. The collectivity of individual social relationships form a social network. This study examines such networks in a Nigerian sample (N = 108). Network size, proportions of positive and negative relationships within those networks, and structural characteristics (e.g., network centrality) were assessed. Furthermore, network characteristics were examined concerning their association with life satisfaction. Results indicate differential relations of network characteristics with life satisfaction. Results are discussed in terms of (1) cross-cultural assessment of network characteristics, (2) life satisfaction as related to social structural characteristics, and (3) differential associations between network types and different aspects of life satisfaction

The Lady in Pink: Dress and the Enigma of Gendered Space in Marcel Proust\u27s Fiction

A study of the role of clothing as central to issues of characterization, description and historical reference in Marcel Proust\u27s A la recherche du temps perdu. Focus on Odette de Crécy, one of the central characters in the novel, a courtesan who becomes the wife of Charles Swann but who first captivates the narrator\u27s imagination when, as a child, he briefly sees her as a Lady in Pink. Odette\u27s role as a fashionable woman, as one of the best-dressed women in Parisian society, gives unity to her character. The description of her clothing, however, not only provides the occasion for an accurate recreation of contemporary dress codes. The links between clothing and a woman\u27s body are explicitly explored in creating the character of Odette. Her femininity is defined specifically in terms of surfaces and objects and her personality seems to assume its reality from costume. Dress not only encloses her lovely appearance; it gives substance to her person and order to her life. Through the agency of dress this ordinary, even vulgar woman rises above her condition and enters a world of passion and poetry

A model study of strong correlations in Hund metals

For a long time strong electronic correlations in metals have mainly been associated with Mottness, the proximity to a Mott metal-insulator transition (MIT), where large Coulomb interactions induce the localization of charges. However, triggered by the discovery of the iron-based superconductors about ten years ago, it was realized that multi-orbital materials with only moderate Coulomb but sizeable Hund’s rule interactions – so-called Hund metals – allow for a distinct screening mechanism towards strong correlations: Hundness. Here, Hund’s rule constrains the spin rather than the charge dynamics. This discovery led to a vividly debated fundamental issue in the field of strongly correlated condensed matter systems, which is the main topic of the present thesis: what is the origin of strong correlations in the normal phase of Hund metals, Mottness or Hundness? And what are their decisive fingerprints? The goal of this dissertation is twofold. First, we present and advance our method: the numerical renormalization group (NRG) as viable real-frequency multi-band impurity solver for dynamical mean-field theory (DMFT), a common approach to tackle strongly correlated systems. Second, we apply DMFT+NRG to shed light on the Hund-metal problem raised above. In the first part of this thesis we present our state-of-the-art NRG solver, which offers direct access to data with unprecedented real-frequency spectral resolution at arbitrarily low energies and temperatures in contrast to commonly used Quantum Monte Carlo solvers. It is based on matrix product states and exploits non-abelian symmetries to reduce numerical costs. In the case of orbital symmetry, this allows us to treat multi-band models with more than two bands, and thus to tackle the Hund-metal problem for the first time with NRG. For multi-band models without orbital symmetry, an “interleaved” scheme of NRG (iNRG) was recently developed, dramatically increasing the numerical efficiency. Remarkably, the accuracy of iNRG is comparable to standard NRG, as we reveal in a detailed study. This finding establishes iNRG as a promising DMFT solver for material-specific model simulations. In the second part of this thesis we study a minimal toy model for Hund metals with DMFT+NRG, the orbital-symmetric three-band Hubbard-Hund model (3HHM) close to a lattice filling of 1/3. Our major insight is “spin-orbital separation” (SOS), a Hund’s-ruleinduced two-stage Kondo-type screening process, in which orbital screening occurs at much higher energies than spin screening. In Hund metals, i.e. far from a MIT phase boundary, SOS thus causes large electron masses by strongly reducing the coherence scale below which a Fermi liquid is formed. Further, it opens up a broad incoherent and strongly particle-hole asymmetric intermediate energy regime that reaches up to bare excitation scales. This SOS regime shows fractional power-law behavior and is characterized by resilient “Hund quasiparticles” with itinerant orbital degrees of freedom coupled non-trivially to quasi-free large spins. At zero temperature, the local density of states exhibits a two-tier quasiparticle peak on top of a broad incoherent background. In contrast, in Mott-correlated metals, i.e. close to the MIT phase boundary, the SOS regime becomes negligibly small and the Hubbard bands are well separated. These findings lead to distinct signatures of Hundness and Mottness in the temperature dependence of ARPES spectra, static local susceptibilities, resistivity, thermopower and entropy, many of which were also found in realistic simulations of the archetypal Hund- and Mott-correlated materials, Sr2RuO4 and V2O3. In summary, we provide evidence that and elucidate how Hundness evokes strong correlation effects in Hund metals. This might help to better interpret experimental results and guide superconducting theories

Prevalence of Vancomycin-Resistant Enterococci colonization and its risk factors in chronic hemodialysis patients in Shiraz, Iran

<p>Abstract</p> <p>Background</p> <p>Vancomycin-resistant entrococci (VRE) are increasing in prevalence at many institutions, and are often reported in dialysis patients. The aim of this cross-sectional prevalence study was to determine the prevalence and risk factors of VRE colonization in chronic hemodialysis patients in two hemodialysis centers in Shiraz, Iran.</p> <p>Methods</p> <p>Rectal swabs were obtained from all consenting patients and were streaked on the surface of Cephalexin-aztreonam-arabinose agar (CAA) and incubated at 37°C in air for 24 h. The vancomycin susceptibility of each isolate was confirmed by disk susceptibility testing. The MICs of vancomycin and teicoplanin were confirmed by the E test. To identify risk factors, a questionnaire was completed for all the studied patients and the data of VRE positive and negative groups were compared using Man-Withney U test for continues data and the Fisher exact test for categorical data.</p> <p>Results</p> <p>Of 146 patients investigated, 9 (6.2%) were positive for VRE. All VRE strains were genotypically distinguishable. Risk factors for a VRE-positive culture were "antimicrobial receipt within 2 months before culture" (P = 0.003) and "hospitalization during previous year" (P = 0.016).</p> <p>Conclusion</p> <p>VRE colonization is an under-recognized problem among chronic dialysis patients in Iran. VRE colonization is associated with antibiotic consumption and hospitalization.</p

A model study of strong correlations in Hund metals

For a long time strong electronic correlations in metals have mainly been associated with Mottness, the proximity to a Mott metal-insulator transition (MIT), where large Coulomb interactions induce the localization of charges. However, triggered by the discovery of the iron-based superconductors about ten years ago, it was realized that multi-orbital materials with only moderate Coulomb but sizeable Hund’s rule interactions – so-called Hund metals – allow for a distinct screening mechanism towards strong correlations: Hundness. Here, Hund’s rule constrains the spin rather than the charge dynamics. This discovery led to a vividly debated fundamental issue in the field of strongly correlated condensed matter systems, which is the main topic of the present thesis: what is the origin of strong correlations in the normal phase of Hund metals, Mottness or Hundness? And what are their decisive fingerprints? The goal of this dissertation is twofold. First, we present and advance our method: the numerical renormalization group (NRG) as viable real-frequency multi-band impurity solver for dynamical mean-field theory (DMFT), a common approach to tackle strongly correlated systems. Second, we apply DMFT+NRG to shed light on the Hund-metal problem raised above. In the first part of this thesis we present our state-of-the-art NRG solver, which offers direct access to data with unprecedented real-frequency spectral resolution at arbitrarily low energies and temperatures in contrast to commonly used Quantum Monte Carlo solvers. It is based on matrix product states and exploits non-abelian symmetries to reduce numerical costs. In the case of orbital symmetry, this allows us to treat multi-band models with more than two bands, and thus to tackle the Hund-metal problem for the first time with NRG. For multi-band models without orbital symmetry, an “interleaved” scheme of NRG (iNRG) was recently developed, dramatically increasing the numerical efficiency. Remarkably, the accuracy of iNRG is comparable to standard NRG, as we reveal in a detailed study. This finding establishes iNRG as a promising DMFT solver for material-specific model simulations. In the second part of this thesis we study a minimal toy model for Hund metals with DMFT+NRG, the orbital-symmetric three-band Hubbard-Hund model (3HHM) close to a lattice filling of 1/3. Our major insight is “spin-orbital separation” (SOS), a Hund’s-ruleinduced two-stage Kondo-type screening process, in which orbital screening occurs at much higher energies than spin screening. In Hund metals, i.e. far from a MIT phase boundary, SOS thus causes large electron masses by strongly reducing the coherence scale below which a Fermi liquid is formed. Further, it opens up a broad incoherent and strongly particle-hole asymmetric intermediate energy regime that reaches up to bare excitation scales. This SOS regime shows fractional power-law behavior and is characterized by resilient “Hund quasiparticles” with itinerant orbital degrees of freedom coupled non-trivially to quasi-free large spins. At zero temperature, the local density of states exhibits a two-tier quasiparticle peak on top of a broad incoherent background. In contrast, in Mott-correlated metals, i.e. close to the MIT phase boundary, the SOS regime becomes negligibly small and the Hubbard bands are well separated. These findings lead to distinct signatures of Hundness and Mottness in the temperature dependence of ARPES spectra, static local susceptibilities, resistivity, thermopower and entropy, many of which were also found in realistic simulations of the archetypal Hund- and Mott-correlated materials, Sr2RuO4 and V2O3. In summary, we provide evidence that and elucidate how Hundness evokes strong correlation effects in Hund metals. This might help to better interpret experimental results and guide superconducting theories

The antimicrobial effect of Octenidine-dihydrochloride coated polymer tracheotomy tubes on Staphylococcus aureus and Pseudomonas aeruginosa colonisation

<p>Abstract</p> <p>Background</p> <p>The surface of polymeric tracheotomy tubes is a favourable environment for biofilm formation and therefore represents a potential risk factor for the development of pneumonia after tracheotomy. The aim of this <it>in-vitro </it>study was to develop octenidine-dihydrochloride (OCT) coated polymer tracheotomy tubes and investigate any effects on <it>Staphylococcus (S.) aureus </it>and <it>Pseudomonas (P.) aeruginosa </it>colonization. Additionally the resistance of the OCT coating was tested using reprocessing procedures like brushing, rinsing and disinfection with glutaraldehyde</p> <p>Results</p> <p><it>Contamination with S. aureus</it>: Before any reprocessing, OCT coated tracheotomy tubes were colonized with 10³cfu/ml and uncoated tracheotomy tubes with 10⁵cfu/ml (P = 0.045). After reprocessing, no differences in bacterial concentration between modified and conventional tubes were observed.</p> <p><it>Contamination with P. aeruginosa</it>: Before reprocessing, OCT coated tubes were colonized with 10⁶cfu/ml and uncoated tubes with 10⁷cfu/ml (P = 0.006). After reprocessing, no significant differences were observed.</p> <p>Conclusion</p> <p>OCT coating initially inhibits <it>S. aureus </it>and <it>P. aeruginosa </it>colonisation on tracheotomy tubes. This effect, however, vanishes quickly after reprocessing of the tubes due to poor adhesive properties of the antimicrobial compound. Despite the known antimicrobial effect of OCT, its use for antimicrobial coating of tracheotomy tubes is limited unless methods are developed to allow sustained attachment to the tube.</p

Evaluating a City Lab Process in Mannheim's district Neckarstadt-West: Three main challenges for the evaluation

During the last few years, city labs have emerged as promising formats to address transformative change. The aim of these formats often is to create collaborative spaces in which different stakeholders can jointly experiment with novel solutions for certain problems. While city labs start to establish transdisciplinary research settings, evaluating the effects of a city lab still brings about several chal- lenges. In this contribution, we reflect on three main challenges that emerged in the course of evaluating a city lab in Mannheim’s district Neckarstadt-West. The city lab was conducted as part of the research project SONNET (Social Innovation in Energy Transitions) and aimed to encourage social innovation in energy and thereby enable local energy transition. In the context of evaluating the city lab, we identified three main challenges that were related to a) evaluating an ongoing and open process, b) external shocks (especially in the context of the COVID-19 pandemic) and c) evaluating new forms of innovation under the concept of ‘social innovation’. The main achievement of this evaluation was to trace the process of a city lab and identify changes in objectives as well as the engagement of different stakeholder groups. However, an evaluation of the city lab’s outcomes remains challenging due to the openness of the process. This suggests rethinking linear evaluation models in favour of co-designing evaluation criteria in the course of the city lab process

Energy efficiency as interplay between technical installations and social actors: Barriers to the efficient operation of complex heating systems

Ein energieeffizienter Betrieb von Heizungsanlagen wird als Beitrag zum Erreichen der Klimaschutzziele immer bedeutsamer. Da zukunftsweisende Entwicklungen primär technischen Innovationen zugeschrieben werden, wurden in den vergangenen Jahren in vielen Gebäuden moderne Anlagen installiert. In der Praxis zeigt sich jedoch, dass die prognostizierten Einsparungen meist nicht erreicht werden. Anhand der empirischen Ergebnisse des Forschungsprojektes ENGITO wird deutlich, dass dies vielfach auf soziale Hemmnisse zurückzuführen ist, die bislang zu wenig berücksichtigt werden. Im Folgenden wird auf typische Hemmnisse für den effizienten Anlagenbetrieb eingegangen, wobei deutlich wird, dass bei der Gestaltung zukünftiger Energiesysteme arbeitsorganisatorische Aspekte eine grundlegende Rolle spielen. Energieeffizienz wird dabei aus soziotechnischer Perspektive betrachtet und als Ergebnis des Zusammenspiels technischer Voraussetzungen und sozialer Akteure verstanden.In order to achieve climate protection targets, energy-efficient operation of heating systems is of central importance to achieving climate protection targets. So far, innovation of the energy system has primarily been attributed to technological innovation. Therefore, modern energy systems have been installed in many buildings over the last two decades. However, in practice, predicted savings are usually not achieved. The empirical results of the ENGITO project show that this is often due to social barriers, which have hardly been considered so far. The article addresses typical barriers to efficient operation of heating systems and shows that work organization and distribution of responsibility play an important role in shaping future energy systems. In this article, energy efficiency is viewed from a socio-technical perspective and understood as interplay between technological installations and social actors