Characterization and tracking of the three-dimensional translational motion and rotation of single nanoparticles using a fiber-based microcavity with high finesse

Sophisticated new sensor techniques have to be developed to enable the detection of the temporal dynamics of single nanoparticles and molecules. Some of the new microscopy techniques are based on nanoparticle labeling, achieving high sensitivity on the single nanometer scale, but also changing the nanoparticle\u27s natural behavior. In this work, a fiber-based Fabry-Pérot (FP) microcavity with high finesse is presented, which allows the detection of unlabeled nanoparticles. Single nanoparticle resolution is achieved by forcing the light to thousands of round trips between two high-reflective mirrors of micrometer size and consequently enhancing the interaction between light and nanoparticle. So far, fiber-based FP cavities in air, vacuum and liquid helium have been reported in the past. In order to enable single nanoparticle measurements in liquids, two different microfluidic channels are demonstrated. Both channels allow an easy integration of the fiber-based FP cavity, provide a controllable laminar flow, and the measurement of small sample volumes. Furthermore the microfluidic channel and the integrated FP cavity are embedded in a sensing platform, that provides a high passive stability of $\sim1$pm and a low root-mean-square measurement noise of $0.39$pm. Combined with a high Cooperativity of the FP cavity in water of $C\sim Q\lambda_0^3/({n_{\mathrm{m}}^3 V_{\mathrm{m}}})=2.1\cdot10^4$ single SiO$_2$ nanospheres with a hydrodynamic radius down to $11.7$nm can already be detected. In this work, it is shown that the FP cavity allows the detection of hundreds of single SiO$_2$ nanosphere transit events within a few hours. From the derived statistical data, the SiO$_2$ nanosphere\u27s mean polarizability, as well as the mean effective refractive index, are deduced. Here, the first important finding is the detection of the nanosphere\u27s expanded size in pure water originating from a hydrate shell. This allows the estimation of the mean thickness as well as the mean refractive index of the hydrate shell of different SiO$_2$ nanosphere samples. Besides, the effect of salt on the hydrate shell is investigated. Already small salt concentrations presumably lead to a suppression of the formation of the hydrate shell and give indications of the significantly lower polarizability of the bare nanosphere. Furthermore, by improving the measurement time resolution, the polarizability of a single SiO$_2$ nanosphere is determined. In addition, the autocorrelation of the dispersive signal of several SiO$_2$ nanosphere transit events is compared with the theoretical numerical autocorrelation of a punctiform nanosphere and the Monte Carlo simulated autocorrelation of several nanosphere transit events with expanded size. As a result, a purely diffusive motion is identified. Completely new is the detection of the three-dimensional Brownian motion of a single nanosphere with a microcavity. By the simultaneous measurement of the dispersive shifts of the fundamental and two higher-order transverse modes, the three-dimensional coordinate of the nanosphere can be derived with a high spatial resolution of $8$nm and a high temporal resolution of $0.3$ms. This is first analyzed by simulations and then demonstrated with measured signals. From the three-dimensional track, the nanosphere\u27s diffusivity, as well as its hydrodynamic radius, is deduced. The rotational diffusion of single anisotropically shaped nanoparticles is measured by the polarization-split fundamental mode with a high temporal resolution of $0.07$ms. Already nanospheres with a specified roundness of >0.98 can be investigated in their rotational diffusion, showing that this detection method is highly sensitive. The presented FP microcavity already achieves a sensitivity, which allows the detection of different molecules like viruses, ribosomes, and exosomes. Therefore, it is a promising candidate for a future detection of the dynamics of single, unlabeled molecules with a small molecular mass

Le potentiel de valorisation des cinémas de Sierre par l'association Ecran Total

L’objectif principal de cette étude est d’amener des réponses concrètes à la question de recherche « comment valoriser à long terme les cinémas de Sierre afin d’attirer et de fidéliser un public plus nombreux et d’atteindre les objectifs de rentabilité ?», dans le but de maintenir une politique culturelle pour la Ville de Sierre et d’assurer la pérennité des cinémas de la ville. Une des solutions envisagées est la fidélisation de la clientèle au travers divers événements mis en place par l’association Ecran Total nouvellement crée (2013). Pour réaliser cette étude, trois axes analyses ont été choisis. Premièrement, une analyse de marché a été effectuée afin de dépeindre la situation dans laquelle le marché du cinéma évolue et d’observer les éventuelles menaces. Puis, une analyse concurrentielle de marché a permis d’entrevoir les stratégies des cinémas romands ainsi que celles des cinémas en dehors de la Suisse, concernant les animations et les événements organisés afin d’affiner le business modèle des cinémas sierrois. Pour finir, des entretiens qualitatifs ont été effectués avec les différents acteurs, internes et externes, des cinémas sierrois, afin de positionner ces derniers par rapport aux autres cinémas. Les résultats de cette étude ont permis de comprendre quelle était la situation actuelle des cinémas sierrois et quelles pourraient être les pistes d’amélioration envisageables afin d’attirer et de fidéliser la clientèle. De ces résultats, un plan de communication comprenant diverses suggestions de scénarii d’événements a pu être décrit. L’association Ecran Total est libre de s’en inspirer afin de proposer un ou plusieurs nouveaux événements dans les salles sierroises

Developing intercultural language learning textbooks: Methodological trends, engaging with the intercultural construct, and personal reflections on the process

Historically, textbook development for languages education has reflected methodological trends in languages learning, from grammar-translation methods used in the first half of the twentieth century, through audio-lingual, notionalfunctional, communicative language learning and other methodological paradigms. A current methodological trend – arguably more an ‘orientation’ to languages learning than a ‘method’ – involves developing ‘intercultural’ perspectives. In this orientation,learners are invited to constantly consider the interrelationship of language and culture; what this interplay means within variable cultural contexts; to work ‘across and between’ the languages they know and are learning; and to think reflexively on how developing understandings of new languages and cultures ultimately affects them as individuals and members of communities. The authors have been researching and working with intercultural language learning over a number of years. In response to the need for resources reflecting this orientation and their own desire to see how this might be realised in commercially available materials (textbooks and online support), Lesley Harbon, Michelle Kohler and Anne-Marie Morgan have developed a textbook series with an intercultural orientation for Australian middle years learners of Indonesian. The journey in developing these materials has raised many questions and challenges, including considering how a diversity of perspectives about languages and cultures might be represented and catered for in ‘static’ resources. This article situates the current trend towards intercultural language learning within an historical context of textbook development and language teaching methodologies; explores current understandings of the intercultural construct and considers how this understanding has influenced the writing of the series; and provides reflections on the complexities and challenges of development of this resource

Data of national dishes in the developed and developing countries in the world : their similarity and trade flows

This paper presents a database that includes information on national recipes and their ingredients for 171 countries, measures for food taste similarities between all 171 countries as well as bilateral migration and agro-food trade data for 5 years. The database can be used for analyzing e.g., the relation between food preferences and international trade or food preferences and health outcomes (e.g., obesity) across countries

Urbanicity and Mental Health in Europe: A Systematic Review

Urbanicity has been described as a risk factor for mental disorders. Findings differ across countries and psychiatric outcomes. Our aim was to systematically review quantitative studies of the relationship between urbanicity and prevalent mental disorders in Europe. EBSCOhost and PubMed databases were searched for epidemiological studies of European populations, published in English between January 2002 and October 2012, using the combination of keywords (urban* OR environment*) AND (mental health OR mental disorder OR psych*). The eleven studies included in the review used studies used different measures of urbanicity. The types of mental disorders most often examined, on which we focus in the review, were mood and anxiety disorders, psychosis, and substance use disorders. Urbanicity was associated with mental health. Seven out of nine studies reported more mood and anxiety disorders in some of the urban areas compared to rural areas. Two out of three studies indicated higher rates of psychosis in some more urbanised areas. Four out of six studies found more substance abuse with increased urbanicity. The same studies neither found any evidence for a relationship between urbanicity and mental disorders in several instances. Living in an urban environment in Europe can be a risk factor for mood and anxiety disorders, psychotic disorders, and substance abuse. More research is needed to understand which urban environment characteristics cause mental disorders

The impact of agricultural subsidies on obesity

Farm subsidies are on the rise. Such subsidies can be paid either through transfers from tax payers (PSE) or at the expense of consumers (CSE) or both. As farm subsidies may have an influence on food prices, it makes certain farm commodities more abundant and therefore cheaper. This paper aims to investigate if such subsidies can contribute in explaining rising obesity rates worldwide. We use data on farm subsidies and obesity data from OECD and FAO and distinguish two models to investigate the different effects: on the one hand on overweight (BMI above 25 to 30) and on the other hand on obesity (BMI above 30). Regression analysis shows that farm subsidies may be too low to have an effect on overweight or obesity and conclude that rising obesity is probably better fought on a national level instead trying to fight it on a cross-country level

Community Seismic Network

The article describes the design of the Community Seismic Network, which is a dense open seismic network based on low cost sensors. The inputs are from sensors hosted by volunteers from the community by direct connection to their personal computers, or through sensors built into mobile devices. The server is cloud-based for robustness and to dynamically handle the load of impulsive earthquake events. The main product of the network is a map of peak acceleration, delivered within seconds of the ground shaking. The lateral variations in the level of shaking will be valuable to first responders, and the waveform information from a dense network will allow detailed mapping of the rupture process. Sensors in buildings may be useful for monitoring the state-of-health of the structure after major shaking