The small-angle neutron scattering instrument D33 at the Institut Laue-Langevin

in JOURNAL OF APPLIED CRYSTALLOGRAPHY (2016), 49

The D33 small-angle neutron scattering (SANS) instrument at the Institut Laue–Langevin (ILL) is the most recent SANS instrument to be built at the ILL. In a project beginning in 2005 and lasting seven ... [more ▼]

The D33 small-angle neutron scattering (SANS) instrument at the Institut Laue–Langevin (ILL) is the most recent SANS instrument to be built at the ILL. In a project beginning in 2005 and lasting seven years, the concept has been developed, and the instrument designed, manufactured and installed. D33 was commissioned with neutrons during the second half of 2012, fully entering the ILL user programme in 2013. The scientific case required that D33 should provide a wide dynamic range of measured scattering vector magnitude q, flexibility with regard to the instrument resolution, and the provision of polarized neutrons and 3He spin analysis to facilitate and expand studies in magnetism. In monochromatic mode, a velocity selector and a flexible system of inter-collimation apertures define the neutron beam. A double-chopper system enables a time-of-flight (TOF) mode of operation, allowing an enhanced dynamic q range (qmax/qmin) and a flexible wavelength resolution. Two large multitube detectors extend the dynamic q range further, giving qmax/qmin ’ 25 in monochromatic mode and a very large qmax/qmin > 1000 in TOF mode. The sample zone is large and flexible in configuration, accommodating complex and bulky sample environments, while the position of D33 is such as to allow high magnetic fields at the sample position. The instrument is of general purpose with a performance rivalling that of D22, and is well adapted for SANS studies in scientific disciplines as diverse as solution scattering in biology and soft matter and studies of physics, materials science and magnetism. This article provides a detailed technical description of D33 and its performance and characterization of the individual components, and serves as a technical reference for users of the instrument. [less ▲]

Surdoses et inégalités sociales. Mieux comprendre les décès liés à l’usage de drogues pour mieux agir

Book published by L'harmattan - Académia (2016)

Les abus de drogues posent d’importants défis en termes sociaux, économiques, de sécurité et de santé publique. Quel est le profil socio-économique des consommateurs ? Quelles sont les différentes ... [more ▼]

Les abus de drogues posent d’importants défis en termes sociaux, économiques, de sécurité et de santé publique. Quel est le profil socio-économique des consommateurs ? Quelles sont les différentes trajectoires familiales, professionnelles et sociales d’usagers de drogues victimes de surdose fatale ? Quel est l’impact des inégalités sociales dans la survenue de surdoses impliquant des drogues illicites? Quel rôle pourrait avoir la réduction des inégalités sociales ? Quel enjeu pour les stratégies de prévention et de réduction des risques ? Un ensemble de recherches originales menées au Luxembourg, s’appuyant sur des méthodologies innovantes et une revue de littérature scientifique abondante, ont analysé les liens qui existent entre mortalités par surdose de drogues illicites et inégalités socio-économiques d’usagers suivis durant dix-huit ans. Les pistes de réflexion mises en avant dans cet ouvrage permettent de mieux saisir comment les conséquences néfastes pour l’individu, sa famille et la collectivité peuvent être en partie évitées ou réduites grâce à la mise en place de stratégies adaptées de prévention, de programmes de promotion de la santé et d’interventions psycho-socioéducatives. Cet ouvrage fournit des éléments de réflexion aux décideurs politiques, aux intervenants spécialisés en toxicomanie, aux professionnels de santé et du social pour pouvoir mieux décider et agir. [less ▲]

Kollektiver Eigensinn oder Selbstbehinderung? Das umstrittene Körperwissen der Anorexie

in Keller, Reiner; Meuser, Michael (Eds.) Vergängliche Körper (2016)

Impact of HIV Perception on the on the Quality of Life of People Living with HIV - Mediation Effects of Flexible and Tenacious Goal Pursuit

in Psychology, Health and Medicine (2016), 22

Medical advances contribute to raise life expectancy of people living with HIV/AIDS (PLHIV). However, they still face challenges related to the disease, thus, quality of life (QOL) became a priority on ... [more ▼]

Medical advances contribute to raise life expectancy of people living with HIV/AIDS (PLHIV). However, they still face challenges related to the disease, thus, quality of life (QOL) became a priority on the field. The self-regulatory model (SRM) guided this study. Illness perceptions (IP) are the beliefs, cognitions, representations of a disease, impacting PLHIV coping strategies and QOL. Tenacious goal pursuit (TGP) is the pursuit of goals with determination, flexible goal adjustment (FGA) is doing it with flexibility, disengaging if necessary, they can both be considered as coping strategies. This study aims to measure the impact of HIV Perception in the QOL of PLHIV mediated by the TGP and FGA. Data was collected from 196 PLHIV with the WHOQOL-HIV Bref, the Brief-IPQ and the FGA and TGP scales. Structural equation model provided a good fit consistent with the theoretical SRM. IP, TGP and FGA had direct effects on the QOL of PLHIV. IP had also an indirect effect (partially mediated by TGP/FGA), suggesting that TGP/FGA reduce the impact of a threatening IP in the QOL. Goal oriented interventions should focus in the HIV perception of PLHIV to ameliorate their QOL [less ▲]

Special Issue on Aging and Migration in Europe

in GeroPsych: Journal of Gerontopsychology and Geriatric Psychiatry (2016), 29(2),

Europe is experiencing demographic and social challenges unprecedented in its history. Migration flows, though not a new phenomenon, represent one of these challenges. Migration as the movement of social ... [more ▼]

Europe is experiencing demographic and social challenges unprecedented in its history. Migration flows, though not a new phenomenon, represent one of these challenges. Migration as the movement of social and national groups within as well as into Europe includes several motivations and objectives. Depending on these motivations, migrants are considered as welcome asset or as not-wanted claiming benefits of the national social security systems. What can we learn from earlier migration waves? Currently, a large number of first-generation immigrants of the big immigration waves of the 1960s and 1970s are approaching retirement age in many European countries. Contrary to earlier expectations, studies have shown that only a part of these aging migrants return to their countries of origin after retirement, whereas a larger part decides to stay permanently in the receiving country or to commute between both countries. Growing old in the context of migration has thus become a hot topic for many societies. Based on research from several European countries with large shares of immigrants, namely UK, Estonia, Denmark and Luxembourg, the special issue aging and migration focuses on some key questions regarding aging migrants. For instance, what do we know about cultural and ethnic identities of older migrants and how these are related to their transnational family relationships? How can social networks and intergenerational family solidarity of older migrants be described? What are specifics of care in the context of acculturation? The present contributions give some first answers to these questions, taking also into account how subjective well-being of aging migrants and their families might be enhanced. [less ▲]

Collateral Damage of Facebook Apps: Friends, Providers, and Privacy Interdependence

in Symeonidis, Iraklis (Ed.) ICT Systems Security and Privacy Protection (2016)

Third-party apps enable a personalized experience on social networking platforms; however, they give rise to privacy interdependence issues. Apps installed by a user's friends can collect and potentially ... [more ▼]

Third-party apps enable a personalized experience on social networking platforms; however, they give rise to privacy interdependence issues. Apps installed by a user's friends can collect and potentially misuse her personal data inflicting collateral damage on the user while leaving her without proper means of control. In this paper, we present a multi-faceted study on the collateral information collection of apps in social networks. We conduct a user survey and show that Facebook users are concerned about this issue and the lack of mechanisms to control it. Based on real data, we compute the likelihood of collateral information collection affecting users; we show that the probability is significant and depends on both the friendship network and the popularity of the app. We also show its significance by computing the proportion of exposed user attributes including the case of profiling, when several apps are offered by the same provider. Finally, we propose a privacy dashboard concept enabling users to control the collateral damage. [less ▲]

Optical spectroscopy study on the photo-response in multiferroic BiFeO3

in Applied Physics Letters (2016), 109(18),

We investigate the underlying mechanism of the photostriction effect in single-crystalline BiFeO3 by transmission measurements in the infrared and visible frequency range under continuous illumination ... [more ▼]

We investigate the underlying mechanism of the photostriction effect in single-crystalline BiFeO3 by transmission measurements in the infrared and visible frequency range under continuous illumination with a green 532 nm). The small photo-induced changes in the transmission spectrum reveal three well-defined absorption features at 1.22 eV, 1.66 eV, and 2.14 eV, which we assign to charge-transfer excitons and in-gap defect states probably related to oxygen vacancies. The intensity of the three absorption features follows a linear dependence on the illumination intensity for an irradiance above 90 W/m(2). Published by AIP Publishing. [less ▲]

Is the Cu/Zn disorder the main culprit for the voltage deficit in kesterite solar cells?

in Advanced Energy Materials (2016), 6 - 15002276

Multiple strain-induced phase transitions in LaNiO3 thin films

in Physical Review. B (2016), 94(1),

Strain effects on epitaxial thin films of LaNiO3 grown on different single crystalline substrates are studied by Raman scattering and first-principles simulation. New Raman modes, not present in bulk or ... [more ▼]

Strain effects on epitaxial thin films of LaNiO3 grown on different single crystalline substrates are studied by Raman scattering and first-principles simulation. New Raman modes, not present in bulk or fully relaxed films, appear under both compressive and tensile strains indicating symmetry reductions. Interestingly, the Raman spectra and the underlying crystal symmetry for tensile and compressively strained films are different. Extensive mapping of LaNiO3 phase stability is addressed by simulations, showing that a variety of crystalline phases are indeed stabilized under strain. The calculated Raman frequencies reproduce the principal features of the experimental spectra, supporting the validity of the multiple strain-driven structural transitions predicted by the simulations. [less ▲]

Two Conserved Histone Demethylases Regulate Mitochondrial Stress-Induced Longevity.

in Cell (2016), 165(5), 1209-1223

Across eukaryotic species, mild mitochondrial stress can have beneficial effects on the lifespan of organisms. Mitochondrial dysfunction activates an unfolded protein response (UPR(mt)), a stress ... [more ▼]

Across eukaryotic species, mild mitochondrial stress can have beneficial effects on the lifespan of organisms. Mitochondrial dysfunction activates an unfolded protein response (UPR(mt)), a stress signaling mechanism designed to ensure mitochondrial homeostasis. Perturbation of mitochondria during larval development in C. elegans not only delays aging but also maintains UPR(mt) signaling, suggesting an epigenetic mechanism that modulates both longevity and mitochondrial proteostasis throughout life. We identify the conserved histone lysine demethylases jmjd-1.2/PHF8 and jmjd-3.1/JMJD3 as positive regulators of lifespan in response to mitochondrial dysfunction across species. Reduction of function of the demethylases potently suppresses longevity and UPR(mt) induction, while gain of function is sufficient to extend lifespan in a UPR(mt)-dependent manner. A systems genetics approach in the BXD mouse reference population further indicates conserved roles of the mammalian orthologs in longevity and UPR(mt) signaling. These findings illustrate an evolutionary conserved epigenetic mechanism that determines the rate of aging downstream of mitochondrial perturbations. [less ▲]