Volunteer Work, Informal Help, and Care among the 50+ in Europe: Further Evidence for 'Linked' Productive Activities at Older Ages

Objectives - Taking a cross-national comparative perspective, we investigate linkages between volunteer work, informal helping, and caring among Europeans aged 50 or older: Is the relationship between these activities characterized by complementarity or by substitution? Is there evidence for the existence of (unobserved) personality traits that foster engagement independent of a specific activity? Methods - Based on 27,305 personal interviews from the 2004 Survey of Health, Ageing and Retirement in Europe (SHARE), we estimate univariate and multivariate probit models, which allow us to analyze the interrelationship between different productive activities and the derterminants of individuals' engagement therein. Results - There is substantial variation in the participation in volunteering, helping, and caring between countries and regions. Independent of the general level of activity in a country, we find evidence for a complementary and interdependent relationship between all three activities. Discussion - Our findings not only suggest an important role of societal opportunity structures in elders' productive engagement, but they also support recent notions of the existence of a general motivation for engagement in productive activities, independent of a specific domain of activity. Thus, the study of motivations should be an important aspect of future research on productive aging.

Volunteer Work, Informal Help, and Care among the 50+ in Europe: Further Evidence for ‘Linked’ Productive Activities at Older Ages

Taking a cross-national perspective, we investigate linkages between volunteer work, informal help, and care among Europeans aged 50 or older. Based on 27,305 personal interviews from the 2004 Survey of Health, Ageing and Retirement in Europe, we estimate univariate and multivariate probit models, which allow us to analyze the interrelationship between different productive activities. There is substantial variation in the participation in volunteering, helping, and caring between countries and regions. Independent of the general level of activity in a country, we find evidence for a complementary and interdependent relationship between all three activities. Our findings not only suggest an important role of societal opportunity structures in elders' productive engagement, but also support notions of the existence of a general motivation for engagement in productive activities.

Informelle Arbeit älterer Frauen und Männer in Europa

Zwei Themen finden sich in den letzten Jahren verstärkt in der gesellschaftlichen Diskussion wieder: zum einen der demographische Wandel und die so genannte ‚Überalterung’ europäischer Gesellschaften, zum anderen ehrenamtliches Engagement und hier insbesondere der Beitrag, den ältere BürgerInnen leisten können. Nicht zuletzt begünstigt durch anhaltende Reformdiskussionen werden ältere Menschen oftmals als Belastung für die Gesellschaft dargestellt, da sie aufgrund von Rentenansprüchen und Pflegebedürftigkeit viel Geld kosten. Durch die gestiegene Lebenserwartung und die gute Gesundheitslage vieler Älterer ergibt sich hingegen ein Potential an aktiven BürgerInnen, die sich für andere Menschen und die Gesellschaft engagieren und somit informelle Arbeit leisten.

A balanced gated-mode photon detector for qubit discrimination in 1550 nm

A photon detector combining the two avalanche photon diodes (APD) has been demonstrated for qubit discrimination in 1550 nm. Spikes accompanied with the signals in gated-mode were canceled by balanced output from the two APDs. The spike cancellation enabled one to reduce the threshold in the discriminators, and thus the gate pulse voltage. The dark count probability and afterpulse probability were reduced to 7x10^-7 and 10^-4, respectively, without affecting the detection efficiency (11 %) at 178 K.Comment: 6 pages, 5 figures, submitted to Optics Letters on March 1

Ehrenamt, Netzwerkhilfe und Pflege in Europa – Komplementäre oder konkurrierende Dimensionen produktiven Alterns?

Vor dem Hintergrund der öffentlichen und wissenschaftlichen Debatte um die Bedeutung produktiven Alterns jenseits der Erwerbsarbeit (z.B. Avramov & Maskova 2003; Morrow-Howell et al. 2001) schließt der vorliegende Beitrag an eine Reihe neuerer, international vergleichend angelegter Studien an, die verschiedene Dimensionen informeller produktiver Tätigkeiten untersuchen, ohne dabei allerdings durchweg auf die hier vor allem interessierende ältere Bevölkerung zu fokussieren. Im Bereich des Ehrenamtes sind in diesem Zusammenhang vor allem die Arbeiten von Curtis et al. (2001), Schofer & Fourcade-Gourinchas (2001) sowie Salamon & Sokolowski (2003) zu nennen. Entsprechende Analysen von Pflegetätigkeiten wurden u.a. von Alber & Köhler (2004) sowie – im Rahmen des OASIS-Projektes – von Daatland & Lowenstein (2005) und Motel-Klingebiel et al. (2005) untersucht. Auch auf Basis einer früheren Version – Release 1 – der diesem Beitrag zu Grunde liegenden Daten des ‚Survey of Health, Ageing and Retirement in Europe’ (SHARE) liegen bereits Studien zum Ehrenamt und zur haushaltsexternen Unterstützung vor (vgl. Attias-Donfut et al. 2005; Erlinghagen & Hank 2006; Stuck 2007).1 Alle genannten Studien weisen auf teilweise erhebliche Länderunterschiede im Ausmaß informeller produktiver Tätigkeiten – unter Älteren wie in der Bevölkerung insgesamt – hin (vgl. auch Brugiavini et al. [2005] für einen Überblick zur Erwerbsbeteiligung Älterer im europäischen Vergleich). Unsere Untersuchung ergänzt die existierende Literatur und geht über diese hinaus, in dem sie auf der Grundlage strikt vergleichbarer Mikrodaten für 11 europäische Länder drei Dimensionen informeller Arbeit – Ehrenamt, Netzwerkhilfe und Pflege – gemeinsam betrachtet und deren Determinanten multivariat analysiert. Ein zentrales Anliegen der Untersuchung ist es, neben einem deskriptiven Vergleich auf Länderebene, zu einem besseren Verständnis des Verhältnisses der genannten Tätigkeiten zueinander beizutragen: handelt es sich bei Ehrenamt, Netzwerkhilfe und Pflege um komplementäre oder um konkurrierende Dimensionen produktiven Alterns in Europa und gibt es Hinweise auf (unbeobachtete) Persönlichkeitsmerkmale, die unabhängig von spezifischen Tätigkeitsformen Aktivität im Alter insgesamt fördern? Der Beitrag gibt zunächst einen kurzen Überblick über die neuere Literatur zum Zusammenhang zwischen verschiedenen Formen (informeller) produktiver Tätigkeiten.2 Anschließend stellen wir kurz unsere Datenbasis vor und beschreiben die in der Analyse verwendeten Variablen. Danach präsentieren wir zentrale deskriptive Befunde zur Beteiligung älterer Europäer an informeller Arbeit und stellen die Ergebnisse der multivariaten Analyse vor. Der Beitrag schließt mit einem Ausblick auf zukünftige Forschungsperspektiven.

Apical Sarcomere-like Actomyosin Contracts Nonmuscle Drosophila Epithelial Cells

Actomyosin networks generate contractile force that changes cell and tissue shape. In muscle cells, actin filaments and myosin II appear in a polarized structure called a sarcomere, in which myosin II is localized in the center. Nonmuscle cortical actomyosin networks are thought to contract when nonmuscle myosin II (myosin) is activated throughout a mixed-polarity actin network. Here, we identified a mutant version of the myosin-activating kinase, ROCK, that localizes diffusely, rather than centrally, in epithelial cell apices. Surprisingly, this mutant inhibits constriction, suggesting that centrally localized apical ROCK/myosin activity promotes contraction. We determined actin cytoskeletal polarity by developing a barbed end incorporation assay for Drosophila embryos, which revealed barbed end enrichment at junctions. Our results demonstrate that epithelial cells contract with a spatially organized apical actomyosin cortex, involving a polarized actin cytoskeleton and centrally positioned myosin, with cell-scale order that resembles a muscle sarcomere.National Institutes of Health (U.S.) (GM06806)American Heart Association (Grant-in-aid 14GRNT1888005)American Cancer Society (grant 125792-RSG-14-039-01-CS)National Institutes of Health (U.S.) (Pre-Doctoral Training Grant T32GM00728

ENSO impact on simulated South American hydro-climatology

The variability of the simulated hydro-climatology of the WaterGAP Global Hydrology Model (WGHM) is analysed. Main object of this study is the ENSO-driven variability of the water storage of South America. The horizontal model resolution amounts to 0.5 degree and it is forced with monthly climate variables for 1961-1995 of the Tyndall Centre Climate Research Unit dataset (CRU TS 2.0) as a representation of the observed climate state. Secondly, the model is also forced by the model output of a global circulation model, the ECHAM4-T42 GCM. This model itself is driven by observed monthly means of the global Sea Surface Temperatures (SST) and the sea ice coverage for the period of 1903 to 1994 (GISST). Thus, the climate model and the hydrological model represent a realistic simulated realisation of the hydro-climatologic state of the last century. Since four simulations of the ECHAM4 model with the same forcing, but with different initial conditions are carried out, an analysis of variance (ANOVA) gives an impression of the impact of the varying SST on the hydro-climatology, because the variance can be separated into a SST-explained and a model internal variability (noise). Also regional multivariate analyses, like Empirical Orthogonal Functions (EOF) and Canonical Correlation Analysis (CCA) provide information of the complex time-space variability. In particular the Amazon region and the South of Brazil are significantly influenced by the ENSO-variability, but also the Pacific coastal areas of Ecuador and Peru are affected. Additionally, different ENSO-indices, based on SST anomalies (e.g. NINO3.4, NINO1+2), and its influence on the South American hydro-climatology are analysed. Especially, the Pacific coast regions of Ecuador, Peru and Chile show a very different behaviour dependant on those indices

Network Structures in Regional Innovation Systems

While interactive learning and inter-organisational relations are fundamental building blocks in RIS theory, the framework is rarely related to investigations of regional knowledge network structures, because in RIS literature relational structures and interaction networks are discussed in a rather fuzzy and generic manner with the ‘network term’ often being used rather metaphorically. This paper contributes to the literature by discussing theoretical arguments about interactions and knowledge exchange relations in the RIS literature from the perspective of social network analysis. More precise, it links network theoretical concepts and insights to the well-known classification of RIS types by Cooke (2004). We thereby exemplarily show how the RIS literature and the literature on regional knowledge networks can benefit from considering insights of the respective other

Compensation in undoped and halogen doped CdTe crystals

A theoretical model is proposed which allows the calculation of the concentration of defects in pure and halogen compensated cadmium telluride grown by the THM method. All associations and ionization reactions are described in terms of the law of mass action. The ionization energies of the defects are taken from the energy level diagram established by taking into account the latest experimental data. The concentrations of the different defects calculated for chlorine doped material are in good agreement with that measured using a time of flight method

Recuit laser de cellules solaires fonctionnant sous concentration

La résistance série élevée des cellules conventionnelles au silicium rend leur fonctionnement difficile sous concentration. Nous montrons ici que l'irradiation de la couche superficielle diffusée par un faisceau laser pulsé de grande intensité permet de réduire notamment la résistance série, de sorte que des rendements de conversion de 15 % sous 30 soleils et de 12,5 % sous 100 soleils (10 W/cm2) sont prévus par le calcul