Geometric spin Hall effect of light in tightly focused polarization tailored light beams

Recently, it was shown that a non-zero transverse angular momentum manifests itself in a polarization dependent intensity shift of the barycenter of a paraxial light beam [A. Aiello et al., Phys. Rev. Lett. 103, 100401 (2009)]. The underlying effect is phenomenologically similar to the spin Hall effect of light, but does not depend on the specific light-matter interaction and can be interpreted as a purely geometric effect. Thus, it was named the geometric spin Hall effect of light. Here, we experimentally investigate the appearance of this effect in tightly focused vector-beams. We use an experimental nano-probing technique in combination with a reconstruction algorithm to verify the relative shifts of the components of the electric energy density in the focal plane, which are linked to the intensity shift. By that, we experimentally demonstrate the geometric spin Hall effect of light in a focused light beam.Comment: 8 pages, 5 figure

Die Beteiligung von Frauen in der Politik im ländlichen Raum : Ländliche Regionalentwicklung und politische Partizipation

Im Diskurs der ländlichen Regionalentwicklung wird als ein wichtiger Ansatzpunkt für eine nachhaltige Entwicklung ländlicher Räume das Engagement der Menschen vor Ort gesehen. Über deren Aktivierung und Einbindung in Regionalentwicklungsprozesse wird dabei versucht eine gemeinsame Strategie aller für die Zukunft zu entwickeln. Hier ist die Verschränkung zwischen dem politischen und zivilgesellschaftlichen Diskurs besonders wichtig, wenn ein solcher Prozess erfolgreich sein soll. Der nachfolgende Artikel greift den Aspekt des politischen Engagements von Frauen in ländlichen Räumen heraus und analysiert Beteiligungsmöglichkeiten und – motive aus der Genderperspektive

Knowledge and Perceptions of Electronic Cigarette Use among Pregnant Women

poster abstractThe association between maternal tobacco smoke exposure and restricted fetal growth has been well studied. However, the safety of electronic cigarettes (e-cigarettes) is quite controversial among pregnant women and the public. Research on the health effects of e-cigarette use during pregnancy is limited, particularly because of the health risks and ethical considerations. However, there is concern about the effects of the nicotine on fetal health from e-cigarettes. Some women’s beliefs about e-cigarettes are influenced by information that e-cigarettes may be beneficial as a way to decrease the number of tobacco cigarettes smoked. We conducted a systematic review of the literature to explore the knowledge and perceptions of e-cigarette use among pregnant women. Using pre-designated inclusion and exclusion criteria, relevant articles were located and reviewed searching PubMed, EMBASE, EBSCOhost, CINAHL Complete, and the reference lists of related articles. Full text, English language, peer-reviewed articles relevant to pregnant women’s knowledge and perceptions of e-cigarettes were reviewed. Of the thirty studies, six met the inclusion criteria. The following findings were common among the studies reviewed: 1) study participants had inaccurate information regarding the amount of nicotine in ecigarettes and the effects on the fetus; 2) e-cigarettes were perceived as safe alternatives and could be used for smoking cessation; 3) using e-cigarettes caused less negative side effects than traditional cigarettes; and 4) information obtained from the media about e-cigarettes was confusing for pregnant women. The findings support the need for healthcare providers to assess e-cigarette use among pregnant women and provide accurate information regarding e-cigarettes and the potential impact of use during pregnancy

Dauer der Infektionsfähigkeit von Steinbrand (Tilletia caries)- und Zwergsteinbrandsporen (Tilletia controversa) im Boden und Stallmist unter Berücksichtigung verschiedener Fruchtfolgen in Biobetrieben

Mit Hilfe neuer Untersuchungsmethoden ist es in einem Forschungsprojekt erstmals gelungen, das Brandsporenpotential von Steinbrand (Tilletia caries)- und Zwergsteinbrand (Tilletia controversa) im Boden quantitativ zu erfassen und zu bestimmen (Dressler et al. 2011). Bei Zwergsteinbrand ist seit langem bekannt, dass neue Infektionen vom Boden aus erfolgen. Bei Steinbrand konnte dies erstmals nachgewiesen werden. Mit Feldversuchen auf Öko-Flächen, die ein hohes Sporenpotential aufweisen, soll anhand verschiedener Fruchtfolgen untersucht werden, ob unterschiedliche Bewirtschaftungen die Infektionsfähigkeit der Sporen beeinflussen. Es werden zum einen sehr gegensätzliche Bewirtschaftungen, wie offengehaltene Brache- und ständig bewachsene Kleegrasflächen durchgeführt. Zum anderen kommen praxisübliche Getreidearten und Futtererbsen zum Anbau. Mit Senf als Zwischenfrucht wird untersucht, ob Senföle einen Einfluss auf die Infektionsfähigkeit der Brandsporen haben. Zusätzlich wird festgestellt, wie sich die Sporenanzahl in befallenem Stallmist im Zeitverlauf unter Berücksichtigung der Abbauprozesse verändert

The photonic wheel: demonstration of a state of light with purely transverse angular momentum

The concept of angular momentum is ubiquitous to many areas of physics. In classical mechanics, a system may possess an angular momentum which can be either transverse (e.g., in a spinning wheel) or longitudinal (e.g., for a fluidic vortex) to the direction of motion. Photons, however, are well-known to exhibit intrinsic angular momentum which is longitudinal only: the spin angular momentum defining the beam polarization and the orbital angular momentum associated with a spiraling phase front. Here we show that it is possible to generate a novel state of light that contains purely transverse angular momentum, the analogue of a spinning mechanical wheel. We use an optical nano-probing technique to experimentally demonstrate its occurrence in our setup. Such a state of light can provide additional rotational degree of freedom in optical tweezers and optical manipulation.Comment: 15 pages including SO

Science-Policy Interactions in a Corporatist System: Knowledge Brokerage in Austrian Climate Policy

Climate change policy is a prime example for the growing importance of expert ad-vice to inform decision‐making. Consequently, a plethora of advisory bodies and pro-cesses have emerged around the world. However, there are marked differences in the way the interactions between science and politics are organized and practiced depending on a country’s political system and culture. The degree of political compe-tition, the role of state vis-à-vis non-state actors and the dominant modes of interest mediation provide specific conditions for the ways expertise is consulted and used in decision-making. Against this background, the paper presents the landscape of scientific advice in Austrian climate policy and asks in how far the traditionally strong culture of corporat-ism in Austrian politics manifests itself in practices of climate policy advice. Concep-tually, the paper draws on analytical dimensions derived from the concepts of “na-tional styles of policy-making” and “civic epistemology”. Methodically it bases on an interview series and a workshop with representatives from science, politics, and in-termediary organizations. Our analysis provides a differentiated picture: the neo-corporatist culture still leaves its imprint in Austrian climate policy advice. But at the same time, the emergence of a new policy field, such as climate policy, undoubtedly opens up possibilities for new actors and forms of policy advice

Greener households? The effectiveness of smart meters in reducing energy consumption levels in the DACH region

With public opinion shifting to a believe in climate change in the early 2000s the interest in energy efficiency has been increasing. EU Directives set the goal of deploying smart meters if cost efficient for providing more detailed energy consumption. The main goal is to better inform consumers and to give individual households the power to change possibly energy wasting behaviours. This paper evaluates through a literature review the effectiveness of intelligent electricity metering systems with a focus on the DACH region, the provision of different types of feedback and its persistence. It can be concluded that energy feedback enabled by smart meters can lead to savings in the range of 0% to 4.5% in this region. If feedback is provided continuously savings persist. However, several aspects have to be considered to ensure effectiveness of smart meter deployment