Miniature photonic-crystal hydrophone optimized for ocean acoustics

This work reports on an optical hydrophone that is insensitive to hydrostatic pressure, yet capable of measuring acoustic pressures as low as the background noise in the ocean in a frequency range of 1 Hz to 100 kHz. The miniature hydrophone consists of a Fabry-Perot interferometer made of a photonic-crystal reflector interrogated with a single-mode fiber, and is compatible with existing fiber-optic technologies. Three sensors with different acoustic power ranges placed within a sub-wavelength sized hydrophone head allow a high dynamic range in the excess of 160 dB with a low harmonic distortion of better than -30 dB. A method for suppressing cross coupling between sensors in the same hydrophone head is also proposed. A prototype was fabricated, assembled, and tested. The sensitivity was measured from 100 Hz to 100 kHz, demonstrating a minimum detectable pressure down to 12 {\mu}Pa (1-Hz noise bandwidth), a flatband wider than 10 kHz, and very low distortion

Telephone follow-up by nurse following total knee arthroplasty - protocol for a randomized clinical trial (NCT01771315)

BACKGROUND: Due to shorter hospitalization, patients have to take responsibility for their rehabilitation period at a very early stage. The objective of this trial is to study the effects of two treatment schemes following total knee arthroplasty: conventional treatment following discharge from hospital and early follow-up by telephone consultations in addition to conventional treatment following discharge from hospital. The ultimate aim is to increase the effectiveness of the treatment by improving patients' health status, promote self-efficacy, and reduce the number of acute visits to the orthopaedic outpatient clinic during the rehabilitation period. METHOD/DESIGN: The design is a randomized un-blinded parallel group clinical trial conducted at the Department of Orthopaedic Surgery, Gentofte Hospital, the Capital Region of Denmark. In total, 116 patients will be allocated by an external randomization program to 2 groups: an intervention group following usual treatment after discharge supplemented by a nurse managed structured follow-up consultation conducted by telephone 4 and 14 days after discharge from hospital and a control group following treatment as usual. The consultations are structured by key subjects relevant to assess the health status according to the VIPS-model (the Swedish acronym for the concepts Well-being, Integrity, Prevention and Safety). The content of the consultations can vary according to the patients´ individual situations and needs. All consultations are conducted by the researcher responsible for the trial. The effect is measured 1, 3, 6 and 12 months post-surgery. The primary outcome is self-reported physical function measured by The Western Ontario and McMaster Universities Arthritis Index. Secondary outcomes are self-reported health-related quality of life, general self-efficacy and the number of acute visits to the orthopaedic outpatient clinic. DISCUSSION: The result of this trial is expected to provide new knowledge to support the development of targeted and effective follow-up after total knee arthroplasty in order to improve the patients´ health-related knowledge and skills of being able to take actively part in their illness and improve their health status. TRIAL REGISTRATION: ClinicalTrials.gov: NCT0177131

The Europeanisation of Everyday Life: Cross-Border Practices and Transnational Identifications Among EU and Third-Country Citizens State of the Art Report

This paper illustrates the research questions, the main underlying concepts and the relevant literature of the EUCROSS project. It reports on the existing literature in sociology, anthropology, political sciences and social psychology related to the project which seeks to examine the relationship between the manifold activities of EU residents (nationals, mobile EU citizens, and third country nationals) across the borders of nation states and their collective identities. It raises questions about 1) how to map out individuals’ cross-border practices as an effect of European integration and globalisation; and 2) assess the impact of these practices on collective identifications, while also controlling for the inverse causal process. Which cross-border practices are more likely to foster some form of identification with the EU – e.g., contacts with foreign friends and/or unwanted foreigners, periods of labour mobility abroad, business and tourist travel, or consumer relations with international companies? Under which contextual and individual conditions do these experiences promote a higher sensitivity to ‘Europe’ – rather than the ‘local’ or the ‘global’ – as an identity catalyst? Which social groups are more likely to adopt a European mindset in the wake of the Europeanisation of everyday life? While substantial separate literatures about ‘Europeanisation’, ‘European identity’, ‘cross-border practices’ and ‘cosmopolitanism’ can be found, we argue that seldom are these concepts treated altogether to specify the link between spatially and culturally situated behaviours on the one hand and collective identifications and value orientations on the other. Moreover, few studies examine socio-cultural Europeanisation and supernational identifications comparatively, and none include simultaneously native and immigrant populations, who in fact may attest of different modalities in which the behaviour-identity link can take place

Resonant harmonic response in tapping-mode atomic force microscopy

Cataloged from PDF version of article.Higher harmonics in tapping-mode atomic force microscopy offers the potential for imaging and sensing material properties at the nanoscale. The signal level at a given harmonic of the fundamental mode can be enhanced if the cantilever is designed in such a way that the frequency of one of the higher harmonics of the fundamental mode ~designated as the resonant harmonic! matches the resonant frequency of a higher-order flexural mode. Here we present an analytical approach that relates the amplitude and phase of the cantilever vibration at the frequency of the resonant harmonic to the elastic modulus of the sample. The resonant harmonic response is optimized for different samples with a proper design of the cantilever. It is found that resonant harmonics are sensitive to the stiffness of the material under investigation