Acoustic mapping of benthic sediments

There is an increasing demand for knowledge of habitats, communities and distribution patterns of the seafloor for impact assessment, conservation and ecological studies. The European Union Water Framework directive will require a lot of effort to be met. In this study acoustic mapping of benthic communities and the factors that may influence the acoustic data has been examined, as well as the usage of sediment profile images (SPI). The survey area is located outside the town of Drøbak in the Oslofjord. An acoustic map of the area was made and four different acoustic classes were detected. Sampling of sediment and fauna from three of the four classes was made. SPI pictures were also taken from three of the classes. Sediment composition seemed to have no apparent affect on the acoustic data, the high concentration of organic carbon suggests that it might be the infauna that is the biggest contributor to the differences in the acoustic data. The faunal composition had a high similarity between the stations, but there was spread that followed the acoustic classes to some degree. Some of the shortcomings of the acoustic method have also been noted, and steps to compensate for this in the future are mentioned. The SPI pictures were in accordance with pictures made by others from the same area. Both SPI and acoustic mapping are cost effective methods for remote sensing of the seabed, but they will not replace traditional ground truthing, merely compensate and improve it

Bubbles in graphene - a computational study

Strain-induced deformations in graphene are predicted to give rise to large pseudomagnetic fields. We examine theoretically the case of gas-inflated bubbles to determine whether signatures of such fields are present in the local density of states. Sharp-edged bubbles are found to induce Friedel-type oscillations which can envelope pseudo-Landau level features in certain regions of the bubble. However, bubbles which minimise interference effects are also unsuitable for pseudo-Landau level formation due to more spatially varying field profiles.Comment: Submitted to Edison1

Patched Green's function techniques for two dimensional systems: Electronic behaviour of bubbles and perforations in graphene

We present a numerically efficient technique to evaluate the Green's function for extended two dimensional systems without relying on periodic boundary conditions. Different regions of interest, or `patches', are connected using self energy terms which encode the information of the extended parts of the system. The calculation scheme uses a combination of analytic expressions for the Green's function of infinite pristine systems and an adaptive recursive Green's function technique for the patches. The method allows for an efficient calculation of both local electronic and transport properties, as well as the inclusion of multiple probes in arbitrary geometries embedded in extended samples. We apply the Patched Green's function method to evaluate the local densities of states and transmission properties of graphene systems with two kinds of deviations from the pristine structure: bubbles and perforations with characteristic dimensions of the order of 10-25 nm, i.e. including hundreds of thousands of atoms. The strain field induced by a bubble is treated beyond an effective Dirac model, and we demonstrate the existence of both Friedel-type oscillations arising from the edges of the bubble, as well as pseudo-Landau levels related to the pseudomagnetic field induced by the nonuniform strain. Secondly, we compute the transport properties of a large perforation with atomic positions extracted from a TEM image, and show that current vortices may form near the zigzag segments of the perforation

Can magnetic resonance imaging differentiate undifferentiated arthritis?

A high sensitivity for the detection of inflammatory and destructive changes in inflammatory joint diseases makes magnetic resonance imaging potentially useful for assigning specific diagnoses, such as rheumatoid arthritis and psoriatic arthritis in arthritides, that remain undifferentiated after conventional clinical, biochemical and radiographic examinations. With recent data as the starting point, the present paper describes the current knowledge on magnetic resonance imaging in the differential diagnosis of undifferentiated arthritis

Dual-probe spectroscopic fingerprints of defects in graphene

Recent advances in experimental techniques emphasize the usefulness of multiple scanning probe techniques when analyzing nanoscale samples. Here, we analyze theoretically dual-probe setups with probe separations in the nanometer range, i.e., in a regime where quantum coherence effects can be observed at low temperatures. In a dual-probe setup the electrons are injected at one probe and collected at the other. The measured conductance reflects the local transport properties on the nanoscale, thereby yielding information complementary to that obtained with a standard one-probe setup (the local density-of-states). In this work we develop a real space Green's function method to compute the conductance. This requires an extension of the standard calculation schemes, which typically address a finite sample between the probes. In contrast, the developed method makes no assumption on the sample size (e.g., an extended graphene sheet). Applying this method, we study the transport anisotropies in pristine graphene sheets, and analyze the spectroscopic fingerprints arising from quantum interference around single-site defects, such as vacancies and adatoms. Furthermore, we demonstrate that the dual-probe setup is a useful tool for characterizing the electronic transport properties of extended defects or designed nanostructures. In particular, we show that nanoscale perforations, or antidots, in a graphene sheet display Fano-type resonances with a strong dependence on the edge geometry of the perforation

General Practitioners' Barriers Toward Medication Reviews in Polymedicated Multimorbid Patients:How can a Focus on the Pharmacotherapy in an Outpatient Clinic Support GPs?

Purpose: The aim of this study was to explore whether general practitioners (GPs) experienced barriers toward medication reviews in polymedicated, multimorbid patients, and how a clinical pharmacologist with a focus on pharmacotherapy can support the GPs in an outpatient clinic. Design: The study was descriptive and exploratory and had a qualitative design with a phenomenological/hermeneutic orientation for the interviews. Participants: The study comprised 14 interviews with 14 different GPs from the Capital Region of Denmark. Results: Three themes emerged from the interviews: (1) The care of patients With polypharmacy is challenged by the lack of professional dialogue and collaboration between GPs and hospital-based clinical pharmacologists, (2) the relationship between the patients with polypharmacy and the GP is characterized by care and individual considerations, and (3) the culture encourages adding medication and inhibits dialogue about medication withdrawal even for patients with polypharmacy. Conclusion and implications for practice: This study found that the primary barriers toward multimorbid patients with polypharmacy were the need for communication and teamwork with specialists (cardiologists, neurologists, endocrinologists, etc). Often, GPs felt that the specialists at the hospitals were more concerned about following standards and guidelines regarding specific diseases instead of a more holistic patient approach. To improve management of polypharmacy patients, the GPs suggest that a joint force is necessary, a partner-like relationship with greater transparency regarding information transfer, feedback, and shared decision-making, but also more education in the pharmacological field is essential