No abstract

[1] Nonpropagating mirror-mode structures are commonly observed in many regions of natural plasma such as solar wind, planetary magnetosheaths, in cometary plasma, Io wake, terrestrial ring current and even on the outskirts of solar system. Mirror structures are typically observed in the shape of magnetic holes or peaks. Fast survey mode plasma data from the THEMIS satellites are used to solve the puzzle of how mirror structures in the form of dips can be observed in the regions of mirror stable plasma. THEMIS data also show that for mirror structures with spatial scales that considerably exceed ion Larmor radius the perpendicular temperature anticorrelates with the strength of the magnetic field. This contradiction with the conservation of adiabatic invariants is explained by the role of trapped particles.

ObjectiveTo assess the effect of coding quality on estimates of the incidence of diabetes in the UK between 1995 and 2014.DesignA cross-sectional analysis examining diabetes coding from 1995 to 2014 and how the choice of codes (diagnosis codes vs codes which suggest diagnosis) and quality of coding affect estimated incidence.SettingRoutine primary care data from 684 practices contributing to the UK Clinical Practice Research Datalink (data contributed from Vision (INPS) practices).Main outcome measureIncidence rates of diabetes and how they are affected by (1) GP coding and (2) excluding ‘poor’ quality practices with at least 10% incident patients inaccurately coded between 2004 and 2014.ResultsIncidence rates and accuracy of coding varied widely between practices and the trends differed according to selected category of code. If diagnosis codes were used, the incidence of type 2 increased sharply until 2004 (when the UK Quality Outcomes Framework was introduced), and then flattened off, until 2009, after which they decreased. If non-diagnosis codes were included, the numbers continued to increase until 2012. Although coding quality improved over time, 15% of the 666 practices that contributed data between 2004 and 2014 were labelled ‘poor’ quality. When these practices were dropped from the analyses, the downward trend in the incidence of type 2 after 2009 became less marked and incidence rates were higher.ConclusionsIn contrast to some previous reports, diabetes incidence (based on diagnostic codes) appears not to have increased since 2004 in the UK. Choice of codes can make a significant difference to incidence estimates, as can quality of recording. Codes and data quality should be checked when assessing incidence rates using GP data.

ObjectiveUK primary care databases, which contain diagnostic, demographic and prescribing information for millions of patients geographically representative of the UK, represent a significant resource for health services and clinical research. They can be used to identify patients with a specified disease or condition (phenotyping) and to investigate patterns of diagnosis and symptoms. Currently, extracting such information manually is time-consuming and requires considerable expertise. In order to exploit more fully the potential of these large and complex databases, our interdisciplinary team developed generic methods allowing access to different types of user.Materials and methodsUsing the Clinical Practice Research Datalink database, we have developed an online user-focused system (TrialViz), which enables users interactively to select suitable medical general practices based on two criteria: suitability of the patient base for the intended study (phenotyping) and measures of data quality.ResultsAn end-to-end system, underpinned by an innovative search algorithm, allows the user to extract information in near real-time via an intuitive query interface and to explore this information using interactive visualization tools. A usability evaluation of this system produced positive results.DiscussionWe present the challenges and results in the development of TrialViz and our plans for its extension for wider applications of clinical research.ConclusionsOur fast search algorithms and simple query algorithms represent a significant advance for users of clinical research databases.

[1] Mirror waves have been observed in many different plasma regions within solar system. In contrast to many other plasma waves, mirror mode waves are rarely observed as a quasi-periodic sinusoidal signature. Mirror structures in the form of magnetic dips are usually observed when the criterion for mirror instability is not satisfied in the plasma surrounding these structures. In contrast, magnetic peaks are observed in mirror unstable plasma. This paper reports on a study of the peak-type mirror structures in the terrestrial magnetosheath conducted using THEMIS magnetic field and plasma measurements. It is shown that the changes observed in the plasma temperature are inconsistent with the previously shared view that magnetic peaks are nonlinear mirror waves immersed in a background plasma. A model in which the non-linear mirror waves are composed of a series of peaks and troughs can help to explain the apparent contradictions between theory and observations.