Characteristics and Evolution of the Magnetic field and Chromospheric Emission in an Active Region Core Observed by Hinode

We describe the characteristics and evolution of the magnetic field and chromospheric emission in an active region core observed by the Solar Optical Telescope on Hinode. Consistent with previous studies, we find that the moss is unipolar, the spatial distribution of magnetic flux evolves slowly, and the magnetic field is only moderately inclined. We show that the field line inclination and horizontal component are coherent, and that the magnetic field is mostly sheared in the inter-moss regions where the highest magnetic flux variability is seen. Using extrapolations from SP magnetograms we show that the magnetic connectivity in the moss is different than in the quiet Sun because most of the magnetic field extends to significant coronal heights. The magnetic flux, field vector, and chromospheric emission in the moss also appear highly dynamic, but actually show only small scale variations in magnitude on time-scales longer than the cooling times for hydrodynamic loops computed from our extrapolations, suggesting high-frequency (continuous) heating events. Some evidence is found for flux (Ca 2 intensity) changes on the order of 100--200 G (DN) on time-scales of 20--30 mins that could be taken as indicative of low-frequency heating. We find, however, that only a small fraction (10%) of our simulated loops would be expected to cool on these time-scales, and we find no clear evidence that the flux changes consistently produce intensity changes in the chromosphere. The magnetic flux and chromospheric intensity in most individual SOT pixels in the moss vary by less than ~ 20% and ~ 10%, respectively, on loop cooling time-scales. In view of the high energy requirements of the chromosphere, we suggest that these variations could be sufficient for the heating of `warm' EUV loops, but that the high basal levels may be more important for powering the hot core loops rooted in the moss.Comment: Accepted by ApJ, 16 pages, 20 figures. Abridged abstract (original is in PDF file). Figures 1 & 2 are reduced resolution to meet size limit

Patient and Physician Perceptions of Dimensions of Necessity of Medical Utilization

The goal of this research was to understand better the perspectives held by physicians and patients regarding what factors determine the appropriateness of medical visits. We also wished to create a convenient measure of those perspectives. In our first study, we conducted focus groups separately composed of 22 physicians and 16 patients to determine their respective views. In our second study, a 40-item measure derived from Study 1 themes was administered to a sample of 202 patients. Study 1 identified 20 themes, collapsing into 6 dimensions. Physicians held views that some patients were manipulative when seeking medical care. Study 2 revealed factors of Symptom Experience and Doctor Expertise. The two studies revealed that the perception of medical utilization varies between patients and physicians, but both groups share many similar beliefs

EUV spectral line formation and the temperature structure of active region fan loops: observations with Hinode/EIS and SDO/AIA

With the aim of studying AR fan loops using Hinode/EIS and SDO/AIA, we investigate a number of inconsistencies in modeling the absolute intensities of Fe VIII and Si VII lines, and address why their images look very similar despite the fact that they have significantly different formation temperatures in ionization equilibrium: log T/K = 5.6 and 5.8. These issues are important to resolve because confidence has been undermined in their use for DEM analysis, and Fe VIII is the main contributor to the AIA 131A channel at low temperatures. Furthermore, they are the best EIS lines to use for velocity studies, and for assigning the correct temperature to velocity measurements in the fans. We find that the Fe VIII 185.213A line is particularly sensitive to the slope of the DEM, leading to disproportionate changes in its effective formation temperature. If the DEM has a steep gradient in the log T/K = 5.6 to 5.8 range, or is strongly peaked, Fe VIII 185.213A and Si VII 275.368A will be formed at the same temperature. We show that this effect explains the similarity of these images in the fans. Furthermore, we show that the most recent ionization balance compilations resolve the discrepancies in absolute intensities. We then combine EIS and AIA to determine the temperature structure of a number of fan loops and find that they have peak temperatures of 0.8--1.2MK. The EIS data indicate that the temperature distribution has a finite (but narrow) width < log sigma/K = 5.5 which, in one case, is found to broaden substantially towards the loop base. AIA and EIS yield similar results on the temperature, emission measure, and thermal distribution in the fans, though sometimes the AIA data suggest a relatively larger thermal width. The result is that both the Fe VIII 185.213A and Si VII 275.368A lines are formed at log T/K ~ 5.9 in the fans, and the AIA 131A response also shifts to this temperature.Comment: To be published in ApJ. Figure 6 is reduced resolution to meet size limits. The abstract has been significantly shortened (original in PDF file

The Temperature Dependence of Solar Active Region Outflows

Spectroscopic observations with the EUV Imaging Spectrometer (EIS) on Hinode have revealed large areas of high speed outflows at the periphery of many solar active regions. These outflows are of interest because they may connect to the heliosphere and contribute to the solar wind. In this Letter we use slit rasters from EIS in combination with narrow band slot imaging to study the temperature dependence of an active region outflow and show that it is more complicated than previously thought. Outflows are observed primarily in emission lines from Fe XI - Fe XV. Observations at lower temperatures (Si VII), in contrast, show bright fan-like structures that are dominated by downflows. The morphology of the outflows is also different than that of the fans. This suggests that the fan loops, which often show apparent outflows in imaging data, are contained on closed field lines and are not directly related to the active region outflows.Comment: Movies are available online at: http://tcrb.nrl.navy.mil/~hwarren/temp/papers/flow_temperatures/ To be submitted to ApJ

Book reviews

Teaching/Communication/Extension/Profession,

On active region loops: Hinode/EIS observations

Coronal loops are fundamental building blocks of the solar active regions and the corona. Therefore, a clear understanding of the physics of coronal loops will help us understand the physics of active region heating in particular and coronal heating in general. This requires a precise measurement of physical quantities such as electron densities and filling factors, temperatures, and flows in coronal loops. In this paper we have carried out an investigation of a spatially well resolved coronal loop using the EIS onboard Hinode to measure the above mentioned physical quantities. Based on this study we find that a nano-flare model could explain most of the observed characteristics of this loop.Comment: 27 pages, 7 figures, Accepted in Ap

Treatment of infections caused by multidrug-resistant Gram-negative bacteria:Report of the British Society for Antimicrobial Chemotherapy/Healthcare Infection Society/British Infection Association Joint Working Party

The Working Party makes more than 100 tabulated recommendations in antimicrobial prescribing for the treatment of infections caused by multidrug-resistant (MDR) Gram-negative bacteria (GNB) and suggest further research, and algorithms for hospital and community antimicrobial usage in urinary infection. The international definition of MDR is complex, unsatisfactory and hinders the setting and monitoring of improvement programmes. We give a new definition of multiresistance. The background information on the mechanisms, global spread and UK prevalence of antibiotic prescribing and resistance has been systematically reviewed. The treatment options available in hospitals using intravenous antibiotics and in primary care using oral agents have been reviewed, ending with a consideration of antibiotic stewardship and recommendations. The guidance has been derived from current peer-reviewed publications and expert opinion with open consultation. Methods for systematic review were NICE compliant and in accordance with the SIGN 50 Handbook; critical appraisal was applied using AGREE II. Published guidelines were used as part of the evidence base and to support expert consensus. The guidance includes recommendations for stakeholders (including prescribers) and antibiotic-specific recommendations. The clinical efficacy of different agents is critically reviewed. We found there are very few good-quality comparative randomized clinical trials to support treatment regimens, particularly for licensed older agents. Susceptibility testing of MDR GNB causing infection to guide treatment needs critical enhancements. Meropenem- or imipenem-resistant Enterobacteriaceae should have their carbapenem MICs tested urgently, and any carbapenemase class should be identified: mandatory reporting of these isolates from all anatomical sites and specimens would improve risk assessments. Broth microdilution methods should be adopted for colistin susceptibility testing. Antimicrobial stewardship programmes should be instituted in all care settings, based on resistance rates and audit of compliance with guidelines, but should be augmented by improved surveillance of outcome in Gram-negative bacteraemia, and feedback to prescribers. Local and national surveillance of antibiotic use, resistance and outcomes should be supported and antibiotic prescribing guidelines should be informed by these data. The diagnosis and treatment of both presumptive and confirmed cases of infection by GNB should be improved. This guidance, with infection control to arrest increases in MDR, should be used to improve the outcome of infections with such strains. Anticipated users include medical, scientific, nursing, antimicrobial pharmacy and paramedical staff where they can be adapted for local use