Critical Phenomena in Neutron Stars I: Linearly Unstable Nonrotating Models

We consider the evolution in full general relativity of a family of linearly unstable isolated spherical neutron stars under the effects of very small, perturbations as induced by the truncation error. Using a simple ideal-fluid equation of state we find that this system exhibits a type-I critical behaviour, thus confirming the conclusions reached by Liebling et al. [1] for rotating magnetized stars. Exploiting the relative simplicity of our system, we are able carry out a more in-depth study providing solid evidences of the criticality of this phenomenon and also to give a simple interpretation of the putative critical solution as a spherical solution with the unstable mode being the fundamental F-mode. Hence for any choice of the polytropic constant, the critical solution will distinguish the set of subcritical models migrating to the stable branch of the models of equilibrium from the set of subcritical models collapsing to a black hole. Finally, we study how the dynamics changes when the numerically perturbation is replaced by a finite-size, resolution independent velocity perturbation and show that in such cases a nearly-critical solution can be changed into either a sub or supercritical. The work reported here also lays the basis for the analysis carried in a companion paper, where the critical behaviour in the the head-on collision of two neutron stars is instead considered [2].Comment: 15 pages, 9 figure

Preparation and characterization of Bi26–2xMn2xMo10O69-d and Bi26.4Mn0.6Mo10–2yMe2yO69-d(Me = V, Fe) solid solutions

Received: 06.06.2017; accepted: 23.06.2017; published: 14.07.2017.Single phase samples of bismuth molybdate, Bi26Mo10O69, doped with Mn on the bismuth sublattice and V, Fe on the molybdenum sublattice were found to crystallize in the triclinic Bi26Mo10O69 structure at low doping levels and in the monoclinic Bi26Mo10O69 structure - at higher dopant concentration. The assumption that all Mn ions have an oxidation state of +2 was confirmed by means of magnetic measurement results analysis using Curie-Weiss law. Conductivity was investigated using impedance spectroscopy. The conductivity of Bi26.4Mn0.6Mo9.6Fe0.4O69-d was 1.2*10-2 S*cm-1 at 973 K and 2.2*10-4 S*cm-1 at 623 K, and the conductivity of Bi26.4Mn0.6Mo9.2V0.8O69-d was 2.2*10-3 S*cm-1 at 973 K and 2.2*10-5 S*cm-1 at 623 K

Blowtooth: a provocative pervasive game for smuggling virtual drugs through real airport security

In this paper we describe a pervasive game, Blowtooth, in which players use their mobile phones to hide virtual drugs on nearby airline passengers in real airport check-in queues. After passing through airport security, the player must find and recover their drugs from the innocent bystanders, without them ever realizing they were involved in the game. The game explores the nature of pervasive game playing in environments that are not, generally, regarded as playful or “fun”. This paper describes the game’s design and implementation as well as an evaluation conducted with participants in real airports. It explores the players’ reactions to the game through questionnaire responses and in-game activity. The technologies used in Blowtooth are, intentionally, simple in order for the enjoyment of the game to be reliant more on the physical environment rather than the enabling technologies. We conclude that situating pervasive games in unexpected and challenging environments, such as international airports, may provide interesting and unique gaming experiences for players. In addition, we argue that pervasive games benefit most from using the specific features and nature of interesting real-world environments rather than focusing on the enabling technologies

Burnout and Quality of Life among Active Member Physicians of the Medical Society of Sedgwick County

Introduction. The medical literature suggests disturbingly high ratesof burnout among US physicians. The objective of this study was todetermine the rates of burnout, other forms of distress, and overallquality of life among physicians in Sedgwick County.Methods.xThe study involved a convenience sample of 197 physicianswho were active member physicians of the Medical Society of SedgwickCounty (MSSC). Between July and August 2018, we surveyed872 physicians who were active members of the MSSC. The surveyassessed manifestations of burnout, symptoms of depression and suicidalideation, fatigue, and quality of life. The authors used standarddescriptive summary statistics, Mann-Whitney U test/independentsamples t-Test, Fisher’s exact test, and correlations to analyze thedata.Results. The participation rate was 44.6%, with 49.5% of therespondents reporting manifestations of burnout. Although 85% ofthe participants rated their overall quality of life as good/very good,45% screened positive for depression, 5% had thoughts of suicideduring the past year, and 44% reported excessive fatigue during thepast week. Those with manifestations of burnout were 2.13 (100%vs 46.9%, p < 0.01) times more likely to report thoughts of suicidalideation, 2.43 (72.6% vs 30.4%; p < 0.001) times more likely to screenpositive for depression, and 1.89 (67.5% vs 35.8%; p < 0.001) timesmore likely to have high degrees of fatigue. All of the participants whohad suicidal ideation reported manifestations of burnout.Conclusions. Burnout was prevalent among active member physiciansof the MSSC. Burnout among the participants was associatedwith symptoms of depression, fatigue, suicidal ideation, and intentionof leaving the medical profession via early retirement and/or careerchange. Kans J Med 2019;12(2):33-39

Successes and Challenges of Optimal Trauma Care for Rural Family Physicians in Kansas

Introduction. Kansas has a regionalized trauma systemwith formal mechanisms for review, however, increasedcommunication with rural providers can uncover opportunitiesfor system process improvement. Therefore, thisqualitative study explored perceptions of family medicinephysicians staffing emergency departments (ED) in rural areas,specifically to determine what is going well and what areasneeded improvement in relation to the trauma system. Methods. A focus group included Kansas rural family physiciansrecruited from a local symposium for family medicinephysicians. Demographic information was collected via surveyprior to the focus group session, which was audiotaped.Research team members read the transcription, identifiedthemes, and grouped the findings into categories for analysis. Results. Seven rural family medicine physicians participated inthe focus group. The majority were male (71%) with the mean age46.71 years. All saw patients in the ED and had treated injuriesdue to agriculture, falls, and motor vehicle collisions. Participantsidentified successes in the adoption and enforcement of standardizedprocesses, specifically through level IV trauma centercertification and staff requirements for Advanced Trauma LifeSupport training. Communication breakdown during patient dischargeand skill maintenance were the most prevalent challenges. Conclusions. Even with an established regionalized traumasystem in the state of Kansas, there continues to be opportunitiesfor improvement. The challenges acknowledged byfocus group participants may not be identified through patientcase reviews (if conducted), therefore tertiary centersshould conduct system reviews with referring hospitals regularlyto improve systemic concerns. KS J Med 2017;10(1):12-16

Flux and Seasonality of Dissolved Organic Matter From the Northern Dvina (Severnaya Dvina) River, Russia

Pan‐Arctic riverine dissolved organic carbon (DOC) fluxes represent a major transfer of carbon from land‐to‐ocean, and past scaling estimates have been predominantly derived from the six major Arctic rivers. However, smaller watersheds are constrained to northern high‐latitude regions and, particularly with respect to the Eurasian Arctic, have received little attention. In this study, we evaluated the concentration of DOC and composition of dissolved organic matter (DOM) via optical parameters, biomarkers (lignin phenols), and ultrahigh resolution mass spectrometry in the Northern Dvina River (a midsized high‐latitude constrained river). Elevated DOC, lignin concentrations, and aromatic DOM indicators were observed throughout the year in comparison to the major Arctic rivers with seasonality exhibiting a clear spring freshet and also some years a secondary pulse in the autumn concurrent with the onset of freezing. Chromophoric DOM absorbance at a350 was strongly correlated to DOC and lignin across the hydrograph; however, the relationships did not fit previous models derived from the six major Arctic rivers. Updated DOC and lignin fluxes were derived for the pan‐Arctic watershed by scaling from the Northern Dvina resulting in increased DOC and lignin fluxes (50 Tg yr−1 and 216 Gg yr−1, respectively) compared to past estimates. This leads to a reduction in the residence time for terrestrial carbon in the Arctic Ocean (0.5 to 1.8 years). These findings suggest that constrained northern high‐latitude rivers are underrepresented in models of fluxes based from the six largest Arctic rivers with important ramifications for the export and fate of terrestrial carbon in the Arctic Ocean