An assessment of Evans' unified field theory I

Evans developed a classical unified field theory of gravitation and electromagnetism on the background of a spacetime obeying a Riemann-Cartan geometry. This geometry can be characterized by an orthonormal coframe theta and a (metric compatible) Lorentz connection Gamma. These two potentials yield the field strengths torsion T and curvature R. Evans tried to infuse electromagnetic properties into this geometrical framework by putting the coframe theta to be proportional to four extended electromagnetic potentials A; these are assumed to encompass the conventional Maxwellian potential in a suitable limit. The viable Einstein-Cartan(-Sciama-Kibble) theory of gravity was adopted by Evans to describe the gravitational sector of his theory. Including also the results of an accompanying paper by Obukhov and the author, we show that Evans' ansatz for electromagnetism is untenable beyond repair both from a geometrical as well as from a physical point of view. As a consequence, his unified theory is obsolete.Comment: 39 pages of latex, modified because of referee report, mistakes and typos removed, partly reformulated, taken care of M.W.Evans' rebutta

Incidents during out-of-hospital patient transportation

Publisher's copy made available with the permission of the publisher © Australian Society of AnaesthetistsOut-of-hospital patient transportation (retrieval) of critically ill patients occurs within highly complex environments. Adverse events are not uncommon. Incident monitoring provides a means to better understand such events. The aim of this study was to characterize incidents occurring during retrieval to provide a basis for developing corrective strategies. Four organizations contributed 125 reports, documenting 272 incidents; 91% of forms documented incidents as preventable. Incidents related to equipment (37%), patient care (26%), transport operations (11%), interpersonal communication (9%), planning or preparation (9%), retrieval staff (7%) and tasking (2%). Incidents occurred during patient transport to the receiving facility (26%), at patient origin (26%), during patient loading (20%), at the retrieval service base (18%) and receiving facility (9%). Contributing factors were system-based for 54% and human-based for 42%. Haste (7.5%), equipment malfunctioning (7.2%) or missing (5.5%), failure to check (5.8%) and pressure to proceed (5.2%) were the most frequent contributing factors. Harm was documented in 59% of incidents with one death. Minimizing factors were good crew skills/teamwork (42%), checking equipment (17%) and patient (8%), patient monitors (15%), good luck (14%) and good interpersonal communication (4%). Incident monitoring provides sufficient insight into retrieval incidents to be a useful quality improvement tool for retrieval services. Information gathered suggested improvements in retrieval equipment design and use of alternative power sources, the use of pro formae for equipment checking, patient assessment, preparation for transportation and information transfer. Lessons from incidents in other areas applicable to retrieval should be linked for analysis with retrieval incidents.A. Flabouris, W. B. Runciman, B. Levingshttp://www.aaic.net.au/Article.asp?D=200530

Summary of the EU project GEISER on induced seismicity in geothermal engineering

GEISER was a European project on understanding and mitigation of induced seismicty in geothermal operations. The project involved several European research institutions as well as industry and was funded by the European Commission within FP7. GEISER addressed a better understanding of the key parameters that control induced seismicity in response to an injection. Data from several events of induced seismicity were collected and analysed. Mechanical models were developed to understand the processes leading to induced seismicity and were combined with probabilistic seismic hazard assessment approaches to propose a new, physics based probabilistic forewarning system. This system requires the determination of a maximum acceptable seismic magnitude and its accepted probability of occurrence. The reliability of the dynamic model is based on the availability of rock physics and seismic data, with models updated from real-time monitoring. In addition to this new approach, a number of recommendations and guidelines for licensing authorities, developers and operators of geothermal projects are proposed

Can venous-to-arterial carbon dioxide differences reflect microcirculatory alterations in patients with septic shock?

Purpose: Septic shock has been associated with microvascular alterations and these in turn with the development of organ dysfunction. Despite advances in video microscopic techniques, evaluation of microcirculation at the bedside is still limited. Venous-to-arterial carbon dioxide difference (Pv-aCO2) may be increased even when venous O2 saturation (SvO2) and cardiac output look normal, which could suggests microvascular derangements. We sought to evaluate whether Pv-aCO2 can reflect the adequacy of microvascular perfusion during the early stages of resuscitation of septic shock. Methods: Prospective observational study including 75 patients with septic shock in a 60-bed mixed ICU. Arterial and mixed-venous blood gases and hemodynamic variables were obtained at catheter insertion (T0) and 6 h after (T6). Using a sidestream dark-field device, we simultaneously acquired sublingual microcirculatory images for blinded semiquantitative analysis. Pv-aCO2 was defined as the difference between mixed-venous and arterial CO2 partial pressures. Results: Progressively lower percentages of small perfused vessels (PPV), lower functional capillary density, and higher heterogeneity of microvascular blood flow were observed at higher Pv-aCO2 values at both T0 and T6. Pv-aCO2 was significantly correlated to PPV (T0: coefficient −5.35, 95 % CI −6.41 to −4.29, p < 0.001; T6: coefficient, −3.49, 95 % CI −4.43 to −2.55, p < 0.001) and changes in Pv-aCO2 between T0 and T6 were significantly related to changes in PPV (R2 = 0.42, p < 0.001). Absolute values and changes in Pv-aCO2 were not related to global hemodynamic variables. Good agreement between venous-to-arterial CO2 and PPV was maintained even after corrections for the Haldane effect. Conclusions: During early phases of resuscitation of septic shock, Pv-aCO2 could reflect the adequacy of microvascular blood flow.SCOPUS: ar.jinfo:eu-repo/semantics/publishe