SImulator of GAlaxy Millimetre/submillimetre Emission (SIGAME): CO emission from massive z=2 main-sequence galaxies

We present SIGAME (SImulator of GAlaxy Millimetre/submillimetre Emission), a new numerical code designed to simulate the 12CO rotational line emission spectrum of galaxies. Using sub-grid physics recipes to post-process the outputs of smoothed particle hydrodynamics (SPH) simulations, a molecular gas phase is condensed out of the hot and partly ionized SPH gas. The gas is subjected to far-UV radiation fields and cosmic ray ionization rates which are set to scale with the local star formation rate volume density. Level populations and radiative transport of the CO lines are solved with the 3-D radiative transfer code LIME. We have applied SIGAME to cosmological SPH simulations of three disc galaxies at z=2 with stellar masses in the range ~(0.5-2)x10^11 Msun and star formation rates ~40-140 Msun/yr. Global CO luminosities and line ratios are in agreement with observations of disc galaxies at z~2 up to and including J=3-2 but falling short of the few existing J=5-4 observations. The central 5 kpc regions of our galaxies have CO 3-2/1-0 and 7-6/1-0 brightness temperature ratios of ~0.55-0.65 and ~0.02-0.08, respectively, while further out in the disc the ratios drop to more quiescent values of ~0.5 and <0.01. Global CO-to-H2 conversion (alpha_CO) factors are ~=1.5 Msun*pc^2/(K km s/1), i.e. ~2-3 times below typically adopted values for disc galaxies, and alpha_CO increases with radius, in agreement with observations of nearby galaxies. Adopting a top-heavy Giant Molecular Cloud (GMC) mass spectrum does not significantly change the results. Steepening the GMC density profile leads to higher global line ratios for J_up>=3 and CO-to-H2 conversion factors [~=3.6 Msun*pc^2/(K km/s)].Comment: 28 pages, 20 figures. Accepted for Publication in MNRAS. Substantial revisions from the previous version, including tests with model galaxies similar to the Milky Way. Improved figures and added table

Effect of virtual reality training on laparoscopic surgery: randomised controlled trial

Objective To assess the effect of virtual reality training on an actual laparoscopic operation

Snow‐Atmosphere Humidity Exchange at the Ice Sheet Surface Alters Annual Mean Climate Signals in Ice Core Records

Surface processes alter the water stable isotope signal of the surface snow after deposition. However, it remains an open question to which extent surface post-depositional processes should be considered when inferring past climate information from ice core records. Here, we present simulations for the Greenland Ice Sheet, combining outputs from two climate models with an isotope-enabled snowpack model. We show that surface vapor exchange and associated fractionation imprint a climate signal into the firn, resulting in an increase in the annual mean value of δ18O by +2.3‰ and a reduction in d-excess by −6.3‰. Further, implementing isotopic fractionation during surface vapor exchange improves the representation of the observed seasonal amplitude in δ18O from 65.0% to 100.2%. Our results stress that surface vapor exchange is important in the climate proxy signal formation and needs consideration when interpreting ice core climate records

Ultraearly thrombolysis by an anesthesiologist in a mobile stroke unit: A prospective, controlled intervention study

Background Acute stroke treatment in mobile stroke units (MSU) is feasible and reduces time-to-treatment, but the optimal staffing model is unknown. We wanted to explore if integrating thrombolysis of acute ischemic stroke (AIS) in an anesthesiologist-based emergency medical services (EMS) reduces time-to-treatment and is safe. Methods A nonrandomized, prospective, controlled intervention study. Inclusion criteria: age ≥18 years, nonpregnant, stroke symptoms with onset ≤4 h. The MSU staffing is inspired by the Norwegian Helicopter Emergency Medical Services crew with an anesthesiologist, a paramedic-nurse and a paramedic. Controls were included by conventional ambulances in the same catchment area. Primary outcome was onset-to-treatment time. Secondary outcomes were alarm-to-treatment time, thrombolytic rate and functional outcome. Safety outcomes were symptomatic intracranial hemorrhage and mortality. Results We included 440 patients. MSU median (IQR) onset-to-treatment time was 101 (71–155) minutes versus 118 (90–176) minutes in controls, p = 0.007. MSU median (IQR) alarm-to-treatment time was 53 (44–65) minutes versus 74 (63–95) minutes in controls, p < 0.001. Golden hour treatment was achieved in 15.2% of the MSU patients versus 3.7% in the controls, p = 0.005. The thrombolytic rate was higher in the MSU (81% vs 59%, p = 0.001). MSU patients were more often discharged home (adjusted OR [95% CI]: 2.36 [1.11–5.03]). There were no other significant differences in outcomes. Conclusions Integrating thrombolysis of AIS in the anesthesiologist-based EMS reduces time-to-treatment without negatively affecting outcomes. An MSU based on the EMS enables prehospital assessment of acute stroke in addition to other medical and traumatic emergencies and may facilitate future implementation.publishedVersio

Instructor feedback versus no instructor feedback on performance in a laparoscopic virtual reality simulator: a randomized educational trial

<p>Abstract</p> <p>Background</p> <p>Several studies have found a positive effect on the learning curve as well as the improvement of basic psychomotor skills in the operating room after virtual reality training. Despite this, the majority of surgical and gynecological departments encounter hurdles when implementing this form of training. This is mainly due to lack of knowledge concerning the time and human resources needed to train novice surgeons to an adequate level. The purpose of this trial is to investigate the impact of instructor feedback regarding time, repetitions and self-perception when training complex operational tasks on a virtual reality simulator.</p> <p>Methods/Design</p> <p>The study population consists of medical students on their 4^thto 6^thyear without prior laparoscopic experience. The study is conducted in a skills laboratory at a centralized university hospital. Based on a sample size estimation 98 participants will be randomized to an intervention group or a control group. Both groups have to achieve a predefined proficiency level when conducting a laparoscopic salpingectomy using a surgical virtual reality simulator. The intervention group receives standardized instructor feedback of 10 to 12 min a maximum of three times. The control group receives no instructor feedback. Both groups receive the automated feedback generated by the virtual reality simulator. The study follows the CONSORT Statement for randomized trials. Main outcome measures are time and repetitions to reach the predefined proficiency level on the simulator. We include focus on potential sex differences, computer gaming experience and self-perception.</p> <p>Discussion</p> <p>The findings will contribute to a better understanding of optimal training methods in surgical education.</p> <p>Trial Registration</p> <p><a href="http://www.clinicaltrials.gov/ct2/show/NCT01497782">NCT01497782</a></p