CPT, T, and Lorentz Violation in Neutral-Meson Oscillations

Tests of CPT and Lorentz symmetry using neutral-meson oscillations are studied within a formalism that allows for indirect CPT and T violation of arbitrary size and is independent of phase conventions. The analysis is particularly appropriate for studies of CPT and T violation in oscillations of the heavy neutral mesons D, B_d, and B_s. The general Lorentz- and CPT-breaking standard-model extension is used to derive an expression for the parameter for CPT violation. It varies in a prescribed way with the magnitude and orientation of the meson momentum and consequently also with sidereal time. Decay probabilities are presented for both uncorrelated and correlated mesons, and some implications for experiments are discussed.Comment: 11 pages, references added, accepted in Physical Review

Sinks for nitrogen inputs in terrestrial ecosystems: a meta-analysis of15N tracer field studies

Effects of anthropogenic nitrogen (N) deposition and the ability of terrestrial ecosystems to store carbon (C) depend in part on the amount of N retained in the system and its partitioning among plant and soil pools. We conducted a meta-analysis of studies at 48 sites across four continents that used enriched 15N isotope tracers in order to synthesize information about total ecosystem N retention (i.e., total ecosystem 15N recovery in plant and soil pools) across natural systems and N partitioning among ecosystem pools. The greatest recoveries of ecosystem 15N tracer occurred in shrublands (mean, 89.5%) and wetlands (84.8%) followed by forests (74.9%) and grasslands (51.8%). In the short term (<1 week after 15N tracer application), total ecosystem 15N recovery was negatively correlated with fine-root and soil 15N natural abundance, and organic soil C and N concentration but was positively correlated with mean annual temperature and mineral soil C:N. In the longer term (3–18 months after 15N tracer application), total ecosystem 15N retention was negatively correlated with foliar natural-abundance 15N but was positively correlated with mineral soil C and N concentration and C : N, showing that plant and soil natural-abundance 15N and soil C:N are good indicators of total ecosystem N retention. Foliar N concentration was not significantly related to ecosystem 15N tracer recovery, suggesting that plant N status is not a good predictor of total ecosystem N retention. Because the largest ecosystem sinks for 15N tracer were below ground in forests, shrublands, and grasslands, we conclude that growth enhancement and potential for increased C storage in aboveground biomass from atmospheric N deposition is likely to be modest in these ecosystems. Total ecosystem 15N recovery decreased with N fertilization, with an apparent threshold fertilization rate of 46 kg N·ha−1·yr−1 above which most ecosystems showed net losses of applied 15N tracer in response to N fertilizer additio

E-learning in advanced life support--an evaluation by the Resuscitation Council (UK).

AIM To descriptively analyse the outcomes following the national roll out of an e-Learning advanced life support course (e-ALS) compared to a conventional 2-day ALS course (c-ALS). METHOD Between 1st January 2013 and 30th June 2014, 27,170 candidates attended one of the 1350 Resuscitation Council (UK) ALS courses across the UK. 18,952 candidates were enrolled on a c-ALS course and 8218 on an e-ALS course. Candidates participating in the e-ALS course completed 6-8h of online e-Learning prior to attending the 1 day modified face-to-face course. Candidates participating in the c-ALS course undertook the Resuscitation Council (UK) 2-day face-to-face course. All candidates were assessed by a pre- and post-course MCQ and a practical cardiac arrest simulation (CAS-test). Demographic data were collected in addition to assessment outcomes. RESULTS Candidates on the e-ALS course had higher scores on the pre-course MCQ (83.7%, SD 7.3) compared to those on the c-ALS course (81.3%, SD 8.2, P<0.001). Similarly, they had slightly higher scores on the post-course MCQ (e-ALS 87.9%, SD 6.4 vs. c-ALS 87.4%, SD 6.5; P<0.001). The first attempt CAS-test pass rate on the e-ALS course was higher than the pass rate on the c-ALS course (84.6% vs. 83.6%; P=0.035). The overall pass rate was 96.6% on both the e-ALS and c-ALS courses (P=0.776). CONCLUSION The e-ALS course demonstrates equivalence to traditional face-to-face learning in equipping candidates with ALS skills when compared to the c-ALS course. Value is added when considering benefits such as increased candidate autonomy, cost-effectiveness, decreased instructor burden and improved standardisation of course material. Further dissemination of the e-ALS course should be encouraged