American Mastodon Mitochondrial Genomes Suggest Multiple Dispersal Events in Response to Pleistocene Climate Oscillations

Pleistocene glacial-interglacial cycles are correlated with dramatic temperature oscillations. Examining how species responded to these natural fluctuations can provide valuable insights into the impacts of present-day anthropogenic climate change. Here we present a phylogeographic study of the extinct American mastodon (Mammut americanum), based on 35 complete mitochondrial genomes. These data reveal the presence of multiple lineages within this species, including two distinct clades from eastern Beringia. Our molecular date estimates suggest that these clades arose at different times, supporting a pattern of repeated northern expansion and local extirpation in response to glacial cycling. Consistent with this hypothesis, we also note lower levels of genetic diversity among northern mastodons than in endemic clades south of the continental ice sheets. The results of our study highlight the complex relationships between population dispersals and climate change, and can provide testable hypotheses for extant species expected to experience substantial biogeographic impacts from rising temperatures

In situ measurements of atmospheric O2 and CO2 reveal an unexpected O2 signal over the tropical Atlantic Ocean

We present the first meridional transects of atmospheric O2 and CO2 over the Atlantic Ocean. We combine these measurements into the tracer atmospheric potential oxygen (APO), which is a measure of the oceanic contribution to atmospheric O2 variations. Our new in situ measurement system, deployed on board a commercial container ship during 2015, performs as well as or better than existing similar measurement systems. The data show small short-term variability (hours to days), a step-change corresponding to the position of the Intertropical Convergence Zone (ITCZ), and seasonal cycles that vary with latitude. In contrast to data from the Pacific Ocean and to previous modeling studies, our Atlantic Ocean APO data show no significant bulge in the tropics. This difference cannot be accounted for by interannual variability in the position of the ITCZ or the Atlantic Meridional Mode Index and appears to be a persistent feature of the Atlantic Ocean system. Modeled APO using the TM3 atmospheric transport model does exhibit a significant bulge over the Atlantic and overestimates the interhemispheric gradient in APO over the Atlantic Ocean. These results indicate that either there are inaccuracies in the oceanic flux data products in the equatorial Atlantic Ocean region, or that there are atmospheric transport inaccuracies in the model, or a combination of both. Our shipboard O2 and CO2 measurements are ongoing and will reveal the long-term nature of equatorial APO outgassing over the Atlantic as more data become available

Precision measurements of A1N in the deep inelastic regime

We have performed precision measurements of the double-spin virtual-photon asymmetry A1A1 on the neutron in the deep inelastic scattering regime, using an open-geometry, large-acceptance spectrometer and a longitudinally and transversely polarized 3He target. Our data cover a wide kinematic range 0.277≤x≤0.5480.277≤x≤0.548 at an average Q2Q2 value of 3.078 (GeV/c)2, doubling the available high-precision neutron data in this x range. We have combined our results with world data on proton targets to make a leading-order extraction of the ratio of polarized-to-unpolarized parton distribution functions for up quarks and for down quarks in the same kinematic range. Our data are consistent with a previous observation of anA1n zero crossing near x=0.5x=0.5. We find no evidence of a transition to a positive slope in(Δd+Δd¯)/(d+d¯) up to x=0.548x=0.548

The National Early Warning Score and its subcomponents recorded within ±24 hours of emergency medical admission are poor predictors of hospital-acquired acute kidney injury

YesBackground: Hospital-acquired Acute Kidney Injury (H-AKI) is a common cause of avoidable morbidity and mortality. Aim: To determine if the patients’ vital signs data as defined by a National Early Warning Score (NEWS), can predict H-AKI following emergency admission to hospital. Methods: Analyses of emergency admissions to York hospital over 24-months with NEWS data. We report the area under the curve (AUC) for logistic regression models that used the index NEWS (model A0), plus age and sex (A1), plus subcomponents of NEWS (A2) and two-way interactions (A3). Likewise for maximum NEWS (models B0,B1,B2,B3). Results: 4.05% (1361/33608) of emergency admissions had H-AKI. Models using the index NEWS had the lower AUCs (0.59 to 0.68) than models using the maximum NEWS AUCs (0.75 to 0.77). The maximum NEWS model (B3) was more sensitivity than the index NEWS model (A0) (67.60% vs 19.84%) but identified twice as many cases as being at risk of H-AKI (9581 vs 4099) at a NEWS of 5. Conclusions: The index NEWS is a poor predictor of H-AKI. The maximum NEWS is a better predictor but seems unfeasible because it is only knowable in retrospect and is associated with a substantial increase in workload albeit with improved sensitivity.The Health Foundatio