2,426 research outputs found
Cave deposits as a sedimentary trap for the Marine Isotope Stage 3 environmental record: The case study of Pod Hradem, Czech Republic
Pod Hradem Cave, located in the Moravian Karst, Czech Republic, offers an excellent opportunity for environmental reconstructions of Marine Isotope Stage 3 (MIS 3) in Central Europe due to its detailed sedimentary record dated 50,000 to 28,000 cal BP. Identifying the natural environments of the Middle to Upper Palaeolithic (MUP) transition is necessary to understand the settlement strategies and related behaviour of both Neanderthals and Anatomically Modern Humans, both of whom may have occupied the region at the same time. A multidisciplinary excavation was carried out between 2011 and 2016. Detailed analyses of the sediments, vertebrate microfauna, pollen and charcoal revealed minor but observable fluctuations in climate, with little change in the surrounding vegetation. The Pod Hradem palaeoenvironmental dataset is complex, but generally reflects a predominantly glacial climate with a range of vegetation types and habitats during the Late Pleistocene, followed by the warmer and more humid Holocene. The MUP transition as recorded in Pod Hradem Cave was a glacial environment interrupted by two relatively warmer periods. Central Europe experienced extreme climate fluctuations during MIS3, as recorded from different sedimentary archives, but it seems that the Pod Hradem Cave environment may have acted as a buffer zone, ameliorating those extremes, and providing a suitable refuge for both bears seeking winter hibernation dens and occasionally visiting humans.Thisproject was funded from the SoMoPro programme. Research leading tothese results has received a financial contribution from the EuropeanCommunity within the Seventh Framework Programme (FP/2007–2013) under Grant Agreement No. 229603. The research was alsoco-financed by the South Moravian Region and the Department ofAnthropology & Department of Geological Sciences (departmentalfunding - Masaryk University) and the internal programme of theInstitute of Geology CAS in Prague No. RVO 67985831
Identifying existing Choosing Wisely recommendations of high relevance and importance to hematology
Choosing Wisely (CW) is a medical stewardship initiative led by the American Board of Internal Medicine Foundation in collaboration with professional medical societies in the United States. In an effort to learn from and leverage the work of others, the American Society of Hematology CW Task Force developed a method to identify and prioritize CW recommendations from other medical societies of high relevance and importance to patients with blood disorders and their physicians. All 380 CW recommendations were reviewed and assessed for relevance and importance. Relevance was assessed using the MORE TM relevance scale. Importance was assessed with regard to six guiding principles: harm avoidance, evidence, aggregate cost, relevance, frequency and impact. Harm avoidance was considered the most important principle. Ten highly relevant and important recommendations were identified from a variety of professional societies. Recommendations focused on decreasing unnecessary imaging, blood work, treatments and transfusions, as well as on increasing collaboration across disciplines and considering value when recommending treatments. Many CW recommendations have relevance beyond the society of origin. The methods developed by the ASH CW Task Force could be easily adapted by other Societies to identify additional CW recommendations of relevance and importance to their fields. Am. J. Hematol. 91:787–792, 2016. © 2016 Wiley Periodicals, Inc
Model-independent source imaging using two-pion correlations in 2 to 8A GeV Au + Au collisions
We report a particle source imaging analysis based on two-pion correlations
in high multiplicity Au + Au collisions at beam energies between 2 and 8A GeV.
We apply the imaging technique introduced by Brown and Danielewicz, which
allows a model-independent extraction of source functions with useful accuracy
out to relative pion separations of about 20 fm. The extracted source functions
have Gaussian shapes. Values of source functions at zero separation are almost
constant across the energy range under study. Imaging results are found to be
consistent with conventional source parameters obtained from a multidimensional
HBT analysis.Comment: 4 pages, 3 figure
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Validation and public health modelling of risk prediction models for kidney cancer using the UK Biobank
Funder: Kidney Cancer UKFunder: Yorkshire Cancer ResearchFunder: Mark Foundation For Cancer Research; Id: http://dx.doi.org/10.13039/100014599Funder: The Rosetrees TrustFunder: Urology Foundation; Id: http://dx.doi.org/10.13039/501100007568Objectives: To externally validate risk models for the detection of kidney cancer, as early detection of kidney cancer improves survival and stratifying the population using risk models could enable an individually tailored screening programme. Methods: We validated the performance of 30 existing phenotypic models predicting the risk of kidney cancer in the UK Biobank cohort (n = 450 687). We compared the discrimination and calibration of models for men, women, and a mixed‐sex cohort. Population level data were used to estimate model performance in a screening scenario for a range of risk thresholds (6‐year risk: 0.1–1.0%). Results: In all, 10 models had reasonable discrimination (area under the receiver‐operating characteristic curve >0.60), although some had poor calibration. Modelling demonstrated similar performance of the best models over a range of thresholds. The models showed an improvement in ability to identify cases compared to age‐ and sex‐based screening. All the models performed less well in women than men. Conclusions: The present study is the first comprehensive external validation of risk models for kidney cancer. The best‐performing models are better at identifying individuals at high risk of kidney cancer than age and sex alone; however, the benefits are relatively small. Feasibility studies are required to determine applicability to a screening programme
Calibration of myocardial T2 and T1 against iron concentration.
BACKGROUND: The assessment of myocardial iron using T2* cardiovascular magnetic resonance (CMR) has been validated and calibrated, and is in clinical use. However, there is very limited data assessing the relaxation parameters T1 and T2 for measurement of human myocardial iron.
METHODS: Twelve hearts were examined from transfusion-dependent patients: 11 with end-stage heart failure, either following death (n=7) or cardiac transplantation (n=4), and 1 heart from a patient who died from a stroke with no cardiac iron loading. Ex-vivo R1 and R2 measurements (R1=1/T1 and R2=1/T2) at 1.5 Tesla were compared with myocardial iron concentration measured using inductively coupled plasma atomic emission spectroscopy.
RESULTS: From a single myocardial slice in formalin which was repeatedly examined, a modest decrease in T2 was observed with time, from mean (± SD) 23.7 ± 0.93 ms at baseline (13 days after death and formalin fixation) to 18.5 ± 1.41 ms at day 566 (p<0.001). Raw T2 values were therefore adjusted to correct for this fall over time. Myocardial R2 was correlated with iron concentration [Fe] (R2 0.566, p<0.001), but the correlation was stronger between LnR2 and Ln[Fe] (R2 0.790, p<0.001). The relation was [Fe] = 5081•(T2)-2.22 between T2 (ms) and myocardial iron (mg/g dry weight). Analysis of T1 proved challenging with a dichotomous distribution of T1, with very short T1 (mean 72.3 ± 25.8 ms) that was independent of iron concentration in all hearts stored in formalin for greater than 12 months. In the remaining hearts stored for <10 weeks prior to scanning, LnR1 and iron concentration were correlated but with marked scatter (R2 0.517, p<0.001). A linear relationship was present between T1 and T2 in the hearts stored for a short period (R2 0.657, p<0.001).
CONCLUSION: Myocardial T2 correlates well with myocardial iron concentration, which raises the possibility that T2 may provide additive information to T2* for patients with myocardial siderosis. However, ex-vivo T1 measurements are less reliable due to the severe chemical effects of formalin on T1 shortening, and therefore T1 calibration may only be practical from in-vivo human studies
Longitudinal Flow of Protons from 2-8 AGeV Central Au+Au Collisions
Rapidity distributions of protons from central Au + Au
collisions measured by the E895 Collaboration in the energy range from 2 to 8
AGeV at the Brookhaven AGS are presented. Longitudinal flow parameters derived
using a thermal model including collective longitudinal expansion are extracted
from these distributions. The results show an approximately linear increase in
the longitudinal flow velocity, , as a function of the
logarithm of beam energy.Comment: 5 Pages, including 3 figures, 1 tabl
Near-threshold production of the multi-strange hyperon
The yield for the multi-strange hyperon has been measured in 6 AGeV
Au+Au collisions via reconstruction of its decay products and
, the latter also being reconstructed from its daughter tracks of
and p. The measurement is rather close to the threshold for
production and therefore provides an important test of model predictions. The
measured yield for and are compared for several
centralities. In central collisions the yield is found to be in
excellent agreement with statistical and transport model predictions,
suggesting that multi-strange hadron production approaches chemical equilibrium
in high baryon density nuclear matter.Comment: Submitted to PR
Comparison of Source Images for protons, 's and 's in 6 AGeV Au+Au collisions
Source images are extracted from two-particle correlations constructed from
strange and non-strange hadrons produced in 6 AGeV Au + Au collisions. Very
different source images result from pp vs p vs
correlations. These observations suggest important differences in the
space-time emission histories for protons, pions and neutral strange baryons
produced in the same events
Laying the groundwork at the AGS: Recent results from experiment E895
The E895 Collaboration at the Brookhaven AGS has performed a systematic
investigation of Au+Au collisions at 2-8 AGeV, using a large-acceptance Time
Projection Chamber. In addition to extensive measurements of particle flow,
spectra, two-particle interferometry, and strangeness production, we have
performed novel hybrid analyses, including azimuthally-sensitive pion HBT,
extraction of the six-dimensional pion phasespace density, and a first
measurement of the Lambda-proton correlation function.Comment: Presented at Quark Matter 2001, 8 pages, 5 figure
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