410 research outputs found
Tracking the sea-level signature of the 8.2 ka cooling event: New constraints from the Mississippi Delta
The ever increasing need for accurate predictions of global environmental change under greenhouse conditions has sparked immense interest in an abrupt, century‐scale cooling around 8200 years ago, with a focal point in the North Atlantic and with hemispheric teleconnections. Despite considerable progress in the unraveling of this striking feature, including a conceivable driving mechanism (rapid drainage of proglacial Lake Agassiz/Ojibway and a resulting reduced strength of North Atlantic thermohaline circulation), several key questions remain unanswered. One salient aspect concerns the total amount of freshwater released during this catastrophic event, likely echoed by a near‐instantaneous eustatic sea‐level rise. So far, no attempts have been made to perform high‐resolution sea‐level studies that explicitly focus on this critical time interval. Here, we present new data from the Mississippi Delta suggestive of abrupt sea‐level rise associated with the 8.2 ka event. However, the amount of sea‐level rise was likely less than ∼1.2 m, corresponding to a meltwater volume of less than ∼4.3 1014 m3; values lower than estimates used by several recent studies
Vascular aging in long-term survivors of testicular cancer more than 20 years after treatment with cisplatin-based chemotherapy
Background: Late effects of cisplatin-based chemotherapy in testicular cancer survivors (TCS) include cardiovascular morbidity, but little data is available beyond 20 years. The objective was to assess vascular damage in very long-term TCS. Methods: TCS (treated with chemotherapy or orchiectomy only) and age-matched healthy controls were invited. Study assessment included vascular stiffness with ultrasound measurement of carotid-femoral pulse wave velocity (cf-PWV). Results: We included 127 TCS consisting of a chemotherapy group (70 patients) and an orchiectomy group (57 patients) along with 70 controls. Median follow-up was 28 years (range: 20–42). The cf-PWV (m/s) was higher in TCS than in controls (geometrical mean 8.05 (SD 1.23) vs. 7.60 (SD 1.21), p = 0.04). The cf-PWV was higher in the chemotherapy group than in the orchiectomy group (geometrical mean 8.39 (SD 1.22) vs. 7.61 (SD 1.21), p < 0.01). In the chemotherapy group cf-PWV increased more rapidly as a function of age compared to controls (regression coefficient b 7.59 × 10−3 vs. 4.04 × 10−3; p = 0.03). Conclusion: Very long-term TCS treated with cisplatin-based chemotherapy show increased vascular damage compatible with “accelerated vascular aging” and continue to be at risk for cardiovascular morbidity, thus supporting the need for intensive cardiovascular risk management. Clinical trial registration: The clinical trial registration number is NCT02572934
Measuring underreporting and under-ascertainment in infectious disease datasets: a comparison of methods
Gibbons CL, Mangen M-JJ, Plaß D, et al. Measuring underreporting and under-ascertainment in infectious disease datasets: a comparison of methods. BMC Public Health. 2014;14(1): 147.Background: Efficient and reliable surveillance and notification systems are vital for monitoring public health and disease outbreaks. However, most surveillance and notification systems are affected by a degree of underestimation (UE) and therefore uncertainty surrounds the 'true' incidence of disease affecting morbidity and mortality rates. Surveillance systems fail to capture cases at two distinct levels of the surveillance pyramid: from the community since not all cases seek healthcare (under-ascertainment), and at the healthcare-level, representing a failure to adequately report symptomatic cases that have sought medical advice (underreporting). There are several methods to estimate the extent of under-ascertainment and underreporting. Methods: Within the context of the ECDC-funded Burden of Communicable Diseases in Europe (BCoDE)-project, an extensive literature review was conducted to identify studies that estimate ascertainment or reporting rates for salmonellosis and campylobacteriosis in European Union Member States (MS) plus European Free Trade Area (EFTA) countries Iceland, Norway and Switzerland and four other OECD countries (USA, Canada, Australia and Japan). Multiplication factors (MFs), a measure of the magnitude of underestimation, were taken directly from the literature or derived (where the proportion of underestimated, under-ascertained, or underreported cases was known) and compared for the two pathogens. Results: MFs varied between and within diseases and countries, representing a need to carefully select the most appropriate MFs and methods for calculating them. The most appropriate MFs are often disease-,country-, age-, and sex-specific. Conclusions: When routine data are used to make decisions on resource allocation or to estimate epidemiological parameters in populations, it becomes important to understand when, where and to what extent these data represent the true picture of disease, and in some instances (such as priority setting) it is necessary to adjust for underestimation. MFs can be used to adjust notification and surveillance data to provide more realistic estimates of incidence
Combined Forward-Backward Asymmetry Measurements in Top-Antitop Quark Production at the Tevatron
The CDF and D0 experiments at the Fermilab Tevatron have measured the asymmetry between yields of forward- and backward-produced top and antitop quarks based on their rapidity difference and the asymmetry between their decay leptons. These measurements use the full data sets collected in proton-antiproton collisions at a center-of-mass energy of TeV. We report the results of combinations of the inclusive asymmetries and their differential dependencies on relevant kinematic quantities. The combined inclusive asymmetry is . The combined inclusive and differential asymmetries are consistent with recent standard model predictions
Retrospective evaluation of whole exome and genome mutation calls in 746 cancer samples
Funder: NCI U24CA211006Abstract: The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) curated consensus somatic mutation calls using whole exome sequencing (WES) and whole genome sequencing (WGS), respectively. Here, as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, which aggregated whole genome sequencing data from 2,658 cancers across 38 tumour types, we compare WES and WGS side-by-side from 746 TCGA samples, finding that ~80% of mutations overlap in covered exonic regions. We estimate that low variant allele fraction (VAF < 15%) and clonal heterogeneity contribute up to 68% of private WGS mutations and 71% of private WES mutations. We observe that ~30% of private WGS mutations trace to mutations identified by a single variant caller in WES consensus efforts. WGS captures both ~50% more variation in exonic regions and un-observed mutations in loci with variable GC-content. Together, our analysis highlights technological divergences between two reproducible somatic variant detection efforts
Gas analyses, fluid inclusions and stable isotopes of the Panasqueira W-Sn deposits, Portugal
Fluid pressures up to 1000 bars higher than the lithostatic pressure existed in the early stage before formation of the Panasqueira W-Sn deposits. Opening of the sub-horizontal joint system resulted in a drastic pressure drop and boiling of the ore fluids. Ore deposits were formed from 'magmatic' fluids, which contained substantial amounts of N2 and CH4 from assimilated sediments in the magma. Only in the latest stage an apparent influx of meteoric water changed the 'magmatic' composition of the fluid.Des pressions fluides environ 1000 bars plus hautes que la pression lithostatique, existaient dans le stade initial, avant la formation des gisements W-Sn de Panasqueira. L'ouverture des diaclases sub-horizontales a produit une chute de pression accompagnée par une ébullition violente des fluides minéralisateurs. Le minerai est déposé par des fluides d'origine magmatique et riches en N2 et CH4, provenant des sédiments assimilés dans le magma. Ce n'était qu'au dernier stade de formation que l'addition d'eau météorique a changé la composition des fluides.Bussink Rudolf Willem, Kreulen Rob, Jong Arie F. M. de. Gas analyses, fluid inclusions and stable isotopes of the Panasqueira W-Sn deposits, Portugal. In: Bulletin de Minéralogie, volume 107, 6, 1984. pp. 703-713
Contamination and Fractionation Effects in AMS-Measured 14
From the 16th International Radiocarbon Conference held in Gronigen, Netherlands, June 16-20, 1997.In AMS measurements on small (m is lesser than or equal to 400 micrograms) carbon samples, an m-dependence has been noted for the 14C/12C and 13C/12C ratios that is due to the combined effect of contamination and fractionation. A simple formalism is presented to describe the phenomena and to correct measurements on unknowns for their effect.This material was digitized as part of a cooperative project between Radiocarbon and the University of Arizona Libraries.The Radiocarbon archives are made available by Radiocarbon and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform February 202
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Contamination and Fractionation Effects in AMS-Measured 14C/12C and 13C/12C Ratios of Small Samples
From the 16th International Radiocarbon Conference held in Gronigen, Netherlands, June 16-20, 1997.In AMS measurements on small (m is lesser than or equal to 400 micrograms) carbon samples, an m-dependence has been noted for the 14C/12C and 13C/12C ratios that is due to the combined effect of contamination and fractionation. A simple formalism is presented to describe the phenomena and to correct measurements on unknowns for their effect.This material was digitized as part of a cooperative project between Radiocarbon and the University of Arizona Libraries.The Radiocarbon archives are made available by Radiocarbon and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform February 202
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Radiocarbon Dating of Several Ancient Jewish Oil Lamps from Rome
In this paper, we discuss how the radiocarbon dating of soot on oil lamps can help determine the chronology of the Jewish catacombs of Rome. We also explore the ramifications of our work for the typological study of Roman period terracotta lamps.The Radiocarbon archives are made available by Radiocarbon and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform February 202
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