Fracture dolomite as an archive of continental palaeo-environmental conditions

The origin of Quaternary dolomites in continental environments (e.g. karst and lakes) is barely constrained compared to marine dolomites in sedimentary records. Here we present a study of dolomite and aragonite formations infilling young fractures of the ‘Erzberg’ iron ore deposit, Austria, under continental-meteoric and low temperature conditions. Two dolomite generations formed shortly after the Last Glacial Maximum (~20 kyr BP): dolomite spheroids and matrix dolomite. Clumped isotope measurements and U/Th disequilibrium ages reveal formation temperatures of 0–3 °C (±6 °C) and 3–20 °C (±5 °C) for the both dolomite types, and depositional ages around 19.21 ± 0.10 kyr BP and 13.97 ± 0.08 kyr BP or younger, respectively. Meteoric solution and carbonate isotope compositions (δ18O, δ13C and 87Sr/86Sr) indicate the dolomites formed via aragonite and high-Mg calcite precursors from CO2-degassed, Mg-rich solutions. Our study introduces low temperature dolomite formations and their application as a sedimentary-chemical archive.ISSN:2662-443

Abbreviated and comprehensive literature searches led to identical or very similar effect estimates: a meta-epidemiological study

OBJECTIVES The objective of this study was to assess the agreement of treatment effect estimates from meta-analyses based on abbreviated or comprehensive literature searches. STUDY DESIGN AND SETTING This was a meta-epidemiological study. We abbreviated 47 comprehensive Cochrane review searches and searched MEDLINE/Embase/CENTRAL alone, in combination, with/without checking references (658 new searches). We compared one meta-analysis from each review with recalculated ones based on abbreviated searches. RESULTS The 47 original meta-analyses included 444 trials (median 6 per review interquartile range (IQR) 3-11) with 360045 participants (median 1,371 per review IQR 685-8,041). Depending on the search approach, abbreviated searches led to identical effect estimates in 34-79{\%} of meta-analyses, to different effect estimates with the same direction and level of statistical significance in 15-51{\%}, and to opposite effects (or effects could not be estimated anymore) in 6-13{\%}. The deviation of effect sizes was zero in 50{\%} of the meta-analyses and in 75{\%} not larger than 1.07-fold. Effect estimates of abbreviated searches were not consistently smaller or larger (median ratio of odds ratio 1 IQR 1-1.01) but more imprecise (1.02-1.06-fold larger standard errors). CONCLUSION Abbreviated literature searches often led to identical or very similar effect estimates as comprehensive searches with slightly increased confidence intervals. Relevant deviations may occur

miR-19a-3p containing exosomes improve function of ischemic myocardium upon shock wave therapy

AIMS: As many current approaches for heart regeneration exert unfavorable side-effects, the induction of endogenous repair mechanisms in ischemic heart disease is of particular interest. Recently, exosomes carrying angiogenic miRNAs have been described to improve heart function. However, it remains challenging to stimulate specific release of reparative exosomes in ischemic myocardium. In the present study, we sought to test the hypothesis that the physical stimulus of shock wave therapy (SWT) causes the release of exosomes. We aimed to substantiate the pro-angiogenic impact of the released factors, to identify the nature of their cargo, and to test their efficacy in vivo supporting regeneration and recovery after myocardial ischemia. METHODS AND RESULTS: Mechanical stimulation of ischemic muscle via SWT caused extracellular vesicle (EV) release from endothelial cells both in vitro and in vivo. Characterization of EVs via electron microscopy, nanoparticle tracking analysis and flow cytometry revealed specific exosome morphology and size with presence of exosome markers CD 9, CD81 and CD63. Exosomes exhibited angiogenic properties activating protein kinase b (Akt) and extracellular-signal regulated kinase (ERK) resulting in enhanced endothelial tube formation and proliferation. A miRNA array and transcriptome analysis via next-generation sequencing were performed to specify exosome content. miR-19a-3p was identified as responsible cargo, antimir-19a-3p antagonized angiogenic exosome effects. Exosomes and target miRNA were injected intramyocardially in mice after left anterior descending artery (LAD) ligation. Exosomes resulted in improved vascularization, decreased myocardial fibrosis and increased left ventricular ejection fraction as shown by transthoracic echocardiography. CONCLUSIONS: The mechanical stimulus of SWT causes release of angiogenic exosomes. miR-19a-3p is the vesicular cargo responsible for the observed effects. Released exosomes induce angiogenesis, decrease myocardial fibrosis and improve left ventricular function after myocardial ischemia. Exosome release via SWT could develop an innovative approach for the regeneration of ischemic myocardium

Performance of the CMS Cathode Strip Chambers with Cosmic Rays

The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

Performance and Operation of the CMS Electromagnetic Calorimeter

The operation and general performance of the CMS electromagnetic calorimeter using cosmic-ray muons are described. These muons were recorded after the closure of the CMS detector in late 2008. The calorimeter is made of lead tungstate crystals and the overall status of the 75848 channels corresponding to the barrel and endcap detectors is reported. The stability of crucial operational parameters, such as high voltage, temperature and electronic noise, is summarised and the performance of the light monitoring system is presented