119 research outputs found
Investigation of catalytic reduction and filter techniques for simultaneous measurements of NO, NO2, and HNO3 in the stratosphere
A concept for measuring stratospheric NOy-species is presented which utilizes the catalytic reduction of NO2 and HNO3 over heated metal catalysts and the chemisorption of HNO3 on Nylon. Using the Max Planck Institute for Aeronomy (MPAE) chemiluminescent balloon-borne sonde, stratospheric NO and NO2 profiles have been measured since 1983. NO is detected by chemiluminescence produced in reaction with O3 while NO2 needs first to be converted to NO over a heated stainless steel catalyst. To improve this technique for simultaneously measuring HNO3, the catalytic reduction of NO2 and HNO3 over several metal catalysts and the chemisorption of NO2 and HNO3 on Nylon have been investigated in laboratory tests. The results of these tests under simulated stratospheric conditions are presented in detail in this paper. They demonstrate that the simultaneous measurement of NO, NO2 and HNO3 is indeed possible with the combination of stainless steel or Au as a catalyst and a nylon filter
Discovery of an old nova remnant in the Galactic globular cluster M 22
A nova is a cataclysmic event on the surface of a white dwarf in a binary
system that increases the overall brightness by several orders of magnitude.
Although binary systems with a white dwarf are expected to be overabundant in
globular clusters (GCs) compared to the Galaxy, only two novae from Galactic
globular clusters have been observed. We present the discovery of an emission
nebula in the Galactic globular cluster M 22 (NGC 6656) in observations made
with the integral-field spectrograph MUSE. We extract the spectrum of the
nebula and use the radial velocity determined from the emission lines to
confirm that the nebula is part of NGC 6656. Emission-line ratios are used to
determine the electron temperature and density. It is estimated to have a mass
of 1 to solar masses. This mass and the emission-line
ratios indicate that the nebula is a nova remnant. Its position coincides with
the reported location of a 'guest star', an ancient Chinese term for
transients, observed in May 48 BCE. With this discovery, this nova may be one
of the oldest confirmed extrasolar events recorded in human history.Comment: 7 pages, 3 figures; accepted for publication in Astronomy &
Astrophysic
Urinary [TIMP-2]*[IGFBP7] for early prediction of acute kidney injury after coronary artery bypass surgery
Erratum to: ‘Early prediction of acute kidney injury after transapical and transaortic aortic valve implantation with urinary G1 cell cycle arrest biomarkers’
Background: Acute kidney injury (AKI) is a common complication following transcatheter aortic valve implantation (TAVI) leading to increased mortality and morbidity. Urinary G1 cell cycle arrest proteins TIMP-2 and IGFBP7 have recently been suggested as sensitive biomarkers for early detection of AKI in critically ill patients. However, the precise role of urinary TIMP-2 and IGFBP7 in patients undergoing TAVI is unknown. Methods: In a prospective observational trial, 40 patients undergoing TAVI (either transaortic or transapical) were enrolled. Serial measurements of TIMP-2 and IGFBP7 were performed in the early post interventional course. The primary clinical endpoint was the occurrence of AKI stage 2/3 according to the KDIGO classification. Results: Now we show, that ROC analyses of [TIMP-2]*[IGFBP7] on day one after TAVI reveals a sensitivity of 100 % and a specificity of 90 % for predicting AKI 2/3 (AUC 0.971, 95 % CI 0.914-1.0, SE 0.0299, p = 0.001, cut-off 1.03). In contrast, preoperative and postoperative serum creatinine levels as well as glomerular filtration rate (GFR) and perioperative change in GFR did not show any association with the development of AKI. Furthermore, [TIMP2]*[IGFBP7] remained stable in patients with AKI = 1, but its levels increased significantly as early as 24 h after TAVI in patients who developed AKI 2/3 in the further course (4.77 +/- 3.21 vs. 0.48 +/- 0.68, p = 0.022). Mean patients age was 81.2 +/- 5.6 years, 16 patients were male (40.0 %). 35 patients underwent transapical and five patients transaortic TAVI. 15 patients (37.5 %) developed any kind of AKI;eight patients (20 %) met the primary endpoint and seven patients required renal replacement therapy (RRT) within 72 h after surgery. Conclusion: Early elevation of urinary cell cycle arrest biomarkers after TAVI is associated with the development of postoperative AKI. [TIMP-2]*[ IGFBP7] provides an excellent diagnostic accuracy in the prediction of AKI that is superior to that of serum creatinine
Musikformulare und Presets
Prozesse des Musizierens und der Musikproduktion sind durchdrungen von formalen Vorgaben und Vor-Einstellungen (Pre-sets), die in Köpfen und Technologien gerastert und geregelt werden. Musikalische Ereignisse sind geradezu umzingelt und werden hervorgebracht durch zugrunde gelegte Formulare: Notations-, Speicher-, Wiedergabesysteme und -formate wirken als gelernte und/oder apparative Verfahren stark bestimmend. Obwohl formale Vorgaben und technologische Voreinstellungen fundamentale Wissensorganisatoren sind, verschwinden sie – manchmal buchstäblich als Masken bezeichnet – hinter irgendetwas, das nur noch als bedeutende Musiken erscheint.
Dieser Sammelband vereint kulturwissenschaftlich informierte, musikwissenschaftliche Beiträge über Musiknotation, Eurorack-Synthesizer, Musiksoftware, Blueprints für Musikgeschichte, Bedienungsanleitungen, Grooveboxen, Drum Machines, MIDI Controller, Tonträger, Band Set-ups ..
A stellar census in globular clusters with MUSE: Binaries in NGC 3201
We utilize multi-epoch MUSE spectroscopy to study binaries in the core of NGC
3201. Our sample consists of 3553 stars with 54883 spectra in total comprising
3200 main-sequence stars up to 4 magnitudes below the turn-off. Each star in
our sample has between 3 and 63 (with a median of 14) reliable radial velocity
(RV) measurements within five years of observations. We introduce a statistical
method to determine the probability of a star showing RV variations based on
the whole inhomogeneous RV sample. Using HST photometry and an advanced
dynamical MOCCA simulation of this specific GC we overcome observational biases
that previous spectroscopic studies had to deal with. This allows us to infer a
binary frequency in the MUSE FoV and enables us to deduce the underlying true
binary frequency of (6.75+-0.72) % in NGC 3201. The comparison of the MUSE
observations with the MOCCA simulation suggests a significant fraction of
primordial binaries. We can also confirm a radial increase of the binary
fraction towards the GC centre due to mass segregation. We discovered that in
our sample at least (57.5+-7.9) % of blue straggler stars (BSS) are in a binary
system. For the first time in a study of GCs, we were able to fit Keplerian
orbits to a significant sample of 95 binaries. We present the binary system
properties of eleven BSS and show evidence that two BSS formation scenarios,
the mass transfer in binary (or triple) star systems and the coalescence due to
binary-binary interactions, are present in our data. We also describe the
binary and spectroscopic properties of four sub-subgiant (or red straggler)
stars. Furthermore, we discovered two new black hole (BH) candidates with
minimum masses (Msini) of (7.68+-0.50) M_sun, (4.4+-2.8) M_sun, and refine the
minimum mass estimate on the already published BH to (4.53+-0.21) M_sun. These
BHs are consistent with an extensive BH subsystem hosted by NGC 3201
Diagnostics and correction of batch effects in large-scale proteomic studies: a tutorial.
Advancements in mass spectrometry-based proteomics have enabled experiments encompassing hundreds of samples. While these large sample sets deliver much-needed statistical power, handling them introduces technical variability known as batch effects. Here, we present a step-by-step protocol for the assessment, normalization, and batch correction of proteomic data. We review established methodologies from related fields and describe solutions specific to proteomic challenges, such as ion intensity drift and missing values in quantitative feature matrices. Finally, we compile a set of techniques that enable control of batch effect adjustment quality. We provide an R package, proBatch , containing functions required for each step of the protocol. We demonstrate the utility of this methodology on five proteomic datasets each encompassing hundreds of samples and consisting of multiple experimental designs. In conclusion, we provide guidelines and tools to make the extraction of true biological signal from large proteomic studies more robust and transparent, ultimately facilitating reliable and reproducible research in clinical proteomics and systems biology
OC5 Project Phase II: Validation of Global Loads of the DeepCwind Floating Semisubmersible Wind Turbine
This paper summarizes the findings from Phase II of the Offshore Code Comparison,
Collaboration, Continued, with Correlation project. The project is run under the
International Energy Agency Wind Research Task 30, and is focused on validating the
tools used for modeling offshore wind systems through the comparison of simulated
responses of select system designs to physical test data. Validation activities such as
these lead to improvement of offshore wind modeling tools, which will enable the
development of more innovative and cost-effective offshore wind designs. For Phase II
of the project, numerical models of the DeepCwind floating semisubmersible wind
system were validated using measurement data from a 1/50th-scale validation campaign
performed at the Maritime Research Institute Netherlands offshore wave basin.
Validation of the models was performed by comparing the calculated ultimate and
fatigue loads for eight different wave-only and combined wind/wave test cases against
the measured data, after calibration was performed using free-decay, wind-only, and
wave-only tests. The results show a decent estimation of both the ultimate and fatigue
loads for the simulated results, but with a fairly consistent underestimation in the tower
and upwind mooring line loads that can be attributed to an underestimation of waveexcitation
forces outside the linear wave-excitation region, and the presence of
broadband frequency excitation in the experimental measurements from wind.
Participant results showed varied agreement with the experimental measurements
based on the modeling approach used. Modeling attributes that enabled better
agreement included: the use of a dynamic mooring model; wave stretching, or some
other hydrodynamic modeling approach that excites frequencies outside the linear wave
region; nonlinear wave kinematics models; and unsteady aerodynamics models. Also, it
was observed that a Morison-only hydrodynamic modeling approach could create
excessive pitch excitation and resulting tower loads in some frequency bands.This work was supported by the U.S. Department of Energy under Contract No. DEAC36-
08GO28308 with the National Renewable Energy Laboratory. Some of the
funding for the work was provided by the DOE Office of Energy Efficiency and
Renewable Energy, Wind and Water Power Technologies Office
Effect of natalizumab on disease progression in secondary progressive multiple sclerosis (ASCEND). a phase 3, randomised, double-blind, placebo-controlled trial with an open-label extension
Background: Although several disease-modifying treatments are available for relapsing multiple sclerosis, treatment effects have been more modest in progressive multiple sclerosis and have been observed particularly in actively relapsing subgroups or those with lesion activity on imaging. We sought to assess whether natalizumab slows disease progression in secondary progressive multiple sclerosis, independent of relapses. Methods: ASCEND was a phase 3, randomised, double-blind, placebo-controlled trial (part 1) with an optional 2 year open-label extension (part 2). Enrolled patients aged 18–58 years were natalizumab-naive and had secondary progressive multiple sclerosis for 2 years or more, disability progression unrelated to relapses in the previous year, and Expanded Disability Status Scale (EDSS) scores of 3·0–6·5. In part 1, patients from 163 sites in 17 countries were randomly assigned (1:1) to receive 300 mg intravenous natalizumab or placebo every 4 weeks for 2 years. Patients were stratified by site and by EDSS score (3·0–5·5 vs 6·0–6·5). Patients completing part 1 could enrol in part 2, in which all patients received natalizumab every 4 weeks until the end of the study. Throughout both parts, patients and staff were masked to the treatment received in part 1. The primary outcome in part 1 was the proportion of patients with sustained disability progression, assessed by one or more of three measures: the EDSS, Timed 25-Foot Walk (T25FW), and 9-Hole Peg Test (9HPT). The primary outcome in part 2 was the incidence of adverse events and serious adverse events. Efficacy and safety analyses were done in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT01416181. Findings: Between Sept 13, 2011, and July 16, 2015, 889 patients were randomly assigned (n=440 to the natalizumab group, n=449 to the placebo group). In part 1, 195 (44%) of 439 natalizumab-treated patients and 214 (48%) of 448 placebo-treated patients had confirmed disability progression (odds ratio [OR] 0·86; 95% CI 0·66–1·13; p=0·287). No treatment effect was observed on the EDSS (OR 1·06, 95% CI 0·74–1·53; nominal p=0·753) or the T25FW (0·98, 0·74–1·30; nominal p=0·914) components of the primary outcome. However, natalizumab treatment reduced 9HPT progression (OR 0·56, 95% CI 0·40–0·80; nominal p=0·001). In part 1, 100 (22%) placebo-treated and 90 (20%) natalizumab-treated patients had serious adverse events. In part 2, 291 natalizumab-continuing patients and 274 natalizumab-naive patients received natalizumab (median follow-up 160 weeks [range 108–221]). Serious adverse events occurred in 39 (13%) patients continuing natalizumab and in 24 (9%) patients initiating natalizumab. Two deaths occurred in part 1, neither of which was considered related to study treatment. No progressive multifocal leukoencephalopathy occurred. Interpretation: Natalizumab treatment for secondary progressive multiple sclerosis did not reduce progression on the primary multicomponent disability endpoint in part 1, but it did reduce progression on its upper-limb component. Longer-term trials are needed to assess whether treatment of secondary progressive multiple sclerosis might produce benefits on additional disability components. Funding: Biogen
- …