We investigated the radio continuum spectra of 14 star-forming galaxies by fitting nonthermal (synchrotron) and thermal (free-free) radiation laws. The underlying radio continuum measurements cover a ...frequency range of ~325 MHz to 24.5 GHz (32 GHz in case of M 82). It turns out that most of these synchrotron spectra are not simple power-laws, but are best represented by a low-frequency spectrum with a mean slope αnth = 0.59 ± 0.20 (Sν ∝ ν−α), and by a break or an exponential decline in the frequency range of 1–12 GHz. Simple power-laws or mildly curved synchrotron spectra lead to unrealistically low thermal flux densities, and/or to strong deviations from the expected optically thin free-free spectra with slope αth = 0.10 in the fits. The break or cutoff energies are in the range of 1.5–7 GeV. We briefly discuss the possible origin of such a cutoff or break. If the low-frequency spectra obtained here reflect the injection spectrum of cosmic-ray electrons, they comply with the mean spectral index of Galactic supernova remnants. A comparison of the fitted thermal flux densities with the (foreground-corrected) Hα fluxes yields the extinction, which increases with metallicity. The fraction of thermal emission is higher than believed hitherto, especially at high frequencies, and is highest in the dwarf galaxies of our sample, which we interpret in terms of a lack of containment in these low-mass systems, or a time effect caused by a very young starburst.
Koopman and von Neumann (KvN) extended the Liouville equation by introducing a phase space function
S
(
K
)
(
q
,
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,
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whose physical meaning is unknown. We show that a different
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,
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derivation
of quantum operators and evolution equations from corresponding classical entities. It is performed by replacing
∂
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by 0 and
p
by
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∂
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, thus providing an explanation for the common quantization rules.
High-throughput DNA sequencing significantly contributed to diagnosis and prognostication in patients with myelodysplastic syndromes (MDS). We determined the biological and prognostic significance of ...genetic aberrations in MDS. In total, 944 patients with various MDS subtypes were screened for known/putative mutations/deletions in 104 genes using targeted deep sequencing and array-based genomic hybridization. In total, 845/944 patients (89.5%) harbored at least one mutation (median, 3 per patient; range, 0-12). Forty-seven genes were significantly mutated with TET2, SF3B1, ASXL1, SRSF2, DNMT3A, and RUNX1 mutated in >10% of cases. Many mutations were associated with higher risk groups and/or blast elevation. Survival was investigated in 875 patients. By univariate analysis, 25/48 genes (resulting from 47 genes tested significantly plus PRPF8) affected survival (P<0.05). The status of 14 genes combined with conventional factors revealed a novel prognostic model ('Model-1') separating patients into four risk groups ('low', 'intermediate', 'high', 'very high risk') with 3-year survival of 95.2, 69.3, 32.8, and 5.3% (P<0.001). Subsequently, a 'gene-only model' ('Model-2') was constructed based on 14 genes also yielding four significant risk groups (P<0.001). Both models were reproducible in the validation cohort (n=175 patients; P<0.001 each). Thus, large-scale genetic and molecular profiling of multiple target genes is invaluable for subclassification and prognostication in MDS patients.
We show that quantum theory (QT) is a substructure of classical probabilistic physics. The central quantity of the classical theory is Hamilton’s function, which determines canonical equations, a ...corresponding flow, and a Liouville equation for a probability density. We extend this theory in two respects: (1) The same structure is defined for arbitrary observables. Thus, we have all of the above entities generated not only by Hamilton’s function but also by every observable. (2) We introduce for each observable a phase space function representing the classical action. This is a redundant quantity in a classical context but indispensable for the transition to QT. The basic equations of the resulting theory take a “quantum-like” form, which allows for a simple derivation of QT by means of a projection to configuration space reported previously Quantum Stud Math Found 5:219–227, 2018. We obtain the most important relations of QT, namely the form of operators, Schrödinger’s equation, eigenvalue equations, commutation relations, expectation values, and Born’s rule. Implications for the interpretation of QT are discussed, as well as an alternative projection method allowing for a derivation of spin.
Global Monitoring for Environment and Security (GMES) is the European programme to establish a European capacity for Earth Observation. GMES is designed to provide European policy makers and public ...authorities with accurate and timely information to better manage the environment, understand and mitigate the effects of climate change and ensure civil security. Sentinel-3 is an Earth observation satellite mission specifically designed for GMES to ensure the long-term collection and operational delivery of high-quality measurements to GMES ocean, land, and atmospheric services, while contributing to the GMES, emergency and security services. Key Sentinel-3 measurement requirements, corresponding to identified GMES user needs, have been derived as follows:•Sea surface topography (SSH), significant wave height (Hs) and surface wind speed derived over the global ocean to an equivalent accuracy and precision as that presently achieved by ENVISAT Radar Altimeter-2 (RA-2) but with enhanced surface topography measurements in the coastal zone, sea ice regions and over inland rivers, their tributaries and lakes.•Sea surface temperature (SST) determined for oceanic and coastal waters globally to an equivalent accuracy and precision as that presently achieved by the ENVISAT Advanced Along Track Scanning Radiometer (AATSR) over the ocean (i.e. <0.3K), at a spatial resolution of 1km.•Visible, and Short-Wave Infrared radiances for oceanic, inland and coastal waters at a spatial resolution of 0.3km (simultaneously and co-registered with SST measurements), determined to an equivalent level of accuracy and precision as ENVISAT Medium Resolution Imaging Spectrometer with complete ocean coverage in 2–3days.•Visible and infrared radiances over global land-surfaces in 1–2days, sea-ice and ice-sheets equivalent to those currently provided from ENVISAT MERIS, AATSR and Système Probatoire d'Observation de la Terre (SPOT) Vegetation.
The Sentinel-3 mission addresses these requirements by implementing and operating:•A dual frequency, Synthetic Aperture Radar Altimeter (SRAL) instrument supported by a dual frequency passive microwave radiometer (MWR) for wet-tropospheric correction, a Precise Orbit Determination package including a GPS receiver, a DORIS instrument and a laser retro-reflector.•A highly sensitive Ocean and Land Colour Imager (OLCI) delivering multi-channel wide-swath optical measurements for ocean and land surfaces.•A dual-view Sea and Land Surface Temperature Radiometer (SLSTR) delivering accurate surface ocean, land, and ice temperature.•A collaborative ground segment providing management of the mission, management, development, production and access to core data products in an operational near real time delivery context.
The mission foresees a series of satellites, each having 7-year lifetime, over a 20-year period starting with the launch of Sentinel-3A in late 2013 and of Sentinel-3B in late 2014. During full operations two identical satellites will be maintained in the same orbit with a phase delay of 180°.
This paper provides an overview of the GMES Sentinel-3 mission including the mission background and user requirements, a technical description of the space segment, a brief overview of the ground segment concept, and a summary description of Sentinel-3 data products and their anticipated performance.
► A new satellite mission called Sentinel-3 dedicated to oceanography is described. ► A technical overview of the Sentinel-3 instrument payload is presented. ► A summary of the Sentinel-3 ground segment and operations concept is presented. ► A summary of products derived from Sentinel-3 payload instruments is presented.
Abstract
We have performed 323 MHz observations with the Giant Metrewave Radio Telescope of the most promising candidates selected from the MACS catalogue. The aim of the work is to extend our ...knowledge of the radio halo and relic populations to z > 0.3, the epoch in which massive clusters are formed. In MACSJ1149.5+2223 and MACSJ1752.1+4440, we discovered two double-relic systems with a radio halo, and in MACSJ0553.4−3342 we found a radio halo. Archival Very Large Array observations and Westerbork Synthesis Radio Telescope observations have been used to study the polarization and spectral-index properties. The radio halo in MACSJ1149.5+2223 has the steepest spectrum ever found so far in these objects (α ≥ 2). The double relics in MACSJ1149.5+2223 are peculiar in their position that is misaligned with the main merger axis. The relics are polarized up to 30 and 40 per cent in MACSJ1149.5+2223 and MACSJ1752.040+44, respectively. In both cases, the magnetic field is roughly aligned with the relics' main axes. The spectra in the relics in MACSJ1752.040+44 steepen towards the cluster centre, in agreement with model expectations. X-ray data on MACSJ0553.4−3342 suggest that this cluster is undergoing a major merger, with the merger axis close to the plane of the sky. The cores of the disrupted clusters have just passed each other, but no radio relic is detected in this system. If turbulence is responsible for the radio emission, we argue that it must develop before the core passage. A comparison of double-relic plus halo system with cosmological simulations allows a simultaneous estimate of the acceleration efficiencies at shocks (to produce relics) and of turbulence (to produce the halo).
The benefit of implantable cardioverter-defibrillator (ICD) therapy depends upon appropriate evaluation of a persisting risk of sudden death and estimation of the patient's overall survival. ...Assessment of a stable and unchangeable arrhythmogenic substrate is often difficult. Structural abnormality and ventricular dysfunction, the two major risk parameters, may recover, and heart failure symptoms can improve so that ICD therapy may not be indicated. Risk stratification can take time while the patient continues to be at high risk of arrhythmic death, and patients may need temporary bridging by a defibrillator in cases of interrupted ICD therapy. The wearable cardioverter-defibrillator (WCD) combines a long-term electrocardiogram (ECG)-monitoring system with an external automatic defibrillator. The LIfeVest® (ZOLL, Pittsburgh, PA, USA) is composed of a garment, containing two defibrillation patch electrodes on the back, and an elastic belt with a front-defibrillation patch electrode and four non-adhesive ECG electrodes, connected to a monitoring and defibrillation unit. The WCD is a safe and effective tool to terminate ventricular tachycardia/ventricular fibrillation events, unless a conscious patient withholds shock delivery. It may be used in patients in the early phase after acute myocardial infarction with poor left ventricular function, after acute coronary revascularization procedures (percutaneous coronary intervention or coronary artery bypass grafting) and reduced left ventricular ejection fraction (≤35%), in patients with acute heart failure in non-ischaemic cardiomyopathy of uncertain aetiology and prognosis. The WCD may be helpful in subjects with syncope of assumed tachyarrhythmia origin or in patients with inherited arrhythmia syndromes. The WCD may replace ICD implantation in patients waiting for heart transplantation or who need a ventricular-assist device. This review describes the technical details and characteristics of the WCD, discusses its various potential applications, and reports the currently available experience with the wearable defibrillator.
In the current ΛCDM cosmological scenario, N-body simulations provide us with a universal mass profile, and consequently a universal equilibrium circular velocity of the virialized objects, as ...galaxies. In this paper we obtain, by combining kinematical data of their inner regions with global observational properties, the universal rotation curve of disc galaxies and the corresponding mass distribution out to their virial radius. This curve extends the results of Paper I, concerning the inner luminous regions of Sb–Im spirals, out to the edge of the galaxy haloes.
An important determinant of successful cardiac resynchronization therapy for heart failure is the position of the left ventricular (LV) pacing lead. The aim of this study was to analyze the impact of ...the LV lead position on outcome in patients randomized to cardiac resynchronization-defibrillation in the Multicenter Automatic Defibrillator Implantation Trial-Cardiac Resynchronization Therapy (MADIT-CRT) study.
The location of the LV lead was assessed by means of coronary venograms and chest x-rays recorded at the time of device implantation. The LV lead location was classified along the short axis into an anterior, lateral, or posterior position and along the long axis into a basal, midventricular, or apical region. The primary end point of MADIT-CRT was heart failure (HF) hospitalization or death, whichever came first. The LV lead position was assessed in 799 patients, (55% patients ≥65 years of age, 26% female, 10% LV ejection fraction ≤25%, 55% ischemic cardiomyopathy, and 71% left bundle-branch block) with a follow-up of 29±11 months. The extent of cardiac resynchronization therapy benefit was similar for leads in the anterior, lateral, or posterior position (P=0.652). The apical lead location compared with leads located in the nonapical position (basal or midventricular region) was associated with a significantly increased risk for heart failure/death (hazard ratio=1.72; 95% confidence interval, 1.09 to 2.71; P=0.019) after adjustment for the clinical covariates. The apical lead position was also associated with an increased risk for death (hazard ratio=2.91; 95% confidence interval, 1.42 to 5.97; P=0.004).
LV leads positioned in the apical region were associated with an unfavorable outcome, suggesting that this lead location should be avoided in cardiac resynchronization therapy. Clinical Trial Registration- URL: http://clinicaltrials.gov. Unique identifier: NCT00180271.
Context. Radio relics are extended synchrotron sources thought to be produced by shocks in the outskirts of merging galaxy clusters. The cluster Abell 2256 hosts one of the most intriguing examples ...in this class of sources. It has been found that this radio relic has a rather flat integrated spectrum at low frequencies that would imply an injection spectral index for the electrons that is inconsistent with the flattest allowed by the test particle diffusive shock acceleration (DSA). Aims. We aim at testing the origins of the radio relic in Abell 2256. Methods. We performed new high-frequency observations at 2273, 2640, and 4850 MHz. Combining these new observations with images available in the literature, we constrain the radio-integrated spectrum of the radio relic in Abell 2256 over the widest sampled frequency range collected so far for this class of objects (63−10 450 MHz). Moreover, we used X-ray observations of the cluster to check the temperature structure in the regions around the radio relic. Results. We find that the relic keeps an unusually flat behavior up to high frequencies. Although the relic integrated spectrum between 63 and 10 450 MHz is not inconsistent with a single power law with α6310 450 = 0.92 ± 0.02, we find hints of a steepening at frequencies >1400 MHz. The two frequency ranges 63−1369 MHz and 1369−10 450 MHz are, indeed, best represented by two different power laws, with α631369 = 0.85 ± 0.01 and α136910 450 = 1.00 ± 0.02. This broken power law would require special conditions to be explained in terms of test-particle DSA, e.g., non-stationarity of the spectrum, which would make the relic in A2256 a rather young system, and/or non-stationarity of the shock. On the other hand, the single power law would make of this relic the one with the flattest integrated spectrum known so far, even flatter than what is allowed in the test-particle approach to DSA. We find a rather low temperature ratio of T2/T1 ~ 1.7 across the G region of the radio relic and no temperature jump across the H region. However, in both regions projection effects might have affected the measurements, thereby reducing the contrast.
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