We present the Lambda Adaptive Multi-Band Deblending Algorithm in R (lambdar), a novel code for calculating matched aperture photometry across images that are neither pixel- nor PSF-matched, using ...prior aperture definitions derived from high-resolution optical imaging. The development of this program is motivated by the desire for consistent photometry and uncertainties across large ranges of photometric imaging, for use in calculating spectral energy distributions. We describe the program, specifically key features required for robust determination of panchromatic photometry: propagation of apertures to images with arbitrary resolution, local background estimation, aperture normalization, uncertainty determination and propagation, and object deblending. Using simulated images, we demonstrate that the program is able to recover accurate photometric measurements in both high-resolution, low-confusion, and low-resolution, high-confusion, regimes. We apply the program to the 21-band photometric data set from the Galaxy And Mass Assembly (GAMA) Panchromatic Data Release (PDR; Driver et al. 2016), which contains imaging spanning the far-UV to the far-IR. We compare photometry derived from lambdar with that presented in Driver et al. (2016), finding broad agreement between the data sets. None the less, we demonstrate that the photometry from lambdar is superior to that from the GAMA PDR, as determined by a reduction in the outlier rate and intrinsic scatter of colours in the lambdar data set. We similarly find a decrease in the outlier rate of stellar masses and star formation rates using lambdar photometry. Finally, we note an exceptional increase in the number of UV and mid-IR sources able to be constrained, which is accompanied by a significant increase in the mid-IR colour–colour parameter-space able to be explored.
Electrical switching of an antiferromagnet Wadley, P.; Howells, B.; Železný, J. ...
Science (American Association for the Advancement of Science),
02/2016, Letnik:
351, Številka:
6273
Journal Article
Recenzirano
Odprti dostop
Antiferromagnets are hard to control by external magnetic fields because of the alternating directions of magnetic moments on individual atoms and the resulting zero net magnetization. However, ...relativistic quantum mechanics allows for generating current-induced internal fields whose sign alternates with the periodicity of the antiferromagnetic lattice. Using these fields, which couple strongly to the antiferromagnetic order, we demonstrate room-temperature electrical switching between stable configurations in antiferromagnetic CuMnAs thin-film devices by applied current with magnitudes of order 10⁶ ampere per square centimeter. Electrical writing is combined in our solid-state memory with electrical readout and the stored magnetic state is insensitive to and produces no external magnetic field perturbations, which illustrates the unique merits of antiferromagnets for spintronics.
We present Atacama Large Millimeter Array 850 m continuum observations of the Orion Nebula Cluster that provide the highest angular resolution (∼0 1 40 au) and deepest sensitivity (∼0.1 mJy) of the ...region to date. We mosaicked a field containing ∼225 optical or near-IR-identified young stars, ∼60 of which are also optically identified "proplyds." We detect continuum emission at 850 m toward ∼80% of the proplyd sample, and ∼50% of the larger sample of previously identified cluster members. Detected objects have fluxes of ∼0.5-80 mJy. We remove submillimeter flux due to free-free emission in some objects, leaving a sample of sources detected in dust emission. Under standard assumptions of isothermal, optically thin disks, submillimeter fluxes correspond to dust masses of ∼0.5-80 Earth masses. We measure the distribution of disk sizes, and find that disks in this region are particularly compact. Such compact disks are likely to be significantly optically thick. The distributions of submillimeter flux and inferred disk size indicate smaller, lower-flux disks than in lower-density star-forming regions of similar age. Measured disk flux is correlated weakly with stellar mass, contrary to studies in other star-forming regions that found steeper correlations. We find a correlation between disk flux and distance from the massive star θ1 Ori C, suggesting that disk properties in this region are influenced strongly by the rich cluster environment.
Accurately accounting for new particle formation (NPF) is crucial to our ability to predict aerosol number concentrations in many environments and thus cloud properties, which is in turn vital in ...simulating radiative transfer and climate. Here we present an analysis of NPF events observed in the Greenland Sea during the summertime as part of the Aerosol-Cloud Coupling And Climate Interactions in the Arctic (ACCACIA) project. While NPF events have been reported in the Arctic before, we were able, for the first time, to detect iodine in the growing particles using an Aerosol Mass Spectrometer (AMS) during a persistent event in the region of the coastal sea-ice near Greenland. Given the potency of iodine as a nucleation precursor, the results imply that iodine was responsible for the initial NPF, a phenomenon that has been reported at lower latitudes and associated with molecular iodine emissions from coastal macroalgae. The initial source of iodine in this instance is not clear, but it was associated with air originating approximately 1 day previously over melting coastal sea-ice. These results show that atmospheric models must consider iodine as a source of new particles in addition to established precursors such as sulfur compounds.
Summary
Background
Crohn's disease recurs in the majority of patients after intestinal resection.
Aim
To compare the relative efficacy of thiopurines and anti‐TNF therapy in patients at high risk of ...disease recurrence.
Methods
As part of a larger study comparing post‐operative management strategies, patients at high risk of recurrence (smoker, perforating disease, ≥2nd operation) were treated after resection of all macroscopic disease with 3 months metronidazole together with either azathioprine 2 mg/kg/day or mercaptopurine 1.5 mg/kg/day. Thiopurine‐intolerant patients received adalimumab induction then 40 mg fortnightly. Patients underwent colonoscopy at 6 months with endoscopic recurrence assessed blind to treatment.
Results
A total of 101 patients 50% male; median (IQR) age 36 (25–46) years were included. There were no differences in disease history between thiopurine‐ and adalimumab‐treated patients. Fifteen patients withdrew prior to 6 months, five due to symptom recurrence (of whom four were colonoscoped). Endoscopic recurrence (Rutgeerts score i2–i4) occurred in 33 of 73 (45%) thiopurine vs. 6 of 28 (21%) adalimumab‐treated patients intention‐to‐treat (ITT); P = 0.028 or 24 of 62 (39%) vs. 3 of 24 (13%) respectively per‐protocol analysis (PPA); P = 0.020. Complete mucosal endoscopic normality (Rutgeerts i0) occurred in 17/73 (23%) vs. 15/28 (54%) (ITT; P = 0.003) and in 27% vs. 63% (PPA; P = 0.002). The most advanced disease (Rutgeerts i3 and i4) occurred in 8% vs. 4% (thiopurine vs. adalimumab).
Conclusions
In Crohn's disease patients at high risk of post‐operative recurrence adalimumab is superior to thiopurines in preventing early disease recurrence.
Forests fires are a significant source of chemicals to the atmosphere including numerous non-methane organic compounds (NMOCs). We report airborne measurement of hydrocarbons, acetone and methanol ...from >500 whole air samples collected over Eastern Canada, including interceptions of several different boreal biomass burning plumes. From these and concurrent measurements of carbon monoxide (CO) we derive fire emission ratios for 29 different organic species relative to the emission of CO. These range from 8.9 ± 3.2 ppt ppb−1 CO for methanol to 0.007 ± 0.004 ppt ppb−1 CO for cyclopentane. The ratios are in good to excellent agreement with literature values. Using the GEOS-Chem global 3-D chemical transport model (CTM) we show the influence of biomass burning on the global distributions of benzene, toluene, ethene and propene (species which are controlled for air quality purposes and sometimes used as indicative tracers of anthropogenic activity). Using our observationally derived emission ratios and the GEOS-Chem CTM, we show that biomass burning can be the largest fractional contributor to observed benzene, toluene, ethene and propene levels in many global locations. The widespread biomass burning contribution to atmospheric benzene, a heavily regulated air pollutant, suggests that pragmatic approaches are needed when setting air quality targets as tailpipe and solvent emissions decline in developed countries. We subsequently determine the extent to which the 28 global-status World Meteorological Organisation – Global Atmosphere Watch stations worldwide are influenced by biomass burning sourced benzene, toluene, ethene and propene as compared to their exposure to anthropogenic emissions.
APOGEE-2 is a high-resolution, near-infrared spectroscopic survey observing ∼3 × 105 stars across the entire sky. It is the successor to APOGEE and is part of the Sloan Digital Sky Survey IV ...(SDSS-IV). APOGEE-2 is expanding on APOGEE's goals of addressing critical questions of stellar astrophysics, stellar populations, and Galactic chemodynamical evolution using (1) an enhanced set of target types and (2) a second spectrograph at Las Campanas Observatory in Chile. APOGEE-2 is targeting red giant branch and red clump stars, RR Lyrae, low-mass dwarf stars, young stellar objects, and numerous other Milky Way and Local Group sources across the entire sky from both hemispheres. In this paper, we describe the APOGEE-2 observational design, target selection catalogs and algorithms, and the targeting-related documentation included in the SDSS data releases.
Brain inflammation is a double-edged sword. It is required for brain repair in acute damage, whereas chronic inflammation and autoimmune disorders are neuropathogenic. Certain proinflammatory ...cytokines and chemokines are closely related to cognitive dysfunction and neurodegeneration. Representative anti-inflammatory cytokines, such as interleukin (IL)-10, can suppress neuroinflammation and have significant therapeutic potentials in ameliorating neurodegenerative disorders such as Alzheimer's disease (AD). Here, we show that adeno-associated virus (AAV) serotype 2/1 hybrid-mediated neuronal expression of the mouse IL-10 gene ameliorates cognitive dysfunction in amyloid precursor protein+ presenilin-1 bigenic mice. AAV2/1 infection of hippocampal neurons resulted in sustained expression of IL-10 without its leakage into the blood, reduced astro/microgliosis, enhanced plasma amyloid-β peptide (Aβ) levels and enhanced neurogenesis. Moreover, increased levels of IL-10 improved spatial learning, as determined by the radial arm water maze. Finally, IL-10-stimulated microglia enhanced proliferation but not differentiation of primary neural stem cells in the co-culture system, whereas IL-10 itself had no effect. Our data suggest that IL-10 gene delivery has a therapeutic potential for a non-Aβ-targeted treatment of AD.
Third-harmonic scattering is a nonlinear optical process that involves the molecular second-hyperpolarizability, γ. This work presents a rigorous quantum electrodynamical analysis of the scattering ...process, involving a partially index-symmetric construction of the fourth-rank γ tensordispensing with the Kleinman symmetry condition. To account for stochastic molecular rotation in fluids, methods of isotropic averaging must be employed to relate the molecular properties to accessible experimental quantities such as depolarization ratio. A complete eighth-rank tensor rotational average yields results for observable third-harmonic scattering rates, cast as a function of the natural-invariant γ components, and the polarization geometry of the experiment. Decomposing the tensor γ into irreducible weights allows specific predictions to be made for each molecular point group, allowing greater discrimination between the results for different molecular symmetries.
The surface and subsurface of comets preserve material from the formation of the solar system. The properties of cometary material thus provide insight into the physical and chemical conditions ...during their formation. We present mass spectra taken by the Ptolemy instrument 20 minutes after the initial touchdown of the Philae lander on the surface of comet 67P/Churyumov-Gerasimenko. Regular mass distributions indicate the presence of a sequence of compounds with additional -CH2- and -O- groups (mass/charge ratios 14 and 16, respectively). Similarities with the detected coma species of comet Halley suggest the presence of a radiation-induced polymer at the surface. Ptolemy measurements also indicate an apparent absence of aromatic compounds such as benzene, a lack of sulfur-bearing species, and very low concentrations of nitrogenous material.
PDF
