The Asteroid Terrestrial-impact Last Alert System (ATLAS) observes most of the sky every night in search of dangerous asteroids. Its data are also used to search for photometric variability, where ...sensitivity to variability is limited by photometric accuracy. Since each exposure spans 7 6 corner to corner, variations in atmospheric transparency in excess of 0.01 mag are common, and 0.01 mag photometry cannot be achieved by using a constant flat-field calibration image. We therefore have assembled an all-sky reference catalog of approximately one billion stars to m ∼ 19 from a variety of sources to calibrate each exposure's astrometry and photometry. Gaia DR2 is the source of astrometry for this ATLAS Refcat2. The sources of g, r, i, and z photometry include Pan-STARRS DR1, the ATLAS Pathfinder photometry project, ATLAS reflattened APASS data, SkyMapper DR1, APASS DR9, the Tycho-2 catalog, and the Yale Bright Star Catalog. We have attempted to make this catalog at least 99% complete to m < 19, including the brightest stars in the sky. We believe that the systematic errors are no larger than 5 mmag rms, although errors are as large as 20 mmag in small patches near the Galactic plane.
The Asteroid Terrestrial impact Last Alert System (ATLAS) system consists of two 0.5 m Schmidt telescopes with cameras covering 29 square degrees at plate scale of 1.86 arcsec per pixel. Working in ...tandem, the telescopes routinely survey the whole sky visible from Hawaii (above δ > − 50 ° ) every two nights, exposing four times per night, typically reaching o < 19 magnitude per exposure when the moon is illuminated and c < 19.5 magnitude per exposure in dark skies. Construction is underway of two further units to be sited in Chile and South Africa which will result in an all-sky daily cadence from 2021. Initially designed for detecting potentially hazardous near earth objects, the ATLAS data enable a range of astrophysical time domain science. To extract transients from the data stream requires a computing system to process the data, assimilate detections in time and space and associate them with known astrophysical sources. Here we describe the hardware and software infrastructure to produce a stream of clean, real, astrophysical transients in real time. This involves machine learning and boosted decision tree algorithms to identify extragalactic and Galactic transients. Typically we detect 10-15 supernova candidates per night which we immediately announce publicly. The ATLAS discoveries not only enable rapid follow-up of interesting sources but will provide complete statistical samples within the local volume of 100 Mpc. A simple comparison of the detected supernova rate within 100 Mpc, with no corrections for completeness, is already significantly higher (factor 1.5 to 2) than the current accepted rates.
ATLAS: A High-cadence All-sky Survey System Tonry, J. L.; Denneau, L.; Heinze, A. N. ...
Publications of the Astronomical Society of the Pacific,
06/2018, Letnik:
130, Številka:
988
Journal Article
Recenzirano
Odprti dostop
Technology has advanced to the point that it is possible to image the entire sky every night and process the data in real time. The sky is hardly static: many interesting phenomena occur, including ...variable stationary objects such as stars or QSOs, transient stationary objects such as supernovae or M dwarf flares, and moving objects such as asteroids and the stars themselves. Funded by NASA, we have designed and built a sky survey system for the purpose of finding dangerous near-Earth asteroids (NEAs). This system, the "Asteroid Terrestrial-impact Last Alert System" (ATLAS), has been optimized to produce the best survey capability per unit cost, and therefore is an efficient and competitive system for finding potentially hazardous asteroids (PHAs) but also for tracking variables and finding transients. While carrying out its NASA mission, ATLAS now discovers more bright (m < 19) supernovae candidates than any ground based survey, frequently detecting very young explosions due to its 2 day cadence. ATLAS discovered the afterglow of a gamma-ray burst independent of the high energy trigger and has released a variable star catalog of 5 × 106 sources. This is the first of a series of articles describing ATLAS, devoted to the design and performance of the ATLAS system. Subsequent articles will describe in more detail the software, the survey strategy, ATLAS-derived NEA population statistics, transient detections, and the first data release of variable stars and transient light curves.
Background
The healthcare sector is responsible for 4%–10% of global greenhouse gas emissions. Considering the broad range of care that obstetricians and gynaecologists provide, mitigation strategies ...within this specialty could result in significant reductions of the environmental footprint across the whole healthcare industry.
Objectives
The aim of this review was to identify for what services, procedures and products within obstetric and gynaecological care the environmental impact has been studied, to assess the magnitude of such impact and to identify mitigation strategies to diminish it.
Search strategy
The search strategy combined terms related to environmental impact, sustainability, climate change or carbon footprint, with the field of obstetrics and gynaecology.
Selection criteria
Articles reporting on the environmental impact of any service, procedure or product within the field of obstetrics and gynaecology were included. Included outcomes covered midpoint impact categories, CO2 emissions, waste generation and energy consumption.
Data collection and analysis
A systematic literature search was conducted in the databases of MEDLINE (Ovid), Embase (Ovid) and Scopus, and a grey literature search was performed on Google Scholar and two websites of gynaecological associations.
Main results
The scope of the investigated studies encompassed vaginal births, obstetric and gynaecological surgical procedures, menstrual products, vaginal specula and transportation to gynaecological oncologic consultations. Among the highest yielding mitigation strategies were displacing disposable with reusable materials and minimising content of surgical custom packs. The lowest yielding mitigation strategy was waste optimisation, including recycling.
Conclusions
This systematic review highlights opportunities for obstetricians and gynaecologists to decrease their environmental footprint in many ways. More high‐quality studies are needed to investigate the environmental impact of other aspects of women's and reproductive health care.
ABSTRACT
We present here the discovery of a new class of superslow rotating asteroids (Prot ≳1000 h) in data extracted from the Asteroid Terrestrial-impact Last Alert System (ATLAS) and Zwicky ...Transient Facility (ZTF) all-sky surveys. Of the 39 rotation periods we report here, 32 have periods longer than any previously reported unambiguous rotation periods currently in the Asteroid Light Curve Data base. In our sample, seven objects have a rotation period >4000 h and the longest period we report here is 4812 h (∼200 d). We do not observe any correlation between taxonomy, albedo, or orbital properties with superslow rotating status. The most plausible mechanism for the creation of these very slow rotators is if their rotations were slowed by YORP spin-down. Superslow rotating asteroids may be common, with at least 0.4 per cent of the main-belt asteroid population with a size range between 2 and 20 km in diameter rotating with periods longer than 1000 h.
Lack of suitable in vitro culture conditions for primary acute lymphoblastic leukaemia (ALL) cells severely impairs their experimental accessibility and the testing of new drugs on cell material ...reflecting clonal heterogeneity in patients. We show that Nestin-positive human mesenchymal stem cells (MSCs) support expansion of a range of biologically and clinically distinct patient-derived ALL samples. Adherent ALL cells showed an increased accumulation in the S phase of the cell cycle and diminished apoptosis when compared with cells in the suspension fraction. Moreover, surface expression of adhesion molecules CD34, CDH2 and CD10 increased several fold. Approximately 20% of the ALL cells were in G0 phase of the cell cycle, suggesting that MSCs may support quiescent ALL cells. Cellular barcoding demonstrated long-term preservation of clonal abundance. Expansion of ALL cells for >3 months compromised neither feeder dependence nor cancer initiating ability as judged by their engraftment potential in immunocompromised mice. Finally, we demonstrate the suitability of this co-culture approach for the investigation of drug combinations with luciferase-expressing primograft ALL cells. Taken together, we have developed a preclinical platform with patient-derived material that will facilitate the development of clinically effective combination therapies for ALL.
Diffusion weighted imaging (DWI) is the most important sequence for detection and grading prostate cancer (PCa), but it is considerably prone to artifacts. New approaches like zoomed single-shot ...imaging (z-EPI) with advanced image processing or multi-shot readout segmentation (rs-EPI) try to improve DWI quality. This study evaluates objective and subjective image quality (IQ) of rs-EPI and z-EPI with and without advanced processing.
Fifty-six consecutive patients (67 ± 8 years; median PSA 8.3 ng/ml) with mp-MRI performed at 3 Tesla between February and October 2019 and subsequently verified PCa by targeted plus systematic MRI/US-fusion biopsy were included in this retrospective single center cohort study. Rs-EPI and z-EPI were prospectively acquired in every patient. Signal intensities (SI) of PCa and benign tissue in ADC, b1000, and calculated high b-value images were analyzed. Endpoints were signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), PCa contrast intensity (CI), and subjective IQ on a 5-point scale evaluated by three blinded readers. Wilcoxon signed rank test, Friedman test and Cohen's kappa coefficient was calculated.
SNR, CNR, and PCa CI of z-EPI with and without advanced processing was superior to rs-EPI (p < 0.01), whereas no significant differences were observed between z-EPI with and without advanced processing. Subjective IQ was significantly higher for z-EPI with advanced processing compared rs-EPI for ADC, b1000, and calculated high b-values (p < 0.01). Compared to z-EPI without advanced processing, z-EPI with advanced processing was superior for ADC and calculated high b-values (p < 0.01), but no significant differences were shown for b1000 images.
Z-EPI with and without advanced processing was superior to rs-EPI regarding objective imaging parameters and z-EPI with advanced processing was superior to rs-EPI regarding subjective imaging parameters for the detection of PCa.
Abstract
In Smith et al. we published estimates of the volumetric rate of supernovae within 100 Mpc. These were incorrect and we present the correct values in this corrigendum.
Plant‐pathogenic fungi are causative agents of the majority of plant diseases and can lead to severe crop loss in infected populations. Fungal colonization is achieved by combining different ...strategies, such as avoiding and counteracting the plant immune system and manipulating the host metabolome. Of major importance are virulence factors secreted by fungi, which fulfil diverse functions to support the infection process. Most of these proteins are highly specialized, with structural and biochemical information often absent. Here, we present the atomic structures of the cerato‐platanin‐like protein Cpl1 from Ustilago maydis and its homologue Uvi2 from Ustilago hordei. Both proteins adopt a double‐Ψβ‐barrel architecture reminiscent of cerato‐platanin proteins, a class so far not described in smut fungi. Our structure–function analysis shows that Cpl1 binds to soluble chitin fragments via two extended grooves at the dimer interface of the two monomer molecules. This carbohydrate‐binding mode has not been observed previously and expands the repertoire of chitin‐binding proteins. Cpl1 localizes to the cell wall of U. maydis and might synergize with cell wall‐degrading and decorating proteins during maize infection. The architecture of Cpl1 harbouring four surface‐exposed loop regions supports the idea that it might play a role in the spatial coordination of these proteins. While deletion of cpl1 has only mild effects on the virulence of U. maydis, a recent study showed that deletion of uvi2 strongly impairs U. hordei virulence. Our structural comparison between Cpl1 and Uvi2 reveals sequence variations in the loop regions that might explain a diverging function.
Our structure–function analysis of the CP‐like protein 1 (Cpl1) from Ustilago maydis revealed a new mode of chitin binding and suggests synergy with other secreted fungal proteins during infection.
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