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The Rapid ASKAP Continuum Survey (RACS) is the first large-area survey to be conducted with the full 36-antenna Australian Square Kilometre Array Pathfinder (ASKAP) telescope. RACS will provide a shallow model of the ASKAP sky that will aid the calibration of future deep ASKAP surveys. RACS will cover the whole sky visible from the ASKAP site in Western Australia and will cover the full ASKAP band of 700–1800 MHz. The RACS images are generally deeper than the existing NRAO VLA Sky Survey and Sydney University Molonglo Sky Survey radio surveys and have better spatial resolution. All RACS survey products will be public, including radio images (with
15 arcsec resolution) and catalogues of about three million source components with spectral index and polarisation information. In this paper, we present a description of the RACS survey and the first data release of 903 images covering the sky south of declination
made over a 288-MHz band centred at 887.5 MHz.
Recently, several incidents of glyphosate failure on junglerice [Echinochloa colona (L.) Link] have been reported in the midsouthern United States, specifically in Mississippi and Tennessee. Research was conducted to measure the magnitude of glyphosate resistance and to determine the mechanism(s) of resistance to glyphosate in E. colona populations from Mississippi and Tennessee. ED50 (dose required to reduce plant growth by 50%) values for a resistant MSGR4 biotype, a resistant TNGR population, and a known susceptible MSGS population were 0.8, 1.62, and 0.23 kg ae ha−1 of glyphosate, respectively. The resistance index calculated from the these ED50 values indicated that the MSGR4 biotype and TNGR population were 4- and 7-fold, respectively, resistant to glyphosate relative to the MSGS population. The absorption patterns of [14C]glyphosate in the TNGR and MSGS populations were similar. However, the MSGS population translocated 13% more [14C]glyphosate out of the treated leaf compared with the TNGR population at 48 h after treatment. EPSPS gene sequence analyses of TNGR E. colona indicated no evidence of any point mutations, but several resistant biotypes, including MSGR4, possessed a single-nucleotide substitution of T for C at codon 106 position, resulting in a proline-to-serine substitution (CCA to TCA). Results from quantitative polymerase chain reaction analyses suggested that there was no amplification of the EPSPS gene in the resistant populations and biotypes. Thus, the mechanism of resistance in the MSGR population (and associated biotypes) is, in part, due to a target-site mutation at the 106 loci of the EPSPS gene, while reduced translocation of glyphosate was found to confer glyphosate resistance in the TNGR population.
Although interstage mortality for infants with hypoplastic left heart syndrome has declined within the National Pediatric Cardiology Quality Improvement Collaborative, variation across centres persists. It remains unclear whether centres with lower interstage mortality have lower-risk patients or whether differences in care may explain this variation. We examined previously established risk factors across National Pediatric Cardiology Quality Improvement Collaborative centres with lower and higher interstage mortality rates.
Lower-mortality centres were defined as those with >25 consecutive interstage survivors. Higher-mortality centres were defined as those with cumulative interstage mortality rates >10%, which is a collaborative historic baseline rate. Baseline risk factors and perioperative characteristics were compared.
Seven lower-mortality centres were identified (n=331 patients) and had an interstage mortality rate of 2.7%, as compared with 13.3% in the four higher-mortality centres (n=173 patients, p<0.0001). Of all baseline risk factors examined, the only factor that differed between the lower- and higher-mortality centres was postnatal diagnosis (18.4 versus 31.8%, p=0.001). In multivariable analysis, there remained a significant mortality difference between the two groups of centres after adjusting for this variable: adjusted mortality rate was 2.8% in lower-mortality centres compared with 12.6% in higher-mortality centres, p=0.003. Secondary analyses identified multiple differences between groups in perioperative practices and other variables.
Variation in interstage mortality rates between these two groups of centres does not appear to be explained by differences in baseline risk factors. Further study is necessary to evaluate variation in care practices to identify targets for improvement efforts.
Phased Array Feed (PAF) technology is the next major advancement in radio astronomy in terms of combining high sensitivity and large field of view. The Focal L-band Array for the Green Bank Telescope (FLAG) is one of the most sensitive PAFs developed so far. It consists of 19 dual-polarization elements mounted on a prime focus dewar resulting in seven beams on the sky. Its unprecedented system temperature of ~17 K will lead to a 3 fold increase in pulsar survey speeds as compared to contemporary single pixel feeds. Early science observations were conducted in a recently concluded commissioning phase of the FLAG where we clearly demonstrated its science capabilities. We observed a selection of normal and millisecond pulsars and detected giant pulses from PSR B1937+21.
Supernova remnants (SNRs) are powerful particle accelerators. As a supernova (SN) blast wave propagates through the circumstellar medium (CSM), electrons and protons scatter across the shock and gain energy by entrapment in the magnetic field. The accelerated particles generate further magnetic field fluctuations and local amplification, leading to cosmic ray production. The wealth of data from Supernova 1987A is providing a template of the SN-CSM interaction, and an important guide to the radio detection and identification of core-collapse SNe based on their spectral properties. Thirty years after the explosion, radio observations of SNR 1987A span from 70 MHz to 700 GHz. We review extensive observing campaigns with the Australia Telescope Compact Array (ATCA) and the Atacama Large Millimeter/submillimeter Array (ALMA), and follow-ups with other radio telescopes. Observations across the radio spectrum indicate rapid changes in the remnant morphology, while current ATCA and ALMA observations show that the SNR has entered a new evolutionary phase.
There are few quantitative studies on deep-sea biodiversity from the Indian Ocean, particularly on the mid-ocean ridges (MOR). We investigated the benthic megafaunal community structure of the Indian Ocean MOR at the Carlsberg Ridge (CR) using underwater video observation by the Television Gripper (TVG) and Ocean Floor Observation System (OFOS) during a multidisciplinary scientific cruise in 2007. Our aim was to observe megafaunal assemblages and their variation with bottom substrate at different geological settings in the CR region. The fauna was identified at best possible taxonomic resolution from video images and data were quantified by photogrammetry. Variation of substratum type was greatest in the deeper areas of the CR region, with substrata varying from fine sediments to basalts. A total of eight substratum types and 90 megafaunal taxa, representing seven phyla, have been classified throughout the 10 transects. Faunal abundances ranged between 171.3 to 5.7 animals 1000 m−2, with higher abundances at the shallower transects, in off-axial highs, and lower at deeper zones, on the rift valley wall and floor. Cnidarians were dominant at off-axial highs while echinoderms prevailed at rift valley floor transects. Other frequently encountered faunal components were poriferans and chordates, observed at shallower as well as deeper transects. This is the first detailed investigation of megafaunal assemblages from the Indian Ocean MOR.
Listeria monocytogenes is a foodborne pathogen that can cause bacteraemia, meningitis, and complications during pregnancy. In July 2012, molecular subtyping identified indistinguishable L. monocytogenes isolates from six patients and two samples of different cut and repackaged cheeses. A multistate outbreak investigation was initiated. Initial analyses identified an association between eating soft cheese and outbreak-related illness (odds ratio 17·3, 95% confidence interval 2·0–825·7) but no common brand. Cheese inventory data from locations where patients bought cheese and an additional location where repackaged cheese yielded the outbreak strain were compared to identify cheeses for microbiological sampling. Intact packages of imported ricotta salata yielded the outbreak strain. Fourteen jurisdictions reported 22 cases from March–October 2012, including four deaths and a fetal loss. Six patients ultimately reported eating ricotta salata; another reported eating cheese likely cut with equipment also used for contaminated ricotta salata, and nine more reported eating other cheeses that might also have been cross-contaminated. An FDA import alert and US and international recalls followed. Epidemiology-directed microbiological testing of suspect cheeses helped identify the outbreak source. Cross-contamination of cheese highlights the importance of using validated disinfectant protocols and routine cleaning and sanitizing after cutting each block or wheel.
Task-sharing is the involvement of non-specialist providers to deliver mental health services. A challenge for task-sharing programs is to achieve and maintain clinical competence of non-specialists, including primary care workers, paraprofessionals, and lay providers. We developed a tool for non-specialist peer ratings of common factors clinical competency to evaluate and optimize competence during training and supervision in global mental health task-sharing initiatives.
The 18-item ENhancing Assessment of Common Therapeutic factors (ENACT) tool was pilot-tested with non-specialists participating in mental health Gap Action Programme trainings in Nepal. Qualitative process evaluation was used to document development of the peer rating scoring system. Qualitative data included interviews with trainers and raters as well as transcripts of pre- and post-training observed structured clinical evaluations.
Five challenges for non-specialist peer ratings were identified through the process evaluation: (1) balance of training and supervision objectives with research objectives; (2) burden for peer raters due to number of scale items, number of response options, and use of behavioral counts; (3) capturing hierarchy of clinical skills; (4) objective v. subjective aspects of rating; and (5) social desirability when rating peers.
The process culminated in five recommendations based on the key findings for the development of scales to be used by non-specialists for peer ratings in low-resource settings. Further research is needed to determine the ability of ENACT to capture the relationship of clinical competence with client outcomes and to explore the relevance of these recommendations for non-specialist peer ratings in high-resource settings.
To estimate and compare the impact on healthcare costs of 3 alternative strategies for reducing bloodstream infections in the intensive care unit (ICU): methicillin-resistant Staphylococcus aureus (MRSA) nares screening and isolation, targeted decolonization (ie, screening, isolation, and decolonization of MRSA carriers or infections), and universal decolonization (ie, no screening and decolonization of all ICU patients).
Cost analysis using decision modeling.
We developed a decision-analysis model to estimate the health care costs of targeted decolonization and universal decolonization strategies compared with a strategy of MRSA nares screening and isolation. Effectiveness estimates were derived from a recent randomized trial of the 3 strategies, and cost estimates were derived from the literature.
In the base case, universal decolonization was the dominant strategy and was estimated to have both lower intervention costs and lower total ICU costs than either screening and isolation or targeted decolonization. Compared with screening and isolation, universal decolonization was estimated to save $171,000 and prevent 9 additional bloodstream infections for every 1,000 ICU admissions. The dominance of universal decolonization persisted under a wide range of cost and effectiveness assumptions.
A strategy of universal decolonization for patients admitted to the ICU would both reduce bloodstream infections and likely reduce healthcare costs compared with strategies of MRSA nares screening and isolation or screening and isolation coupled with targeted decolonization.
EMU is a wide-field radio continuum survey planned for the new Australian Square Kilometre Array Pathfinder (ASKAP) telescope. The primary goal of EMU is to make a deep (rms ∼ 10 μJy/beam) radio continuum survey of the entire Southern sky at 1.3 GHz, extending as far North as +30° declination, with a resolution of 10 arcsec. EMU is expected to detect and catalogue about 70 million galaxies, including typical star-forming galaxies up to z ∼ 1, powerful starbursts to even greater redshifts, and active galactic nuclei to the edge of the visible Universe. It will undoubtedly discover new classes of object. This paper defines the science goals and parameters of the survey, and describes the development of techniques necessary to maximise the science return from EMU.
In this work, we report the effect of high energy ball milling (HEBM) on Nb doped R2Fe16Nb1 (R= Gd, Er) compounds. The focus of the work is to bring enhancement in magnetic properties of R2Fe17 (2:17) compounds with the ball milling. Specifically, we find that the ball milling increases saturation magnetization, coercivity, and Curie temperature. The increase in the magnetization and Curie temperature upon ball milling is related to the lattice expansion and microstrains while the increase in coercivity is related to the grain refinement.
Nanostructured Al3+ doped Ni0.75Zn0.25Fe2-xAlxO4 (x = 0.0,0.2,0.4,0.6,0.8, and 1.0) ferrites were synthesized via wet chemical method. X-ray diffraction, transmission electron microscopy, and magnetization measurements have been used to investigate the structural and magnetic properties of spinel ferrites calcined at 950 °C .With the doping of Al3+, the particle size of Ni0.75Zn0.25Fe2-xAlxO4 first increased to 47 nm at x = 0.4 and then decreased down to 37 nm at x = 1. Saturation magnetization decreased linearly with Al3+ due to magnetic dilution. The coercive field showed an inverse dependence on the particle size of ferrites.
Magnetically separable and reusable core-shell CoFe2O4-ZnO photocatalyst nanospheres were prepared via hydrothermal synthesis technique using glucose derived carbon nanospheres as template. The morphology and phase of core-shell hybrid structure of CoFe2O4-ZnO was assessed via TEM, and XRD. The UV-vis photocatalytic activity of the composite was assessed via measuring the degradation rate of modeled pollutant methylene blue in water. The magnetic composite showed high UV photocatalytic activity for the degradation of methylene blue. The photocatalytic activity was found to be ZnO shell thickness dependent. Thicker ZnO shells lead to higher rate of photocatalytic activity. Hybrid nanospheres recovered using external magnetic field demonstrated good repeatability of photocatalytic activity. These results promise the reusability of hybrid nanospheres for photocatalytic activity.
Infrared to visible upconversion emission bands are observed in Nd3+:
LiTeO2 glass at 430, 482, 525, 535, 580, 600, 664 and 766 nm
wavelengths due to the 2P1/2
4I13/2 and 4G7/2
4I15/2 transitions, respectively. Mechanisms involved in these upconversion
emissions are shown to either involve excited state absorption or energy
transfer depending upon the concentration of the rare earth ions. The
emission bands at 755 and 968 nm are also observed due to the thermally
excited phonon absorption, on excitation with 800 nm wavelength. A 90 fold
enhancement in the intensity of anti-Stokes emission at 755 nm is observed
in this glass when temperature is raised from 298 to 523 K. Fluorescence
intensity ratio (FIR) and sensitivity (S) of the two thermally coupled
levels viz. 4F3/2 and 4F5/2 are calculated at different
temperatures and results show that these levels could act as temperature
sensor in tellurite host. Lifetimes of the excited levels 2P1/2,
4G7/2, 4F3/2, 4F5/2 and 4F7/2
involved in the emission process are also determined and their temperature
dependence is described.
Doping of thin body Si becomes very essential topic due to increasing interest of forming source/drain regions in fully depleted planar silicon-on-isolator (SOI) devices or vertical Fin field-effect-transistors (FinFETs). To diminish the role of the short-channel-control-effect (SCE) the Si layers thicknesses target the 10 nm range. In this paper many aspects of thin Si body doping are discussed: dopant retention, implantation-related amorphization, thin body recrystallization, sheet resistance (Rs) and carrier mobility in crystalline or amorphized material, impact of the annealing ambient on Rs for various SOI thicknesses. The complexity of 3D geometry for vertical Fin and the vicinity of the extended surface have an impact on doping strategies that are significantly different than for planar bulk devices.