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The Murchison Widefield Array (MWA) is an open access telescope dedicated to studying the low-frequency (80–300 MHz) southern sky. Since beginning operations in mid-2013, the MWA has opened a new observational window in the southern hemisphere enabling many science areas. The driving science objectives of the original design were to observe 21 cm radiation from the Epoch of Reionisation (EoR), explore the radio time domain, perform Galactic and extragalactic surveys, and monitor solar, heliospheric, and ionospheric phenomena. All together
programs recorded 20 000 h producing 146 papers to date. In 2016, the telescope underwent a major upgrade resulting in alternating compact and extended configurations. Other upgrades, including digital back-ends and a rapid-response triggering system, have been developed since the original array was commissioned. In this paper, we review the major results from the prior operation of the MWA and then discuss the new science paths enabled by the improved capabilities. We group these science opportunities by the four original science themes but also include ideas for directions outside these categories.
Exercise and physical training are known to affect gastrointestinal function and digestibility in horses and can lead to inaccurate estimates of nutrient and energy digestibility when markers are used. The effect of exercise on apparent nutrient digestibility and faecal recoveries of ADL and TiO2 was studied in six Welsh pony geldings subjected to either a low- (LI) or high-intensity (HI) exercise regime according to a cross-over design. Ponies performing LI exercise were walked once per day for 45 min in a horse walker (5 km/h) for 47 consecutive days. Ponies submitted to HI exercise were gradually trained for the same 47 days according a standardized protocol. Throughout the experiment, the ponies received a fixed level of feed and the daily rations consisted of 4.7 kg DM of grass hay and 0.95 kg DM of concentrate. The diet was supplemented with minerals, vitamins and TiO2 (3.0 g Ti/day). Total tract digestibility of DM, organic matter (OM), CP, crude fat, NDF, ADF, starch, sugar and energy was determined with the total faeces collection (TFC) method. In addition, DM and OM digestibility was estimated using internal ADL and the externally supplemented Ti as markers. Urine was collected on the final 2 days of each experimental period. Exercise did not affect apparent digestibility of CP, crude fat, starch and sugar. Digestibility of DM (DMD), OM (OMD), ADF and NDF tended to be lower and DE was decreased when ponies received the HI exercise regime. For all treatments combined, mean faecal recoveries of ADL and Ti were 87.8±1.7% and 99.3±1.7%, respectively. Ti was not detected in the urine, indicating that intestinal integrity was maintained with exercise. Dry matter digestibility estimated with the TFC, ADL and Ti for ponies subjected to LI exercise were 66.3%, 60.3% and 64.8%, respectively, while DMD for HI ponies were 64.2%, 60.3% and 65.2%, respectively. In conclusion, physical exercise has an influence on the GE digestibility of the feed in ponies provided with equivalent levels of feed intake. In addition, the two markers used for estimating apparent DMD and OMD indicate that externally supplemented Ti is a suitable marker to determine digestibility of nutrients in horses performing exercise unlike dietary ADL.
Across the globe, the implementation of quality improvement science and collaborative learning has positively affected the care and outcomes for children born with CHD. These efforts have advanced the collective expertise and performance of inter-professional healthcare teams. In this review, we highlight selected quality improvement initiatives and strategies impacting the field of cardiovascular care and describe implications for future practice and research. The continued leveraging of technology, commitment to data transparency, focus on team-based practice, and recognition of cultural norms and preferences ensure the success of sustainable models of global collaboration.
Since the first description of Wohlfahrtiimonas chitiniclastica in 2008, a number of well described case reports demonstrating its pathogenic role in humans have been published. Infections may be closely linked to flies, such as Wohlfahrtia magnifica, Lucilia sericata, Chrysomya megacephala or Musca domestica. These insects are potent vectors for the distribution of W. chitiniclastica causing local or systemic infections originating from wounds infested with fly larvae. However, other potential sources of transmission of W. chitiniclastica have been described such as soil or chicken meat. Infections in humans reported to date comprise wound infections, cellulitis, osteomyelitis and sepsis. This review summarizes all the literature available up to now and gives the current knowledge about this emerging human pathogen. Additionally, four patients with proven W. chitiniclastica infections treated at Dresden University Hospital between 2013 and 2015, are included. Special focus was placed on microbiological identification and antibiotic susceptibility testing of the pathogen.
The inclusion of competitive crop cultivars in crop rotations is an
important integrated weed management (IWM) tool. However, competitiveness is
often not considered a priority for breeding or cultivar selection by
growers. Field pea (Pisum sativum L.) is often considered a
poor competitor with weeds, but it is not known whether competitiveness
varies among semileafless cultivars. The objectives of this study were to
determine if semileafless field pea cultivars vary in their ability to
compete and/or withstand competition, as well as to identify aboveground
trait(s) that may be associated with increased competitive ability. Field
experiments were conducted in 2012 and 2013 at three locations in western
Canada. Fourteen semileafless field pea cultivars were included in the study
representing four different market classes. Cultivars were grown either in
the presence or absence of model weeds (wheat and canola), and competitive
ability of the cultivars was determined based on their ability to withstand
competition (AWC) and their ability to compete (AC). Crop yield, weed
biomass and weed fecundity varied among sites but not years. Cultivars
exhibited inconsistent differences in competitive ability, although cv.
Reward consistently exhibited the lowest AC and AWC. None of the traits
measured in this study correlated highly with competitive ability. However,
the highest-yielding cultivars generally were those that had the highest AC,
whereas cultivars that ranked highest for AWC were associated with lower
weed fecundity. Ranking the competitive ability of field pea cultivars could
be an important IWM tool for growers and agronomists.
We compare first-order (refractive) ionospheric effects seen by the MWA with the ionosphere as inferred from GPS data. The first-order ionosphere manifests itself as a bulk position shift of the observed sources across an MWA field of view. These effects can be computed from global ionosphere maps provided by GPS analysis centres, namely the CODE. However, for precision radio astronomy applications, data from local GPS networks needs to be incorporated into ionospheric modelling. For GPS observations, the ionospheric parameters are biased by GPS receiver instrument delays, among other effects, also known as receiver DCBs. The receiver DCBs need to be estimated for any non-CODE GPS station used for ionosphere modelling. In this work, single GPS station-based ionospheric modelling is performed at a time resolution of 10 min. Also the receiver DCBs are estimated for selected Geoscience Australia GPS receivers, located at Murchison Radio Observatory, Yarragadee, Mount Magnet and Wiluna. The ionospheric gradients estimated from GPS are compared with that inferred from MWA. The ionospheric gradients at all the GPS stations show a correlation with the gradients observed with the MWA. The ionosphere estimates obtained using GPS measurements show promise in terms of providing calibration information for the MWA.
The Murchison Widefield Array is a Square Kilometre Array Precursor. The telescope is located at the Murchison Radio–astronomy Observatory in Western Australia. The MWA consists of 4 096 dipoles arranged into 128 dual polarisation aperture arrays forming a connected element interferometer that cross-correlates signals from all 256 inputs. A hybrid approach to the correlation task is employed, with some processing stages being performed by bespoke hardware, based on Field Programmable Gate Arrays, and others by Graphics Processing Units housed in general purpose rack mounted servers. The correlation capability required is approximately 8 tera floating point operations per second. The MWA has commenced operations and the correlator is generating 8.3 TB day−1 of correlation products, that are subsequently transferred 700 km from the MRO to Perth (WA) in real-time for storage and offline processing. In this paper, we outline the correlator design, signal path, and processing elements and present the data format for the internal and external interfaces.
The Murchison Widefield Array is a new low-frequency interferometric radio telescope built in Western Australia at one of the locations of the future Square Kilometre Array. We describe the automated radio-frequency interference detection strategy implemented for the Murchison Widefield Array, which is based on the aoflagger platform, and present 72–231 MHz radio-frequency interference statistics from 10 observing nights. Radio-frequency interference detection removes 1.1% of the data. Radio-frequency interference from digital TV is observed 3% of the time due to occasional ionospheric or atmospheric propagation. After radio-frequency interference detection and excision, almost all data can be calibrated and imaged without further radio-frequency interference mitigation efforts, including observations within the FM and digital TV bands. The results are compared to a previously published Low-Frequency Array radio-frequency interference survey. The remote location of the Murchison Widefield Array results in a substantially cleaner radio-frequency interference environment compared to Low-Frequency Array’s radio environment, but adequate detection of radio-frequency interference is still required before data can be analysed. We include specific recommendations designed to make the Square Kilometre Array more robust to radio-frequency interference, including: the availability of sufficient computing power for radio-frequency interference detection; accounting for radio-frequency interference in the receiver design; a smooth band-pass response; and the capability of radio-frequency interference detection at high time and frequency resolution (second and kHz-scale respectively).
We present the results of an approximately 6 100 deg2 104–196 MHz radio sky survey performed with the Murchison Widefield Array during instrument commissioning between 2012 September and 2012 December: the MWACS. The data were taken as meridian drift scans with two different 32-antenna sub-arrays that were available during the commissioning period. The survey covers approximately 20.5 h < RA < 8.5 h, − 58° < Dec < −14°over three frequency bands centred on 119, 150 and 180 MHz, with image resolutions of 6–3 arcmin. The catalogue has 3 arcmin angular resolution and a typical noise level of 40 mJy beam− 1, with reduced sensitivity near the field boundaries and bright sources. We describe the data reduction strategy, based upon mosaicked snapshots, flux density calibration, and source-finding method. We present a catalogue of flux density and spectral index measurements for 14 110 sources, extracted from the mosaic, 1 247 of which are sub-components of complexes of sources.
Intrauterine factors important for cognitive development, such as birth weight, chorionicity and umbilical cord characteristics were investigated. A total of 663 twin pairs completed the Wechsler Intelligence Scale for Children-Revised and scores were available for Performance, Verbal and Total Intelligence Quotient (IQ). The intrauterine factors examined were birth weight, placental weight and morphology, cord knots, cord length and cord insertion. IQ scores for the varying levels of the intrauterine markers adjusting for gender and gestational age were calculated. The heritability of IQ and the association between IQ and intrauterine environment were examined. Twins with lower birth weight and cord knots had lower IQ scores. The aetiology of IQ is largely distinct from that of birth weight and cord knots, and non-shared environment may influence the observed relationships.
Resonant substrate integrated near-field sensors are used for characterization of aqueous solutions at three different frequencies. In addition, Chinese hamster ovary (CHO) cells in a culture medium are characterized with the same sensors. Different concentrations as well as different vital states of cell suspensions are examined. The complex permittivity of the samples is evaluated using a linearized method based on perturbation theory. The permittivity differences between the measured cell suspensions are discussed. The resonant frequencies of the sensors are close to 3, 7, and 11 GHz, respectively.
A new technology to size nanoparticles in liquids is presented. The technique is based on aerosol technology coupled to a nanoparticle nebulizer. This allows number concentration measurements in the size range ca. 5 to 500 nm with high peak resolution.
The Netherlands Twin Register (NTR) began in 1987 with data collection in twins and their families, including families with newborn twins and triplets. Twenty-five years later, the NTR has collected at least one survey for 70,784 children, born after 1985. For the majority of twins, longitudinal data collection has been done by age-specific surveys. Shortly after giving birth, mothers receive a first survey with items on pregnancy and birth. At age 2, a survey on growth and achievement of milestones is sent. At ages 3, 7, 9/10, and 12 parents and teachers receive a series of surveys that are targeted at the development of emotional and behavior problems. From age 14 years onward, adolescent twins and their siblings report on their behavior problems, health, and lifestyle. When the twins are 18 years and older, parents are also invited to take part in survey studies. In sub-groups of different ages, in-depth phenotyping was done for IQ, electroencephalography , MRI, growth, hormones, neuropsychological assessments, and cardiovascular measures. DNA and biological samples have also been collected and large numbers of twin pairs and parents have been genotyped for zygosity by either micro-satellites or sets of short nucleotide polymorphisms and repeat polymorphisms in candidate genes. Subject recruitment and data collection is still ongoing and the longitudinal database is growing. Data collection by record linkage in the Netherlands is beginning and we expect these combined longitudinal data to provide increased insights into the genetic etiology of development of mental and physical health in children and adolescents.
Prior studies examining the association between self-reported experiences of racial/ethnic discrimination and obesity have had mixed results and primarily been cross-sectional. This study tests the hypothesis that an increase in self-reported experiences of racial/ethnic discrimination predicts gains in waist circumference and body mass index in Black and White women and men over eight years. In race/ethnicity- and gender-stratified models, this study examined whether change in self-reported experiences of racial/ethnic discrimination predicts changes in waist circumference and body mass index over time using a fixed-effects regression approach in SAS statistical software, providing control for both measured and unmeasured time-invariant covariates. Between 1992–93 and 2000–01, self-reported experiences of racial/ethnic discrimination decreased among 843 Black women (75% to 73%), 601 Black men (80% to 77%), 893 White women (30% to 23%) and 856 White men (28% to 23%). In fixed-effects regression models, controlling for all time-invariant covariates, social desirability bias, and changes in education and parity (women only) over time, an increase in self-reported experiences of racial/ethnic discrimination over time was significantly associated with an increase in waist circumference (β=1.09, 95% CI: 0.00–2.19, p=0.05) and an increase in body mass index (β=0.67, 95% CI: 0.19–1.16, p=0.007) among Black women. No associations were observed among Black men and White women and men. These findings suggest that an increase in self-reported experiences of racial/ethnic discrimination may be associated with increases in waist circumference and body mass index among Black women over time.