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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.
Objectives: This study aimed to evaluate the influence of lower limb loss (LL) on mental workload by assessing neurocognitive measures in individuals with unilateral transtibial (TT) versus those with transfemoral (TF) LL while dual-task walking under varying cognitive demand. Methods: Electroencephalography (EEG) was recorded as participants performed a task of varying cognitive demand while being seated or walking (i.e., varying physical demand). Results: The findings revealed both groups of participants (TT LL vs. TF LL) exhibited a similar EEG theta synchrony response as either the cognitive or the physical demand increased. Also, while individuals with TT LL maintained similar performance on the cognitive task during seated and walking conditions, those with TF LL exhibited performance decrements (slower response times) on the cognitive task during the walking in comparison to the seated conditions. Furthermore, those with TF LL neither exhibited regional differences in EEG low-alpha power while walking, nor EEG high-alpha desynchrony as a function of cognitive task difficulty while walking. This lack of alpha modulation coincided with no elevation of theta/alpha ratio power as a function of cognitive task difficulty in the TF LL group. Conclusions: This work suggests that both groups share some common but also different neurocognitive features during dual-task walking. Although all participants were able to recruit neural mechanisms critical for the maintenance of cognitive-motor performance under elevated cognitive or physical demands, the observed differences indicate that walking with a prosthesis, while concurrently performing a cognitive task, imposes additional cognitive demand in individuals with more proximal levels of amputation.
The stellar winds of hot stars have an important impact on both stellar and galactic evolution, yet their structure and internal processes are not fully understood in detail. One of the best nearby laboratories for studying such massive stellar winds is the O4I(n)fp star ζ Pup. After briefly discussing existing X-ray observations from Chandra and XMM, we present a simulation of X-ray emission line profile measurements for the upcoming 840 kilosecond Chandra HETGS observation. This simulation indicates that the increased S/N of this new observation will allow several major steps forward in the understanding of massive stellar winds. By measuring X-ray emission line strengths and profiles, we should be able to differentiate between various stellar wind models and map the entire wind structure in temperature and density. This legacy X-ray spectrum of ζ Pup will be a useful benchmark for future X-ray missions.
Hypertrophic cardiomyopathy has a range of clinical severity in children. Treatment options are limited, mainly on account of small patient size. Disopyramide is a sodium channel blocker with negative inotropic properties that effectively reduces left ventricular outflow tract gradients in adults with hypertrophic cardiomyopathy, but its efficacy in children is uncertain. A retrospective chart review of patients ⩽21 years of age with hypertrophic cardiomyopathy at our institution and treated with disopyramide was performed. Left ventricular outflow tract Doppler gradients before and after disopyramide initiation were compared as the primary outcome measure. Nine patients received disopyramide, with a median age of 5.6 years (range 6 days–12.9 years). The median left ventricular outflow tract Doppler gradient before initiation of disopyramide was 81 mmHg (range 30–132 mmHg); eight patients had post-initiation echocardiograms, in which the median lowest recorded Doppler gradient was 43 mmHg (range 15–100 mmHg), for a median % reduction of 58.2% (p=0.002). With median follow-up of 2.5 years, eight of nine patients were still alive, although disopyramide had been discontinued in six of the nine patients. Reasons for discontinuation included septal myomectomy (four patients), heart transplantation (one patient), and side effects (one patient). Disopyramide was effective for the relief of left ventricular outflow tract obstruction in children with hypertrophic cardiomyopathy, although longer-term data suggest that its efficacy is not sustained. In general, it was well tolerated. Further study in larger patient populations is warranted.
Intrauterine or fetal growth restriction (IUGR) is a major complication of pregnancy and leads to significant perinatal morbidities and mortality. Typically, induction of IUGR in animals involves the complete occlusion or ablation of vessels to the uterus or placenta, acutely impairing blood flow and fetal growth, usually with high fetal loss. We aimed to produce a model of reduced fetal growth in the spiny mouse with minimal fetal loss. At 27 days gestational age (term is 38–39 days), a piece of silastic tubing was placed around the left uterine artery to prevent the further increase of uterine blood flow with advancing gestation to induce IUGR (occluded). Controls were generated from sham surgeries without placement of the tubing. Dams were humanely euthanized at 37 days gestational age and all fetuses and placentas were weighed and collected. Of the 17 dams that underwent surgery, 15 carried their pregnancies to 37 days gestational age and 95% of fetuses survived to this time. The difference in fetal body weight between occluded and control was ~21% for fetuses in the left uterus side: there were no differences for fetuses in the right uterus side. Offspring from the occluded group had significantly lower brain, liver, lung, kidney and carcass weights compared with shams. Preventing the gestation-related increase of uterine blood flow induced significant growth restriction in the fetal spiny mouse, with minimal fetal loss. This technique could be readily adapted for other small animal.
Strategies that reduce the time to antimicrobial administration, such as the availability of premix antimicrobials (PMAs) in the emergency department (ED), may better align with the goals of the Surviving Sepsis Campaign and improve outcomes in septic patients. The objective of this study was to evaluate the impact of antimicrobial preparation on time to administration in septic patients located in the emergency department (ED).
This was a retrospective, single-center, cohort study and adult patients with a diagnosis of sepsis who received at least one initial intravenous (IV) antimicrobial in the ED were included. Time to complete an empiric antimicrobial therapy was defined as the time between prescriber order entry and the infusion initiation time of the final antimicrobial agent of a patient’s antimicrobial regimen. Appropriate, empiric antimicrobial therapy was based on treatment recommendations by nationally accepted guidelines for the specific indication.
The first antimicrobial was initiated earlier when available as a PMA preparation (median (IQR): premix 25 minutes (16.5-42.3) vs. non-premix 46 minutes (20-102), p=0.027). When comparing complete, empiric antimicrobial regimen administration, there was no difference in time to administration between regimens containing one or more non-premix antimicrobials and regimens containing all PMAs (median (IQR): premix 69 minutes (21-115) vs. non-premix 65 minutes (38.5-133.8); p=0.455).
PMA preparations significantly reduced time to administration of the first antimicrobial agent for septic patients treated in the ED, but time to administration of subsequent antimicrobials were not improved.
The objective of this study was to determine whether hatha yoga is an efficacious adjunctive intervention for individuals with continued depressive symptoms despite antidepressant treatment.
We conducted a randomized controlled trial of weekly yoga classes (n = 63) v. health education classes (Healthy Living Workshop; HLW; n = 59) in individuals with elevated depression symptoms and antidepressant medication use. HLW served as an attention-control group. The intervention period was 10 weeks, with follow-up assessments 3 and 6 months afterwards. The primary outcome was depression symptom severity assessed by blind rater at 10 weeks. Secondary outcomes included depression symptoms over the entire intervention and follow-up periods, social and role functioning, general health perceptions, pain, and physical functioning.
At 10 weeks, we did not find a statistically significant difference between groups in depression symptoms (b = −0.82, s.e. = 0.88, p = 0.36). However, over the entire intervention and follow-up period, when controlling for baseline, yoga participants showed lower levels of depression than HLW participants (b = −1.38, s.e. = 0.57, p = 0.02). At 6-month follow-up, 51% of yoga participants demonstrated a response (⩾50% reduction in depression symptoms) compared with 31% of HLW participants (odds ratio = 2.31; p = 0.04). Yoga participants showed significantly better social and role functioning and general health perceptions over time.
Although we did not see a difference in depression symptoms at the end of the intervention period, yoga participants showed fewer depression symptoms over the entire follow-up period. Benefits of yoga may accumulate over time.
The Dark Energy Survey is undertaking an observational programme imaging 1/4 of the southern hemisphere sky with unprecedented photometric accuracy. In the process of observing millions of faint stars and galaxies to constrain the parameters of the dark energy equation of state, the Dark Energy Survey will obtain pre-discovery images of the regions surrounding an estimated 100 gamma-ray bursts over 5 yr. Once gamma-ray bursts are detected by, e.g., the Swift satellite, the DES data will be extremely useful for follow-up observations by the transient astronomy community. We describe a recently-commissioned suite of software that listens continuously for automated notices of gamma-ray burst activity, collates information from archival DES data, and disseminates relevant data products back to the community in near-real-time. Of particular importance are the opportunities that non-public DES data provide for relative photometry of the optical counterparts of gamma-ray bursts, as well as for identifying key characteristics (e.g., photometric redshifts) of potential gamma-ray burst host galaxies. We provide the functional details of the DESAlert software, and its data products, and we show sample results from the application of DESAlert to numerous previously detected gamma-ray bursts, including the possible identification of several heretofore unknown gamma-ray burst hosts.
The drinking water infrastructure in the United States is ageing; extreme weather events place additional stress on water systems that can lead to interruptions in the delivery of safe drinking water. We investigated the association between household exposures to water service problems and acute gastrointestinal illness (AGI) and acute respiratory illness (ARI) in Alabama communities that experienced a freeze-related community-wide water emergency. Following the water emergency, investigators conducted a household survey. Logistic regression models were used to estimate adjusted prevalence ratios (aPR) and 95% confidence intervals (CI) for self-reported AGI and ARI by water exposures. AGI was higher in households that lost water service for ⩾7 days (aPR 2·4, 95% CI 1·1–5·2) and experienced low water pressure for ⩾7 days (aPR 3·6, 95% CI 1·4–9·0) compared to households that experienced normal service and pressure; prevalence of AGI increased with increasing duration of water service interruptions. Investments in the ageing drinking water infrastructure are needed to prevent future low-pressure events and to maintain uninterrupted access to the fundamental public health protection provided by safe water supplies. Households and communities need to increase their awareness of and preparedness for water emergencies to mitigate adverse health impacts.
Antarctic and Southern Ocean science is vital to understanding natural variability, the processes that govern global change and the role of humans in the Earth and climate system. The potential for new knowledge to be gained from future Antarctic science is substantial. Therefore, the international Antarctic community came together to ‘scan the horizon’ to identify the highest priority scientific questions that researchers should aspire to answer in the next two decades and beyond. Wide consultation was a fundamental principle for the development of a collective, international view of the most important future directions in Antarctic science. From the many possibilities, the horizon scan identified 80 key scientific questions through structured debate, discussion, revision and voting. Questions were clustered into seven topics: i) Antarctic atmosphere and global connections, ii) Southern Ocean and sea ice in a warming world, iii) ice sheet and sea level, iv) the dynamic Earth, v) life on the precipice, vi) near-Earth space and beyond, and vii) human presence in Antarctica. Answering the questions identified by the horizon scan will require innovative experimental designs, novel applications of technology, invention of next-generation field and laboratory approaches, and expanded observing systems and networks. Unbiased, non-contaminating procedures will be required to retrieve the requisite air, biota, sediment, rock, ice and water samples. Sustained year-round access to Antarctica and the Southern Ocean will be essential to increase winter-time measurements. Improved models are needed that represent Antarctica and the Southern Ocean in the Earth System, and provide predictions at spatial and temporal resolutions useful for decision making. A co-ordinated portfolio of cross-disciplinary science, based on new models of international collaboration, will be essential as no scientist, programme or nation can realize these aspirations alone.
Yellow archangel is a twining perennial species that produces a dense evergreen canopy and may negatively affect forest floor vegetation. Because it is spreading rapidly in the Pacific Northwest (PNW), greenhouse and field trials were conducted on yellow archangel to determine its relative sensitivity to several herbicides. Products that slowed or prevented yellow archangel regrowth at 9 mo after treatment (MAT) in one or both iterations of the greenhouse trial were aminopyralid, diclobenil, glufosinate, imazapyr, isoxaben, metsulfuron, sulfometuron, triclopyr amine, and triclopyr ester + 2,4-D ester. In the field trial at 10 MAT, triclopyr and imazapyr were controlling 81 and 78% of treated yellow archangel, respectively, similar to aminopyralid, glyphosate, and metsulfuron (61 to 65%). Two applications of 20% acetic acid or 20% clove oil were controlling 53% at the same timing. At 13 MAT, only imazapyr and glyphosate were still providing good control of yellow archangel (81 and 80%, respectively), while all other products were controlling the weed at 53% or less. By 7 or 8 MAT after a second application, only imazapyr and glyphosate provided effective control of yellow archangel (86 to 94%).