To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
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.
Neonates are at high risk of bleeding after open-heart surgery. We sought to determine pre-operative and intra-operative risk factors for increased bleeding after neonatal open-heart surgery with cardiopulmonary bypass.
We conducted a retrospective cohort study of neonates (0–30 days old) who underwent open-heart surgery with cardiopulmonary bypass from January, 2009, to March, 2013. Cardiac diagnosis; demographic and surgical data; and blood products, haemostatic agents, and anti-thrombotic agents administered before, during, and within 24 hours after surgery were abstracted from the electronic health record and anaesthesia records. The outcome of interest was chest tube output (in ml/kg body weight) within 24 hours. Relationships between chest tube output and putative associated factors were evaluated by unadjusted and adjusted linear regression.
The cohort consisted of 107 neonates, of whom 79% had a Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery (STAT) Mortality Category of 4 or 5. Median chest tube output was 37 ml/kg (range 9–655 ml/kg). Age, African-American race, and longer durations of surgery and cardiopulmonary bypass each had statistically significant associations with increased chest tube output in unadjusted analyses. In multivariable analysis, African-American race retained an independent, statistically significant association with increased chest tube output; the geometric mean of chest tube output among African-American neonates was 71% higher than that of Caucasians (95% confidence interval, 29–125%; p = 0.001).
Among neonates with CHD undergoing open-heart surgery with cardiopulmonary bypass, African-American race is independently associated with greater chest tube output over the first 24 hours post-operatively.
The Single Ventricle Reconstruction Trial randomised neonates with hypoplastic left heart syndrome to a shunt strategy but otherwise retained standard of care. We aimed to describe centre-level practice variation at Fontan completion.
Centre-level data are reported as median or median frequency across all centres and range of medians or frequencies across centres. Classification and regression tree analysis assessed the association of centre-level factors with length of stay and percentage of patients with prolonged pleural effusion (>7 days).
The median Fontan age (14 centres, 320 patients) was 3.1 years (range from 1.7 to 3.9), and the weight-for-age z-score was −0.56 (−1.35 + 0.44). Extra-cardiac Fontans were performed in 79% (4–100%) of patients at the 13 centres performing this procedure; lateral tunnels were performed in 32% (3–100%) at the 11 centres performing it. Deep hypothermic circulatory arrest (nine centres) ranged from 6 to 100%. Major complications occurred in 17% (7–33%). The length of stay was 9.5 days (9–12); 15% (6–33%) had prolonged pleural effusion. Centres with fewer patients (<6%) with prolonged pleural effusion and fewer (<41%) complications had a shorter length of stay (<10 days; sensitivity 1.0; specificity 0.71; area under the curve 0.96). Avoiding deep hypothermic circulatory arrest and higher weight-for-age z-score were associated with a lower percentage of patients with prolonged effusions (<9.5%; sensitivity 1.0; specificity = 0.86; area under the curve 0.98).
Fontan perioperative practices varied widely among study centres. Strategies to decrease the duration of pleural effusion and minimise complications may decrease the length of stay. Further research regarding deep hypothermic circulatory arrest is needed to understand its association with prolonged pleural effusion.
Meta-analyses suggest that clinical psychopathology is preceded by dimensional behavioral and cognitive phenotypes such as psychotic experiences, executive functioning, working memory and affective dysregulation that are determined by the interplay between genetic and nongenetic factors contributing to the severity of psychopathology. The liability to mental ill health can be psychometrically measured using experimental paradigms that assess neurocognitive processes such as salience attribution, sensitivity to social defeat and reward sensitivity. Here, we describe the TwinssCan, a longitudinal general population twin cohort, which comprises 1202 individuals (796 adolescent/young adult twins, 43 siblings and 363 parents) at baseline. The TwinssCan is part of the European Network of National Networks studying Gene-Environment Interactions in Schizophrenia project and recruited from the East Flanders Prospective Twin Survey. The main objective of this project is to understand psychopathology by evaluating the contribution of genetic and nongenetic factors on subclinical expressions of dimensional phenotypes at a young age before the onset of disorder and their association with neurocognitive processes, such as salience attribution, sensitivity to social defeat and reward sensitivity.
To develop a physiological data-driven model for early identification of impending cardiac arrest in neonates and infants with cardiac disease hospitalised in the cardiovascular ICU.
We performed a single-institution retrospective cohort study (11 January 2013–16 September 2015) of patients ≤1 year old with cardiac disease who were hospitalised in the cardiovascular ICU at a tertiary care children’s hospital. Demographics and diagnostic codes of cardiac arrest were obtained via the electronic health record. Diagnosis of cardiac arrest was validated by expert clinician review. Minute-to-minute physiological monitoring data were recorded via bedside monitors. A generalized linear model was used to compute a minute by minute risk score. Training and test data sets both included data from patients who did and did not develop cardiac arrest. An optimal risk-score threshold was derived based on the model’s discriminatory capacity for impending arrest versus non-arrest. Model performance measures included sensitivity, specificity, accuracy, likelihood ratios, and post-test probability of arrest.
The final model consisting of multiple clinical parameters was able to identify impending cardiac arrest at least 2 hours prior to the event with an overall accuracy of 75% (sensitivity = 61%, specificity = 80%) and observed an increase in probability of detection of cardiac arrest from a pre-test probability of 9.6% to a post-test probability of 21.2%.
Our findings demonstrate that a predictive model using physiologic monitoring data in neonates and infants with cardiac disease hospitalised in the paediatric cardiovascular ICU can identify impending cardiac arrest on average 17 hours prior to arrest.
On many Australian commercial pig farms, groups of growing pigs are mass-medicated through their drinking water with selected antimicrobials for short periods to manage herd health. However, delivery of medication in drinking water cannot be assumed to deliver an equal dose to all animals in a group. There is substantial between-animal variability in systemic exposure to an antimicrobial (i.e. the antimicrobial concentration in plasma), resulting in under-dosing or over-dosing of many pigs. Three sources of this between-animal variability during a water medication dosing event are differences in: (1) concentration of the active constituent of the antimicrobial product in water available to pigs at drinking appliances in each pen over time, (2) medicated water consumption patterns of pigs in each pen over time, and (3) pharmacokinetics (i.e. oral bioavailability, volume of distribution and clearance between pigs and within pigs over time). It is essential that factors operating on each farm that influence the range of systemic exposures of pigs to an antimicrobial are factored into antimicrobial administration regimens to reduce under-dosing and over-dosing.
Medical residents are an important group for antimicrobial stewardship programs (ASPs) to target with interventions aimed at improving antibiotic prescribing. In this study, we compared antimicrobial prescribing practices of 2 academic medical teams receiving different ASP training approaches along with a hospitalist control group.
Retrospective cohort study comparing guideline-concordant antibiotic prescribing for 3 common infections among a family medicine (FM) resident service, an internal medicine (IM) resident service, and hospitalists.
Community teaching hospital.
Adult patients admitted between July 1, 2016, and June 30, 2017, with a discharge diagnosis of pneumonia, cellulitis, and urinary tract infections were reviewed.
All 3 medical teams received identical baseline ASP education and daily antibiotic prescribing audit with feedback via clinical pharmacists. The FM resident service received an additional layer of targeted ASP intervention that included biweekly stewardship-focused rounds with an ASP physician and clinical pharmacist leadership. Guideline-concordant prescribing was assessed based on the institution’s ASP guidelines.
Of 1,572 patients, 295 (18.8%) were eligible for inclusion (FM, 96; IM, 69; hospitalist, 130). The percentage of patients receiving guideline-concordant antibiotic selection empirically was similar between groups for all diagnoses (FM, 87.5%; IM, 87%; hospitalist, 83.8%; P = .702). No differences were observed in appropriate definitive antibiotic selection among groups (FM, 92.4%; IM, 89.1%; hospitalist, 89.9%; P = .746). The FM resident service was more likely to prescribe a guideline-concordant duration of therapy across all diagnoses (FM, 74%; IM, 56.5%; hospitalist, 44.6%; P < .001).
Adding dedicated stewardship-focused rounds into the graduate medical curriculum demonstrated increased guideline adherence specifically to duration of therapy recommendations.
Recent years have seen an exponential increase in the variety of healthcare data captured across numerous sources. However, mechanisms to leverage these data sources to support scientific investigation have remained limited. In 2013 the Pediatric Heart Network (PHN), funded by the National Heart, Lung, and Blood Institute, developed the Integrated CARdiac Data and Outcomes (iCARD) Collaborative with the goals of leveraging available data sources to aid in efficiently planning and conducting PHN studies; supporting integration of PHN data with other sources to foster novel research otherwise not possible; and mentoring young investigators in these areas. This review describes lessons learned through the development of iCARD, initial efforts and scientific output, challenges, and future directions. This information can aid in the use and optimisation of data integration methodologies across other research networks and organisations.
The current methodology for calculating central-line–associated bloodstream infection (CLABSI) rates, used for pay-for-performance measures, does not account for multiple concurrent central lines.
To compare CLABSI rates using standard National Healthcare Safety Network (NHSN) denominators to rates accounting for multiple concurrent central lines.
Descriptive analysis and retrospective cohort analysis.
We identified all adult patients with central lines at 2 academic medical centers over an 18-month period. CLABSI rates were calculated for intensive care units (ICUs) and non-ICUs using the standard NHSN methodology and denominator (a patient could only have 1 central-line day for a given patient day) and a modified denominator (number of central lines in 1 patient in 1 day count as number of line days). We also compared characteristics of patients with and without multiple concurrent central lines.
Among 18,521 hospital admissions, there were 156,574 central-line days and 239 CLABSIs (ICU, 105; non-ICU, 134). Our modified denominator reduced CLABSI rates by 25% in ICUs (1.95 vs 1.47 per 1,000 line days) and 6% (1.30 vs 1.22 per 1,000 line days) in non-ICUs. Patients with multiple concurrent central lines were more likely to be in an ICU, to have a longer admission, to have a dialysis catheter, and to have a CLABSI.
Using the number of central lines as the denominator decreased CLABSI rates in ICUs by 25%. The presence of multiple concurrent central lines may be a marker of severity of illness. The risk of CLABSI per lumen of a central line is similar in ICUs compared to wards.
Children breast-fed during infancy consume more fruits and vegetables than formula-fed children. This pattern is likely due, in part, to infant learning from flavours of the mother’s diet transmitted through breast milk, but more research is needed to understand associations between early flavour exposures and later dietary patterns. We examined whether breast-feeding and maternal fruit and vegetable consumption during nursing were synergistically associated with higher child fruit and vegetable consumption.
Prospective cohort study of breast-feeding duration, maternal diet postpartum and child diet. Complete breast-feeding and maternal diet data were available for 1396 mother–child dyads; multiple imputation was used for missing data in other variables. In separate multivariable logistic regression models, we estimated the adjusted odds of high child fruit or vegetable consumption at 12 months or 6 years as a function of breast-feeding duration, maternal fruit or vegetable consumption during nursing, and their interaction.
The Infant Feeding Practices Study II and Year 6 Follow-Up.
Mother–child dyads followed from birth to 6 years during 2005–2012 in the USA.
Longer breast-feeding duration was associated with high child fruit and vegetable consumption at 12 months. At 6 years, the interaction between breast-feeding duration and maternal vegetable consumption was associated with high child vegetable consumption.
Higher maternal vegetable consumption and longer breast-feeding duration were synergistically associated with high child vegetable consumption at 6 years, independent of sociodemographic characteristics and fruit and vegetable availability. Exposures to vegetable flavours through breast milk may promote later child vegetable consumption.
To evaluate the association between novel pre- and post-operative biomarker levels and 30-day unplanned readmission or mortality after paediatric congenital heart surgery.
Children aged 18 years or younger undergoing congenital heart surgery (n = 162) at Johns Hopkins Hospital from 2010 to 2014 were enrolled in the prospective cohort. Collected novel pre- and post-operative biomarkers include soluble suppression of tumorgenicity 2, galectin-3, N-terminal prohormone of brain natriuretic peptide, and glial fibrillary acidic protein. A model based on clinical variables from the Society of Thoracic Surgery database was developed and evaluated against two augmented models.
Unplanned readmission or mortality within 30 days of cardiac surgery occurred among 21 (13%) children. The clinical model augmented with pre-operative biomarkers demonstrated a statistically significant improvement over the clinical model alone with a receiver-operating characteristics curve of 0.754 (95% confidence interval: 0.65–0.86) compared to 0.617 (95% confidence interval: 0.47–0.76; p-value: 0.012). The clinical model augmented with pre- and post-operative biomarkers demonstrated a significant improvement over the clinical model alone, with a receiver-operating characteristics curve of 0.802 (95% confidence interval: 0.72–0.89; p-value: 0.003).
Novel biomarkers add significant predictive value when assessing the likelihood of unplanned readmission or mortality after paediatric congenital heart surgery. Further exploration of the utility of these novel biomarkers during the pre- or post-operative period to identify early risk of mortality or readmission will aid in determining the clinical utility and application of these biomarkers into routine risk assessment.
The present study investigated the ability of the Multilingual Naming Test (MINT), a picture naming test recently added to the National Alzheimer’s Coordinating Center’s (NACC) Uniform Data Set neuropsychological test battery, to detect naming impairment (i.e., dysnomia) across stages of Alzheimer’s disease (AD).
Data from the initial administration of the MINT were obtained on NACC participants who were cognitively normal (N = 3,981) or diagnosed with mild cognitive impairment (N = 852) or dementia (N = 1,148) with presumed etiology of AD. Dementia severity was rated using the Clinical Dementia Rating (CDR) scale.
Cross-sectional multiple regression analyses revealed significant effects of diagnostic group, sex, education, age, and race on naming scores. Planned comparisons collapsing across age and education groups revealed significant group differences in naming scores across levels of dementia severity. ROC curve analyses showed good diagnostic accuracy of MINT scores for distinguishing cognitively normal controls from AD dementia, but not from MCI. Within the cognitively normal group, there was a robust interaction between age and education such that naming scores exhibited the most precipitous drop across age groups for the least educated participants. Additionally, education effects were stronger in African-Americans than in Whites (a race-by-education interaction), and race effects were stronger in older than in younger age groups (a race-by-age interaction).
The MINT successfully detects naming deficits at different levels of cognitive impairment in patients with MCI or AD dementia, but comparison to age, sex, race, and education-corrected norms to determine impairment is essential.
Antipseudomonal carbapenems are an important target for antimicrobial stewardship programs. We evaluated the impact of formulary restriction and preauthorization on relative carbapenem use for medical and surgical intensive care units at a large, urban academic medical center using interrupted time-series analysis.
To properly understand the tectonic history of the Grenville Province it is necessary to have a reliable, scientifically based understanding of the present-day three-dimensional (3D) structure of the orogen. Based on detailed Nd isotope mapping of surface boundaries and Lithoprobe seismic sections, this study provides the first detailed visualization of the 3D structure of the Grenville gneiss belt in Ontario using the SketchUp software package. The 3D visualization supports a model in which thrust geometry was imposed from the top downwards, controlled by the NW boundary of the Central Metasedimentary Belt that originated as a failed back-arc rift zone. The Central Metasedimentary Belt boundary controlled the trajectory of the Allochthon Boundary Thrust, its underlying tectonic duplex and, ultimately, the Grenville Front. This process of superimposed thrusting explains the large-scale change in the trajectory of the Grenville Front north of Georgian Bay that has been called the ‘Big Bend’. To assist in visualizing the 3D model, a fly-through animation is provided in the supplementary material.
Using existing data from clinical registries to support clinical trials and other prospective studies has the potential to improve research efficiency. However, little has been reported about staff experiences and lessons learned from implementation of this method in pediatric cardiology.
We describe the process of using existing registry data in the Pediatric Heart Network Residual Lesion Score Study, report stakeholders’ perspectives, and provide recommendations to guide future studies using this methodology.
The Residual Lesion Score Study, a 17-site prospective, observational study, piloted the use of existing local surgical registry data (collected for submission to the Society of Thoracic Surgeons-Congenital Heart Surgery Database) to supplement manual data collection. A survey regarding processes and perceptions was administered to study site and data coordinating center staff.
Survey response rate was 98% (54/55). Overall, 57% perceived that using registry data saved research staff time in the current study, and 74% perceived that it would save time in future studies; 55% noted significant upfront time in developing a methodology for extracting registry data. Survey recommendations included simplifying data extraction processes and tailoring to the needs of the study, understanding registry characteristics to maximise data quality and security, and involving all stakeholders in design and implementation processes.
Use of existing registry data was perceived to save time and promote efficiency. Consideration must be given to the upfront investment of time and resources needed. Ongoing efforts focussed on automating and centralising data management may aid in further optimising this methodology for future studies.