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We describe the design and deployment of GREENBURST, a commensal Fast Radio Burst (FRB) search system at the Green Bank Telescope. GREENBURST uses the dedicated L-band receiver tap to search over the 960–1 920 MHz frequency range for pulses with dispersion measures out to
. Due to its unique design, GREENBURST is capable of conducting searches for FRBs when the L-band receiver is not being used for scheduled observing. This makes it a sensitive single pixel detector capable of reaching deeper in the radio sky. While single pulses from Galactic pulsars and rotating radio transients will be detectable in our observations, and will form part of the database we archive, the primary goal is to detect and study FRBs. Based on recent determinations of the all-sky rate, we predict that the system will detect approximately one FRB for every 2–3 months of continuous operation. The high sensitivity of GREENBURST means that it will also be able to probe the slope of the FRB fluence distribution, which is currently uncertain in this observing band.
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.
We apply two methods to estimate the 21-cm bispectrum from data taken within the Epoch of Reionisation (EoR) project of the Murchison Widefield Array (MWA). Using data acquired with the Phase II compact array allows a direct bispectrum estimate to be undertaken on the multiple redundantly spaced triangles of antenna tiles, as well as an estimate based on data gridded to the uv-plane. The direct and gridded bispectrum estimators are applied to 21 h of high-band (167–197 MHz; z = 6.2–7.5) data from the 2016 and 2017 observing seasons. Analytic predictions for the bispectrum bias and variance for point-source foregrounds are derived. We compare the output of these approaches, the foreground contribution to the signal, and future prospects for measuring the bispectra with redundant and non-redundant arrays. We find that some triangle configurations yield bispectrum estimates that are consistent with the expected noise level after 10 h, while equilateral configurations are strongly foreground-dominated. Careful choice of triangle configurations may be made to reduce foreground bias that hinders power spectrum estimators, and the 21-cm bispectrum may be accessible in less time than the 21-cm power spectrum for some wave modes, with detections in hundreds of hours.
Geophysical survey and excavations from 2010–2016 at Lawrenz Gun Club (11CS4), a late pre-Columbian village located in the central Illinois River valley in Illinois, identified 10 mounds, a central plaza, and dozens of structures enclosed within a stout 10 hectare bastioned palisade. Nineteen radiocarbon (14C) measurements were taken from single entities of wood charcoal, short-lived plants, and animal bones. A site chronology has been constructed using a Bayesian approach that considers the stratigraphic contexts and feature formation processes. The village was host to hundreds of years of continuous human activity during the Mississippi Period. Mississippian activity at the site is estimated to have begun in cal AD 990–1165 (95% probability), ended in cal AD 1295–1450 (95% probability), and lasted 150–420 yr (95% probability) in the primary Bayesian model with similar results obtained in two alternative models. The palisade is estimated to have been constructed in cal AD 1150–1230 (95% probability) and was continuously repaired and rebuilt for 15–125 yr (95% probability), probably for 40–85 yr (68% probability). Comparison to other studies demonstrates that the bastioned palisade at Lawrenz was one of the earliest constructed in the midcontinental United States.
Retrospective reports of lifetime experience with mental disorders greatly underestimate the actual experiences of disorder because recall error biases reporting of earlier life symptoms downward. This fundamental obstacle to accurate reporting has many adverse consequences for the study and treatment of mental disorders. Better tools for accurate retrospective reporting of mental disorder symptoms have the potential for broad scientific benefits.
We designed a life history calendar (LHC) to support this task, and randomized more than 1000 individuals to each arm of a retrospective diagnostic interview with and without the LHC. We also conducted a careful validation with the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition.
Results demonstrate that—just as with frequent measurement longitudinal studies—use of an LHC in retrospective measurement can more than double reports of lifetime experience of some mental disorders.
The LHC significantly improves retrospective reporting of mental disorders. This tool is practical for application in both large cross-sectional surveys of the general population and clinical intake of new patients.
The fluorescent excitation of long-wavelength X-ray spectra is reviewed with respect to X-ray tube target element, inherent filtration, and optimum kilovoltage. A demountable X-ray tube vacuum spectrograph designed for the determination of the light elements is described. Operation of this instrument with both secondary and combined primary—secondary excitation is evaluated. Examples from the literature are cited to show the feasibility of direct electron excitation of longwavelength spectra.
The purpose of this investigation was to develop a rapid, accurate method of analysis for small amounts of calcium in wolframite concentrates. This analysis is necessary to determine if wolframite concentrates meet the U. S. National Stockpile Specification P-57R2, which limits the calcium content to 0.2 per cent.
Because of the small depth of sample analyzed in fluorescent x-ray spectrography the calcium Kα line intensity was found to be a function of the chemical composition of the calcium-bearing particle as well as the matrix composition. This particle-conn position effect was particularly important in this analysis because the calcium may be present as a carbonate, tungstate, phosphate, etc. Three methods of sample preparation were found to eliminate the variation of calcium Kα intensity with mineralogical occurrences: (1) Reduction in particle size by extensive grinding, (2) chemical fusion wtli sodium carbonate, and (3) solution of the calcium by an add.
Determinations by all three procedures are believed to be accurate to within ± 5 per cent for more than 0.30 per cent calcium and ± 10 per cent at the 0.1-per cent level. The lower limit of detectability is in the order of 0.005-0.01 per cent.
The operating characteristics of a gas-flow proportional counter used in conjunction with a pulse-height analyzer were studied in detail. This detector was found to have a high counting efficiency for calcium Ka radiation, to have a low counting efficiency for overlapping higher order radiation and to have counting stability equivalent to Geiger tubes.
We have been using the technique of pulsed neutron powder diffraction to study several problems in the physics and chemistry of the actinide elements. In these elements one often encounters very complex structures resulting from polymorphic transformations presumably induced by the presence of 5f-electrons. For exampie, at least five distinct structures of plutonium metal are found between room temperature and its melting point of 640°C, and two of the structures are monoclinic! Single crystals are usually not available, and the high resolution which is intrinsic to the time-of-flight powder technique is a powerful tool in the solution of complex structural problems. The relatively low absorption coefficients for neutrons for at least some actinide isotopes is an advantage when surface oxidation is a problem (as in high-temperature experiments) and provides good particle statistics so that high-quality data are available for Rietveld refinement. The low absorption of neutrons by other materials such as vanadium and fused silica enables the use of these materials for the containment of samples in high- and low-temperature environments, and the fixed geometry of the time-of-flight technique simplifies the design of furnaces and cryostats.
We have determined the strain and particle size for several samples of palladium powder by time-of-flight nrutron powder diffraction on two different diffractometers and by x-ray powder diffraction. The results are compared and found to be in fair agreement. The time-of-flight method gives good enough precision to reveal deficiencies in the simple models used for strain and particle size line broadening.
Identifying routes of transmission among hospitalized patients during a healthcare-associated outbreak can be tedious, particularly among patients with complex hospital stays and multiple exposures. Data mining of the electronic health record (EHR) has the potential to rapidly identify common exposures among patients suspected of being part of an outbreak.
We retrospectively analyzed 9 hospital outbreaks that occurred during 2011–2016 and that had previously been characterized both according to transmission route and by molecular characterization of the bacterial isolates. We determined (1) the ability of data mining of the EHR to identify the correct route of transmission, (2) how early the correct route was identified during the timeline of the outbreak, and (3) how many cases in the outbreaks could have been prevented had the system been running in real time.
Correct routes were identified for all outbreaks at the second patient, except for one outbreak involving >1 transmission route that was detected at the eighth patient. Up to 40 or 34 infections (78% or 66% of possible preventable infections, respectively) could have been prevented if data mining had been implemented in real time, assuming the initiation of an effective intervention within 7 or 14 days of identification of the transmission route, respectively.
Data mining of the EHR was accurate for identifying routes of transmission among patients who were part of the outbreak. Prospective validation of this approach using routine whole-genome sequencing and data mining of the EHR for both outbreak detection and route attribution is ongoing.
This replication study examined protective effects of positive childhood memories with caregivers (“angels in the nursery”) against lifespan and intergenerational transmission of trauma. More positive, elaborated angel memories were hypothesized to buffer associations between mothers’ childhood maltreatment and their adulthood posttraumatic stress disorder (PTSD) and depression symptoms, comorbid psychopathology, and children's trauma exposure. Participants were 185 mothers (M age = 30.67 years, SD = 6.44, range = 17–46 years, 54.6% Latina, 17.8% White, 10.3% African American, 17.3% other; 24% Spanish speaking) and children (M age = 42.51 months; SD = 15.95, range = 3–72 months; 51.4% male). Mothers completed the Angels in the Nursery Interview (Van Horn, Lieberman, & Harris, 2008), and assessments of childhood maltreatment, adulthood psychopathology, children's trauma exposure, and demographics. Angel memories significantly moderated associations between maltreatment and PTSD (but not depression) symptoms, comorbid psychopathology, and children's trauma exposure. For mothers with less positive, elaborated angel memories, higher levels of maltreatment predicted higher levels of psychopathology and children's trauma exposure. For mothers with more positive, elaborated memories, however, predictive associations were not significant, reflecting protective effects. Furthermore, protective effects against children's trauma exposure were significant only for female children, suggesting that angel memories may specifically buffer against intergenerational trauma from mothers to daughters.
Radiocarbon (14C or carbon-14, half-life 5730 yr) is a key radionuclide in the assessment of the safety of a geological disposal facility (GDF) for radioactive waste. In particular, the radiological impact of gaseous carbon-14 bearing species has been recognized as a potential issue. Irradiated steels are one of the main sources of carbon-14 in the United Kingdom’s radioactive waste inventory. However, there is considerable uncertainty about the chemical form(s) in which the carbon-14 will be released. The objective of the work was to measure the rate and speciation of carbon-14 release from irradiated 316L(N) stainless steel on leaching under high-pH anoxic conditions, representative of a cement-based near field for low-heat generating wastes. Periodic measurements of carbon-14 releases to both the gas phase and to solution were made in duplicate experiments over a period of up to 417 days. An initial fast release of carbon-14 from the surface of the steel is observed during the first week of leaching, followed by a drop in the rate of release at longer times. Carbon-14 is released primarily to the solution phase with differing fractions released to the gas phase in the two experiments: about 1% of the total release in one and 6% in the other. The predominant dissolved carbon-14 releases are in inorganic form (as 14C-carbonate) but also include organic species. The predominant gas-phase species are hydrocarbons with a smaller fraction of 14CO (which may include some volatile oxygen-containing carbon-species). The experiments are continuing, with final sampling and termination planned after leaching for a total of two years.
Hospital environmental surfaces are frequently contaminated by microorganisms. However, the causal mechanism of bacterial contamination of the environment as a source of transmission is still debated. This prospective study was performed to characterize the nature of multidrug-resistant organism (MDRO) transmission between the environment and patients using standard microbiological and molecular techniques.
Prospective cohort study at 2 academic medical centers.
A prospective multicenter study to characterize the nature of bacterial transfer events between patients and environmental surfaces in rooms that previously housed patients with 1 of 4 ‘marker’ MDROs: methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, Clostridium difficile, and MDR Acinetobacter baumannii. Environmental and patient microbiological samples were obtained on admission into a freshly disinfected inpatient room. Repeat samples from room surfaces and patients were taken on days 3 and 7 and each week the patient stayed in the same room. The bacterial identity, antibiotic susceptibility, and molecular sequences were compared between organisms found in the environment samples and patient sources.
We enrolled 80 patient–room admissions; 9 of these patients (11.3%) were asymptomatically colonized with MDROs at study entry. Hospital room surfaces were contaminated with MDROs despite terminal disinfection in 44 cases (55%). Microbiological Bacterial Transfer events either to the patient, the environment, or both occurred in 12 patient encounters (18.5%) from the microbiologically evaluable cohort.
Microbiological Bacterial Transfer events between patients and the environment were observed in 18.5% of patient encounters and occurred early in the admission. This study suggests that research on prevention methods beyond the standard practice of room disinfection at the end of a patient’s stay is needed to better prevent acquisition of MDROs through the environment.
The Chaudière River region in the Appalachian Mountains of eastern Canada is approximately 700 km north of the southernmost Pleistocene glacial deposits in New York and New Jersey. Detailed compositional analyses of glacial and non-glacial sediments from stratigraphic exposures and more than 40 boreholes drilled to bedrock provide a compositionally constrained record of glacial events, which include deposits of one Marine Oxygen Isotope Stage (MIS) 6 and two post-MIS 5 glaciations. The glacial and associated proglacial deposits rest on compositionally distinctive, preglacial saprolite that is preserved in deeper valleys. These observations constrain interpretations of the glacial/Pleistocene history of the eastern United States and Canada. The fact that there is no unequivocal evidence of pre-MIS 6 till in the Chaudière River region, while there are well-documented pre-MIS 6 glacial deposits south of there and in the American Midwest, also has major climatic implications. The Laurentide Ice Sheet and its ancestors must have been more robust in the west in the early Pleistocene and in the east most recently.
Vitamin B12 is synthesised in the rumen from cobalt (Co) and has a major role in metabolism in the peri-paturient period, although few studies have evaluated the effect of the dietary inclusion of Co, vitamin B12 or injecting vitamin B12 on the metabolism, health and performance of high yielding dairy cows. A total of 56 Holstein-Friesian dairy cows received one of four treatments from 8 weeks before calving to 8 weeks post-calving: C, no added Co; DC, additional 0.2 mg Co/kg dry matter (DM); DB, additional 0.68 mg vitamin B12/kg DM; IB, intra-muscular injection of vitamin B12 to supply 0.71 mg/cow per day prepartum and 1.42 mg/cow per day post-partum. The basal and lactation rations both contained 0.21 mg Co/kg DM. Cows were weighed and condition scored at drying off, 4 weeks before calving, within 24 h of calving and at 2, 4 and 8 weeks post-calving, with blood samples collected at drying off, 2 weeks pre-calving, calving and 2, 4 and 8 weeks post-calving. Liver biopsy samples were collected from all animals at drying off and 4 weeks post-calving. Live weight changed with time, but there was no effect of treatment (P>0.05), whereas cows receiving IB had the lowest mean body condition score and DB the highest (P<0.05). There was no effect of treatment on post-partum DM intake, milk yield or milk fat concentration (P>0.05) with mean values of 21.6 kg/day, 39.6 kg/day and 40.4 g/kg, respectively. Cows receiving IB had a higher plasma vitamin B12 concentration than those receiving any of the other treatments (P<0.001), but there was no effect (P>0.05) of treatment on homocysteine or succinate concentrations, although mean plasma methylmalonic acid concentrations were lower (P=0.019) for cows receiving IB than for Control cows. Plasma β-hydroxybutyrate concentrations increased sharply at calving followed by a decline, but there was no effect of treatment. Similarly, there was no effect (P>0.05) of treatment on plasma non-esterified fatty acids or glucose. Whole tract digestibility of DM and fibre measured at week 7 of lactation were similar between treatments, and there was little effect of treatment on the milk fatty acid profile except for C15:0, which was lower in cows receiving DC than IB (P<0.05). It is concluded that a basal dietary concentration of 0.21 mg Co/kg DM is sufficient to meet the requirements of high yielding dairy cows during the transition period, and there is little benefit from additional Co or vitamin B12.
Externalizing disorders are known to be partly heritable, but the biological pathways linking genetic risk to the manifestation of these costly behaviors remain under investigation. This study sought to identify neural phenotypes associated with genomic vulnerability for externalizing disorders.
One-hundred fifty-five White, non-Hispanic veterans were genotyped using a genome-wide array and underwent resting-state functional magnetic resonance imaging. Genetic susceptibility was assessed using an independently developed polygenic score (PS) for externalizing, and functional neural networks were identified using graph theory based network analysis. Tasks of inhibitory control and psychiatric diagnosis (alcohol/substance use disorders) were used to measure externalizing phenotypes.
A polygenic externalizing disorder score (PS) predicted connectivity in a brain circuit (10 nodes, nine links) centered on left amygdala that included several cortical [bilateral inferior frontal gyrus (IFG) pars triangularis, left rostral anterior cingulate cortex (rACC)] and subcortical (bilateral amygdala, hippocampus, and striatum) regions. Directional analyses revealed that bilateral amygdala influenced left prefrontal cortex (IFG) in participants scoring higher on the externalizing PS, whereas the opposite direction of influence was observed for those scoring lower on the PS. Polygenic variation was also associated with higher Participation Coefficient for bilateral amygdala and left rACC, suggesting that genes related to externalizing modulated the extent to which these nodes functioned as communication hubs.
Findings suggest that externalizing polygenic risk is associated with disrupted connectivity in a neural network implicated in emotion regulation, impulse control, and reinforcement learning. Results provide evidence that this network represents a genetically associated neurobiological vulnerability for externalizing disorders.
The OSU-FEI Electron Microscopy Collaboratory multiplies the number of individuals who can experience hands-on advanced microscopy techniques. The microscopy classroom allows up to 33 attendees to operate, individually and in real time, electron microscopes as if they were sitting in front of the actual instruments. The communications link, a fast backbone augmented by Internet2, allows various microscopes to be operated from the classroom or by collaborators in another city. This system transforms the training of new users from a one-person-at-a-time session with an expert operator to a group collaborative activity that can include users from around the world.