ABSTRACT
Measurements of the one-point probability distribution function and higher-order moments (variance, skewness, and kurtosis) of the high-redshift 21-cm fluctuations are among the most direct ...statistical probes of the non-Gaussian nature of structure formation and evolution during re-ionization. However, contamination from astrophysical foregrounds and instrument systematics pose significant challenges in measuring these statistics in real observations. In this work, we use forward modelling to investigate the feasibility of measuring 21-cm one-point statistics through a foreground avoidance strategy. Leveraging the characteristic wedge-shape of the foregrounds in k-space, we apply a wedge-cut filtre that removes the foreground contaminated modes from a mock data set based on the Hydrogen Epoch of Re-ionization Array (HERA) instrument, and measure the one-point statistics from the image-space representation of the remaining non-contaminated modes. We experiment with varying degrees of wedge-cutting over different frequency bandwidths and find that the centre of the band is the least susceptible to bias from wedge-cutting. Based on this finding, we introduce a rolling filtre method that allows reconstruction of an optimal wedge-cut 21-cm intensity map over the full bandwidth using outputs from wedge-cutting over multiple sub-bands. We perform Monte Carlo simulations to show that HERA should be able to measure the rise in skewness and kurtosis near the end of re-ionization with the rolling wedge-cut method if foreground leakage from the Fourier transform window function can be controlled.
Regurgitative gastroesophageal reflux disease (GERD) refractive to medical treatment is common and caused by mechanical failure of the anti-reflux barrier. We compared the effects of magnetic ...sphincter augmentation (MSA) with those of proton-pump inhibitors (PPIs) in a randomized trial.
Patients with moderate to severe regurgitation (assessed by the foregut symptom questionnaire) despite once-daily PPI therapy (n = 152) were randomly assigned to groups given twice-daily PPIs (n = 102) or laparoscopic MSA (n = 50) at 20 sites, from July 2015 through February 2017. Patients answered questions from the foregut-specific reflux disease questionnaire and GERD health-related quality of life survey about regurgitation, heartburn, dysphagia, bloating, diarrhea, flatulence, and medication use, at baseline and 6 and 12 months after treatment. Six months after PPI therapy, MSA was offered to patients with persistent moderate to severe regurgitation and excess reflux episodes during impedance or pH testing on medication. Regurgitation, foregut scores, esophageal acid exposure, and adverse events were evaluated at 1 year.
Patients in the MSA group and those who crossed over to the MSA group after PPI therapy (n = 75) had similar outcomes. MSA resulted in control of regurgitation in 72/75 patients (96%); regurgitation control was independent of preoperative response to PPIs. Only 8/43 patients receiving PPIs (19%) reported control of regurgitation. Among the 75 patients who received MSA, 61 (81%) had improvements in GERD health-related quality of life improvement scores (greater than 50%) and 68 patients (91%) discontinued daily PPI use. Proportions of patients with dysphagia decreased from 15% to 7% (P < .005), bloating decreased from 55% to 25%, and esophageal acid exposure time decreased from 10.7% to 1.3% (P < .001) from study entry to 1-year after MSA (Combined P < .001). Seventy percent (48/69) of patients had pH normalization at study completion. MSA was not associated with any peri-operative events, device explants, erosions, or migrations.
In a prospective study, we found MSA to reduce regurgitation in 95% of patients with moderate to severe regurgitation despite once-daily PPI therapy. MSA is superior to twice-daily PPIs therapy in reducing regurgitation. Relief of regurgitation is sustained over 12 months. ClinicalTrials.gov no: NCT02505945
Forest restoration projects have become increasingly common around the world and planting trees is almost always a key component. Low seedling survival and growth may result in restoration failures ...and various mechanical site preparation techniques for treatment of soils and vegetation are important tools used to help counteract this. In this article, we synthesize the current state-of-knowledge concerning mechanical site preparation for improved tree establishment when carried out in different forest restoration situations, point out critical research gaps and provide some recommendations for future directions. Mechanical site preparation often results in improved seedling survival and growth. However, if not intensive methods with much soil disturbance are used, it is a rather ineffective tool for controlling competing vegetation. Methods such as scarification, mounding and subsoiling also lead to multiple interactions among soil physical and chemical properties that affect plant survival and growth, and it may be difficult to determine the actual cause–effect relationship of any positive seedling responses. Most research to date on mechanical site preparation and plantation performance has been conducted using a few conifer tree species. Seedling responses differ among tree species and alternative species are often used during restoration compared to production forestry indicating a need for additional research for improved understanding. Several management objectives such as soil protection and increased biodiversity are many times relevant during forest restoration, and mechanical site preparation methods should be implemented carefully because they can have large impacts on the environment.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Observations of the 21 cm Epoch of Reionization signal are dominated by Galactic and extragalactic foregrounds. The need for foreground removal has led to the development of two main techniques, ...often referred to as "foreground avoidance" and "foreground subtraction." Avoidance is associated with filtering foregrounds in Fourier space, while subtraction uses an explicit foreground model that is removed. Using 1088 hr of data from the 64-element PAPER array, we demonstrate that subtraction of a foreground model prior to delay-space foreground filtering results in a modest but measurable improvement of the performance of the filter. This proof-of-concept result shows that improvement stems from the reduced dynamic range requirements needed for the foreground filter: subtraction of a foreground model reduces the total foreground power, so for a fixed dynamic range, the filter can push toward fainter limits. We also find that the choice of window function used in the foreground filter can have an appreciable affect on the performance near the edges of the observing band. We demonstrate these effects using a smaller 3 hr sampling of data from the MWA, and find that the hybrid filtering and subtraction removal approach provides similar improvements across the band as seen in the case with PAPER-64.
GERD patients frequently complain of regurgitation of gastric contents. Medical therapy with proton-pump inhibitors (PPIs) is frequently ineffective in alleviating regurgitation symptoms, because ...PPIs do nothing to restore a weak lower esophageal sphincter. Our aim was to compare effectiveness of increased PPI dosing with laparoscopic magnetic sphincter augmentation (MSA) in patients with moderate-to-severe regurgitation despite once-daily PPI therapy.
One hundred fifty-two patients with GERD, aged ≥21 years with moderate-to-severe regurgitation despite 8 weeks of once-daily PPI therapy, were prospectively enrolled at 21 U.S. sites. Participants were randomized 2:1 to treatment with twice-daily (BID) PPIs (N = 102) or to laparoscopic MSA (N = 50). Standardized foregut symptom questionnaires and ambulatory esophageal reflux monitoring were performed at baseline and at 6 months. Relief of regurgitation, improvement in foregut questionnaire scores, decrease in esophageal acid exposure and reflux events, discontinuation of PPIs, and adverse events were the measures of efficacy.
Per protocol, 89% (42/47) of treated patients with MSA reported relief of regurgitation compared with 10% (10/101) of the BID PPI group (P < .001) at the 6-month primary endpoint. By intention-to-treat analysis, 84% (42/50) of patients in the MSA group and 10% (10/102) in the BID PPI group met this primary endpoint (P < .001). Eighty-one percent (38/47) of patients with MSA versus 8% (7/87) of patients with BID PPI had ≥50% improvement in GERD–health-related quality of life scores (P < .001), and 91% (43/47) remained off of PPI therapy. A normal number of reflux episodes and acid exposures was observed in 91% (40/44) and 89% (39/44) of MSA patients, respectively, compared with 58% (46/79) (P < .001) and 75% (59/79) (P = .065) of BID PPI patients at 6 months. No significant safety issues were observed. In MSA patients, 28% reported transient dysphagia; 4% reported ongoing dysphagia.
Patients with GERD with moderate-to-severe regurgitation, especially despite once-daily PPI treatment, should be considered for minimally invasive treatment with MSA rather than increased PPI therapy. (Clinical trial registration number: NCT02505945.)
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
miRNAs are small noncoding RNAs that may contribute to common diseases through epigenetic regulation of gene expression. Little is known regarding the role of miRNAs in type 2 diabetes (T2D). We ...performed miRNA sequencing and transcriptomic profiling of peripheral monocytes from the longitudinal Multi-Ethnic Study of Atherosclerosis (MESA) (N = 1,154). We examined associations between miRNAs and prevalent impaired fasting glucose and T2D and evaluated the T2D-associated miRNA effect on incident T2D. Of 774 detected miRNAs, 6 (miR-22-3p, miR-33a-5p, miR-181c-5p, miR-92b-3p, miR-222-3p, and miR-944) were associated with prevalent T2D. For five of the six miRNAs (all but miR-222-3p), our findings suggest a dose-response relationship with impaired fasting glucose and T2D. Two of the six miRNAs were associated with incident T2D (miR-92b-3p: hazard ratio HR 1.64, P = 1.30E-03; miR-222-3p: HR 1.97, P = 9.10E-03) in the highest versus lowest tertile of expression. Most of the T2D-associated miRNAs were also associated with HDL cholesterol concentrations. The genes targeted by these miRNAs belong to key nodes of a cholesterol metabolism transcriptomic network. Higher levels of miRNA expression expected to increase intracellular cholesterol accumulation in monocytes are linked to an increase in T2D risk.
ABSTRACT We confirm our recent prediction of the "pitchfork" foreground signature in power spectra of high-redshift 21 cm measurements where the interferometer is sensitive to large-scale structure ...on all baselines. This is due to the inherent response of a wide-field instrument and is characterized by enhanced power from foreground emission in Fourier modes adjacent to those considered to be the most sensitive to the cosmological H i signal. In our recent paper, many signatures from the simulation that predicted this feature were validated against Murchison Widefield Array (MWA) data, but this key pitchfork signature was close to the noise level. In this paper, we improve the data sensitivity through the coherent averaging of 12 independent snapshots with identical instrument settings and provide the first confirmation of the prediction with a signal-to-noise ratio . This wide-field effect can be mitigated by careful antenna designs that suppress sensitivity near the horizon. Simple models for antenna apertures that have been proposed for future instruments such as the Hydrogen Epoch of Reionization Array and the Square Kilometre Array indicate they should suppress foreground leakage from the pitchfork by ∼40 dB relative to the MWA and significantly increase the likelihood of cosmological signal detection in these critical Fourier modes in the three-dimensional power spectrum.
Early sports sampling is associated with superior biomechanics in youth athletes; however, the effect of multisport participation on adult biomechanics is unknown.
To compare jump-landing ...biomechanics between adult recreational athletes who previously participated in 0, 1, or 2 or more select high school varsity sports (VSs; basketball, lacrosse, soccer, volleyball) that feature landing and cutting tasks.
Descriptive laboratory study.
University community setting.
Fifty adult recreational athletes (22 women, 28 men; age = 23.8 ± 2.5 years) with no high school VS experience or with high school VS experience in basketball, lacrosse, soccer, or volleyball. Athletes were grouped into those who participated in 0 (0VS, n = 11), 1 (1VS, n = 21), or 2 or more (2VSs, n = 18) of these sports at the high school level.
The average Landing Error Scoring System (LESS) total score from 3 individual jump landings was determined. A 1-way analysis of covariance using sex as the covariate was calculated to compare groups. The Pearson
was used to test for the correlation between the LESS score and number of sports played, and a linear regression analysis was performed using the number of sports played to predict the LESS score. The α level was set a priori at .05.
The 0VS athletes produced similar LESS scores as the 1VS athletes (5.89 ± 1.2 versus 5.38 ± 1.93 points, respectively,
= .463), whereas the 2VSs athletes demonstrated lower LESS scores (3.56 ± 1.97 points) than the 0VS (
= .002) and 1VS (
= .004) athletes. The LESS scores were moderately negatively correlated with the number of high school VSs played (
= -0.491,
< .001). The linear regression analysis was significant (
= 9.416,
= .004) with
= 0.203. For every additional VS played at the high school level, the LESS score decreased by 1.28 points.
Landing Error Scoring System scores were lower in athletes who had a history of multisport high school varsity participation in basketball, lacrosse, soccer, or volleyball compared with those who had a history of single-sport or no participation in these sports at this level. Multisport high school varsity participation in these sports may result in improved neuromuscular performance and potentially reduced injury risks as adults.
Multiple instruments are pursuing constraints on dark energy, observing reionization and opening a window on the dark ages through the detection and characterization of the 21 cm hydrogen line for ...redshifts ranging from ∼1 to 25. These instruments, including CHIME in the sub-meter and HERA in the meter bands, are wide-field arrays with multiple-degree beams, typically operating in transit mode. Accurate knowledge of their primary beams is critical for separation of bright foregrounds from the desired cosmological signals, but difficult to achieve through astronomical observations alone. Previous beam calibration work at low frequencies has focused on model verification and does not address the need of 21 cm experiments for routine beam mapping, to the horizon, of the as-built array. We describe the design and methodology of a drone-mounted calibrator, the External Calibrator for Hydrogen Observatories (ECHO), that aims to address this need. We report on a first set of trials to calibrate low-frequency dipoles at 137 MHz and compare ECHO measurements to an established beam-mapping system based on transmissions from the Orbcomm satellite constellation. We create beam maps of two dipoles at a 9° resolution and find sample noise ranging from 1% at the zenith to 100% in the far sidelobes. Assuming this sample noise represents the error in the measurement, the higher end of this range is not yet consistent with the desired requirement but is an improvement on Orbcomm. The overall performance of ECHO suggests that the desired precision and angular coverage is achievable in practice with modest improvements. We identify the main sources of systematic error and uncertainty in our measurements and describe the steps needed to overcome them.
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Characterizing the epoch of reionization (EoR) at z ≳ 6 via the redshifted 21 cm line of neutral Hydrogen (H i) is critical to modern astrophysics and cosmology, and thus a key science goal of many ...current and planned low-frequency radio telescopes. The primary challenge to detecting this signal is the overwhelmingly bright foreground emission at these frequencies, placing stringent requirements on the knowledge of the instruments and inaccuracies in analyses. Results from these experiments have largely been limited not by thermal sensitivity but by systematics, particularly caused by the inability to calibrate the instrument to high accuracy. The interferometric bispectrum phase is immune to antenna-based calibration and errors therein, and presents an independent alternative to detect the EoR H i fluctuations while largely avoiding calibration systematics. Here, we provide a demonstration of this technique on a subset of data from the Hydrogen Epoch of Reionization Array (HERA) to place approximate constraints on the brightness temperature of the intergalactic medium (IGM). From this limited data, at z = 7.7 we infer " 1σ" upper limits on the IGM brightness temperature to be ≤ 316 "pseudo" mK at κ∥ = 0.33 "pseudo" h Mpc−1 (data-limited) and ≤ 1000 "pseudo" mK at κ∥ = 0.875 "pseudo" h Mpc−1 (noise-limited). The "pseudo" units denote only an approximate and not an exact correspondence to the actual distance scales and brightness temperatures. By propagating models in parallel to the data analysis, we confirm that the dynamic range required to separate the cosmic H i signal from the foregrounds is similar to that in standard approaches, and the power spectrum of the bispectrum phase is still data-limited (at ≳ 106 dynamic range) indicating scope for further improvement in sensitivity as the array build-out continues.
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