The Askaryan Radio Array (ARA) is an ultrahigh energy (UHE, > 1017 eV) neutrino detector designed to observe neutrinos by searching for the radio waves emitted by the relativistic products of ...neutrino-nucleon interactions in Antarctic ice. In this paper, we present constraints on the diffuse flux of ultrahigh energy neutrinos between 1016 and 1021 eV resulting from a search for neutrinos in two complementary analyses, both analyzing four years of data (2013–2016) from the two deep stations (A2, A3) operating at that time. We place a 90% CL upper limit on the diffuse all flavor neutrino flux at 1018 eV of EF(E) = 5.6 × 10−16 cm−2 s−1 sr−1. This analysis includes four times the exposure of the previous ARA result and represents approximately 1 / 5 th the exposure expected from operating ARA until the end of 2022.
Topological defects can markedly alter nanomaterial properties. This presents opportunities for "defect engineering," where desired functionalities are generated through defect manipulation. However, ...imaging defects in working devices with nanoscale resolution remains elusive. We report three-dimensional imaging of dislocation dynamics in individual battery cathode nanoparticles under operando conditions using Bragg coherent diffractive imaging. Dislocations are static at room temperature and mobile during charge transport. During the structural phase transformation, the lithium-rich phase nucleates near the dislocation and spreads inhomogeneously. The dislocation field is a local probe of elastic properties, and we find that a region of the material exhibits a negative Poisson's ratio at high voltage. Operando dislocation imaging thus opens a powerful avenue for facilitating improvement and rational design of nanostructured materials.
Ultra-high energy neutrinos are detectable through impulsive radio signals generated through interactions in dense media, such as ice. Subsurface in-ice radio arrays are a promising way to advance ...the observation and measurement of astrophysical high-energy neutrinos with energies above those discovered by the IceCube detector (≥ 1 PeV) as well as cosmogenic neutrinos created in the GZK process (≥ 100 PeV). Here we describe the NuPhase detector, which is a compact receiving array of low-gain antennas deployed 185 m deep in glacial ice near the South Pole. Signals from the antennas are digitized and coherently summed into multiple beams to form a low-threshold interferometric phased array trigger for radio impulses. The NuPhase detector was installed at an Askaryan Radio Array (ARA) station during the 2017/18 Austral summer season. In situ measurements with an impulsive, point-source calibration instrument show a 50% trigger efficiency on impulses with voltage signal-to-noise ratios (SNR) of ≤2.0, a factor of ∼1.8 improvement in SNR over the standard ARA combinatoric trigger. Hardware-level simulations, validated with in situ measurements, predict a trigger threshold of an SNR as low as 1.6 for neutrino interactions that are in the far field of the array. With the already-achieved NuPhase trigger performance included in ARASim, a detector simulation for the ARA experiment, we find the trigger-level effective detector volume is increased by a factor of 1.8 at neutrino energies between 10 and 100 PeV compared to the currently used ARA combinatoric trigger. We also discuss an achievable near term path toward lowering the trigger threshold further to an SNR of 1.0, which would increase the effective single-station volume by more than a factor of 3 in the same range of neutrino energies.
We present simultaneous observations of aurorae at Jupiter from the Hubble Space Telescope and Hisaki, in combination with the in situ measurements of magnetic field, particles, and radio waves from ...the Juno Spacecraft in the outer magnetosphere, from ~ 80RJ to 60RJ during 17 to 22 March 2017. Two cycles of accumulation and release of magnetic flux, named magnetic loading/unloading, were identified during this period, which correlate well with electron energization and auroral intensifications. Magnetic reconnection events are identified during both the loading and unloading periods, indicating that reconnection and unloading are independent processes. These results show that the dynamics in the middle magnetosphere are coupled with auroral variability.
Key Points
Accumulation and release of magnetic flux in the middle Jovian magnetosphere modulate auroral intensifications
Magnetic reconnection process occurs independently of Jupiter's global loading and unloading of magnetic flux
We provide direct evidence that unloading of magnetic flux causes enhancements of auroral kilometric emissions
Ethical competence, which is reflected in the ability to detect ethical challenges in clinical situations and engage in deliberate thinking on ethical actions, is one of the core competencies of ...nursing practice.
The purpose of this study was to develop and implement an interactive situational e-learning system, integrating nursing ethical decisions into a nursing ethics course, and to evaluate the effects of this course on student nurses' ethical decision-making competence.
The project was designed to be carried out in two phases. In the first phase, an interactive situated e-learning system was developed and integrated into the nursing ethics course. The second phase involved implementing the course and evaluating its effects in a quasi-experimental study. The course intervention was designed for 2h per week over one semester (18weeks).
A total of 100 two-year technical college nursing students in their second year of the program participated in the study, with 51 in the experimental group and 49 in the control group.
After completing the course, the students in the experimental group showed significant improvement in nursing ethical decision-making competence, including skills in “raising questions,” “recognizing differences,” “comparing differences,” “self-dialogue,” “taking action,” and “identifying the implications of decisions made,” compared to their performance prior to the class. After controlling for factors influencing learning effects, students in the experimental group showed superiority to those in the control group in the competency of “recognizing differences.” The students in the experimental group reported that the course pushed them to search for and collect information needed to resolve the ethical dilemma.
The interactive situational e-learning system developed by our project was helpful in developing the students' competence in ethical reasoning. The e-learning system and the situational teaching materials used in this study may be applicable in nursing and related professional ethics courses.
•The interactive situational e-learning system provides a learning environment for enhancing nursing student's competence in ethical reasoning.•The e-learning program promotes students' abilities to reflect on ethical issues.•The course design provides a model for integrating e-learning technology into a nursing ethics course.
ABSTRACT
The Nearby Evolved Stars Survey (NESS) is a volume-complete sample of ∼850 Galactic evolved stars within 3 kpc at (sub-)mm wavelengths, observed in the CO J = (2–1) and (3–2) rotational ...lines, and the sub-mm continuum, using the James Clark Maxwell Telescope and Atacama Pathfinder Experiment. NESS consists of five tiers, based on distances and dust-production rate (DPR). We define a new metric for estimating the distances to evolved stars and compare its results to Gaia EDR3. Replicating other studies, the most-evolved, highly enshrouded objects in the Galactic Plane dominate the dust returned by our sources, and we initially estimate a total DPR of 4.7 × 10−5 M⊙ yr−1 from our sample. Our sub-mm fluxes are systematically higher and spectral indices are typically shallower than dust models typically predict. The 450/850 $\mu$m spectral indices are consistent with the blackbody Rayleigh–Jeans regime, suggesting a large fraction of evolved stars have unexpectedly large envelopes of cold dust.
Background
Oesophageal diverticula are rare outpouchings of the oesophagus which may be classified anatomically as pharyngeal (Zenker’s), mid-oesophageal and epiphrenic. While surgery is indicated ...for symptomatic patients, no consensus exists regarding the optimum technique for non-Zenker’s oesophageal diverticula. The aim of this study was to determine the outcome of surgery in patients with non-Zenker’s oesophageal diverticula.
Methods
PubMed, MEDLINE and the Cochrane Library (January 1990 to January 2016) were searched for studies which reported outcomes of surgery in patients with non-Zenker’s oesophageal diverticula. Primary outcome measure was the rate of staple line leakage.
Results
Twenty-five observational studies involving 511 patients (259 male, median age 62 years) with mid-oesophageal (
n
= 53) and epiphrenic oesophageal (
n
= 458) diverticula who had undergone surgery thoracotomy (
n
= 252), laparoscopy (
n
= 204), thoracoscopy (
n
= 42), laparotomy (
n
= 5), combined laparoscopy and thoracoscopy (
n
= 8) were analysed. Myotomy was performed in 437 patients (85.5%), and anti-reflux procedures were performed in 342 patients (69.5%). Overall pooled staple line leak rates were reported in 13.3% 95% c.i. (11.0–15.7),
p
< 0.001 and were less common after myotomy (12.4%) compared with no myotomy (26.1%,
p
= 0.002).
Conclusions
No consensus exists regarding the surgical treatment of non-Zenker’s oesophageal diverticula, but staple line leakage is common and is reduced significantly by myotomy.
Abstract
The Superpressure Balloon-borne Imaging Telescope (
SuperBIT
) is a diffraction-limited, wide-field, 0.5 m, near-infrared to near-ultraviolet observatory designed to exploit the ...stratosphere’s space-like conditions.
SuperBIT
’s 2023 science flight will deliver deep, blue imaging of galaxy clusters for gravitational lensing analysis. In preparation, we have developed a weak-lensing measurement pipeline with modern algorithms for PSF characterization, shape measurement, and shear calibration. We validate our pipeline and forecast
SuperBIT
survey properties with simulated galaxy cluster observations in
SuperBIT
’s near-UV and blue bandpasses. We predict imaging depth, galaxy number (source) density, and redshift distribution for observations in
SuperBIT
’s three bluest filters; the effect of lensing sample selections is also considered. We find that, in three hours of on-sky integration,
SuperBIT
can attain a depth of
b
= 26 mag and a total source density exceeding 40 galaxies per square arcminute. Even with the application of lensing-analysis catalog selections, we find
b
-band source densities between 25 and 30 galaxies per square arcminute with a median redshift of
z
= 1.1. Our analysis confirms
SuperBIT
’s capability for weak gravitational lensing measurements in the blue.
State-of-the-art silicon interposer technology of chip-on-wafer-on-substrate (CoWoS) containing the second-generation high bandwidth memory (HBM) has been applied for the first time in fabricating ...high-performance wafer-level system-in-package. An ultralarge Si interposer up to 1200 mm 2 made by a two-mask stitching process is used to form the basis of the second-generation CoWoS (CoWoS-2) to accommodate chips of logic and memory and achieve the highest possible performance. Yield challenges associated with the high warpage of such a large heterogeneous system are resolved to achieve high package yield. Compared to alternative interposer integration approaches such as chip-on-substrate, CoWoS offers more competitive design rule which results in better power consumption, transmission loss, and eye diagram. CoWoS-2 has positioned itself as a flexible 3-D IC platform for logic-memory heterogeneous integration between logic system-on-chip and HBM for various high-performance computing applications.
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