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Patients with anterior cruciate ligament reconstruction (ACLR) are often psychologically and physically under‐prepared for sports participation. This study compared readiness to return to sport based on completion of advanced training after ACLR. Patients with ACLR who self‐selected participation in a 6‐week group‐format advanced training program (TRAINING) were compared to age‐ and sex‐matched patients who did not participate (NoTRAINING). Each group had 23 participants (14 females). Advanced training consisted of plyometric, strengthening, and agility exercises. Baseline and follow‐up testing included psychological measures (Anterior Cruciate Ligament Return to Sport after Injury [ACL‐RSI]; Tampa Scale for Kinesiophobia [TSK‐11]; Knee Activity Self‐Efficacy [KASE]; and fear intensity for the primary fear‐evoking task or situation) and a hop test battery. Return to sport criteria were ACL‐RSI score ≥70 points and limb symmetry index ≥90% on all hop tests. At follow‐up, KASE score was higher in TRAINING than NoTRAINING (92.7 vs. 89.1 points; respectively), but ACL‐RSI, TSK‐11 and fear intensity scores were not significantly different between groups. Return to sport criteria passing rate was not significantly different between groups at baseline (TRAINING: 13%, NoTRAINING: 30%) or follow‐up (TRAINING: 52%, NoTRAINING: 43%); however, the distribution of criteria met at follow‐up differed with more patients in TRAINING than NoTRAINING meeting hop test criteria (30% vs. 4%, respectively) and more patients in NoTRAINING than TRAINING failing to meet any criteria (25% vs. 0%, respectively). Advanced training after ACLR facilitated readiness for sport participation by improving confidence and hop performance, but may not have a preferential effect on fear. [ABSTRACT FROM AUTHOR]

Basal sliding in the ablation zone of the Greenland Ice Sheet is closely associated with water from surface melt introduced to the bed in summer, yet melting of basal ice also generates subglacial water year-round. Assessments of basal melt rely on modeling with results strongly dependent upon assumptions with poor observational constraints. Here we use surface and borehole measurements to investigate the generation and fate of basal meltwater in the ablation zone of Isunnguata Sermia basin, western Greenland. The observational data are used to constrain estimates of the heat and water balances, providing insights into subglacial hydrology during the winter months when surface melt is minimal or nonexistent. Despite relatively slow ice flow speeds during winter, the basal meltwater generation from sliding friction remains manyfold greater than that due to geothermal heat flux. A steady acceleration of ice flow over the winter period at our borehole sites can cause the rate of basal water generation to increase by up to 20 %. Borehole measurements show high but steady basal water pressure rather than monotonically increasing pressure. Ice and groundwater sinks for water do not likely have sufficient capacity to accommodate the meltwater generated in winter. Analysis of basal cavity dynamics suggests that cavity opening associated with flow acceleration likely accommodates only a portion of the basal meltwater, implying that a residual is routed to the terminus through a poorly connected drainage system. A forcing from cavity expansion at high pressure may explain observations of winter acceleration in western Greenland. [ABSTRACT FROM AUTHOR]

We present an electrostatic Particle-In-Cell (PIC) code on multi-block, locally structured, curvilinear meshes called Curvilinear PIC (CPIC). Multi-block meshes are essential to capture complex geometries accurately and with good mesh quality, something that would not be possible with single-block structured meshes that are often used in PIC and for which CPIC was initially developed. Despite the structured nature of the individual blocks, multi-block meshes resemble unstructured meshes in a global sense and introduce several new challenges, such as the presence of discontinuities in the mesh properties and coordinate orientation changes across adjacent blocks, and polyjunction points where an arbitrary number of blocks meet. In CPIC, these challenges have been met by an approach that features: (1) a curvilinear formulation of the PIC method: each mesh block is mapped from the physical space, where the mesh is curvilinear and arbitrarily distorted, to the logical space, where the mesh is uniform and Cartesian on the unit cube; (2) a mimetic discretization of Poisson's equation suitable for multi-block meshes; and (3) a hybrid (logical-space position/physical-space velocity), asynchronous particle mover that mitigates the performance degradation created by the necessity to track particles as they move across blocks. The numerical accuracy of CPIC was verified using two standard plasma–material interaction tests, which demonstrate good agreement with the corresponding analytic solutions. Compared to PIC codes on unstructured meshes, which have also been used for their flexibility in handling complex geometries but whose performance suffers from issues associated with data locality and indirect data access patterns, PIC codes on multi-block structured meshes may offer the best compromise for capturing complex geometries while also maintaining solution accuracy and computational efficiency. [ABSTRACT FROM AUTHOR]

A suite of surface and basal measurements during and after borehole drilling is used to perform in situ investigation of the local basal drainage system and pressure forcing in western Greenland. Drill and borehole water temperature were monitored during borehole drilling, which was performed with dyed hot water. After drilling, borehole water pressure and basal dye concentration were measured concurrently with positions in a GPS strain diamond at the surface. Water pressure exhibited diurnal changes in antiphase with velocity. Dye monitoring in the borehole revealed stagnant basal water for nearly 2 weeks. The interpretation of initial connection to an isolated basal cavity is corroborated by the thermal signature of borehole water during hot water drilling. Measurement-based estimates of cavity size are on the order of cubic meters, and analysis indicates that small changes in its volume could induce the observed pressure variations. It is found that longitudinal coupling effects are unable to force necessary volume changes at the site. Sliding-driven basal cavity opening and elastic uplift from load transfer are plausible mechanisms controlling pressure variations. Elastic uplift requires forcing from a hydraulically connected reach, which observations suggest must be relatively small and in close proximity to the isolated cavity. [ABSTRACT FROM PUBLISHER]

Conformal (or body-fitted) electromagnetic particle-in-cell (EM-PIC) numerical solution schemes are reviewed. Included is a chronological history of relevant particle physics algorithms often employed in these conformal simulations. Brief mathematical descriptions of particle-tracking algorithms and current weighting schemes are provided, along with a brief summary of major time-dependent electromagnetic solution methods. Several research areas are also highlighted for recommended future development of new conformal EM-PIC methods. [ABSTRACT FROM PUBLISHER]

The SPectrometer for Ion DEtermination in fission Research (SPIDER) has been developed for measuring mass yield distributions of fission products from spontaneous and neutron-induced fission. The 2 E –2 v method of measuring the kinetic energy ( E ) and velocity ( v ) of both outgoing fission products has been utilized, with the goal of measuring the mass of the fission products with an average resolution of 1 atomic mass unit (amu). The SPIDER instrument, consisting of detector components for time-of-flight, trajectory, and energy measurements, has been assembled and tested using 229 Th and 252 Cf radioactive decay sources. For commissioning, the fully assembled system measured fission products from spontaneous fission of 252 Cf. Individual measurement resolutions were met for time-of-flight (250 ps FWHM), spacial resolution (2 mm FHWM), and energy (92 keV FWHM for 8.376 MeV). Mass yield results measured from 252 Cf spontaneous fission products are reported from an E – v measurement. [ABSTRACT FROM AUTHOR]

Submammary Device Implantation in Women. Introduction: The frequency of device implantation is increasing in younger patients as our ability to diagnose long-QT syndrome, hypertrophic cardiomyopathy, Brugada Syndrome, and other life-threatening disorders earlier has improved. Similarly, use of cardiac resynchronization therapy and ICD therapies has increased in cardiomyopathy patients. Methods and Results: Device implantation in young women has unique considerations. Standard pectoral implants lead to excessive scar formation due to skin tension and interfere with purse straps, bra straps, and seat belts. There are also privacy and body image concerns as the subclavian region is exposed with many contemporary fashions. Results: Over an 11-year period, we implanted pacemakers, implantable converter-defibrillators (ICDs) and cardiac resynchronization therapy (CRT) devices (defibrillators or pacemakers) in 60 women, aged 13-70 years, using a 2-incision submammary approach. Follow-up surveys were performed using the Florida Patient Acceptance Survey (FPAS). Women with submammary device placement reported significantly greater device acceptance (M = 92.41, SD = 6.46) than women with standard implant technique (M = 70.29, SD = 17.85); t (54) =-6.08, P < 0.001, on the FPAS. Across subscales on the FPAS, women with submammary device placement also reported significantly less body image concern (P < 0.001), less device-related emotional distress (P < 0.001), and greater confidence in returning to life appropriately (P = 0.01) than women with standard device placement. Conclusion: We present here our technique for submammary device implantation. (J Cardiovasc Electrophysiol, Vol. 24, pp. 476-479, April 2013) [ABSTRACT FROM AUTHOR]

Background: Momentum distributions of fragmentation products as a function of fragment mass have been used to study the fragmentation mechanism. The parallel component of the momentum distribution has been well studied previously and modeled. The perpendicular component, however, is much less measured or understood. Purpose: Measure both components of the linear momentum of a wide range of fragmentation products and compare the widths of the momentum distributions to previous results and descriptions. Method: The parallel and perpendicular components of the momentum vector have been measured for projectilelike fragments produced in the reactions of 76Ge with 9Be and 197Au at 130 MeV/nucleon in a magnetic spectrometer. Results: The measured parallel momentum distributions of all fragments follow established systematics. The perpendicular momentum distributions of fragments produced by fragmentation by the 197Au target with masses near that of the projectile exhibit a clear peak near the momentum corresponding to the grazing angle that diminishes with decreasing fragment mass. Conclusions: The interplay between Coulomb and nuclear scattering can be used to describe results for the most peripheral collisions. [ABSTRACT FROM AUTHOR]

A subwavelength aperture-microbolometer sensor was simulated using a finite-difference time domain (FDTD) numerical method. The system consisted of a focusing bullseye grating with a central subwavelength aperture. A thin vanadium oxide sensing layer was suspended behind the aperture for sensing purposes, backed by a thin layer of silicon dioxide. The maximum electric field across the vanadium oxide was measured as a function of incident field. Total noise equivalent power (NEP) was estimated to be 180 pW/√Hz at a frequency of 0.665 THz, comparable to similar current micro sensors. The formation of surface plasmonics greatly increases its sensitivity to particular incident wavelengths. This fact, along with its compact size, make this system a promising candidate for numerous low-cost, small-scale terahertz sensing applications. [ABSTRACT FROM AUTHOR]

The sampling weights and approximate stability criteria for two general fourth-order accurate FDTD schemes were previously derived by Smith et al. However, inconsistencies between several of their governing equations and corresponding solutions were recently discovered. Upon rederiving the full 3-D, fourth-order FDTD dispersion relation, two separate errors were identified in the original work. This paper details these errors and provides corrected sampling weights. Exact stability criteria are also derived and stated for the first time. [ABSTRACT FROM AUTHOR]

Abstract: A scintillator based hodoscope array was recently constructed at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University. The hodoscope will be used to measure the total kinetic energy of fragments in the focal plane of the large S800 magnetic spectrometer at the NSCL to provide atomic charge-state identification. The array consists of 32 closely packed 7.6cm ×7.6cm ×5.1cm CsI(Na) crystals each coupled to a photomultiplier. All of the crystals were characterized with a source prior to installation in the focal plane of the spectrometer. The hodoscope was then tested with a mono-energetic 76Ge primary beam as well as heavy ions from fragmentation reactions. The array is currently in place and has already been used in several recent experiments. The results of characterization of the properties of the crystals are presented here. [Copyright &y& Elsevier]

Permafrost typically exists in regions impacted by past or present glacier and ice sheet coverage. Consequently, the thermal and physical conditions at the bed of ice masses can often form important controls on permafrost and associated groundwater flow dynamics. Here we present a conceptual overview of the Western Greenland ice sheet basal conditions, from ice divide-to-margin, with regards to regional permafrost and groundwater flow fields. Our understanding is based on ice sheet modeling combined with detailed field observations conducted along a 325 km long transect of the ice sheet as part of the "Greenland Analogue Project". We drilled 36 boreholes to the bed of the ice sheet to measure ice temperature, ice deformation and basal sliding, and subglacial water pressure and transmissivity. Simulations incorporate heat transport and higher-order physics for ice flow in three dimensions, data assimilation for constraining model results with climate and surface velocity data fields, and are forced by boundary conditions uniquely constrained by observational data. Our results suggest that between the central ice divide and the ice sheet margin, the bed transitions between four differing thermo-hydrologic regimes. Each zone has different physical conditions and plays contrasting roles in the regional groundwater flow field. We discuss the permafrost conditions beneath the ice sheet and two remaining uncertainties in transitional zones that impact permafrost and groundwater flow conditions. [ABSTRACT FROM AUTHOR]

The intermixed thermal and structural framework of cold firn, water-saturated firn and ice layers in Greenland's percolation zone can be challenging to penetrate with core drills. Here, we present our experiences using a hot water drill for research on the firn layer of the percolation zone. We built and deployed a lightweight and easily transportable system for drilling a transect of ~15 cm diameter boreholes through the full firn column thickness, to depths exceeding 100 m. An instrumented drill stem provides a scientific measurement of the firn properties while drilling. The system was successful at gaining rapid access to the firn column with mixed wet and cold conditions, was easily transported to the site and across the glacier surface, and required a small field crew to operate. The boreholes are well suited for in situ investigations of firn processes in Greenland percolation zone. [ABSTRACT FROM AUTHOR]

One-dimensional simulations of firn evolution neglect horizontal advection from ice flow, which transports the firn column across climate gradients as it is buried by accumulation. Using a suite of model runs, we demonstrate the impacts of horizontal advection on the development of firn density, temperature, and the stratigraphy of melt features through the Greenland ice sheet percolation zone. The simulations isolate processes in synthetic runs and investigate four specific transects and an ice core site. Relative to one-dimensional simulations, the horizontal advection process tends to increase the pore close-off depth, reduce the heat content, and decrease the frequency of melt features with depth by emplacing firn sourced from higher locations under increasingly warm and melt-affected surface conditions. Preservation of the advected pore space and cold content is strongly dependent upon the depth of meltwater infiltration. Horizontal ice flow interacts with topography, climate gradients, and meltwater infiltration to influence the evolution of the firn column structure; the interaction between these variables modulates the impact of horizontal advection on firn at locations around Greenland. Pore close-off and firn temperature are mainly impacted in the lowermost 20–30 km of the percolation zone, which may be relevant to migration of the lower percolation zone. Relatively high in the percolation zone, however, the stratigraphy of melt features can have an advection-derived component that should not be conflated with changing climate. [ABSTRACT FROM AUTHOR]

Abstract When multiple neutrons are emitted in a fission event they are correlated in both energy and their relative angle, which may impact the design of safeguards equipment and other instrumentation for non-proliferation applications. The most recent release of MCNP 6. 2 contains the capability to simulate correlated fission neutrons using the event generators CGMF and FREYA. These radiation transport simulations will be post-processed by the detector response code, DRiFT , and compared directly to correlated fission measurements. DRiFT has been previously compared to single detector measurements, its capabilities have been recently expanded with correlated fission simulations in mind. This paper details updates to DRiFT specific to correlated fission measurements, including tracking source particle energy of all detector events (and non-events), expanded output formats, and digitizer waveform generation. Highlights • MCNP6.2 includes the correlated fission event generators CGMF and FREYA. • MCNP and associated packages DRiFT and MCNPTools are used to simulate scintillator measurements of correlated fission. • DRiFT detector response capabilities have been expanded for correlated fission simulations. • New capabilities in DRiFT include tracking source particle information, expanded output formats and digitizer waveform generation. [ABSTRACT FROM AUTHOR]

The average total kinetic energy (TKE) in Pu239(n,f) has been measured for incident neutron energies between 0.5 and 50 MeV. The experiment was performed at the Los Alamos Neutron Science Center (LANSCE) using the neutron time-of-flight technique, and the kinetic energy of fission fragments post-neutron emission was measured in a double Frisch-gridded ionization chamber. This represents the first experimental study of the energy dependence of TKE in 239Pu above neutron energies of 6 MeV. [ABSTRACT FROM AUTHOR]

Here, we present a compilation of 95 ice temperature profiles from 85 boreholes from the Greenland ice sheet and peripheral ice caps, as well as local ice caps in the Canadian Arctic. Profiles from only 31 boreholes (36 %) were previously available in open-access data repositories. The remaining 54 borehole profiles (64 %) are being made digitally available here for the first time. These newly available profiles, which are associated with pre-2010 boreholes, have been submitted by community members or digitized from published graphics and/or data tables. All 95 profiles are now made available in both absolute (meters) and normalized (0 to 1 ice thickness) depth scales and are accompanied by extensive metadata. These metadata include a transparent description of data provenance. The ice temperature profiles span 70 years, with the earliest profile being from 1950 at Camp VI, West Greenland. To highlight the value of this database in evaluating ice flow simulations, we compare the ice temperature profiles from the Greenland ice sheet with an ice flow simulation by the Parallel Ice Sheet Model (PISM). We find a cold bias in modeled near-surface ice temperatures within the ablation area, a warm bias in modeled basal ice temperatures at inland cold-bedded sites, and an apparent underestimation of deformational heating in high-strain settings. These biases provide process level insight on simulated ice temperatures. [ABSTRACT FROM AUTHOR]

To assess the influence of various heat transfer processes on the thermal structure of near-surface ice in Greenland's ablation zone, we compare in situ measurements with thermal modeling experiments. A total of seven temperature strings were installed at three different field sites, each with between 17 and 32 sensors and extending up to 21m below the ice surface. In one string, temperatures were measured every 30 min, and the record is continuous for more than 3 years. We use these measured ice temperatures to constrain our modeling experiments, focusing on four isolated processes and assessing the relative importance of each for the near-surface ice temperature: (1) the moving boundary of an ablating surface, (2) thermal insulation by snow, (3) radiative energy input, and (4) subsurface ice temperature gradients below the seasonally active near-surface layer. In addition to these four processes, transient heating events were observed in two of the temperature strings. Despite no observations of meltwater pathways to the subsurface, these heating events are likely the refreezing of liquid water below 5-10m of cold ice. Together with subsurface refreezing, the five heat transfer mechanisms presented here account for measured differences of up to 3 °C between the mean annual air temperature and the ice temperature at the depth where annual temperature variability is dissipated. Thus, in Greenland's ablation zone, the mean annual air temperature is not a reliable predictor of the near-surface ice temperature, as is commonly assumed. [ABSTRACT FROM AUTHOR]

We have extended the detector response function toolkit (DRiFT) to provide modeling capabilities of semiconductor sensors. DRiFT provides realistic nuclear instrumentation response by post-processing Monte-Carlo N-particle (MCNP®) radiation transport outputs. MCNP® is capable of modeling radiation transport in complex environments, but has limited detector physics and readout electronics modeling capabilities. Semiconductor detector response can be calculated with a high-fidelity for a flexible range of environments by utilizing MCNP® to simulate radiation interactions inside of detector volumes, and then using DRiFT to model charge transport and signal formation in the semiconductor, as well as the readout electronics. DRiFT models charge transport in the semiconductor, the preamplifier, shaping amplifier, pulse pile-up, and electronic noise to generate detector response. The semiconductor application in DRiFT can model a range of semiconductor materials, shapes, and sizes; and is demonstrated here for a large volume coaxial high-purity germanium (HPGe) detector. Here, we compare detector response functions of a coaxial HPGe detector with measurement of 60Co, 133Ba, and 137Cs at varying count rates, and we conduct a parameter study to demonstrate the effect of changing parameters in the DRiFT simulation. The HPGe detector response function shows excellent agreement with measurements of difference sources with varying dead times and count rates. [ABSTRACT FROM AUTHOR]

An underground nuclear explosion (UNE) couples mechanical energy into crustal rock, which propagates as seismic and acoustic waves. These different physical phenomena transport, by different pathways, to standoff detectors at varying distances. The transport pathways attenuate the original signal but in different ways. Enabled by correct statistical weighting, signal attenuation models can be used to combine these disparate sensor data to estimate the yield of an UNE. Contemporaneous statistical models, used in yield estimation, can be improved with an advanced partition of error for these physical signal propagation models. We present an advanced multivariate approach to error modelling of multiphenomenology physical signatures. In addition to measurement error, our error model represents physical model biases as random with a physics-based covariance structure. To illustrate this proposed framework, we demonstrate the estimation of explosion yield using openly available seismic and acoustic data from chemical single-point explosions. [ABSTRACT FROM AUTHOR]

Temperature sensors installed in a grid of nine full-depth boreholes drilled in the southwestern ablation zone of the Greenland Ice Sheet recorded cooling in discrete sections of ice over time within the lowest third of the ice column in most boreholes. Rates of temperature change outpace cooling expected from vertical conduction alone. Additionally, observed temperature profiles deviate significantly from the site-average thermal profile that is shaped by all thermomechanical processes upstream. These deviations imply recent, localized changes to the basal thermal state in the boreholes. Although numerous heat sources exist to add energy and warm ice as it moves from the central divide towards the margin such as strain heat from internal deformation, latent heat from refreezing meltwater, and the conduction of geothermal heat across the ice–bedrock interface, identifying heat sinks proves more difficult. After eliminating possible mechanisms that could cause cooling, we find that the observed cooling is a manifestation of previous warming in near-basal ice. Thermal decay after latent heat is released from freezing water in basal crevasses is the most likely mechanism resulting in the transient evolution of temperature and the vertical thermal structure observed at our site. We argue basal crevasses are a viable englacial heat source in the basal ice of Greenland's ablation zone and may have a controlling influence on the temperature structure of the near-basal ice. [ABSTRACT FROM AUTHOR]

Deuterated stilbene is an organic scintillator that is a desirable material for fast neutron spectroscopy using spectrum unfolding techniques without requiring time-of-flight information. Due to the crystal structure of the material, some anisotropy of the light output exists, which is dependent on the direction of heavy charged particle recoil relative to the crystal structure. The anisotropy of trans-stilbene (hereafter referred to as stilbene) has been well characterized in previous work, but for deuterated stilbene, the anisotropy has only been partially characterized along the a and b crystal axes, while the artificial c ′ axis, which shows the largest anisotropy in stilbene, has not been characterized until this publication. In this work, two deuterated stilbene crystals were characterized with neutron energies up to 35 MeV at the Los Alamos Neutron Science Center. For one of the crystals, the response is characterized along the a , b , and c ′ axes. This characterization shows a distinct anisotropy along the axes in deuterated stilbene, which is very similar to that found in regular stilbene, such that the a axis is the brightest, while the b and c ′ axes are approximately 3% and 20%–35% lower relative to the a axis. [ABSTRACT FROM AUTHOR]

Abstract Predicting variations in the near-Earth space environment that can lead to spacecraft damage and failure is one example of “space weather” and a big space physics challenge. A project recently funded through the Los Alamos National Laboratory (LANL) Directed Research and Development (LDRD) program aims at developing a new capability to understand, model, and predict Space Hazards Induced near Earth by Large Dynamic Storms, the SHIELDS framework. The project goals are to understand the dynamics of the surface charging environment (SCE), the hot (keV) electrons representing the source and seed populations for the radiation belts, on both macro- and micro-scale. Important physics questions related to particle injection and acceleration associated with magnetospheric storms and substorms, as well as plasma waves, are investigated. These challenging problems are addressed using a team of world-class experts in the fields of space science and computational plasma physics, and state-of-the-art models and computational facilities. A full two-way coupling of physics-based models across multiple scales, including a global MHD (BATS-R-US) embedding a particle-in-cell (iPIC3D) and an inner magnetosphere (RAM-SCB) codes, is achieved. New data assimilation techniques employing in situ satellite data are developed; these provide an order of magnitude improvement in the accuracy in the simulation of the SCE. SHIELDS also includes a post-processing tool designed to calculate the surface charging for specific spacecraft geometry using the Curvilinear Particle-In-Cell (CPIC) code that can be used for reanalysis of satellite failures or for satellite design. Highlights Major highlights from the SHIELDS framework, a new capability to understand, model, and predict Space Hazards Induced near Earth by Large Dynamic Storms, are: • Successful coupling of a global MHD (BATS-R-US) code with a particle-in-cell (iPIC3D) code to resolve reconnection physics. • First data assimilation for RAM-SCB shows significant improvement in simulations of the surface charging environment (SCE). • Effective acceleration of freshly injected electrons by plasma waves at energies as low as ∼50 keV at injection boundaries. • Post-processing tools calculate the surface charging using the CPIC code and evaluate anomalies' relation to SCE dynamics. [ABSTRACT FROM AUTHOR]

Detailed information on the fission process can be inferred from the observation, modeling and theoretical understanding of prompt fission neutron and $ \gamma$ -ray observables. Beyond simple average quantities, the study of distributions and correlations in prompt data, e.g., multiplicity-dependent neutron and $ \gamma$ -ray spectra, angular distributions of the emitted particles, n - n, n - $ \gamma$ , and $ \gamma$ - $ \gamma$ correlations, can place stringent constraints on fission models and parameters that would otherwise be free to be tuned separately to represent individual fission observables. The FREYA and CGMF codes have been developed to follow the sequential emissions of prompt neutrons and $ \gamma$ rays from the initial excited fission fragments produced right after scission. Both codes implement Monte Carlo techniques to sample initial fission fragment configurations in mass, charge and kinetic energy and sample probabilities of neutron and $ \gamma$ emission at each stage of the decay. This approach naturally leads to using simple but powerful statistical techniques to infer distributions and correlations among many observables and model parameters. The comparison of model calculations with experimental data provides a rich arena for testing various nuclear physics models such as those related to the nuclear structure and level densities of neutron-rich nuclei, the $ \gamma$ -ray strength functions of dipole and quadrupole transitions, the mechanism for dividing the excitation energy between the two nascent fragments near scission, and the mechanisms behind the production of angular momentum in the fragments, etc. Beyond the obvious interest from a fundamental physics point of view, such studies are also important for addressing data needs in various nuclear applications. The inclusion of the FREYA and CGMF codes into the MCNP6.2 and MCNPX - PoliMi transport codes, for instance, provides a new and powerful tool to simulate correlated fission events in neutron transport calculations important in nonproliferation, safeguards, nuclear energy, and defense programs. This review provides an overview of the topic, starting from theoretical considerations of the fission process, with a focus on correlated signatures. It then explores the status of experimental correlated fission data and current efforts to address some of the known shortcomings. Numerical simulations employing the FREYA and CGMF codes are compared to experimental data for a wide range of correlated fission quantities. The inclusion of those codes into the MCNP6.2 and MCNPX - PoliMi transport codes is described and discussed in the context of relevant applications. The accuracy of the model predictions and their sensitivity to model assumptions and input parameters are discussed. Finally, a series of important experimental and theoretical questions that remain unanswered are presented, suggesting a renewed effort to address these shortcomings. [ABSTRACT FROM AUTHOR]

Ice in the ablation zone of the Greenland ice sheet is known to contain vertical temperature gradients that arise from conduction at the boundaries, the addition of strain and latent heat, and advective heat transport. A three-dimensional array of temperature measurements in a grid of boreholes reveals horizontal ice temperature gradients that challenge the present conceptualization of heat transfer. We measure two distinct types of temperature variability in the horizontal direction, one impacting a confined region where ice temperatures span a range of 5°C, and another with temperatures consistently varying by approximately 2°C across the entire 3-D block. We suggest the first demonstrates the localized and limited nature of latent heat input, and the second demonstrates that vertical heat advection outpaces diffusion. These findings imply that ice flow is highly variable over sub-ice-thickness length scales, which in turn generates contrasts in ice temperature that may impact ice deformation and fracturing. [ABSTRACT FROM AUTHOR]

A new characterization of the detector response for the EJ301 liquid scintillator based nSpec system has been conducted at the Los Alamos Neutron Science Center. The new characterization was accomplished in two orders of magnitude less time and with better statistics than the previous characterization. The new and old characterization methods were compared by conducting both types of characterization on two detectors (one EJ301 and one EJ301D). The two methods show consistent results and compare well to results previously published in the literature; however, the results from the characterization of the original nSpec detector show discrepancies that have been identified as being caused by oxygen being absorbed into the detector due to a leak. The new characterized detector response shows improved spectrum unfolding performance than the previous characterization. The cross talk of the detector system was also characterized as a function of incident neutron energy and found to have a negligible impact on spectrum unfolding results. Alternative materials (EJ301D and stilbene) were also characterized in a first step towards an upgraded system. The different materials show little difference in unfolding performance, but the comparison is ongoing. A SiPM based stilbene detector was used to evaluate the use of SiPMs in a future system upgrade. The SiPM provides adequate performance, but the custom SiPM readout results in a much longer pulse width than PMT based systems. The measured light output of the SiPM based stilbene compares well with the results in literature. Future work will look at additional materials (deuterated stilbene and organic glass) and optimizing the SiPM readout to decrease the pulse width. [ABSTRACT FROM AUTHOR]

Background: Neutron-rich, even-mass chromium and iron isotopes approaching neutron number N = 40 have been important benchmarks in the development of shell-model effective interactions incorporating the effects of shell evolution in the exotic regime. Odd-mass manganese nuclei have received less attention, but provide important and complementary sensitivity to these interactions. Purpose:We report the observation of two newγ -ray transitions in 63Mn,which establish the (9/2-) and (11/2-) levels on top of the previously known (7/2-) first-excited state. The lifetime for the (7/2-) and (9/2-) excited states were determined for the first time, while an upper limit could be established for the (11/2-) level. Method: Excited states in 63Mn have been populated in inelastic scattering from a 9Be target and in the fragmentation of 65Fe. γγ coincidence relationships were used to establish the decay level scheme. A Doppler line-shape analysis for the Doppler-broadened (7/2-) → 5/2-, (9/2-)→ (7/2-), and (11/2-) → (9/2-) transitions was used to determine (limits for) the corresponding excited-state lifetimes. Results: The low-lying level scheme and the excited-state lifetimes were compared with large-scale shell-model calculations using different model spaces and effective interactions in order to isolate important aspects of shell evolution in this region of structural change. Conclusions: While the theoretical (7/2-) and (9/2-) excitation energies show little dependence on the model space, the calculated lifetime of the (7/2-) level and calculated energy of the (11/2-) level reveal the importance of including the neutron g9/2 and d5/2 orbitals in the model space. The LNPS effective shell-model interaction provides the best overall agreement with the new data. [ABSTRACT FROM AUTHOR]

This report describes a case of an active-can ICD placed in the thigh. A 74-year-old man on chronic renal dialysis had no venous access from cephalic, subclavian, or jugular approaches. Using long active-fixation leads the device was placed from a femoral approach with good sensing, pacing, and defibrillation parameters. (PACE 2003; 26:1297–1298). [ABSTRACT FROM AUTHOR]

Intense rainfall events significantly affect Alpine and Alaskan glaciers through enhanced melting, ice-flow acceleration and subglacial sediment erosion, yet their impact on the Greenland ice sheet has not been assessed. Here we present measurements of ice velocity, subglacial water pressure and meteorological variables from the western margin of the Greenland ice sheet during a week of warm, wet cyclonic weather in late August and early September 2011. We find that extreme surface runoff from melt and rainfall led to a widespread acceleration in ice flow that extended 140 km into the ice-sheet interior. We suggest that the late-season timing was critical in promoting rapid runoff across an extensive bare ice surface that overwhelmed a subglacial hydrological system in transition to a less-efficient winter mode. Reanalysis data reveal that similar cyclonic weather conditions prevailed across southern and western Greenland during this time, and we observe a corresponding ice-flow response at all land- and marine-terminating glaciers in these regions for which data are available. Given that the advection of warm, moist air masses and rainfall over Greenland is expected to become more frequent in the coming decades, our findings portend a previously unforeseen vulnerability of the Greenland ice sheet to climate change. [ABSTRACT FROM AUTHOR]

The 9Be(28Mg,27Na) one-proton removal reaction with a large proton separation energy of Sp(28Mg) = 16.79 MeV is studied at intermediate beam energy. Coincidences of the bound 27Na residues with protons and other light charged particles are measured. These data are analyzed to determine the percentage contributions to the proton removal cross section from the elastic and inelastic nucleón removal mechanisms. These deduced contributions are compared with the eikonal reaction model predictions and with the previously measured data for reactions involving the removal of more weakly bound protons from lighter nuclei. The role of transitions of the proton between different bound single-particle configurations upon the elastic breakup cross section is also quantified in this well-bound case. The measured and calculated elastic breakup fractions are found to be in good agreement. [ABSTRACT FROM AUTHOR]

Abstract: A digital data acquisition system has been combined with a double Frisch gridded ionization chamber for use at both moderated and unmoderated neutron sources at the Los Alamos Neutron Science (LANSCE) facility. The high efficiency of the instrument combined with intense LANSCE beams and new acquisition system permits fission output measurements across 11 orders of magnitude incident neutron energy. The acquisition and analysis system is presented along with the first in-beam performance tests of the setup. [Copyright &y& Elsevier]

A portable neutron spectrometer, nSpec, has been developed for passive interrogation of fast neutrons (> 1 MeV) from neutron sources. The design of the system includes four EJ-301 liquid scintillation cells, a custom stand, and tungsten caps for gamma-ray shielding. Data acquisition settings were optimized to provide a dynamic range of up to 15 MeV neutron energy. The detector response matrix was characterized using a time-of-flight method based on gamma-ray tagged neutron emission from 252Cf. The spectrum unfolding was characterized using measured and simulated spectra of AmBe and 252Cf with the GRAVEL and MLEM methods. Monte Carlo methods were used to examine the uncertainty propagation and determine sufficient counts for a measurement. [ABSTRACT FROM AUTHOR]

We have conducted a series of experiments designed to investigate elastic and electromagnetic (EM) velocity anisotropy associated with a preferentially aligned fracture system on a temperate valley glacier in south-central Alaska, USA. Measurements include a three-dimensional compressional wave (P-wave) seismic reflection survey conducted over a 300m×300m survey patch, with uniform source grid and static checkerboard receiver pattern. Additionally, we acquired a multiazimuth, multi-offset, polarimetric ground-penetrating radar (GPR) reflection experiment in a wagonwheel geometry with 948 of azimuthal coverage. Results show azimuthal variation in the P-wave normal-moveout velocity of >3% (3765 and 3630ms-1 in the fast and slow directions respectively) and difference of nearly 5% between the fast (0.164mns-1) and slow (0.156mns-1) EM velocities. Fracture orientations estimated from the GPR and seismic velocity data are consistent and indicate a preferred fracture orientation that is 30-45° oblique to glacier flow; these measurements agree with borehole observations. Anisotropic analysis of the polarimetric data gives a single volumetric water content estimate of 0.73±0.11%. We conclude that meaningful estimates of physical properties in glaciers based on EM or seismic velocity measurements require collecting data such that the presence of anisotropy can be evaluated and an anisotropic analysis employed when necessary. [ABSTRACT FROM AUTHOR]

We report final-state-exclusive measurements of the light charged fragments in coincidence with 26Ne residual nuclei following the direct two-proton removal from a neutron-rich 28Mg secondary beam. A Dalitz-plot analysis and comparisons with simulations show that a majority of the triple-coincidence events with two protons display phase-space correlations consistent with the (two-body) kinematics of a spatially correlated pair-removal mechanism. The fraction of such correlated events, 56(12)%, is consistent with the fraction of the calculated cross section, 64%, arising from spin S = 0 two-proton configurations in the entrance-channel (shell-model) 28Mg ground state wave function. This result promises access to an additional and more specific probe of the spin and spatial correlations of valence nucleon pairs in exotic nuclei produced as fast secondary beams. [ABSTRACT FROM AUTHOR]

The two-proton removal reaction from 28Mg projectiles has been studied at 93 MeV/u. First coincidence measurements of the heavy 26Ne projectile residues, the removed protons, and other light charged particles enabled the relative cross sections from each of the three possible elastic and inelastic proton removal mechanisms to be determined. These more final-state-exclusive measurements are key for further interrogation of these reaction mechanisms and use of the reaction channel for quantitative spectroscopy of very neutron-rich nuclei. The relative and absolute yields of the three contributing mechanisms are compared to reaction model expectations based on the use of eikonal dynamics and sd-shell-model structure amplitudes. [ABSTRACT FROM AUTHOR]

We present a novel technique for studying the quenching of shell gaps in exotic isotopes. The method is based on extracting Gamow-Teller (&Dgr;L = 0, &Dgr;S = 1) transition strengths [B(GT)] to low-lying states from charge-exchange reactions at intermediate beam energies. These Gamow-Teller strengths are very sensitive to configuration mixing between cross-shell orbitals, and this technique thus provides an important complement to other tools currently used to study cross-shell mixing. This work focuses on the N = 8 shell gap. We populated the ground and 2.24 MeV 0+ states in 12Be using the 12B(1+) (7Li, 7Be) reaction at 80 MeV/u in inverse kinematics. Using the ground-state 5(GT) value from ß-decay measurements (0.184 ± 0.007) as a calibration, the B(GT) for the transition to the second 0+ state was determined to be 0.214 ±0.051. Comparing the extracted Gamow-Teller strengths with shell-model calculations, it was determined that the wave functions of the first and second 0+ states in 12Be are composed of 25 ± 5% and 60 ± 5% (0s)4(0p)8 configurations, respectively. [ABSTRACT FROM AUTHOR]

Measurements and reaction model calculations are reported for single-neutron pickup reactions onto a fast 22Mg secondary beam at 84 MeV per nucleon. Measurements made on both carbon and beryllium targets, having very different structures, were used to investigate the likely nature of the pickup reaction mechanism. The measurements involve thick reaction targets and γ-ray spectroscopy of the projectile-like reaction residue for final-state resolution, which permit experiments with low incident beam rates compared to traditional low-energy transfer reactions. From measured longitudinal momentum distributions we show that the 12C(22Mg,23Mg+γ)X reaction largely proceeds as a direct two-body reaction, with the neutron transfer producing bound 11C target residues. The corresponding reaction on the 9Be target seems to largely leave the 8Be residual nucleus unbound at excitation energies high in the continuum. We discuss the possible use of such fast-beam one-neutron pickup reactions to track single-particle strength in exotic nuclei and also their expected sensitivity to neutron high-ℓ (intruder) states, which are often direct indicators of shell evolution and the disappearance of magic numbers in the exotic regime. [ABSTRACT FROM AUTHOR]

Water plays a first-order role in basal sliding of glaciers and ice sheets and is often a key constituent of accelerated glacier motion. Subglacial water is known to occupy systems of cavities and conduits at the interface between ice and the underlying bed surface, depending upon the history of water input and the characteristics of the substrate. Full understanding of the extent and configuration of basal water is lacking, however, because direct observation is difficult. This limits our ability to simulate ice dynamics and the subsequent impacts on sea-level rise realistically. Here we show that the subglacial hydrological system can have a large volume of water occupying basal crevasses that extend upward from the bed into the overlying ice. Radar and seismic imaging combined with in situ borehole measurements collected on Bench Glacier, Alaska, reveal numerous water-filled basal crevasses with highly transmissive connections to the bed. Some crevasses extend many tens of metres above the bed and together they hold a volume of water equivalent to at least a decimetre layer covering the bed. Our results demonstrate that the basal hydrologic system can extend high into the overlying ice mass, where basal crevasses increase water-storage capacity and could potentially modulate basal water pressure. Because basal crevasses can form under commonly observed glaciological conditions, our findings have implications for interpreting and modelling subglacial hydrologic processes and related sliding accelerations of glaciers and ice sheets. [ABSTRACT FROM AUTHOR]

Device placement in women has unique considerations not addressed with standard implant techniques. These may include irritation and discomfort from purse and/or bra straps, changes in body image, and cosmetic issues with visible scars. Submammary device placement (SMI) addresses these problems and may be associated with greater patient comfort, cosmesis, and device acceptance. Over a 9-year period, 51 women, mean age 47 years (range 13-70 years), underwent submammary device implantation at our institution. These included seven cardiac resynchronization therapy devices, 26 implantable cardioverter defibrillators, and 18 pacemakers. Devices had been implanted for a mean of 57 months (range 2-118 months) when, in 2009, patient satisfaction was assessed via a telephone survey. Questions related to the initial decision, the preprocedure education, implant experience, recovery, complications, and long-term satisfaction. Seventy-three percent of women listed cosmesis as their main reason for SMI, 76% had a mammogram since implant, and 89% reported no issues with mammography. Ninety-seven percent felt that SMI was the right choice and 95% stated they would do SMI again. Ninety-five percent also said they would recommend the procedure to others. Complications were rare (three lead dislodgements and one pneumothorax). SMI has high patient acceptance and long-term satisfaction with few complications. This procedure should be considered in women requiring device implantation. (PACE 2010; 1373-1375) [ABSTRACT FROM AUTHOR]

Device placement in women has unique considerations not addressed with standard implant techniques. These may include irritation and discomfort from purse and/or bra straps, changes in body image, and cosmetic issues with visible scars. Submammary device placement (SMI) addresses these problems and may be associated with greater patient comfort, cosmesis, and device acceptance. Over a 9-year period, 51 women, mean age 47 years (range 13-70 years), underwent submammary device implantation at our institution. These included seven cardiac resynchronization therapy devices, 26 implantable cardioverter defibrillators, and 18 pacemakers. Devices had been implanted for a mean of 57 months (range 2-118 months) when, in 2009, patient satisfaction was assessed via a telephone survey. Questions related to the initial decision, the preprocedure education, implant experience, recovery, complications, and long-term satisfaction. Seventy-three percent of women listed cosmesis as their main reason for SMI, 76% had a mammogram since implant, and 89% reported no issues with mammography. Ninety-seven percent felt that SMI was the right choice and 95% stated they would do SMI again. Ninety-five percent also said they would recommend the procedure to others. Complications were rare (three lead dislodgements and one pneumothorax). SMI has high patient acceptance and long-term satisfaction with few complications. This procedure should be considered in women requiring device implantation. (PACE 2010; 1373-1375) [ABSTRACT FROM AUTHOR]