Search

To evaluate the usefulness of a published clinical decision support tool to predict the likelihood of a retrievable inferior vena cava (IVC) filter being maintained as a permanent device.This multicenter retrospective cohort study included 1498 consecutive patients (852 men and 646 women; median age, 60 years; range, 18-98 years) who underwent retrievable IVC filter insertion between January 2012 and December 2019. The indications for IVC filtration, baseline neurologic disease, history of venous thromboembolism (VTE), and underlying malignancy were recorded. Accuracy, sensitivity, and specificity of a published clinical support tool were calculated to determine the usefulness of the tool.The majority of filters (1271/1498 [85%]) were placed for VTE with a contraindication to anticoagulation. A history of VTE was present in 811 of 1498 patients (54%) patients; underlying malignancy in 531 of 1498 patients (35%), and neurological disease in 258 of 1498 patients (17%). Of the 1498 filters, 456 (30%) were retrieved, 276 (18%) were maintained as permanent devices on follow-up, and 766 (51%) filters were not retrieved. The accuracy of the clinical prediction model was 61%, sensitivity was 60%, and specificity was 62%.A previously published clinical decision support tool to predict permanence of IVC filters had modest usefulness in the examined population; this factor should be taken into account when using this clinical decision support tool outside of the original study population. Future studies are required to refine the predictive capability of IVC filter decision support tools for broader use across different patient populations.

Recreational fishing is a commonplace leisure activity within the developed world but can generate tension when activities conflict with conservation agendas. A potential conflict arises over the use of European river lamprey, Lampetra fluviatilis (L.), a protected species, by UK coarse (freshwater non-salmonid) predator anglers. This study used geographically stratified interviews with 69 predator anglers to explore attitudes towards the use of lamprey as bait, their conservation status and knowledge of biosecurity regulations. Most participants used lamprey as bait to some degree and agreed that, if threatened by exploitation, a ban on their use as angling bait should be implemented. Ordinal regression analysis indicated the presence of a subset of anglers who value lamprey as bait more than others and may oppose conservation efforts. The benefits of the potential establishment of bait certification schemes are also considered.

After decades of research, recent laser-driven inertial fusion experiments have demonstrated rapid progress toward achieving thermonuclear ignition using capsule designs with cryogenic fuel layers. The ignition physics for these layered capsules involves a complex interplay between the dynamically forming hot spot and the dense surrounding fuel. Using analytic theory and numerical simulations, we demonstrate that the mass ablation rate into the hot spot depends sensitively upon the temperature of the dense fuel, resulting in ablative inflows up to ~4x faster than previous estimates. This produces an enthalpy flux into the hot spot that plays a critical role in controlling the hot spot temperature, the ignition threshold, and the subsequent burn propagation. The net influence of mass ablation on the ignition threshold is regulated by a dimensionless parameter that depends upon the temperature of the dense fuel. As a consequence, the ignition threshold is sensitive to any mechanism that heats the dense fuel, such as neutrons or radiation emitted from the hot spot. These predictions are confirmed using radiation hydrodynamic simulations for a series of capsules near ignition conditions. This analysis may have relevance for understanding the variable performance of recent experiments and for guiding new capsule designs toward higher fusion yields., Comment: 12 pages, 9 figures

Objective:Time-out is a widely used child discipline strategy and one of the only strategies currently recommended by the American Academy of Pediatrics. Despite its widespread use and significant evidence to support its effectiveness in decreasing problem behavior, time-out is often sugges

Many rivers are heavily fragmented, resulting from anthropogenic cross‐channel structures. Cost‐effective solutions are needed to restore habitat connectivity for migratory fishes, including those of conservation concern, such as the European river lamprey (Lampetra fluviatilis). Studded material is becoming increasingly used as a low‐cost retrofit solution for lamprey passage at sloping weirs, although little is known about the efficacy of the material or what stud arrangements may be most effective. This study tested whether expanding a single‐density studded tile (SDT) lane from 1 to 2‐m width increased passage success (nreleased = 133), and also compared the passage performance between a SDT lane and a dual‐density studded tile (DDT) lane (nreleased = 115) at a sloping weir, using PIT telemetry. No passage was recorded (nattempted = 89) at the 2‐m wide SDT lane, but 61.6% (npassed/attempted = 53/86) passed using DDT/SDT lane combination. However, increased passage efficiency was likely a result of high river flow (Q2.0‐Q30.6) during DDT/SDT comparison versus low (Q8.3‐Q88.5) while the 2‐m wide SDT lane was employed. There was no evidence that passage occurred using solely one stud configuration. It is, therefore, hypothesised that passage of river lamprey at weirs is more dependent on flow regime than the provision of either stud configuration. However, with 46.1% (npassed/released = 53/115) of those released during DDT/SDT comparison passing on the instrumented section (10.5% of weir face), the provision of studded tiles may aid in lamprey passage at high flows, presumably as the tiles generate a low‐velocity boundary layer that can be utilised as lamprey swim above the studs.

Ensemble based data assimilation approaches, such as the Ensemble Kalman Filter (EnKF), have been widely and successfully implemented to combine observations with dynamic forecast models. In this study the EnKF is adapted to assimilate ground deformation observations from interferometric synthetic-aperture radar (InSAR) and GPS into thermomechanical finite element models (FEM) to evaluate volcanic unrest. Two eruption hindcasts are investigated: the 2008 eruption of Okmok volcano, Alaska and the 2018 eruption of Sierra Negra volcano, Galapagos, Ecuador. At Okmok, EnKF forecasts tensile failure and the lateral movement of the magma from a central pressure source in the lead up to its 2008 eruption indicating potential for diking. Alternatively, at Sierra Negra, the EnKF forecasts significant shear failure coincident with a Mw 5.4 earthquake that preceded the 2018 eruption. These successful hindcasts highlight the flexibility and potential of the volcano EnKF approach for near real time monitoring and hazard assessment at active volcanoes worldwide.

In this study, synthetic numerical experiments are conducted to investigate how well the Ensemble Kalman Filter (EnKF) data assimilation approach distinguishes between two potential drivers of ground deformation at volcanic systems: pressurization and lateral reservoir expansion. Numerical models indicate that pressure-driven inflation creates larger radial displacements relative to inflation driven by lateral expansion. However, the introduction of noise can obscure these differences in simulated geodetic data. Although the EnKF does not fully reproduce the original synthetic models, it remains sensitive to changes in the magma reservoir's aspect ratio and is able to distinguish between the two inflation mechanisms. Ultimately, there remains significant non-uniqueness in how changes in reservoir pressure and size are reflected in surface deformation for any given aspect ratio, but future innovations may continue to improve filter performance.

In recent years, the advent of ensemble-based methods in volcanology has greatly facilitated the use of numerical models within data assimilation frameworks that had previously been limited, either computationally or mathematically, to simpler analytical models. Because numerical models can simulate stress conditions throughout the model space, recent inversions based on assimilated volcanic deformation data are able to track not only the basic parameters of a magma reservoir, but also how those parameters affect the overall mechanical stability of the system. Although this approach has produced successful forecasts and hind-casts of volcanic eruptions, much work remains to be done in assessing its full capabilities and limitations. In particular, non-uniqueness in how source parameters are reflected in surface deformation can significantly impair the inversion’s ability to resolve the magma system’s true state and, by extension, the likelihood of eruption. While this problem is nearly intractable for deep reservoirs, for which changes in pressure and size are indistinguishable from deformation alone, preliminary synthetic tests at shallower systems have demonstrated a limited ability to resolve the main inflation mechanism. In this study, we investigate how the performance of an Ensemble Kalman Filter (EnKF) data assimilation framework varies under a wider range of experimental conditions than used in these initial investigations. In particular, we test how different mathematical implementations of the filter and how different levels of data availability affect the EnKF’s ability to distinguish inflation drivers and to accurately resolve reservoir parameters. To implement this experiment, two time series of synthetic GPS and InSAR data are generated, one in which deformation is driven by excess pressure and another in which it is driven by lateral expansion of the reservoir. For each filter implementation these datasets are down-sampled and given random noise prior to inversion, and after assimilation the resulting model is compared to the original synthetic conditions. We find that newer deterministic formulations of the EnKF are more accurate and consistent than the original stochastic implementation, although the improvement is relatively small. Moreover, some amount of parameter inflation is required to avoid model collapse, but more sophisticated adaptive inflation schemes do not produce better results than more basic formulations. Finally, we show that while increased data sampling does improve performance, this effect is subject to diminishing returns. In particular, data resolution near the center of inflation is more important than overall range of coverage. As new inversion techniques are developed or adapted from other fields, rigorous testing as demonstrated here will be a key step in being able to interpret future results and develop new forecasting frameworks for volcanic eruptions.

The ability to recall the temporal order of events develops much more slowly than the ability to recall facts about events. To explore what processes facilitate memory for temporal information, we tested 3- to 6-year-old children (

Results are presented from a series of simulations examining the susceptibility of the cross-beam energy transfer (CBET) instability to nonlinear processes in the context of direct-drive inertial confinement fusion experiments on the OMEGA laser facility. These form the basis for the second paper of this series [A. G. Seaton, L. Yin, R. Follett, B. J. Albright, and A. Le, “Cross-beam energy transfer in direct-drive ICF. II. Theory and simulation of mitigation through increased laser bandwidth,” Phys. Plasmas 29, 042707 (2022)], where we examine the efficacy of increases in laser bandwidth at suppressing CBET. We choose laser and plasma conditions for the simulations that are favorable to CBET and promote nonlinearity. Through a comparison of outputs from the particle-in-cell code vector particle in cell (VPIC) and the linearized fluid code laser-plasma simulation environment (LPSE), a series of nonlinear effects have been identified in the kinetic simulations that include particle trapping, the two-ion wave decay, and ion-acoustic wave self-focusing. These effects produce time-dependent energy transfer, in contrast to the linearized fluid simulations in which a steady state is reached after an initial transient. Ion trapping is shown to allow for increased energy transfer relative to fluid simulations, with the remaining nonlinear processes acting to reduce the energy transfer. Nonlinear dynamics is contrasted for low- and high-intensity beams as well as between speckled and planar beams. For the parameters under consideration, beam profile has a significant effect on nonlinear dynamics, though the greatest sensitivity is to beam intensity.

The response of the cross-beam energy transfer instability (CBET) to laser bandwidth is investigated through a combination of theory and simulation. Existing linear theory is generalized to treat broadband lasers, demonstrating that CBET is most effectively suppressed when the bandwidth exceeds the ion-acoustic wave (IAW) frequency. It is shown that for such bandwidths, reverse (seed to pump) transfer becomes possible, which reduces the net energy transfer rapidly as bandwidth is increased. The CBET gain exponent in this regime scales with bandwidth ([Formula: see text]) as [Formula: see text] for Gaussian or Lorentzian laser spectra with different scalings possible for other spectra. Comparison of our theory with linearized fluid and particle-in-cell simulations, performed with the laser-plasma simulation environment (LPSE) and vector particle in cell (VPIC) codes, respectively, finds that the model is accurate in the absence of nonlinear processes. However, linear analysis also finds that the IAW energy density scales as [Formula: see text], implying that nonlinear effects may be more difficult to control than the CBET scaling would suggest. Indeed, nonlinear effects are found to be present in VPIC simulations with high-intensity lasers, despite minimal apparent CBET. Nonlinear processes in the VPIC cases include particle trapping, the two-ion wave decay, and ion wave self-focusing. In some high intensity VPIC cases, these effects lead to net energy transfer from seed to pump and increases to backscatter stimulated Brillouin scattering reflectivities. Finally, for a given bandwidth, we show that improved control of nonlinear processes can be achieved via smoothing by spectral dispersion.

High-yield implosions on the National Ignition Facility rely on maintaining low entropy in the deuterium–tritium fuel, quantified by its adiabat, in order to efficiently couple energy to the hot spot through high compression of the fuel layer. We present very-high-resolution xRAGE simulation results that study the impacts of interfacial mixing and the jetting of materials due to surface defects, defects on internal interfaces, voids, and engineering features on fuel layer compression. Defects and voids are typically neglected in implosion simulations due to their small size and three-dimensional geometry. Our results showed that supersonic jets of material arise through weak spots in the shell at peak implosion velocity that prevent uniform compression of the fuel layer even when they do not introduce contaminant into the hot spot. This occurs despite maintaining low fuel entropy, since the formation of the weak spots involves nonradial displacement of fuel mass. In contrast, simulations show that fuel–ablator mixing due to interfacial instabilities has a much smaller impact on compression. We show that defects on interior interfaces of plastic capsules decrease compression by 15% to 25% and interfacial mixing between the ablator and fuel decreases compression by less than 1% for implosions with plastic or high-density carbon (HDC) ablators. For low adiabat implosions, the impact of jetting seeded by the support tent can also decrease the compression by 25%. We demonstrate that the inclusion of interior defects in simulations can explain the inferred compression in two fielded plastic capsule implosions and that the inclusion of voids, for which available characterization has large uncertainties, in simulations of HDC capsule implosions has a qualitatively consistent impact. This mechanism offers a potential explanation for persistently overestimated fuel compression in design simulations of layered implosions on the National Ignition Facility.

Cross-beam energy transfer (CBET) was measured in two regimes where the energy transfer saturation mechanism was determined by the plasma and laser beam conditions. Linear kinetic CBET theory agrees well with the measured energy transfer in all experimental configurations and at all probe beam intensities when accounting for pump depletion and the plasma conditions measured using Thomson-scattering. Simultaneous CBET and Thomson-scattering measurements enabled uncertainties in the plasma conditions to be isolated from CBET theory, which allowed the saturation mechanisms to be identified. In the perpendicular-beam configuration the saturation mode was through ion heating, which resulted from ion trapping in the driven waves and subsequent ion-ion collisional heating. In the co-propagating beam configuration there was minimal ion heating and the saturation mode was through pump depletion.

Saturn's recurring great white storms play an important role in modifying its atmosphere. In 2010, such a storm with clouds encircling the planet occurred in the northern hemisphere. An interesting phenomenon of this storm is that the associated bright clouds expanded asymmetrically with respect to latitude, such that the southern boundary of the bright clouds moved ~2.7 times as far as the northern boundary during an 8-month period. Based on the wind and temperature fields retrieved from the Cassini visible and infrared observations, we explore the mechanism behind this asymmetrical expansion. Our analysis shows that the northern edge, which quickly stopped moving, coincides with the largest meridional gradient of the quasi-geostrophic potential vorticity (PV) in the region of interest, which is coincident with the strongest jet in the region, suggesting this forms an effective barrier to meridional transport, much like a polar vortex. In contrast, the storm's southern edge, which kept moving, passed through weaker PV gradients and jets. For the threshold value of the meridional gradient of PV needed to form an effective barrier to meridional transport in Saturn's mid-latitude upper-troposphere, we estimate lower and upper bounds of ~2.1 × 10−11 m−1 s−1 and ~3.6 × 10−11 m−1 s−1.

Kinetic modeling of laser-ion beam generation from the “break-out afterburner” (BOA) has been modeled for several deuteron-rich solid-density target foils. Modeling the transport of these beams in a beryllium converter shows as much as a fourfold increase in neutron yield over the present state of the art through the use of alternative target materials. Additionally, species-separation dynamics during the BOA can be exploited to control the hardness of the neutron spectra, of interest for, for example, enhancing penetrability in shielded material in active neutron interrogation settings.

Disrupted neural synchrony may be a primary electrophysiological abnormality in autism spectrum disorders (ASD), altering communication between discrete brain regions and contributing to abnormalities in patterns of connectivity within identified neural networks. Studies exploring brain dynamics to comprehensively characterize and link connectivity to large-scale cortical networks and clinical symptoms are lagging considerably. Patterns of neural coherence within the Default Mode Network (DMN) and Salience Network (SN) during resting state were investigated in 12 children with ASD (MAge = 9.2) and 13 age and gender-matched neurotypicals (NT) (MAge = 9.3) with magnetoencephalography. Coherence between 231 brain region pairs within four frequency bands (theta (4-7 Hz), alpha, (8-12 Hz), beta (13-30 Hz), and gamma (30-80 Hz)) was calculated. Relationships between neural coherence and social functioning were examined. ASD was characterized by lower synchronization across all frequencies, reaching clinical significance in the gamma band. Lower gamma synchrony between fronto-temporo-parietal regions was observed, partially consistent with diminished default mode network (DMN) connectivity. Lower gamma coherence in ASD was evident in cross-hemispheric connections between: angular with inferior/middle frontal; middle temporal with middle/inferior frontal; and within right-hemispheric connections between angular, middle temporal, and inferior/middle frontal cortices. Lower gamma coherence between left angular and left superior frontal, right inferior/middle frontal, and right precuneus and between right angular and inferior/middle frontal cortices was related to lower social/social-communication functioning. Results suggest a pattern of lower gamma band coherence in a subset of regions within the DMN in ASD (angular and middle temporal cortical areas) related to lower social/social-communicative functioning. Autism Res 2018, 11: 434-449. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY Communication between different areas of the brain was observed in children with ASD and neurotypical children while awake, but not working on a task. Magnetoencephalography was used to measure tiny magnetic fields naturally generated via brain activity. The brains of children with ASD showed less communication between areas that are important for social information processing compared to the brains of neurotypical children. The amount of communication between these areas was associated with social and social communication difficulties.

Time-out (TO) is one of the most common and effective disciplinary tactics used to address problem behavior; however, parents rate TO as one of the least useful behavior modification techniques. This may be due to a discrepancy between empirically supported TO procedures and how mothers are actually conducting TO. Fifty-five mothers were asked to define TO, provide information on how they conduct TO, and identify errors in TO procedures. Results indicate that maternal knowledge and implementation of TO differs considerably from the empirical ideal, potentially impacting the utility and frequency of TO usage in the home to address child problem behaviors.

Behavioral intervention is the only treatment for pediatric feeding problems with well documented empirical support. However, parents may be hesitant to pursue behavioral intervention because of concerns about possible negative side effects on child behavioral health and the parent-child relationship. This study investigated associations between behavioral feeding treatment and parenting stress, internalizing and externalizing behavior problems in young children, and parent-child attachment quality.Participants included 16 mother-child dyads seeking treatment from a behavioral feeding clinic at a large Midwestern university medical center. Children were between the ages of 30 and 45 months (adjusted) at baseline. Caregivers completed the Child Behavior Checklist for ages 1.5 to 5 (CBCL/1.5-5), the Parenting Stress Index, 3rd Edition Short Form (PSI/SF), and mother-child dyads participated in the Strange Situation procedure at baseline and again after 6 months. The treatment group (n = 12) began outpatient behavioral feeding intervention following the baseline evaluation, whereas the control group (n = 12) remained on the clinic waitlist until after the 6-month follow-up.The treatment group demonstrated decreases in internalizing and externalizing child behavior problems and parenting stress compared with the control group. No significant differences were demonstrated in parent-child attachment quality within or between groups.Behavioral feeding intervention had positive effects on perceptions of child emotional and behavioral functioning and maternal parenting stress. Intervention also did not impact the quality of the mother-child attachment relationship. Further research with a larger sample size and additional observational measures of behavior is needed to support the replicability and generalizability of these results.

Conventional explicit electromagnetic particle-in-cell (PIC) algorithms do not conserve discrete energy exactly. Time-centered fully implicit PIC algorithms can conserve discrete energy exactly, but may introduce large dispersion errors in the light-wave modes. This can lead to intolerable simulation errors where accurate light propagation is needed (e.g. in laser-plasma interactions). In this study, we selectively combine the leap-frog and Crank-Nicolson methods to produce an exactly energy- and charge-conserving relativistic electromagnetic PIC algorithm. Specifically, we employ the leap-frog method for Maxwell's equations, and the Crank-Nicolson method for the particle equations. The semi-implicit formulation still features a timestep CFL, but facilitates exact global energy conservation, exact local charge conservation, and preserves the dispersion properties of the leap-frog method for the light wave. The algorithm employs a new particle pusher designed to maximize efficiency and minimize wall-clock-time impact vs. the explicit alternative. It has been implemented in a code named iVPIC, based on the Los Alamos National Laboratory VPIC code ( https://github.com/losalamos/vpic ). We present numerical results that demonstrate the properties of the scheme with sample test problems: relativistic two-stream instability, Weibel instability, and laser-plasma instabilities.

The engineered macro-pore foam provides a new way to study thermonuclear burn physics by utilizing capsules containing deuterated (D) foam and filling tritium (T) gas in the engineered macro-pores. The implosion of a thermonuclear capsule filled with an engineered macro-pore foam will be complex due to the interaction of a shock wave with the engineered macro-pores. It is our goal to quantify how substantially complex foam structures affect the shape of shock and bulk shock speed. A cylinder-shape shock tube experiment has been designed and performed at the Omega Laser Facility. In order to examine how a foam structure will affect shock propagation, we performed several tests varying (1) engineered macro-pore size, (2) average foam density, and (3) with/without neopentane (C5H12) gas. X-ray radiographic data indicate that shock speed through engineered macro-pore foams depends strongly on average foam density and less on pore size. Experimental shock propagation data helped guide two numerical simulation approaches: (1) a 2D simulation with homogenizing foams rather than explicitly simulating engineered macro-pores and (2) a 2D toroidal-pore approximation adopting a toroidal-tube geometry to model engineered macro-pores.

The MARBLE project is a novel inertial confinement fusion platform for studying the development of atomic mixing and temperature equilibration in inertial confinement fusion implosions and their impact on thermonuclear burn. Experiments involve the laser-driven implosion of capsules filled with deuterated engineered foams whose pores are filled with a gaseous mixture of hydrogen and tritium. By varying the size of the foam pores, we can study the timescale of the development of atomic mix relative to the development of thermal equilibrium between species. In contrast, previous separated reactant experiments have only provided information on the total amount of mix mass. We report on the series of MARBLE experiments [first reported in Haines et al., Nat. Commun. 11, 544 (2020)] performed on the University of Rochester's OMEGA laser facility and detailed and highly resolved three-dimensional radiation-hydrodynamic simulations of the implosions. In both the experimental and simulation results, we observe that the reactants do not achieve thermal equilibrium during the course of the implosion except in atomically mixed regions—i.e., that atomic mixing develops faster than thermal equilibration between species. The results suggest that ion temperature variations in the mixture are at least as important as reactant concentration variations for determining the fusion reaction rates.

Revolver and Double Shell Inertial Confinement Fusion capsule designs hope to achieve a robust volumetric thermonuclear burn via the use of a high-Z pusher shell filled with a cryogenic D–T fuel. Unfortunately, mix of the pusher material into the fuel (gas) may adversely impact the burn performance. Hydrodynamic instability of the metal/gas interface as the mix source is an obvious concern, but 1D effects may also be detrimental. Such effects include plasma diffusion at material interfaces, which has been the subject of numerous theoretical, computational, and experimental investigations. However, other 1D mix mechanisms may exist, which have yet to be thoroughly explored. In particular, plasma kinetic effects may drive the mix when a shock breaks out of the metal/gas interface. Using the state-of-the-art, hybrid (kinetic-ion/fluid electron), multi-ion Vlasov–Fokker–Planck code, iFP, we show that shock-driven kinetic effects can reconfigure the interface and the interfacial width subsequently grows diffusively. Finally, we consider any implications for high-Z pusher designs.

Previous research found repetitive and restricted behaviors (RRBs) were less predictive of Autism Spectrum Disorder (ASD) in females, indicating the diagnostic construct may not adequately describe RRB presentations in females. This mixed-methods study investigated the female presentation of RRBs, namely restricted interests, in a clinic sample of 125 participants (n = 40 female; ages 2-83 years; 75 ASD). RRB severity did not differ between sexes, t = 1.69, p = 0.094, though male participants scored higher on the Restricted Behavior subscale. Qualitatively, females demonstrated a narrower range of restricted interests and expressed them in a socially oriented manner compared to males. The results suggest unique quantitative and qualitative sex differences in RRB profiles that could shed light on the female ASD phenotype.

Within the aquatic environment, bacteria can be found either attached to various substrates or existing as free-living single or aggregated cells in the water column. Substrates to which bacteria are likely to attach include marine snow, fecal and detrital particles in the water column, sediment particles, and aquatic plants. The sample preparation method delineated overcomes the problems by utilizing a combination of chemical and physical procedures for dispersing the bacteria from their attached sites or aggregated forms. The method involves initial fixation and strengthening of bacteria in the sample with formaldehyde, followed by addition of dispersant, tetrasodium pyrophosphate (PPi), and an application of ultrasound for physical separation of the bacterial cells. The method allows for bacterial enumeration from aquatic substrates that are difficult or impossible to enumerate via the use of standard methods. The sample preparation method disperses bacteria evenly and thereby decreases variance in bacterial counts between microscopic fields.