Spatiotemporal Path-Matching for Comparisons Between Ground- Based and Satellite Lidar Measurements

The spatiotemporal sampling differences between ground-based and satellite lidar data can contribute to significant errors for direct measurement comparisons. Improvement in sample correspondence is examined by the use of radiosonde wind velocity to vary the time average in ground-based lidar data to spatially match coincident satellite lidar measurements. Results are shown for the 26 February 2004 GLAS/ICESat overflight of a ground-based lidar stationed at NASA GSFC. Statistical analysis indicates that improvement in signal correlation is expected under certain conditions, even when a ground-based observation is mismatched in directional orientation to the satellite track

MPL Planetary Boundary Layer Heights at Golden, Fort Collins and Platteville

No abstract availabl

Arctic experiment for ICESat/GLAS ground validation with a Micro-Pulse Lidar at Ny-Alesund, Svalbard

A Micro-Pulse Lidar (MPL) has been operated in Ny-Alesund, Svalbard (78°55\u27N, 11°56\u27E, 0.010 km msl) to collect zenith scattering profiles of aerosols and clouds since 1998. The Ice, Cloud, and land Elevation Satellite (ICESat) was launched by NASA in January 2003 with a single payload instrument, the Geoscience Laser Altimeter System (GLAS), designed for active remote sensing of the atmosphere as well as ice sheet height change in the cryosphere. Overpass experiments for ground validation of the ICESat/GLAS atmospheric measurements were performed in 2003 and 2004. Two case-studies comparing lidar measurements from space-borne GLAS and ground-based MPL in the Arctic are described here for a geometrically thick but optically thin cloud and a geometrically thin but optically thick cloud. The result validates the basic procedure for cloud signal processing and attenuation correction of the GLAS data

Alpha effect due to buoyancy instability of a magnetic layer

A strong toroidal field can exist in form of a magnetic layer in the overshoot region below the solar convection zone. This motivates a more detailed study of the magnetic buoyancy instability with rotation. We calculate the alpha effect due to helical motions caused by a disintegrating magnetic layer in a rotating density-stratified system with angular velocity Omega making an angle theta with the vertical. We also study the dependence of the alpha effect on theta and the strength of the initial magnetic field. We carry out three-dimensional hydromagnetic simulations in Cartesian geometry. A turbulent EMF due to the correlations of the small scale velocity and magnetic field is generated. We use the test-field method to calculate the transport coefficients of the inhomogeneous turbulence produced by the layer. We show that the growth rate of the instability and the twist of the magnetic field vary monotonically with the ratio of thermal conductivity to magnetic diffusivity. The resulting alpha effect is inhomogeneous and increases with the strength of the initial magnetic field. It is thus an example of an "anti-quenched" alpha effect. The alpha effect is nonlocal, requiring around 8--16 Fourier modes to reconstruct the actual EMF based on the actual mean field.Comment: 14 pages, 19 figures 3 tables (submitted to A & A

Glenohumeral Hydrodistension for Postoperative Stiffness After Arthroscopic Primary Rotator Cuff Repair

Background: Postoperative stiffness is a known complication after rotator cuff repair (RCR). Glenohumeral hydrodistension (GH) has been a treatment modality for shoulder pathology but has not been used to treat postoperative stiffness after RCR. Purpose/Hypothesis: The purpose of this study was to identify the risk factors for postoperative stiffness after RCR and review outcomes after treatment with GH. Our hypotheses were that stiffness would be associated with diabetes and hyperlipidemia and correlated with the tendons involved and that patients with stiffness who underwent GH would have significant improvement in range of motion (ROM). Study Design: Case series; Level of evidence, 4.Methods:Included were 388 shoulders of patients who underwent primary RCR by a single surgeon between 2015 and 2019. Shoulders with revision RCRs were excluded. Patient characteristics, medical comorbidities, and perioperative details were collected. A total of 40 shoulders with postoperative stiffness (10.3%) received GH injectate of a 21-mL mixture (15 mL of sterile water, 5 mL of 0.5% ropivacaine, and 1 mL of triamcinolone [10 mg/mL]). The primary outcome measure was ROM in forward flexion, internal rotation, external rotation, and abduction. Statistical tests were performed using analysis of variance. Results: Patients with diabetes had significantly decreased internal rotation at final follow-up after RCR as compared with patients without diabetes. GH to treat stiffness was performed most commonly between 1 and 4 months after RCR (60%), and patients who received GH saw statistically significant improvements in forward flexion, external rotation, and abduction after the procedure. Patients with hyperlipidemia had the most benefit after GH. Among those undergoing concomitant procedures, significantly more patients who had open subpectoral biceps tenodesis underwent GH. Patients who underwent subscapularis repair or concomitant subacromial decompression had significant improvement in ROM after GH. Only 1 patient who received GH underwent secondary surgery for resistant postoperative stiffness. Conclusion: Patients with diabetes had increased stiffness. Patients with a history of hyperlipidemia or concomitant open subpectoral biceps tenodesis were more likely to undergo GH for postoperative stiffness. Patients who underwent subscapularis repair demonstrated the most improvement in ROM after GH. After primary RCR, GH can increase ROM and is a useful adjunct for patients with stiffness to limit secondary surgery

A microchip optomechanical accelerometer

The monitoring of accelerations is essential for a variety of applications ranging from inertial navigation to consumer electronics. The basic operation principle of an accelerometer is to measure the displacement of a flexibly mounted test mass; sensitive displacement measurement can be realized using capacitive, piezo-electric, tunnel-current, or optical methods. While optical readout provides superior displacement resolution and resilience to electromagnetic interference, current optical accelerometers either do not allow for chip-scale integration or require bulky test masses. Here we demonstrate an optomechanical accelerometer that employs ultra-sensitive all-optical displacement read-out using a planar photonic crystal cavity monolithically integrated with a nano-tethered test mass of high mechanical Q-factor. This device architecture allows for full on-chip integration and achieves a broadband acceleration resolution of 10 \mu g/rt-Hz, a bandwidth greater than 20 kHz, and a dynamic range of 50 dB with sub-milliwatt optical power requirements. Moreover, the nano-gram test masses used here allow for optomechanical back-action in the form of cooling or the optical spring effect, setting the stage for a new class of motional sensors.Comment: 16 pages, 9 figure

Multiple Forensic Interviews During Investigations of Child Sexual Abuse: A Cost-Effectiveness Analysis

In cases of suspected child sexual abuse (CSA) some professionals routinely recommend multiple interviews by the same interviewer because any additional details provided might improve decision-making and increase perpetrator convictions. We analyzed alternative policies about child interviewing to estimate the probability that a policy of all children receiving multiple interviews will increase criminal convictions and better protect children. Using decision analysis, we prepared a decision tree reflecting the structure through which a case of possible CSA passes through the health care, welfare, and legal systems with an estimated probability of conviction of the offender. We reviewed the CSA disclosure, criminal justice, and child welfare literature to obtain estimates for the median and range of rates for the steps of disclosure, substantiation, criminal charges, and conviction. Using the R statistical package, our decision analysis model was populated using literature-based estimates. Once the model was populated, we simulated the experiences of 1,000 cases at 250 sets of plausible parameter values representing different hypothetical communities. Multiple interviews increase the likelihood that an offender will be convicted by 6.1% in the average community. Simulations indicate that a policy in which all children seen for a CSA medical evaluation receive multiple interviews would cost an additional $100,000 for each additional conviction. We estimate that approximately 17 additional children would need to be interviewed on more than one occasion to yield one additional conviction. A policy of multiple interviews has implications for the children, for the costs of care, for protecting other children, and for the risk of false prosecution

Assessment of Mixed-Layer Height Estimation from Single-Wavelength Ceilometer Profiles

An assessment of differing boundary/mixed-layer height measurement methods was performed with a focus on the Vaisala CL51 instrument and BLView and STRAT softwares. Of primary interest was determining how these differ- ng methodologies will intercompare when deployed as part of a larger instrument network. The intercomparisons were performed as part of ongoing measurements at the Chemistry And Physics of the Atmospheric Boundary Layer Experiment (CAPABLE) site in Hampton, VA and during the 2014 Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) field campaign that took place in the Denver, CO area. It was observed that data collection methodology is not as important as the processing algorithm, and that, generally speaking, sonde-derived boundary layer heights are higher than LIDAR-derived mixed-layer heights

Engine Gaseous, Aerosol Precursor and Particulated Flight Altitude Conditions

The overall objective of the NASA Atmospheric Effects of Aviation Project (AEAP) is to develop scientific bases for assessing atmospheric impacts of the exhaust emissions by both current and future fleets of subsonic and supersonic aircraft. Among the six primary elements of the AEAP is Emissions Characterization. The objective of the Emission Characterization effort is to determine the exhaust emission constituents and concentrations at the engine exit plane. The specific objective of this engine test is to obtain a database of gaseous and particulate emissions as a function of fuel sulfur and engine operating conditions. The database of the particulate emission properties is to be used as a comparative baseline with subsequent flight measurement. The engine used in this test was a Pratt & Whitney F1OO-200E turbofan engine. Aviation fuel (Jet A) with a range of fuel sulfur was used. Low and high sulfur values are limited by commercially available fuels and by fuel specification limits of O.3% by weight. Test matrix was set by parametrically varying the combustor inlet temperature (T(sub 3) between idle and maximum power setting at simulated SLS and up to five other altitudes for each fuel. Four diagnostic systems, extractive and non-intrusive, were assembled for the gaseous and particulate emissions characterization measurements study. NASA extractive system includes smoke meter and analyzers for measurement of CO, CO2, NO, NOx, O2, total unburnt hydrocarbons (THC), and SO2. Particulate emissions were characterized by University of Missouri-Rolla Mobile Aerosol Sampling System. A chemical ionization mass spectrometer from the Air Force Research Laboratory at Hanscom AFB was used to measure SO2 and HNO3. Aerodyne Research. Inc. used infrared tunable diode laser absorption to measure SO2, SO3, NO, H2O and CO2