Nanodust detection near 1 AU from spectral analysis of Cassini/RPWS radio data

Nanodust grains of a few nanometer in size are produced near the Sun by collisional break-up of larger grains and picked-up by the magnetized solar wind. They have so far been detected at 1 AU by only the two STEREO spacecraft. Here we analyze the spectra measured by the radio and plasma wave instrument onboard Cassini during the cruise phase close to Earth orbit; they exhibit bursty signatures similar to those observed by the same instrument in association to nanodust stream impacts on Cassini near Jupiter. The observed wave level and spectral shape reveal impacts of nanoparticles at about 300 km/s, with an average flux compatible with that observed by the radio and plasma wave instrument onboard STEREO and with the interplanetary flux models

Dust detection by the wave instrument on STEREO: nanoparticles picked up by the solar wind?

The STEREO/WAVES instrument has detected a very large number of intense voltage pulses. We suggest that these events are produced by impact ionisation of nanoparticles striking the spacecraft at a velocity of the order of magnitude of the solar wind speed. Nanoparticles, which are half-way between micron-sized dust and atomic ions, have such a large charge-to-mass ratio that the electric field induced by the solar wind magnetic field accelerates them very efficiently. Since the voltage produced by dust impacts increases very fast with speed, such nanoparticles produce signals as high as do much larger grains of smaller speeds. The flux of 10-nm radius grains inferred in this way is compatible with the interplanetary dust flux model. The present results may represent the first detection of fast nanoparticles in interplanetary space near Earth orbit.Comment: In press in Solar Physics, 13 pages, 5 figure

Tracking CMEs using data from the Solar Stormwatch project; observing deflections and other properties

With increasing technological dependence, society is becoming ever more affected by changes in the near-Earth space environment caused by space weather. The primary driver of these hazards are coronal mass ejections (CMEs). Solar Stormwatch is a citizen science project in which volunteers participated in several activities which characterised CMEs in the remote sensing images from the SECCHI instrument package on the twin STEREO spacecraft. Here, we analyse the results of the 'Track-it-back' activity, in which CMEs were tracked back through the COR2, COR1 and EUVI images. Analysis of the COR1, COR2 and EUVI data together allows CMEs to be studied consistently throughout the whole field-of-view spanned by these instruments (out to 15 solar radii). 4783 volunteers took part in this activity, creating a dataset containing 23,801 estimates of CME timing, location and size. We used this data to produce a catalogue of 41 CMEs, which is the first to consistently track CMEs through each of these instruments. We assess how the CME speeds, propagation directions and widths vary as the CMEs propagate through the fields of view of the different imagers. In particular, we compare the observed CME deflections between the COR1 and COR2 fields of view to the separation between the CME source region and the heliospheric current sheet (HCS), demonstrating that, in general, these CMEs appear to deflect towards the HCS, consistent with other modelling studies of CME propagation

Modifying effect of dual antiplatelet therapy on incidence of stent thrombosis according to implanted drug-eluting stent type

Aim To investigate the putative modifying effect of dual antiplatelet therapy (DAPT) use on the incidence of stent thrombosis at 3 years in patients randomized to Endeavor zotarolimus-eluting stent (E-ZES) or Cypher sirolimus-eluting stent (C-SES). Methods and results Of 8709 patients in PROTECT, 4357 were randomized to E-ZES and 4352 to C-SES. Aspirin was to be given indefinitely, and clopidogrel/ticlopidine for ≥3 months or up to 12 months after implantation. Main outcome measures were definite or probable stent thrombosis at 3 years. Multivariable Cox regression analysis was applied, with stent type, DAPT, and their interaction as the main outcome determinants. Dual antiplatelet therapy adherence remained the same in the E-ZES and C-SES groups (79.6% at 1 year, 32.8% at 2 years, and 21.6% at 3 years). We observed a statistically significant (P = 0.0052) heterogeneity in treatment effect of stent type in relation to DAPT. In the absence of DAPT, stent thrombosis was lower with E-ZES vs. C-SES (adjusted hazard ratio 0.38, 95% confidence interval 0.19, 0.75; P = 0.0056). In the presence of DAPT, no difference was found (1.18; 0.79, 1.77; P = 0.43). Conclusion A strong interaction was observed between drug-eluting stent type and DAPT use, most likely prompted by the vascular healing response induced by the implanted DES system. These results suggest that the incidence of stent thrombosis in DES trials should not be evaluated independently of DAPT use, and the optimal duration of DAPT will likely depend upon stent type (Clinicaltrials.gov number NCT00476957

Smart PCM Encoder

International Telemetering Conference Proceedings / October 30-November 02, 1995 / Riviera Hotel, Las Vegas, NevadaIn this paper, a new concept in PCM telemetry encoding equipment is described. Existing "programmable" PCM encoders allow only simple changes in the functionality of the hardware, such as input gain, offset, and word formatting. More importantly, these encoders do not provide capability for "in-flight" processing of signals and in general have not taken advantage of existing hardware and software digital signal processing technology. In-flight processing of signals can provide a significant reduction in the required transmission bandwidth, allowing additional data that may not have otherwise been transmitted to be sent on the telemetry channel. A modular digital signal processor (DSP) based PCM encoder architecture is described that has a set of on-board processing algorithms configurable via a simple-to-use graphical user interface. Algorithms included are compression (lossy and lossless), Fourier transforms of various resolutions (typically followed by peak detection to provide a data rate reduction), extreme values (max, min, rms), time filtering, regression, trajectory prediction, and serial data stream processing. Custom algorithms can be developed and included as part of the suite of processing algorithms. The preprocessing algorithms exist as firmware on the DSPs and can accommodate as many different signals as the processing bandwidth of the DSP can handle. Typically one DSP can handle many input signals and different algorithms. The encoder is programmable via a standard RS-232 serial interface allowing the signal input configuration, telemetry frame layout, and on-board processing algorithms to be changed quickly.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection

operative treatment of unstable distal radius fractures: the dorsal plate revisited

Purpose: To determine the functional outcome and complications following dorsal plating for unstable fractures of the distal radius.Methods: We searched our IRB-approved Distal Radius Fracture Databases and identified all patients who were treated with a dorsally applied plate. Thirty-four distal radius fractures in 33 patients with a mean age of 50 years and average follow-up of 14 months were treated with a dorsal locking plate from 2007 to 2015.Results: Fifteen and six patients had dorsal shearing fracture pattern and delayed presentation, respectively. There were no  loss of reduction, malunion, or nonunion. Average VAS pain score was 2.1/10. Eight patients (23%) required hardware removal, one of which was due to extensor tendon rupture (3%) and five due to extensor tendon irritation (15%).Conclusions: Dorsal locked plating of distal radius fractures with newer low-profile implants is a viable option for particular fractures types, such as the dorsal rim shear type fractures.

The Feasibility of Launching Small Satellites with a Light Gas Gun

This paper summarizes a study conducted for the Defense Advanced Research Projects Agency of the technical and economic feasibility of using a light gas gun to launch small satellites. The launcher concept is based upon a distributed-injection gun, which, in principle, can produce high muzzle velocities at relatively low acceleration levels. To establish initial system requirements for the launcher and spacecraft, the deployment of a large constellation of telecommunications satellites is chosen as a reference mission. This choice reflects the dominance of telecommunications in current commercial LEO market projections, but the results obtained for this mission are later generalized to encompass other applications. The spacecraft mass budget is most affected by large mass fraction allocations for structure and power subsystems. High acceleration loads are responsible for the increase in structural mass, and the increase in battery mass is tied to volume limitations that restrict the battery technology that can be used. The results of the financial analysis suggest that achieving a competitive specific launch cost requires a launch rate beyond current market projections. But a low-volume launch business could provide an attractive total mission cost relative to current systems

Ecological System Influences in the Treatment of Pediatric Chronic Pain

Family, school and the peer network each shape the chronic pain experience of the individual child, and each of these contexts also represents a domain of functioning often impaired by chronic pain. The goal of the present article is to summarize what is known about these bidirectional influences between children with pain and the social systems that surround them. Case reports that illustrate these complex, transactional forces and their ultimate impact on the child’s pain-related functioning are included. A case involving siblings participating in an intensive interdisciplinary program for functional restoration and pain rehabilitation highlights how parents change through this treatment approach and how this change is vital to the child’s outcomes. Another case involving a child undergoing intensive interdisciplinary treatment illustrates how school avoidance can be treated in the context of pain rehabilitation, resulting in successful return to the regular school environment. Finally, an acceptance and commitment therapy-focused group intervention for children with sickle cell disease and their parents demonstrates the benefits of peer contact as an element of the therapeutic intervention