Energetic Electron Precipitation Driven by Electromagnetic Ion Cyclotron Waves from ELFIN's Low Altitude Perspective

We review comprehensive observations of electromagnetic ion cyclotron (EMIC) wave-driven energetic electron precipitation using data collected by the energetic electron detector on the Electron Losses and Fields InvestigatioN (ELFIN) mission, two polar-orbiting low-altitude spinning CubeSats, measuring 50-5000 keV electrons with good pitch-angle and energy resolution. EMIC wave-driven precipitation exhibits a distinct signature in energy-spectrograms of the precipitating-to-trapped flux ratio: peaks at >0.5 MeV which are abrupt (bursty) (lasting ∼17 s, or Δ L ∼ 0.56 ) with significant substructure (occasionally down to sub-second timescale). We attribute the bursty nature of the precipitation to the spatial extent and structuredness of the wave field at the equator. Multiple ELFIN passes over the same MLT sector allow us to study the spatial and temporal evolution of the EMIC wave - electron interaction region. Case studies employing conjugate ground-based or equatorial observations of the EMIC waves reveal that the energy of moderate and strong precipitation at ELFIN approximately agrees with theoretical expectations for cyclotron resonant interactions in a cold plasma. Using multiple years of ELFIN data uniformly distributed in local time, we assemble a statistical database of ∼50 events of strong EMIC wave-driven precipitation. Most reside at L ∼ 5 - 7 at dusk, while a smaller subset exists at L ∼ 8 - 12 at post-midnight. The energies of the peak-precipitation ratio and of the half-peak precipitation ratio (our proxy for the minimum resonance energy) exhibit an L -shell dependence in good agreement with theoretical estimates based on prior statistical observations of EMIC wave power spectra. The precipitation ratio's spectral shape for the most intense events has an exponential falloff away from the peak (i.e., on either side of ∼ 1.45 MeV). It too agrees well with quasi-linear diffusion theory based on prior statistics of wave spectra. It should be noted though that this diffusive treatment likely includes effects from nonlinear resonant interactions (especially at high energies) and nonresonant effects from sharp wave packet edges (at low energies). Sub-MeV electron precipitation observed concurrently with strong EMIC wave-driven >1 MeV precipitation has a spectral shape that is consistent with efficient pitch-angle scattering down to ∼ 200-300 keV by much less intense higher frequency EMIC waves at dusk (where such waves are most frequent). At ∼100 keV, whistler-mode chorus may be implicated in concurrent precipitation. These results confirm the critical role of EMIC waves in driving relativistic electron losses. Nonlinear effects may abound and require further investigation.

Short Chorus Wave Packets: Generation Within Chorus Elements, Statistics, and Consequences on Energetic Electron Precipitation

Short and intense lower-band chorus wave packets are ubiquitous in the Earth's outer radiation belt. In this article, we perform various Vlasov hybrid simulations, with one or two triggering waves, to study the generation of short chorus packets/subpackets inside long rising tone elements. We show that the length of the generated short wave packets is consistent with a criterion of resonance non-overlap for two independent superposed waves, and that these chorus packets have similar characteristics as in Van Allen Probes observations. We find that short wave packets are mainly formed near the middle/end of long rising tones for moderate linear growth rates, and everywhere for stronger linear growth rates. Finally, we analyze an event characterized by Time History of Events and Macroscale Interactions during Substorms spacecraft measurements of chorus rising tones near the equator and simultaneous measurements by low altitude ELFIN CubeSats of precipitating and trapped electron fluxes in the same sector. The measured precipitating electron fluxes are well recovered by test particle simulations performed using measured plasma and wave properties. We show that short chorus wave packets of moderate amplitudes (160-250 pT) essentially lead to a more diffusive-like transport of 50-200 keV electrons toward the loss cone than long packets. In contrast, long chorus packets are found to produce important nonlinear effects via anomalous trapping, which significantly reduces electron precipitation below 150 keV, especially for higher wave amplitudes.

Predictors of voter support for the legalization of recreational cannabis use and supply via a national referendum

BACKGROUND

A national referendum to legalise recreational cannabis use and supply in New Zealand via the Cannabis Legalisation and Control Bill (CLCB) was recently narrowly defeated. Understanding the underlying factors for this result can inform the cannabis legalisation debate in other countries.

AIMS

To investigate predictors of voter support for and opposition to the CLCB.

METHOD

A representative population panel of 1,022 people completed an online survey of intended voting on the CLCB referendum, which included questions on demographics, drug use history, medicinal cannabis, perceptions of the health risk and moral views of cannabis use, political affiliation, religiosity, community size and reading of the CLCB. Regression models were developed to predict support for the CLCB, with additional predictor variables added over successive iterations.

RESULTS

The most robust predictors of support for the CLCB were use of and policy support for medicinal cannabis use, voting for a left-wing political party, having a positive moral view of cannabis use, living in a small town and having read the CLCB. Predictors of opposing the CLCB were voting for right-wing parties, considering "frequent" cannabis use to be a high health risk, and lifetime use of other drugs. Age, ethnicity, education, employment status, religiosity and lifetime cannabis use were not significant predictors after controlling for other variables.

CONCLUSIONS

Support for cannabis legalization was not based on broad demographics, but rather specific views concerning the medicinal benefit, morality of cannabis use, health risk of frequent cannabis use, political party affiliation, and knowledge of the proposed regulatory controls of the CLCB. The influence of moral views of cannabis use on voting behaviour suggest the need to debate the right to use cannabis. The importance of knowledge of the proposed regulatory controls of the CLCB on voting underlines the need to raise awareness of proposed regulatory controls during debate.

Leveraging Emergency Department Information Systems to Address Palliative Care Needs of ED Patients During the COVID Pandemic

The arrival of the COVID-19 pandemic to hospitals in New York City stressed our emergency departments (ED) with high patient volume, stresses on hospital resources and the arrival of numerous high acuity, critically ill patients. Amid this time, we sought to leverage the ED Information Systems (EDIS), to assist in connecting critically ill patients, their families, and providers in the ED with palliative care resources. We discuss 4 innovative, thoughtful solutions to assist ED providers in identifying and addressing the acute and unique palliative care needs of COVID patients.

Assessing the sport-specific and functional characteristics of back pain in horse riders

Currently, no standardised screening tools nor established interventions are available to address the characteristics of back pain (BP) specifically in horse riders. Therefore, the aim of this case-control study is to explore sport-specific and functional characteristics of BP in horse riders. 16 professional and 16 amateur riders (25±7 years) participated in two questionnaires (a sport-specific questionnaire and the Oswestry Disability Index questionnaire) and were examined via the physical functional movement screening (FMS) and Luomajoki’s motor control (MC) screening. The lifetime prevalence of BP was as high as 81%, and spinal discomfort in horse riders was mainly located in the lumbar spine. Professional riders revealed significantly higher prevalence of BP in the last month before assessment (P=0.014) than amateur riders. Compared to horse riders using dressage or multiple saddle types, show jumping riders (n=10) who only use jumping saddles (P=0.027) also revealed higher BP prevalence. Horse riders with lower scores on the FMS and MC screening, and thereby with more movement dysfunctions, were found to experience higher levels of pain (r=-0.582, P=0.001; r=-0.404, P=0.024, respectively) and disability caused by BP (r=-0.688; P<0.001; r=-0.474; P=0.006, respectively). Both physical screening tools are found to be clinically relevant enabling investigators to identify objective functional characteristics related to BP in horse riders. The high prevalence of BP in riders is a clinically important finding that should be explored further to elucidate the causes and subsequently guide occupational health in horse riders.

The ELFIN Mission

The Electron Loss and Fields Investigation with a Spatio-Temporal Ambiguity-Resolving option (ELFIN-STAR, or heretoforth simply: ELFIN) mission comprises two identical 3-Unit (3U) CubeSats on a polar (∼93^∘ inclination), nearly circular, low-Earth (∼450 km altitude) orbit. Launched on September 15, 2018, ELFIN is expected to have a >2.5 year lifetime. Its primary science objective is to resolve the mechanism of storm-time relativistic electron precipitation, for which electromagnetic ion cyclotron (EMIC) waves are a prime candidate. From its ionospheric vantage point, ELFIN uses its unique pitch-angle-resolving capability to determine whether measured relativistic electron pitch-angle and energy spectra within the loss cone bear the characteristic signatures of scattering by EMIC waves or whether such scattering may be due to other processes. Pairing identical ELFIN satellites with slowly-variable along-track separation allows disambiguation of spatial and temporal evolution of the precipitation over minutes-to-tens-of-minutes timescales, faster than the orbit period of a single low-altitude satellite (T_orbit ∼ 90 min). Each satellite carries an energetic particle detector for electrons (EPDE) that measures 50 keV to 5 MeV electrons with Δ E/E < 40% and a fluxgate magnetometer (FGM) on a ∼72 cm boom that measures magnetic field waves (e.g., EMIC waves) in the range from DC to 5 Hz Nyquist (nominally) with <0.3 nT/sqrt(Hz) noise at 1 Hz. The spinning satellites (T_spin ∼ 3 s) are equipped with magnetorquers (air coils) that permit spin-up or -down and reorientation maneuvers. Using those, the spin axis is placed normal to the orbit plane (nominally), allowing full pitch-angle resolution twice per spin. An energetic particle detector for ions (EPDI) measures 250 keV - 5 MeV ions, addressing secondary science. Funded initially by CalSpace and the University Nanosat Program, ELFIN was selected for flight with joint support from NSF and NASA between 2014 and 2018 and launched by the ELaNa XVIII program on a Delta II rocket (with IceSatII as the primary). Mission operations are currently funded by NASA. Working under experienced UCLA mentors, with advice from The Aerospace Corporation and NASA personnel, more than 250 undergraduates have matured the ELFIN implementation strategy; developed the instruments, satellite, and ground systems and operate the two satellites. ELFIN's already high potential for cutting-edge science return is compounded by concurrent equatorial Heliophysics missions (THEMIS, Arase, Van Allen Probes, MMS) and ground stations. ELFIN's integrated data analysis approach, rapid dissemination strategies via the SPace Environment Data Analysis System (SPEDAS), and data coordination with the Heliophysics/Geospace System Observatory (H/GSO) optimize science yield, enabling the widest community benefits. Several storm-time events have already been captured and are presented herein to demonstrate ELFIN's data analysis methods and potential. These form the basis of on-going studies to resolve the primary mission science objective. Broad energy precipitation events, precipitation bands, and microbursts, clearly seen both at dawn and dusk, extend from tens of keV to >1 MeV. This broad energy range of precipitation indicates that multiple waves are providing scattering concurrently. Many observed events show significant backscattered fluxes, which in the past were hard to resolve by equatorial spacecraft or non-pitch-angle-resolving ionospheric missions. These observations suggest that the ionosphere plays a significant role in modifying magnetospheric electron fluxes and wave-particle interactions. Routine data captures starting in February 2020 and lasting for at least another year, approximately the remainder of the mission lifetime, are expected to provide a very rich dataset to address questions even beyond the primary mission science objective.

Lead ethyl dithiocarbamates: efficient single-source precursors to PbS nanocubes

Lead ethyl dithiocarbamates have been successfully used as single-source precursors for the deposition of PbS using spin coating followed by annealing at moderate temperatures. The thin films were characterized using a powder X-ray diffractometer and were found to be face-centred cubic with the (200) plane being the most preferred orientation. Scanning electron microscopy images showed the formation of well-defined cubes. Optical band gaps of PbS thin films were estimated using Tauc plots as 0.72, 0.73 and 0.77 eV at annealing temperatures of 250, 300 and 400°C. These band gaps were all blue shifted from the bulk value of 0.41 eV. Energy-dispersive X-ray analysis was used to determine the composition of the thin films which showed an approximately 1 : 1 Pb to S ratio.

The Far Ultra-Violet imager on the ICON mission

ICON Far UltraViolet (FUV) imager contributes to the ICON science objectives by providing remote sensing measurements of the daytime and nighttime atmosphere/ionosphere. During sunlit atmospheric conditions, ICON FUV images the limb altitude profile in the shortwave (SW) band at 135.6 nm and the longwave (LW) band at 157 nm perpendicular to the satellite motion to retrieve the atmospheric O/N2 ratio. In conditions of atmospheric darkness, ICON FUV measures the 135.6 nm recombination emission of O+ ions used to compute the nighttime ionospheric altitude distribution. ICON Far UltraViolet (FUV) imager is a CzernyTurner design Spectrographic Imager with two exit slits and corresponding back imager cameras that produce two independent images in separate wavelength bands on two detectors. All observations will be processed as limb altitude profiles. In addition, the ionospheric 135.6 nm data will be processed as longitude and latitude spatial maps to obtain images of ion distributions around regions of equatorial spread F. The ICON FUV optic axis is pointed 20 degrees below local horizontal and has a steering mirror that allows the field of view to be steered up to 30 degrees forward and aft, to keep the local magnetic meridian in the field of view. The detectors are micro channel plate (MCP) intensified FUV tubes with the phosphor fiber-optically coupled to Charge Coupled Devices (CCDs). The dual stack MCP-s amplify the photoelectron signals to dominate the CCD noise and the rapidly scanned frames are co-added to digitally create 12-second integrated images. Digital on-board signal processing is used to compensate for geometric distortion and satellite motion and to achieve data compression. The instrument was originally aligned in visible light by using a special grating and visible cameras. Final alignment, functional and environmental testing and calibration were performed in a large vacuum chamber with a UV source. The test and calibration program showed that ICON FUV meets its design requirements and is ready to be launched on the ICON spacecraft.

COST SAVINGS AND PALLIATIVE CARE REFERRALS FROM THE EMERGENCY DEPARTMENT

Early palliative care consultation ha the potential to provide comfort to patients and families, and decrease costs and length of stay.

The National Immunization Information Hotline

The National Immunization Information Hotline (NIIH) has been providing information regarding immunizations to the public and to health care professionals since March 1997. We describe the operations of the NIIH, its experience over the first two and a half years of operation and lessons learned for other immunization hotlines. From 1998-2000, the hotline answered 246,859 calls. Calls concerning immunization information requests totaled 175,367; data about the calls were collected from 35,102. Approximately a third of the 35,102 calls were from health care providers. Of the remaining calls from the public, the greatest number of calls concerned childhood immunizations. Immunization schedule queries from the public increased 323.0% from 1998 to 2000. While the major goal of the NIIH is to provide accurate and reliable information to the public and to health care providers, data from the hotline can be used to monitor changes over time in calls concerning inquiries about the immunization schedule in addition to other variables of interest.

Development of a general ability index for the Wechsler Adult Intelligence Scale--Third Edition

The Wechsler Adult Intelligence Scale--Third Edition (WAIS-III; D. Wechsler, 1997) permits the calculation of both traditional IQ and index scores. However, if only the subtests constituting the index scores are administered, especially those yielding the Verbal Comprehension and Perceptual Organization Indexes, there is no equivalent measure of Full Scale IQ. Following the procedure for calculating a General Ability Index (GAI; A. Prifitera, L. G. Weiss, & D. H. Saklofske, 1998) for the Wechsler Intelligence Scale for Children--Third Edition (D. Wechsler, 1991), GAI normative tables for the WAIS-III standardization sample are reported here.

Development of a general ability index for the Wechsler Adult Intelligence Scale--Third Edition

The Wechsler Adult Intelligence Scale--Third Edition (WAIS-III; D. Wechsler, 1997) permits the calculation of both traditional IQ and index scores. However, if only the subtests constituting the index scores are administered, especially those yielding the Verbal Comprehension and Perceptual Organization Indexes, there is no equivalent measure of Full Scale IQ. Following the procedure for calculating a General Ability Index (GAI; A. Prifitera, L. G. Weiss, & D. H. Saklofske, 1998) for the Wechsler Intelligence Scale for Children--Third Edition (D. Wechsler, 1991), GAI normative tables for the WAIS-III standardization sample are reported here.

Confirmatory factor analysis of a test used for certification in sport scuba diving

The purpose of this study was to confirm the underlying factor structure of the entry-level scuba diving certification test published by the National Association of Underwater Instructors (NAUI). The test measures knowledge mastery across 6 content areas. A sample of 400 female and male entry-level scuba diving students aged from 18 to 47 years participated in the study. A rigorous structural equation modeling approach was used to confirm the factor structure of the test. The results verify that two latent factors or constructs accurately represent knowledge mastery for entry-level scuba diving students. Also, cross-validation procedures were used to examine the accuracy of measurement model replication. Collectively, these findings support the construct validity of the test.

Comparison of 7 and 8 French guiding catheters for elective PTCA: results of a prospective randomized trial

A prospective randomized trial was performed to detect technical and clinical differences of 7F compared to 8F guiding catheters (GC) used in elective coronary angioplasty (PTCA). One hundred and fifteen patients undergoing elective PTCA with standard balloon dilatation catheters were randomized to 7F (55 pts) or 8F (58 pts) guiding catheters. The endpoints were primarily coronary artery and peripheral vascular complications; and secondarily, technical details and quantitative and qualitative angiographic quality. There was no difference between 7F or 8F GC for development of coronary or peripheral vascular complications. With 7F GC there was less blood loss (Hct, 3.5 +/- 3.4% vs. 6.5 +/- 9.6%, P = .033), and less contrast medium (160 +/- 88 mL vs. 200 +/- 119 mL, P = .049) used. Angiographic quality was similar, although visualization of lesions in the left anterior descending coronary artery in the left anterior oblique projection was improved with the 8F GC. There is no advantage of 7F GC for the prevention of coronary or peripheral vascular complications, although there was less blood loss and contrast medium used with the 7F systems.

Nitrous oxide sedation causes post-hyperventilation apnoea

We have studied, in six normal subjects, the effect of nitrous oxide sedation on the ventilatory pattern and oxygen saturation using pulse oximetry (SpO2) after hyperventilation to an end-tidal carbon dioxide partial pressure (PE'CO2) of 3 kPa. This value of PE'CO2 was shown to be less than the apnoeic threshold of all these subjects when their ventilation vs PE'CO2 response curves were plotted. All subjects became apnoeic when told to relax following hyperventilation while breathing 75% nitrous oxide for 90 s. Apnoea was defined as cessation of breathing for 20 s or more. The mean duration of apnoea was 78 s (range 29-130 s). All subjects demonstrated arterial desaturation (mean SpO2 75%, range 44-87%). In contrast, following hyperventilation with air, no apnoea was seen in any subject, although there was some evidence of desaturation (mean SpO2 92.5%, range 88-98%). It was concluded that subjects who are sedated with nitrous oxide behave similarly to those who are anaesthetized rather than to those who were fully conscious, in that they become apnoeic below the apnoeic threshold point. The reduction in SpO2 after hyperventilation was explained almost entirely by apnoea and may explain abnormalities of respiratory control and hypoxaemia in patients recovering from general anaesthesia or sedation accompanied by hypocapnia. This mechanism may be of importance in obstetric patients after breathing Entonox, when apnoea and hypoxaemia may reduce oxygen delivery to the fetus.

Thrombolytic therapy with tissue plasminogen activator or streptokinase induces transient thrombin activity

We have determined the plasma level of fibrinopeptide A as a specific index of thrombin activity during the infusion of a thrombolytic agent in patients with acute myocardial infarction. Peripheral venous plasma levels of fibrinopeptide A increased following the initiation of thrombolytic therapy from 2.7 nmol/L to a peak of 13.0 nmol/L at 30 minutes with streptokinase and from 1.1 nmol/L to a peak of 10.7 nmol/L at 90 minutes with tissue plasminogen activator. The amount of fibrinogen converted to fibrin I was determined by integration of the plasma level of fibrinopeptide A over time. The amount of fibrin I formed over the five-hour period from the start of drug infusion was approximately 10 mg/dL in response to either streptokinase or recombinant tissue plasminogen activator. We conclude that activation of coagulation occurs in response to thrombolytic therapy despite heparin administration. This thrombin action, though transient, would be sufficient to cause rethrombosis if localized and incompletely opposed by fibrinolytic activity.

Quantitation of fragment X formation during thrombolytic therapy with streptokinase and tissue plasminogen activator

We have determined the extent of fragment X formation during thrombolytic therapy by integration over time of the plasma fibrinopeptide B beta 1-42 concentration. This peptide is quantitatively released when fragment X is formed by plasmin action on fibrinogen or fibrin I. In response to streptokinase (SK) and rt-PA, 264 +/- 54 and 95 +/- 12 mg/dl respectively of fibrinogen was converted to fragment X. By immunoblotting, fragment X was demonstrated as early as 5 min after SK and 30 min after rt-PA, and was still evident 24 h after treatment. Patients treated with SK showed extensive further plasmin degradation of fragment X to fragments Y and D. Thus fragment X concentrations tend to be more similar in the two groups than would be expected from the extent of fibrinogen breakdown. Fragment X forms clots, but these have lower tensile strength and are more susceptible to further plasmin lysis than clots of fibrin. Thus the similar bleeding observed in the two treatment groups might be a reflection of their similar plasma fragment X concentrations.

Translational control during early Dictyostelium development: possible involvement of poly(A) sequences

A rapid decrease in the translational efficiency of mRNA synthesized during vegetative growth is associated with the initiation of development in Dictyostelium discoideum. In contrast, newly synthesized mRNA associates with polysomes with high efficiency. Discrimination between these two mRNA populations correlates with a rapid shortening of the poly(A) tract on the preexisting mRNA. A model is proposed in which a critical poly(A) length regulates the pattern of protein synthesis by affecting the efficiency with which mRNAs can interact with the translational machinery. The model suggests that transcriptional and translational controls can be coupled by altering the state of adenylation of the preexisting mRNA population. The model allows radical changes in the pattern of protein synthesis without wholesale destruction of preexisting mRNA.

Cranial nerve injury from halo traction

Six of the 70 patients treated with skeletal traction at the Alfred I. duPont Institute exhibited cranial nerve complications. The sixth cranial nerve was most commonly affected by distraction and resulted in weakness in lateral gaze. A combined lesion of the ninth, tenth and twelfth nerves was not an infrequent complication and presented as abnormalities in swallowing, quality of speech, and of tongue movement. It has not been singled out for its significance in the literature but it is potentially the most lethal of the complications. From our review it appears that patients who have had radiation treatment and who have presented with myelomeningocele experience a higher risk of complication in cranial skeletal traction. A definite clinical-pathological correlation could not be made. Frequent monitoring of the patients in skeletal traction is necessary, and prompt recognition of the clinical signs of these complications must be stressed. The complications in the patients of our series subsided upon release of the distraction force.