Electron Vorticity Indicative of the Electron Diffusion Region of Magnetic Reconnection.

While vorticity defined as the curl of the velocity has been broadly used in fluid and plasma physics, this quantity has been underutilized in space physics due to low time resolution observations. We report Magnetospheric Multiscale (MMS) observations of enhanced electron vorticity in the vicinity of the electron diffusion region of magnetic reconnection. On 11 July 2017 MMS traversed the magnetotail current sheet, observing tailward-to-earthward outflow reversal, current-carrying electron jets in the direction along the electron meandering motion or out-of-plane direction, agyrotropic electron distribution functions, and dissipative signatures. At the edge of the electron jets, the electron vorticity increased with magnitudes greater than the electron gyrofrequency. The out-of-plane velocity shear along distance from the current sheet leads to the enhanced vorticity. This, in turn, contributes to the magnetic field perturbations observed by MMS. These observations indicate that electron vorticity can act as a proxy for delineating the electron diffusion region of magnetic reconnection.

New Closures for More Precise Modeling of Landau Damping in the Fluid Framework.

Incorporation of kinetic effects such as Landau damping into a fluid framework was pioneered by Hammett and Perkins, by obtaining closures of the fluid hierarchy, where the gyrotropic heat flux fluctuations or the deviation of the fourth-order gyrotropic fluid moment are expressed through lower-order fluid moments. To obtain a closure of a fluid model expanded around a bi-Maxwellian distribution function, the usual plasma dispersion function Z(ζ) that appears in kinetic theory or the associated plasma response function R(ζ)=1+ζZ(ζ) has to be approximated with a suitable Padé approximant in such a way that the closure is valid for all ζ values. Such closures are rare, and the original closures of Hammett and Perkins are often employed. Here we present a complete mapping of all plausible Landau fluid closures that can be constructed at the level of fourth-order moments in the gyrotropic limit and we identify the most precise closures. Furthermore, by considering 1D closures at higher-order moments, we show that it is possible to reproduce linear Landau damping in the fluid framework to any desired precision, thus showing convergence of the fluid and collisionless kinetic descriptions.

Coalescence of Macroscopic Flux Ropes at the Subsolar Magnetopause: Magnetospheric Multiscale Observations.

We report unambiguous in situ observation of the coalescence of macroscopic flux ropes by the magnetospheric multiscale (MMS) mission. Two coalescing flux ropes with sizes of ∼1 R_{E} were identified at the subsolar magnetopause by the occurrence of an asymmetric quadrupolar signature in the normal component of the magnetic field measured by the MMS spacecraft. An electron diffusion region (EDR) with a width of four local electron inertial lengths was embedded within the merging current sheet. The EDR was characterized by an intense parallel electric field, significant energy dissipation, and suprathermal electrons. Although the electrons were organized by a large guide field, the small observed electron pressure nongyrotropy may be sufficient to support a significant fraction of the parallel electric field within the EDR. Since the flux ropes are observed in the exhaust region, we suggest that secondary EDRs are formed further downstream of the primary reconnection line between the magnetosheath and magnetospheric fields.

Kinetic scale turbulence and dissipation in the solar wind: key observational results and future outlook.

Turbulence is ubiquitous in the solar wind. Turbulence causes kinetic and magnetic energy to cascade to small scales where they are eventually dissipated, adding heat to the plasma. The details of how this occurs are not well understood. This article reviews the evidence for turbulent dissipation and examines various diagnostics for identifying solar wind regions where dissipation is occurring. We also discuss how future missions will further enhance our understanding of the importance of turbulence to solar wind dynamics.

Bidirectional energy cascades and the origin of kinetic Alfvénic and whistler turbulence in the solar wind.

The observed steep kinetic scale turbulence spectrum in the solar wind raises the question of how that turbulence originates. Observations of keV energetic electrons during solar quiet time suggest them as a possible source of free energy to drive kinetic turbulence. Using particle-in-cell simulations, we explore how the free energy released by an electron two-stream instability drives Weibel-like electromagnetic waves that excite wave-wave interactions. Consequently, both kinetic Alfvénic and whistler turbulence are excited that evolve through inverse and forward magnetic energy cascades.

Detection of small-scale structures in the dissipation regime of solar-wind turbulence.

Recent observations of the solar wind have pointed out the existence of a cascade of magnetic energy from the scale of the proton Larmor radius ρ(p) down to the electron Larmor radius ρ(e) scale. In this Letter we study the spatial properties of magnetic field fluctuations in the solar wind and find that at small scales the magnetic field does not resemble a sea of homogeneous fluctuations, but rather a two-dimensional plane containing thin current sheets and discontinuities with spatial sizes ranging from l >/~ ρ(p) down to ρ(e) and below. These isolated structures may be manifestations of intermittency that localize sites of turbulent dissipation. Studying the relationship between turbulent dissipation, reconnection, and intermittency is crucial for understanding the dynamics of laboratory and astrophysical plasmas.

Wave-vector dependence of magnetic-turbulence spectra in the solar wind.

Using four-point measurements of the Cluster spacecraft, the energy distribution was determined for magnetic field fluctuations in the solar wind directly in the three-dimensional wave-vector domain in the range |k|

Three dimensional anisotropic κ spectra of turbulence at subproton scales in the solar wind.

We show the first three dimensional (3D) dispersion relations and k spectra of magnetic turbulence in the solar wind at subproton scales. We used the Cluster data with short separations and applied the k-filtering technique to the frequency range where the transition to subproton scales occurs. We show that the cascade is carried by highly oblique kinetic Alfvén waves with ω(plas) ≤ 0.1ω(ci) down to k(⊥) ρ(i)∼2. Each k spectrum in the direction perpendicular to B0 shows two scaling ranges separated by a breakpoint (in the interval [0.4,1]k(⊥)ρ(i): a Kolmogorov scaling k(⊥)⁻¹â±7 followed by a steeper scaling ∼k(⊥)⁻4ⁱ5. We conjecture that the turbulence undergoes a transition range, where part of the energy is dissipated into proton heating via Landau damping and the remaining energy cascades down to electron scales where electron Landau damping may predominate.

Ulysses radio and plasma wave observations at high southern heliographic latitudes.

Ulysses spacecraft radio and plasma wave observations indicate that some variations in the intensity and occurrence rate of electric and magnetic wave events are functions of heliographic latitude, distance from the sun, and phase of the solar cycle. At high heliographic latitudes, solartype Ill radio emissions did not descend to the local plasma frequency, in contrast to the emission frequencies of some bursts observed in the ecliptic. Short-duration bursts of electrostatic and electromagnetic waves were often found in association with depressions in magnetic field amplitude, known as magnetic holes. Extensive wave activity observed in magnetic clouds may exist because of unusually large electron-ion temperature ratios. The lower number of intense in situ wave events at high latitudes was likely due to the decreased variability of the high- latitude solar wind.

Implementing national standards for cancer pain management: program model and evaluation.

The purpose of this quasi-experimental (pre and posttest) study was to test a model pain management program (PMP) to implement the American Pain Society (APS) quality assurance standards for the management of acute and chronic cancer pain using a continuous quality improvement (CQI) approach to improve professionals' knowledge and skills, patient satisfaction, and to identify areas needing improvement. The sample consisted of 1210 nurse responses and 698 interviews of patients with pain during hospitalization at a major urban cancer center. The PMP provided a structure (standards), educational opportunities, and training in CQI methods. Outcome measures included a patient evaluation questionnaire and concerns checklist; nurse knowledge, attitude and barriers questionnaire; and focus groups to identify areas needing improvement. Significant improvements were found in patients' satisfaction, nurses' knowledge and attitude scores, and reductions in nurses' perceptions of barriers. Focus groups revealed the need for improved communication among disciplines about pain and better assessment of patients unable to self-report. The program met its goal of implementing the APS standards, educating nurses, and identifying "system" problems, and improving overall patient satisfaction.

Graves' disease and autoimmune factor VIII deficiency.

A patient with longstanding Hashimoto's thyroiditis who was treated with L-thyroxine at a dosage of 0.05 mg/day developed a decreased serum TSH concentration. L-Thyroxine was discontinued. Within 1 month, the patient developed mild hyperthyroidism due to Graves' disease. A hemorrhagic disorder occurred simultaneously with bleeding into muscle, joints, and skin. The bleeding disorder was identified as an acquired factor VIII deficiency due to a factor VIII inhibitor. The bleeding disorder resolved after treatment with prednisone, cyclophosphamide, and intravenous gamma globulin. Graves' disease also resolved but without specific treatment with either antithyroid drugs or radioactive iodine. The development of these two autoimmune disorders in this patient simultaneously suggests an underlying derangement in immune regulation common to both diseases.

Coping with AIDS. An approach to training and education in a therapeutic community--the Samaritan Village Program.

The emerging demographics of AIDS related disease and disorders suggests a redistribution toward the population of intravenous drug users (IVDU) and the sexual partners of IVDU's. Risk reduction strategies employing education and disease prevention appear to have had significant success within the gay community as borne out by changing epidemiologic data. This paper focuses upon one such approach that has been used in a residential therapeutic environment. It offers a practical working model that might be applicable in a variety of settings. It should be emphasized that this is not a one-step presentation of AIDS information, but rather that it is an ongoing program of AIDS education.

Development and validation of a patient needs assessment tool (PNAT) for oncology clinicians.

The Patient Needs Assessment Tool (PNAT) is an interviewer-rated scale that may be completed through a simple structured interview and screens cancer patients for potential problems in physical and psychosocial functioning. The instrument provides separate scores for physical, psychological, and social status, and can potentially clarify the types of interventions needed to address specific areas of dysfunction. Reliability and validity was tested in two studies that used prescreened patient videotapes and other materials to assess the performance of the PNAT in groups of oncology nurses, physicians, and social workers. The data demonstrate that subscale scores for the physical, psychological, and social dimensions have good inter-rater reliability and internal consistency (intraclass correlation coefficients of 0.71-0.97). Criterion and construct validity was suggested through high correlations of each subscale with the evaluation of expert raters (correlation coefficients of 0.85-0.95) and with scores on validated patient-rated instruments appropriate to the functional area. These analyses suggest that the PNAT is a valid scale for the assessment of a range of functional disturbances in the cancer population.

Significance of cell groups in voided urine.

OBJECTIVE: To determine the significance of different types of cell groups in voided urine for diagnosing transitional cell carcinoma (TCC). STUDY DESIGN: We reviewed voided urine specimens, with corresponding biopsies taken within 120 days after urine collection, for cell groups. Type and number of cell groups were correlated with the histologic diagnoses. RESULTS: Of 5,001 voided urine specimens, 134 (3%) had corresponding biopsies. Flat sheets were significantly more common in urine specimens with corresponding negative biopsies (24%) than in those with biopsies showing TCC (6%) (chi 2 P = .0032). The incidence of collared, three-dimensional cell groups was low (0-7%) and not associated with biopsy findings. Irregular, three-dimensional cell groups were more common than collared cell groups and were most common in cases with invasive TCC on biopsy (38%). While this was statistically significantly more common than in urines associated with negative biopsies (17%) (chi 2 P = .0499), it was not specific. Requiring three or more irregular cell groups did not improve discrimination between TCC and benign cases. Cell groups of any type or number were not more common in cases associated with grade 1 papillary TCC than negative biopsies. Diagnoses associated with multiple irregular, three-dimensional cell groups and a negative biopsy included medullary sponge kidney, hemorrhagic cystitis, cystitis not otherwise specified, and urolithiasis. CONCLUSION: Irregular, three-dimensional cell groups were most common in voided urine from patients with invasive TCC, but the identification of cell groups of any type in voided urine had little diagnostic utility.

Acquired drive strength as a joint function of UCS intensity and number of CS-UCS pairings: the effect of masses and distributed CS-UCS pairings.

The empirical law relating acquired drive strength, as measured by the latency of a hurdle-jump response, to UCS intensity and number of CS-UCS pairings was investigated. The effect on acquired drive strength of varying the intervals between successive CS-UCS pairings was also investigated. Ss were 150 male albino rats, 125-160 days old. The apparatus was the classically conditioned fear apparatus. Acquired drive strength was found to be curvillinearly related to UCS intensity and number of CS-UCS pairings when a 10 minute intertrial interval was used. The relationships were monotonic and hegatively accelerated. The effect of UCS intensity on acquired drive strength varied with the length of the intertrial interval. The findings of diverging functions relating UCS intensity to test trials support Spence's notion of multiplicative relationship between habit strength (sHr) and drive (d) in the determination of performance in aversive conditioning.

Stimulus compounding in classical fear conditioning.

The effect of stimulus compounding in classical conditioning was investigated by conditioning one group of rats to a compound CS consisting of a buzzer and light and then conditioning separate groups of rats to the individual elements of the compound CS. On hurdle-jump test trials, the group of Ss conditioned to the compound CS performed better than Ss conditioned to the elements of the compound. Strength of conditioning to each of the elements of the compound CS was about equal. There was some evidence of a summation effect resulting from conditioning to the compound CS. Strength of conditioning to the compound CS was somewhat greater than the sum of the response strengths conditioned to the elements of the compound CS.

[Value of high-resolution computed tomography in evaluating cervical herniated disks]. / Intérêt de la tomodensitométrie à haute résolution dans l'évaluation des hernies discales cervicales.

Previous difficulties in the diagnosis of cervical disk hernia were related to lack of non-invasive imaging techniques, but the gap has now been filled by CT scan imaging. A total of 442 patients with pains in neck, shoulder or arm were referred for a CT scan to exclude a cervical disk hernia. Of the group studied, 2% were found to have a herniated disk, 16% a lateral hernia and 9% combined lateral hernia-narrow cervical canal due to concomitant arthrotic changes. Assessment of correlation between CT scan images and myelographic and surgical findings indicated that CT scan imaging is a very precise, non-invasive method for investigation of cervical disk hernia.