Observations of discrete magnetosonic waves off the magnetic equator

Fast mode magnetosonic waves are typically confined close to the magnetic equator and exhibit harmonic structures at multiples of the local, equatorial proton cyclotron frequency. We report observations of magnetosonic waves well off the equator at geomagnetic latitudes from −16.5°to −17.9° and L shell ~2.7–4.6. The observed waves exhibit discrete spectral structures with multiple frequency spacings. The predominant frequency spacings are ~6 and 9 Hz, neither of which is equal to the local proton cyclotron frequency. Backward ray tracing simulations show that the feature of multiple frequency spacings is caused by propagation from two spatially narrow equatorial source regions located at L ≈ 4.2 and 3.7. The equatorial proton cyclotron frequencies at those two locations match the two observed frequency spacings. Our analysis provides the first observations of the harmonic nature of magnetosonic waves well away from the equatorial region and suggests that the propagation from multiple equatorial sources contributes to these off-equatorial magnetosonic emissions with varying frequency spacings

Source of the low-altitude hiss in the ionosphere

We analyze the propagation properties of low-altitude hiss emission in the ionosphere observed by DEMETER (Detection of Electromagnetic Emissions Transmitted from Earthquake Regions). There exist two types of low-altitude hiss: type I emission at high latitude is characterized by vertically downward propagation and broadband spectra, while type II emission at low latitude is featured with equatorward propagation and a narrower frequency band above ∼fcH+. Our ray tracing simulation demonstrates that both types of the low-altitude hiss at different latitude are connected and they originate from plasmaspheric hiss and in part chorus emission. Type I emission represents magnetospheric whistler emission that accesses the ionosphere. Equatorward propagation associated with type II emission is a consequence of wave trapping mechanisms in the ionosphere. Two different wave trapping mechanisms are identified to explain the equatorial propagation of Type II emission; one is associated with the proximity of wave frequency and local proton cyclotron frequency, while the other occurs near the ionospheric density peak

Planform selection in two-layer Benard-Marangoni convection

Benard-Marangoni convection in a system of two superimposed liquids is investigated theoretically. Extending previous studies the complete hydrodynamics of both layers is treated and buoyancy is consistently taken into account. The planform selection problem between rolls, squares and hexagons is investigated by explicitly calculating the coefficients of an appropriate amplitude equation from the parameters of the fluids. The results are compared with recent experiments on two-layer systems in which squares at onset have been reported.Comment: 17 pages, 7 figures, oscillatory instability included, typos corrected, references adde

Efficacy of the "local anaesthetic injection technique" in anterior cruciate ligament reconstructions of professional soccer players

Background: There are very little data in orthopaedic literature about ACL reconstruction, without use of tourniquets. One of the alternatives to pneumatic tourniquets in ACL surgery is the "injection technique" described by Furia and Zambetti. Between 1994 and 2000, we preferred to apply this local anaesthetic technique in ACL reconstruction operations lasting more than 2. h in 576 professional athletes. Hypothesis: This technique gives more time to the senior surgeon for training resident surgeons and almost same bloodless field as visible as tourniquet usage in ACL senior surgery. Study design: Level of evidence: IV (case series, prospective study of previously collected data). Methods: In 576 cases, injections of "Solution 1" (lidocaine and epinephrine, for skin and subcutaneous injection) and "Solution 2" (bupivicaine and epinephrine, for intra-articular injection) were administered without inflating the preapplied pneumatic tourniquet. After performing a diagnostic arthroscopy or a surgical arthroscopic procedure, we reconstructed the ACL with a BTB autograft through a mini anterior arthrotomy incision. All major or minor complications due to the injections were carefully recorded. Results: The mean operation time was 165. min in patients without co-existing cartilage or meniscal pathology and 205. min in patients with co-existing pathologies. No cardiovascular complications were recorded. The bloodless field was obscured in only seven patients (1.2%). Partial wound edge cyanosis was noted in 18 patients (3%) near the graft harvesting incisions, making the overall complication rate of this "injection technique" 4.3%. Conclusion: This technique gave superior visibility as tourniquet usage in 98.8% cases and also gave more time to the surgeon for resident education. So the surgeon did not have to worry about tourniquet times. © 2015 International Society for Knowledge for Surgeons on Arthroscopy and Arthroplasty

Thermo-Mechanical Treatment Effects on Stress Relaxation and Hydrogen Embrittlement of Cold-Drawn Eutectoid Steels

The effects of the temperature and stretching levels used in the stress-relieving treatment of cold-drawn eutectoid steel wires are evaluated with the aim of improving the stress relaxation behavior and the resistance to hydrogen embrittlement. Five industrial treatments are studied, combining three temperatures (330, 400, and 460 °C) and three stretching levels (38, 50 and 64% of the rupture load). The change of the residual stress produced by the treatments is taken into consideration to account for the results. Surface residual stresses allow us to explain the time to failure in standard hydrogen embrittlement test

Statistical characteristics of ionospheric hiss waves

In this study, we use the observations of electromagnetic waves by DEMETER satellite to investigate propagation characteristics of low altitude ionospheric hiss. In an event study, intense hiss wave power is concentrated over a narrow frequency band with a central frequency that decreases as latitude decreases, which coincides to the variation of local proton cyclotron frequency fCH. The wave propagates obliquely to the background magnetic field and equatorward from high latitude region. We use about 6 years' observations to statistically study the dependence of ionospheric hiss wave power on location, local time, geomagnetic activity and season. The results demonstrate that the ionospheric hiss power is stronger on the dayside, under higher geomagnetic activity, in local summer and confined near the region where the local fCH is equal to the wave frequency. To explain the concentration of wave power, a ray tracing simulation is performed and reproduced the wave propagation process

FLASHES Survey. I. Integral Field Spectroscopy of the CGM around 48 z ≃ 2.3–3.1 QSOs

We present the pilot study of the Fluorescent Lyman-Alpha Structures in High-z Environments Survey; the largest integral field spectroscopy survey to date of the circumgalactic medium at z = 2.3–3.1. We observed 48 quasar fields with the Palomar Cosmic Web Imager to an average (2σ) limiting surface brightness of 6 × 10⁻¹⁸ erg s⁻¹ cm⁻² arcsec⁻² (in a 1'' aperture and ~20 Å bandwidth). Extended H I Lyα emission is discovered around 37/48 of the observed quasars, ranging in projected radius from 14 to 55 proper kiloparsecs (pkpc), with one nebula exceeding 100 pkpc in effective diameter. The dimming-adjusted circularly averaged surface brightness profile peaks at 1 × 10⁻¹⁵ erg s⁻¹ cm⁻² arcsec⁻² at R⊥ ~ 20 pkpc and integrated luminosities range from 0.4 to 9.4 × 10⁴³ erg s⁻¹. The emission appears to have an eccentric morphology and an average covering factor of ~30%–40% at small radii. On average, the nebular spectra are redshifted with respect to both the systemic redshift and Lyα peak of the quasar spectrum. The integrated spectra of the nebulae mostly have single- or double-peaked profiles with global dispersions ranging from 143 to 708 km s⁻¹, though the individual Gaussian components of lines with complex shapes mostly have dispersions ≤400 km s⁻¹, and the flux-weighted velocity centroids of the lines vary by thousands of km s⁻¹ with respect to the QSO redshifts. Finally, the root-mean-square velocities of the nebulae are found to be consistent with those expected from gravitational motions in dark matter halos of mass Log₁₀(M_h[M⊙]) ≃ 12.2^(+0.7)_(-1.2). We compare these results to existing surveys at higher and lower redshift

Assessment of proportion of hidden patients having symptoms of overactive bladder and why has it been hidden in female outpatients admitted to hospital

Purpose: To determine the proportion of patients with undetected symptoms of overactive bladder by using the overactive bladder-validated 8 (OAB-V8) screening questionnaire and investigate these symptoms were undetected in female patients who were hospitalized. Methods: We invited 2,250 female patients hospitalized in the Aegean region of Turkey to answer a self-administered questionnaire. The questionnaire included questions on evidence of lower urinary tract symptoms (OAB-V8), relevant medical history, and demographic data. Patients with a total OAB-V8 score ≥ 8 were defined as having OAB symptoms. Results: The proportion of patients with OAB symptoms in this study was 40.6%. Nearly 57% of the patients with OAB symptoms had not been previously admitted to any hospital for lower urinary tract symptoms (LUTS). The two most common reasons why women with OAB symptoms did not admit themselves to a hospital because of LUTS were as follows: "I did not think I had a disease" and "The symptoms did not bother me," with a response rate of 74.7%. The mean OAB-V8 scores of the patients with these two responses were significantly lower than those of the other patients (P < 0.001). Conclusions: This is the first study to demonstrate a significant proportion of women with undetected OAB symptoms. The main reasons the women did not admit themselves to a hospital were their unawareness of the disease and because the LUTS were not bothersome. Public awareness programs on this disease may resolve this problem. © 2016 Korean Continence Society

The Electric Field Detector on board the China Seismo Electromagnetic Satellite: In-Orbit Results and Validation

The aim of this work is to validate the China Seismo-Electromagnetic Satellite 01 (CSES-01) Electric Field Detector (EFD) measurements through the analysis of the instrument response to various inputs: (a) geomagnetic field variations, (b) plasma density depletions, and (c) electromagnetic signals from natural and artificial sources such as Schumann resonance and VLF (Very Low Frequency) antennas. The knowledge of the geomagnetic induced electric field vs × B (where vs is the satellite speed and B and the local magnetic field), and the plasma variations effect, described by the Orbit Motion Limited (OML) theory, are key parameters to determine the expected theoretical values of the EFD sensors potentials data. Based on the CSES on-board measurements of plasma parameters and geomagnetic field, a direct quantitative validation is presented. In addition, the electromagnetic signals detection capability is checked but only qualitatively confirmed, since the ionospheric complexity does not allow an accurate theoretical computation of waves modulation. The quantitative comparison highlights the very good agreement between observed and theoretical potentials values during average condition. Conversely, in case of strong electric fields, the OML theory shows partial inability in reproducing the actual space plasma conditions resulting in a reduced theoretical values reliability. Finally, both natural and artificial electromagnetic signals are satisfactorily identified showing a reliable sensitivity in different frequency bands