Can magnetotail reconnection produce the auroral intensities observed in the conjugate ionosphere?

[1] In a recent case study, Borg et al. (2007) reported that an inverted V structure, caused by a field-aligned potential drop of 30 kV producing very strong X-ray aurora, was found in connection with tail reconnection. However, the in situ particle measurements indicated clearly that the particles responsible for the X-ray aurora were not accelerated by the reconnection process. In this article, we report the predicted auroral intensities of thirteen reconnection events where Cluster passed through the reconnection region. For six of the events, global auroral imaging data were available and the predicted auroral intensities could be compared with the observed intensities. Our main findings are as follows: (1) Acceleration in the reconnection region is generally not sufficient to account for the observed auroral intensities. (2) Additional acceleration between the reconnection region and the ionosphere is needed to explain the auroral intensities. Although we see signatures that point toward potential drops at the flanks of bursty bulk flows (BBFs), we also find signatures of Alfvén wave accelerated electrons at 700 km and we are not able to determine the most likely acceleration mechanism. (3) The reconnection events are observed 2–14 min after substorm onset and indicate that reconnection is an expanding process observed along the poleward boundary of the aurora.publishedVersio

Sports injuries in adults: overview of clinical examination and management

A wide variety of anatomical structures can be involved in a sports injury. To return to play as soon as possible is of utmost importance to an athlete, and in order to achieve this, a correct, all-inclusive diagnosis, a well-focused treatment plan, and a management plan that strives to offer protection are essential. This article aims to give an overview of acute and overuse (chronic) sports injuries in adults, the approach to an accurate diagnosis and the management strategies that are available. A literature review was conducted of scientific journals, text and internet material, including a Medline and PubMed search. Literature was selected for its in-depth data and well-researched information. Key search terms included "acute and overuse injuries", as well as "sports injuries diagnosis and management" to address current and relevant scientific data on the examination and management of sports injuries in adults. The literature review indicated that sports injuries (both acute and overuse) are increasing in number due to the growing interest in physical activity and sport, as well as the enhanced intensity of training programmes. Adults are vulnerable to both types of sports injuries, and the age of occurrence of overuse injuries varies in competitive and non-competitive athletes. The importance of making an accurate diagnosis cannot be overemphasised. To assist the clinician in making an accurate diagnosis, a comprehensive history, physical examination and appropriate special investigations are mandatory. Familiarity with the demands of the athlete's sport may also prove useful. The approach to the management of acute and overuse injuries differs, with the emphasis in acute injuries being on treating the effect (torn, broken, displaced) and in chronic injuries on treating the cause (intrinsic or extrinsic). There have been numerous advances in the management of sports injuries, however further research is still warranted in this area. Follow-up articles will focus more in-depth on specifics with regard to clinical examination, special investigations and management options

Inverse Spectral-Scattering Problem with Two Sets of Discrete Spectra for the Radial Schroedinger Equation

The Schroedinger equation on the half line is considered with a real-valued, integrable potential having a finite first moment. It is shown that the potential and the boundary conditions are uniquely determined by the data containing the discrete eigenvalues for a boundary condition at the origin, the continuous part of the spectral measure for that boundary condition, and a subset of the discrete eigenvalues for a different boundary condition. This result extends the celebrated two-spectrum uniqueness theorem of Borg and Marchenko to the case where there is also a continuous spectru

On the Schoenberg Transformations in Data Analysis: Theory and Illustrations

The class of Schoenberg transformations, embedding Euclidean distances into higher dimensional Euclidean spaces, is presented, and derived from theorems on positive definite and conditionally negative definite matrices. Original results on the arc lengths, angles and curvature of the transformations are proposed, and visualized on artificial data sets by classical multidimensional scaling. A simple distance-based discriminant algorithm illustrates the theory, intimately connected to the Gaussian kernels of Machine Learning

Development and Validity of the Rating-of-Fatigue Scale

Objective: The purpose of these experiments was to develop a rating-of-fatigue (ROF) scale capable of tracking the intensity of perceived fatigue in a variety of contexts. Methods: Four experiments were carried out. The first provided the evidential basis for the construction of the ROF scale. The second tested the face validity of the ROF, and the third tested the convergent and divergent validity of the ROF scale during ramped cycling to exhaustion and 30 min of resting recovery. The final experiment tested the convergent validity of the ROF scale with time of day and physical activity (accelerometer counts) across a whole week. Results: Modal selections of descriptions and diagrams at different levels of exertion and recovery were found during Experiment 1 upon which the ROF scale was constructed and finalised. In Experiment 2, a high level of face validity was indicated, in that ROF was reported to represent fatigue rather than exertion. Descriptor and diagrammatic elements of ROF reportedly added to the coherence and ease of use of the scale. In Experiment 3, high convergence between ROF and various physiological measures were found during exercise and recovery (heart rate, blood lactate concentration, oxygen uptake, carbon dioxide production, respiratory exchange ratio and ventilation rate were all P < 0.001). During ramped cycling to exhaustion ROF and RPE did correspond (P < 0.0001) but not during recovery, demonstrating discriminant validity. Experiment 4 found ROF to correspond with waking time during each day (Mon–Sun all P < 0.0001) and with physical activity (accelerometer count) (Mon–Sun all P < 0.001). Conclusions: The ROF scale has good face validity and high levels of convergent validity during ramped cycling to exhaustion, resting recovery and daily living activities. The ROF scale has both theoretical and applied potential in understanding changes in fatigue in a variety of contexts

Intense Synaptic Activity Enhances Temporal Resolution in Spinal Motoneurons

In neurons, spike timing is determined by integration of synaptic potentials in delicate concert with intrinsic properties. Although the integration time is functionally crucial, it remains elusive during network activity. While mechanisms of rapid processing are well documented in sensory systems, agility in motor systems has received little attention. Here we analyze how intense synaptic activity affects integration time in spinal motoneurons during functional motor activity and report a 10-fold decrease. As a result, action potentials can only be predicted from the membrane potential within 10 ms of their occurrence and detected for less than 10 ms after their occurrence. Being shorter than the average inter-spike interval, the AHP has little effect on integration time and spike timing, which instead is entirely determined by fluctuations in membrane potential caused by the barrage of inhibitory and excitatory synaptic activity. By shortening the effective integration time, this intense synaptic input may serve to facilitate the generation of rapid changes in movements

Extracorporeal cellular therapy (ELAD) in severe alcoholic hepatitis: A multinational, prospective, controlled, randomized trial.

Severe alcoholic hepatitis (sAH) is associated with a poor prognosis. There is no proven effective treatment for sAH, which is why early transplantation has been increasingly discussed. Hepatoblastoma-derived C3A cells express anti-inflammatory proteins and growth factors and were tested in an extracorporeal cellular therapy (ELAD) study to establish their effect on survival for subjects with sAH. Adults with sAH, bilirubin ≥8 mg/dL, Maddrey\u27s discriminant function ≥ 32, and Model for End-Stage Liver Disease (MELD) score ≤ 35 were randomized to receive standard of care (SOC) only or 3-5 days of continuous ELAD treatment plus SOC. After a minimum follow-up of 91 days, overall survival (OS) was assessed by using a Kaplan-Meier survival analysis. A total of 203 subjects were enrolled (96 ELAD and 107 SOC) at 40 sites worldwide. Comparison of baseline characteristics showed no significant differences between groups and within subgroups. There was no significant difference in serious adverse events between the 2 groups. In an analysis of the intent-to-treat population, there was no difference in OS (51.0% versus 49.5%). The study failed its primary and secondary end point in a population with sAH and with a MELD ranging from 18 to 35 and no upper age limit. In the prespecified analysis of subjects with MELD \u3c 28 (n = 120), ELAD was associated with a trend toward higher OS at 91 days (68.6% versus 53.6%; P = .08). Regression analysis identified high creatinine and international normalized ratio, but not bilirubin, as the MELD components predicting negative outcomes with ELAD. A new trial investigating a potential benefit of ELAD in younger subjects with sufficient renal function and less severe coagulopathy has been initiated. Liver Transplantation 24 380-393 2018 AASLD

The structural and geochemical evolution of the continental crust: Support for the oceanic plateau model of continental growth

The problem of the origin of the continental crust can be resolved into two fundamental questions: (1) the location and mechanisms of initial mantle extraction of the primitive crust and (2) the processes by which this primitive crust is converted into the continental crust that presently exists. We know that Archean continental crust is compositionally distinct from younger continental crust. Archean magmatism was dominantly bimodal, mafic thoeleiitic plus dacitic, heavy rare earth element depleted, in contrast to the dominantly unimodal, roughly andesitic calc-alkaline magmatism on younger crust [Taylor and McLennan, 1985; Condie, 1989]. The problem is whether these compositional differences are primarily due to different mechanisms of crustal extraction from the mantle or to different mechanisms of differentiation and alteration of newly formed continental crust