6,023 research outputs found
A Statistical Analysis of the Solar Phenomena Associated with Global EUV Waves
Solar eruptions are the most spectacular events in our solar system and are
associated with many different signatures of energy release including solar
flares, coronal mass ejections, global waves, radio emission and accelerated
particles. Here, we apply the Coronal Pulse Identification and Tracking
Algorithm (CorPITA) to the high cadence synoptic data provided by the Solar
Dynamic Observatory (SDO) to identify and track global waves observed by SDO.
164 of the 362 solar flare events studied (45%) are found to have associated
global waves with no waves found for the remaining 198 (55%). A clear linear
relationship was found between the median initial velocity and the acceleration
of the waves, with faster waves exhibiting a stronger deceleration (consistent
with previous results). No clear relationship was found between global waves
and type II radio bursts, electrons or protons detected in-situ near Earth.
While no relationship was found between the wave properties and the associated
flare size (with waves produced by flares from B to X-class), more than a
quarter of the active regions studied were found to produce more than one wave
event. These results suggest that the presence of a global wave in a solar
eruption is most likely determined by the structure and connectivity of the
erupting active region and the surrounding quiet solar corona rather than by
the amount of free energy available within the active region.Comment: 33 pages, 6 figures, 1 table. Accepted for publication in Solar
Physic
The whole truth and nothing but the truth: the need for full reporting of randomised trials.
The use of cardiac output monitoring to guide fluid and inotropic therapy in surgical patients has remained a controversial topic for more than 40 years. The reasons for this are numerous and complex, but key amongst them is the interplay between poor research methodology and the likely selective reporting of randomised trials. In this issue of Perioperative Medicine, we find a very unusual report, one which describes a randomised trial stopped for futility after the recruitment of only a small proportion of the target patient sample (Jammer et al. Periop Med). The authors offer no statistical analysis of their findings but simply an explanation of what went wrong. On the face of it, this exercise would seem to offer little of value to the general reader. How can publication of the findings of an unsuccessful trial contribute to the evidence base on this topic? To understand this, we must delve a little deeper into the evidence and see how these trials were designed
Dopexamine can attenuate the inflammatory response and protect against organ injury in the absence of significant effects on hemodynamics or regional microvascular flow
This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
Predicting the sound insulation of lightweight sandwich panels
The sound insulation of three sandwich panels was modelled using simple sound insulation prediction methods, but the agreement between theory and experiment was not very good. The effective Young's modulus was determined over a wide frequency from the resonant frequencies of three beams of different lengths. The effective Young's modulus was found to reduce with increasing frequency as has been predicted in the literature. This decrease is due to the core starting to shear rather than bend because its Young's modulus is much less than the Young's moduli of the skins. Unfortunately the agreement between theory and experiment was still not very good. This is because many of the prediction frequencies occur in the critical frequency dip because of the variation of the Young's modulus with frequency
Hsc70-induced changes in clathrin-auxilin cage structure suggest a role for clathrin light chains in cage disassembly
The molecular chaperone, Hsc70, together with its co-factor, auxilin, facilitates the ATP-dependent removal of clathrin during clathrin-mediated endocytosis in cells. We have used cryo-electron microscopy to determine the 3D structure of a complex of clathrin, auxilin401-910 and Hsc70 at pH 6 in the presence of ATP, frozen within 20 seconds of adding Hsc70 in order to visualize events that follow the binding of Hsc70 to clathrin and auxilin before clathrin disassembly. In this map, we observe density beneath the vertex of the cage that we attribute to bound Hsc70. This density emerges asymmetrically from the clathrin vertex, suggesting preferential binding by Hsc70 for one of the three possible sites at the vertex. Statistical comparison with a map of whole auxilin and clathrin previously published by us reveals the location of statistically significant differences which implicate involvement of clathrin light chains in structural rearrangements which occur after Hsc70 is recruited. Clathrin disassembly assays using light scattering suggest that loss of clathrin light chains reduces the efficiency with which auxilin facilitates this reaction. These data support a regulatory role for clathrin light chains in clathrin disassembly in addition to their established role in regulating clathrin assembly
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Chronic thoracic hemisection spinal cord injury in adult rats induces a progressive decline in transmission from uninjured fibers to lumbar motoneurons
Although most spinal cord injuries are anatomically incomplete, only limited functional recovery has been observed in people and rats with partial lesions. To address why surviving fibers cannot mediate more complete recovery, we evaluated the physiological and anatomical status of spared fibers after unilateral hemisection (HX) of thoracic spinal cord in adult rats. We made intracellular and extracellular recordings at L5 (below HX) in response to electrical stimulation of contralateral white matter above (T6) and below (L1) HX. Responses from T6 displayed reduced amplitude, increased latency and elevated stimulus threshold in the fibers across from HX, beginning 1-2 weeks after HX. Ultrastructural analysis revealed demyelination of intact axons contralateral to the HX, with a time course similar to the conduction changes. Behavioral studies indicated partial recovery which arrested when conduction deficits began. These findings suggest a chronic pathological state in intact fibers and necessity for prompt treatment to minimize it
Subretinal Fluid in Eyes with Active Ocular Toxoplasmosis Observed Using Spectral Domain Optical Coherence Tomography
Purpose To describe the clinical finding of subretinal fluid (SRF) in the
posterior pole by spectral domain optical coherence tomography (SD-OCT) in
eyes with active ocular toxoplasmosis (OT). Design Retrospective case series.
Participants Thirty-eight eyes from 39 patients with active OT. Methods Eyes
with active OT which underwent SD-OCT were reviewed. SRFs in the posterior
pole were further analyzed. Main Outcome Measures Presence of SRF; its
accompanying features, e.g. retinal necrosis, cystoid macular edema (CME),
choroidal neovascularization (CNV); and longitudinal changes of SRF, including
maximum height and total volume before and after treatment. Results SRF
presented in 45.5% (or 15/33) of eyes with typical active OT and in 51.3% (or
20/39) of eyes with active OT. The mean maximum height and total volume of SRF
were 161.0 (range: 23–478) µm and 0.47 (range: 0.005–4.12) mm3, respectively.
For 12 eyes with SRF related to active retinal necrosis, SRF was observed with
complete absorption after conventional anti-toxoplasmosis treatment. The mean
duration for observation of SRF clearance was 33.8 (range: 7–84) days. The
mean rate of SRF clearance was 0.0128 (range: 0.0002–0.0665) mm3/day.
Conclusions SRF (i.e., serous retinal detachment) is a common feature in
patients with active OT when SD-OCT is performed. The majority of SRF was
associated with retinal necrosis and reacted well to conventional therapy,
regardless of total fluid volume. However, SRF accompanying with CME or CNV
responded less favorably or remained refractory to conventional or combined
intravitreal treatment, even when the SRF was small in size
Some Like It Fat: Comparative Ultrastructure of the Embryo in Two Demosponges of the Genus Mycale (Order Poecilosclerida) from Antarctica and the Caribbean
0000-0002-7993-1523© 2015 Riesgo et al. This is an open access article distributed under the terms of the Creative Commons Attribution License [4.0], which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The attached file is the published version of the article
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