481 research outputs found
Bilateral Internuclear Ophthalmoplegia in a Patient with Devic's Neuromyelitis Optica
An unusual presentation of Devic's neuromyelitis optica (NMO) disease associated with bilateral internuclear ophthalmoplegia (INO) is described. A 32-year-old pregnant patient was diagnosed with NMO. First symptoms were headache and sudden visual loss in her right eye (RE). Eighteen months ago, she reported other neurologic symptoms such as paresthesia. Based on her visual field, fundoscopy and Ishihara test, she was diagnosed with retrobulbar neuritis of the RE. After delivery, new neurologic symptoms resembling transverse myelitis appeared. She was treated with methylprednisolone and plasmapheresis, which improved her visual acuity; however, a sudden bilateral INO appeared, with adduction defect and nystagmus with abduction in both eyes. No improvement was obtained after treatment with azathioprine and rituximab. Paresis of the legs and the right arm persisted, but double vision and OIN gradually disappeared. At the end, the patient had a residual exophoria in the RE and nystagmus with abduction in the left eye. Prevalence of NMO is lower than one case per one million inhabitants, and it is not likely to affect the encephalic trunk; furthermore, bilateral INO in NMO is rare. Two major criteria and at least two of the three minor ones are required to confirm a NMO diagnosis, and our patient fulfilled these diagnosis criteria
On the oxy-combustion of lignite and corn stover in a lab-scale fluidized bed reactor
This paper addresses an experimental investigation concerning oxy-combustion of coal and biomass in a lab-scale fluidized bed reactor. While co-firing has been widely studied under conventional air conditions, few experiences are available to date for O2/CO2 atmospheres. The research is focused on SO2 and NOx emissions, along with the deposition rates and ashes mineralogy. The influences of the atmosphere (air vs. 30/70% O2/CO2), the coal-to-biomass energy input ratio (80/20%, 90/10%), the chlorine mass fraction in the biomass (0.35%, 1%, 2%) and the Ca:S mole ratio (2.5, 4) are reported and discussed in the paper, for two specific fuels: high sulfur lignite and high chlorine corn stover. Concerning SO2 emissions a correlation among the sulfur and the chlorine contents is clearly detected, being affected by the direct desulfurization mechanism occurring under oxy-firing conditions. The single effect of the chlorine content is found to be almost 1.5% of the desulfurization efficiency. NOx emissions are otherwise more dependent on oxygen excess and CO concentration in the reactor, rather than the fuel share or the chlorine supplied. Thick deposition is only detected when chlorine content in the corn is 2%. Potassium aluminosilication is found to be enhanced in comparison to potassium sulfation under oxy-firing, especially for the highest Ca:S mole ratio: observed aluminosilication is five times higher when Ca:S ratio is increased from 2.5 to 4. A significant enrichment in iron is also detected for the fly ash composition, with an increase of 30–50% in comparison to air combustion
Paleomagnetism from Deception Island (South Shetlands archipelago, Antarctica), new insights into the interpretation of the volcanic evolution using a geomagnetic model
Deception Island shows the most recent exposed active volcanism in the northern boundary of the Bransfield Trough. The succession of the volcanic sequence in the island is broadly divided into pre- and post-caldera collapse units although a well-constrained chronological identification of the well-defined successive volcanic episodes is still needed. A new paleomagnetic investigation was carried out on 157 samples grouped in 20 sites from the volcanic deposits of Deception Island (South Shetlands archipelago, Antarctic Peninsula region) distributed in: (1) volcanic breccia (3 sites) and lavas (2 sites) prior to the caldera collapse; (2) lavas emplaced after the caldera collapse (10 sites); and (3) dikes cutting pre- and the lower- most post-caldera collapse units (5 sites). The information revealed by paleomagnetism provides new data about the evolution of the multi-episodic volcanic edifice of this Quaternary volcano, suggesting that the present-day position of the volcanic materials is close to their original emplace- ment position. The new data have been combined with previous paleomagnetic results in order to tentatively propose an age when comparing the paleomagnetic data with a global geomagnetic model. Despite the uncertainties in the use of averaged paleomagnetic data per volcanic units, the new data in combination with tephra occurrences noted elsewhere in the region suggest that the pre-caldera units (F1 and F2) erupted before 12,000 year BC, the caldera collapse took place at about 8300 year BC, and post-cal- dera units S1 and S2 are younger than 2000 year BC
T-Wave Morphology Restitution Predicts Sudden Cardiac Death in Patients With Chronic Heart Failure
BACKGROUND: Patients with chronic heart failure are at high risk of sudden cardiac death (SCD). Increased dispersion of repolarization restitution has been associated with SCD, and we hypothesize that this should be reflected in the morphology of the T-wave and its variations with heart rate. The aim of this study is to propose an electrocardiogram (ECG)-based index characterizing T-wave morphology restitution (TMR), and to assess its association with SCD risk in a population of chronic heart failure patients. METHODS AND RESULTS: Holter ECGs from 651 ambulatory patients with chronic heart failure from the MUSIC (MUerte Súbita en Insuficiencia Cardiaca) study were available for the analysis. TMR was quantified by measuring the morphological variation of the T-wave per RR increment using time-warping metrics, and its predictive power was compared to that of clinical variables such as the left ventricular ejection fraction and other ECG-derived indices, such as T-wave alternans and heart rate variability. TMR was significantly higher in SCD victims than in the rest of patients (median 0.046 versus 0.039, P<0.001). When TMR was dichotomized at TMR=0.040, the SCD rate was significantly higher in the TMR≥0.040 group (P<0.001). Cox analysis revealed that TMR≥0.040 was strongly associated with SCD, with a hazard ratio of 3.27 (P<0.001), independently of clinical and ECG-derived variables. No association was found between TMR and pump failure death. CONCLUSIONS: This study shows that TMR is specifically associated with SCD in a population of chronic heart failure patients, and it is a better predictor than clinical and ECG-derived variables
Understanding how a smoking cessation intervention changes beliefs, self-efficacy, and intention to quit:a secondary analysis of a pragmatic randomized controlled trial
Improved Orbital Constraints and H Photometric Monitoring of the Directly Imaged Protoplanet Analog HD 142527 B
Companions embedded in the cavities of transitional circumstellar disks have
been observed to exhibit excess luminosity at H, an indication that
they are actively accreting. We report 5 years (2013-2018) of monitoring of the
position and H excess luminosity of the embedded, accreting low-mass
stellar companion HD 142527 B from the MagAO/VisAO instrument. We use pyklip, a
python implementation of the Karhounen-Loeve Image Processing algorithm, to
detect the companion. Using pyklip forward modeling, we constrain the relative
astrometry to precision and achieve sufficient photometric
precision ( error) to detect changes in the H
contrast of the companion over time. In order to accurately determine the
relative astrometry of the companion, we conduct an astrometric calibration of
the MagAO/VisAO camera against 20 years of Keck/NIRC2 images of the Trapezium
cluster. We demonstrate agreement of our VisAO astrometry with other published
positions for HD 142527 B, and use orbitize! to generate a posterior
distribution of orbits fit to the relative astrometry of HD 142527 B. Our data
suggest that the companion is close to periastron passage, on an orbit
significantly misinclined with respect to both the wide circumbinary disk and
the recently observed inner disk encircling HD 142527 A. We translate observed
H-alpha contrasts for HD 142527 B into mass accretion rate estimates on the
order of . Photometric
variation in the H-alpha excess of the companion suggests that the accretion
rate onto the companion is variable. This work represents a significant step
towards observing accretion-driven variability onto protoplanets, such as PDS
70 b\&c.Comment: Accepted to the Astronomical Journal. 32 pages, 16 figures, 8 tables,
4 appendice
Full Connectivity: Corners, edges and faces
We develop a cluster expansion for the probability of full connectivity of
high density random networks in confined geometries. In contrast to percolation
phenomena at lower densities, boundary effects, which have previously been
largely neglected, are not only relevant but dominant. We derive general
analytical formulas that show a persistence of universality in a different form
to percolation theory, and provide numerical confirmation. We also demonstrate
the simplicity of our approach in three simple but instructive examples and
discuss the practical benefits of its application to different models.Comment: 28 pages, 8 figure
Differential study of retinal thicknesses in the eyes of Alzheimer’s patients, multiple sclerosis patients and healthy subjects
Multiple sclerosis (MS) and Alzheimer’s disease (AD) cause retinal thinning that is detectable in vivo using optical coherence tomography (OCT). To date, no papers have compared the two diseases in terms of the structural differences they produce in the retina. The purpose of this study is to analyse and compare the neuroretinal structure in MS patients, AD patients and healthy subjects using OCT. Spectral domain OCT was performed on 21 AD patients, 33 MS patients and 19 control subjects using the Posterior Pole protocol. The area under the receiver operating characteristic (AUROC) curve was used to analyse the differences between the cohorts in nine regions of the retinal nerve fibre layer (RNFL), ganglion cell layer (GCL), inner plexiform layer (IPL) and outer nuclear layer (ONL). The main differences between MS and AD are found in the ONL, in practically all the regions analysed (AUROCFOVEAL = 0.80, AUROCPARAFOVEAL = 0.85, AUROCPERIFOVEAL = 0.80, AUROC_PMB = 0.77, AUROCPARAMACULAR = 0.85, AUROCINFERO_NASAL = 0.75, AUROCINFERO_TEMPORAL = 0.83), and in the paramacular zone (AUROCPARAMACULAR = 0.75) and infero-temporal quadrant (AUROCINFERO_TEMPORAL = 0.80) of the GCL. In conclusion, our findings suggest that OCT data analysis could facilitate the differential diagnosis of MS and AD
Datación de la evolución volcánica combinando datos paleomagnéticos y modelización geomagnética: Isla Decepción (Islas Shetland del Sur, Antártida).
La combinación de 20 nuevas estaciones de paleomagnetismo, con 17 estaciones previas y un modelo geomagnético ha permitido establecer la evolución multiepisódica del edificio volcánico cuaternario de la Isla Decepción (Antártida). Se han analizado tres estaciones en brechas volcánicas y dos estaciones en lavas pertenecientes a los materiales extruidos con anterioridad al colapso de la caldera. Entre los materiales extruidos posteriormente al colapso de la caldera se han analizado 10 estaciones en lavas y cinco estaciones en diques que cortan a los materiales pre- y la base de los post-colapso de caldera. A pesar de la incertidumbre por el uso de promedios de datos paleomagnéticos, la correlación con el modelo geomagnético y la existencia de tefras a escala regional permiten establecer que las unidades pre-colapso de caldera (F1 y F2) son anteriores a 12.000 a AC, mientras que la caldera colapsó en torno a los 8300 a AC y las unidades posteriores al colapso de la caldera (S1 y S2) han extruido con posterioridad a 2000 a AC.
The combination of 20 new paleomagnetic sites with 17 previous sites and a geomagnetic model has allowed establishing the multi-episodic evolution of the Quaternary volcanic edifice of Deception Island (Antarctica). Paleomagnetic analyses have been carried out in three sites from volcanic breccia and two sites from lavas of the pre- caldera collapse units. Among the post-caldera collapse units, 10 sites in lavas have been analyzed in addition to 5 sites in dikes that intrude pre- and the lower part of the post-caldera collapse units. Despite the uncertainty of using averages of paleomagnetic data, the correlation with the geomagnetic model and tephra layers occurrences allow establishing that the pre-caldera collapse (F1 and F2) are older than 12,000 yr BC, while the caldera collapse occurred at about 8300 yr BC and the post-caldera collapse units (S1 and S2) deposited after 2000 yr BC
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