5,003 research outputs found
The fate of spiral galaxies in clusters: The star formation history of the anemic Virgo cluster galaxy NGC 4569
We present a new method for studying the star formation history of late-type cluster galaxies undergoing gas starvation or a ram pressure stripping event by combining bidimensional multifrequency observations with multizone models of galactic chemical and spectrophotometric evolution. This method is applied to the Virgo Cluster anemic galaxy NGC 4569. We extract radial profiles from recently obtained UV GALEX images at 1530 and 2310 Å, from visible and near-IR narrow (Hα) and broadband images at different wavelengths (u, B, g, V, r, i, z, J, H, and K), from Spitzer IRAC and MIPS images, and from atomic and molecular gas maps. The model in the absence of interaction (characterized by its rotation velocity and spin parameter) is constrained by the unperturbed H-band light profile and by the Hα rotation curve. We can reconstruct the observed total gas radial density profile and the light surface brightness profiles at all wavelengths in a ram pressure stripping scenario by making simple assumptions about the gas removal process and the orbit of NGC 4569 inside the cluster. The observed profiles cannot be reproduced by simply stopping gas infall, thus mimicking starvation. Gas removal is required, which is more efficient in the outer disk, inducing radial quenching in the star formation activity, as observed and reproduced by the model. This observational result, consistent with theoretical predictions that a galaxy cluster-IGM interaction is able to modify structural disk parameters without gravitational perturbations, is discussed in the framework of the origin of lenticular galaxies in cluster
Circulating Exosomal Mir21 And Mir320 In Obstructive Sleep Apnea
Rational. Epidemiological studies indicate that there may be an association between obstructive sleep apnea (OSA) and cardiovascular and metabolic diseases. Some pro-inflammatory miRs (miR-21, miR320) critical for the immune response or hypoxia are often overexpressed in cancers and atherosclerosis. Aim. To examine the expression of miR-21& miR320 in circulating exosomes from patients with OSA. Methods: From a Sleep Unit and in the frame of a long-term longitudinal cohort study we selected 65 non-smokers OSA patients (apnea-hypopnea index -AHI- 30 events/ti) and 26 age, gender and BMI-matched controls (AHI 0.85 mm. Plasma-derived exosomes were isolated by precipitation using miRCURY, , , Exosome Isolation Kit. Exosomes were characterized by transmission electron microscopy, dynamic light scattering assay and Western Blot analysis using CD63 and HSP70. Exosome total RNA was obtained using miRCURY"* RNA isolation kit. miR-21 -5p and miR-320-3p were analysed by real time quantitative PCR (RT-qPCR) using miRCURY LNA~ technology..
Study of different titanosilicate (TS-1 and ETS-10) as fillers for Mixed Matrix Membranes for CO2/CH4 gas separation applications
Three titanosilicate zeolites were used as fillers for Mixed Matrix Membranes: (i) ETS-10, TS-1 having Si/Ti=100 and (iii) TS-1 using Si/Ti=25. Zeolite samples were characterized by X-Ray Diffraction, Scanning Electron Microscopy, Atomic Emission Spectroscopy, X-Ray Photoelectron Spectroscopy, and CO2 and CH4 adsorption isotherms. TS-1 particles showed a narrow size distribution ranging from 200 nm to 400 nm. In the case of ETS-10, the size distribution was broader ranging from 400 nm to 800 nm. Mixed Matrix Membranes were prepared using Matrimid (R) polyimide as continuous phase and filler loadings of 10, 20, and 30 wt%. Membranes were characterized by Thermogravimetric Analysis, Differential Scanning Calorimetry, and Scanning Electron Microscopy. The performances was measured at 8 bars of transmembrane pressure for CO2/CH4 mixed gases system at 50/50 vol/vol. concentration. Membranes using TS-1 (Si/Ti=25) as filler showed a maximum increase of 89.1% of CO2 permeability and 23.9% increase in separation factor. In the case of TS-1 (Si/Ti=100) only permeability increased significantly, with a maximum increase of 90.1%. Regarding the ETS-10 membranes, both permeability and separation factor increased slightly with respect to the reference polymeric membrane (22.5% in CO2 permeability and 7.8% in the separation factor). In conclusion, TS-1 (Si/Ti=25) is the most suitable filler for the use in Mixed Matrix Membranes for gas separation applications among the titanosilicate studied in this work
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
Optical energies of AllnN epilayers
Optical energy gaps are measured for high-quality Al1−xInxN-on-GaN epilayers with a range of compositions around the lattice match point using photoluminescence and photoluminescence excitation spectroscopy. These data are combined with structural data to determine the compositional dependence of emission and absorption energies. The trend indicates a very large bowing parameter of 6 eV and differences with earlier reports are discussed. Very large Stokes' shifts of 0.4-0.8 eV are observed in the composition range 0.13<x<0.24, increasing approximately linearly with InN fraction despite the change of sign of the piezoelectric fiel
DEVELOPMENT OF A SCADA SYSTEM FOR ACCESS, PROCESSING AND SUPERVISION OF DATA COMING FROM A WIRELESS SENSORS NETWORK IN AGRO-ENVIRONMENTAL APPLICATIONS
Wireless sensors networks appeared in the 1970’s for military and
industrial use. They have since undergone a major evolution, particularly since the 90’s,
thanks to the improvements in wireless communications. These changes have allowed
them to participate in a wide variety of applications in different sectors such as
agriculture and environment. This paper shows the development of a SCADA application
programmed with LabVIEW® 8.6 (National Instruments), which allows management of
data received by wireless sensors networks through a friendly interface for users. For the
application shown in this paper we have worked with a MEP 510 sensors network
(Crossbow). The functionalities implemented are the following: Network configuration;
Data storage into database; Statistical processing of historical data with polynomial
adjustment and spline interpolation; Visualization by data graphics in real time and
historical data; Visualization of 2D intensity diagrams from the spatial distribution of
sensors; and Creation of a users registry system that allows, depending on the category
assigned, receiving or not access privileges in the application. As a complement we have
developed the possibility of remote access. Sensors network implemented and the
applications developed have been checked by operational tests for each functionality, as
well as sensors joining and leaving the network situations, range of variables and working
modes. The results obtained show the robustness of the SCADA application and the
limitations of wireless sensors networks operating on field conditions
Retinal and Optic Nerve Degeneration in Patients with Multiple Sclerosis Followed up for 5 Years
Purpose: To quantify retinal nerve fiber layer (RNFL) changes in patients with multiple sclerosis (MS) and healthy controls with a 5-year follow-up and to analyze correlations between disability progression and RNFL degeneration.
Design: Observational and longitudinal study.
Participants: One hundred patients with relapsing-remitting MS and 50 healthy controls.
Methods: All participants underwent a complete ophthalmic and electrophysiologic exploration and were re-evaluated annually for 5 years.
Main Outcome Measures: Visual acuity (Snellen chart), color vision (Ishihara pseudoisochromatic plates), visual field examination, optical coherence tomography (OCT), scanning laser polarimetry (SLP), and visual evoked potentials. Expanded Disability Status Scale (EDSS) scores, disease duration, treatments, prior optic neuritis episodes, and quality of life (QOL; based on the 54-item Multiple Sclerosis Quality of Life Scale score).
Results: Optical coherence tomography (OCT) revealed changes in all RNFL thicknesses in both groups. In the MS group, changes were detected in average thickness and in the mean deviation using the GDx-VCC nerve fiber analyzer (Laser Diagnostic Technologies, San Diego, CA) and in the P100 latency of visual evoked potentials; no changes were detected in visual acuity, color vision, or visual fields. Optical coherence tomography showed greater differences in the inferior and temporal RNFL thicknesses in both groups. In MS patients only, OCT revealed a moderate correlation between the increase in EDSS and temporal and superior RNFL thinning. Temporal RNFL thinning based on OCT results was correlated moderately with decreased QOL.
Conclusions: Multiple sclerosis patients exhibit a progressive axonal loss in the optic nerve fiber layer. Retinal nerve fiber layer thinning based on OCT results is a useful marker for assessing MS progression and correlates with increased disability and reduced QOL
UV properties of early-type galaxies in the Virgo cluster
We study the UV properties of a volume limited sample of early-type galaxies
in the Virgo cluster combining new GALEX far- (1530 A) and near-ultraviolet
(2310 A) data with spectro-photometric data available at other wavelengths. The
sample includes 264 ellipticals, lenticulars and dwarfs spanning a large range
in luminosity (M(B)<-15). While the NUV to optical or near-IR color magnitude
relations (CMR) are similar to those observed at optical wavelengths, with a
monotonic reddening of the color index with increasing luminosity, the (FUV-V)
and (FUV-H) CMRs show a discontinuity between massive and dwarf objects. An
even more pronounced dichotomy is observed in the (FUV-NUV) CMR. For
ellipticals the (FUV-NUV) color becomes bluer with increasing luminosity and
with increasing reddening of the optical or near-IR color indices. For the
dwarfs the opposite trend is observed. These observational evidences are
consistent with the idea that the UV emission is dominated by hot, evolved
stars in giant systems, while in dwarf ellipticals residual star formation
activity is more common.Comment: 5 pages, 2 figures, 1 table. Accepted for publication in
Astrophysical Journal Letter
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