16,656 research outputs found
Limiting velocities as running parameters and superluminal neutrinos
In the context of theories where particles can have different limiting
velocities, we review the running of particle speeds towards a common limiting
velocity at low energy. Motivated by the recent OPERA experimental results, we
describe a model where the neutrinos would deviate from the common velocity by
more than do other particles in the theory, because their running is slower due
to weaker interactions.Comment: 5 pages, 3 figure
Availability analysis of terrestrial free space optical (FSO) link using visibility data measured in tropical region
Haze and rain are the most impairments factors to free space optical (FSO) links. These weather conditions limit the visibility, and thereby causes high attenuation of the optical signal. This high attenuation reduces the availability performance of the FSO link. This study evaluates the performance of a terrestrial FSO link under tropical climate conditions. The performance analysis is evaluate over 5 km link distance. The cumulative distribution function (CDF) of the received signal to noise ratio (SNR) is used to study the outage performance of the FSO link under haze conditions. The performance analysis is based on three years measured visibility data in Malaysia. Based on the statistical analysis, link availability of 99.99% can be achieved for 37.44 dB SNR over 1 km link distance. Carrier class availability âfive nineâ can be achieved for 20 dBm transmission power using 1550 nm wavelength
Support Vector Regression Based S-transform for Prediction of Single and Multiple Power Quality Disturbances
This paper presents a novel approach using Support Vector Regression (SVR) based
S-transform to predict the classes of single and multiple power quality disturbances in a
three-phase industrial power system. Most of the power quality disturbances recorded in an
industrial power system are non-stationary and comprise of multiple power quality
disturbances that coexist together for only a short duration in time due to the contribution
of the network impedances and types of customersâ connected loads. The ability to detect
and predict all the types of power quality disturbances encrypted in a voltage signal is vital
in the analyses on the causes of the power quality disturbances and in the identification of
incipient fault in the networks. In this paper, the performances of two types of SVR based
S-transform, the non-linear radial basis function (RBF) SVR based S-transform and the
multilayer perceptron (MLP) SVR based S-transform, were compared for their abilities in
making prediction for the classes of single and multiple power quality disturbances. The
results for the analyses of 651 numbers of single and multiple voltage disturbances gave
prediction accuracies of 86.1% (MLP SVR) and 93.9% (RBF SVR) respectively.
Keywords: Power Quality, Power Quality Prediction, S-transform, SVM, SV
Evaluating the Baluti Formation at Sararu village, Ora Anticline, Iraqi Kurdistan : a stratigraphic and geochemical approach
Open access through Springer Compact Agreement Acknowledgements The authors would like to thank Colin Taylor and Walter Ritchie from University of Aberdeen for their technical support and assistance with laboratory work. We would also like to thank Mr. Omer Kamil Ali, the Head of the Qumri village, for providing accommodation during fieldwork.Peer reviewedPublisher PD
Structural Efficiency of Steel Stiffening Deck Systems in Suspension Bridges Due to Gravity Loads
In this paper, suspended stiffened decks in suspension bridges are considered. Three
steel deck-stiffening systems are compared structurally; the plate girder, the box girder
and the stiffening truss. A three-span continuous suspension bridge model is considered.
Analysis is made by the second order non-linear deflection theory in its linearized form.
Developed software is used for the analysis to determine the induced tension in the
cable, moments, shears and deflections of the girders for any general live load case.
AASHTO criteria for steel girders are adopted. AASHTO highway live loads -HL 93-
are applied to Khartoum-Tuti Suspension Bridge in Khartoum, Sudan for each type of
the stiffening systems. Ten load cases are considered and discussed. Results have shown
that the most efficient type to resist gravity loads is the stiffening truss, followed by the
box girder and last is the plate girde
Invasive fungal infections and patients with malignancies in upper Egypt
The incidence of invasive fungal infections has increased considerably in recent years. The aim of this study was to present a suitable early diagnostic procedure in immune compromised patients, using detection of fungal infection of urine samples collected from 33 patients with malignancies (from 2-89 years old), during the period from December 2012 to February 2014, from South Egypt. Fifty-three fungal species representing 14 genera were collected during this investigation from urine samples on Sabouraoudâs Dextrose Chloramphenicol Agar (46 species and 12 genera) and Rose Bengal Chloramphenicol Agar media (41 species and 11 genera). Aspergillus (16 species), Penicillium (14 species), Yeasts (5 species) and Cladosporium (5 species) contributed the broadest spectra of species in all samples tested on two types of media used. Other species were represented by 13 species belonging to 10 genera. The results indicate that immune compromised patient is a suitable habitat for the growth and sporulation of different groups of fungi, both saprophytic and pathogenic. A variety of types of filamentous fungi were obtained from malignancies patients. Immunosuppressant patientâs exposure for fungal infection so should be in especial care from food, drinking and air.
Published by the International journal of Microbiology and Mycology (IJMM
Folliculostellate cells in pituitary pars distalis of male viscacha: immunohistochemical, morphometric and ultrastructural study
Folliculostellate cells (FSC) have been reported in pituitary of several mammalian species. FSC morphology and secreted substances have been instrumental to the understanding of their function. The purpose of this work was to perform an immunohistochemical, morphometric and ultrastructural study of the pituitary pars distalis FSC in adult male viscacha and to analyze their relation with hormone secreting cells. Immunohistochemistry and image analysis were carried out in different sectors of the gland, from the middle (sector 1) to the glandular periphery (sector 5). Transmission electron microscopy with lanthanum as electrodense tracer was used. FSC formed follicles with PAS-positive colloid inside. They expressed S-100 protein mainly in both nucleus and cytoplasm. FSC were stellate-like in shape and exhibited short cytoplasmic processes that contacted with blood vessels and endocrine cells. In addition, some follicular colloids were immunostained with anti-S-100 protein. A few FSC were immunostained with anti-glial fibrillary acidic protein (GFAP) and anti-vimentin. The morphometric parameters analyzed (percentages of S-100-positive total, cellular and colloidal areas) increased from sector 1 to sector 3 and then decreased to sector 5. Hormone secreting cells, mainly lactotrophs, gonadotrophs and corticotrophs were associated with FSC and follicles. The ultrastructural study demonstrated that FSC developed junctional complexes and desmosomes between their lateral membranes. Lanthanum freely penetrated the spaces between granulated cells and FSC, but did not penetrate into the follicular lumen. In conclusion: 1) the differential expression of S-100 protein, GFAP and vimentin may indicate different physiological stages of FSC; 2) the expression of these proteins suggests a neuroectodermic origin of these cells; 3) FSC spatial distribution, association with endocrine cells, and the generation of an intercellular communication network suggest that FSC are involved in the pituitary pars distalis paracrine regulation of the viscacha
ALMA observations of the variable 12CO/13CO ratio around the asymptotic giant branch star R Sculptoris
[abridged] The 12CO/13CO ratio is often used as a measure of the 12C/13C
ratio in the circumstellar environment, carrying important information about
the stellar nucleosynthesis. External processes can change the 12CO and 13CO
abundances, and spatially resolved studies of the 12CO/13CO ratio are needed to
quantify the effect of these processes on the globally determined values.
Additionally, such studies provide important information on the conditions in
the circumstellar environment. The detached-shell source R Scl, displaying CO
emission from recent mass loss, in a binary-induced spiral structure as well as
in a clumpy shell produced during a thermal pulse, provides a unique laboratory
for studying the differences in CO isotope abundances throughout its recent
evolution. We observed both the 12CO(J=3-2) and the 13CO(J=3-2) line using
ALMA. We find significant variations in the 12CO/13CO intensity ratios and
consequently in the abundance ratios. The average CO isotope abundance ratio is
at least a factor three lower in the shell (~19) than that in the present-day
(60). Additionally, variations in the ratio of more
than an order of magnitude are found in the shell itself. We attribute these
variations to the competition between selective dissociation and isotope
fractionation in the shell, of which large parts cannot be warmer than ~35 K.
However, we also find that the 12CO/13CO ratio in the present-day mass loss is
significantly higher than the 12C/13C ratio determined in the stellar
photosphere from molecular tracers (~19). The origin of this discrepancy is
still unclear, but we speculate that it is due to an embedded source of
UV-radiation that is primarily photo-dissociating 13CO. This radiation source
could be the hitherto hidden companion. Alternatively, the UV-radiation could
originate from an active chromosphere of R Scl itself....Comment: 6 pages, 5 figures, online data available at
http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=J/A+A/556/L
Cathepsin b: a potential prognostic marker for inflammatory breast cancer
<p>Abstract</p> <p>Background</p> <p>Inflammatory breast cancer (IBC) is the most aggressive form of breast cancer. In non-IBC, the cysteine protease cathepsin B (CTSB) is known to be involved in cancer progression and invasion; however, very little is known about its role in IBC.</p> <p>Methods</p> <p>In this study, we enrolled 23 IBC and 27 non-IBC patients. All patient tissues used for analysis were from untreated patients. Using immunohistochemistry and immunoblotting, we assessed the levels of expression of CTSB in IBC versus non-IBC patient tissues. Previously, we found that CTSB is localized to caveolar membrane microdomains in cancer cell lines including IBC, and therefore, we also examined the expression of caveolin-1 (cav-1), a structural protein of caveolae in IBC versus non-IBC tissues. In addition, we tested the correlation between the expression of CTSB and cav-1 and the number of positive metastatic lymph nodes in both patient groups.</p> <p>Results</p> <p>Our results revealed that CTSB and cav-1 were overexpressed in IBC as compared to non-IBC tissues. Moreover, there was a significant positive correlation between the expression of CTSB and the number of positive metastatic lymph nodes in IBC.</p> <p>Conclusions</p> <p>CTSB may initiate proteolytic pathways crucial for IBC invasion. Thus, our data demonstrate that CTSB may be a potential prognostic marker for lymph node metastasis in IBC.</p
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