573 research outputs found
Towards a scalable routing approach for mobile ad-hoc networks
The Internet is evolving towards a two-fold architecture that will comprise of traditional infrastructure based networks as well as emerging self organised autonomic peripheral networks. Such Internet peripheral networks are being termed as the Internet of things (IoT) whereby smart objects and devices will be connected together in a fully distributed fashion to provide ubiquitous services through pervasive networking. Mobile Ad hoc Networks (MANETs) is regarded as one of the pervasive self-organised networks that will play a major role in autonomic future internet communication. There are several well- known challenges to be addressed in order to enable MANET deployments of large islands of interconnected smart devices. Therefore, in this paper, we present a mathematical model based analysis of various well-known routing protocols for MANETs in order to determine the scalability of these protocols. This paper analyses the scalability of the routing protocols with respect to routing overhead required by approaches while also considering the packet delivery latency, which is an important Quality of Service (QoS) metric
The Cauchy problem for a class of two-dimensional nonlocal nonlinear wave equations governing anti-plane shear motions in elastic materials
This paper is concerned with the analysis of the Cauchy problem of a general
class of two-dimensional nonlinear nonlocal wave equations governing anti-plane
shear motions in nonlocal elasticity. The nonlocal nature of the problem is
reflected by a convolution integral in the space variables. The Fourier
transform of the convolution kernel is nonnegative and satisfies a certain
growth condition at infinity. For initial data in Sobolev spaces,
conditions for global existence or finite time blow-up of the solutions of the
Cauchy problem are established.Comment: 15 pages. "Section 6 The Anisotropic Case" added and minor changes.
Accepted for publication in Nonlinearit
Blow-up and global existence for a general class of nonlocal nonlinear coupled wave equations
We study the initial-value problem for a general class of nonlinear nonlocal
coupled wave equations. The problem involves convolution operators with kernel
functions whose Fourier transforms are nonnegative. Some well-known examples of
nonlinear wave equations, such as coupled Boussinesq-type equations arising in
elasticity and in quasi-continuum approximation of dense lattices, follow from
the present model for suitable choices of the kernel functions. We establish
local existence and sufficient conditions for finite time blow-up and as well
as global existence of solutions of the problem.Comment: 11 pages. Minor changes and added reference
Photodynamic therapy of choroidal neovascularization with enlargement of the spot size to include the feeding complex
This is a case report of a 83-year-old man with choroidal neovascularization (CNV), due to age-related macular degeneration (AMD) in his right eye. Digital fluorescein (FA) and indocyanine green angiography (ICG) were performed, which disclosed predominantly classic subfoveal CNV and a dilated and tortuous feeding complex. The visual acuity was 20/800. Anti-vascular endothelial growth factor (anti-VEGF) treatment was suggested, however, the patient was not keen to receive an intraocular injection. Modified photodynamic therapy (PDT) with spot size enlarged, to include not only the CNV lesion but the feeding complex as well, was performed. Ten days after one session of PDT, ICG showed absence of leakage from the CNV and complete occlusion of the feeding complex. The visual acuity gradually improved to 20/100 and remained stable during the following 23 months. No evidence of CNV leakage was seen in the FA and ICG during the follow up period. Adjustment of the PDT spot size to include the detectable by ICG feeding complex might be an additional option in order to close the subfoveal CNV and might be considered as an alternative to intravitreal injection of anti-VEGF in selected cases where anti-VEGF treatment is not available
Mother-child histocompatibility and risk of rheumatoid arthritis and systemic lupus erythematosus among mothers.
The study objective was to test the hypothesis that having histocompatible children increases the risk of rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), possibly by contributing to the persistence of fetal cells acquired during pregnancy. We conducted a case control study using data from the UC San Francisco Mother Child Immunogenetic Study and studies at the Inova Translational Medicine Institute. We imputed human leukocyte antigen (HLA) alleles and minor histocompatibility antigens (mHags). We created a variable of exposure to histocompatible children. We estimated an average sequence similarity matching (SSM) score for each mother based on discordant mother-child alleles as a measure of histocompatibility. We used logistic regression models to estimate odds ratios (ORs) and 95% confidence intervals. A total of 138 RA, 117 SLE, and 913 control mothers were analyzed. Increased risk of RA was associated with having any child compatible at HLA-B (OR 1.9; 1.2-3.1), DPB1 (OR 1.8; 1.2-2.6) or DQB1 (OR 1.8; 1.2-2.7). Compatibility at mHag ZAPHIR was associated with reduced risk of SLE among mothers carrying the HLA-restriction allele B*07:02 (n = 262; OR 0.4; 0.2-0.8). Our findings support the hypothesis that mother-child histocompatibility is associated with risk of RA and SLE
Towards a hybrid approach to unveil the Chimaira of neurosciences : philosophy, aperiodic activity and the neural correlates of consciousness
Contemporary theories of consciousness, although very efficient in postulating testable hypotheses, seem to either neglect its relational aspect or to have a profound difficulty in operationalizing this aspect in a measurable manner. We further argue that the analysis of periodic brain activity is inadequate to reveal consciousness’s subjective facet. This creates an important epistemic gap in the quest for the neural correlates of consciousness. We suggest a possible solution to bridge this gap, by analysing aperiodic brain activity. We further argue for the imperative need to inform neuroscientific theories of consciousness with relevant philosophical endeavours, in an effort to define, and therefore operationalise, consciousness thoroughly
Nanoscale processes during the interaction of aluminosilicate and carbonate mineral surfaces with acid mine drainage (AMD)
Depto. de Mineralogía y PetrologíaFac. de Ciencias GeológicasTRUEpu
Human pericardium graft in the management of bleb's complication performed in childhood: a case report
<p>Abstract</p> <p>Background</p> <p>To report a case with hypotony due to late leakage of the filtering bleb performed during childhood and treated surgically using human pericardium graft.</p> <p>Case Presentation</p> <p>A man with hypotony related to bleb's leakage in his right eye was presented. During his childhood trabeculectomy was performed to manage ocular hypertension due to pediatric glaucoma. Biomicroscopy revealed choroidal tissue incarcerated in the sclerectomy under the conjunctiva. Bleb revision was performed. Human pericardium graft was used to cover the sclerectomy and a new bleb with controlled outflow was created. The intraocular pressure (IOP) and Seidel test represent the main outcomes. Intraoperative and postoperative complications were recorded. Fifteen days postoperatively the IOP was of 7 mmHg and the bleb seemed to filter properly. Five months later the IOP was 9 mmHg and no complications were noticed. During the follow up time, the Seidel test was negative.</p> <p>Conclusion</p> <p>We used human pericardium graft with no complications in a case of bleb leakage performed for pediatric glaucoma.</p
Measuring individual overpotentials in an operating solid-oxide electrochemical cell
We use photo-electrons as a non-contact probe to measure local electrical
potentials in a solid-oxide electrochemical cell. We characterize the cell in
operando at near-ambient pressure using spatially-resolved X-ray photoemission
spectroscopy. The overpotentials at the interfaces between the Ni and Pt
electrodes and the yttria-stabilized zirconia (YSZ) electrolyte are directly
measured. The method is validated using electrochemical impedance spectroscopy.
Using the overpotentials, which characterize the cell's inefficiencies, we
compare without ambiguity the electro-catalytic efficiencies of Ni and Pt,
finding that on Ni H_2O splitting proceeds more rapidly than H2 oxidation,
while on Pt, H2 oxidation proceeds more rapidly than H2O splitting.Comment: corrected; Phys. Chem. Chem. Phys., 201
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