241 research outputs found
Visual Loss in Neuro-Ophthalmology
Optic neuropathy is damage to the optic nerve from any cause. Damage and death of these nerve cells lead to characteristic features of optic neuropathy. The main symptom is loss of vision (visual acuity and visual field damages), with colors appearing subtly washed out in the affected eye. The diagnosis is made on clinical examination. The history often points to the possible etiology of the optic neuropathy. In most of the cases, one eye is affected but it could be both. A rapid onset is typical of demyelinating, inflammatory, ischemic, and traumatic causes. A gradual course points to compressive, toxic/nutritional, and hereditary causes. The classic clinical signs of optic neuropathy are visual acuity and field defects, dyschromatopsia, and abnormal pupillary response. There are ancillary investigations that can support the diagnosis of optic neuropathy. Visual field testing, neuroimaging of the brain and orbit are essential in many optic neuropathies including demyelinating and compressive. In the last decade, increase of use new technology for optic neuropathies evaluation including multifocal visual evoked potentials and optic coherence tomography. Long standing of optic neuropathy is described by pale optic disk or optic atrophy, which means damage and death of these nerve cells or neurons
Simulation of the electrohydrodynamic instability process used in the fabrication of hierarchic and hollow micro/nanostructures
Mapping of functionalized regions on carbon nanotubes by scanning tunneling microscopy
Scanning tunneling microscopy (STM) gives us the opportunity to map the
surface of functionalized carbon nanotubes in an energy resolved manner and
with atomic precision. But this potential is largely untapped, mainly due to
sample stability issues which inhibit reliable measurements. Here we present a
simple and straightforward solution that makes away with this difficulty, by
incorporating the functionalized multiwalled carbon nanotubes (MWCNT) into a
few layer graphene - nanotube composite. This enabled us to measure energy
resolved tunneling conductance maps on the nanotubes, which shed light on the
level of doping, charge transfer between tube and functional groups and the
dependence of defect creation or functionalization on crystallographic
orientation.Comment: Keywords: functionalization, carbon nanotubes, few layer graphene,
STM, CITS, ST
A specific RAD51 haplotype increases breast cancer risk in Jewish non-Ashkenazi high-risk women
While the precise genes involved in determining familial breast cancer risk in addition to BRCA1/2 are mostly unknown, one strong candidate is RAD51. Jewish non-Ashkenazi women at high-risk for breast/ovarian cancer and ethnically matched controls were genotyped using four single nucleotide polymorphisms spanning the RAD51 genomic region, and the resulting haplotypes were constructed using the GERBIL algorithm. A total of 314 individuals were genotyped: 184 non-Ashkenazi high-risk women (119 with breast cancer), and 130 unaffected, average-risk ethnically matched controls. Using GEBRIL, three frequent haplotypes were constructed. One of the haplotypes (TGTA -coined haplotype 3) was present in 7.3% (19/260 haplotypes) of controls (n = 130) and in 16.8% (40/238 haplotypes) of high-risk breast cancer patients (n = 119, P = 0.001). A specific RAD51 haplotype is more prevalent among non-Ashkenazi Jewish high-risk women than in average-risk population
Singular Cucker-Smale Dynamics
The existing state of the art for singular models of flocking is overviewed,
starting from microscopic model of Cucker and Smale with singular communication
weight, through its mesoscopic mean-filed limit, up to the corresponding
macroscopic regime. For the microscopic Cucker-Smale (CS) model, the
collision-avoidance phenomenon is discussed, also in the presence of bonding
forces and the decentralized control. For the kinetic mean-field model, the
existence of global-in-time measure-valued solutions, with a special emphasis
on a weak atomic uniqueness of solutions is sketched. Ultimately, for the
macroscopic singular model, the summary of the existence results for the
Euler-type alignment system is provided, including existence of strong
solutions on one-dimensional torus, and the extension of this result to higher
dimensions upon restriction on the smallness of initial data. Additionally, the
pressureless Navier-Stokes-type system corresponding to particular choice of
alignment kernel is presented, and compared - analytically and numerically - to
the porous medium equation
Visualizing Sound, Hearing Diagrams: On the Creative Process of Syrmos by Iannis Xenakis
A salient feature of Iannis Xenakis’ compositional practices was the use of several concepts and techniques borrowed from architectural design and from scientific fields. He sometimes drew complete graphic scores preluding the transcription of his fair copy of conventional musical notation. I discuss the diagrammatical features of Xenakis’ graphic score for Syrmos: although disparate representations depend on shared image schemata and cross-modal correspondences, their respective compositional logics are dissimilar
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