389 research outputs found
Comparison of acute non-visual bright light responses in patients with optic nerve disease, glaucoma and healthy controls.
This study examined the effect of optic nerve disease, hence retinal ganglion cell loss, on non-visual functions related to melanopsin signalling. Test subjects were patients with bilateral visual loss and optic atrophy from either hereditary optic neuropathy (n = 11) or glaucoma (n = 11). We measured melatonin suppression, subjective sleepiness and cognitive functions in response to bright light exposure in the evening. We also quantified the post-illumination pupil response to a blue light stimulus. All results were compared to age-matched controls (n = 22). Both groups of patients showed similar melatonin suppression when compared to their controls. Greater melatonin suppression was intra-individually correlated to larger post-illumination pupil response in patients and controls. Only the glaucoma patients demonstrated a relative attenuation of their pupil response. In addition, they were sleepier with slower reaction times during nocturnal light exposure. In conclusion, glaucomatous, but not hereditary, optic neuropathy is associated with reduced acute light effects. At mild to moderate stages of disease, this is detected only in the pupil function and not in responses conveyed via the retinohypothalamic tract such as melatonin suppression
MRI/TRUS data fusion for brachytherapy
BACKGROUND: Prostate brachytherapy consists in placing radioactive seeds for
tumour destruction under transrectal ultrasound imaging (TRUS) control. It
requires prostate delineation from the images for dose planning. Because
ultrasound imaging is patient- and operator-dependent, we have proposed to fuse
MRI data to TRUS data to make image processing more reliable. The technical
accuracy of this approach has already been evaluated. METHODS: We present work
in progress concerning the evaluation of the approach from the dosimetry
viewpoint. The objective is to determine what impact this system may have on
the treatment of the patient. Dose planning is performed from initial TRUS
prostate contours and evaluated on contours modified by data fusion. RESULTS:
For the eight patients included, we demonstrate that TRUS prostate volume is
most often underestimated and that dose is overestimated in a correlated way.
However, dose constraints are still verified for those eight patients.
CONCLUSIONS: This confirms our initial hypothesis
Talaria: Continuous Drag & Drop on a Wall Display
International audienceWe present an interaction technique combining tactile actions and Midair pointing to access out-of-reach content on large displays without the need to walk across the display. Users can start through a Touch gesture on the display surface and finish Midair by pointing to push content away or inversely to retrieve a content. The technique takes advantage of wellknown semantics of pointing in human-to-human interaction.These, coupled with the semantics of proximal relations and deictic proxemics make the proposed technique very powerful as it leverages on well-understood human-human interaction modalities. Experimental results show this technique to outperform direct tactile interaction on dragging tasks. From our experience we derive four guidelines for interaction with large-scale displays
Residencia universitaria en la Universidad de Lausana, Suiza
This university residence consists, basically, of two main blocks. One contains the bedrooms, and operates in a manner that is similar to that of a hotel. The other is occupied by the hexagonally shaped restaurant, and its lower height provides a pleasant contrast to the total design. Both blocks are linked by a platform that serves as roof for the commercial zone, the offices and the laboratories.
The residence has 150 bedrooms, 3 apartments, a restaurant, a cafeteria, a music room, a reading room and the usual services.
The external and internal aspect is satisfying and correct, very simple, and is expressed in long lasting textures that are easy to maintain.Esta residencia universitaria consta, esencialmente, de dos cuerpos de edificio: uno aloja las habitaciones y funciona con régimen similar al de un hotel; y otro, ocupado por un restaurante con planta hexagonal, cuyo volumen más bajo aporta una nota graciosa al conjunto. Ambos cuerpos están unidos por una plataforma que sirve de techo a los locales comerciales, despachos y laboratorios creados.
La residencia comprende: 150 habitaciones, 3 apartamentos, un restaurante y una cafetería, sala de música, sala de lectura, etc., y los servicios generales correspondientes.
Sus tratamientos exterior e interior son correctos, de elegante sencillez, textura duradera y de fácil entretenimiento
A New Kind of Graded Lie Algebra and Parastatistical Supersymmetry
In this paper the usual graded Lie algebra is generalized to a new
form, which may be called graded Lie algebra. It is shown that there
exists close connections between the graded Lie algebra and
parastatistics, so the can be used to study and analyse various
symmetries and supersymmetries of the paraparticle systems
Observing the Suppression of Superconductivity in RbEuFe4As4 by Correlated Magnetic Fluctuations
In this Letter, we describe quantitative magnetic imaging of superconducting vortices in RbEuFe4As4 in order to investigate the unique interplay between the magnetic and superconducting sublattices. Our scanning Hall microscopy data reveal a pronounced suppression of the superfluid density near the magnetic ordering temperature in good qualitative agreement with a recently developed model describing the suppression of superconductivity by correlated magnetic fluctuations. These results indicate a pronounced exchange interaction between the superconducting and magnetic subsystems in RbEuFe4As4, with important implications for future investigations of physical phenomena arising from the interplay between them
Correlations of structural, magnetic, and dielectric properties of undoped and doped CaCu3Ti4O12
The present work reports synthesis, as well as a detailed and careful
characterization of structural, magnetic, and dielectric properties of
differently tempered undoped and doped CaCu3Ti4O12 (CCTO) ceramics. For this
purpose, neutron and x-ray powder diffraction, SQUID measurements, and
dielectric spectroscopy have been performed. Mn-, Fe-, and Ni-doped CCTO
ceramics were investigated in great detail to document the influence of
low-level doping with 3d metals on the antiferromagnetic structure and
dielectric properties. In the light of possible magnetoelectric coupling in
these doped ceramics, the dielectric measurements were also carried out in
external magnetic fields up to 7 T, showing a minor but significant dependence
of the dielectric constant on the applied magnetic field. Undoped CCTO is
well-known for its colossal dielectric constant in a broad frequency and
temperature range. With the present extended characterization of doped as well
as undoped CCTO, we want to address the question why doping with only 1% Mn or
0.5% Fe decreases the room-temperature dielectric constant of CCTO by a factor
of ~100 with a concomitant reduction of the conductivity, whereas 0.5% Ni
doping changes the dielectric properties only slightly. In addition,
diffraction experiments and magnetic investigations were undertaken to check
for possible correlations of the magnitude of the colossal dielectric constants
with structural details or with magnetic properties like the magnetic ordering,
the Curie-Weiss temperatures, or the paramagnetic moment. It is revealed, that
while the magnetic ordering temperature and the effective moment of all
investigated CCTO ceramics are rather similar, there is a dramatic influence of
doping and tempering time on the Curie-Weiss constant.Comment: 10 pages, 11 figure
Characterisation of the muon beams for the Muon Ionisation Cooling Experiment
A novel single-particle technique to measure emittance has been developed and used to characterise seventeen different muon beams for the Muon Ionisation Cooling Experiment (MICE). The muon beams, whose mean momenta vary from 171 to 281 MeV/c, have emittances of approximately 1.2–2.3 π mm-rad horizontally and 0.6–1.0 π mm-rad vertically, a horizontal dispersion of 90–190 mm and momentum spreads of about 25 MeV/c. There is reasonable agreement between the measured parameters of the beams and the results of simulations. The beams are found to meet the requirements of MICE
Assessment of Yellow Fever Epidemic Risk: An Original Multi-criteria Modeling Approach
This article describes the use of an original modeling approach to assess the risk of yellow fever (YF) epidemics. YF is a viral hemorrhagic fever responsible in past centuries for devastating outbreaks. Since the 1930s, a vaccine has been available that protects the individual for at least 10 years, if not for life. However, immunization of populations in African countries was gradually discontinued after the 1960s. With the decrease in immunity against YF in African populations the disease reemerged in the 1980s. In 2005, WHO, UNICEF, and the GAVI Alliance decided to support preventive vaccination of at-risk populations in West African endemic countries in order to tackle the reemergence of YF and reduce the risk of urban YF outbreaks. Financial resources were made available to scale up a global YF vaccine stockpile and to support countries with limited resources in the management of preventive vaccination campaigns. This article describes the process we used to determine the most at-risk populations using a mathematical model to prioritize targeted immunization campaigns. We believe that this approach could be useful for other diseases for which decision making process is difficult because of limited data availability, complex risk variables, and a need for rapid decisions and implementation
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