24,974 research outputs found
A graphical, scalable and intuitive method for the placement and the connection of biological cells
We introduce a graphical method originating from the computer graphics domain
that is used for the arbitrary and intuitive placement of cells over a
two-dimensional manifold. Using a bitmap image as input, where the color
indicates the identity of the different structures and the alpha channel
indicates the local cell density, this method guarantees a discrete
distribution of cell position respecting the local density function. This
method scales to any number of cells, allows to specify several different
structures at once with arbitrary shapes and provides a scalable and versatile
alternative to the more classical assumption of a uniform non-spatial
distribution. Furthermore, several connection schemes can be derived from the
paired distances between cells using either an automatic mapping or a
user-defined local reference frame, providing new computational properties for
the underlying model. The method is illustrated on a discrete homogeneous
neural field, on the distribution of cones and rods in the retina and on a
coronal view of the basal ganglia.Comment: Corresponding code at https://github.com/rougier/spatial-computatio
Microcircuit testing and fabrication, using scanning electron microscopes
Scanning electron microscopes are used to determine both user-induced damages and manufacturing defects subtle enough to be missed by conventional light microscopy. Method offers greater depth of field and increased working distances
Dicarba-closo-dodecarborane-containing half-sandwich complexes of ruthenium, osmium, rhodium and iridium : biological relevance and synthetic strategies
This review describes how the incorporation of dicarba-closo-dodecarboranes into half-sandwich complexes of ruthenium, osmium, rhodium and iridium might lead to the development of a new class of compounds with applications in medicine. Such a combination not only has unexplored potential in traditional areas such as Boron Neutron Capture Therapy agents, but also as pharmacophores for the targeting of biologically important proteins and the development of targeted drugs. The synthetic pathways used for the syntheses of dicarba-closo-dodecarboranes-containing half-sandwich complexes of ruthenium, osmium, rhodium and iridium are also reviewed. Complexes with a wide variety of geometries and characteristics can be prepared. Examples of addition reactions on the metal centre, BâH activation, transmetalation reactions and/or direct formation of metalâmetal bonds are discussed (103 references)
Spatial filtering in multichannel magnetoencephalography
Partial differential equations in boundary-value problems have been studied in order to estimate the influence of several geometrical and physical parameters involved in the outward transmission of the brain's magnetic field. Explicit Green kernels are used to obtain integral forms of generalized solutions which can be deduced from each other, as expressed over concentric spherical surfaces. That leads to numerical applications dealing with the radial component of the magnetic field. From this study, a new spatial filtering is proposed as a possible improvement in two-dimensional magnetoencephalographic mapping using large multisensors
Gamow-Teller properties of the double beta-decay partners 116Cd(Sn) and 150Nd(Sm)
The two Gamow-Teller (GT) branches connecting the double-beta decay partners
(116Cd, 116Sn) and (150Nd, 150Sm) with the intermediate nuclei 116In and 150Pm
are studied within a microscopic approach based on a deformed proton-neutron
quasiparticle random-phase approximation built on a Skyrme selfconsistent mean
field with pairing correlations and spin-isospin residual forces. The results
are compared with the experimental GT strength distributions extracted from
charge-exchange reactions. Combining the two branches, the nuclear matrix
elements for the two-neutrino double-beta decay are evaluated and compared to
experimental values derived from the measured half-lives.Comment: 10 pages, 16 figure
Description of GADEL
This article describes the first implementation of the GADEL system : a
Genetic Algorithm for Default Logic. The goal of GADEL is to compute extensions
in Reiter's default logic. It accepts every kind of finite propositional
default theories and is based on evolutionary principles of Genetic Algorithms.
Its first experimental results on certain instances of the problem show that
this new approach of the problem can be successful.Comment: System Descriptions and Demonstrations at Nonmonotonic Reasoning
Workshop, 2000 6 pages, 2 figures, 5 table
Regulating Mobile Mental Health Apps
Mobile medical apps (MMAs) are a fastâgrowing category of software typically installed on personal smartphones and wearable devices. A subset of MMAs are aimed at helping consumers identify mental states and/or mental illnesses. Although this is a fledgling domain, there are already enough extant mental health MMAs both to suggest a typology and to detail some of the regulatory issues they pose. As to the former, the current generation of apps includes those that facilitate selfâassessment or selfâhelp, connect patients with online support groups, connect patients with therapists, or predict mental health issues. Regulatory concerns with these apps include their quality, safety, and data protection. Unfortunately, the regulatory frameworks that apply have failed to provide coherent riskâassessment models. As a result, prudent providers will need to progress with caution when it comes to recommending apps to patients or relying on appâgenerated data to guide treatment
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