1,129 research outputs found
Recommended from our members
How well do high resolution models reproduce tropical convection?
Cascade is a multi-institution project studying the temporal and spatial organization of tropical convective systems. While cloud resolving numerical models can reproduce the observed diurnal cycle of such systems they are sensitive to the chosen resolution. As part of this effort, we are comparing results from the Met. Office Unified Model to data from the Global Earth Radiation Budget satellite instrument over the African Monsoon Interdisciplinary Analyses region of North Africa. We use a variety of mathematical techniques to study the outgoing radiation and the evolution of properties such as the cloud size distribution. The effectiveness of various model resolutions is tested with a view to determining the optimum balance between resolution and the need to reproduce the observations
Acid-sensing ion channels (ASICs) as pharmacological targets for neurodegenerative diseases
A significant drop of tissue pH or acidosis is a common feature of acute neurological conditions such as ischemic stroke, brain trauma, and epileptic seizures. Acid-sensing ion channels, or ASICs, are proton-gated cation channels widely expressed in peripheral sensory neurons and in the neurons of the central nervous system. Recent studies have demonstrated that activation of these channels by protons plays an important role in a variety of physiological and pathological processes such as nociception, mechanosensation, synaptic plasticity, and acidosis-mediated neuronal injury. This review provides an overview of the recent advance in electrophysiological, pharmacological characterization of ASICs, and their role in neurological diseases. Therapeutic potential of current available ASIC inhibitors is discussed
The application of Augmented Reality (AR) in the Architecture Engineering and Construction (AEC) industry
Augmented Reality (AR) as a concept has been in use for many years and prevalence of new mobile technologies, such as smartphones and handheld devices, have facilitated the concept of AR becoming fully realized. Various fields are exploiting the increasing feasibilities the concept of AR can offer; one of these being the Architecture, Engineering and Construction (AEC) industry. This paper introduces a research project that investigates benefits and limitations of AR for use in AEC industry. It starts with a brief background to the research before presenting a critical literature review, which forms the basis for the development and design of an AR experiment and a questionnaire for participants in the study. Results are provided with an in-depth discussion on their possible significance, before a conclusion is presented. The results suggest that although the participants believed that AR can offer a wide range of benefits to different tasks and at different stages of a project, it seems more beneficial to some specific tasks or at some specific stages than the others. Using the specific findings of this study future research in this field is proposed in different areas
Enhancing User Experience through VR:Case of an Urban Agriculture Participatory Design Experiment
Probabilistic instantaneous quantum computation
The principle of teleportation can be used to perform a quantum computation
even before its quantum input is defined. The basic idea is to perform the
quantum computation at some earlier time with qubits which are part of an
entangled state. At a later time a generalized Bell state measurement is
performed jointly on the then defined actual input qubits and the rest of the
entangled state. This projects the output state onto the correct one with a
certain exponentially small probability. The sufficient conditions are found
under which the scheme is of benefit.Comment: 4 pages, 1 figur
Arnowitt-Deser-Misner representation and Hamiltonian analysis of covariant renormalizable gravity
We study the recently proposed Covariant Renormalizable Gravity (CRG), which
aims to provide a generally covariant ultraviolet completion of general
relativity. We obtain a space-time decomposed form --- an Arnowitt-Deser-Misner
(ADM) representation --- of the CRG action. The action is found to contain time
derivatives of the gravitational fields up to fourth order. Some ways to reduce
the order of these time derivatives are considered. The resulting action is
analyzed using the Hamiltonian formalism, which was originally adapted for
constrained theories by Dirac. It is shown that the theory has a consistent set
of constraints. It is, however, found that the theory exhibits four propagating
physical degrees of freedom. This is one degree of freedom more than in
Ho\v{r}ava-Lifshitz (HL) gravity and two more propagating modes than in general
relativity. One extra physical degree of freedom has its origin in the higher
order nature of the CRG action. The other extra propagating mode is a
consequence of a projectability condition similarly as in HL gravity. Some
additional gauge symmetry may need to be introduced in order to get rid of the
extra gravitational degrees of freedom.Comment: 21 pages, LaTeX. A correction inserted to Hamiltonian formalism in
Sec.
Analysis of path integrals at low temperature : Box formula, occupation time and ergodic approximation
We study the low temperature behaviour of path integrals for a simple
one-dimensional model. Starting from the Feynman-Kac formula, we derive a new
functional representation of the density matrix at finite temperature, in terms
of the occupation times of Brownian motions constrained to stay within boxes
with finite sizes. From that representation, we infer a kind of ergodic
approximation, which only involves double ordinary integrals. As shown by its
applications to different confining potentials, the ergodic approximation turns
out to be quite efficient, especially in the low-temperature regime where other
usual approximations fail
The VLT-FLAMES survey of massive stars: observations in the Galactic clusters NGC3293, NGC4755 and NGC6611
We introduce a new survey of massive stars in the Galaxy and the Magellanic
Clouds using the Fibre Large Array Multi-Element Spectrograph (FLAMES)
instrument at the Very Large Telescope (VLT). Here we present observations of
269 Galactic stars with the FLAMES-Giraffe Spectrograph (R ~ 25,000), in fields
centered on the open clusters NGC 3293, NGC 4755 and NGC 6611. These data are
supplemented by a further 50 targets observed with the Fibre-Fed Extended Range
Optical Spectrograph (FEROS, R = 48,000). Following a description of our
scientific motivations and target selection criteria, the data reduction
methods are described; of critical importance the FLAMES reduction pipeline is
found to yield spectra that are in excellent agreement with less automated
methods. Spectral classifications and radial velocity measurements are
presented for each star, with particular attention paid to morphological
peculiarities and evidence of binarity. These observations represent a
significant increase in the known spectral content of NGC 3293 and NGC 4755,
and will serve as standards against which our subsequent FLAMES observations in
the Magellanic Clouds will be compared.Comment: 26 pages, 9 figures (reduced size). Accepted for publication in A&A.
A copy with full res. figures is available from
http://www.ing.iac.es/~cje/flames_mw.ps.gz. Minor changes following
correction of proof
- …