1,770 research outputs found
On the stability of periodic orbits in delay equations with large delay
We prove a necessary and sufficient criterion for the exponential stability
of periodic solutions of delay differential equations with large delay. We show
that for sufficiently large delay the Floquet spectrum near criticality is
characterized by a set of curves, which we call asymptotic continuous spectrum,
that is independent on the delay.Comment: postprint versio
Исследование влияния механоактивации порошковой композиции на структуру спеченных изделий
Laser-based imaging of fuel vapor distribution, ignition, and soot formation in diesel sprays was carried out in a high-pressure, high-temperature spray chamber under conditions that correspond to temperature and pressure in a diesel engine. Rayleigh scattering and laser-induced incandescence are used to image fuel density and soot volume fraction. The experimental results provide data for comparison with numerical simulations. An interactive cross-sectionally averaged spray model based on Eulerian transport equations was used for the simulation of the spray, and the turbulence-chemistry interaction was modeled with the representative interactive flamelet (RIF) concept. The flamelet calculation is coupled to the Kiva3V computational fluid dynamics (CFD) code using the scalar dissipation rate and pressure as an input to the RIF-code. The flamelet code computes the instationary flamelet profiles for every time step. These profiles were integrated over mixture fraction space using a prescribed β-PDF to obtain mean values, which are passed back to the CFD-code. Thereby, the temperature and the relevant species in each CFD-cell were obtained. The fuel distribution, the average ignition delay as well as the location of ignition are well predicted by the simulation. Furthermore, simulations show that the experimentally observed injection-to-injection variations in ignition delay are due to temperature inhomogeneities. Experimental and simulated spatial soot and fuel vapor density distributions are compared during and after second stage ignition. 2004 The Combustion Institute. Published by Elsevier Inc. All rights reserved
I-mode studies at ASDEX Upgrade: L-I and I-H transitions, pedestal and confinement properties
The I-mode is a plasma regime obtained when the usual L-H power threshold is high, e.g. 
with unfavourable ion 
B
∇
 direction. It is characterised by the development of a temperature 
pedestal while the density remains roughly as in the L-mode. This leads to a confinement 
improvement above the L-mode level which can sometimes reach H-mode values. This 
regime, already obtained in the ASDEX Upgrade tokamak about two decades ago, has 
been studied again since 2009 taking advantage of the development of new diagnostics 
and heating possibilities. The I-mode in ASDEX Upgrade has been achieved with different 
heating methods such as NBI, ECRH and ICRF. The I-mode properties, power threshold, 
pedestal characteristics and confinement, are independent of the heating method. The power 
required at the L-I transition exhibits an offset linear density dependence but, in contrast 
to the L-H threshold, depends weakly on the magnetic field. The L-I transition seems to be 
mainly determined by the edge pressure gradient and the comparison between ECRH and 
NBI induced L-I transitions suggests that the ion channel plays a key role. The I-mode often 
evolves gradually over a few confinement times until the transition to H-mode which offers 
a very interesting situation to study the transport reduction and its link with the pedestal 
formation. Exploratory discharges in which 
n
=
  2 magnetic perturbations have been applied 
indicate that these can lead to an increase of the I-mode power threshold by flattening the edge 
pressure at fixed heating input power: more heating power is necessary to restore the required 
edge pressure gradient. Finally, the confinement properties of the I-mode are discussed in 
detail.European Commission (EUROfusion 633053
Microdissection of human chromosomes by a laser microbeam
A laser microbeam apparatus, based on an excimer laser pumped dye laser is used to microdissect human chromosomes and to isolate a single chromosome slice
A homozygous mutation in the TUB gene associated with retinal dystrophy and obesity.
Inherited retinal dystrophies are a major cause of childhood blindness. Here, we describe the identification of a homozygous frameshift mutation (c.1194_1195delAG, p.Arg398Serfs*9) in TUB in a child from a consanguineous UK Caucasian family investigated using autozygosity mapping and whole-exome sequencing. The proband presented with obesity, night blindness, decreased visual acuity, and electrophysiological features of a rod cone dystrophy. The mutation was also found in two of the proband's siblings with retinal dystrophy and resulted in mislocalization of the truncated protein. In contrast to known forms of retinal dystrophy, including those caused by mutations in the tubby-like protein TULP-1, loss of function of TUB in the proband and two affected family members was associated with early-onset obesity, consistent with an additional role for TUB in energy homeostasis.Contract grant sponsors: Wellcome Trust (077016/Z/05/Z, 098497/Z/12/Z,
096106/Z/11/Z); National Institute for Health Research (Moorfields Biomedical Research
Centre and Cambridge Biomedical Research Centre); Fight for Sight; Foundation
Fighting Blindness (USA); the Rosetrees Trust; European Community (FP7/2009/241955
“SYSCILIA”); The FAUN Foundation (Germany).This is the final published version. It first appeared at http://onlinelibrary.wiley.com/doi/10.1002/humu.22482/abstract
Fast-ion redistribution and loss due to edge perturbations in the ASDEX Upgrade, DIII-D and KSTAR tokamaks
The impact of edge localized modes (ELMs) and externally applied resonant and non-resonant magnetic perturbations
(MPs) on fast-ion confinement/transport have been investigated in the ASDEX Upgrade (AUG), DIII-D and KSTAR
tokamaks. Two phases with respect to the ELM cycle can be clearly distinguished in ELM-induced fast-ion losses.
Inter-ELM losses are characterized by a coherent modulation of the plasma density around the separatrix while
intra-ELM losses appear as well-defined bursts.  In high collisionality plasmas with mitigated ELMs, externally
applied MPs have little effect on kinetic profiles, including fast-ions, while a strong impact on kinetic profiles is
observed in low-collisionality, low
q
95
plasmas with resonant and non-resonant MPs. In low-collisionality H-mode
plasmas, the large fast-ion filaments observed during ELMs are replaced by a loss of fast-ions with a broad-band
frequency and an amplitude of up to an order of magnitude higher than the neutral beam injection prompt loss signal
without MPs.  A clear synergy in the overall fast-ion transport is observed between MPs and neoclassical tearing
modes. Measured fast-ion losses are typically on banana orbits that explore the entire pedestal/scrape-off layer. The
fast-ion response to externally applied MPs presented here may be of general interest for the community to better
understand the MP field penetration and overall plasma response.Ministerio de Economía y Empresa ((RYC-2011-09152 y ENE2012-31087)Marie Curie (Grant PCIG11-GA-2012-321455)US Department of Energy (DE-FC02-04ER54698, SC-G903402, DE-FG02-04ER54761, DE-AC02-09CH11466 and DE-FG02- 08ER54984)NRF Korea contract 2009-0082012MEST under the KSTAR projec
A striking correspondence between the dynamics generated by the vector fields and by the scalar parabolic equations
The purpose of this paper is to enhance a correspondence between the dynamics
of the differential equations  on  and those
of the parabolic equations  on a bounded
domain . We give details on the similarities of these dynamics in the
cases ,  and  and in the corresponding cases ,
 and dim() respectively. In addition to
the beauty of such a correspondence, this could serve as a guideline for future
research on the dynamics of parabolic equations
Macropinocytotic uptake and infection of human epithelial cells with species B2 adenovirus type 35
The human adenovirus serotype 35 (HAdV-35, short Ad35) causes kidney and urinary tract infections, and infects respiratory organs of immunocompromised individuals. Unlike other adenoviruses, Ad35 has a low seroprevalence which makes Ad35-based vectors promising candidates for gene therapy. Ad35 utilizes CD46 and integrins as receptors for infection of epithelial and hematopoietic cells. Here, we show that infectious entry of Ad35 into HeLa, human kidney HK-2 cells and normal human lung fibroblasts strongly depended on CD46 and integrins but not heparan sulfate, and variably required the large GTPase dynamin. Ad35 infections were independent of expression of the carboxy-terminal domain of AP180 which effectively blocks clathrin-mediated uptake. Ad35 infections were inhibited by small chemicals against the serine/threonine kinase Pak1 (p21-activated kinase), protein kinase C (PKC), sodium-proton exchangers, actin and acidic organelles. Remarkably, the F-actin inhibitor jasplakinolide, the Pak1 inhibitor IPA-3 or the sodium-proton exchange inhibitor EIPA blocked the endocytic uptake of Ad35. Dominant-negative proteins or small interfering RNAs against factors driving macropinocytosis, including the small GTPase Rac1, Pak1 or the Pak1 effector C-terminal binding protein 1 (CtBP1) potently inhibited Ad35 infection. Confocal laser scanning microscopy, electron microscopy and live cell imaging showed that Ad35 colocalized with fluid phase markers in large endocytic structures that were positive for CD46, alpha v integrins and also CtBP1. Our results extend earlier observations with HAdV-3 (Ad3), and establish macropinocytosis as an infectious pathway for species B human adenoviruses in epithelial and hematopoietic cells
Biodiversity indicators in organic and conventional farming systems: main results from the European project BIOBIO
In the framework of the European project BIOBIO, we compared between countries habitat and cumulated species richnesses of plants, wild bees, spiders and earthworms, measured in 169 conventional and organic farms belonging to 10 case studies in 10 European countries. For the French case study (Gascony Valleys and Hills), correlations between direct (habitat and taxonomic richnesses) and indirect (agricultural practices) indicators of biodiversity within 8 conventional and 8 organic farms, were calculated. Results showed that the main driver of biodiversity at the farm level was the number of cultivated and above all semi-natural habitats, inthe French case study region as well as inthe other regions. This factor partially explained the highest biodiversity level of the French case study region. However, farming practices, specific or not to the organic and conventional systems, most often drove biodiversity parameters at the habitat level. In fine, the project proposed the BIOBIO method for monitoring biodiversity in farms
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