2,162 research outputs found
Single- and multi-photon excited fluorescence from serotonin complexed with B-cyclodextrin
The fluorescence of serotonin on binding with B-cyclodextrin has been studied using both steady-state and time-resolved methods. Steady state fluorescence intensity of serotonin at 340 nm showed ~ 30% increase in intensity on binding with Ka ~ 60 dm3 mol 1 and the fluorescence lifetimes showed a corresponding increase. In contrast, the characteristic green fluorescence (âhyperluminescenceâ) of serotonin observed upon multiphoton near-infrared excitation with sub-picosecond pulses was resolved into two lifetime components assigned to free and bound serotonin. The results are of interest in relation to selective imaging and detection of serotonin using the unusual hyperluminescence emission and in respect to recent determinations of serotonin by capillary electrophoresis in the presence of cyclodextrin. The results also suggest that hyperluminescence occurs from multiphoton excitation of a single isolated serotonin molecule
Regulation of 3Ⲡsplice site selection after step 1 of splicing by spliceosomal C* proteins
Alternative precursor messenger RNA splicing is instrumental in expanding the proteome of higher eukaryotes, and changes in 3Ⲡsplice site (3'ss) usage contribute to human disease. We demonstrate by small interfering RNAâmediated knockdowns, followed by RNA sequencing, that many proteins first recruited to human C* spliceosomes, which catalyze step 2 of splicing, regulate alternative splicing, including the selection of alternatively spliced NAGNAG 3â˛ss. Cryoâelectron microscopy and protein cross-linking reveal the molecular architecture of these proteins in C* spliceosomes, providing mechanistic and structural insights into how they influence 3'ss usage. They further elucidate the path of the 3Ⲡregion of the intron, allowing a structure-based model for how the C* spliceosome potentially scans for the proximal 3â˛ss. By combining biochemical and structural approaches with genome-wide functional analyses, our studies reveal widespread regulation of alternative 3â˛ss usage after step 1 of splicing and the likely mechanisms whereby C* proteins influence NAGNAG 3â˛ss choices
The QSL platform at LORIA
Colloque sans acte Ă diffusion restreinte. internationale.International audienceThe QSL project aims at the development of concepts, methods, techniques, and tools to increase the reliability and the quality of software intensive systems. Within this project, we are anticipating a platform of tools for validation and verification that ensures their availability, includes documentation and case studies, and eventually intends to foster the cooperation of different teams using different tools on common development projects
The Adaptive TreePM: An Adaptive Resolution Code for Cosmological N-body Simulations
Cosmological N-Body simulations are used for a variety of applications.
Indeed progress in the study of large scale structures and galaxy formation
would have been very limited without this tool. For nearly twenty years the
limitations imposed by computing power forced simulators to ignore some of the
basic requirements for modeling gravitational instability. One of the
limitations of most cosmological codes has been the use of a force softening
length that is much smaller than the typical inter-particle separation. This
leads to departures from collisionless evolution that is desired in these
simulations. We propose a particle based method with an adaptive resolution
where the force softening length is reduced in high density regions while
ensuring that it remains well above the local inter-particle separation. The
method, called the Adaptive TreePM, is based on the TreePM code. We present the
mathematical model and an implementation of this code, and demonstrate that the
results converge over a range of options for parameters introduced in
generalizing the code from the TreePM code. We explicitly demonstrate
collisionless evolution in collapse of an oblique plane wave. We compare the
code with the fixed resolution TreePM code and also an implementation that
mimics adaptive mesh refinement methods and comment on the agreement, and
disagreements in the results. We find that in most respects the ATreePM code
performs at least as well as the fixed resolution TreePM in highly over-dense
regions, from clustering and number density of haloes, to internal dynamics of
haloes. We also show that the adaptive code is faster than the corresponding
high resolution TreePM code.Comment: 18 pages, 11 figures. Accepted for publication in the MNRA
Parameter interdependence and uncertainty induced by lumping in a hydrologic model
Throughout the world, watershed modeling is undertaken using lumped parameter
hydrologic models that represent real-world processes in a manner that is at once abstract,
but nevertheless relies on algorithms that reflect real-world processes and parameters that
reflect real-world hydraulic properties. In most cases, values are assigned to the
parameters of such models through calibration against flows at watershed outlets. One
criterion by which the utility of the model and the success of the calibration process
are judged is that realistic values are assigned to parameters through this process. This
study employs regularization theory to examine the relationship between lumped
parameters and corresponding real-world hydraulic properties. It demonstrates that
any kind of parameter lumping or averaging can induce a substantial amount of âstructural
noiseâ which devices such as Box-Cox transformation of flows and auto-regressive
moving average (ARMA) modeling of residuals are unlikely to render homoscedastic
and uncorrelated. Furthermore, values estimated for lumped parameters are unlikely to
represent average values of the hydraulic properties after which they are named and
are often contaminated to a greater or lesser degree by the values of hydraulic properties
which they do not purport to represent at all. As a result, the question of how rigidly
they should be bounded during the parameter estimation process is still an open one
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
Using RGB-D sensors and evolutionary algorithms for the optimization of workstation layouts
[EN] RGB-D sensors can collect postural data in an automatized way. However, the application of these devices in real work environments requires overcoming problems such as lack of accuracy or body parts' occlusion. This work presents the use of RGB-D sensors and genetic algorithms for the optimization of workstation layouts. RGB-D sensors are used to capture workers' movements when they reach objects on workbenches. Collected data are then used to optimize workstation layout by means of genetic algorithms considering multiple ergonomic criteria. Results show that typical drawbacks of using RGB-D sensors for body tracking are not a problem for this application, and that the combination with intelligent algorithms can automatize the layout design process. The procedure described can be used to automatically suggest new layouts when workers or processes of production change, to adapt layouts to specific workers based on their ways to do the tasks, or to obtain layouts simultaneously optimized for several production processes.This work was supported by the Programa estatal de investigacion, desarrollo e innovacion orientada a los retos de la sociedad of the Government of Spain under Grant TIN2013-42504-R.Diego-Mas, JA.; Poveda Bautista, R.; Garzon-Leal, D. (2017). Using RGB-D sensors and evolutionary algorithms for the optimization of workstation layouts. Applied Ergonomics. 65:530-540. doi:10.1016/j.apergo.2017.01.012S5305406
Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at â s = 8 TeV with the ATLAS detector
Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fbâ1 of â s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
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