2,801 research outputs found
Fondos EIE: reforzando la solidaridad y las regiones europeas
El ISSN corresponde a la versión electrónica del documentoLa eurodiputada Kerstin Westphal, miembro de la Comisión de Desarrollo Regional del Parlamento Europeo, comparte sus puntos de vista y expectativas respecto a la ejecución de los Fondos EIE y su impacto hasta la fecha
Molecular cloning and expression analysis of MPPa-2, a novel mouse transcript detected in a differential screen of pituitary libraries
We identified a novel isoform transcript, MPP alpha-2, of the mouse Mg(2+)-dependent protein phosphatase (MPP) alpha gene. The amino acid sequence encoded by MPP alpha-2 differs from the previously known MPP alpha-1 sequence only at the carboxyl terminal region. Northern and in situ hybridization analysis revealed differential expression patterns of these two transcripts in the embryo and in the adult organism, suggesting an elaborate regulation of the MPP alpha gene
New Candidate Interstellar Particle in Stardust IS Aerogel Collector: Analysis by STXM and Ptychography
The Stardust Interstellar Preliminary Examination (ISPE) reported in 2014 the discovery of 7 probable contemporary interstellar (IS) particles captured in Stardust IS Collector aerogel and foils. The ISPE reports represented work done over 6 years by more than 60 scientists and >30,000 volunteers, which emphasizes the challenge identifying and analyzing Stardust IS samples was far beyond the primary Stardust cometary collection. We present a new potentially interstellar particle resulting from a continuation of analyses of the IS aerogel collection
The Braincase and Neurosensory Anatomy of an Early Jurassic Marine Crocodylomorph: Implications for Crocodylian Sinus Evolution and Sensory Transitions
This is the pre-peer reviewed version of the following article: Brusatte, S. L., Muir, A. , Young, M. T., Walsh, S. , Steel, L. and Witmer, L. M. (2016), The Braincase and Neurosensory Anatomy of an Early Jurassic Marine Crocodylomorph: Implications for Crocodylian Sinus Evolution and Sensory Transitions. Anat. Rec., 299: 1511-1530., which has been published in final form at doi:10.1002/ar.23462. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving." You are advised to consult the published version if you wish to cite from it
Using geographical coordinates to attain efficient route signaling in ad hoc networks
Flooding of route requests or link states is a necessity in many routing protocols for mobile ad hoc networks (MANET), and several mechanisms have been devised to make flooding more efficient; however, all flooding approaches to date are such that the number of neighbors each node must use to relay a flooded packet grows as the node density increases. A new method, called ORCA (On-demand Routing with Coordinates Awareness) is introduced for the dissemination of route requests in MANETs. The selection of relaying nodes at each node in ORCA is done by computing the shortest Euclidean Distance from all neighbors of the node to four polar points located in the transmission range of the node. We prove that ORCA guarantees the coverage of all nodes in a connected MANET, and that the number of relays for each node is at most six. ORCA is compared with representative routing protocols, namely AODV, OLSR, LAR, and THP. The simulation results in networks of 200 and 250 nodes show that ORCA incurs the smallest routing load while attaining average delays and packet delivery ratios that are comparable to or better than those obtained with the other four routing protocols
Impact of data quality and surface-to-column representativeness on the PM<sub>2.5</sub> / satellite AOD relationship for the contiguous United States
Satellite-derived aerosol optical depth (AOD) observations have been used to
estimate particulate matter smaller than 2.5 μm (PM<sub>2.5</sub>). However,
such a relationship could be affected by the representativeness of
satellite-derived AOD to surface aerosol particle mass concentration and
satellite AOD data quality. Using purely measurement-based methods, we have
explored the impacts of data quality and representativeness on the AOD-inferred
PM<sub>2.5</sub> / AOD relationship for the contiguous United States
(CONUS). This is done through temporally and spatially collocated data sets of
PM<sub>2.5</sub> and AOD retrievals from Aqua/Terra Moderate Resolution Imaging
Spectroradiometer (MODIS), Multi-angle Imaging Spectroradiometer (MISR), and
Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP). These analyses
show that improving data quality of satellite AOD, such as done with data
assimilation-grade retrievals, increases their correlation with PM<sub>2.5</sub>.
However, overall correlation is relatively low across the CONUS. Also,
integrated extinction observed within 500 m above ground level (a.g.l.),
as measured by CALIOP, is not well representative of the total column AOD.
Surface aerosol in the eastern CONUS is better correlated with total column AOD than in the western
CONUS. The best correlation values are found for estimated dry mass CALIOP
extinction at 200–300 m a.g.l. and PM<sub>2.5</sub>, but additional work is
needed to address the ability of using actively sensed AOD as a proxy for
PM<sub>2.5</sub> concentrations
The CRESST Dark Matter Search
We present first competitive results on WIMP dark matter using the
phonon-light-detection technique. A particularly strong limit for WIMPs with
coherent scattering results from selecting a region of the phonon-light plane
corresponding to tungsten recoils. The observed count rate in the neutron band
is compatible with the rate expected from neutron background. CRESST is
presently being upgraded with a 66 channel SQUID readout system, a neutron
shield and a muon veto system. This results in a significant improvement in
sensitivity.Comment: 6 pages, 3 figures, to be published in the proceedings of the 5th
International Workshop on the Identification and Detection of Dark Matter IDM
2004, Edinburgh, Sept. 2004, World Scientifi
Disorder and relaxation mode in the lattice dynamics of PbMgNbO relaxor ferroelectric
The low-energy part of vibration spectrum in PbMgNbO
relaxor ferroelectric was studied by inelastic neutron scattering. We observed
the coexistence of a resolution-limited central peak with strong quasielastic
scattering. The line-width of the quasielastic component follows a
dependence. We find that is temperature-dependent.
The relaxation time follows the Arrhenius law well. The presence of a
relaxation mode associated with quasi-elastic scattering in PMN indicates that
order-disorder behaviour plays an important r\^ole in the dynamics of diffuse
phase transitions
Navigation system for robot-assisted intra-articular lower-limb fracture surgery
Purpose
In the surgical treatment for lower-leg intra-articular fractures, the fragments have to be positioned and aligned to reconstruct the fractured bone as precisely as possible, to allow the joint to function correctly again. Standard procedures use 2D radiographs to estimate the desired reduction position of bone fragments. However, optimal correction in a 3D space requires 3D imaging. This paper introduces a new navigation system that uses pre-operative planning based on 3D CT data and intra-operative 3D guidance to virtually reduce lower-limb intra-articular fractures. Physical reduction in the fractures is then performed by our robotic system based on the virtual reduction.
Methods
3D models of bone fragments are segmented from CT scan. Fragments are pre-operatively visualized on the screen and virtually manipulated by the surgeon through a dedicated GUI to achieve the virtual reduction in the fracture. Intra-operatively, the actual position of the bone fragments is provided by an optical tracker enabling real-time 3D guidance. The motion commands for the robot connected to the bone fragment are generated, and the fracture physically reduced based on the surgeon’s virtual reduction. To test the system, four femur models were fractured to obtain four different distal femur fracture types. Each one of them was subsequently reduced 20 times by a surgeon using our system.
Results
The navigation system allowed an orthopaedic surgeon to virtually reduce the fracture with a maximum residual positioning error of 0.95±0.3mm (translational) and 1.4∘±0.5∘ (rotational). Correspondent physical reductions resulted in an accuracy of 1.03 ± 0.2 mm and 1.56∘±0.1∘, when the robot reduced the fracture.
Conclusions
Experimental outcome demonstrates the accuracy and effectiveness of the proposed navigation system, presenting a fracture reduction accuracy of about 1 mm and 1.5∘, and meeting the clinical requirements for distal femur fracture reduction procedures
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