18 research outputs found
Data Fusion of Objects Using Techniques Such as Laser Scanning, Structured Light and Photogrammetry for Cultural Heritage Applications
In this paper we present a semi-automatic 2D-3D local registration pipeline
capable of coloring 3D models obtained from 3D scanners by using uncalibrated
images. The proposed pipeline exploits the Structure from Motion (SfM)
technique in order to reconstruct a sparse representation of the 3D object and
obtain the camera parameters from image feature matches. We then coarsely
register the reconstructed 3D model to the scanned one through the Scale
Iterative Closest Point (SICP) algorithm. SICP provides the global scale,
rotation and translation parameters, using minimal manual user intervention. In
the final processing stage, a local registration refinement algorithm optimizes
the color projection of the aligned photos on the 3D object removing the
blurring/ghosting artefacts introduced due to small inaccuracies during the
registration. The proposed pipeline is capable of handling real world cases
with a range of characteristics from objects with low level geometric features
to complex ones
Attenuation of the Sensing Capabilities of PhoQ in Transition to Obligate Insect–Bacterial Association
Sodalis glossinidius, a maternally inherited endosymbiont of the tsetse fly, maintains genes encoding homologues of the PhoP-PhoQ two-component regulatory system. This two-component system has been extensively studied in facultative bacterial pathogens and is known to serve as an environmental magnesium sensor and a regulator of key virulence determinants. In the current study, we show that the inactivation of the response regulator, phoP, renders S. glossinidius sensitive to insect derived cationic antimicrobial peptides (AMPs). The resulting mutant strain displays reduced expression of genes involved in the structural modification of lipid A that facilitates resistance to AMPs. In addition, the inactivation of phoP alters the expression of type-III secretion system (TTSS) genes encoded within three distinct chromosomal regions, indicating that PhoP-PhoQ also serves as a master regulator of TTSS gene expression. In the absence of phoP, S. glossinidius is unable to superinfect either its natural tsetse fly host or a closely related hippoboscid louse fly. Furthermore, we show that the S. glossinidius PhoQ sensor kinase has undergone functional adaptations that result in a substantially diminished ability to sense ancestral signals. The loss of PhoQ's sensory capability is predicted to represent a novel adaptation to the static symbiotic lifestyle, allowing S. glossinidius to constitutively express genes that facilitate resistance to host derived AMPs
Generating keV ion distributions for nuclear reactions at near solid-density using intense short-pulse lasers
Neutropenia induced by high-dose intravenous benzylpenicillin in treating neurosyphilis: Does it really matter?
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A search for bremsstrahlung solar axions using the Majorana low-background BEGe detector at Kimballton (MALBEK)
A low-background, high-purity germanium detector has been used to search for
evidence of low-energy, bremsstrahlung-generated solar axions. An upper bound
of is placed on the direct coupling of DFSZ
model axions to electrons. The prospects for the sensitivity of the Majorana
Demonstrator array of point-contact germanium detectors to solar axions are
discussed in the context of the model-independent annual modulation due to the
seasonal variation of the earth-sun distance
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The Majorana Demonstrator radioassay program
The Majorana collaboration is constructing the Majorana Demonstrator at the Sanford Underground Research Facility at the Homestake gold mine, in Lead, SD. The apparatus will use Ge detectors, enriched in isotope 76Ge, to demonstrate the feasibility of a large-scale Ge detector experiment to search for neutrinoless double beta decay. The long half-life of this postulated process requires that the apparatus be extremely low in radioactive isotopes whose decays may produce backgrounds to the search. The radioassay program conducted by the collaboration to ensure that the materials comprising the apparatus are sufficiently pure is described. The resulting measurements from gamma-ray counting, neutron activation and mass spectroscopy of the radioactive-isotope contamination for the materials studied for use in the detector are reported. We interpret these numbers in the context of the expected background for the experiment
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The {\sc Majorana Demonstrator} Neutrinoless Double-Beta Decay Experiment
The {\sc Majorana Demonstrator will search for the neutrinoless double-beta
decay of the isotope Ge-76 with a mixed array of enriched and natural germanium
detectors. The observation of this rare decay would indicate the neutrino is
its own antiparticle, demonstrate that lepton number is not conserved, and
provide information on the absolute mass scale of the neutrino. The {\sc
Demonstrator} is being assembled at the 4850-foot level of the Sanford
Underground Research Facility in Lead, South Dakota. The array will be situated
in a low-background environment and surrounded by passive and active shielding.
Here we describe the science goals of the {\sc Demonstrator} and the details of
its design
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The Majorana Demonstrator Neutrinoless Double-Beta Decay Experiment
The {\sc Majorana Demonstrator will search for the neutrinoless double-beta decay of the isotope Ge-76 with a mixed array of enriched and natural germanium detectors. The observation of this rare decay would indicate the neutrino is its own antiparticle, demonstrate that lepton number is not conserved, and provide information on the absolute mass scale of the neutrino. The {\sc Demonstrator} is being assembled at the 4850-foot level of the Sanford Underground Research Facility in Lead, South Dakota. The array will be situated in a low-background environment and surrounded by passive and active shielding. Here we describe the science goals of the {\sc Demonstrator} and the details of its design.The MAJORANA DEMONSTRATOR will search for the neutrinoless double-beta decay of the isotope Ge with a mixed array of enriched and natural germanium detectors. The observation of this rare decay would indicate that the neutrino is its own antiparticle, demonstrate that lepton number is not conserved, and provide information on the absolute mass scale of the neutrino. The DEMONSTRATOR is being assembled at the 4850-foot level of the Sanford Underground Research Facility in Lead, South Dakota. The array will be situated in a low-background environment and surrounded by passive and active shielding. Here we describe the science goals of the DEMONSTRATOR and the details of its design
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Background Model for the Majorana Demonstrator
The Majorana Collaboration is constructing a system containing 40 kg of HPGe
detectors to demonstrate the feasibility and potential of a future tonne-scale
experiment capable of probing the neutrino mass scale in the inverted-hierarchy
region. To realize this, a major goal of the Majorana Demonstrator is to
demonstrate a path forward to achieving a background rate at or below 1
cnt/(ROI-t-y) in the 4 keV region of interest around the Q-value at 2039 keV.
This goal is pursued through a combination of a significant reduction of
radioactive impurities in construction materials with analytical methods for
background rejection, for example using powerful pulse shape analysis
techniques profiting from the p-type point contact HPGe detectors technology.
The effectiveness of these methods is assessed using simulations of the
different background components whose purity levels are constrained from
radioassay measurements