1,292 research outputs found
Combining visibility analysis and deep learning for refinement of semantic 3D building models by conflict classification
Semantic 3D building models are widely available and used in numerous applications. Such 3D building models display rich semantics but no façade openings, chiefly owing to their aerial acquisition techniques. Hence, refining models’ façades using dense, street-level, terrestrial point clouds seems a promising strategy. In this paper, we propose a method of combining visibility analysis and neural networks for enriching 3D models with window and door features. In the method, occupancy voxels are fused with classified point clouds, which provides semantics to voxels. Voxels are also used to identify conflicts between laser observations and 3D models. The semantic voxels and conflicts are combined in a Bayesian network to classify and delineate façade openings, which are reconstructed using a 3D model library. Unaffected building semantics is preserved while the updated one is added, thereby upgrading the building model to LoD3. Moreover, Bayesian network results are back-projected onto point clouds to improve points’ classification accuracy. We tested our method on a municipal CityGML LoD2 repository and the open point cloud datasets: TUM-MLS-2016 and TUM-FAÇADE. Validation results revealed that the method improves the accuracy of point cloud semantic segmentation and upgrades buildings with façade elements. The method can be applied to enhance the accuracy of urban simulations and facilitate the development of semantic segmentation algorithms
PHENIX first measurement of the J/psi elliptic flow parameter v2 in Au+Au collisions at sqrt(sNN) = 200 GeV
Recent results indicate that the J/psi suppression pattern differs with
rapidity showing a larger suppression at forward rapidity. J/psi suppression
mechanisms based on energy density (such as color screening, interaction with
co-movers, etc.) predict the opposite trend. On the other hand, it is expected
that more c\bar{c} pairs should be available to form quarkonia at mid-rapidity
via recombination. Some models provide a way to differentiate J/psi production
from initially produced c\bar{c} pairs and final state recombination of
uncorrelated pairs, via the rapidity and transverse momentum dependence of the
elliptic flow (v2).
During 2007 data taking at RHIC, a large sample of Au+Au collisions at
sqrt(sNN)=200 GeV was collected. The statistics has been increased compared to
previous 2004 data set, thus allowing a more precise measurement of the J/psi
production at both mid and forward rapidity. Furthermore, the PHENIX experiment
benefited from the addition of a new detector, which improves the reaction
plane resolution and allows us to measure the J/psi v2. Comparing this
measurement to the positive D-mesons v2 (through non-photonic electron decays)
will help constraining the J/psi production mechanisms and getting a more
precise picture of the proportion of J/psi coming from direct production or
charm quark coalescence.
Details on how the J/psi v2 is measured at both rapidities are presented. The
J/psi v2 as a function of transverse momentum are compared to existing models.Comment: 4 pages, 3 figures, Quark Matter 2008 proceeding
Dynamics of lane formation in driven binary complex plasmas
The dynamical onset of lane formation is studied in experiments with binary
complex plasmas under microgravity conditions. Small microparticles are driven
and penetrate into a cloud of big particles, revealing a strong tendency
towards lane formation. The observed time-resolved lane formation process is in
good agreement with computer simulations of a binary Yukawa model with Langevin
dynamics. The laning is quantified in terms of the anisotropic scaling index,
leading to a universal order parameter for driven systems.Comment: 4 pages, 3 figures, movies available at
http://www.mpe.mpg.de/pke/lane-formation
γδ T cells affect IL-4 production and B-cell tolerance
γδ T cells can influence specific antibody responses. Here, we report that mice deficient in individual γδ T-cell subsets have altered levels of serum antibodies, including all major subclasses, sometimes regardless of the presence of αβ T cells. One strain with a partial γδ deficiency that increases IgE antibodies also displayed increases in IL-4–producing T cells (both residual γδ T cells and αβ T cells) and in systemic IL-4 levels. Its B cells expressed IL-4–regulated inhibitory receptors (CD5, CD22, and CD32) at diminished levels, whereas IL-4–inducible IL-4 receptor α and MHCII were increased. They also showed signs of activation and spontaneously formed germinal centers. These mice displayed IgE-dependent features found in hyper-IgE syndrome and developed antichromatin, antinuclear, and anticytoplasmic autoantibodies. In contrast, mice deficient in all γδ T cells had nearly unchanged Ig levels and did not develop autoantibodies. Removing IL-4 abrogated the increases in IgE, antichromatin antibodies, and autoantibodies in the partially γδ-deficient mice. Our data suggest that γδ T cells, controlled by their own cross-talk, affect IL-4 production, B-cell activation, and B-cell tolerance
Correlation of protection against varicella in a randomized Phase III varicella-containing vaccine efficacy trial in healthy infants
Background: Varicella vaccination confers high and long-lasting protection against chickenpox and induces robust immune responses, but an absolute correlate of protection (CoP) against varicella has not been established. This study models the relationship between varicella humoral response and protection against varicella. Methods: This was a post-hoc analysis of data from a Phase IIIb, multicenter, randomized trial (NCT00226499) conducted in ten varicella-endemic European countries. Healthy children aged 12–22 months were randomized 3:3:1 to receive one dose of measles-mumps-rubella and one dose of varicella vaccine (one-dose group) or two doses of measles-mumps-rubella-varicella vaccine (two-dose group) or two doses of measles-mumps-rubella vaccine (control group) six weeks apart. The study remained observer-blind until completion, except in countries with obligatory additional immunizations. The objective was to correlate varicella-specific antibody concentrations with protection against varicella and probability of varicella breakthrough, using Cox proportional hazards and Dunning and accelerated failure time statistical models. The analysis was guided by the Prentice framework to explore a CoP against varicella. Results: The trial included 5803 participants, 5289 in the efficacy (2266: one-dose group, 2279: two-dose group and 744: control group) and 5235 (2248, 2245 and 742 in the same groups) in the immunogenicity cohort. The trial ended in 2016 with a median follow-up time of 9.8 years. Six weeks after vaccination with one- or two-dose varicella-containing vaccine, more than 93.0% of vaccinees were seropositive for varicella-specific antibodies. Estimated vaccine efficacy correlated positively with antibody concentrations. The fourth Prentice CoP criterion was not met, due to predicted positive vaccine efficacy in seronegative participants. Further modelling showed decreased probability of moderate to severe varicella breakthrough with increasing varicella-specific antibody concentrations (ten-year probability <0.1 for antibody concentrations ≥2-fold above the seropositivity cut-off). Conclusions: Varicella-specific antibody concentrations are a good predictor of protection, given their inverse correlation with varicella occurrence. Clinical trial: NCT00226499
Cognitive Function in Type 1 Diabetic Adults With Early Exposure to Severe Hypoglycemia: A 16-year follow-up study
Topoisomer Differentiation of Molecular Knots by FTICR MS: Lessons from Class II Lasso Peptides
Lasso peptides constitute a class of bioactive peptides sharing a knotted
structure where the C-terminal tail of the peptide is threaded through and
trapped within an N-terminalmacrolactamring. The structural characterization of
lasso structures and differentiation from their unthreaded topoisomers is not
trivial and generally requires the use of complementary biochemical and
spectroscopic methods. Here we investigated two antimicrobial peptides
belonging to the class II lasso peptide family and their corresponding
unthreaded topoisomers: microcin J25 (MccJ25), which is known to yield
two-peptide product ions specific of the lasso structure under collisioninduced
dissociation (CID), and capistruin, for which CID does not permit to
unambiguously assign the lasso structure. The two pairs of topoisomers were
analyzed by electrospray ionization Fourier transform ion cyclotron resonance
mass spectrometry (ESI-FTICR MS) upon CID, infrared multiple photon
dissociation (IRMPD), and electron capture dissociation (ECD). CID and
ECDspectra clearly permitted to differentiate MccJ25 from its non-lasso
topoisomer MccJ25-Icm, while for capistruin, only ECD was informative and
showed different extent of hydrogen migration (formation of c\bullet/z from
c/z\bullet) for the threaded and unthreaded topoisomers. The ECD spectra of the
triply-charged MccJ25 and MccJ25-lcm showed a series of radical b-type product
ions {\eth}b0In{\TH}. We proposed that these ions are specific of
cyclic-branched peptides and result from a dual c/z\bullet and y/b
dissociation, in the ring and in the tail, respectively. This work shows the
potentiality of ECD for structural characterization of peptide topoisomers, as
well as the effect of conformation on hydrogen migration subsequent to electron
capture
Consistent model of magnetism in ferropnictides
The discovery of superconductivity in LaFeAsO introduced the ferropnictides
as a major new class of superconducting compounds with critical temperatures
second only to cuprates. The presence of magnetic iron makes ferropnictides
radically different from cuprates. Antiferromagnetism of the parent compounds
strongly suggests that superconductivity and magnetism are closely related.
However, the character of magnetic interactions and spin fluctuations in
ferropnictides, in spite of vigorous efforts, has until now resisted
understanding within any conventional model of magnetism. Here we show that the
most puzzling features can be naturally reconciled within a rather simple
effective spin model with biquadratic interactions, which is consistent with
electronic structure calculations. By going beyond the Heisenberg model, this
description explains numerous experimentally observed properties, including the
peculiarities of the spin wave spectrum, thin domain walls, crossover from
first to second order phase transition under doping in some compounds, and
offers new insight in the occurrence of the nematic phase above the
antiferromagnetic phase transition.Comment: 5 pages, 3 figures, revtex
Recommended from our members
Camelina: Seed Yield Response to Applied Nitrogen and Sulfur
Camelina (Camelina sativa L. Crantz) has received worldwide attention in recent years as a biofuel crop and as a broadleaf option in cereal-based cropping systems. The objective of our 3-year study was to determine camelina seed yield and nitrogen use efficiency (NUE) as affected by six applied nitrogen (N) rates at four rainfed sites in the Pacific Northwest (PNW) of the United States. An N + sulfur (S) variable was also included. Seed oil content as affected by applied N and S was also evaluated in 2010. The four sites and their average annual crop-year precipitation during the three years were Lind, WA (228 mm); Pendleton, OR (421 mm); Moscow/Pullman, ID (695 mm); and Corvallis, OR (1085). The majority of precipitation occurs in the winter and summers are comparatively dry. Camelina responded differently to applied N among sites based upon precipitation and available soil N. Seed yield did not respond to N rate treatments at Lind, presumably due to sufficient soil residual N and limited precipitation. Seed yield increased with applied N at Pendleton, Moscow/Pullman, and Corvallis. Optimum applied N rates ranged from 0 to 90 kg ha-1 depending on annual precipitation and soil available N. Maximum seed yield increases attributable to applied N ranged from 19% at Pendleton to 93% at Moscow/Pullman. Camelina NUE was greatest at Moscow/Pullman although it decreased gradually with increasing applied N rates at all sites. Lind, Pendleton, and Corvallis had the same NUE of -0.06 kg seed for every kg of available N. Camelina did not respond to applied S at any site. Seed oil content was not affected by applied N or S. Based upon the results of this study, camelina requires about 12 kg N ha⁻¹ per 100 kg of expected seed yield.Keywords: Sustainable energy, Pacific Northwest USA, Nitrogen use efficiency, Biofuel crops, Dryland cropping systems, Camelin
Recommended from our members
Camelina: Planting date and method effects on stand establishment and seed yield
There has been keen interest in camelina (Camelina sativa L. Crantz) in recent years due to the unique fatty acid composition of the seed oil for human and animal consumption and, more importantly, the value of the seed oil to provide “green energy” to fuel commercial and military aircraft. The objective of our research was to evaluate several planting dates and two planting methods for camelina stand establishment and seed yield. Field experiments were conducted for three years at four distinct rainfed agro-environments in the Pacific Northwest, USA. Average crop-year precipitation at the sites during the three years was: Lind WA, 228 mm; Pendleton OR, 421 mm; Moscow ID (one year only), 760 mm; and Corvallis OR, 993 mm. Camelina was planted on an average of five dates at each site (n = 55) from early October to mid April at a rate of 6 kg/ha by either drilling seed at a shallow depth or broadcasting seed on the soil surface. Although camelina has excellent cold hardiness, the best plant stands were achieved with the late-winter and early-spring plantings. Four divergent planting date yield responses across sites were: no yield differences at Lind; increased yield with later planting dates at Pendleton; reduced yield with later plantings at Moscow (one year data); and a curvilinear response at Corvallis with the lowest yields from plantings in early fall and those after March 1 and highest yields from late-fall and mid-winter plantings. Both drilling and broadcast were effective for planting camelina with no overall advantage of either method. Seed yields ranged from <100 kg/ha during an extreme drought year at Lind to 2900 kg/ha at Moscow. Averaged across the four Pacific Northwest agro-environments in this study, we recommend: (i) late February–early March as the best overall planting date because of optimum stands and seed yield and having effective control of winter-annual broadleaf weeds with herbicide applied just prior to planting, and (ii) the broadcast method of planting as it generally equaled or slightly exceeded drilling for plant stand establishment and seed yield and can be accomplished more quickly at less expense.Keywords: Sustainable energy, Pacific Northwest USA, Biofuel crops, Dryland cropping system
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