252 research outputs found

    Learning based automatic face annotation for arbitrary poses and expressions from frontal images only

    Get PDF
    Statistical approaches for building non-rigid deformable models, such as the active appearance model (AAM), have enjoyed great popularity in recent years, but typically require tedious manual annotation of training images. In this paper, a learning based approach for the automatic annotation of visually deformable objects from a single annotated frontal image is presented and demonstrated on the example of automatically annotating face images that can be used for building AAMs for fitting and tracking. This approach employs the idea of initially learning the correspondences between landmarks in a frontal image and a set of training images with a face in arbitrary poses. Using this learner, virtual images of unseen faces at any arbitrary pose for which the learner was trained can be reconstructed by predicting the new landmark locations and warping the texture from the frontal image. View-based AAMs are then built from the virtual images and used for automatically annotating unseen images, including images of different facial expressions, at any random pose within the maximum range spanned by the virtually reconstructed images. The approach is experimentally validated by automatically annotating face images from three different databases

    Hadronic contribution to the muon g-2: a Dyson-Schwinger perspective

    Full text link
    We summarize our results for hadronic contributions to the anomalous magnetic moment of the muon (aμa_\mu), the one from hadronic vacuum-polarisation (HVP) and the light-by-light scattering contribution (LBL), obtained from the Dyson-Schwinger equations (DSE's) of QCD. In the case of HVP we find good agreement with model independent determinations from dispersion relations for aμHVPa_\mu^\mathrm{HVP} as well as for the Adler function with deviations well below the ten percent level. From this we conclude that the DSE approach should be capable of describing aμLBLa_\mu^\mathrm{LBL} with similar accuracy. We also present results for LBL using a resonance expansion of the quark anti-quark T-matrix. Our preliminary value is aμLBL=(217±91)×10−11a_\mu^\mathrm{LBL}=(217 \pm 91) \times 10^{-11}.Comment: Contribution to the proceedings of 'International school of nuclear physics, 33rd course', Erice-Sicily: 16 - 24 September 201

    Removal of xenoantigenic glycosylation patterns from porcine pulmonary heart valve matrices is dependent of the applied decellularization method

    Get PDF
    Department of Cardiac-, Thoracic-, Transplantation and Vascular Surgery, Hannover Medical School, Hannover Germany and Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Hannover Medical School, Hannover, Germany, The 6th International Medical Congress for Students and Young Doctors, May 12-14, 2016Introduction: Matrix guided tissue regeneration (GTR) based on allogeneic decellularized matrices has been shown as an overall convincing method for heart valve replacement. Nevertheless, a substantial donor shortage prevents an unlimited clinical application of human GTR-valves. Utilization of porcine decellularized heart valve matrices could offer a possible solution for overcoming this considerable limitation. In the past, implantation of xenogeneic valve tissues considered to be acellularinto human recipients, however, mostly lead to severe immune responses usually ending up into graft rejection. This study addresses the question whether potential xenoantigenic glycosylation of extracellular matrix components, like the major xenoantigen α-Gal, which served as model epitope for this study, can be removed by adjusted decellularization procedures. Materials and methods: Fresh porcine pulmonary heart valve conduits were decellularized by application of different detergent- and enzyme-based decellularization protocols. Subsequent cleavage of remaining matrix-related α-Gal epitopes was performed by enzymatic deglycosylation treatment on matrix samples of each decellularization group. Resulting tissues, mainly composed from insoluble extracellular matrix proteins, were afterwards divided into the relevant sections pulmonary artery wall specimens and pulmonary valve leaflets, frozen in liquid nitrogen, minced and finally solubilized by protease digestion. Evaluation of thus prepared solutions regarding to α-Gal contents was finally performed using a novel designed lectin-based immunoblot technique. Discussion results: Sole decellularization lead to significant removal of α-Gal, substantial varying in strong dependency to applied protocols between 30 to 50% compared to α-Gal contents of porcine native control tissues. An additional decrease of residual α-Gal in a range of another 15 to 30% was achievable by additional α-Galactosidase treatment. Combining decellularization and subsequent enzymatic digestion resulted in reductions of matrix related α-Gal contents down to levels, which could be measured for respective pulmonary valve tissues of α-Gal-KnockOut pigs. Conclusion: Residual xenoantigenic carbohydrates are detectable on insoluble matrix components of porcine pulmonary heart valves, substantially varying dependent on applied decellularization protocols. Combined with glycolytic digestions, remaining glycosylation contents are reducible to background levels. Impacts of these novel insights have to be evaluated in further in vitro as well as in vivo studies

    Investigating word affect features and fusion of probabilistic predictions incorporating uncertainty in AVEC 2017

    Full text link
    © 2017 Association for Computing Machinery. Predicting emotion intensity and severity of depression are both challenging and important problems within the broader field of affective computing. As part of the AVEC 2017, we developed a number of systems to accomplish these tasks. In particular, word affect features, which derive human affect ratings (e.g. arousal and valence) from transcripts, were investigated for predicting depression severity and liking, showing great promise. A simple system based on the word affect features achieved an RMSE of 6.02 on the test set, yielding a relative improvement of 13.6% over the baseline. For the emotion prediction sub-challenge, we investigated multimodal fusion, which incorporated a measure of uncertainty associated with each prediction within an Output-Associative fusion framework for arousal and valence prediction, whilst liking prediction systems mainly focused on text-based features. Our best emotion prediction systems provided significant relative improvements over the baseline on the test set of 39.5%, 17.6%, and 29.3% for arousal, valence, and liking. Of particular note is that consistent improvements were observed when incorporating prediction uncertainty across various system configurations for predicting arousal and valence, suggesting the importance of taking into consideration prediction uncertainty for fusion and more broadly the advantages of probabilistic predictions

    Structure and deformation of the Kermadec forearc in response to subduction of the Pacific oceanic plate

    Get PDF
    The Tonga-Kermadec forearc is deforming in response to on-going subduction of the Pacific Plate beneath the Indo-Australian Plate. Previous research has focussed on the structural development of the forearc where large bathymetric features such as the Hikurangi Plateau and Louisville Ridge seamount chain are being subducted. Consequently, knowledge of the ‘background’ forearc in regions of normal plate convergence is limited. We report on an ∼250-km-long multichannel seismic reflection profile that was shot perpendicular to the Tonga-Kermadec trench at ∼28°S to determine the lateral and temporal variations in the structure, stratigraphy and deformation of the Kermadec forearc resulting solely from Pacific Plate subduction. Interpretation of the seismic profile, in conjunction with regional swath bathymetry data, shows that the Pacific Plate exhibits horst and graben structures that accommodate bending-induced extensional stresses, generated as the trenchward dip of the crust increases. Trench infill is also much thicker than expected at 1 km which, we propose, results from increased sediment flux into and along the trench. Pervasive normal faulting of the mid-trench slope most likely accommodates the majority of the observed forearc extension in response to basal subduction erosion, and a structural high is located between the mid- and upper-trench slopes. We interpret this high as representing a dense and most likely structurally robust region of crust lying beneath this region. Sediment of the upper-trench slope documents depositional hiatuses and on-going uplift of the arc. Strong along-arc currents appear to erode the Kermadec volcanic arc and distribute this sediment to the surrounding basins, while currents over the forearc redistribute deposits as sediment waves. Minor uplift of the transitional Kermadec forearc, observed just to the north of the profile, appears to relate to an underlying structural trend as well as subduction of the Louisville Ridge seamount chain 250 km to the north. Relative uplift of the Kermadec arc is observed from changes in the tilt of upper-trench slope deposits and extensional faulting of the basement immediately surrounding the Louisville Ridge

    Implications of LHC Searches on SUSY Particle Spectra: The pMSSM Parameter Space with Neutralino Dark Matter

    Full text link
    We study the implications of LHC searches on SUSY particle spectra using flat scans of the 19-parameter pMSSM phase space. We apply constraints from flavour physics, g_mu-2, dark matter and earlier LEP and Tevatron searches. The sensitivity of the LHC SUSY searches with jets, leptons and missing energy is assessed by reproducing with fast simulation the recent CMS analyses after validation on benchmark points. We present results in terms of the fraction of pMSSM points compatible with all the constraints which are excluded by the LHC searches with 1 fb^{-1} and 15 fb^{-1} as a function of the mass of strongly and weakly interacting SUSY particles. We also discuss the suppression of Higgs production cross sections for the MSSM points not excluded and contrast the region of parameter space tested by the LHC data with the constraints from dark matter direct detection experiments.Comment: 14 pages, 13 figures. v2: increased statistics, to appear in EPJ

    Hadronic Contributions to the Muon Anomaly in the Constituent Chiral Quark Model

    Get PDF
    The hadronic contributions to the anomalous magnetic moment of the muon which are relevant for the confrontation between theory and experiment at the present level of accuracy, are evaluated within the same framework: the constituent chiral quark model. This includes the contributions from the dominant hadronic vacuum polarization as well as from the next--to--leading order hadronic vacuum polarization, the contributions from the hadronic light-by-light scattering, and the contributions from the electroweak hadronic ZγγZ\gamma\gamma vertex. They are all evaluated as a function of only one free parameter: the constituent quark mass. We also comment on the comparison between our results and other phenomenological evaluations.Comment: Several misprints corrected and a clarifying sentence added. Three figures superposed and two references added. Version to appear in JHE

    Decellularized tissue engineered pericardium as replacement for tricuspid valve in cardiac surgery

    Get PDF
    Department of Cardiac, Thoracic, Transplantation and Vascular Surgery, Hannover Medical School, Hannover Germany and Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Hannover Medical School, Hannover, Germany, The 6th International Medical Congress for Students and Young Doctors, May 12-14, 2016Introduction: Tricuspid valve replacement is the last treatment choice in tricuspid valve pathology. The choice to insert mechanical or bioprosthetic valve remains controversial. Both prostheses have some limitations such as infection, risk of thromboembolism, need for life-long anticoagulation or limited durability. The following study aimed to develop a novel tissue-engineered tricuspid valve based on decellularized pericardium allograft. Materials and methods: Fresh ovine pericardium was harvested at the local slaughter house and decellularized using detergents. For disinfection all samples were treated for 24h with Phosphate Buffered Solution supplemented with 1% gentamicin and 1% streptomycin. The effectiveness of decellularization was evaluated by histological staining (hematoxylin-eosin, Movat’s Pentachrom and Van Gieson), Isolectin B4 staining (a-gal xenoantigen) and by DNA-quantification. Two valvular leaflets were manufactured out of decellularized pericardium and sutured ex-vivo into the tricuspid annulus of an ovine heart and suspended on papillary muscles. Hydraulic test were performed to prove valve competency. Discussion results: After detergent treatment pericardial tissue has been converted in a cell-free scaffold as proven by standard histological analysis. Immunofluorescent examinations revealed the absence of a-gal xenoantigens. DNA-quantification showed a substantial reduction in DNA content compared to the normal tissue. The alignment of collagenous fibers in decellularized scaffolds appeared well-preserved and was not affected by detergent decellularization procedure as proven by histological staining. Graft disinfection and storage in antibiotic solution after decellularization did not affect the texture of the scaffold. Furthermore, two leaflet structure created out of decellularized pericardium and surgically sutured in tricuspid position of ovine heart resulted in a competent valve prosthesis. Conclusion: The present results have shown successful decellularization of the ovine pericardium using detergents. Decellularized pericardial allograft can be used in cardiac surgery as a scaffold for valvular tissue engineering or for in-vivo guided tissue regeneration in tricuspid valve replacement
    • …
    corecore