6,082 research outputs found
LInKs "Lifting Independent Keypoints" -- Partial Pose Lifting for Occlusion Handling with Improved Accuracy in 2D-3D Human Pose Estimation
We present LInKs, a novel unsupervised learning method to recover 3D human
poses from 2D kinematic skeletons obtained from a single image, even when
occlusions are present. Our approach follows a unique two-step process, which
involves first lifting the occluded 2D pose to the 3D domain, followed by
filling in the occluded parts using the partially reconstructed 3D coordinates.
This lift-then-fill approach leads to significantly more accurate results
compared to models that complete the pose in 2D space alone. Additionally, we
improve the stability and likelihood estimation of normalising flows through a
custom sampling function replacing PCA dimensionality reduction previously used
in prior work. Furthermore, we are the first to investigate if different parts
of the 2D kinematic skeleton can be lifted independently which we find by
itself reduces the error of current lifting approaches. We attribute this to
the reduction of long-range keypoint correlations. In our detailed evaluation,
we quantify the error under various realistic occlusion scenarios, showcasing
the versatility and applicability of our model. Our results consistently
demonstrate the superiority of handling all types of occlusions in 3D space
when compared to others that complete the pose in 2D space. Our approach also
exhibits consistent accuracy in scenarios without occlusion, as evidenced by a
7.9% reduction in reconstruction error compared to prior works on the Human3.6M
dataset. Furthermore, our method excels in accurately retrieving complete 3D
poses even in the presence of occlusions, making it highly applicable in
situations where complete 2D pose information is unavailable
Unsupervised Reconstruction of 3D Human Pose Interactions From 2D Poses Alone
Current unsupervised 2D-3D human pose estimation (HPE) methods do not work in
multi-person scenarios due to perspective ambiguity in monocular images.
Therefore, we present one of the first studies investigating the feasibility of
unsupervised multi-person 2D-3D HPE from just 2D poses alone, focusing on
reconstructing human interactions. To address the issue of perspective
ambiguity, we expand upon prior work by predicting the cameras' elevation angle
relative to the subjects' pelvis. This allows us to rotate the predicted poses
to be level with the ground plane, while obtaining an estimate for the vertical
offset in 3D between individuals. Our method involves independently lifting
each subject's 2D pose to 3D, before combining them in a shared 3D coordinate
system. The poses are then rotated and offset by the predicted elevation angle
before being scaled. This by itself enables us to retrieve an accurate 3D
reconstruction of their poses. We present our results on the CHI3D dataset,
introducing its use for unsupervised 2D-3D pose estimation with three new
quantitative metrics, and establishing a benchmark for future research
Nonlocality of Hardy type in experiments using independent particle sources
By applying Hardy's argument, we demonstrate the violation of local realism
in a gedanken experiment using independent and separated particle sources.Comment: 9 pages, 1 fig, revtex, title change
Differential Adjuvant Activities of TLR7 and TLR9 Agonists Inversely Correlate with Nitric Oxide and PGE2 Production
Activation of different pattern recognition receptors causes distinct profiles of innate immune responses, which in turn dictate the adaptive immune response. We found that mice had higher CD4+ T cell expansion to an immunogen, ovalbumin, when coadministered with CpG than with CL097 in vivo. To account for this differential adjuvanticity, we assessed the activities of CpG and CL097 on antigen-specific CD4+ T cell expansion in vitro using an OT-II CD4+ T cell/bone marrow-derived dendritic cell (DC) co-culture system. Unexpectedly, ovalbumin-stimulated expansion of OT-II CD4+ T cells in vitro was potently suppressed by both TLR agonists, with CL097 being stronger than CpG. The suppression was synergistically reversed by co-inhibition of cyclooxygenases 1 and 2, and inducible nitric oxide (NO) synthase. In addition, stimulation of OT-II CD4+ T cell/DC cultures with CL097 induced higher levels of CD4+ T cell death than stimulation with CpG, and this CD4+ T cell turnover was reversed by NO and PGE2 inhibition. Consistently, the co-cultures stimulated with CL097 produced higher levels of prostaglandin E2 (PGE2) and NO than stimulation with CpG. CL097 induced higher PGE2 production in DC cultures and higher IFN-gamma in the OT-II CD4+ T cell/DC cultures, accounting for the high levels of PGE2 and NO. This study demonstrates that the adjuvant activities of immunostimulatory molecules may be determined by differential induction of negative regulators, including NO and PGE2 suppressing clonal expansion and promoting cell death of CD4+ T cells
Non-equilibrium Plasmons in a Quantum Wire Single Electron Transistor
We analyze a single electron transistor composed of two semi-infinite one
dimensional quantum wires and a relatively short segment between them. We
describe each wire section by a Luttinger model, and treat tunneling events in
the sequential approximation when the system's dynamics can be described by a
master equation. We show that the steady state occupation probabilities in the
strongly interacting regime depend only on the energies of the states and
follow a universal form that depends on the source-drain voltage and the
interaction strength.Comment: 4 pages, 3 figures. To appear in the Phys. Rev. Let
New directions for the treatment of adrenal insufficiency
The following funding bodies supported this work: Biotechnology and Biological Sciences Research Council (BBSRC BB/L00267/1, to LG), Rosetrees Trust (to LG), Barts and The London Charity (417/2235, to LG), EU COFUND (PCOFUND-GA-2013-608765, to LG and GRB). IH is supported by a Medical Research Council (MRC, G0802796) PhD studentship
Report on the Findings of the 2004 Australian National eProcurement Survey
This report highlights the key findings from the 2004 Australian National eProcurement Survey. The aim of the 2004 Australian National eProcurement Survey is to establish the nature, extent and adoption profile of eProcurement strategies and processes of Australian organisations.Australian Research Council (Grant No. LP0214841
Report on the Findings of the 2004 Australian National eProcurement Survey
This report highlights the key findings from the 2004 Australian National eProcurement Survey. The aim of the 2004 Australian National eProcurement Survey is to establish the nature, extent and adoption profile of eProcurement strategies and processes of Australian organisations.Australian Research Council (Grant No. LP0214841
Synthesis of N-arylpyridinium salts bearing a nitrone spin trap as potential mitochondria-targeted antioxidants
The generation of excess reactive oxygen species (ROS) in mitochondria is responsible for much of the oxidative stress associated with ageing (aging), and mitochondrial dysfunction is part of the pathology of neurodegeneration and type 2 diabetes. Lipophilic pyridinium ions are known to accumulate in mitochondria and this paper describes a general route for the preparation of nitrone-containing N-arylpyridinium salts having a range of lipophilicities, as potential therapeutic antioxidants. The compatibility of nitrones with the Zincke reaction is the key to their synthesis. Their trapping of carbon-centred radicals and the EPR spectra of the resulting nitroxides are reported
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