2,013 research outputs found
Multi-person 3D pose estimation from unlabelled data
Its numerous applications make multi-human 3D pose estimation a remarkably
impactful area of research. Nevertheless, assuming a multiple-view system
composed of several regular RGB cameras, 3D multi-pose estimation presents
several challenges. First of all, each person must be uniquely identified in
the different views to separate the 2D information provided by the cameras.
Secondly, the 3D pose estimation process from the multi-view 2D information of
each person must be robust against noise and potential occlusions in the
scenario. In this work, we address these two challenges with the help of deep
learning. Specifically, we present a model based on Graph Neural Networks
capable of predicting the cross-view correspondence of the people in the
scenario along with a Multilayer Perceptron that takes the 2D points to yield
the 3D poses of each person. These two models are trained in a self-supervised
manner, thus avoiding the need for large datasets with 3D annotations
Multi-camera Torso Pose Estimation using Graph Neural Networks
Estimating the location and orientation of humans is an essential skill for service and assistive robots. To achieve a reliable estimation in a wide area such as an apartment, multiple RGBD cameras are frequently used. Firstly, these setups are relatively expensive. Secondly, they seldom perform an effective data fusion using the multiple camera sources at an early stage of the processing pipeline. Occlusions and partial views make this second point very relevant in these scenarios. The proposal presented in this paper makes use of graph neural networks to merge the information acquired from multiple camera sources, achieving a mean absolute error below 125 mm for the location and 10 degrees for the orientation using low-resolution RGB images. The experiments, conducted in an apartment with three cameras, benchmarked two different graph neural network implementations and a third architecture based on fully connected layers. The software used has been released as open-source in a public repository
IRAS 11590-6452 in BHR 71 - a binary protostellar system?
New AAT near-infrared and SEST 12CO J=2-1 observations are combined with
existing ISO mid-infrared and ATCA cm radio continuum observations to examine
the protostellar content of the Bok globule BHR 71. Together with observations
of Herbig-Haro objects, these data show: (1) Two protostellar sources, IRS1 and
IRS2, with a separation of ~17 arcsec (3400 AU) are located within BHR 71. (2)
Each protostar is driving its own molecular outflow. The outflow from IRS1 is
much larger in extent, is more massive, and dominates the CO emission. (3) Both
protostars are associated with Herbig-Haro objects and shock excited 2.122
micron H2 v=1-0S(1) emission, which coincide spatially with their CO outflows.
(4) IRS1 is associated with cm continuum emission, with a flat or rising
spectrum which is consistent with free-free emission, a signpost of
protostellar origin.Comment: 12 pages, 2 figures (colour), accepted by ApJ Letters. See also
http://cfa-www.harvard.edu/~bourke
Mopra line survey mapping of NGC6334I and I(N) at 3mm
A 5'x5' region encompassing NGC6334I and I(N) has been mapped at a wavelength
of 3mm (from 83.5 to 115.5GHz) with the Mopra telescope at an angular
resolution between 33 arcsec and 36 arcsec. This investigation has made use of
the recently installed 3mm MMIC receiver and the Mopra Spectrometer (MOPS) with
broadband capabilities permitting total coverage of the entire frequency range
with just five different observations. In total, the spatial distribution of
nineteen different molecules, ions and radicals, along with additional selected
isotopologues have been studied. Whilst most species trace the sites of star
formation, CH_3CN appears to be most closely associated with NGC6334I and I(N).
Both CN and C_2H appear to be widespread, tracing gas that is not associated
with active star formation. Both N_2H^+ and HC_3N closely resemble dust
continuum emission, showing they are reliable tracers of dense material, as
well as the youngest stages of high mass star formation. Hot (E_u/k>100K)
thermal CH_3OH emission is preferentially found towards NGC6334I, contrasting
with I(N), where only cold (E_u/k<22K) thermal CH_3OH emission is found.Comment: Accepted by MNRA
Il-15 enhances the persistence and function of bcma-targeting car-t cells compared to il-2 or il-15/il-7 by limiting car-t cell dysfunction and differentiation
Chimeric antigen receptor (CAR)-T cell immunotherapy has revolutionized the treatment of B-lymphoid malignancies. For multiple myeloma (MM), B-cell maturation antigen (BCMA)-targeted CAR-T cells have achieved outstanding complete response rates, but unfortunately, patients often relapse within a year of receiving the therapy. Increased persistence and reduced dysfunction are crucial features that enhance the durability of CAR-T cell responses. One of the factors that influence CAR-T cell in vivo longevity and loss of function, but which has not yet been extensively studied for BCMA-directed CAR-T cells, are the cytokines used during their production. We here compared the impact of IL-2, IL-15 and a combination of IL-15/IL-7 on the phenotype and function of ARI2h, an academic BCMA-directed CAR-T cell that is currently being administered to MM patients. For this study, flow cytometry, in vitro cytotoxicity assays and analysis of cytokine release were performed. In addition, ARI2h cells expanded with IL-2, IL-15, or IL-15/IL-7 were injected into MM tumor-bearing mice to assess their in vivo efficacy. We demonstrated that each of the cytokine conditions was suitable for the expansion of ARI2h cells, with clear in vitro activity. Strikingly, however, IL-15-produced ARI2h cells had improved in vivo efficacy and persistence. When explored further, it was found that IL-15 drove a less-differentiated ARI2h phenotype, ameliorated parameters related to CAR-T cell dysfunction, and lowered the release of cytokines potentially involved in cytokine release syndrome and MM progression. Moreover, we observed that IL-15 was less potent in inducing T cell senescence and DNA damage accumulation, both of which may contribute to an unfavorable CAR-T cell phenotype. These findings show the superiority of IL-15 to IL-2 and IL-15/IL-7 in the quality of anti-BCMA CAR-T cells, particularly their efficacy and persistence, and as such, could improve the duration of responses if applied to the clinical production of CAR-T cells for patients
The function of remote sensing in support of environmental policy
Limited awareness of environmental remote sensingâs potential ability to support environmental policy development constrains the technologyâs utilization. This paper reviews the potential of earth observation from the perspective of environmental policy. A literature review of âremote sensing and policyâ revealed that while the number of publications in this field increased almost twice as rapidly as that of remote sensing literature as a whole (15.3 versus 8.8% yrâ1), there is apparently little academic interest in the societal contribution of environmental remote sensing. This is because none of the more than 300 peer reviewed papers described actual policy support. This paper describes and discusses the potential, actual support, and limitations of earth observation with respect to supporting the various stages of environmental policy development. Examples are given of the use of remote sensing in problem identification and policy formulation, policy implementation, and policy control and evaluation. While initially, remote sensing contributed primarily to the identification of environmental problems and policy implementation, more recently, interest expanded to applications in policy control and evaluation. The paper concludes that the potential of earth observation to control and evaluate, and thus assess the efficiency and effectiveness of policy, offers the possibility of strengthening governance
New Energy Calibration of the CMAM 5MV Tandem Accelerator
Abstract Ion accelerators are fundamental in the ongoing research on materials for future energy sources, being the primary tool for understanding the behaviour of different classes of materials (functional, structural, diagnostic) under e.g. the intense radiation expected in fission reactors or the critical thermal operational conditions in IV generation fission reactors. The relevance of ion accelerators research extends straightforwardly to the modification and analysis of materials to be used in future developments of diverse non-nuclear sources like photovoltaic, fuel batteries, etc. From the analytical point of view, the energy of the accelerated ion needs, in many cases, to be known with a precision higher than e.g. the width of reaction resonances that are used for controlling either the yield of a reaction or the penetration depth of the ion, imposing a calibration of the accelerator terminal voltage. This paper reports on the new energy calibration performed for the 5 MV CMAM tandem accelerator
Spitzer observations of HH54 and HH7-11: mapping the H2 ortho-to-para ratio in shocked molecular gas
We report the results of spectroscopic mapping observations carried out
toward the Herbig-Haro objects HH7-11 and HH54 over the 5.2 - 37 micron region
using the Infrared Spectrograph of the Spitzer Space Telescope. These
observations have led to the detection and mapping of the S(0) - S(7) pure
rotational lines of molecular hydrogen, together with emissions in fine
structure transitions of Ne+, Si+, S, and Fe+. The H2 rotational emissions
indicate the presence of warm gas with a mixture of temperatures in the range
400 - 1200 K, consistent with the expected temperature behind nondissociative
shocks of velocity ~ 10 - 20 km/s, while the fine structure emissions originate
in faster shocks of velocity 35 - 90 km/s that are dissociative and ionizing.
Maps of the H2 line ratios reveal little spatial variation in the typical
admixture of gas temperatures in the mapped regions, but show that the H2
ortho-to-para ratio is quite variable, typically falling substantially below
the equilibrium value of 3 attained at the measured gas temperatures. The
non-equilibrium ortho-to-para ratios are characteristic of temperatures as low
as ~ 50 K, and are a remnant of an earlier epoch, before the gas temperature
was elevated by the passage of a shock. Correlations between the gas
temperature and H2 ortho-to-para ratio show that ortho-to-para ratios < 0.8 are
attained only at gas temperatures below ~ 900 K; this behavior is consistent
with theoretical models in which the conversion of para- to ortho-H2 behind the
shock is driven by reactive collisions with atomic hydrogen, a process which
possesses a substantial activation energy barrier (E_A/k ~ 4000 K) and is
therefore very inefficient at low temperature.Comment: 45 pages, including 16 figures. Accepted for publication in Ap
Waves on the surface of the Orion molecular cloud
Massive stars influence their parental molecular cloud, and it has long been
suspected that the development of hydrodynamical instabilities can compress or
fragment the cloud. Identifying such instabilities has proved difficult. It has
been suggested that elongated structures (such as the `pillars of creation')
and other shapes arise because of instabilities, but alternative explanations
are available. One key signature of an instability is a wave-like structure in
the gas, which has hitherto not been seen. Here we report the presence of
`waves' at the surface of the Orion molecular cloud near where massive stars
are forming. The waves seem to be a Kelvin-Helmholtz instability that arises
during the expansion of the nebula as gas heated and ionized by massive stars
is blown over pre-existing molecular gas.Comment: Preprint of publication in Natur
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