608 research outputs found
TMR: Text-to-Motion Retrieval Using Contrastive 3D Human Motion Synthesis
In this paper, we present TMR, a simple yet effective approach for text to 3D
human motion retrieval. While previous work has only treated retrieval as a
proxy evaluation metric, we tackle it as a standalone task. Our method extends
the state-of-the-art text-to-motion synthesis model TEMOS, and incorporates a
contrastive loss to better structure the cross-modal latent space. We show that
maintaining the motion generation loss, along with the contrastive training, is
crucial to obtain good performance. We introduce a benchmark for evaluation and
provide an in-depth analysis by reporting results on several protocols. Our
extensive experiments on the KIT-ML and HumanML3D datasets show that TMR
outperforms the prior work by a significant margin, for example reducing the
median rank from 54 to 19. Finally, we showcase the potential of our approach
on moment retrieval. Our code and models are publicly available.Comment: arXiv preprint, project page: https://mathis.petrovich.fr/tmr
SINC: Spatial Composition of 3D Human Motions for Simultaneous Action Generation
Our goal is to synthesize 3D human motions given textual inputs describing
simultaneous actions, for example 'waving hand' while 'walking' at the same
time. We refer to generating such simultaneous movements as performing 'spatial
compositions'. In contrast to temporal compositions that seek to transition
from one action to another, spatial compositing requires understanding which
body parts are involved in which action, to be able to move them
simultaneously. Motivated by the observation that the correspondence between
actions and body parts is encoded in powerful language models, we extract this
knowledge by prompting GPT-3 with text such as "what are the body parts
involved in the action ?", while also providing the parts list and
few-shot examples. Given this action-part mapping, we combine body parts from
two motions together and establish the first automated method to spatially
compose two actions. However, training data with compositional actions is
always limited by the combinatorics. Hence, we further create synthetic data
with this approach, and use it to train a new state-of-the-art text-to-motion
generation model, called SINC ("SImultaneous actioN Compositions for 3D human
motions"). In our experiments, that training with such GPT-guided synthetic
data improves spatial composition generation over baselines. Our code is
publicly available at https://sinc.is.tue.mpg.de/.Comment: ICCV 2023 Camera Read
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Thymic negative selection is functional in NOD mice
Based on analyses of multiple TCR transgenic (tg) models, the emergence of pathogenic T cells in diabetes-prone NOD mice has been ascribed to a failure to censure autoreactive clones in the thymus. In contrast, using isolated and preselected thymocytes, we show that nonobese diabetic (NOD) genetic variation impairs neither clonal deletion nor downstream transcriptional programs. However, we find that NOD genetic variation influences αβ/γδ-lineage decisions promoted by early expression of tg αβ-TCRs at the double-negative (DN) stage. In B6 and other genetic backgrounds, tg αβ-TCRs behave like γδ-TCRs and commit a large fraction of DNs toward the γδ-lineage, thereby decreasing the size of the double-positive (DP) pool, which is efficiently positively and negatively selected. In NOD DNs, αβ-TCR signalosomes instead behave like pre-TCRs, resulting in high numbers of DPs competing for limited selection niches, and poor positive and negative selection. Once niche effects are neutralized in mixed bone marrow chimeras, positive and negative selection are equally efficient on B6 and NOD backgrounds. Biochemical analysis revealed a selective defect in the activation of Erk1/2 downstream of NOD αβ-TCR signalosomes. Therefore, NOD genetic variation influences αβ/γδ-lineage decisions when the αβ-TCR heterodimer is prematurely expressed, but not the process of negative selection
Experimental method and statistical analysis to fit tumor growth model using SPECT/CT imaging: A preclinical study
Background: Over the last decade, several theoretical tumor-models have been developed to describe tumor growth. Oncology imaging is performed using various modalities including computed tomography (CT), magnetic resonance imaging (MRI), single-photon emission computed tomography (SPECT) and fluorodeoxyglucose-positron emission tomography (FDG-PET). Our goal is to extract useful, otherwise hidden, quantitative biophysical parameters (such as growth-rate, tumor-necrotic-factor, etc.) from these serial images of tumors by fitting mathematical models to images. These biophysical features are intrinsic to the tumor types and specific to the study-subject, and expected to add valuable information on the tumor containment or spread and help treatment plans. Thus, fitting realistic but practical models and assessing parameter-errors and degree of fit is important. Methods: We implemented an existing theoretical ode-compartment model and variants and applied them for the first time, in vivo. We developed an inversion algorithm to fit the models for tumor growth for simulated as well as in vivo experimental data. Serial SPECT/CT scans of mice breast-tumors were acquired, and SPECT data was used to segment the proliferating-layers of tumors. Results: Results of noisy data simulation and inversion show that 5 out of 7 parameters were recovered to within 4.3% error. In particular, tumor growth-rate parameter was recovered to 0.07% error. For model fitting to in vivo mice-tumors, regression analysis on the P-layer volume showed R2 of 0.99 for logistic and Gompertzian while surface area model yielded R2=0.96. For the necrotic layer the R2 values were 0.95, 0.93 and 0.94 respectively for surface-area, logistic and Gompertzian. The Akaike Information Criterion (AIC) weights of the models (giving their relative probability of being the best Kullback-Leibler (K-L) model among the set of candidate models) were 0, 0.43 and 0.57 for surface-area, logistic and Gompertzian models. Conclusions: Model-fitting to mice tumor studies demonstrates feasibility of applying the models to in vivo imaging data to extract features. Akaike information criterion (AIC) evaluations show Gompertzian or logistic growth model fits in vivo breast-tumors better than surface-area based growth model
CXCL12 retargeting of an adenovirus vector to cancer cells using a bispecific adapter
Ad vectors are promising delivery vehicles for cancer therapeutic interventions. However, their application is limited by promiscuous tissue tropism and hepatotoxicity. This limitation can be avoided by altering the native tropism of Ads so that they can be redirected to the target cells through alternate cellular receptors. The CXCR4 chemokine receptor belongs to a large superfamily of G-protein-coupled receptors and is known to be upregulated in a wide variety of cancers, including breast cancer and melanoma. These receptors have been associated with cancer cell survival, progression, and metastasis. In the current study, an Ad to cancer cells overexpressing CXCR4 by using a bispecific adapter, sCAR-CXCL12, was retargeted. The sCAR-CXCL12 adapter contained the soluble ectodomain form of the native Ad5 receptor (sCAR), which was fused to a mature human chemokine ligand, CXCL12, through a short peptide linker. A dramatic increase in the infectivity of cancer cells using a targeted Ad vector compared with an untargeted vector was observed. Furthermore, sCAR-CXCL12 attenuated Ad infection of liver ex vivo and in vivo and enhanced Ad vector infection of xenograft tumors implanted in immunodeficient SCID-bg mice. Thus, the sCAR-CXCL12 adapter could be used to retarget Ad vectors to chemokine receptor-positive tumors
The Spectral Energy Distribution of Self-gravitating Interstellar Clouds I. Spheres
We derive the spectral energy distribution (SED) of dusty, isothermal, self
gravitating, stable and spherical clouds externally heated by the ambient
interstellar radiation field. For a given radiation field and dust properties,
the radiative transfer problem is determined by the pressure of the surrounding
medium and the cloud mass expressed as a fraction of the maximum stable cloud
mass above which the clouds become gravitational unstable.
To solve the radiative transfer problem a ray-tracing code is used to
accurately derive the light distribution inside the cloud. This code considers
both non isotropic scattering on dust grains and multiple scattering events.
The dust properties inside the clouds are assumed to be the same as in the
diffuse interstellar medium in our galaxy. We analyse the effect of the
pressure, the critical mass fraction, and the ISRF on the SED and present
brightness profiles in the visible, the IR/FIR and the submm/mm regime with the
focus on the scattered emission and the thermal emission from PAH-molecules and
dust grains.Comment: accepted for publication in ApJS, May 2008, v176n1 issu
Reversal of experimental colitis disease activity in mice following administration of an adenoviral IL-10 vector
Genetic deficiency in the expression of interleukin-10 (IL-10) is associated with the onset and progression of experimental inflammatory bowel disease (IBD). The clinical significance of IL-10 expression is supported by studies showing that immune-augmentation of IL-10 prevents inflammation and mucosal damage in animal models of colitis and in human colitis. Interleukin-10 (IL-10), an endogenous anti-inflammatory and immunomodulating cytokine, has been shown to prevent some inflammation and injury in animal and clinical studies, but the efficacy of IL-10 treatment remains unsatisfactory. We found that intra-peritoneal administration of adenoviral IL-10 to mice significantly reversed colitis induced by administration of 3% DSS (dextran sulfate), a common model of colitis. Adenoviral IL-10 (Ad-IL10) transfected mice developed high levels of IL-10 (394 +/- 136 pg/ml) within the peritoneal cavity where the adenovirus was expressed. Importantly, when given on day 4 (after the induction of colitis w/DSS), Ad-IL10 significantly reduced disease activity and weight loss and completely prevented histopathologic injury to the colon at day 10. Mechanistically, compared to Ad-null and DSS treated mice, Ad-IL10 and DSS-treated mice were able to suppress the expression of MAdCAM-1, an endothelial adhesion molecule associated with IBD. Our results suggest that Ad-IL10 (adenoviral IL-10) gene therapy of the intestine or peritoneum may be useful in the clinical treatment of IBD, since we demonstrated that this vector can reverse the course of an existing gut inflammation and markers of inflammation
Fast Mapping of Terahertz Bursting Thresholds and Characteristics at Synchrotron Light Sources
Dedicated optics with extremely short electron bunches enable synchrotron
light sources to generate intense coherent THz radiation. The high degree of
spatial compression in this so-called low-alpha optics entails a complex
longitudinal dynamics of the electron bunches, which can be probed studying the
fluctuations in the emitted terahertz radiation caused by the micro-bunching
instability ("bursting"). This article presents a "quasi-instantaneous" method
for measuring the bursting characteristics by simultaneously collecting and
evaluating the information from all bunches in a multi-bunch fill, reducing the
measurement time from hours to seconds. This speed-up allows systematic studies
of the bursting characteristics for various accelerator settings within a
single fill of the machine, enabling a comprehensive comparison of the measured
bursting thresholds with theoretical predictions by the bunched-beam theory.
This paper introduces the method and presents first results obtained at the
ANKA synchrotron radiation facility.Comment: 7 pages, 7 figures, to be published in Physical Review Accelerators
and Beam
Genetic predisposition may not improve prediction of cardiac surgery-associated acute kidney injury
Background: The recent integration of genomic data with electronic health records has enabled large scale genomic studies on a variety of perioperative complications, yet genome-wide association studies on acute kidney injury have been limited in size or confounded by composite outcomes. Genome-wide association studies can be leveraged to create a polygenic risk score which can then be integrated with traditional clinical risk factors to better predict postoperative complications, like acute kidney injury.Methods: Using integrated genetic data from two academic biorepositories, we conduct a genome-wide association study on cardiac surgery-associated acute kidney injury. Next, we develop a polygenic risk score and test the predictive utility within regressions controlling for age, gender, principal components, preoperative serum creatinine, and a range of patient, clinical, and procedural risk factors. Finally, we estimate additive variant heritability using genetic mixed models.Results: Among 1,014 qualifying procedures at Vanderbilt University Medical Center and 478 at Michigan Medicine, 348 (34.3%) and 121 (25.3%) developed AKI, respectively. No variants exceeded genome-wide significance (p < 5 × 10−8) threshold, however, six previously unreported variants exceeded the suggestive threshold (p < 1 × 10−6). Notable variants detected include: 1) rs74637005, located in the exonic region of NFU1 and 2) rs17438465, located between EVX1 and HIBADH. We failed to replicate variants from prior unbiased studies of post-surgical acute kidney injury. Polygenic risk was not significantly associated with post-surgical acute kidney injury in any of the models, however, case duration (aOR = 1.002, 95% CI 1.000–1.003, p = 0.013), diabetes mellitus (aOR = 2.025, 95% CI 1.320–3.103, p = 0.001), and valvular disease (aOR = 0.558, 95% CI 0.372–0.835, p = 0.005) were significant in the full model.Conclusion: Polygenic risk score was not significantly associated with cardiac surgery-associated acute kidney injury and acute kidney injury may have a low heritability in this population. These results suggest that susceptibility is only minimally influenced by baseline genetic predisposition and that clinical risk factors, some of which are modifiable, may play a more influential role in predicting this complication. The overall impact of genetics in overall risk for cardiac surgery-associated acute kidney injury may be small compared to clinical risk factors
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Circulating C3 is Necessary and Sufficient for Induction of Autoantibody-Mediated Arthritis in a Mouse Model
Objective. For the inflammation characteristic of rheumatoid arthritis, the relative contribution of mediators produced locally in the synovium versus those circulating systemically is unknown. Complement factor C3 is made in rheumatoid synovium and has been proposed to be a crucial driver of inflammation. The aim of this study was to test, in a mouse model of rheumatoid arthritis, whether C3 synthesized within the synovium is important in promoting inflammation. Methods. Radiation bone marrow chimeras between normal and C3−/− mice were constructed in order to generate animals that expressed or lacked expression of C3 only in hematopoietic cells. Parabiotic mice were made by surgically linking C3−/− mice to irradiated wild-type mice to obtain animals having C3 only in the circulation. Arthritis was induced by injection of serum from arthritic K/BxN mice.Results In bone marrow chimeras, synthesis of C3 by radioresistant cells was necessary and sufficient to confer susceptibility to serum-transferred arthritis. Parabionts having C3 only in the circulation remained sensitive to arthritis induction, and the cartilage of these arthritic mice contained deposits of C3. Conclusion. In a mouse model in which the alternative pathway of complement activation is critical to the induction of arthritis by autoantibodies, circulating C3 was necessary and sufficient for arthritis induction.Stem Cell and Regenerative Biolog
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