1,458 research outputs found
Diffusion Model-Augmented Behavioral Cloning
Imitation learning addresses the challenge of learning by observing an
expert's demonstrations without access to reward signals from environments.
Most existing imitation learning methods that do not require interacting with
environments either model the expert distribution as the conditional
probability p(a|s) (e.g., behavioral cloning, BC) or the joint probability p(s,
a) (e.g., implicit behavioral cloning). Despite its simplicity, modeling the
conditional probability with BC usually struggles with generalization. While
modeling the joint probability can lead to improved generalization performance,
the inference procedure can be time-consuming and it often suffers from
manifold overfitting. This work proposes an imitation learning framework that
benefits from modeling both the conditional and joint probability of the expert
distribution. Our proposed diffusion model-augmented behavioral cloning (DBC)
employs a diffusion model trained to model expert behaviors and learns a policy
to optimize both the BC loss (conditional) and our proposed diffusion model
loss (joint). DBC outperforms baselines in various continuous control tasks in
navigation, robot arm manipulation, dexterous manipulation, and locomotion. We
design additional experiments to verify the limitations of modeling either the
conditional probability or the joint probability of the expert distribution as
well as compare different generative models
Exposure to sexually explicit media in early adolescence is related to risky sexual behavior in emerging adulthood
[[abstract]]BACKGROUND:
Sexually explicit media exposure during early adolescence has been found to be associated with risky sexual behavior. However, previous study suffered from methodological issue, such as selection bias. Furthermore, little is known about the effect of multi-modality sexually explicit media exposure on risky sexual behavior, and how this relationship can be applied to non-western societies.
OBJECTIVES:
This study aimed to improve upon previous studies by using instrumental variable estimation. In addition, this study also included multi-modality of sexually explicit media and three risky sexual behavior measure from a sample of Taiwanese adolescents.
METHODS:
Participants were recruited from a prospective longitudinal study (Taiwan Youth Project). All were in 7th grade (mean age = 13.3) when the study was initiated in 2000. Sexually explicit media exposure, including ever-exposure and number of modalities exposed to, was measured in wave 2 (8th grade). Risky sexual behavior was measured in waves 8 (mean age = 20.3) and 10 (mean age = 24.3). A two-stage least squares regression was employed, with pubertal timing as the instrumental variable.
RESULTS:
About 50% of participants had been exposed to sexual media content by 8th grade, from an average of one modality. Sexually explicit media exposure predicted early sexual debut, unsafe sex, and multiple sexual partners (all: p < .05). Furthermore, exposure to more media modalities increased the likelihood of risky sexual behaviors. However, only the effect on early sexual debut was gender invariant.
CONCLUSIONS:
Exposure to sexually explicit media in early adolescence had a substantive relationship with risky sexual behavior in the emerging adulthood. Knowledge of this causal like effect provides a basis for building better preventive programs in early adolescence. One prominent way is early education on media literacy, and physicians themselves may need to be familiar with such content to initiate it.[[notice]]補正完
Differential cellular responses to FDA-approved nanomedicines:an exploration of albumin-based nanocarriers and liposomes in protein corona formation
Tetrabutylammonium bis[4,4′-dimethyl-2,2′-(3,7-dimethyl-1H-4,2,1-benzothiazasiline-1,1-diyl)dibenzenethiolato]vanadium(III) acetonitrile tetrasolvate
In the title compound, [N(C4H9)4][V(C23H21NS3Si)2]·4CH3CN, the VIII atom (site symmetry ) is coordinated by two N,S,S′-tridentate 4,4′-dimethyl-2,2′-(3,7-dimethyl-1H-4,2,1-benzothiazasiline-1,1-diyl)dibenzenethiolate ligands in a distorted trans-VN2S4 octahedral geometry. The complete cation is generated by crystallographic twofold symmetry, with the V atom lying on the rotation axis. The unusual ligand arose from nucleophilic attack on the coordinated nitrile by the thiolate precursor and reduction of nitrile to the imidate
Oxygen Vacancy Induced Ferromagnetism in VO
{\it Ab initio} calculations within density functional theory with
generalized gradient approximation have been performed to study the effects of
oxygen vacancies on the electronic structure and magnetism in undoped
VO (). It is found that the introduction of oxygen
vacancies would induce ferromagnetism in VO with the magnetization
being proportional to the O vacancy concentration . The calculated
electronic structure reveals that the valence electrons released by the
introduction of oxygen vacancies would occupy mainly the neighboring V
-dominant band which then becomes spin-polarized due to intra-atomic
exchange interaction, thereby giving rise to the half-metallic ferromagnetism.Comment: To be published as a Letter in J. Phys. Soc. Japa
UMARS: Un-MAppable Reads Solution
[[abstract]]Background: Un-MAppable Reads Solution (UMARS) is a user-friendly web service focusing on retrieving valuable information from sequence reads that cannot be mapped back to reference genomes. Recently, next-generation sequencing (NGS) technology has emerged as a powerful tool for generating high-throughput sequencing data and has been applied to many kinds of biological research. In a typical analysis, adaptor-trimmed NGS reads were first mapped back to reference sequences, including genomes or transcripts. However, a fraction of NGS reads failed to be mapped back to the reference sequences. Such un-mappable reads are usually imputed to sequencing errors and discarded without further consideration.Methods: We are investigating possible biological relevance and possible sources of un-mappable reads. Therefore, we developed UMARS to scan for virus genomic fragments or exon-exon junctions of novel alternative splicing isoforms from un-mappable reads. For mapping un-mappable reads, we first collected viral genomes and sequences of exon-exon junctions. Then, we constructed UMARS pipeline as an automatic alignment interface.Results: By demonstrating the results of two UMARS alignment cases, we show the applicability of UMARS. We first showed that the expected EBV genomic fragments can be detected by UMARS. Second, we also detected exon-exon junctions from un-mappable reads. Further experimental validation also ensured the authenticity of the UMARS pipeline. The UMARS service is freely available to the academic community and can be accessed via http://musk.ibms.sinica.edu.tw/UMARS/.Conclusions: In this study, we have shown that some un-mappable reads are not caused by sequencing errors. They can originate from viral infection or transcript splicing. Our UMARS pipeline provides another way to examine and recycle the un-mappable reads that are commonly discarded as garbage
Temporomandibular Joint Disorders in Patients with Rheumatoid Arthritis
BackgroundTemporomandibular joint disorders (TMD) are not uncommon in patients with rheumatoid arthritis (RA). However, the extent of involvement and its clinical relevance have not been well characterized. This study evaluated the correlation between the severity of RA-related TMD and RA, as well as determined the potential predictors for early identification and management of TMD in RA patients.MethodsWe sequentially recruited 56 adult RA patients from our Arthritis Clinic. TMD and RA were surveyed, clinically by questionnaires and physical examinations, and radiologically by tomography in TMD and conventional radiography in RA. The patients were stratified into no, mild and severe TMD groups according to the physical and tomographic examinations. The correlation of the severity of TMD and RA were evaluated. The relative importance of relevant predictors of severe TMD was analyzed by a logistic regression model.ResultsPhysical and radiologic temporomandibular joint abnormalities were found to be highly prevalent (85.7% and 74.5%) in these patients, and the occurrence increased to as much as 92.9% when the 2 data sets were combined. More than half of the patients had severe TMD presenting with debilitating symptoms or with a significant degree of bony destruction. The severity of TMD was variably correlated with RA severity. The score of hand-joint space narrowing was found to be the most influential predictor of severe TMD by logistic regression analysis.ConclusionThere was a high prevalence of TMD in RA patients. The severity of TMD variably correlated with RA severity. Clinically, a high score of hand-joint space narrowing may serve as an early indicator of RA patients at risk of severe TMD. This may facilitate early management and prevent the functional impairment of the temporomandibular joint
Epigallocatechin-3-gallate-mediated cardioprotection by Akt/GSK-3β/caveolin signalling in H9c2 rat cardiomyoblasts
Background: Epigallocatechin-3-gallate (EGCg) with its potent anti-oxidative capabilities is known for its beneficialeffects ameliorating oxidative injury to cardiac cells. Although studies have provided convincing evidence tosupport the cardioprotective effects of EGCg, it remains unclear whether EGCg affect trans-membrane signalling incardiac cells. Here, we have demonstrated the potential mechanism for cardioprotection of EGCg againstH2O2-induced oxidative stress in H9c2 cardiomyoblasts.Results: Exposing H9c2 cells to H2O2 suppressed cell viability and altered the expression of adherens and gapjunction proteins with increased levels of intracellular reactive oxygen species and cytosolic Ca2+. These detrimentaleffects were attenuated by pre-treating cells with EGCg for 30 min. EGCg also attenuated H2O2-mediated cell cyclearrest at the G1-S phase through the glycogen synthase kinase-3β (GSK-3β)/β-catenin/cyclin D1 signalling pathway.To determine how EGCg targets H9c2 cells, enhanced green fluorescence protein (EGFP) was ectopically expressedin these cells. EGFP-emission fluorescence spectroscopy revealed that EGCg induced dose-dependent fluorescencechanges in EGFP expressing cells, suggesting that EGCg signalling events might trigger proximity changes of EGFPexpressed in these cells.Proteomics studies showed that EGFP formed complexes with the 67 kD laminin receptor, caveolin-1 and -3,β-actin, myosin 9, vimentin in EGFP expressing cells. Using in vitro oxidative stress and in vivo myocardial ischemiamodels, we also demonstrated the involvement of caveolin in EGCg-mediated cardioprotection. In addition,EGCg-mediated caveolin-1 activation was found to be modulated by Akt/GSK-3β signalling in H2O2-induced H9c2cell injury.Conclusions: Our data suggest that caveolin serves as a membrane raft that may help mediate cardioprotectiveEGCg transmembrane signalling
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