A Generalization of Hierarchical Exchangeability on Trees to Directed Acyclic Graphs

Motivated by the problem of designing inference-friendly Bayesian nonparametric models in probabilistic programming languages, we introduce a general class of partially exchangeable random arrays which generalizes the notion of hierarchical exchangeability introduced in Austin and Panchenko (2014). We say that our partially exchangeable arrays are DAG-exchangeable since their partially exchangeable structure is governed by a collection of Directed Acyclic Graphs. More specifically, such a random array is indexed by $\mathbb{N}^{|V|}$ for some DAG $G=(V,E)$, and its exchangeability structure is governed by the edge set $E$. We prove a representation theorem for such arrays which generalizes the Aldous-Hoover and Austin-Panchenko representation theorems.Comment: 35 pages, 10 figures. Accepted version before re-formattin

Visual Guidance for User Placement in Avatar-Mediated Telepresence between Dissimilar Spaces

Rapid advances in technology gradually realize immersive mixed-reality (MR) telepresence between distant spaces. This paper presents a novel visual guidance system for avatar-mediated telepresence, directing users to optimal placements that facilitate the clear transfer of gaze and pointing contexts through remote avatars in dissimilar spaces, where the spatial relationship between the remote avatar and the interaction targets may differ from that of the local user. Representing the spatial relationship between the user/avatar and interaction targets with angle-based interaction features, we assign recommendation scores of sampled local placements as their maximum feature similarity with remote placements. These scores are visualized as color-coded 2D sectors to inform the users of better placements for interaction with selected targets. In addition, virtual objects of the remote space are overlapped with the local space for the user to better understand the recommendations. We examine whether the proposed score measure agrees with the actual user perception of the partner's interaction context and find a score threshold for recommendation through user experiments in virtual reality (VR). A subsequent user study in VR investigates the effectiveness and perceptual overload of different combinations of visualizations. Finally, we conduct a user study in an MR telepresence scenario to evaluate the effectiveness of our method in real-world applications

Enhancing Uptake Capability of Green Carbon Black Recycled from Scrap Tires for Water Purification

This study reports on the highly simple fabrication of green carbon black (GCB) generated from scrap tires with acetic acid to improve the adsorption efficiency for water purification, which is thoroughly compared with conventional carbon black (CB) obtained from petrochemicals. Unlike traditional modification processes with strong acids or bases, the introduction of a relatively mild acid readily allowed for the effective modification of GCB to increase the uptake capability of metal ions and toxic organic dyes to serve as effective adsorbents. The morphological features and thermal decomposition patterns were examined by electron microscopy and thermogravimetric analysis (TGA). The surface functional groups were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The structural information (ratio of D-defects/G band-graphitic domains) obtained by Raman spectroscopy clearly suggested the successful fabrication of GCB (ID/IG ratio of 0.74), which was distinctively different from typical CB (ID/IG ratio of 0.91). In the modified GCB, the specific surface area (SBET) gradually increased with the reduction of pore size as a function of acetic acid content (52.97 m2/g for CB, 86.64 m2/g for GCB, 102.10-119.50 m2/g for acid-treated GCB). The uptake capability of the modified GCB (312.5 mg/g) for metal ions and organic dyes was greater than that of the unmodified GCB (161.3 mg/g) and typical CB (181.8 mg/g), presumably due to the presence of adsorbed acid. Upon testing them as adsorbents in an aqueous solution, all these carbon materials followed the Langmuir isotherm over the Freundlich model. In addition, the removal rates of cationic species (\u3e70% removal of Cu2+ and crystal violet in 30 min) were much faster and far greater than those of anionic metanil yellow (\u3c40% removal in 3 h), given the strong electrostatic interactions. Thus, this work demonstrates the possibility of recycling waste tires in the powder form of GCB as a cost-effective and green adsorbent that can potentially substitute traditional CB, and the modification strategy provides a proof of concept for developing simple fabrication guidelines of other carbonaceous materials

The Utilization of Triton X-100 for Enhanced Two-Dimensional Liquid-Phase Proteomics

One of the main challenges in proteomics lies in obtaining a high level of reproducible fractionation of the protein samples. Automated two-dimensional liquid phase fractionation (PF2D) system manufactured by Beckman Coulter provides a process well suited for proteome studies. However, the protein recovery efficiency of such system is low when a protocol recommended by the manufacturer is used for metaproteome profiling of environmental sample. In search of an alternative method that can overcome existing limitations, this study replaced manufacturer's buffers with Triton X-100 during the PF2D evaluation of Escherichia coli K12. Three different Triton X-100 concentrations—0.1%, 0.15%, and 0.2%—were used for the first-dimension protein profiling. As the first-dimension result was at its best in the presence of 0.15% Triton X-100, second-dimension protein fractionation was performed using 0.15% Triton X-100 and the standard buffers. When 0.15% Triton X-100 was used, protein recovery increased as much as tenfold. The elution reliability of 0.15% Triton X-100 determined with ribonuclease A, insulin, α-lactalbumin, trypsin inhibitor, and cholecystokinin (CCK) affirmed Triton X-100 at 15% can outperform the standard buffers without having adverse effects on samples. This novel use of 0.15% Triton X-100 for PF2D can lead to greater research possibilities in the field of proteomics

Measuring Anxiety in Patients With Early-Stage Parkinson's Disease: Rasch Analysis of the State-Trait Anxiety Inventory

The State-Trait Anxiety Inventory (STAI), composed of two 20-item subscales (STAI-state and STAI-trait), has been increasingly used to assess anxiety symptoms in patients with Parkinson's disease (PD). However, the clinimetric attributes of the STAI under the statistical framework of the item-response theory (IRT) have not been fully elucidated within this population to date. We performed an IRT-based Rasch analysis of the STAI outcomes of patients with de novo PD from the Parkinson's Progression Markers Initiative database. The unidimensionality, Rasch model fit, scale targeting, separation reliability, differential item functioning, and response category utility of the STAI were statistically evaluated. A total of 326 (209 males, 117 females) patients without cognitive dysfunction were enrolled in our study. The original versions of the STAI-state and STAI-trait had acceptable separation reliability but lacked appropriate response category functioning, exhibited scale off-targeting, and several items demonstrated poor fit to the Rasch model. The response categories were reduced from four to three, and the rescored three-point TASI-trait demonstrated a marked improvement in clinimetric properties without a significant impact on unidimensionality and separation reliability. The rescored three-point version of the STAI-state required the additional removal of four misfitting items in order to improve the Rasch model fit. To our knowledge, this is the first study to assess the measurement properties based on the IRT of the STAI in patients with PD. Our Rasch analysis identified the components requiring possible amendments in order to improve the clinimetric attributes of the STAI

Surface-modified vacuole-based daunorubicin delivery system for acute myeloid leukaemia (AML) and their selective therapeutics

The vacuoles in Saccharomyces cerevisiae are the key players digesting the waste within the cell. This functional organelle corresponding to the lysosome of mammalians contains acidic hydrolases and specific membrane proteins. Vacuoles have more than 60 hydrolytic enzymes and can easily be modified by genetic engineering. In previous study, we optimised the encapsulation condition with appropriate time and concentration and confirmed the use of vacuole as drug delivery carrier for acute myeloid leukaemia treatment. In this study, recombinant vacuole that could target the acute myeloid leukaemia cell line was constructed. The vacuoles derived from genetic engineered yeast were decorated with targeting peptide that has specific affinity with TLR2 on AML cell membrane. The anti-cancer efficacy of AML targeting vacuoles carriers with encapsulated daunorubicin was shown to be higher than normal vacuole carriers and the crude daunorubicin. The results confirmed that target selective chemotherapy using the vacuole drug delivery system is effective and offers potential for cancer therapy