Towards a Unified Conversational Recommendation System: Multi-task Learning via Contextualized Knowledge Distillation

In Conversational Recommendation System (CRS), an agent is asked to recommend a set of items to users within natural language conversations. To address the need for both conversational capability and personalized recommendations, prior works have utilized separate recommendation and dialogue modules. However, such approach inevitably results in a discrepancy between recommendation results and generated responses. To bridge the gap, we propose a multi-task learning for a unified CRS, where a single model jointly learns both tasks via Contextualized Knowledge Distillation (ConKD). We introduce two versions of ConKD: hard gate and soft gate. The former selectively gates between two task-specific teachers, while the latter integrates knowledge from both teachers. Our gates are computed on-the-fly in a context-specific manner, facilitating flexible integration of relevant knowledge. Extensive experiments demonstrate that our single model significantly improves recommendation performance while enhancing fluency, and achieves comparable results in terms of diversity.Comment: EMNLP 2023 Main Conferenc

Serum amyloid A inhibits RANKL-induced osteoclast formation

When mouse bone marrow-derived macrophages were stimulated with serum amyloid A (SAA), which is a major acute-phase protein, there was strong inhibition of osteoclast formation induced by the receptor activator of nuclear factor kappaB ligand. SAA not only markedly blocked the expression of several osteoclast-associated genes (TNF receptor-associated factor 6 and osteoclast-associated receptor) but also strongly induced the expression of negative regulators (MafB and interferon regulatory factor 8). Moreover, SAA decreased c-fms expression on the cell surface via shedding of the c-fms extracellular domain. SAA also restrained the fusion of osteoclast precursors by blocking intracellular ATP release. This inhibitory response of SAA is not mediated by the well-known SAA receptors (formyl peptide receptor 2, Toll-like receptor 2 (TLR2) or TLR4). These findings provide insight into a novel inhibitory role of SAA in osteoclastogenesis and suggest that SAA is an important endogenous modulator that regulates bone homeostasis.open

Artificial Neural Network Model Development to Predict Theft Types in Consideration of Environmental Factors

Crime prediction research using AI has been actively conducted to predict potential crimes—generally, crime locations or time series flows. It is possible to predict these potential crimes in detail if crime characteristics, such as detailed techniques, targets, and environmental factors affecting the crime’s occurrence, are considered simultaneously. Therefore, this study aims to categorize theft by performing k-modes clustering using crime-related characteristics as variables and to propose an ANN model that predicts the derived categorizations. As the prediction of theft types allows people to estimate the features of the possibly most frequent thefts in random areas in advance, it enables the efficient deployment of police and the most appropriate tactical measures. Dongjak District was selected as the target area for analysis; thefts in the district showed four types of clusters. Environmental factors, representative elements affecting theft occurrence, were used as input data for a prediction model, while the factors affecting each cluster were derived through multiple linear regression analysis. Based on the results, input variables were selected for the ANN model training per cluster, and the model was implemented to predict theft type based on environmental factors. This study is significant for providing diversity to prediction methods using ANN

Pulse Broadening Effects on Ranging Performance of a Laser Altimeter with Return-to-Zero Pseudorandom Noise Code Modulation

A laser altimeter using code modulation techniques receives a backscattered pulse wider than the transmitted rectangular pulse when scanning a rough or sloped target surface. This leads to degrading the ranging performance in terms of signal-to-noise ratio (SNR) and detection probability. Unlike the pulsed techniques, little work has focused on the pulse broadening effect of the code modulation techniques. In this study, mathematical models were derived to investigate the pulse broadening effect on the ranging performance of a return-to-zero pseudorandom noise (RZPN) laser altimeter. Considering that the impulse response can be approximated by a Gaussian function, the analytical waveform was derived using a new flat-topped multi-Gaussian beam (FMGB) model. The closed-form expressions were also analytically derived for a peak cross-correlation, SNR, and detection probability in terms of the pulse broadening effect. With the use of a three-dimensional model of asteroid Itokawa for practical surface profiles, the analytical expressions were validated by comparing to the results obtained from numerical simulations. It was also demonstrated that the pulse broadening effect dropped down the peak cross-correlation and then deteriorated the ranging performance. These analytical expressions will play an important role in not only designing a laser altimeter using the RZPN code modulation technique but also analyzing its ranging performance

Broad-Temperature-Range Mechanically Tunable Hydrogel Microcapsules with a Thin Oil Layer for Controlled Release of Actives

Here, we report PNIPAm-co-PEGDA hydrogel shelled microcapsules with a thin oil layer to achieve tunable thermo-responsive release of the encapsulated small hydrophilic actives. We use a microfluidic device integrated with a temperature-controlled chamber for consistent and reliable production of the microcapsules by utilizing triple emulsion drops (W/O/W/O) with a thin oil layer as capsule templates. The interstitial oil layer between the aqueous core and the PNIPAm-co-PEGDA shell provides a diffusion barrier for the encapsulated active until the temperature reaches a critical point above which the destabilization of interstitial oil layer occurs. We find that the destabilization of the oil layer with temperature increase is caused by outward expansion of the aqueous core due to volume increase and the radial inward compression from the deswelling of the thermo-responsive hydrogel shell. The copolymerization of NIPAm with PEGDA increases the biocompatibility of the resulting microcapsule while offering the ability to alter the compressive modulus in broad ranges by simply varying crosslinker concentrations thereby to precisely tune the onset release temperature. Based on this concept, we further demonstrate that the release temperature can be enhanced up to 62 °C by adjusting the shell thickness even without varying the chemical composition of the hydrogel shell. Moreover, we incorporate gold nanorods within the hydrogel shell to spatiotemporally regulate the active release from the microcapsules by illuminating with non-invasive near infrared (NIR) light. © 2023 Elsevier B.V.11Nsciescopu

Oral delivery of stem-cell-loaded hydrogel microcapsules restores gut inflammation and microbiota

Mesenchymal stem cells (MSCs) are an attractive candidate for the treatment of inflammatory bowel disease (IBD), but their poor delivery rate to an inflamed colon is a major factor hampering the clinical potential of stem cell therapies. Moreover, there remains a formidable hurdle to overcome with regard to survival and homing in to injured sites. Here, we develop a strategy utilizing monodisperse hydrogel microcapsules with a thin intermediate oil layer prepared by a triple-emulsion drop-based microfluidic approach as an in-situ oral delivering carrier. The oral delivery of stem-cell-loaded hydrogel microcapsules (SC-HM) enhances MSC survival and retention in the hostile stomach environment due to the intermediate oil layer and low value of the overall stiffness, facilitating programmable cell release during gastrointestinal peristalsis. SC-HM is shown to induce tissue repair, reduce the colonic macrophage infiltration responsible for the secretion of the pro-inflammatory factors, and significantly mitigate the severity of IBD in a mouse model, where MSCs released by SC-HM successfully accumulate at the colonic crypt. Moreover, a metagenomics analysis reveals that SC-HM ameliorates the dysbiosis of specific bacterial genera, including Bacteroides acidifaciens, Lactobacillus (L.) gasseri, Lactobacillus reuteri, and L. intestinalis, implying optimization of the microorganism's composition and abundance. These findings demonstrate that SC-HM is a potential IBD treatment candidate. © 202211Nsciescopu

Controlled growth of perovskite layers with volatile alkylammonium chlorides

Controlling the crystallinity and surface morphology of perovskite layers by methods such as solvent engineering(1,2) and methylammonium chloride addition(3-7) is an effective strategy for achieving high-efficiency perovskite solar cells. In particular, it is essential to deposit a-formamidinium lead iodide (FAPbI(3)) perovskite thin films with few defects due to their excellent crystallinity and large grain size. Here we report the controlled crystallization of perovskite thin films with the combination of alkylammonium chlorides (RACl) added to FAPbI(3). The d-phase to a-phase transition of FAPbI(3) and the crystallization process and surface morphology of the perovskite thin films coated with RACl under various conditions were investigated through in situ grazing-incidence wide-angle X-ray diffraction and scanning electron microscopy. RACl added to the precursor solution was believed to be easily volatilized during coating and annealing owing to dissociation into RA(0) and HCl with deprotonation of RA(+) induced by RAMIDLINE HORIZONTAL ELLIPSISH+-Cl- binding to PbI2 in FAPbI(3). Thus, the type and amount of RACl determined the d-phase to a-phase transition rate, crystallinity, preferred orientation and surface morphology of the final a-FAPbI(3). The resulting perovskite thin layers facilitated the fabrication of perovskite solar cells with a power-conversion efficiency of 26.08% (certified 25.73%) under standard illumination

Stretchable and Biocompatible Transparent Electrodes for Multimodal Biosignal Sensing from Exposed Skin

Abstract Real‐time health monitoring technology in daily life requires mechanically robust and transparent electrodes for multimodal biosignal sensing from exposed human epidermis. Here, highly stretchable transparent electrodes comprising a water‐dispersed conductive polymer, poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS), and a protic ionic liquid (IL), 3‐methylimidazolium:bis(trifluoromethylsulfonyl)amide (p‐MIM:TFSI) are reported. Owing to the high water miscibility of p‐MIM:TFSI and its favorable ion exchange capability with PEDOT:PSS, PEDOT:PSS/p‐MIM:TFSI transparent electrodes show enhanced electrical conductivity (σ = 450 S cm−1) and thin‐film stretchability represented by crack onset strain (εc) exceeding 50%. These electrodes outperform other PEDOT:PSS electrodes processed with an aprotic counterpart, 1‐ethyl‐3‐methylimidazolium(EMIM):TFSI, or a traditional ionic salt, Li:TFSI. The PEDOT:PSS/p‐MIM:TFSI thin‐film electrodes are also biocompatible and conformally adhere to human skin; therefore, multimodal biosignals including electrocardiogram, electrooculogram, and electromyogram with high signal‐to‐noise ratios from exposed epidermis on human faces and arms under various measurement conditions mimicking daily activities are collected. Considering the importance of light penetration through human skin for stable biological activity during biosignal monitoring, the results can broaden the applicability of daily‐use wearable biosignal sensors by applying them to exposed human skin