Identification of the prebiotic translation apparatus within the contemporary ribosome

A structural element that could have existed independently in the prebiotic era was identified at the active site of the contemporary ribosome. It is suggested to have functioned as a proto-ribosome catalyzing peptide bond formation and non-coded elongation in the same manner that contemporary ribosomes exert positional catalysis, namely by accommodating the reactants in stereochemistry favourable for inline nucleophilic attack. This simple apparatus is a dimer of self-folding RNA units that could have assembled spontaneously into a symmetrical pocket-like structure, sufficiently efficient to be preserved throughout evolution as the active site of modern ribosomes, thus presenting a conceivable starting point for translation.Here we discuss the proto-ribosome emergence hypothesis and show that the tendency for dimerization, a prerequisite for obtaining the catalytic centre, is linked to the fold of its two components, indicating functional selection at the molecular level in the prebiotic era and supporting the existence of dimeric proto-ribosome

A Case Study on Designing Evaluations of ML Explanations with Simulated User Studies

When conducting user studies to ascertain the usefulness of model explanations in aiding human decision-making, it is important to use real-world use cases, data, and users. However, this process can be resource-intensive, allowing only a limited number of explanation methods to be evaluated. Simulated user evaluations (SimEvals), which use machine learning models as a proxy for human users, have been proposed as an intermediate step to select promising explanation methods. In this work, we conduct the first SimEvals on a real-world use case to evaluate whether explanations can better support ML-assisted decision-making in e-commerce fraud detection. We study whether SimEvals can corroborate findings from a user study conducted in this fraud detection context. In particular, we find that SimEvals suggest that all considered explainers are equally performant, and none beat a baseline without explanations -- this matches the conclusions of the original user study. Such correspondences between our results and the original user study provide initial evidence in favor of using SimEvals before running user studies. We also explore the use of SimEvals as a cheap proxy to explore an alternative user study set-up. We hope that this work motivates further study of when and how SimEvals should be used to aid in the design of real-world evaluations.Comment: 9 pages, 2 figure

Developing an Older Adult Volunteer Program in a New York Chinese Community: An Evidence-Based Approach

This study reports the results of a pilot volunteer project for older Chinese immigrants and documents benefits for both volunteers and caregiver recipients. Using a social marketing approach, the volunteer project was designed as a social model to promote better health among older Chinese immigrants in New York City. The packaging of this health promotion project as a volunteer program was based on a strengths perspective. In the program, 18 older Chinese immigrants were trained to provide support and referral to family caregivers of ill relatives in the Chinese community. At 6 months, outcomes were evaluated for both volunteers and caregivers. The older volunteers perceived benefits associated with volunteering, specifically, a greater sense of well-being and satisfaction with life. In addition, the majority of volunteers felt empowered by training and volunteering (100 %), felt the skills they learned improved communication with their own families (90 %), and reported physical and emotional health benefits (61 %). At the same time, caregivers reported stress reduction following volunteer support. Findings suggest that a volunteer program model may be an effective health promotion intervention for older Chinese immigrants

Profiling Interactive Television Research: A Bibliometric Review

Though the recent revolution in digital processing ushers the broadcasting industry into a new era, the interactive television (iTV) has been regarded as the third generation of broadcasting services and relevant issues of iTV have gained tremendous interests from both academics and practitioners. This article endeavours to profile the scholarly development of the interactive television literatures by utilizing bibliometric technique to review the literature material in SCIE, SSCI, and A&HCI databases appeared in 1970 to 2009. There are 228 documents in total. The analysis is conducted on such as most productive authors, authors’ background, geographic diversity analysis (including countries and institutions), subject areas, publication year, and the citation analysis. The conclusions about the promising future, research direction, and the attribute of interactive television research are derived from this study

The opportunity recognition framework in the Hong Kong SMEs context

This paper presents a preliminary framework of opportunity recognition in the Hong Kong small and medium enterprises (SMEs) context. Guanxi and four trait variables, namely self-monitoring, extroversion, selfefficacy and creativity are the independent variables while the number of opportunity recognized by entrepreneurs is the dependent variable in the framework. The model indicates a mediation effect of guanxi between self-monitoring and the number of opportunities recognized, and between extroversion and the number of opportunities recognized. Meanwhile, SMEs marketing characteristics are determined by personalities and behaviour of the entrepreneurs as they do not conform to the traditional marketing theories (Gilmore et al., 2001). This paper provides new research directions to the field of SMEs marketing

Impregnation of Materials in Supercritical CO₂ to Impart Various Functionalities

Supercritical CO2 (scCO2) impregnation has attracted growing interest due to its unique properties such as high diffusivity, low surface tension, and ease of solvent removal at the end of the process. In addition, scCO2 is the most environmentally acceptable solvent possessing many advantages compared with the conventional aqueous and solvent-based processing. scCO2 impregnation has a wide range of applications mainly used to incorporate various active principles such as pharmaceuticals, functional finishing agents, colorants, and other agents into a polymeric matrix. This chapter reviews some studies carried out so far about the application of scCO2 as impregnation medium to develop various functional materials and it is intended to stimulate further research into the application of scCO2 to textile functionalization. It mainly focuses on applications related to textiles and some polymeric films

COVID-19 transmission within a family cluster by presymptomatic carriers in China

We report a COVID-19 family cluster caused by a presymptomatic case. There were 9 family members, including 8 laboratory-confirmed with COVID-19, and a 6-year-old child had no evidence of infection. Amongst the 8 patients, one adult and one 13-month-old infant were asymptomatic, one adult was diagnosed as having severe pneumonia

Solubility of Chitin: Solvents, Solution Behaviors and Their Related Mechanisms

Chitin is a natural polysaccharides having a unique molecular arrangement of 2-(acetylamino)-2-deoxy-d-glucose, it possesses multifunctional properties and is suitable for various applications mainly in pharmaceutical, biomedical food, textiles and packaging fields. Therefore, being considered as a superior material for a sustainable future of industrial development, chitin perfectly meets up the demands with diversified functionalities in applications, excellent biocompatibility and biodegradability. Non-toxicity to human and environment (air, water and soil) is a great opportunity for this revolutionary, innovative and sustainable material. Moreover, antibacterial potency and low immunogenicity of chitin have broadened the aspects of research and development on structure-function relationship toward biological tissues and activities. Despite abundance, low cost and availability, many experimental data from potential studies, reproducibility problems of chitin solubility measurement still limit the development of products and access to the market in large volume. Batch-to-batch variability, non-precise characterization and randomly distributed acetyl groups of chitin structure eventually results in a bad reproducibility of chitin solubility. Therefore, the chapter aims to organize the information of chitin structure at molecular level and correlate solubility with chitin structure. Moreover, the dissolution mechanism and solution behaviors in different solvents will be discussed in this chapter

Metal: A Metadata-Hiding File-Sharing System

File-sharing systems like Dropbox offer insufficient privacy because a compromised server can see the file contents in the clear. Although encryption can hide such contents from the servers, metadata leakage remains significant. The goal of our work is to develop a file-sharing system that hides metadata---including user identities and file access patterns. Metal is the first file-sharing system that hides such metadata from malicious users and that has a latency of only a few seconds. The core of Metal consists of a new two-server multi-user oblivious RAM (ORAM) scheme, which is secure against malicious users, a metadata-hiding access control protocol, and a capability sharing protocol. Compared with the state-of-the-art malicious-user file-sharing scheme PIR-MCORAM (Maffei et al.\u2717), which does not hide user identities, Metal hides the user identities and is 500x faster (in terms of amortized latency) or 10^5x faster (in terms of worst-case latency)

Far-Infrared Emission Properties and Thermogravimetric Analysis of Ceramic-Embedded Polyurethane Films

The far-infrared ray (FIR) is one kind of electromagnetic wave employed for numerous bio-interactive applications such as body thermoregulation, infrared therapy, etc. Tuning the FIR-emitting property of the functional textile surface can initiate a new horizon to utilize this property in sportswear or even smart textiles. Ceramic particles were studied for their unique ability to constantly emit FIR rays. The purpose of this research is to characterize the FIR emis-sion properties and the thermogravimetric analysis of ceramic-embedded polyurethane films. For this purpose, ceramic particles such as aluminum oxide, silicon dioxide, and titanium diox-ide were incorporated (individually) with water-based polyurethane (WPU) binder by a soni-cation technique to make a thin layer of film. Significant improvement in FIR emissive property of the films was found when using different ceramic particles into the polyurethane films. Re-flection and transmission at the FIR range were measured with a gold integrating sphere by Fourier-transform infrared (FTIR) spectrometer. The samples were also characterized by ther-mogravimetric analysis (TGA). Different physical tests, such as tensile strength and contact angle measurements, were performed to illustrate the mechanical properties of the films. The study suggested that the mechanical properties of the polyurethane films were significantly influenced by the addition of ceramic particles