93 research outputs found
Analyzing EFL learners’ demotivating factors in blended learning context
In second language and foreign language learning, demotivation in learning is a common occurrence. Almost all previous studies on learners’ demotivation focused on traditional classroom learning environment rather than blended learning setting. This paper investigates learner perceptions of demotivating factors for Chinese EFL college students in blended learning context. 272 college sophomores with varied majors from a university in Mid-East China took part in a questionnaire survey. The questionnaire, consisted of 34 4-point Likert type items about learners’ demotivation in a blended EFL learning environment, was adapted from Kikuchi’s demotivation questionnaire and Xie’s LPDS (Learner Perceptions of Demotivator Scale). An exploratory factor analysis was performed to explore the factor structure of the questionnaire items. Then mean scores of items loading on each factor were calculated and independent samples t-test analysis was adopted to examine the differences of demotivating factors between different groups of participants. Five demotivating factors from the questionnaire were extracted. The findings reveal a newly discovered factor: learners’ lack of self-discipline in online learning. The paper indicates that there is no significant difference of these five demotivating factors between male and female learners, and between rural and urban learners. Whereas less motivated learners perceive four among the five factors to be more demotivating than more motivated learners
Mechanisms of Cell Cycle Control Revealed by a Systematic and Quantitative Overexpression Screen in S. cerevisiae
Regulation of cell cycle progression is fundamental to cell health and reproduction, and failures in this process are associated with many human diseases. Much of our knowledge of cell cycle regulators derives from loss-of-function studies. To reveal new cell cycle regulatory genes that are difficult to identify in loss-of-function studies, we performed a near-genome-wide flow cytometry assay of yeast gene overexpression-induced cell cycle delay phenotypes. We identified 108 genes whose overexpression significantly delayed the progression of the yeast cell cycle at a specific stage. Many of the genes are newly implicated in cell cycle progression, for example SKO1, RFA1, and YPR015C. The overexpression of RFA1 or YPR015C delayed the cell cycle at G2/M phases by disrupting spindle attachment to chromosomes and activating the DNA damage checkpoint, respectively. In contrast, overexpression of the transcription factor SKO1 arrests cells at G1 phase by activating the pheromone response pathway, revealing new cross-talk between osmotic sensing and mating. More generally, 92%–94% of the genes exhibit distinct phenotypes when overexpressed as compared to their corresponding deletion mutants, supporting the notion that many genes may gain functions upon overexpression. This work thus implicates new genes in cell cycle progression, complements previous screens, and lays the foundation for future experiments to define more precisely roles for these genes in cell cycle progression
Core-sheath structured electrospun nanofibrous membranes for oil-water separation
In recent years, both the increasing frequency of oil spill accidents and the urgency to deal seriously with industrial oil-polluted water, encouraged material scientists to design highly efficient, cost effective oil-water separation technologies. We report on electrospun nanofibrous membranes which are composed of core-sheath structured cellulose-acetate (CA)-polyimide (PI) nanofibers. On the surface of the CA-PI fibers a fluorinated polybenzoxazine (F-PBZ) functional layer, in which silica nanoparticles (SNPs) were incorporated, has been applied. Compared with F-PBZ/SNP modified CA fibers reported before for the separation of oil from water, the PI-core of the core-shell F-PBZ/SNP/CA-PI fibers makes the membranes much stronger, being a significant asset in their use. Nanofibrous membranes with a tensile strength higher than 200 MPa, a high water contact angle of 160 degrees and an extremely low oil contact angle of 0 degrees were obtained. F-PBZ/SNP/CA-PI membranes seemed very suitable for gravity-driven oil-water separation as fast and efficient separation (>99%) of oil from water was achieved for various oil-water mixtures. The designed core-sheath structured electrospun nanofibrous membranes may become interesting materials for the treatment of industrial oil-polluted water
An empirical study on the collaborative usability of age-appropriate smart home interface design
IntroductionThe smart home has become a popular product, but with the development of the aging population, the differentiated characteristics of the elderly smart home products in terms of demand and use are becoming more and more significant. The existing smart products are complicated to operate and cumbersome to interact with, which increases the cognitive load of the elderly group and hinders the daily use and user experience feeling of the elderly. The purpose of this paper is to study the interface data information and interface visual design starting from hardware and software, interface interaction, to explore the better interface data information and interface visual design, and to output, a new prototype of the operating interface of smart home system for the elderly, so that the smart products can be better used by the elderly.MethodsThirty-two participants aged 55–75 were invited to conduct the test, and subjective evaluation was conducted at the end of the test. Through the tests, the operability of the prototype structure for smart furniture systems for the elderly was demonstrated.ResultsIn terms of functionality a new task based on a combination of icons and text is proposed. In the control of devices, the switching status of devices, etc., needs to be clearly distinguished visually, eye-protective bright colors are used, paired with low saturation to highlight the focus, and high bright colors with gray to distinguish the device status. In terms of the density of the content, an appropriate proportion of images and text were used to make the information less dense. ln the arrangement of web content, information content relevant to users was placed first as much as possible.DiscussionBased on this, a secondary optimal design was carried out to improve the interactive design of the smart home for the elderly and output it as a prototype interactive interface. Thus, the operability, rationality, and aesthetic comfort of the prototype design of smart home interaction in an age-friendly scenario are improved, allowing the elderly to have a better experience when using the smart home
Current Status of the Chinese National Twin Registry
The Chinese National Twin Registry is the first and largest population-based twin registry in China. It was established in 2001. The primary goal of this program is the establishment of a population-based twin registry of 45,000 twin pairs from several regions representing north, south, urban, and rural areas in China. A secondary goal is to study genetic contributions to complex diseases, and to test associations of candidate genes with related phenotypes. Seven thousand, four hundred and twenty-three twin pairs have been enrolled in the registry in which 1613 pairs have undergone detailed questionnaire assessments and physical examination. Based on the baseline registry, a twin cohort was established. Continued research includes studies on intermediate phenotypes of cardiovascular and cerebrovascular diseases and psychological studies in adult twins, studies on growth and development in adolescent twins, and so forth. The current state and future plans for the Chinese National Twin Registry will be discussed in this article.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000243216600009&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Genetics & HeredityObstetrics & GynecologySCI(E)PubMed17ARTICLE6747-752
Prediction of microdialysis relative recovery of flavone derivatives based on molecular descriptors
Inonotus obliquus polysaccharide are linear molecules that alter the abundance and composition of intestinal microbiota in Sprague Dawley rats
IntroductionThe macromolecular polysaccharide Inonotus obliquus polysaccharide (IOP) is composed of various monosaccharides, and it could modulate the composition and diversity of intestinal flora. However, its impact on the intestinal flora in rats of different genders remains unclear. Therefore, this study aims to investigate the structural changes of IOP and its effects on the intestinal flora after administration in male and female rats.MethodsIn this study, the molecular weight and purity of IOP were analyzed by high-performance gel permeation chromatography (HPGPC) and phenol sulfuric acid method, and NMR was used to confirm the chemical structure of IOP. Sex hormone [testosterone (T) and estradiol (E2)] levels and intestinal microbial changes were detected by enzyme-linked immunosorbent assay (ELISA) and 16S rRNA, respectively, after gavage of IOP (100 mg/kg) in male and female Sprague Dawley (SD) rats.ResultsHPGPC analysis showed that the average molecular weight (Mw) of IOP was 4,828  Da, and the total sugar content of the purified IOP was 96.2%, indicating that the polysaccharide is of high purity. NMR revealed that IOP is a linear macromolecule with an α-D-type glucose backbone. The results of ELISA and 16S rRNA showed that the IOP increased the abundance of beneficial bacteria, such as Clostridia_UCG-014 and Prevotellaceae_NK3B31, and reduced that of harmful bacteria, such as Colidextribacter and Desulfobacterota in the intestine of both male and female rats, and IOP changed the levels of sex hormones in male and female rats. Further analyses revealed that the increase in alpha diversity was higher in male than female rats. α diversity and β diversity revealed a significant difference in the composition of cecal microbiota between male and female rats in the control group, but IOP intake reduced this difference. Meanwhile, α analysis revealed a change in the composition of bacterial flora was more stable in male than female rats.ConclusionsThis study enhances our comprehension of the IOP structure and elucidates the alterations in intestinal flora following IOP administration in rats of varying genders. Nonetheless, further investigation is warranted to explore the specific underlying reasons for these discrepancies
The Genetic Correlation Between Cigarette Smoking and Alcohol Drinking Among Chinese Adult Male Twins: An Ordinal Bivariate Genetic Analysis
Quasi-Free Electron States Responsible for Single-Molecule Conductance Enhancement in Stable Radical
Stable organic radicals, which possess half-filled orbitals in the vicinity of the Fermi energy, are promising candidates for electronic devices. In this Letter, using a combination of scanning-tunneling-microscopy-based break junction (STM-BJ) experiments and quantum transport theory, a stable fluorene-based radical is investigated. We demonstrate that the transport properties of a series of fluorene derivatives can be tuned by controlling the degree of localization of certain orbitals. More specifically, radical has a delocalized half-filled orbital resulting in Breit-Wigner resonances, leading to an unprecedented conductance enhancement of 2 orders of magnitude larger than the neutral nonradical counterpart ( ). In other words, conversion from a closed-shell fluorene derivative to the free radical in opens an electron transport path which massively enhances the conductance. This new understanding of the role of radicals in single-molecule junctions opens up a novel design strategy for single-molecule-based spintronic devices
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