300 research outputs found

    Interface Design of Web-based Educational Platforms for Young Students

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    With the outbreak of the Covid-19 pandemic, almost all the school programs in the United States are closed. Most of the educational programs moved online. Both teachers and students have been facing great challenges adapting to this new teaching and learning mode. This paper will focus on the aesthetic design of web-based educational platforms for students and teachers from elementary school and middle school. Students from elementary school and middle school usually age from 5 to 13 years old. Their computer literacy level is still preliminary. So traditional online teaching platforms are not a good fit for them. In the meantime, there are many educational apps designed for kids at this age. However, most apps usually only provide contents for them to watch or interact with fingers, without a real teacher real-time online to teach them. Real-time online teaching started to grow commercially in the past few years, but not so much in traditional public schools. Meeting tools like Zoom, Google Meet are great applications for college students or high school students with better computer literacy. For the younger students, web designers need to give more thoughts. This paper will propose aesthetic design guidelines for educational platforms specifically for younger students and their teachers. In order to provide the best learning experience for younger students and best teaching experience for their teachers, we will first investigate users’ characteristics by surveying young students in different age groups from local public schools. The survey will focus on color preferences, thematic interests and interaction modes, etc. Teachers will be surveyed too to find out major challenges with online teaching. Apart from surveying users, we also need to study the curriculum currently in use in most elementary schools and middle schools. Based on what contents will be taught, we will find the best way to deliver to students. Existing developmental psychological theories will provide guidelines for young students’ preferences in aesthetics. Current popular applications and platforms will be compared to find out what we can improve. And we also realize that this pandemic is temporary, we positively believe this will be over soon and students will resume school physically in the fall semester. Designing web-based educational platforms will not become irrelevant until then. Most school classrooms here in the United States have smartboards, and students can even get iPad or other tablets from school. Multi-media educational applications have been in use for years. We want to provide aesthetic guidelines for educational platforms not only for online teaching but also for students in classroom

    Sunrise Seminar II. Live Streaming Piracy

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    Prevalence studies of dementia in mainland china, Hong Kong and taiwan: a systematic review and meta-analysis.

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    BACKGROUND: Many studies have considered the prevalence of dementia in mainland China, Hong Kong and Taiwan. However, area level estimates have not been produced. This study examines area differences across mainland China, Hong Kong and Taiwan adjusting for the effect of methodological factors with the aim of producing estimates of the numbers of people with dementia in these areas. METHOD AND FINDINGS: A search of Chinese and English databases identified 76 dementia prevalence studies based on samples drawn from mainland China, Hong Kong and Taiwan between 1980 and 2012. A pattern of significantly decreasing prevalence was observed from northern, central, southern areas of mainland China, Hong Kong and Taiwan. Area variations in dementia prevalence were not explained by differences in methodological factors (diagnostic criteria, age range, study sample size and sampling method), socioeconomic level or life expectancy between areas. The results of meta-analysis were applied to current population data to provide best estimate. Based on the DSM-IV diagnostic criteria, the total number of people aged 60 and over with dementia in mainland China, Hong Kong and Taiwan is 8.4 million (4.6%, 95% CI: 3.4, 5.8) and in northern, central and southern areas are 3.8 (5.1%, 95% CI: 4.1, 6.1), 3.2 (4.4%, 95% CI: 3.2, 5.6) and 1.2 (3.9%, 95% CI: 2.3, 5.4) million respectively. These estimates were mainly based on the studies existing in highly developed areas and potentially affected by incomplete and insufficient data. CONCLUSIONS: The findings of this review provide a robust estimate of area differences in dementia prevalence. Application of the estimated prevalence to population data reveals the number of people with dementia is expected to double every 20 years, areas in mainland China will be facing the greatest dementia challenge.This is the final version of the article. It first appeared from the Public Library of Science via http://dx.doi.org/10.1371/journal.pone.006625

    The effect of α- or β-casein addition to waxy maize starch on postprandial levels of glucose, insulin, and incretin hormones in pigs as a model for humans

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    Background:Starch is a main source of glucose and energy in the human diet. The extent to which it is digested in the gastrointestinal tract plays a major role in variations in postprandial blood glucose levels. Interactions with other biopolymers, such as dairy proteins, during processing can influence both the duration and extent of this postprandial surge.Objective:To evaluate the effect of the addition of bovine α- or β-casein to waxy maize starch on changes in postprandial blood glucose, insulin, and incretin hormones [glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1)] in 30 kg pigs used as an animal model for humans.Design:Gelatinised starch, Results:starch gelatinised with α-casein, and starch gelatinised with β-casein were orally administered to trained pigs (n = 8) at a level of 60 g of available carbohydrate. Pre- and postprandial glucose measurements were taken every 15 min for the first hour and every 30 min thereafter up to 180 min. Insulin, GIP, and GLP-1 levels were measured in plasma samples up to 90 min postprandial.Starch gelatinised with α-casein had a significantly (p < 0.05) lower peak viscosity on pasting and resulted in significantly lower glucose release at 15, 30, and 90 min postprandial compared to starch gelatinised with β-casein. During the first 45-min postprandial, the area under the glucose curve (AUC) for starch gelatinised with α-casein was significantly (p < 0.05) lower than that for starch gelatinised with β-casein. There was also a significant (p < 0.05) difference at T30 in GIP levels in response to the control compared to starch gelatinised with α- or β-casein. Significant (p < 0.05) increases in several free amino acid concentrations were observed on ingestion of either α- or β-casein gelatinised with starch at 30 and 90 min postprandial compared to starch alone. In addition, plasma levels of six individual amino acids were increased on ingestion of starch gelatinised with α-casein compared to ingestion of starch gelatinised with β-casein.Conclusion:The presence of casein fractions (α- or β-casein) in gelatinised waxy maize starch affects swelling characteristics, viscosity, and subsequent in vivo digestion as determined by glucose levels in blood postingestion

    Mechanical properties and crystallographic texture of non-oriented electrical steel processed by repetitive bending under tension

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    Improving the magnetic properties of non-oriented electrical steel (NOES) through the optimization of crystallographic texture has been an on-going research activity for decades. However, using traditional rolling and annealing procedures, the obtained final textures were usually very similar, i.e., exhibiting the {111} (γ) and 〈 (α) fibres, which were not the desired {001} texture (θ-fibre) for optimal magnetic quality. In the current work, a 1.8 wt% Si NOES was processed using a new sheet metal deformation method, i.e., repetitive bending under tension (R-BUT), also known as continuous bending under tension (C-BUT), to modify the texture of the electrical steel. The hot-rolled and annealed NOES plates were repeatedly bent and unbent when they were pulled under tension. The deformed plates were then heat treated at different temperatures for various times. Neutron diffraction and electron backscatter diffraction (EBSD) characterisation of the macro- and micro-textures proved that the R-BUT process significantly reduced the undesired {111} texture while promoting the {001} texture. The cube texture, which rarely formed after conventional rolling and annealing, was also seen in the R-BUT samples after annealing. It was shown that, the shear plastic deformation (induced by R-BUT) played a significant role in promoting the desired textures. In addition, the results indicated that the NOES processed by R-BUT could be deformed beyond its common formability limit, which may provide a method to address the poor workability challenge of high silicon electrical steels

    The catalytic subunit of the system L1 amino acid transporter (S<i>lc7a5</i>) facilitates nutrient signalling in mouse skeletal muscle

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    The System L1-type amino acid transporter mediates transport of large neutral amino acids (LNAA) in many mammalian cell-types. LNAA such as leucine are required for full activation of the mTOR-S6K signalling pathway promoting protein synthesis and cell growth. The SLC7A5 (LAT1) catalytic subunit of high-affinity System L1 functions as a glycoprotein-associated heterodimer with the multifunctional protein SLC3A2 (CD98). We generated a floxed Slc7a5 mouse strain which, when crossed with mice expressing Cre driven by a global promoter, produced Slc7a5 heterozygous knockout (Slc7a5+/-) animals with no overt phenotype, although homozygous global knockout of Slc7a5 was embryonically lethal. Muscle-specific (MCK Cre-mediated) Slc7a5 knockout (MS-Slc7a5-KO) mice were used to study the role of intracellular LNAA delivery by the SLC7A5 transporter for mTOR-S6K pathway activation in skeletal muscle. Activation of muscle mTOR-S6K (Thr389 phosphorylation) in vivo by intraperitoneal leucine injection was blunted in homozygous MS-Slc7a5-KO mice relative to wild-type animals. Dietary intake and growth rate were similar for MS-Slc7a5-KO mice and wild-type littermates fed for 10 weeks (to age 120 days) with diets containing 10%, 20% or 30% of protein. In MS-Slc7a5-KO mice, Leu and Ile concentrations in gastrocnemius muscle were reduced by ∼40% as dietary protein content was reduced from 30 to 10%. These changes were associated with >50% decrease in S6K Thr389 phosphorylation in muscles from MS-Slc7a5-KO mice, indicating reduced mTOR-S6K pathway activation, despite no significant differences in lean tissue mass between groups on the same diet. MS-Slc7a5-KO mice on 30% protein diet exhibited mild insulin resistance (e.g. reduced glucose clearance, larger gonadal adipose depots) relative to control animals. Thus, SLC7A5 modulates LNAA-dependent muscle mTOR-S6K signalling in mice, although it appears non-essential (or is sufficiently compensated by e.g. SLC7A8 (LAT2)) for maintenance of normal muscle mass

    Honey bee foraging distance depends on month and forage type

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    To investigate the distances at which honey bee foragers collect nectar and pollen, we analysed 5,484 decoded waggle dances made to natural forage sites to determine monthly foraging distance for each forage type. Firstly, we found significantly fewer overall dances made for pollen (16.8 %) than for non-pollen, presumably nectar (83.2 %; P < 2.2 × 10−23). When we analysed distance against month and forage type, there was a significant interaction between the two factors, which demonstrates that in some months, one forage type is collected at farther distances, but this would reverse in other months. Overall, these data suggest that distance, as a proxy for forage availability, is not significantly and consistently driven by need for one type of forage over the other

    Circulating Angiogenic Factors Associated with Response and Survival in Patients with Acute Graft-versus-Host Disease: Results from Blood and Marrow Transplant Clinical Trials Network 0302 and 0802

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    AbstractCirculating angiogenic factors (AF) reflect tissue healing capacity, although some AF can also contribute to inflammation and are indicative of endothelial dysfunction. The AF milieu in acute graft-versus-host disease (aGVHD) has not been broadly characterized. We hypothesized that patients with abundant AF involved in repair/regeneration versus those mediating damage/inflammation would have improved outcomes. Circulating AF known predominantly for repair/regeneration (epidermal growth factor [EGF], fibroblast growth factor-1 and -2, heparin binding–EGF–like growth factor, and vascular endothelial growth factor-A [VEGF-A], -C, and -D) and for damage/inflammation (angiopoietin-2, endothelin-1, soluble endoglin [sEng], follistatin [FS], leptin, and placental growth factor [PlGF]) were measured in a discovery set of hematopoietic cell recipients with grade III and IV aGVHD and compared with controls, then validated in 2 aGVHD cohorts enrolled in Blood and Marrow Transplant Clinical Trials Network (BMT CTN) trials 0302 (n = 105, serum) and 0802 (n = 158, plasma) versus controls without aGVHD (n = 53, serum). Levels of EGF and VEGF-A were lower than in controls at the onset of aGVHD in both trials and higher with complete response to first-line aGVHD therapy in CTN 0802. FS and PlGF were elevated in aGVHD measured in either serum or plasma. At day 28 after initial aGVHD therapy, elevated FS was an independent negative prognostic factor for survival in both cohorts (hazard ratio, 9.3 in CTN 0302; 2.8 in CTN 0802). These data suggest that circulating AF are associated with clinical outcomes after aGVHD and, thus, may contribute to both pathogenesis and recovery

    Increasing p-type dye sensitised solar cell photovoltages using polyoxometalates

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    Lindqvist polyoxometalate (POM) additives increase VOC in p-type DSSCs by up to 140%, yielding substantial efficiency gains for poorly matched dyes and redox mediators. For better dye/electrolyte combinations, these gains are typically outweighed by losses in JSC. Charge lifetime and transient IR measurements show that this is due to retardation of both recombination and electron transfer to the mediator, and a positive shift in the NiO valence band edge. The POMs also show their own, limited sensitizing effect
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