17,762 research outputs found

    Fast synchrotron X-ray tomographic quantification of dendrite evolution during the solidification of Mg-Sn alloys

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    The evolution of dendritic microstructures during the solidification of a Mg-15 wt%Sn alloy was investigated in situ via fast synchrotron X-ray microtomography. To enable these in situ observations a novel encapsulation method was developed and integrated into a fast, pink beam, imaging beamline at Diamond Light Source. The dendritic growth was quantified with time using: solid volume fraction, tip velocity, interface specific surface area, and surface curvature. The influence of cooling rate upon these quantities and primary phase nucleation was investigated. The primary dendrites grew with an 18-branch, 6-fold symmetry structure, accompanied by coarsening. The coarsening process was assessed by the specific surface area and was compared with the existing models. These results provide the first quantification of dendritic growth during the solidification of Mg alloys, confirming existing analytic models and providing experimental data to inform and validate more complex numeric models

    A Case of Bowen’s Disease and Small-Cell Lung Carcinoma: Long-Term Consequences of Chronic Arsenic Exposure in Chinese Traditional Medicine

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    Chronic arsenic toxicity occurs primarily through inadvertent ingestion of contaminated water and food or occupational exposure, but it can also occur through medicinal ingestion. This case features a 53-year-old lifetime nonsmoker with chronic asthma treated for 10 years in childhood with Chinese traditional medicine containing arsenic. The patient was diagnosed with Bowen’s disease and developed extensive-stage small-cell carcinoma of the lung 10 years and 47 years, respectively, after the onset of arsenic exposure. Although it has a long history as a medicinal agent, arsenic is a carcinogen associated with many malignancies including those of skin and lung. It is more commonly associated with non–small-cell lung cancer, but the temporal association with Bowen’s disease in the absence of other chemical or occupational exposure strongly points to a causal role for arsenic in this case of small-cell lung cancer. Individuals with documented arsenic-induced Bowen’s disease should be considered for more aggressive screening for long-term complications, especially the development of subsequent malignancies

    One-Watt level mid-IR output, singly resonant, continuous-wave optical parametric oscillator pumped by a monolithic diode laser

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    We report more than 1.1 Watt of idler power at 3373 nm in a singly resonant optical parametric oscillator (SRO), directly pumped by a single-frequency monolithic tapered diode laser. The SRO is based on a periodically poled MgO:LiNbO3 crystal in a four mirror cavity and is excited by 8.05 W of 1062 nm radiation. The SRO pump power at threshold is 4 W. The internal slope-efficiency and conversion efficiency reach 89% and 44% respectively. The signal and idler waves are temperature tuned in the range of 1541 to 1600 nm and 3154 to 3415 nm respectively. To the best of our knowledge, this is the highest output obtained for a diode pumped optical parametric oscillator (OPO), and the first time a SRO is directly pumped by a monolithic tapered diode laser

    A review of metacognition: implications for teaching and learning

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    This working paper brief introduces key definitions of metacognition and presents research that shows the importance of developing student metacognition in education. It also presents classroom strategies that can promote student metacognition

    Eye movement pattern in face recognition is associated with cognitive decline in the elderly

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    Conference Theme: Mind, Technology, and SocietyThe present study investigated the relationship between eye movement pattern in face recognition and cognitive perform-ance during natural aging through modeling and comparing eye movement of young (18-24 years) and older (65-81 years) adults using Hidden Markov Model (HMM) based approach. Young adults recognized faces better than older adults, particularly when measured by the false alarm rate. Older adults’ recognition performance, on the other hand, correlated with their cognitive status assessed by the Montreal Cognitive Assessment (MoCA). Eye movement analysis with HMM revealed two different strategies, namely “analytic” and “holistic”. Participants using the analytic strategy had better recognition performance (particularly in the false alarm rate) than those using the holistic strategy. Significantly more young adults adopted the analytic strategy; whereas more older adults adopted the holistic strategy. Interestingly, older adults with lower cognitive status were associated with higher likelihood of using the holistic strategy. These results suggest an association between holistic eye movement patterns and cognitive decline in the elderly.postprin

    Analytic eye movement patterns in face recognition are associated with better performance and more top-down control of visual attention: an fMRI study

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    Conference Theme: Integrating Psychological, Philosophical, Linguistic, Computational and Neural PerspectivesPoster Session 3: no. 57Recent research has revealed two different eye movement patterns during face recognition: holistic and analytic. The present study investigated the neural correlates of these two patterns through functional magnetic resonance imaging (fMRI). A more holistic pattern was associated with more activation in the face-selective perceptual areas, including the occipital face area and fusiform face area. In contrast, participants using a more analytic pattern demonstrated more activation in areas important for top-down control of visual attention, including the frontal eye field and intraparietal sulcus. In addition, participants using the analytic patterns had better recognition performance than those showing holistic patterns. These results suggest that analytic eye movement patterns are associated with more engagement of top-down control of visual attention, which may consequently enhance recognition performance.postprin

    Incoherently pumped continuous wave optical parametric oscillator broadened by non-collinear phasematching

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    In this paper, we report on a singly resonant optical parametric oscillator (OPO) pumped by an amplified spontaneous emission (ASE) source. The pump focusing conditions allow non-collinear phasematching, which resulted in a 230 nm (190 cm−1^{-1}) spectral bandwidth. Calculations indicate that such phasematching schemes may be used to further broaden OPO spectral bandwidths.Comment: 7 pages 4 figure

    In Vitro Regeneration of Bamboo Species

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    This review paper discussed about journals related to micropropagation of bamboo species. In recent years, the application of tissue culture technique like in vitro micropropagation has been used to meet the demands for bamboo products. In the past 30 years, protocols for micropropagation of various bamboo species have been established by researchers from all over the world. The controlling factors for cultures such as the explants, culture medium, carbon sources, combination and concentration of plant growth regulators and other additional additives are varied amongst. The controlling factors are crucial in developing successful regeneration protocols for various bamboo species. This paper is attempted to review and summarize the available and up to date information regarding in vitro micropropagation of bamboos

    Health of Philippine Emigrants Study (HoPES): study design and rationale.

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    BackgroundImmigrants to the United States are usually healthier than their U.S.-born counterparts, yet the health of immigrants declines with duration of stay in the U.S. This pattern is often seen for numerous health problems such as obesity, and is usually attributed to acculturation (the adoption of "American" behaviors and norms). However, an alternative explanation is secular trends, given that rates of obesity have been rising globally. Few studies of immigrants are designed to distinguish the effects of acculturation versus secular trends, in part because most studies of immigrants are cross-sectional, lack baseline data prior to migration, and do not have a comparison group of non-migrants in the country of origin. This paper describes the Health of Philippine Emigrants Study (HoPES), a study designed to address many of these limitations.MethodsHoPES is a dual-cohort, longitudinal, transnational study. The first cohort consisted of Filipinos migrating to the United States (n = 832). The second cohort consisted of non-migrant Filipinos who planned to remain in the Philippines (n = 805). Baseline data were collected from both cohorts in 2017 in the Philippines, with follow-up data collection planned over 3 years in either the U.S. for the migrant cohort or the Philippines for the non-migrant cohort. At baseline, interviewers administered semi-structured questionnaires that assessed demographic characteristics, diet, physical activity, stress, and immigration experiences. Interviewers also measured weight, height, waist and hip circumferences, blood pressure, and collected dried blood spot samples.DiscussionMigrants enrolled in the study appear to be representative of recent Filipino migrants to the U.S. Additionally, migrant and non-migrant study participants are comparable on several characteristics that we attempted to balance at baseline, including age, gender, and education. HoPES is a unique study that approximates a natural experiment from which to study the effects of immigration on obesity and other health problems. A number of innovative methodological strategies were pursued to expand the boundaries of current immigrant health research. Key to accomplishing this research was investment in building collaborative relationships with stakeholders across the U.S. and the Philippines with shared interest in the health of migrants

    Exploring the Mastery Level of Critical Thinking and Problem Solving Skill Among the Technical Undergraduate

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    Statistics from the Department of Statistics showed that 76200 graduates in this country still failed to get a job. One of the main reasons of this phenomenon is the graduates are still unable to meet the demand of the current job market. The current job market is not only take seriously on knowledge and technical skills but also soft skills. Therefore, the Ministry of Higher Education (MOHE) listed seven soft skills that should be possessed by the graduates. Among the seven soft skills, critical thinking and problem solving is the one of the emphasized skill. In this skills, there are three main subskills must be mastery from a total number subskills of seven. Thus, a survey was conducted to identify the level of critical thinking and problem solving skills among the engineering undergraduate students. A total of 341 final year students of Bachelor's degree in Universiti Tun Hussein Onn Malaysia were stratified randomly selected as respondents. Data was collected through an achievement test on critical thinking and problem solving skills. Mean, standard deviation, Mann Whitney U test and Kruskal Wallis Test were employed to analyze the gathered data. Results showed that the level of critical thinking and problem solving skills of students for the three main subskills (Ability to Identify and Analyse Problem in Complex or Ambiguous Situation and Develop Justification Evaluation; Ability to Improve and Develop  Thinking Skill as Explain, Analyse and Discussion Evaluated; Ability to Generate  the Ideas and Alternative Evaluation) were at a moderate level. As the conclusion, the MOHE, education institutions and students must work together in order to enhance the acquisition for critical thinking and problem solving skill of graduates through the modification of teaching strategies, strengthening academic programs and others intervention programme
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