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This study developed a 5-step vocabulary learning (FSVL) strategy and a mobile learning tool in a situational English vocabulary learning environment and assessed their effects on the learning motivation and performance of English as a foreign language (EFL) students in a situational English vocabulary learning environment. Overall, 80 EFL students and 1 teacher participated in this study. Two learning methods were implemented. The first involved employing the FSVL strategy and the mobile learning tool in a situational English vocabulary learning environment, and the other method involved employing the FSVL strategy and traditional learning tools in a situational English vocabulary learning environment. Data were collected by conducting interviews and tests and administering the Attention, Relevance, Confidence, and Satisfaction motivation questionnaire. The results showed that the learning motivation and performance of students taught using the FSVL strategy and mobile learning tool were superior to those of students taught using the FSVL strategy and traditional learning tools in a situational English vocabulary learning environment.

In Taiwan elementary schools, Scratch programming has been taught for more than four years. Previous studies have shown that personal annotations is a useful learning method that improve learning performance. An annotation-based Scratch programming (ASP) system provides for the creation, share, and review of annotations and homework solutions in the interface of Scratch programming. In addition, we combine the ASP system with the problem solving-based teaching approach in Scratch programming pedagogy, which boosts cognition development and enhances learning achievements. This study is aimed at exploring the effects of annotations and homework on learning achievement. A quasi-experimental method was used with elementary school students in a Scratch programming course over a 4-month period. The experimental results revealed that students' thoughts and solutions in solving homework assignments have a significant influence on learning achievement. We further investigated that only making annotations in solving homework activities, among all other variables (the quantity of annotations, the quantity of one's own annotations reviewed, the quantity of peers' annotations reviewed, the quantity of one's own homework solutions reviewed, and the quantity of peers' homework solutions reviewed), can significantly predict learning achievements.

This study investigates the impact of a 3D virtual learning environment based on Second Life on student motivation and achievement in learning English as a second language. Twenty-one university students participate in this study, with the support of an English instructor. The Motivated Strategies for Learning Questionnaire (MSLQ) was used to evaluate students’ intrinsic and extrinsic goal orientation and self-efficacy in Second Life. The pre-test and post-test were used to assess students’ learning achievement. The results showed that students’ intrinsic and extrinsic goal orientations in English learning in Second Life had a positive influence on their self-efficacy. In addition, students’ self-efficacy of English learning in Second Life was found to positively relate to their learning achievement. Moreover, students’ intrinsic and extrinsic goal orientations were found to significantly influence their learning achievement via self-efficacy. In other words, instructors can utilize Second Life to enhance student motivation and achievement in English learning.

MOOCs social media has appealed to most instructors and learners like strong magnets by using ubiquitous handheld devices to share and discuss films, pictures, and messages. Through the social platform, users can share, track, and search for the information of their specific interests. Thus, they can make interactive discussions as well as social learning on multimedia texts and learning materials. It provides teachers and students the social platform to express opinions or ask questions. We developed an assistant system to help students evaluate problems and solutions is an emerging issue, and the MOOCs social searching system is a key solution. We report a case study that focuses on MOOCs learners' social searching results and its influence on learning behaviors and learning outcomes. A case study was carried out with 36 high school students in Northern Taiwan. Results show that the mechanism benefits student information gathering and improves learning performance.

Birth of a black-hole relativistic jet Two groups report observations of the X-ray source Swift J164449.3+573451, which was discovered when it triggered the Swift Burst Alert Telescope on 28 March 2011. Burrows et al . report that the source has increased in brightness in the X-ray band more than 10,000-fold since 1990, and by more than 100-fold since early 2010. They conclude that we are observing the onset of relativistic jet activity from a supermassive black hole. Zauderer et al . arrive at a similar conclusion based on their observation of a radio transient associated with the source, and extensive monitoring at centimetre to millimetre wavelengths during the first month of its evolution. They estimate the mass of the black hole at around 10 6 solar masses. Supermassive black holes have powerful gravitational fields with strong gradients that can destroy stars that get too close 1 , 2 , producing a bright flare in ultraviolet and X-ray spectral regions from stellar debris that forms an accretion disk around the black hole 3 , 4 , 5 , 6 , 7 . The aftermath of this process may have been seen several times over the past two decades in the form of sparsely sampled, slowly fading emission from distant galaxies 8 , 9 , 10 , 11 , 12 , 13 , 14 , but the onset of the stellar disruption event has not hitherto been observed. Here we report observations of a bright X-ray flare from the extragalactic transient Swift J164449.3+573451. This source increased in brightness in the X-ray band by a factor of at least 10,000 since 1990 and by a factor of at least 100 since early 2010. We conclude that we have captured the onset of relativistic jet activity from a supermassive black hole. A companion paper 15 comes to similar conclusions on the basis of radio observations. This event is probably due to the tidal disruption of a star falling into a supermassive black hole, but the detailed behaviour differs from current theoretical models of such events.

Colonization with methicillin-resistant Staphylococcus aureus is associated with increased infection risk after hospital discharge. In a multicenter, randomized trial, a program of MRSA decolonization at home led to a significantly lower risk of MRSA infection over a 1-year period than hygiene education alone.

The lack of a specific biomarker makes preclinical diagnosis of Alzheimer's disease (AD) impossible, and it precludes assessment of therapies aimed at preventing or reversing the course of the disease. The development of a tool that enables direct, quantitative detection of the amyloid-β deposits found in the disease would provide an excellent biomarker. This article demonstrates the real-time biodistribution kinetics of an imaging agent in transgenic mouse models of AD. Using multiphoton microscopy, Pittsburgh compound B (PIB) was imaged with sub-µm resolution in the brains of living transgenic mice during peripheral administration. PIB entered the brain quickly and labeled amyloid deposits within minutes. The nonspecific binding was cleared rapidly, whereas specific labeling was prolonged. WT mice showed rapid brain entry and clearance of PIB without any binding. These results demonstrate that the compound PIB has the properties required for a good amyloid-imaging agent in humans with or at risk for AD.

The shark and ray (Elasmobranchii) trade is a commercially valuable industry that has negative consequences for wild populations. An estimated 100 million sharks are caught each year to supply the demand for cultural cuisines, traditions and practices, including shark fin soup and Traditional Chinese Medicine. Despite the establishment of frameworks and regulations by international trade and conservation bodies as well as national legislations, elasmobranch populations continue to decline. While their conservation becomes an ever more pressing concern, a major obstacle that hampers regulation is the mislabelling and/or misidentification of dried products or carcasses that have had fins removed. Here we use DNA barcoding to identify the species of origin for a variety of shark and ray products readily available to consumers in Singapore, a major importer of these goods. We amplified a fragment of the cytochrome c oxidase subunit I gene from shark fin, cartilage and meat, as well as ray gill plates and meat for DNA sequencing. Our analysis of 207 DNA barcodes yielded 28 positively identified elasmobranch species, eight of which are listed under Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora, and 12 are listed as Endangered or Vulnerable by the International Union for the Conservation of Nature. This information will be useful to regulatory bodies in controlling trade and establishing new or revisiting previous conservation status listings.

We present a comprehensive analysis of a bright, long duration (T90 ~ 257 s) GRB 110205A at redshift z= 2.22. The optical prompt emission was detected by Swift/UVOT, ROTSE-IIIb and BOOTES telescopes when the GRB was still radiating in the gamma-ray band. Nearly 200 s of observations were obtained simultaneously from optical, X-ray to gamma-ray, which makes it one of the exceptional cases to study the broadband spectral energy distribution across 6 orders of magnitude in energy during the prompt emission phase. By fitting the time resolved prompt spectra, we clearly identify, for the first time, an interesting two-break energy spectrum, roughly consistent with the standard GRB synchrotron emission model in the fast cooling regime. Although the prompt optical emission is brighter than the extrapolation of the best fit X/gamma-ray spectra, it traces the gamma-ray light curve shape, suggesting a relation to the prompt high energy emission. The synchrotron + SSC scenario is disfavored by the data, but the models invoking a pair of internal shocks or having two emission regions can interpret the data well. Shortly after prompt emission (~ 1100 s), a bright (R = 14.0) optical emission hump with very steep rise (alpha ~ 5.5) was observed which we interpret as the emission from the reverse shock. It is the first time that the rising phase of a reverse shock component has been closely observed. The full optical and X-ray afterglow lightcurves can be interpreted within the standard reverse shock (RS) + forward shock (FS) model. In general, the high quality prompt emission and afterglow data allow us to apply the standard fireball shock model to extract valuable information about the GRB including the radiation mechanism, radius of prompt emission R, initial Lorentz factor of the outflow, the composition of the ejecta, as well as the collimation angle and the total energy budget.

Massive black holes are believed to reside at the centres of most galaxies. They can be- come detectable by accretion of matter, either continuously from a large gas reservoir or impulsively from the tidal disruption of a passing star, and conversion of the gravitational energy of the infalling matter to light. Continuous accretion drives Active Galactic Nuclei (AGN), which are known to be variable but have never been observed to turn on or off. Tidal disruption of stars by dormant massive black holes has been inferred indirectly but the on- set of a tidal disruption event has never been observed. Here we report the first discovery of the onset of a relativistic accretion-powered jet in the new extragalactic transient, Swift J164449.3+573451. The behaviour of this new source differs from both theoretical models of tidal disruption events and observations of the jet-dominated AGN known as blazars. These differences may stem from transient effects associated with the onset of a powerful jet. Such an event in the massive black hole at the centre of our Milky Way galaxy could strongly ionize the upper atmosphere of the Earth, if beamed towards us.