Sample records for sun-earth l2 point

  1. Flights between a neighborhoods of unstable libration points of Sun-Earth system (United States)

    Surkova, Valerya; Shmyrov, Vasily


    In this paper we study the problem of constructing impulse flights between neighborhoods of unstable collinear libration points of the Sun-Earth system [1]. Such maneuvering in near-Earth space may prove to be in demand in modern space navigation. For example, such a maneuvering was done by the space vehicle GENESIS. Three test points are chosen for the implementation of the impulse control, in order to move to a neighborhood of the libration point L2. It is shown that the earlier on the exit from the vicinity of the libration point L1 impulse control was realized, the sooner the neighborhood L2 was achieved. Separated from this problem, the problem of optimal control in the neighborhood of L2 was considered and a form of stabilizing control is presented.

  2. Understanding the Sun-Earth Libration Point Orbit Formation Flying Challenges For WFIRST and Starshade (United States)

    Webster, Cassandra M.; Folta, David C.


    In order to fly an occulter in formation with a telescope at the Sun-Earth L2 (SEL2) Libration Point, one must have a detailed understanding of the dy-namics that govern the restricted three body system. For initial purposes, a linear approximation is satisfactory, but operations will require a high-fidelity modeling tool along with strategic targeting methods in order to be successful. This paper focuses on the challenging dynamics of the transfer trajectories to achieve the relative positioning of two spacecraft to fly in formation at SEL2, in our case, the Wide-Field Infrared Survey Telescope (WFIRST) and a proposed Starshade. By modeling the formation transfers using a high fidelity tool, an accurate V approximation can be made to as-sist with the development of the subsystem design required for a WFIRST and Starshade formation flight mission.

  3. The Sun-Earth saddle point: characterization and opportunities to test general relativity (United States)

    Topputo, Francesco; Dei Tos, Diogene A.; Rasotto, Mirco; Nakamiya, Masaki


    The saddle points are locations where the net gravitational accelerations balance. These regions are gathering more attention within the astrophysics community. Regions about the saddle points present clean, close-to-zero background acceleration environments where possible deviations from General Relativity can be tested and quantified. Their location suggests that flying through a saddle point can be accomplished by leveraging highly nonlinear orbits. In this paper, the geometrical and dynamical properties of the Sun-Earth saddle point are characterized. A systematic approach is devised to find ballistic orbits that experience one or multiple passages through this point. A parametric analysis is performed to consider spacecraft initially on L_{1,2} Lagrange point orbits. Sun-Earth saddle point ballistic fly-through trajectories are evaluated and classified for potential use. Results indicate an abundance of short-duration, regular solutions with a variety of characteristics.

  4. Science Enabled by the Ares V: A Large Monolithic Telescope Placed at the Second Sun-Earth Lagrange Point (United States)

    Hopkins, Randall C.; Stahl, H. Philip


    The payload mass and volume capabilities of the planned Ares V launch vehicle provide the science community with unprecedented opportunities to place large science payloads into low earth orbit and beyond. One example, the outcome of a recent study conducted at the NASA Marshall Space Flight Center, is a large, monolithic telescope with a primary mirror diameter of 6.2 meters placed into a halo orbit about the second Sun-Earth Lagrange point, or L2, approximately 1.5 million kin beyond Earth's orbit. Operating in the visible and ultraviolet regions of the electromagnetic spectrum, such a large telescope would allow astronomers to detect bio-signatures and characterize the atmospheres of transiting exoplanets, provide high resolution imaging three or more times better than the Hubble Space Telescope and the James Webb Space Telescope, and observe the ultraviolet light from warm baryonic matter.

  5. How to use the Sun-Earth Lagrange points for fundamental physics and navigation (United States)

    Tartaglia, A.; Lorenzini, E. C.; Lucchesi, D.; Pucacco, G.; Ruggiero, M. L.; Valko, P.


    We illustrate the proposal, nicknamed LAGRANGE, to use spacecraft, located at the Sun-Earth Lagrange points, as a physical reference frame. Performing time of flight measurements of electromagnetic signals traveling on closed paths between the points, we show that it would be possible: (a) to refine gravitational time delay knowledge due both to the Sun and the Earth; (b) to detect the gravito-magnetic frame dragging of the Sun, so deducing information about the interior of the star; (c) to check the possible existence of a galactic gravitomagnetic field, which would imply a revision of the properties of a dark matter halo; (d) to set up a relativistic positioning and navigation system at the scale of the inner solar system. The paper presents estimated values for the relevant quantities and discusses the feasibility of the project analyzing the behavior of the space devices close to the Lagrange points.

  6. Investigating Trojan Asteroids at the L4/L5 Sun-Earth Lagrange Points (United States)

    John, K. K.; Graham, L. D.; Abell, P. A.


    Investigations of Earth's Trojan asteroids will have benefits for science, exploration, and resource utilization. By sending a small spacecraft to the Sun-Earth L4 or L5 Lagrange points to investigate near-Earth objects, Earth's Trojan population can be better understood. This could lead to future missions for larger precursor spacecraft as well as human missions. The presence of objects in the Sun-Earth L4 and L5 Lagrange points has long been suspected, and in 2010 NASA's Wide-field Infrared Survey Explorer (WISE) detected a 300 m object. To investigate these Earth Trojan asteroid objects, it is both essential and feasible to send spacecraft to these regions. By exploring a wide field area, a small spacecraft equipped with an IR camera could hunt for Trojan asteroids and other Earth co-orbiting objects at the L4 or L5 Lagrange points in the near-term. By surveying the region, a zeroth-order approximation of the number of objects could be obtained with some rough constraints on their diameters, which may lead to the identification of potential candidates for further study. This would serve as a precursor for additional future robotic and human exploration targets. Depending on the inclination of these potential objects, they could be used as proving areas for future missions in the sense that the delta-V's to get to these targets are relatively low as compared to other rendezvous missions. They can serve as platforms for extended operations in deep space while interacting with a natural object in microgravity. Theoretically, such low inclination Earth Trojan asteroids exist. By sending a spacecraft to L4 or L5, these likely and potentially accessible targets could be identified.

  7. Solar radiation pressure application for orbital motion stabilization near the Sun-Earth collinear libration point (United States)

    Polyakhova, Elena; Shmyrov, Alexander; Shmyrov, Vasily


    Orbital maneuvering in a neighborhood of the collinear libration point L1 of Sun-Earth system has specific properties, primarily associated with the instability L1. For a long stay in this area of space the stabilization problem of orbital motion requires a solution. Numerical experiments have shown that for stabilization of motion it is requires very small control influence in comparison with the gravitational forces. On the other hand, the stabilization time is quite long - months, and possibly years. This makes it highly desirable to use solar pressure forces. In this paper we illustrate the solar sail possibilities for solving of stabilization problem in a neighborhood L1 with use of the model example.

  8. Optimal Sunshade Configurations for Space-Based Geoengineering near the Sun-Earth L1 Point. (United States)

    Sánchez, Joan-Pau; McInnes, Colin R


    Within the context of anthropogenic climate change, but also considering the Earth's natural climate variability, this paper explores the speculative possibility of large-scale active control of the Earth's radiative forcing. In particular, the paper revisits the concept of deploying a large sunshade or occulting disk at a static position near the Sun-Earth L1 Lagrange equilibrium point. Among the solar radiation management methods that have been proposed thus far, space-based concepts are generally seen as the least timely, albeit also as one of the most efficient. Large occulting structures could potentially offset all of the global mean temperature increase due to greenhouse gas emissions. This paper investigates optimal configurations of orbiting occulting disks that not only offset a global temperature increase, but also mitigate regional differences such as latitudinal and seasonal difference of monthly mean temperature. A globally resolved energy balance model is used to provide insights into the coupling between the motion of the occulting disks and the Earth's climate. This allows us to revise previous studies, but also, for the first time, to search for families of orbits that improve the efficiency of occulting disks at offsetting climate change on both global and regional scales. Although natural orbits exist near the L1 equilibrium point, their period does not match that required for geoengineering purposes, thus forced orbits were designed that require small changes to the disk attitude in order to control its motion. Finally, configurations of two occulting disks are presented which provide the same shading area as previously published studies, but achieve reductions of residual latitudinal and seasonal temperature changes.

  9. Optimal Sunshade Configurations for Space-Based Geoengineering near the Sun-Earth L1 Point.

    Directory of Open Access Journals (Sweden)

    Joan-Pau Sánchez

    Full Text Available Within the context of anthropogenic climate change, but also considering the Earth's natural climate variability, this paper explores the speculative possibility of large-scale active control of the Earth's radiative forcing. In particular, the paper revisits the concept of deploying a large sunshade or occulting disk at a static position near the Sun-Earth L1 Lagrange equilibrium point. Among the solar radiation management methods that have been proposed thus far, space-based concepts are generally seen as the least timely, albeit also as one of the most efficient. Large occulting structures could potentially offset all of the global mean temperature increase due to greenhouse gas emissions. This paper investigates optimal configurations of orbiting occulting disks that not only offset a global temperature increase, but also mitigate regional differences such as latitudinal and seasonal difference of monthly mean temperature. A globally resolved energy balance model is used to provide insights into the coupling between the motion of the occulting disks and the Earth's climate. This allows us to revise previous studies, but also, for the first time, to search for families of orbits that improve the efficiency of occulting disks at offsetting climate change on both global and regional scales. Although natural orbits exist near the L1 equilibrium point, their period does not match that required for geoengineering purposes, thus forced orbits were designed that require small changes to the disk attitude in order to control its motion. Finally, configurations of two occulting disks are presented which provide the same shading area as previously published studies, but achieve reductions of residual latitudinal and seasonal temperature changes.

  10. Early Mission Maneuver Operations for the Deep Space Climate Observatory Sun-Earth L1 Libration Point Mission (United States)

    Roberts, Craig; Case, Sara; Reagoso, John; Webster, Cassandra


    The Deep Space Climate Observatory mission launched on February 11, 2015, and inserted onto a transfer trajectory toward a Lissajous orbit around the Sun-Earth L1 libration point. This paper presents an overview of the baseline transfer orbit and early mission maneuver operations leading up to the start of nominal science orbit operations. In particular, the analysis and performance of the spacecraft insertion, mid-course correction maneuvers, and the deep-space Lissajous orbit insertion maneuvers are discussed, com-paring the baseline orbit with actual mission results and highlighting mission and operations constraints..

  11. A Small Mission Concept to the Sun-Earth Lagrangian L5 Point for Innovative Solar, Heliospheric and Space Weather Science (United States)

    Lavraud, B.; Liu, Y.; Segura, K.; He, J.; Qin, G.; Temmer, M.; Vial, J.-C.; Xiong, M.; Davies, J. A.; Rouillard, A. P.; hide


    We present a concept for a small mission to the Sun-Earth Lagrangian L5 point for innovative solar, heliospheric and space weather science. The proposed INvestigation of Solar-Terrestrial Activity aNd Transients (INSTANT) mission is designed to identify how solar coronal magnetic fields drive eruptions, mass transport and particle acceleration that impact the Earth and the heliosphere. INSTANT is the first mission designed to (1) obtain measurements of coronal magnetic fields from space and (2) determine coronal mass ejection (CME) kinematics with unparalleled accuracy. Thanks to innovative instrumentation at a vantage point that provides the most suitable perspective view of the Sun-Earth system, INSTANT would uniquely track the whole chain of fundamental processes driving space weather at Earth. We present the science requirements, payload and mission profile that fulfill ambitious science objectives within small mission programmatic boundary conditions.

  12. Sun, Earth and Sky

    CERN Document Server

    Lang, Kenneth R


    This Second Edition of Sun, Earth and Sky updates the popular text by providing comprehensive accounts of the most recent discoveries made by five modern solar spacecraft during the past decade. Their instruments have used sound waves to peer deep into the Sun’s inner regions and measure the temperature of its central nuclear reactor, and extended our gaze far from the visible Sun to record energetic outbursts that threaten Earth. Breakthrough observations with the underground Sudbury Neutrino Observatory are also included, which explain the new physics of ghostly neutrinos and solve the problematic mismatch between the predicted and observed amounts of solar neutrinos. This new edition of Sun, Earth and Sky also describes our recent understanding of how the Sun’s outer atmosphere is heated to a million degrees, and just where the Sun’s continuous winds come from. As humans we are more intimately linked with our life-sustaining Sun than with any other astronomical object, and the new edition therefore p...

  13. Sun-Earth Day, 2001 (United States)

    Adams, Mitzi L.; Mortfield, P.; Hathaway, D. H.; Whitaker, Ann F. (Technical Monitor)


    To promote awareness of the Sun-Earth connection, NASA's Marshall Space Flight Center, in collaboration with the Stanford SOLAR Center, sponsored a one-day Sun-Earth Day event on April 27, 2001. Although "celebrated" on only one day, teachers and students from across the nation, prepared for over a month in advance. Workshops were held in March to train teachers. Students performed experiments, results of which were shared through video clips and an internet web cast. Our poster includes highlights from student experiments (grades 2 - 12), lessons learned from the teacher workshops and the event itself, and plans for Sun-Earth Day 2002.

  14. Sun-Earth Scientists and Native Americans Collaborate on Sun-Earth Day (United States)

    Ng, C. Y.; Lopez, R. E.; Hawkins, I.


    Sun-Earth Connection scientists have established partnerships with several minority professional societies to reach out to the blacks, Hispanics and Native American students. Working with NSBP, SACNAS, AISES and NSHP, SEC scientists were able to speak in their board meetings and national conferences, to network with minority scientists, and to engage them in Sun-Earth Day. Through these opportunities and programs, scientists have introduced NASA research results as well indigenous views of science. They also serve as role models in various communities. Since the theme for Sun-Earth Day 2005 is Ancient Observatories: Timeless Knowledge, scientists and education specialists are hopeful to excite many with diverse backgrounds. Sun-Earth Day is a highly visible annual program since 2001 that touches millions of students and the general public. Interviews, classroom activities and other education resources are available on the web at

  15. Sun-Earth Day Connects History, Culture and Science (United States)

    Cline, T.; Thieman, J.


    The NASA Sun-Earth Connection Education forum annually promotes and event called Sun-Earth Day: a national celebration of the Sun, the space around the Earth (geospace), and how all of it affects life on our planet. For the past 3 years this event has provided a venue by which classrooms, museums, planetaria, and at NASA centers have had a sensational time sharing stories, images, and activities related to the Sun-Earth connections and the views o fthe Sun from Earth. Each year we select a different theme by which NASA Space Science can be further related to cross-curricular activities. Sun-Earth Day 2002, "Celebrate the Equinox", drew parallels between Native American Cultures and NASA's Sun-Earth Connection research via cultural stories, interviews, web links, activities and Native American participation. Sun-Earth Day 2003, "Live From the Aurora", shared the beauty of the Aurora through a variety of activities and stories related to perspectives of Northern Peoples. Sun-Earth Day 2004 will share the excitement of the transit of Venus through comparisons of Venus with Earth and Mars, calculations of the distances to nearby stars, and the use of transits to identify extra-solar planets. Finally, Sun-Earth Day 2005 will bring several of these themes together by turning our focus to the history and culture surrounding ancient observatories such as Chaco Canyon, Machu Picchu, and Chichen Itza.

  16. Advances in Sun-Earth Connection Modeling

    International Nuclear Information System (INIS)

    Ganguli, S.B.; Gavrishchaka, V.V.


    Space weather forecasting is a focus of a multidisciplinary research effort motivated by a sensitive dependence of many modern technologies on geospace conditions. Adequate understanding of the physics of the Sun-Earth connection and associated multi-scale magnetospheric and ionospheric processes is an essential part of this effort. Modern physical simulation models such as multimoment multifluid models with effective coupling from small-scale kinetic processes can provide valuable insight into the role of various physical mechanisms operating during geomagnetic storm/substorm activity. However, due to necessary simplifying assumptions, physical models are still not well suited for accurate real-time forecasting. Complimentary approach includes data-driven models capable of efficient processing of multi-scale spatio-temporal data. However, the majority of advanced nonlinear algorithms, including neural networks (NN), can encounter a set of problems called dimensionality curse when applied to high-dimensional data. Forecasting of rare/extreme events such as large geomagnetic storms/substorms is of the most practical importance but is also very challenging for many existing models. A very promising algorithm that combines the power of the best nonlinear techniques and tolerance to high-dimensional and incomplete data is support vector machine (SVM). We have summarized advantages of the SVM and described a hybrid model based on SVM and extreme value theory (EVT) for rare event forecasting. Results of the SVM application to substorm forecasting and future directions are discussed

  17. Sun-Earth Day 2005: Ancient Observatories: Timeless Knowledge (United States)

    Thieman, J. R.; Cline, T.; Lewis, E.; Hawkins, I.; Odenwald, S.; Mayo, L.


    The NASA Sun-Earth Connection Education Forum (SECEF) annually promotes an event called Sun-Earth Day. For Sun-Earth Day 2005 SECEF has selected a theme called "Ancient Observatories: Timeless Knowledge. This year's Sun-Earth Day theme is your ticket to a fascinating journey through time as we explore centuries of sun watching by a great variety of cultures. From ancient solar motion tracking to modern solar activity monitoring the Sun has always occupied an important spot in mankind's quest to understand the Universe. Sun-Earth Day events usually are centered on the spring equinox around March 21, but this year there has already been a webcast from the San Francisco Exploratorium and the Native American ruins at Chaco Canyon, New Mexico on the day of winter solstice 2004. There will be another webcast on March 20 live from Chichen Itza, Mexico highlighting the solar alignment that makes a serpent appear on one of the ancient pyramids. The website has been developed to provide the necessary resources and opportunities for participation by scientists and educators in giving school or general public programs about Sun-Earth Day. The goal is to involve as much of the student population and the public in this event as possible and to help them understand the importance of the Sun for ancient and modern peoples. Through engaging activities available on the website, classrooms and museums can create their own event or participate in one of the opportunities we make available. Scientists, educators, amateur astronomers, and museums are invited to register on the website to receive a free packet of materials about Sun-Earth Day for use in making presentations or programs about the event. Past and future Sun-Earth Days will be discussed as well.

  18. Dynamics of the Sun-Earth-Moon System

    Indian Academy of Sciences (India)

    The dynamics of the Sun-Earth-Moon system is discussed with special attention to the effects of. Sun's perturbations on the Moon's orbit around the Earth. Important secular effects are the re- gression of the nodes, the advance of the perigee and the increase in the Moon's mean longitude. We discuss the relationship of the ...

  19. Sun-Earth Day - Teaching Heliophysics Through Education Technology (United States)

    Thieman, J.; Cline, T.; Lewis, E.


    Sun-Earth Day (SED) is an Education and Outreach program supported by the U.S, National Aeronautics and Space Administration (NASA). The intent of the program is to teach students and the general public about Heliophysics (the science of the study of the Sun, how it varies, and how solar dynamics affect the rest of the solar system, especially the Earth). The program was begun ten years ago. Each year since that time a particular day has been designated as "Sun-Earth Day ,,. Usually the day of the spring equinox (March 20 or 21) is Sun-Earth Day, but other days have been used as well. Each year a theme is chosen relating to Heliophysics and events reflecting that theme are planned not only for Sun-Earth Day, but for the entire year. From the very beginning educational technology was emphasized in the events in order to effectively reach wide audiences with the SED message. The main approach has been to have a "webcast" related to each year's theme, often from a location that supports the theme as well. For example, a webcast took place from the Mayan pyramids at Chichen Itza, Mexico to highlight the theme of "Ancient Observatories, Timeless Knowledge". Webcasts were not the only technology employed, however. Many of the themes centered on the dynamic nature of the Sun and the effects that solar storms can have on interplanetary space and in our day-to-day life on Earth. Activities for tracking when solar storms happen and how they affect the Earth were developed and brought together in an educational package called Space Weather Action Centers. This project is explained in more detail in another presentation in this session being given by Norma Teresinha Oliveira Reis. Recent Sun-Earth Days have utilized "social networking" technologies to reach widespread groups on the internet. Podcasts, Vodcasts, Facebook, Twitter, and Second Life are the types of network technologies being employed now. The NASA Distance learning Network is another method for bringing Sun-Earth

  20. A Small Spacecraft Swarm Deployment and Stationkeeping Strategy for Sun-Earth L1 Halo Orbits (United States)

    Renea Conn, Tracie; Bookbinder, Jay


    Spacecraft orbits about the Sun-Earth librarian point L1 have been of interest since the 1950s. An L1 halo orbit was first achieved with the International Sun-Earth Explorer-3 (ISEE-3) mission, and similar orbits around Sun-Earth L1 were achieved in the Solar and Heliospheric Observatory (SOHO), Advanced Composition Explorer (ACE), Genesis, and Deep Space Climate Observatory (DSCOVR) missions. With recent advancements in CubeSat technology, we envision that it will soon be feasible to deploy CubeSats at L1. As opposed to these prior missions where one large satellite orbited alone, a swarm of CubeSats at L1 would enable novel science data return, providing a topology for intersatellite measurements of heliophysics phenomena both spatially and temporally, at varying spatial scales.The purpose of this iPoster is to present a flight dynamics strategy for a swarm of numerous CubeSats orbiting Sun-Earth L1. The presented method is a coupled, two-part solution. First, we present a deployment strategy for the CubeSats that is optimized to produce prescribed, time-varying intersatellite baselines for the purposes of collecting magnetometer data as well as radiometric measurements from cross-links. Second, we employ a loose control strategy that was successfully applied to SOHO and ACE for minimized stationkeeping propellant expenditure. We emphasize that the presented solution is practical within the current state-of-the-art and heritage CubeSat technology, citing capabilities of CubeSat designs that will launch on the upcoming Exploration Mission 1 (EM-1) to lunar orbits and beyond. Within this iPoster, we present animations of the simulated deployment strategy and resulting spacecraft trajectories. Mission design parameters such as total Δv required for long-term station keeping and minimum/maximum/mean spacecraft separation distances are also presented.

  1. Challenges in Modeling the Sun-Earth System (United States)

    Spann, James


    The transfer of mass, energy and momentum through the coupled Sun-Earth system spans a wide range of scales in time and space. While profound advances have been made in modeling isolated regions of the Sun-Earth system, minimal progress has been achieved in modeling the end-to-end system. Currently, end-to-end modeling of the Sun-Earth system is a major goal of the National Space Weather and NASA Living With a Star (LWS) programs. The uncertainty in the underlying physics responsible for coupling contiguous regions of the Sun-Earth system is recognized as a significant barrier to progress. Our limited understanding of the underlying coupling physics is illustrated by the following example questions: how does the propagation of a typical CME/solar flare influence the measured properties of the solar wind at 1 AU? How does the solar wind compel the dynamic response of the Earth's magnetosphere? How is variability in the ionosphere-thermosphere system coupled to magnetospheric variations? Why do these and related important questions remain unanswered? What are the primary problems that need to be resolved to enable significant progress in comprehensive modeling of the Sun-Earth system? Which model/technique improvements are required and what new data coverage is required to enable full model advances? This poster opens the discussion for how these and other important questions can be addressed. A workshop scheduled for October 8-22, 2004 in Huntsville, Alabama, will be a forum for identifying ana exploring promising new directions and approaches for characterizing and understanding the system. To focus the discussion, the workshop will emphasize the genesis, evolution, propagation and interaction of high-speed solar wind streamers or CME/flares with geospace and the subsequent response of geospace from its outer reaches in the magnetosphere to the lower edge of the ionosphere-mesosphere-thermosphere. Particular emphasis will be placed on modeling the coupling aspects

  2. Use of libration-point orbits for space observatories (United States)

    Farquhar, Robert W.; Dunham, David W.


    The sun-earth libration points, L1 and L2, are located 1.5 million kilometers from the earth toward and away from the sun. Halo orbits about these points have significant advantages for space observatories in terms of viewing geometry, thermal and radiation environment, and delta-V expediture.

  3. Sun-earth connection education through modern views of ancient (United States)

    Thieman, J. R.

    The NASA Sun-Earth Connection Education Forum (SECEF) has the responsibility of using the latest science results from the study of solar physics, space physics, and aeronomy to inspire students in the classroom and to inform the public in general. SECEF works with NASA's Sun-Earth Connection spaceflight missions to accomplish this goal. Each year the missions and SECEF combine to promote their science through a major event designed to attract the attention of all. In late 2004 and 2005 the event will be the study of solar observatories created by ancient peoples and a comparison of their knowledge and culture to present understanding. Two solar observatory sites will be featured, Chaco Canyon in the U.S. and Chichen Itza in Mexico. There are many other places throughout the world that could also be featured as solar observatories and some of these may be described on the SECEF web site or used in future occurrences. Special emphasis is placed on events associated with the solstice and equinox dates. It is hoped that there will be happenings around the world on these days and SECEF will work with many museums, science centers, and other groups to help make this happen. Plans for the 2005 Ancient Observatories event and possible future events on the same subject will be described.

  4. The Sun/Earth System and Space Weather (United States)

    Poland, Arthur I.; Fox, Nicola; Lucid, Shannon


    Solar variability and solar activity are now seen as significant drivers with respect to the Earth and human technology systems. Observations over the last 10 years have significantly advanced our understanding of causes and effects in the Sun/Earth system. On a practical level the interactions between the Sun and Earth dictate how we build our systems in space (communications satellites, GPS, etc), and some of our ground systems (power grids). This talk will be about the Sun/Earth system: how it changes with time, its magnetic interactions, flares, the solar wind, and how the Sun effects human systems. Data will be presented from some current spacecraft which show, for example, how we are able to currently give warnings to the scientific community, the Government and industry about space storms and how this data has improved our physical understanding of processes on the Sun and in the magnetosphere. The scientific advances provided by our current spacecraft has led to a new program in NASA to develop a 'Space Weather' system called 'Living With a Star'. The current plan for the 'Living With a Star' program will also be presented.

  5. Lunar and Lagrangian Point L1 L2 CubeSat Communication and Navigation Considerations (United States)

    Schaire, Scott; Wong, Yen F.; Altunc, Serhat; Bussey, George; Shelton, Marta; Folta, Dave; Gramling, Cheryl; Celeste, Peter; Anderson, Mile; Perrotto, Trish; hide


    CubeSats have grown in sophistication to the point that relatively low-cost mission solutions could be undertaken for planetary exploration. There are unique considerations for lunar and L1/L2 CubeSat communication and navigation compared with low earth orbit CubeSats. This paper explores those considerations as they relate to the Lunar IceCube Mission. The Lunar IceCube is a CubeSat mission led by Morehead State University with participation from NASA Goddard Space Flight Center, Jet Propulsion Laboratory, the Busek Company and Vermont Tech. It will search for surface water ice and other resources from a high inclination lunar orbit. Lunar IceCube is one of a select group of CubeSats designed to explore beyond low-earth orbit that will fly on NASA’s Space Launch System (SLS) as secondary payloads for Exploration Mission (EM) 1. Lunar IceCube and the EM-1 CubeSats will lay the groundwork for future lunar and L1/L2 CubeSat missions. This paper discusses communication and navigation needs for the Lunar IceCube mission and navigation and radiation tolerance requirements related to lunar and L1/L2 orbits. Potential CubeSat radios and antennas for such missions are investigated and compared. Ground station coverage, link analysis, and ground station solutions are also discussed. This paper will describe modifications in process for the Morehead ground station, as well as further enhancements of the Morehead ground station and NASA Near Earth Network (NEN) that are being considered. The potential NEN enhancements include upgrading current NEN Cortex receiver with Forward Error Correction (FEC) Turbo Code, providing X-band uplink capability, and adding ranging options. The benefits of ground station enhancements for CubeSats flown on NASA Exploration Missions (EM) are presented. This paper also describes how the NEN may support lunar and L1/L2 CubeSats without any enhancements. In addition, NEN is studying other initiatives to better support the CubeSat community

  6. Numerical simulation of the subsolar magnetopause current layer in the sun-earth meridian plane (United States)

    Okuda, H.


    The formation and stability of the magnetopause current layer near the subsolar point in the sun-earth meridian plane are examined using a 2D electromagnetic particle simulation. For the case of zero IMF, the simulation results show that the current layer remains stable and is essentially the same as in the 1D simulation. The width of the current layer is given by the electron-ion hybrid gyroradius which is much smaller than the ion gyroradius. The current layer is found to remain stable for the northward IMF as well. As in the 1D simulation, the jump of the magnetic field at the current layer for the northward IMF remains small. For the southward IMF, collisionless magnetic reconnection is found to develop, leading to the formation of magnetic islands and density peaking within the current layer.

  7. High-Performance Data Analysis Tools for Sun-Earth Connection Missions, Phase II (United States)

    National Aeronautics and Space Administration — The Interactive Data Language (IDL) is a standard tool used by many researchers in observational fields. Present day Sun-Earth Connection missions like SOHO, or...

  8. Sunwatchers Across Time: Sun-Earth Day from Ancient and Modern Solar Observatories (United States)

    Hawkins, I.; Vondrak, R.

    Humans across all cultures have venerated, observed, and studied the Sun for thousands of years. The Sun, our nearest star, provides heat and energy, is the cause of the seasons, and causes space weather effects that influence our technology-dependent society. The Sun is also part of indigenous tradition and culture. The Inca believed that the Sun had the power to make things grow, and it does, providing us with the heat and energy that are essential to our survival. From a NASA perspective, Sun-Earth Connection research investigates the effects of our active Sun on the Earth and other planets, namely, the interaction of the solar wind and other dynamic space weather phenomena with the solar system. We present plans for Sun-Earth Day 2005, a yearly celebration of the Sun-Earth Connection sponsored by the NASA Sun-Earth Connection Education Forum (SECEF). SECEF is one of four national centers of space science education and public outreach funded by NASA Office of Space Science. Sun-Earth Day involves an international audience of schools, science museums, and the general public in activities and events related to learning about the Sun-Earth Connection. During the year 2005, the program will highlight cultural and historical perspectives, as well as NASA science, through educational and public outreach events intended to involve diverse communities. Sun-Earth Day 2005 will include a series of webcasts from solar observatories produced by SECEF in partnership with the San Francisco Exploratorium. Webcasts from Chaco Culture National Historical Park in New Mexico, USA, and from Chichen Itza, Mexico, will be accessed by schools and the public. Sun-Earth Day will also feature NASA Sun-Earth Connection research, missions, and the people who make it possible. One of the goals of this talk is to inform and engage COSPAR participants in these upcoming public events sponsored by NASA. Another goal is to share best practices in public event programming, and present impact

  9. Sun-Earth Day: Growth and Impact of NASA E/PO Program (United States)

    Hawkins, I.; Thieman, J.


    Over the past six years, the NASA Sun-Earth Connection Education Forum has sponsored and coordinated education public outreach events to highlight NASA Sun-Earth Connection research and discoveries. Our strategy involves using celestial phenomena, such as total solar eclipses and the Transit of Venus to celebrate Sun-Earth Day, a popular Education and Public Outreach international program. Sun-Earth Day also focuses attention on Equinoxes and Solstices to engage K-12 schools and the general public in space science activities, demonstrations, and interactions with space scientists. In collaboration with partners that include the Exploratorium, Maryland Science Center, NASA Connect, Sun-Earth Connection missions, Ideum, and others, we produce webcasts, other multi-media, and print resources for use by school and informal educators nation-wide. We provide training and professional development to K-12 educators, museum personnel, amateur astronomers, Girl Scout leaders, etc., so they can implement their own outreach programs taking advantage of our resources. A coordinated approach promotes multiple programs occurring each year under a common theme. We will report lessons learned from several years of experience, and strategies for growth and sustainability. We will also share our plans for "Ancient Observatories - Timeless Knowledge" our theme for Sun-Earth Day 2005, which will feature solar alignments at ancient sites that mark the equinoxes and/or solstices. The video and webcast programming will feature several sites including: Chaco Canyon (New Mexico), Hovenweep (Utah), and Chichen Itza (Mexico). Many of these sites present unique opportunities to develop authentic cultural connections to Native Americans, highlighting the importance of the Sun across the ages.

  10. Challenges to modeling the Sun-Earth System: A Workshop Summary (United States)

    Spann, James F.


    This special issue of the Journal of' Atmospheric and Solar-Terrestrial Physics is a compilation of 23 papers presented at The 2004 Huntsville Modeling Workshop: Challenges to Modeling thc San-Earth System held in Huntsville, AB on October 18-22, 2004. The title of the workshop appropriately captures the theme of what was presented and discussed by the 120 participants. Currently, end-to-end modeling of the Sun-Earth system is a major goal of the National Space Weather and NASA living with a star (LWS) programs. While profound advances have been made in modeling isolated regions of the Sun-Earth system, minimal progress has been achieved in modeling the end-to-end system. The transfer of mass, energy and momentum through the coupled Sun-Earth system spans a wide range of scales inn time and space. The uncertainty in the underlying physics responsible for coupling contiguous regions of the Sun-Earth system is recognized as a significant barrier to progress

  11. Orbit Determination of Spacecraft in Earth-Moon L1 and L2 Libration Point Orbits (United States)

    Woodard, Mark; Cosgrove, Daniel; Morinelli, Patrick; Marchese, Jeff; Owens, Brandon; Folta, David


    The ARTEMIS mission, part of the THEMIS extended mission, is the first to fly spacecraft in the Earth-Moon Lissajous regions. In 2009, two of the five THEMIS spacecraft were redeployed from Earth-centered orbits to arrive in Earth-Moon Lissajous orbits in late 2010. Starting in August 2010, the ARTEMIS P1 spacecraft executed numerous stationkeeping maneuvers, initially maintaining a lunar L2 Lissajous orbit before transitioning into a lunar L1 orbit. The ARTEMIS P2 spacecraft entered a L1 Lissajous orbit in October 2010. In April 2011, both ARTEMIS spacecraft will suspend Lissajous stationkeeping and will be maneuvered into lunar orbits. The success of the ARTEMIS mission has allowed the science team to gather unprecedented magnetospheric measurements in the lunar Lissajous regions. In order to effectively perform lunar Lissajous stationkeeping maneuvers, the ARTEMIS operations team has provided orbit determination solutions with typical accuracies on the order of 0.1 km in position and 0.1 cm/s in velocity. The ARTEMIS team utilizes the Goddard Trajectory Determination System (GTDS), using a batch least squares method, to process range and Doppler tracking measurements from the NASA Deep Space Network (DSN), Berkeley Ground Station (BGS), Merritt Island (MILA) station, and United Space Network (USN). The team has also investigated processing of the same tracking data measurements using the Orbit Determination Tool Kit (ODTK) software, which uses an extended Kalman filter and recursive smoother to estimate the orbit. The orbit determination results from each of these methods will be presented and we will discuss the advantages and disadvantages associated with using each method in the lunar Lissajous regions. Orbit determination accuracy is dependent on both the quality and quantity of tracking measurements, fidelity of the orbit force models, and the estimation techniques used. Prior to Lissajous operations, the team determined the appropriate quantity of tracking

  12. Earth-Affecting Solar Causes Observatory (EASCO): a mission at the Sun-Earth L5

    DEFF Research Database (Denmark)

    Gopalswamy, Nat; Davila, Joseph M.; Auchère, Frédéric


    Observatory (STEREO) missions, but these missions lacked some key measurements: STEREO did not have a magnetograph; SOHO did not have in-situ magnetometer. SOHO and other imagers such as the Solar Mass Ejection Imager (SMEI) located on the Sun-Earth line are also not well-suited to measure Earth-directed CMEs....... The Earth-Affecting Solar Causes Observatory (EASCO) is a proposed mission to be located at the Sun-Earth L5 that overcomes these deficiencies. The mission concept was recently studied at the Mission Design Laboratory (MDL), NASA Goddard Space Flight Center, to see how the mission can be implemented....... The study found that the scientific payload (seven remote-sensing and three in-situ instruments) can be readily accommodated and can be launched using an intermediate size vehicle; a hybrid propulsion system consisting of a Xenon ion thruster and hydrazine has been found to be adequate to place the payload...

  13. Sun-Earth National Program. 2006-2009 results and prospects

    International Nuclear Information System (INIS)

    Fontaine, Dominique; Vilmer, Nicole


    PNST (Programme National Soleil-Terre/Sun-Earth National Program) is dedicated to analysis of the Sun-Earth system, from generation of the solar magnetic field, flares and coronal mass ejections, until impact on the terrestrial magnetosphere, ionosphere and thermosphere. Research activities carried out in the frame of Programme National Soleil-Terre (PNST) rely on both ground-based and space-borne instruments. One of the main objectives of PNST is to stimulate coordinated studies and to optimize scientific return of these instruments. This document is the 2006-2009 scientific report of the program. It presents in the introduction some highlights, the main questions, the thematic reviews and the forces and weaknesses of the program. Then, part 2 is a review of the main scientific questions: mechanisms at the origin of the eruptive activity in plasmas; mechanisms involved in particles heating and acceleration; energy transfers at different scales in the plasma and dynamics of turbulence in this anisotropic medium; coupling mechanisms between the different plasma envelopes; Sun-Earth relations and space meteorology; interfaces with other programs (planetary plasmas, magnetism and sun-type stars activity). Part 3 presents the results and prospects of the ground and space instrumentation, of databases and numerical tools. Finally, the administrative and financial status of the program is summarized (Program structure and operation, budget, manpower, publications)

  14. Sun-Earth Day: Reaching the Education Audience by Informal Means (United States)

    Thieman, J.; Lewis, E.; Cline, T.


    For ten years the Sun-Earth Day program has promoted Heliophysics education to ever larger audiences through events centered on attractive annual themes. What originally started out as a one day event quickly evolved into a series of programs and events that occur throughout the year culminating with a celebration on or near the Spring Equinox. The events are often formal broadcasts or webcasts seeking to convey the science behind the latest solar-terrestrial mission discoveries. This has been quite successful, but it is clear that the younger generation increasingly depends on social networking approaches and informal news transmission for learning what is happening in the world around them. For 2010, the Sun-Earth Day team put emphasis on using informal approaches to bring the theme to the audience. The main event, a webcast from the NASA booth at the National Science Teachers Association (NSTA) annual meeting by the NASA EDGE group, took a lighthearted and offbeat approach to interviewing scientists and educators about Heliophysics news. NASA EDGE programs are unscripted and unpredictable, and that represents a different approach to getting the message across. The webcast was supplemented by a number of social networking avenues. The Sun-Earth Day program explored a wide range of social media applications including Facebook, Twitter, NING, podcasting, iPhone apps, etc. Each of these offers unique and effective methods to promote Heliophysics content and mission related highlights. The facebook site was quite popular and message posting there told the Sun-Earth Day story piece by piece. The same could be said of twittering and the tweetup held at the NSTA site. Has all of this been effective? Results are still being gathered, but anecdotal responses from the world seem very positive. What other methods might be used in the future to bring the science to a personal hands-on, interactive experience? Outcomes: Participants will: (1) Be introduced to the Sun-Earth

  15. Climate and weather of the Sun-Earth system (CAWSES) highlights from a priority program

    CERN Document Server

    Lübken, Franz-Josef


    CAWSES (Climate and Weather of the Sun-Earth System) is the most important scientific program of SCOSTEP (Scientific Committee on Solar-Terrestrial Physics). CAWSES has triggered a scientific priority program within the German Research Foundation for a period of 6 years. Approximately 30 scientific institutes and 120 scientists were involved in Germany with strong links to international partners. The priority program focuses on solar influence on climate, atmospheric coupling processes, and space climatology. This book summarizes the most important results from this program covering some impor

  16. Sun-Earth National Program (PNST). 2010-2013 results and prospects

    International Nuclear Information System (INIS)


    PNST (Programme National Soleil-Terre/Sun-Earth National Program) is dedicated to analysis of the Sun-Earth system, from generation of the solar magnetic field, flares and coronal mass ejections, until impact on the terrestrial magnetosphere, ionosphere and thermosphere. Research activities carried out in the frame of Programme National Soleil-Terre (PNST) rely on both ground-based and space-borne instruments. One of the main objectives of PNST is to stimulate coordinated studies and to optimize scientific return of these instruments. This document is the 2010-2013 scientific report of the program. It presents in the introduction the main questions and the 2010-2013 highlights. The 2010-2013 results and prospects are detailed in part 2: coupling mechanisms between the different plasma envelopes; multi-scale energy transport and turbulence; plasma acceleration and heating mechanisms; eruptive or impulsive activity in plasmas; space meteorology; perspectives. Part 3 deals with the interfaces with other programs (planetary plasmas, magnetism and sun-type stars activity). Part 4 presents the means, services and tools (ground and space instrumentation, databases and numerical tools). Finally, the administrative and financial status of the program is summarized (Program structure and operation, budget, manpower, publications)

  17. SCOSTEP: Understanding the Climate and Weather of the Sun-Earth System (United States)

    Gopalswamy, Natchimuthuk


    The international solar-terrestrial physics community had recognized the importance of space weather more than a decade ago, which resulted in a number of international collaborative activities such as the Climate and Weather of the Sun Earth System (CAWSES) by the Scientific Committee on Solar Terrestrial Physics (SCOSTEP). The CAWSES program is the current major scientific program of SCOSTEP that will continue until the end of the year 2013. The CAWSES program has brought scientists from all over the world together to tackle the scientific issues behind the Sun-Earth connected system and explore ways of helping the human society. In addition to the vast array of space instruments, ground based instruments have been deployed, which not only filled voids in data coverage, but also inducted young scientists from developing countries into the scientific community. This paper presents a summary of CAWSES and other SCOSTEP activities that promote space weather science via complementary approaches in international scientific collaborations, capacity building, and public outreach.

  18. Using Solar Radiation Pressure to Control L2 Orbits (United States)

    Tene, Noam; Richon, Karen; Folta, David


    The main perturbations at the Sun-Earth Lagrange points L1 and L2 are from solar radiation pressure (SRP), the Moon and the planets. Traditional approaches to trajectory design for Lagrange-point orbits use maneuvers every few months to correct for these perturbations. The gravitational effects of the Moon and the planets are small and periodic. However, they cannot be neglected because small perturbations in the direction of the unstable eigenvector are enough to cause exponential growth within a few months. The main effect of a constant SRP is to shift the center of the orbit by a small distance. For spacecraft with large sun-shields like the Microwave Anisotropy Probe (MAP) and the Next Generation Space Telescope (NGST), the SRP effect is larger than all other perturbations and depends mostly on spacecraft attitude. Small variations in the spacecraft attitude are large enough to excite or control the exponential eigenvector. A closed-loop linear controller based on the SRP variations would eliminate one of the largest errors to the orbit and provide a continuous acceleration for use in controlling other disturbances. It is possible to design reference trajectories that account for the periodic lunar and planetary perturbations and still satisfy mission requirements. When such trajectories are used the acceleration required to control the unstable eigenvector is well within the capabilities of a continuous linear controller. Initial estimates show that by using attitude control it should be possible to minimize and even eliminate thruster maneuvers for station keeping.

  19. Student Mastery of the Sun-Earth-Moon System in a Flipped Classroom of Pre-service Elementary Education Students (United States)

    Larsen, Kristine


    One of the current trends in pedagogy at all levels(K-college) is the so-called ‘flipped classroom’, in which students prepare for a class meeting through self-study of the material. It is based on a rejection of the classic model of the faculty member as the ‘sage on the stage’ instead, responsibility for learning shifts to the individual student. The faculty member takes on the role of learning facilitator or mentor, and focuses the students’ learning by crafting and administering timely formative assessments (in multiple formats and applied multiple times) that aid both students and the faculty member in tracking the students’ mastery of the learning outcomes. In a flipped, freshman-only, section of SCI 111 Elementary Earth-Physical Sciences (a required introductory science course for pre-service elementary school teachers) the students learned through a combination of individual and group hands-on in-class activities, technology (including PowerPoint presentations and short videos viewed prior to attending class), in-class worksheets, and in-class discussions. Students self-differentiated in how they interacted with the available teaching materials, deciding which activities to spend the most time on based on their individual needs (based on an online quiz taken the night before the class period, and their personal self-confidence with the material). Available in-class activities and worksheets were developed by the faculty member based on student scores on the online quiz as well as personal messages submitted through the course management system the night before the class meeting. While this placed a significant burden on the faculty member in terms of course preparation, it allowed for just-in-time teaching to take place. This poster describes the results of student mastery of content centered on the sun-earth-moon system (specifically seasons, moon phases, and eclipses) as compared to traditional classroom sections.

  20. Exploring Sun-Earth Connections: A Physical Science Program for (K-8)Teachers (United States)

    Michels, D. J.; Pickert, S. M.; Thompson, J. L.; Montrose, C. J.


    An experimental, inquiry-based physical science curriculum for undergraduate, pre-service K-8 teachers is under development at the Catholic University of America in collaboration with the Solar Physics Branch of the Naval Research Laboratory and NASA's Sun-Earth Connection missions. This is a progress report. The current, stunningly successful exploratory phase in Sun-Earth Connection (SEC) physics, sparked by SOHO, Yohkoh, TRACE, and other International Solar Terrestrial Physics (ISTP) and Living With a Star (LWS) programs, has provided dynamic, visually intuitive data that can be used for teaching basic physical concepts such as the properties of gravitational and electromagnetic fields which are manifest in beautiful imagery of the astrophysical plasmas of the solar atmosphere and Earth's auroras. Through a team approach capitalizing on the combined expertise of the Catholic University's departments of Education and Physics and of NRL solar researchers deeply involved in SEC missions we have laid out a program that will teach non-science-major undergraduates a very limited number of physical science concepts but in such a way as to develop for each one both a formal understanding and an intuitive grasp that will instill confidence, spark interest and scientific curiosity and, ideally, inspire a habit of lifetime inquiry and professional growth. A three-semester sequence is planned. The first semester will be required of incoming Education freshmen. The second and third semesters will be of such a level as to satisfy the one-year science requirement for non-science majors in the College of Arts and Sciences. The approach as adopted will integrate physics content and educational methods, with each concept introduced through inquiry-based, hands-on investigation using methods and materials directly applicable to K-8 teaching situations (Exploration Phase). The topic is further developed through discussion, demonstration and lecture, introducing such mathematical

  1. "Tormenta Espacial" - Exploring The Sun-earth Connection With A Spanish-language Planetarium Show (United States)

    Elteto, Attila; Salas, F.; Duncan, D.; Traub-Metlay, S.


    Reaching out to Spanish speakers is increasingly vital to workforce development and public support of space science projects. Building on a successful partnership with NASA's TIMED mission, LASP and Space Science Institute, Fiske Planetarium has translated its original planetarium show - "Space Storm” - into "Tormenta Espacial". This show explores the Sun-Earth connection and explains how solar activity affects technology and life on Earth. Solar scientists from NOAA's Space Environment Center and the University of Colorado at Boulder contributed to provide scientific accuracy. Show content and accompanying educational materials are aligned with state and national science standards. While designed for students in grades 6-8, this show has been positively evaluated by students from grades 4-10 and shown to the general public with favorable responses. Curricular materials extend the planetarium experience into the K-12 classroom so that students inspired and engaged by the show continue to see real-life applications and workplace opportunities. Fiske Planetarium offers both "Space Storm” and "Tormenta Espacial” to other planetariums at a minimal rate, including technical support for the life of the show. Thanks to a request from a planetarium in Belgium, a version of "Space Storm” is available with no spoken dialogue so that languages other than English or Spanish may be accommodated. Collaborative projects among planetariums, NASA missions (planned as well as active), research scientists and other parties keep EPO activities healthy and well-funded. Fiske Planetarium staff strive to develop and maintain partnerships throughout the EPO and informal education communities.

  2. CAWSES (Climate and Weather of the Sun-Earth System) Science: Progress thus far and the next steps (United States)

    Pallamraju, D.; Kozyra, J.; Basu, S.

    Climate and Weather of the Sun Earth System CAWSES is the current program of Scientific Committee for Solar Terrestrial Physics SCOSTEP for 2004 - 2008 The main aim of CAWSES is to bring together scientists from various nations to address the coupled and global nature of the Sun-Earth System phenomena Towards that end CAWSES provides a platform for international cooperation in observations data analysis theory and modeling There has been active international participation thus far with endorsement of the national CAWSES programs in some countries and many scientists around the globe actively volunteering their time in this effort The CAWSES Science Steering Group has organized the CAWSES program into five Themes for better execution of its science Solar Influence on Climate Space Weather Science and Applications Atmospheric Coupling Processes Space Climatology and Capacity Building and Education CAWSES will cooperate with International programs that focus on the Sun-Earth system science and at the same time compliment the work of programs whose scope is beyond the realm of CAWSES This talk will briefly review the science goals of CAWSES provide salient results from different Themes with emphasis on those from the Space Weather Theme This talk will also indicate the next steps that are being planned in this program and solicit inputs from the community for the science efforts to be carried out in the future

  3. High-Performance Data Analysis Tools for Sun-Earth Connection Missions (United States)

    Messmer, Peter


    The data analysis tool of choice for many Sun-Earth Connection missions is the Interactive Data Language (IDL) by ITT VIS. The increasing amount of data produced by these missions and the increasing complexity of image processing algorithms requires access to higher computing power. Parallel computing is a cost-effective way to increase the speed of computation, but algorithms oftentimes have to be modified to take advantage of parallel systems. Enhancing IDL to work on clusters gives scientists access to increased performance in a familiar programming environment. The goal of this project was to enable IDL applications to benefit from both computing clusters as well as graphics processing units (GPUs) for accelerating data analysis tasks. The tool suite developed in this project enables scientists now to solve demanding data analysis problems in IDL that previously required specialized software, and it allows them to be solved orders of magnitude faster than on conventional PCs. The tool suite consists of three components: (1) TaskDL, a software tool that simplifies the creation and management of task farms, collections of tasks that can be processed independently and require only small amounts of data communication; (2) mpiDL, a tool that allows IDL developers to use the Message Passing Interface (MPI) inside IDL for problems that require large amounts of data to be exchanged among multiple processors; and (3) GPULib, a tool that simplifies the use of GPUs as mathematical coprocessors from within IDL. mpiDL is unique in its support for the full MPI standard and its support of a broad range of MPI implementations. GPULib is unique in enabling users to take advantage of an inexpensive piece of hardware, possibly already installed in their computer, and achieve orders of magnitude faster execution time for numerically complex algorithms. TaskDL enables the simple setup and management of task farms on compute clusters. The products developed in this project have the

  4. Sun-Earth System Interaction studies over Vietnam: an international cooperative project

    Directory of Open Access Journals (Sweden)

    C. Amory-Mazaudier


    Full Text Available During many past decades, scientists from various countries have studied separately the atmospheric motions in the lower atmosphere, in the Earth's magnetic field, in the magnetospheric currents, etc. All of these separate studies lead today to the global study of the Sun and Earth connections, and as a consequence, new scientific programs (IHY- International Heliophysical Year, CAWSES- Climate and Weather in the Sun-Earth System are defined, in order to assume this new challenge. In the past, many scientists did not have the possibility to collect data at the same time in the various latitude and longitude sectors. Now, with the progress of geophysical sciences in many developing countries, it is possible to have access to worldwide data sets. This paper presents the particularities of geophysical parameters measured by the Vietnamese instrument networks. It introduces a cooperative Vietnamese-IGRGEA (International Geophysical Research Group Europe Africa project, and presents, for the first time, to the international community, the geophysical context of Vietnam. Concerning the ionosphere: since 1963, during four solar cycles, the ionosonde at Phu Thuy (North Vietnam was operating. The Phu Thuy data exhibits the common features for the ionospheric parameters, previously observed in other longitude and latitude sectors. The critical frequencies of the E, F1 and F2 ionospheric layers follow the variation of the sunspot cycle. F2 and E critical frequencies also exhibit an annual variation. The first maps of TEC made with data from GPS receivers recently installed in Vietnam illustrate the regional equatorial pattern, i.e. two maxima of electronic density at 15° N and 15° S from the magnetic equator and a trough of density at the magnetic equator. These features illustrate the equatorial fountain effect. Concerning the Earth's magnetic field: a strong amplitude of the equatorial electrojet was first observed by the CHAMP satellite at the height

  5. Unique Non-Keplerian Orbit Vantage Locations for Sun-Earth Connection and Earth Science Vision Roadmaps (United States)

    Folta, David; Young, Corissa; Ross, Adam


    The purpose of this investigation is to determine the feasibility of attaining and maintaining unique non-Keplerian orbit vantage locations in the Earth/Moon environment in order to obtain continuous scientific measurements. The principal difficulty associated with obtaining continuous measurements is the temporal nature of astrodynamics, i.e., classical orbits. This investigation demonstrates advanced trajectory designs to meet demanding science requirements which cannot be met following traditional orbital mechanic logic. Examples of continuous observer missions addressed include Earth pole-sitters and unique vertical libration orbits that address Sun-Earth Connection and Earth Science Vision roadmaps.

  6. The Sun-earth Imbalance radiometer for a direct measurement of the net heating of the earth (United States)

    Dewitte, Steven; Karatekin, Özgür; Chevalier, Andre; Clerbaux, Nicolas; Meftah, Mustapha; Irbah, Abdanour; Delabie, Tjorven


    It is accepted that the climate on earth is changing due to a radiative energy imbalance at the top of the atmosphere, up to now this radiation imbalance has not been measured directly. The measurement is challenging both in terms of space-time sampling of the radiative energy that is leaving the earth and in terms of accuracy. The incoming solar radiation and the outgoing terrestrial radiation are of nearly equal magnitude - of the order of 340 W/m² - resulting in a much smaller difference or imbalance of the order of 1 W/m². The only way to measure the imbalance with sufficient accuracy is to measure both the incoming solar and the outgoing terrestrial radiation with the same instrument. Based on our 30 year experience of measuring the Total Solar Irradiance with the Differential Absolute RADiometer (DIARAD) type of instrument and on our 10 year experience of measuring the Earth Radiation Budget with the Geostationary Earth Radiation Budget (GERB) instrument on Meteosat Second Generation, we propose an innovative constellation of Sun-earth IMBAlance (SIMBA) radiometer cubesats with the ultimate goal to measure the Sun-earth radiation imbalance. A first Simba In Orbit Demonstration satellite is scheduled for flight with QB50 in 2015. It is currently being developed as ESA's first cubesat through an ESA GSTP project. In this paper we will give an overview of the Simba science objectives and of the current satellite and payload development status.

  7. L2 Working Memory Capacity and L2 Reading Skill. (United States)

    Harrington, Mike; Sawyer, Mark


    Examines the sensitivity of second-language (L2) working memory (ability to store and process information simultaneously) to differences in reading skills among advanced L2 learners. Subjects with larger L2 working memory capacities scored higher on measures of L2 reading skills, but no correlation was found between reading and passive short-term…

  8. A small mission concept to the Sun-Earth Lagrangian L5 point for innovative solar, heliospheric and space weather science

    Czech Academy of Sciences Publication Activity Database

    Lavraud, B.; Liu, Y.; Segura, K.; He, J.; Qin, G.; Temmer, M.; Vial, J. C.; Xiong, M.; Davies, J. A.; Rouillard, A. P.; Pinto, R.; Auchere, F.; Harrison, R. A.; Eyles, C.; Gan, W.; Lamy, P.; Xia, L.; Eastwood, J. P.; Kong, L.; Wang, J.; Wimmer-Schweingruber, R. F.; Zhang, S.; Zong, Q.; Souček, Jan; An, J.; Přech, J.; Zhang, A.; Rochus, P.; Bothmer, V.; Janvier, M.; Maksimovic, M.; Escoubet, C. P.; Kilpua, E. K. J.; Tappin, J.; Vainio, R.; Poedts, S.; Dunlop, M. W.; Savani, N.; Gopalswamy, N.; Bale, S. D.; Howard, T.; DeForest, C.; Webb, D.; Lugaz, N.; Fuselier, S. A.; Dalmasse, K.; Tallineau, J.; Vranken, D.; Fernández, J. G.


    Roč. 146, August (2016), s. 171-185 ISSN 1364-6826 R&D Projects: GA ČR(CZ) GA14-31899S; GA MŠk(CZ) LH15304 Institutional support: RVO:68378289 Keywords : space mission * coronal mass ejections * instrumentation * space weather Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.326, year: 2016

  9. Monitoring solar irradiance from L2 with Gaia (United States)

    Serpell, E.


    Gaia is the European Space Agency's cornerstone astrometry mission to measure the positions of a billion stars in the Milky Way with unprecedented accuracy. Since early 2014 Gaia has been operating in a halo orbit around the second Sun-Earth Lagrange point that provides the stable thermal environment, without Earth eclipses, needed for the payload to function accurately. The spacecraft is equipped with a number of thermally isolated, sun-facing thermistors that provide a continuous measurement of the local equilibrium temperature. As a consequence of the spacecraft design and operational conditions these temperature measurements have been used to infer the solar output over a broad wavelength range. In this paper we present an analysis of temperature measurements made of the Gaia solar panels at frequencies of up to 1 Hz for the first 35 months of routine operations. We show that the Gaia solar panel temperature measurements are capable of precisely determining short term changes to the solar output at a level of better than 0.04% with time constants of a few minutes.

  10. L2 listening at work

    DEFF Research Database (Denmark)

    Øhrstrøm, Charlotte

    This dissertation on adult second language (L2) learning investigates individual learners’ experiences with listening in Danish as an L2 in everyday situations at work. More specifically, the study explores when international employees, who work at international companies in Denmark with English...... as a corporate language, listen in Danish at work, how they handle these situations, what problems they experience, and why some situations are more difficult to listen in than others. The study makes use of qualitative research methods and theoretical aspects from psycholinguistic approaches as well as socially...

  11. Design of the stabilizing control of the orbital motion in the vicinity of the collinear libration point L1 using the analytical representation of the invariant manifold (United States)

    Maliavkin, G. P.; Shmyrov, A. S.; Shmyrov, V. A.


    Vicinities of collinear libration points of the Sun-Earth system are currently quite attractive for the space navigation. Today, various projects on placing of spacecrafts observing the Sun in the L1 libration point and telescopes in L2 have been implemented (e.g. spacecrafts "WIND", "SOHO", "Herschel", "Planck"). Collinear libration points being unstable leads to the problem of stabilization of a spacecraft's motion. Laws of stabilizing motion control in vicinity of L1 point can be constructed using the analytical representation of a stable invariant manifold. Efficiency of these control laws depends on the precision of the representation. Within the model of Hill's approximation of the circular restricted three-body problem in the rotating geocentric coordinate system one can obtain the analytical representation of an invariant manifold filled with bounded trajectories in a form of series in terms of powers of the phase variables. Approximate representations of the orders from the first to the fourth inclusive can be used to construct four laws of stabilizing feedback motion control under which trajectories approach the manifold. By virtue of numerical simulation the comparison can be made: how the precision of the representation of the invariant manifold influences the efficiency of the control, expressed by energy consumptions (characteristic velocity). It shows that using approximations of higher orders in constructing the control laws can significantly reduce the energy consumptions on implementing the control compared to the linear approximation.

  12. L2 Selves, Emotions, and Motivated Behaviors (United States)

    Teimouri, Yasser


    This study has aimed to investigate language learners' emotional experiences through the lens of L2 future self-guides. To that end, the L2 motivational self system was chosen as the theoretical framework to relate learners' emotions to their L2 selves. However, due to inconsistent results of past research concerning the motivational role of the…

  13. Measurements of Development in L2 Written Production: The Case of L2 Chinese (United States)

    Jiang, Wenying


    This study investigates measures for second language (L2) writing development. A T-unit, which has been found the most satisfactory unit of analysis for measuring L2 development in English, is extended to measure L2 Chinese writing development through a cross-sectional design in this study. Data were collected from three L2 Chinese learner groups…

  14. Statistical analysis of solar events associated with SSC over year of solar maximum during cycle 23: 2. Characterisation on the Sun-Earth path - Geoeffectiveness (United States)

    Cornilleau-Wehrlin, N.; Bocchialini, K.; Menvielle, M.; Fontaine, D.; Grison, B.; Marchaudon, A.; Pick, M.; Pitout, F.; Schmieder, B.; Regnier, S.; Zouganelis, Y.; Chambodut, A.


    Taking the 32 sudden storm commencements (SSC) listed by the observatory de l'Ebre / ISGI over the year 2002 (maximal solar activity) as a starting point, we performed a statistical analysis of the related solar sources, solar wind signatures, and terrestrial responses. For each event, we characterized and identified, as far as possible, (i) the sources on the Sun (Coronal Mass Ejections -CME-), with the help of a series of criteria (velocities, drag coefficient, radio waves, magnetic field polarity), as well as (ii) the structure and properties in the interplanetary medium, at L1, of the event associated to the SSC: magnetic clouds -MC-, non-MC interplanetary coronal mass ejections -ICME-, co-rotating/stream interaction regions -SIR/CIR-, shocks only and unclear events that we call "miscellaneous" events. The geoeffectiveness of the events, classified by category at L1, is analysed by their signatures in the Earth ionized (magnetosphere and ionosphere) and neutral (thermosphere) environments, using a broad set of in situ, remote and ground based instrumentation. The role of the presence of a unique or of a multiple source at the Sun, of its nature, halo or non halo CME, is also discussed. The set of observations is statistically analyzed so as to evaluate and compare the geoeffectiveness of the events. The results obtained for this set of geomagnetic storms started by SSCs is compared to the overall statistics of year 2002, relying on already published catalogues of events, allowing assessing the relevance of our approach ; for instance all the 12 well identified Magnetic Clouds of 2002 give rise to SSCs.

  15. Statistical Analysis of Solar Events Associated with SSC over Year of Solar Maximum during Cycle 23: 1. Identification of Related Sun-Earth Events (United States)

    Grison, B.; Bocchialini, K.; Menvielle, M.; Chambodut, A.; Cornilleau-Wehrlin, N.; Fontaine, D.; Marchaudon, A.; Pick, M.; Pitout, F.; Schmieder, B.; Regnier, S.; Zouganelis, Y.


    Taking the 32 sudden storm commencements (SSC) listed by the observatory de l'Ebre / ISGI over the year 2002 (maximal solar activity) as a starting point, we performed a statistical analysis of the related solar sources, solar wind signatures, and terrestrial responses. For each event, we characterized and identified, as far as possible, (i) the sources on the Sun (Coronal Mass Ejections -CME-), with the help of a series of herafter detailed criteria (velocities, drag coefficient, radio waves, polarity), as well as (ii) the structure and properties in the interplanetary medium, at L1, of the event associated to the SSC: magnetic clouds -MC-, non-MC interplanetary coronal mass ejections -ICME-, co-rotating/stream interaction regions -SIR/CIR-, shocks only and unclear events that we call "miscellaneous" events. The categorization of the events at L1 is made on published catalogues. For each potential CME/L1 event association we compare the velocity observed at L1 with the one observed at the Sun and the estimated balistic velocity. Observations of radio emissions (Type II, Type IV detected from the ground and /or by WIND) associated to the CMEs make the solar source more probable. We also compare the polarity of the magnetic clouds with the hemisphere of the solar source. The drag coefficient (estimated with the drag-based model) is calculated for each potential association and it is compared to the expected range values. We identified a solar source for 26 SSC related events. 12 of these 26 associations match all criteria. We finally discuss the difficulty to perform such associations.

  16. The L2 Motivational Self System and L2 Achievement: A Study of Saudi EFL Learners (United States)

    Moskovsky, Christo; Assulaimani, Turki; Racheva, Silvia; Harkins, Jean


    The research reported in this article explores the relationship between Dörnyei's (2005, 2009) Second Language Motivational Self System (L2MSS) and the L2 proficiency level of Saudi learners of English as a foreign language (EFL). Male and female participants (N = 360) responded to a questionnaire relating to the main components of L2MSS, the…

  17. L2 Quality as a Competitive Edge - Project Presentation

    DEFF Research Database (Denmark)

    Ditlevsen, Marianne Grove; Kastberg, Peter


    In our paper we would like to present an interdisciplinary project "L2 as a Competitive Edge". We'll be doing this by first giving you a project overview in section 0. The overview will then in the section 1 and 2 be followed by a presentation of two of the most interesting themes, serving as point...... of departure for further discussion. The two themes are "The evaluation of language quality" and "Method - an Integrated Approach"....

  18. Lexical representation of novel L2 contrasts (United States)

    Hayes-Harb, Rachel; Masuda, Kyoko


    There is much interest among psychologists and linguists in the influence of the native language sound system on the acquisition of second languages (Best, 1995; Flege, 1995). Most studies of second language (L2) speech focus on how learners perceive and produce L2 sounds, but we know of only two that have considered how novel sound contrasts are encoded in learners' lexical representations of L2 words (Pallier et al., 2001; Ota et al., 2002). In this study we investigated how native speakers of English encode Japanese consonant quantity contrasts in their developing Japanese lexicons at different stages of acquisition (Japanese contrasts singleton versus geminate consonants but English does not). Monolingual English speakers, native English speakers learning Japanese for one year, and native speakers of Japanese were taught a set of Japanese nonwords containing singleton and geminate consonants. Subjects then performed memory tasks eliciting perception and production data to determine whether they encoded the Japanese consonant quantity contrast lexically. Overall accuracy in these tasks was a function of Japanese language experience, and acoustic analysis of the production data revealed non-native-like patterns of differentiation of singleton and geminate consonants among the L2 learners of Japanese. Implications for theories of L2 speech are discussed.

  19. Suggestions of keeping L2 motivation

    Institute of Scientific and Technical Information of China (English)



    How will we keep the motivation during the second language as long as we can, which confuses us, though what the L2 motivation is and how it is developed have been discussed by the psychologists, educators, etc. The aim of this passage is to clarify the basic content of motivation, including the definition, classification, importance, etc. how the current situation is in se-nior high students’English learning motivation, what should be done to keep such motivation. In the following part, it will be read that the introduction, the chapter stating the content and classification of (L 2) motivation, the chapter analyzing the necessity and state of L2 motivation at senor high, the chapter offering approach to keep that motivation, and the conclusion. All of them use the comparison, explanation and cites.

  20. L2 writing and L2 written feedback in upper secondary schools as experienced by teachers


    Manousou, Angeliki


    L2 written feedback is a multi-faceted issue and this is the reason behind the big number of studies that have been conducted on it. However, the majority of studies deal with learners’ opinions of teachers’ feedback or several types of feedback and their advantages and disadvantages. There are no studies that could have addressed teachers’ opinions of their L2 written feedback. This study attempts to describe how L2 teachers view their written feedback on learners’ essays. ...

  1. L2 Chinese: Grammatical Development and Processing (United States)

    Mai, Ziyin


    Two recent books (Jiang, 2014, "Advances in Chinese as a second language"; Wang, 2013, "Grammatical development of Chinese among non-native speakers") provide new resources for exploring the role of processing in acquiring Chinese as a second language (L2). This review article summarizes, assesses and compares some of the…

  2. Investigating L2 Performance in Text Chat (United States)

    Sauro, Shannon; Smith, Bryan


    This study examines the linguistic complexity and lexical diversity of both overt and covert L2 output produced during synchronous written computer-mediated communication, also referred to as chat. Video enhanced chatscripts produced by university learners of German (N = 23) engaged in dyadic task-based chat interaction were coded and analyzed for…

  3. A Brief Analysis of L2 Motivation

    Institute of Scientific and Technical Information of China (English)



    Learning motivation is the motility to urge the student to be engaged in the studies activity. This thesis has introduced types of L2 learning motivation. Through the contrast and analysis about the positive motivation and negative motivation in prac?tical applications, this paper has indicated the unique of positive motivation and the defects of negative motivation, and make rea?sonable suggestions.

  4. MD2725: 16L2 aperture measurement

    CERN Document Server

    Mirarchi, Daniele; Rossi, Roberto; CERN. Geneva. ATS Department


    Dumps induced by sudden increase of losses in the half-cell 16L2 have been a serious machine limitation during the 2017 run. The aim of this MD was to perform local aperture measurements in order to assess differences after the beam screen regeneration, compared to first measurements in 2017.

  5. Comparing L1 and L2 Texts and Writers in First-Year Composition (United States)

    Eckstein, Grant; Ferris, Dana


    Scholars have at various points discussed the needs of second language (L2) writers enrolled in "mainstream" composition courses where they are mixed with native (L1) English speakers. Other researchers have investigated the experiences of L2 writers in mainstream classes and the perceptions of their instructors about their abilities and…

  6. Russian Speakers' L2 Chinese Acquisition of "Wh"-Topicalization at the Syntax-Discourse Interface (United States)

    Dugarova, Esuna


    In recent second language (L2) research it has been proposed that unlike linguistic phenomena pertaining to internal interfaces, those at external interfaces pose greater difficulty to adult L2 learners and may not be fully acquired. It has further been pointed out that such problematic acquisition at the interface level should not be attributed…


    Directory of Open Access Journals (Sweden)

    Elisabetta Jafrancesco


    analyzed the use of SD in the spoken dialogue between students at the basic, independent and competent CEFR levels, with reference to the taxonomic SD model proposed by Bazzanella in the Grande grammatica italiana di consultazione (1995. In relation to the specific context, we integrated new features, focusing on key macro-phenomena that emerged, with the intention of considering how L2 data acquisition can be a reference point for the definition of training consistent with the natural processes of competence development.

  8. Gaming as Extramural English L2 Learning and L2 Proficiency among Young Learners (United States)

    Sylven, Liss Kerstin; Sundqvist, Pia


    Today, playing digital games is an important part of many young people's everyday lives. Claims have been made that certain games, in particular massively multiplayer online role-playing games (MMORPGs) provide L2 English learners with a linguistically rich and cognitively challenging virtual environment that may be conducive to L2 learning, as…

  9. The Impact of Resilience on L2 Learners' Motivated Behaviour and Proficiency in L2 Learning (United States)

    Kim, Tae-Young; Kim, Yoon-Kyoung


    This exploratory study focused on the factors that constitute second language (L2) learners' resilience, and how these factors are related to L2 learning by investigating what relation resilience may have to motivated behaviour and proficiency in English learning. A total of 1620 secondary school learners of English participated in a questionnaire…

  10. Development and implementation of a novel assay for L-2-hydroxyglutarate dehydrogenase (L-2-HGDH) in cell lysates: L-2-HGDH deficiency in 15 patients with L-2-hydroxyglutaric aciduria

    DEFF Research Database (Denmark)

    Kranendijk, M; Salomons, G S; Gibson, K M


    L-2-hydroxyglutaric aciduria (L-2-HGA) is a rare inherited autosomal recessive neurometabolic disorder caused by mutations in the gene encoding L-2-hydroxyglutarate dehydrogenase. An assay to evaluate L-2-hydroxyglutarate dehydrogenase (L-2-HGDH) activity in fibroblast, lymphoblast and/or lymphoc...


    Directory of Open Access Journals (Sweden)

    Tom Cobb


    Full Text Available Linguistic computing can make two important contributions to second language (L2 reading instruction. One is to resolve longstanding research issues that are based on an insufficiency of data for the researcher, and the other is to resolve related pedagogical problems based on insufficiency of input for the learner. The research section of the paper addresses the question of whether reading alone can give learners enough vocabulary to read. When the computer’s ability to process large amounts of both learner and linguistic data is applied to this question, it becomes clear that, for the vast majority of L2 learners, free or wide reading alone is not a sufficient source of vocabulary knowledge for reading. But computer processing also points to solutions to this problem. Through its ability to reorganize and link documents, the networked computer can increase the supply of vocabulary input that is available to the learner. The development section of the paper elaborates a principled role for computing in L2 reading pedagogy, with examples, in two broad areas, computer-based text design and computational enrichment of undesigned texts.

  12. ASTER L2 Surface Reflectance SWIR and ASTER L2 Surface Reflectance VNIR V003 (United States)

    National Aeronautics and Space Administration — The ASTER L2 Surface Reflectance is a multi-file product that contains atmospherically corrected data for both the Visible Near-Infrared (VNIR) and Shortwave...

  13. Immunogenicity of an HPV-16 L2 DNA vaccine (United States)

    Hitzeroth, Inga I.; Passmore, Jo-Ann S.; Shephard, Enid; Stewart, Debbie; Müller, Martin; Williamson, Anna-Lise; Rybicki, Edward P.; Kast, W. Martin


    The ability to elicit cross-neutralizing antibodies makes human papillomavirus (HPV) L2 capsid protein a possible HPV vaccine. We examined and compared the humoral response of mice immunised with a HPV-16 L2 DNA vaccine or with HPV-16 L2 protein. The L2 DNA vaccine elicited a non-neutralising antibody response unlike the L2 protein. L2 DNA vaccination suppressed the growth of L2-expressing C3 tumor cells, which is a T cell mediated effect, demonstrating that the lack of non-neutralizing antibody induction by L2 DNA was not caused by lack of T cell immunogenicity of the construct. PMID:19559114

  14. Orthogonal Multiwavelet Frames in L2Rd

    Directory of Open Access Journals (Sweden)

    Liu Zhanwei


    Full Text Available We characterize the orthogonal frames and orthogonal multiwavelet frames in L2Rd with matrix dilations of the form (Df(x=detAf(Ax, where A is an arbitrary expanding d×d matrix with integer coefficients. Firstly, through two arbitrarily multiwavelet frames, we give a simple construction of a pair of orthogonal multiwavelet frames. Then, by using the unitary extension principle, we present an algorithm for the construction of arbitrarily many orthogonal multiwavelet tight frames. Finally, we give a general construction algorithm for orthogonal multiwavelet tight frames from a scaling function.

  15. ECR heating in L-2M stellarator

    International Nuclear Information System (INIS)

    Grebenshchikov, S.E.; Batanov, G.M.; Fedyanin, O.I.


    The first results of ECH experiments in the L-2M stellarator are presented. The main goal of the experiments is to investigate the physics of ECH and plasma confinement at very high values of the volume heating power density. A current free plasma is produced and heated by extraordinary waves at the second harmonic of the electron cyclotron frequency. The experimental results are compared with the numerical simulations of plasma confinement and heating processes based on neoclassical theory using the full matrix of transport coefficients and with LHD-scaling. 4 refs., 2 figs

  16. Negative evidence in L2 acquisition

    Directory of Open Access Journals (Sweden)

    Anne Dahl


    Full Text Available This article deals with the L2 acquisition of differences between Norwegian and English passives, and presents data to show that the acquisition of these differences by Norwegian L2 acquirers of English cannot be fully explained by positive evidence, cues, conservativism or economy. Rather, it is argued, it is natural to consider whether indirect negative evidence may facilitate acquisition by inferencing. The structures in focus are impersonal passive constructions with postverbal NPs and passive constructions with intransitive verbs. These sentences are ungrammatical in English. Chomsky (1981 proposes that this is a result of passive morphology absorbing objective case in English. There is no such case to be assigned to the postverbal NP in impersonal passives. In passive constructions with intransitive verbs, the verb does not assign objective case, so that there is no case for the passive morphology to absorb. Thus, impersonal passives have to be changed into personal passives, where the NP receives nominative case, and the objective case is free to go to the passive morphology. Intransitive verbs, however, cannot be used in the passive voice at all. Both the structures discussed in this article, i.e. are grammatical in Norwegian. However, the options available in English, viz. personal passives and active sentences, are equally possible. Åfarli (1992 therefore proposes that Norwegian has optional case absorption (passive morphology optionally absorbs case. On the basis on such observations, we may propose a parameter with the settings [+case absorption] for English, and [-case absorption], signifying optional case absorption, for Norwegian. This means that none of the structures that are grammatical in English can function as positive evidence for the [+case absorption] setting, since they are also grammatical in optional case absorption languages. The question is how this parameter is set.

  17. The Relationship between Three Measures of L2 Vocabulary Knowledge and L2 Listening and Reading (United States)

    Cheng, Junyu; Matthews, Joshua


    This study explores the constructs that underpin three different measures of vocabulary knowledge and investigates the degree to which these three measures correlate with, and are able to predict, measures of second language (L2) listening and reading. Word frequency structured vocabulary tests tapping "receptive/orthographic (RecOrth)…

  18. Low Parametric Sensitivity Realizations with relaxed L2-dynamic-range-scaling constraints


    Hilaire , Thibault


    This paper presents a new dynamic-range scaling for the implementation of filters/controllers in state-space form. Relaxing the classical L2-scaling constraints by specific fixed-point considerations allows for a higher degree of freedom for the optimal L2-parametric sensitivity problem. However, overflows in the implementation are still prevented. The underlying constrained problem is converted into an unconstrained problem for which a solution can be provided. This leads to realizations whi...

  19. ASC Trilab L2 Codesign Milestone 2015

    Energy Technology Data Exchange (ETDEWEB)

    Trott, Christian Robert [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hammond, Simon David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Dinge, Dennis [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lin, Paul T. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Vaughan, Courtenay T. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Cook, Jeanine [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Edwards, Harold C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rajan, Mahesh [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hoekstra, Robert J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)


    For the FY15 ASC L2 Trilab Codesign milestone Sandia National Laboratories performed two main studies. The first study investigated three topics (performance, cross-platform portability and programmer productivity) when using OpenMP directives and the RAJA and Kokkos programming models available from LLNL and SNL respectively. The focus of this first study was the LULESH mini-application developed and maintained by LLNL. In the coming sections of the report the reader will find performance comparisons (and a demonstration of portability) for a variety of mini-application implementations produced during this study with varying levels of optimization. Of note is that the implementations utilized including optimizations across a number of programming models to help ensure claims that Kokkos can provide native-class application performance are valid. The second study performed during FY15 is a performance assessment of the MiniAero mini-application developed by Sandia. This mini-application was developed by the SIERRA Thermal-Fluid team at Sandia for the purposes of learning the Kokkos programming model and so is available in only a single implementation. For this report we studied its performance and scaling on a number of machines with the intent of providing insight into potential performance issues that may be experienced when similar algorithms are deployed on the forthcoming Trinity ASC ATS platform.

  20. L2, the minor capsid protein of papillomavirus

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Joshua W. [Department of Pathology, The Johns Hopkins University, Baltimore, MD 21287 (United States); Roden, Richard B.S., E-mail: [Department of Pathology, The Johns Hopkins University, Baltimore, MD 21287 (United States); Department of Oncology, The Johns Hopkins University, Baltimore, MD 21287 (United States); Department of Gynecology and Obstetrics, The Johns Hopkins University, Baltimore, MD 21287 (United States)


    The capsid protein L2 plays major roles in both papillomavirus assembly and the infectious process. While L1 forms the majority of the capsid and can self-assemble into empty virus-like particles (VLPs), L2 is a minor capsid component and lacks the capacity to form VLPs. However, L2 co-assembles with L1 into VLPs, enhancing their assembly. L2 also facilitates encapsidation of the ∼8 kbp circular and nucleosome-bound viral genome during assembly of the non-enveloped T=7d virions in the nucleus of terminally differentiated epithelial cells, although, like L1, L2 is not detectably expressed in infected basal cells. With respect to infection, L2 is not required for particles to bind to and enter cells. However L2 must be cleaved by furin for endosome escape. L2 then travels with the viral genome to the nucleus, wherein it accumulates at ND-10 domains. Here, we provide an overview of the biology of L2. - Highlights: • L2 is the minor antigen of the non-enveloped T=7d icosahedral Papillomavirus capsid. • L2 is a nuclear protein that can traffic to ND-10 and facilitate genome encapsidation. • L2 is critical for infection and must be cleaved by furin. • L2 is a broadly protective vaccine antigen recognized by neutralizing antibodies.

  1. L2, the minor capsid protein of papillomavirus

    International Nuclear Information System (INIS)

    Wang, Joshua W.; Roden, Richard B.S.


    The capsid protein L2 plays major roles in both papillomavirus assembly and the infectious process. While L1 forms the majority of the capsid and can self-assemble into empty virus-like particles (VLPs), L2 is a minor capsid component and lacks the capacity to form VLPs. However, L2 co-assembles with L1 into VLPs, enhancing their assembly. L2 also facilitates encapsidation of the ∼8 kbp circular and nucleosome-bound viral genome during assembly of the non-enveloped T=7d virions in the nucleus of terminally differentiated epithelial cells, although, like L1, L2 is not detectably expressed in infected basal cells. With respect to infection, L2 is not required for particles to bind to and enter cells. However L2 must be cleaved by furin for endosome escape. L2 then travels with the viral genome to the nucleus, wherein it accumulates at ND-10 domains. Here, we provide an overview of the biology of L2. - Highlights: • L2 is the minor antigen of the non-enveloped T=7d icosahedral Papillomavirus capsid. • L2 is a nuclear protein that can traffic to ND-10 and facilitate genome encapsidation. • L2 is critical for infection and must be cleaved by furin. • L2 is a broadly protective vaccine antigen recognized by neutralizing antibodies

  2. L2TTMON Monitoring Program for L2 Topological Trigger in H1 Experiment - User's Guide

    International Nuclear Information System (INIS)

    Banas, E.; Ducorps, A.


    Monitoring software for the L2 Topological Trigger in H1 experiment consists of two parts working on two different computers. The hardware read-out and data processing is done on a fast FIC 8234 computer working with the OS9 real time operating system. The Macintosh Quadra is used as a Graphic User Interface for accessing the OS9 trigger monitoring software. The communication between both computers is based on the parallel connection between the Macintosh and the VME crate, where the FIC computer is placed. The special designed protocol (client-server) is used to communicate between both nodes. The general scheme of monitoring for the L2 Topological Trigger and detailed description of using of the monitoring software in both nodes are given in this guide. (author)

  3. Evaluating Bilingual and Monolingual Dictionaries for L2 Learners. (United States)

    Hunt, Alan


    A discussion of dictionaries and their use for second language (L2) learning suggests that lack of computerized modern language corpora can adversely affect bilingual dictionaries, commonly used by L2 learners, and shows how use of such corpora has benefitted two contemporary monolingual L2 learner dictionaries (1995 editions of the Longman…

  4. An overview of L-2-hydroxyglutarate dehydrogenase gene (L2HGDH) variants: a genotype-phenotype study

    DEFF Research Database (Denmark)

    Steenweg, Marjan E; Jakobs, Cornelis; Errami, Abdellatif


    L-2-Hydroxyglutaric aciduria (L2HGA) is a rare, neurometabolic disorder with an autosomal recessive mode of inheritance. Affected individuals only have neurological manifestations, including psychomotor retardation, cerebellar ataxia, and more variably macrocephaly, or epilepsy. The diagnosis of ...

  5. Shrinkage Degree in $L_{2}$ -Rescale Boosting for Regression. (United States)

    Xu, Lin; Lin, Shaobo; Wang, Yao; Xu, Zongben


    L 2 -rescale boosting ( L 2 -RBoosting) is a variant of L 2 -Boosting, which can essentially improve the generalization performance of L 2 -Boosting. The key feature of L 2 -RBoosting lies in introducing a shrinkage degree to rescale the ensemble estimate in each iteration. Thus, the shrinkage degree determines the performance of L 2 -RBoosting. The aim of this paper is to develop a concrete analysis concerning how to determine the shrinkage degree in L 2 -RBoosting. We propose two feasible ways to select the shrinkage degree. The first one is to parameterize the shrinkage degree and the other one is to develop a data-driven approach. After rigorously analyzing the importance of the shrinkage degree in L 2 -RBoosting, we compare the pros and cons of the proposed methods. We find that although these approaches can reach the same learning rates, the structure of the final estimator of the parameterized approach is better, which sometimes yields a better generalization capability when the number of sample is finite. With this, we recommend to parameterize the shrinkage degree of L 2 -RBoosting. We also present an adaptive parameter-selection strategy for shrinkage degree and verify its feasibility through both theoretical analysis and numerical verification. The obtained results enhance the understanding of L 2 -RBoosting and give guidance on how to use it for regression tasks.

  6. An interesting case of metabolic dystonia: L-2 hydroxyglutaric aciduria

    Directory of Open Access Journals (Sweden)

    Padma Balaji


    Full Text Available L-2-hydroxyglutaric aciduria (L-2-HGA, a neurometabolic disorder caused by mutations in the L-2 hydroxyglutarate dehydrogenase (L-2-HGDH gene, presents with psychomotor retardation, cerebellar ataxia, extrapyramidal symptoms, macrocephaly and seizures. Characteristic magnetic resonance imaging findings include subcortical cerebral white matter abnormalities with T2 hyperintensities of the dentate nucleus, globus pallidus, putamen and caudate nucleus. The diagnosis can be confirmed by elevated urinary L-2 hydroxyglutaric acid and mutational analysis of the L-2-HGDH gene. We report two siblings with dystonia diagnosed by classical neuroimaging findings with elevated urinary 2 hydroxyglutaric acid. Riboflavin therapy has shown promising results in a subset of cases, thus highlighting the importance of making the diagnosis in these patients.

  7. Orbital Maneuvers for Spacecrafts Travelling to/from the Lagrangian Points (United States)

    Bertachini, A.

    The well-known Lagrangian points that appear in the planar restricted three-body problem (Szebehely, 1967) are very important for astronautical applications. They are five points of equilibrium in the equations of motion, what means that a particle located at one of those points with zero velocity will remain there indefinitely. The collinear points (L1, L2 and L3) are always unstable and the triangular points (L4 and L5) are stable in the present case studied (Sun-Earth system). They are all very good points to locate a space-station, since they require a small amount of V (and fuel), the control to be used for station-keeping. The triangular points are specially good for this purpose, since they are stable equilibrium points. In this paper, the planar restricted three-body problem is regularized (using Lemaître regularization) and combined with numerical integration and gradient methods to solve the two point boundary value problem (the Lambert's three-body problem). This combination is applied to the search of families of transfer orbits between the Lagrangian points and the Earth, in the Sun-Earth system, with the minimum possible cost of the control used. So, the final goal of this paper is to find the magnitude and direction of the two impulses to be applied in the spacecraft to complete the transfer: the first one when leaving/arriving at the Lagrangian point and the second one when arriving/living at the Earth. This paper is a continuation of two previous papers that studied transfers in the Earth-Moon system: Broucke (1979), that studied transfer orbits between the Lagrangian points and the Moon and Prado (1996), that studied transfer orbits between the Lagrangian points and the Earth. So, the equations of motion are: whereis the pseudo-potential given by: To solve the TPBVP in the regularized variables the following steps are used: i) Guess a initial velocity Vi, so together with the initial prescribed position ri the complete initial state is known; ii

  8. L-2-Hydroxyglutaric aciduria: MRI in seven cases

    Energy Technology Data Exchange (ETDEWEB)

    D`Incerti, L.; Farina, L.; Savoiardo, M. [Dept. of Neuroradiology, Istituto Nazionale Neurologico ``C. Besta``, Milan (Italy); Moroni, I.; Uziel, G. [Dept. of Child Neurology, Istituto Nazionale Neurologico ``C. Besta``, Milan (Italy)


    The MRI findings in 7 patients with L-2-Hydroxyglutaric aciduria (L-2-OHG aciduria) are described and compared with previous neuroradiological reports and the only three published pathological cases. Signal abnormalities involved peripheral subcortical white matter, basal ganglia and dentate nuclei. Cerebellar atrophy was present. Although similar appearances may be seen in other metabolic disorders, the distribution of signal abnormalities in L-2-OHG aciduria is highly characteristic and may suggest the correct diagnosis. (orig.) With 5 figs., 2 tabs., 24 refs.

  9. Help Options for L2 Listening in CALL: A Research Agenda (United States)

    Cross, Jeremy


    In this article, I present an agenda for researching help options for second language (L2) listening in computer-assisted language learning (CALL) environments. I outline several theories which researchers in the area draw on, then present common points of concern identified from a review of related literature. This serves as a means to…

  10. Event-related brain potentials and second language learning: syntactic processing in late L2 learners at different L2 proficiency levels

    NARCIS (Netherlands)

    Hell, J.G. van; Tokowicz, N.


    There are several major questions in the literature on late second language (L2) learning and processing. Some of these questions include: Can late L2 learners process an L2 in a native-like way? What is the nature of the differences in L2 processing among L2 learners at different levels of L2

  11. Identification of a new DPY19L2 mutation and a better definition of DPY19L2 deletion breakpoints leading to globozoospermia. (United States)

    Ghédir, Houda; Ibala-Romdhane, Samira; Okutman, Ozlem; Viot, Géraldine; Saad, Ali; Viville, Stéphane


    The purpose of this study was to analyze DPY19L2 sequence variants to investigate the mechanism leading to the entire DPY19L2 deletion in a large cohort of infertile globozoospermic patients. An improved analysis of the DPY19L2 deletion breakpoints (BPs) allowed us to identify two BPs located in a small 1 kb region and to more precisely localize the BPs reported previously. Three genes [spermatogenesis associated 16 (SPATA16), protein interacting with PRKCA (PICK1) and DPY19L2] were previously correlated with globozoospermia, but a homozygous deletion of the entire DPY19L2 was identified as the most frequent alteration causing this phenotype. In addition, several point mutations in this gene were reported. In previous work, we have identified nine BPs for the DPY19L2 deletion clustered in two hotspot regions, while others reported a total of five BPs. We screened for the DPY19L2 deletion and for mutations in the DPY19L2, SPATA16 and PICK1 genes in a cohort of 21 Tunisian globozoospermic patients. In order to characterize the DPY19L2 deletion BPs, we sequenced a 2 kb fragment on low copy repeat (LCR) 1 and LCR2 in Tunisian fertile controls to distinguish between single-nucleotide polymorphisms (SNPs) and LCR-specific markers. Molecular analyses performed on 18 genetically independent individuals showed that 11 (61.1%) were homozygous for the DPY19L2 deletion, 2 (11.1%) were homozygous for the non-synonymous mutation (p.R298C) in exon 8, 1 patient (5.6%) was homozygous for a new splice-site mutation at the junction exon-intron 16 [c.1579_1580+4delAGGTAAinsTCAT] and no DPY19L2, SPATA16 or PICK1 mutations were identified for 4 patients (22.2%). By defining 15 specific LCR markers, we characterized 2 BPs for the DPY19L2 deletion in 11 patients showing the homozygous deletion. Using 20 non-LCR-specific SNPs, we identified 8 distinct haplotypes. A limitation of this study is the small number of patients owing to the rarity of this form of male infertility. Our data showed

  12. Design Issues and Inference in Experimental L2 Research (United States)

    Hudson, Thom; Llosa, Lorena


    Explicit attention to research design issues is essential in experimental second language (L2) research. Too often, however, such careful attention is not paid. This article examines some of the issues surrounding experimental L2 research and its relationships to causal inferences. It discusses the place of research questions and hypotheses,…

  13. Discussion: How different can perspectives on L2 development be?

    NARCIS (Netherlands)

    Hulstijn, J.H.


    In this article I discuss the contributions to this special issue of Language Learning on orders and sequences in second language (L2) development. Using a list of questions, I attempt to characterize what I see as the strengths, limitations, and unresolved issues in the approaches to L2 development

  14. The Effects of L2 Experience on L3 Perception (United States)

    Onishi, Hiromi


    This study examines the influence of experience with a second language (L2) on the perception of phonological contrasts in a third language (L3). This study contributes to L3 phonology by examining the influence of L2 phonological perception abilities on the perception of an L3 at the beginner level. Participants were native speakers of Korean…

  15. Learning and Teaching L2 Collocations: Insights from Research (United States)

    Szudarski, Pawel


    The aim of this article is to present and summarize the main research findings in the area of learning and teaching second language (L2) collocations. Being a large part of naturally occurring language, collocations and other types of multiword units (e.g., idioms, phrasal verbs, lexical bundles) have been identified as important aspects of L2

  16. On the L2-metric of vortex moduli spaces

    NARCIS (Netherlands)

    Baptista, J.M.


    We derive general expressions for the Kähler form of the L2-metric in terms of standard 2-forms on vortex moduli spaces. In the case of abelian vortices in gauged linear sigma-models, this allows us to compute explicitly the Kähler class of the L2-metric. As an application we compute the total

  17. Vocabulary Acquisition in L2: Does CALL Really Help? (United States)

    Averianova, Irina


    Language competence in various communicative activities in L2 largely depends on the learners' size of vocabulary. The target vocabulary of adult L2 learners should be between 2,000 high frequency words (a critical threshold) and 10,000 word families (for comprehension of university texts). For a TOEIC test, the threshold is estimated to be…

  18. Neural changes underlying early stages of L2 vocabulary acquisition. (United States)

    Pu, He; Holcomb, Phillip J; Midgley, Katherine J


    Research has shown neural changes following second language (L2) acquisition after weeks or months of instruction. But are such changes detectable even earlier than previously shown? The present study examines the electrophysiological changes underlying the earliest stages of second language vocabulary acquisition by recording event-related potentials (ERPs) within the first week of learning. Adult native English speakers with no previous Spanish experience completed less than four hours of Spanish vocabulary training, with pre- and post-training ERPs recorded to a backward translation task. Results indicate that beginning L2 learners show rapid neural changes following learning, manifested in changes to the N400 - an ERP component sensitive to lexicosemantic processing and degree of L2 proficiency. Specifically, learners in early stages of L2 acquisition show growth in N400 amplitude to L2 words following learning as well as a backward translation N400 priming effect that was absent pre-training. These results were shown within days of minimal L2 training, suggesting that the neural changes captured during adult second language acquisition are more rapid than previously shown. Such findings are consistent with models of early stages of bilingualism in adult learners of L2 ( e.g. Kroll and Stewart's RHM) and reinforce the use of ERP measures to assess L2 learning.

  19. L2 learner age from a contextualised perspective

    Directory of Open Access Journals (Sweden)

    Jelena Mihaljeviđ Djigunoviđ


    Full Text Available In this qualitative study the author focuses on age effects on young learners’ L2 development by comparing the L2 learning processes of six young learners in an instructed setting: three who had started learning English as L2 at age 6/7 and three who had started at age 9/10. Both earlier and later young beginners were followed for three years (during their second, third and fourth year of learning English. The participants’ L2 development was measured through their oral output elicited by a two-part speaking task administered each year. Results of the analyses are interpreted taking into account each learners’ individual characteristics (learning ability, attitudes and motivation, self-concept and the characteristics of the context in which they were learning their L2 (attitudes of school staff and parents to early L2 learning, home support, in-class and out-of-class exposure to L2, socio-economic status. The findings show that earlier and later young beginners follow different trajectories in their L2 learning, which reflects different interactions which age enters into with the other variables.

  20. Controller synthesis for L2 behaviors using rational kernel representations

    NARCIS (Netherlands)

    Mutsaers, M.E.C.; Weiland, S.


    This paper considers the controller synthesis problem for the class of linear time-invariant L2 behaviors. We introduce classes of LTI L2 systems whose behavior can be represented as the kernel of a rational operator. Given a plant and a controlled system in this class, an algorithm is developed

  1. Slow Epidemic of Lymphogranuloma Venereum L2b Strain (United States)

    Spaargaren, Joke; Schachter, Julius; Moncada, Jeanne; de Vries, Henry J.C.; Fennema, Han S.A.; Peña, A. Salvador; Coutinho, Roel A.


    We traced the Chlamydia trachomatis L2b variant in Amsterdam and San Francisco. All recent lymphogranuloma venereum cases in Amsterdam were caused by the L2b variant. This variant was also present in the 1980s in San Francisco. Thus, the current "outbreak" is most likely a slowly evolving epidemic. PMID:16318741

  2. Speaking L2 in EFL Classes: Performance, Identity and Alterity (United States)

    Forman, Ross


    When teachers and students use L2 in Expanding Circle, Asian EFL classes, what kind of interpersonal roles do they perform, and what does this mean for the development of L2-mediated identity? The notion of alterity, or otherness, is used here to analyse the extent to which identity work occurs in EFL classes located in a Thai university context.…


    Directory of Open Access Journals (Sweden)

    Elke Peters


    Full Text Available This study explored the effect of two enhancement techniques on L2 learners' look-up behaviour during a reading task and word retention afterwards amongst Flemish learners of German: a Vocabulary Test Announcement and Task-induced Word Relevance. Eighty-four participants were recruited for this study. They were randomly assigned to one of two groups: 1 not forewarned of an upcoming vocabulary test (incidental condition or 2 forewarned of a vocabulary test (intentional condition. Task-induced Word Relevance was operationalized by a reading comprehension task. The relevance factor comprised two levels: plus-relevant and minus-relevant target words. Plus-relevant words needed to be looked up and used receptively in order to answer the comprehension questions. In other words, the reading comprehension task could not be accomplished without knowing the meaning of the plus-relevant words. The minus-relevant target words, on the other hand, were not linked to the reading comprehension questions. Our findings show a significant effect of Test Announcement and Word Relevance on whether a target word is looked up. In addition, Word Relevance also affects the frequency of clicks on target words. Word retention is only influenced by Task-induced Word Relevance. The effect of Word Relevance is durable.

  4. Sensitivity analysis of LOFT L2-5 test calculations

    International Nuclear Information System (INIS)

    Prosek, Andrej


    The uncertainty quantification of best-estimate code predictions is typically accompanied by a sensitivity analysis, in which the influence of the individual contributors to uncertainty is determined. The objective of this study is to demonstrate the improved fast Fourier transform based method by signal mirroring (FFTBM-SM) for the sensitivity analysis. The sensitivity study was performed for the LOFT L2-5 test, which simulates the large break loss of coolant accident. There were 14 participants in the BEMUSE (Best Estimate Methods-Uncertainty and Sensitivity Evaluation) programme, each performing a reference calculation and 15 sensitivity runs of the LOFT L2-5 test. The important input parameters varied were break area, gap conductivity, fuel conductivity, decay power etc. For the influence of input parameters on the calculated results the FFTBM-SM was used. The only difference between FFTBM-SM and original FFTBM is that in the FFTBM-SM the signals are symmetrized to eliminate the edge effect (the so called edge is the difference between the first and last data point of one period of the signal) in calculating average amplitude. It is very important to eliminate unphysical contribution to the average amplitude, which is used as a figure of merit for input parameter influence on output parameters. The idea is to use reference calculation as 'experimental signal', 'sensitivity run' as 'calculated signal', and average amplitude as figure of merit for sensitivity instead for code accuracy. The larger is the average amplitude the larger is the influence of varied input parameter. The results show that with FFTBM-SM the analyst can get good picture of the contribution of the parameter variation to the results. They show when the input parameters are influential and how big is this influence. FFTBM-SM could be also used to quantify the influence of several parameter variations on the results. However, the influential parameters could not be

  5. Low doses of flagellin-L2 multimer vaccines protect against challenge with diverse papillomavirus genotypes. (United States)

    Kalnin, Kirill; Tibbitts, Timothy; Yan, Yanhua; Stegalkina, Svetlana; Shen, Lihua; Costa, Victor; Sabharwal, Robert; Anderson, Stephen F; Day, Patricia M; Christensen, Neil; Schiller, John T; Jagu, Subhashini; Roden, Richard B S; Almond, Jeffrey; Kleanthous, Harold


    Genetically modified bacterial flagellin (Fla), a Toll-like receptor-5 (TLR5) ligand, was evaluated as a fusion partner for human papillomavirus (HPV) L2-based immunogens in two animal challenge models; either cutaneous inoculation of rabbits with HPV 'quasivirions' containing cottontail rabbit papillomavirus (CRPV) genomes that induce warts, or intra-vaginal inoculation of mice with HPV 'pseudovirions' encapsidating a luciferase reporter plasmid and measurement of bioluminescence to determine infectivity. An Escherichia coli production system was developed for flagellin-L2 (Fla-L2) fusions containing either monomeric HPV-16 L2 a.a. 11(×11-200) or oligomeric L2 comprising a fusion of the a.a. 11-88 peptides of five (Fla∼5×11-88) or eight (Fla∼8×11-88) genital HPV types. Immunogenicity and bioactivity of Fla-L2 constructs were assessed using an in vitro neutralization and cell-based TLR-5 binding assay, respectively. Efficacy was evaluated following active immunization of rabbits or mice administered 3 intramuscular doses of Fla-L2 recombinants without exogenous adjuvant, followed by challenge. In addition, passive immunization studies of naïve rabbits with serial dilutions of pooled immune sera were used to determine End-Point Protection Titers (EPPT) for each formulation against a broader spectrum of HPV quasivirions. Efficacy was assessed for up to 10 weeks on the basis of wart volume induced following challenge and results compared to licensed L1-VLP vaccines (Gardasil and Cervarix). Following active immunization at doses as low as 1 μg, Fla-L2 fusions afforded complete protection against infection (mice) and disease (rabbits) following either homologous or heterologous HPV challenge. Passive immunization with anti-L2 immune sera discriminated between the different vaccine candidates under evaluation, demonstrated the protective role of antibody and suggested the superiority of this oligomeric L2-TLR5 agonist fusion approach compared to L1-based

  6. Learning from Expository Text in L2 Reading: Memory for Causal Relations and L2 Reading Proficiency (United States)

    Hosoda, Masaya


    This study explored the relation between second-language (L2) readers' memory for causal relations and their learning outcomes from expository text. Japanese students of English as a foreign language (EFL) with high and low L2 reading proficiency read an expository text. They completed a causal question and a problem-solving test as measures of…

  7. L2 Teaching in the Wild: A Closer Look at Correction and Explanation Practices in Everyday L2 Interaction (United States)

    Theodorsdottor, Gudrun


    This article argues for a reconceptualization of the concept of "corrective feedback" for the investigation of correction practices in everyday second language (L2) interaction ("in the wild"). Expanding the dataset for L2 research as suggested by Firth and Wagner (1997) to include interactions from the wild has consequences…


    Directory of Open Access Journals (Sweden)

    Elisabetta Mauroni


    Full Text Available Il presente contributo si inserisce nel filone degli studi che hanno messo in evidenza la potenziale ricchezza della canzone come strumento di facilitazione dell’apprendimento della L2, e come mezzo per l’approccio al testo letterario per studenti di italiano L1, additandone il carattere di attività particolarmente efficace e ‘consonante’ con una prospettiva umanistico-affettiva, comunicativa, nonché socio-costruttivista. In queste pagine sono presentate alcune attività didattiche (pensate ora per gli apprendenti di italiano L2, ora per gli studenti di italiano L1 formulate a partire da alcuni testi del cantautore Claudio Baglioni (Io sono qui, Le vie dei Colori, Bolero, Fammi andar via tratti dall’album Io sono qui, 1995, edizioni CBS. I testi qui didattizzati sono utilizzabili in diverse prospettive: grammaticale, lessicale, retorica, socio-culturale, ecc.; e per diversi livelli di competenza linguistica (L2: A1-C1; L1.     Learning italian l2 through song.  A didactic contribution   This article is part of a series of studies which focus on the potential richness of songs as tools for facilitating L2 learning, as well as being a way to approach literary texts for L1 Italian students, being a particularly effective activity from a humanistic-affective, communicative and socio-constructivist point of view.  A few didactic activities are presented (designed for L2 Italian learners, or for L1 Italian learners based on songs by Claudio Baglioni (Io sono qui, Le vie dei Colori, Bolero, Fammi andar via from the album Io sono qui, 1995, edizioni CBS.  The texts were adapted for diverse didactic uses: grammatical, lexical, rhetorical, socio-cultural, etc and for different levels of linguistic competence (L2: A1-C1, L1

  9. Unconscious motivation. Part II: Implicit attitudes and L2 achievement

    Directory of Open Access Journals (Sweden)

    Ali H. Al-Hoorie


    Full Text Available This paper investigates the attitudinal/motivational predictors of second language (L2 academic achievement. Young adult learners of English as a foreign language (N = 311 completed several self-report measures and the Single-Target Implicit Association Test. Examination of the motivational profiles of high and low achievers revealed that attachment to the L1 community and the ought-to L2 self were negatively associated with achievement, while explicit attitudes toward the L2 course and implicit attitudes toward L2 speakers were positively associated with it. The relationship between implicit attitudes and achievement could not be explained either by social desirability or by other cognitive confounds, and remained significant after controlling for explicit self-report measures. Explicit–implicit congruence also revealed a similar pattern, in that congruent learners were more open to the L2 community and obtained higher achievement. The results also showed that neither the ideal L2 self nor intended effort had any association with actual L2 achievement, and that intended effort was particularly prone to social desirability biases. Implications of these findings are discussed.

  10. ASTER L2 Surface Radiance TIR V003 (United States)

    National Aeronautics and Space Administration — The ASTER L2 Surface Radiance TIR is an on-demand product generated using the five thermal infra-red (TIR) Bands (acquired either during the day or night time)...

  11. L2-gain and passivity techniques in nonlinear control

    CERN Document Server

    van der Schaft, Arjan


    This standard text gives a unified treatment of passivity and L2-gain theory for nonlinear state space systems, preceded by a compact treatment of classical passivity and small-gain theorems for nonlinear input-output maps. The synthesis between passivity and L2-gain theory is provided by the theory of dissipative systems. Specifically, the small-gain and passivity theorems and their implications for nonlinear stability and stabilization are discussed from this standpoint. The connection between L2-gain and passivity via scattering is detailed. Feedback equivalence to a passive system and resulting stabilization strategies are discussed. The passivity concepts are enriched by a generalised Hamiltonian formalism, emphasising the close relations with physical modeling and control by interconnection, and leading to novel control methodologies going beyond passivity. The potential of L2-gain techniques in nonlinear control, including a theory of all-pass factorizations of nonlinear systems, and of parametrization...

  12. Okeanos Explorer (EX1503L2): Tropical Exploration (Mapping II) (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — During EX-15-03L2, multibeam data will be collected 24 hours a day and XBT casts will be conducted at an interval defined by prevailing oceanographic conditions, but...

  13. MRI features in 17 patients with l2 hydroxyglutaric aciduria

    International Nuclear Information System (INIS)

    Fourati, Héla; Ellouze, Emna; Ahmadi, Mourad; Chaari, Dhouha; Kamoun, Fatma; Hsairi, Ines; Triki, Chahnez; Mnif, Zeineb


    l-2-Hydroxyglutaric (l-2-HG) aciduria is a rare inherited metabolic disease usually observed in children. Patients present a very slowly progressive deterioration with cerebellar ataxia, mild or severe mental retardation, and various other clinical signs including extrapyramidal and pyramidal symptoms, and seizures Goffette et al. [1]. This leukencephalopathy was first described in 1980 Duran et al. [2]. Brain magnetic resonance imaging (MRI) demonstrates nonspecific subcortical white matter (WM) loss, cerebellar atrophy and changes in dentate nuclei and putamen Steenweg et al. [3]. The diagnosis is highlighted by increased levels of l-2-HG in body fluids such as urine and cerebrospinal fluid. The purpose of this study is to retrospectively describe the brain MRI features in l-2-HG aciduria

  14. ASTER L2 Surface Radiance VNIR and SWIR V003 (United States)

    National Aeronautics and Space Administration — The ASTER L2 Surface Radiance is a multi-file product that contains atmospherically corrected data for both the Visible Near-Infrared (VNIR) and Shortwave Infrared...

  15. Feedback stabilization experiments using l = 2 equilibrium windings in Scyllac

    International Nuclear Information System (INIS)

    Bartsch, R.R.; Cantrell, E.L.; Gribble, R.F.; Freese, K.B.; Handy, L.E.; Kristal, R.; Miller, G.; Quinn, W.E.


    The confinement time in the Scyllac Sector Feedback Experiment has been extended with a pre-programmed equilibrium compensation force. This force was produced by driving a current with a flexible waveform in an additional set of l = 2 windings

  16. $L^2$ estimates for the $\\bar \\partial$ operator


    McNeal, Jeffery D.; Varolin, Dror


    This is a survey article about $L^2$ estimates for the $\\bar \\partial$ operator. After a review of the basic approach that has come to be called the "Bochner-Kodaira Technique", the focus is on twisted techniques and their applications to estimates for $\\bar \\partial$, to $L^2$ extension theorems, and to other problems in complex analysis and geometry, including invariant metric estimates and the $\\bar \\partial$-Neumann Problem.

  17. On Wilson bases in $L^2(\\mathbb{R}^d)$

    DEFF Research Database (Denmark)

    Bownik, Marcin; Sielemann Jakobsen, Mads; Lemvig, Jakob


    A Wilson system is a collection of finite linear combinations of time frequency shifts of a square integrable function. It is well known that, starting from a tight Gabor frame for $L^{2}(\\mathbb{R})$ with redundancy 2, one can construct an orthonormal Wilson basis for $L^2(\\mathbb{R})$ whose...... of redundancy $2^k$, where $k=1, 2, \\hdots, d$. These results generalize most of the known results about the existence of orthonormal Wilson bases....

  18. A model of the effect of uncertainty on the C elegans L2/L2d decision.

    Directory of Open Access Journals (Sweden)

    Leon Avery

    Full Text Available At the end of the first larval stage, the C elegans larva chooses between two developmental pathways, an L2 committed to reproductive development and an L2d, which has the option of undergoing reproductive development or entering the dauer diapause. I develop a quantitative model of this choice using mathematical tools developed for pricing financial options. The model predicts that the optimal decision must take into account not only the expected potential for reproductive growth, but also the uncertainty in that expected potential. Because the L2d has more flexibility than the L2, it is favored in unpredictable environments. I estimate that the ability to take uncertainty into account may increase reproductive value by as much as 5%, and discuss possible experimental tests for this ability.

  19. Low-energy near Earth asteroid capture using Earth flybys and aerobraking (United States)

    Tan, Minghu; McInnes, Colin; Ceriotti, Matteo


    Since the Sun-Earth libration points L1 and L2 are regarded as ideal locations for space science missions and candidate gateways for future crewed interplanetary missions, capturing near-Earth asteroids (NEAs) around the Sun-Earth L1/L2 points has generated significant interest. Therefore, this paper proposes the concept of coupling together a flyby of the Earth and then capturing small NEAs onto Sun-Earth L1/L2 periodic orbits. In this capture strategy, the Sun-Earth circular restricted three-body problem (CRTBP) is used to calculate target Lypaunov orbits and their invariant manifolds. A periapsis map is then employed to determine the required perigee of the Earth flyby. Moreover, depending on the perigee distance of the flyby, Earth flybys with and without aerobraking are investigated to design a transfer trajectory capturing a small NEA from its initial orbit to the stable manifolds associated with Sun-Earth L1/L2 periodic orbits. Finally, a global optimization is carried out, based on a detailed design procedure for NEA capture using an Earth flyby. Results show that the NEA capture strategies using an Earth flyby with and without aerobraking both have the potential to be of lower cost in terms of energy requirements than a direct NEA capture strategy without the Earth flyby. Moreover, NEA capture with an Earth flyby also has the potential for a shorter flight time compared to the NEA capture strategy without the Earth flyby.

  20. New develops in Thomson scattering diagnostics on the L-2 stellarator

    International Nuclear Information System (INIS)

    Blokh, M.A.; Larionova, N.F.


    In this paper, a multichannel plasma diagnostic system employing Thomson scattering is modernized for the L-2 stellarator. A specialized polychromator with a large field of view, high contrast, and transmission is used together with a 16-channel photoelectron recorder. The modernized system makes it possible to measure the electron temperature at three points simultaneously in the plasma column cross-section at a local electron density 3.10 12 cm-3

  1. Semantic Ambiguity Effects in L2 Word Recognition. (United States)

    Ishida, Tomomi


    The present study examined the ambiguity effects in second language (L2) word recognition. Previous studies on first language (L1) lexical processing have observed that ambiguous words are recognized faster and more accurately than unambiguous words on lexical decision tasks. In this research, L1 and L2 speakers of English were asked whether a letter string on a computer screen was an English word or not. An ambiguity advantage was found for both groups and greater ambiguity effects were found for the non-native speaker group when compared to the native speaker group. The findings imply that the larger ambiguity advantage for L2 processing is due to their slower response time in producing adequate feedback activation from the semantic level to the orthographic level.

  2. A gravity model for crustal dynamics (GEM-L2) (United States)

    Lerch, F. J.; Klosko, S. M.; Patel, G. B.; Wagner, C. A.


    The Laser Geodynamics Satellite (Lageos) was the first NASA satellite which was placed into orbit exclusively for laser ranging applications. Lageos was designed to permit extremely accurate measurements of the earth's rotation and the movement of the tectonic plates. The Goddard earth model, GEM-L2, was derived mainly on the basis of the precise laser ranging data taken on many satellites. Douglas et al. (1984) have demonstrated the utility of GEM-L2 in detecting the broadest ocean circulations. As Lageos data constitute the most extensive set of satellite laser observations ever collected, the incorporation of 2-1/2 years of these data into the Goddard earth models (GEM) has substantially advanced the geodynamical objectives. The present paper discusses the products of the GEM-L2 solution.

  3. Review of Social Interaction and L2 Classroom Discourse

    DEFF Research Database (Denmark)

    aus der Wieschen, Maria Vanessa


    Social Interaction and L2 Classroom Discourse investigates interactional practices in L2 classrooms. Using Conversation Analysis, the book unveils the processes underlying the co-construction of mutual understanding in potential interactional troubles in L2 classrooms – such as claims...... taster sessions over foreign language classrooms in monolingual contexts to English as an Additional Language settings in a multilingual context. This variety of settings allows him to examine a range of verbal and non-verbal features of classroom interaction, for example how code-switching is used......-6), and application (Chapters 7 and 8). A central focus throughout the entire book is classroom interactional competence and its influence on language learning....

  4. Studies of the magnetic configuration of an l=2 stellarator

    International Nuclear Information System (INIS)

    Fedyanin, O.I.


    The first part of this report describes a computational study of the effect of first and second order resonances on an l = 2 stellarator, taking as model the PROTO-CLEO experiment. The magnetic surfaces are computed in each case and the break up shown. The second part of the report deals with measurements made with an electron beam on the PROTO-CLEO l = 2 stellarator. The magnetic surfaces are measured by means of a movable probe which intercepts the beams. It is shown that the form of the surfaces, particularly near the separatrix, is sensitive to quite small perturbations of a resonant type. (author)

  5. L(2,1)-labelling of Circular-arc Graph


    Paul, Satyabrata; Pal, Madhumangal; Pal, Anita


    An L(2,1)-labelling of a graph $G=(V, E)$ is $\\lambda_{2,1}(G)$ a function $f$ from the vertex set V (G) to the set of non-negative integers such that adjacent vertices get numbers at least two apart, and vertices at distance two get distinct numbers. The L(2,1)-labelling number denoted by $\\lambda_{2,1}(G)$ of $G$ is the minimum range of labels over all such labelling. In this article, it is shown that, for a circular-arc graph $G$, the upper bound of $\\lambda_{2,1}(G)$ is $\\Delta+3\\omega$, ...

  6. A L2HGDH initiator methionine codon mutation in a Yorkshire terrier with L-2-hydroxyglutaric aciduria

    Directory of Open Access Journals (Sweden)

    Farias Fabiana HG


    Full Text Available Abstract Background L-2-hydroxyglutaric aciduria is a metabolic repair deficiency characterized by elevated levels of L-2-hydroxyglutaric acid in urine, blood and cerebrospinal fluid. Neurological signs associated with the disease in humans and dogs include seizures, ataxia and dementia. Case presentation Here we describe an 8 month old Yorkshire terrier that presented with episodes of hyperactivity and aggressive behavior. Between episodes, the dog’s behavior and neurologic examinations were normal. A T2 weighted MRI of the brain showed diffuse grey matter hyperintensity and a urine metabolite screen showed elevated 2-hydroxyglutaric acid. We sequenced all 10 exons and intron-exon borders of L2HGDH from the affected dog and identified a homozygous A to G transition in the initiator methionine codon. The first inframe methionine is at p.M183 which is past the mitochondrial targeting domain of the protein. Initiation of translation at p.M183 would encode an N-terminal truncated protein unlikely to be functional. Conclusions We have identified a mutation in the initiation codon of L2HGDH that is likely to result in a non-functional gene. The Yorkshire terrier could serve as an animal model to understand the pathogenesis of L-2-hydroxyglutaric aciduria and to evaluate potential therapies.

  7. Dynamics of the Sun-Earth-Moon System

    Indian Academy of Sciences (India)

    GENERAL I ARTICLE the repetition is close but not exact over the time scale of 112 synodic months. From the data studied, b:.P / P over a period of 112 luna- tion is 0.3/27.3 = 0.011. Therefore b:.a/a = 2/3{tl.P/ P). = 0.007. Thus on the larger time scale of about 9 years tl.E / E varies by about 0.7 percent. This may be com-.

  8. Sounds of space: listening to the Sun-Earth connection (United States)

    Craig, N.; Mendez, B.; Luhmann, J.; Sircar, I.


    NASA's STEREO/IMPACT Mission includes an Education and Public Outreach component that seeks to offer national programs for broad audiences highlighting the mission's solar and geo-space research. In an effort to make observations of the Sun more accessible and exciting for a general audience, we look for alternative ways to represent the data. Scientists most often represent data visually in images, graphs, and movies. However, any data can also be represented as sound audible to the human ear, a process known as sonification. We will present our plans for an exciting prototype program that converts the science results of solar energetic particle data to sound. We plan to make sounds, imagery, and data available to the public through the World Wide Web where they may create their own sonifications, as well as integrate this effort to a science museum kiosk format. The kiosk station would include information on the STEREO mission and monitors showing images of the Sun from each of STEREO's two satellites. Our goal is to incorporate 3D goggles and a headset into the kiosk, allowing visitors to see the current or archived images in 3D and hear stereo sounds resulting from sonification of the corresponding data. Ultimately, we hope to collaborate with composers and create musical works inspired by these sounds and related solar images.

  9. Transient shock waves in heliosphere and Sun-Earth relations

    International Nuclear Information System (INIS)

    Voeroes, Z.


    The problem of shock waves, caused by solar activity in the Earth's magnetosphere and its magnetic field, is discussed. All types of shock waves have their origin either in solar corona effects or in solar eruptions. Ionospheric and magnetospheric effects, such as X and gamma radiation, particle production, geomagnetic storms and shock waves, caused by solar activity, are dealt with and attempts are made to explain their interdependence. The origin and propagation of coronal shock waves, interplanetary shock waves and geomagnetic field disorders are described and their relations discussed. The understanding of the solar corona and wind phenomena seems to allow prediction of geomagnetic storms. The measurement and analysis of solar activity and its effects could yield useful information about shock waves physics, geomagnetosphere structure and relations between the Earth and the Sun. (J.J.). 7 figs., 1 tab., 37 refs

  10. The Maunder minimum and the variable sun-earth connection

    CERN Document Server

    Wei Hock Soon, Willie


    This book takes an excursion through solar science, science history, and geoclimate with a husband and wife team who revealed some of our sun's most stubborn secrets. E Walter and Annie S D Maunder's work helped in understanding our sun's chemical, electromagnetic and plasma properties. They knew the sun's sunspot migration patterns and its variable, climate-affecting, inactive and active states in short and long time frames. An inactive solar period starting in the mid-seventeenth century lasted approximately seventy years, one that E Walter Maunder worked hard to make us understand: the Maun

  11. L2 Processing of Plural Inflection in English (United States)

    Song, Yoonsang


    This study investigates (1) whether late second language (L2) learners can attain native-like knowledge of English plural inflection even when their first language (L1) lacks an equivalent and (2) whether they construct hierarchically structured representations during online sentence processing like native speakers. In a self-paced reading task,…

  12. Evidence from adult L1 Afrikaans L2 French

    African Journals Online (AJOL)

    results of this study show that a large number of the L2 learners had indeed acquired ... position in V2-languages (such as German) and in third position in non-V2 ... L1, allows construction types x and y but he will have no problem acquiring .... Modern Foreign Languages at Stellenbosch University at the time of testing.

  13. Negative Transfer Effects on L2 Word Order Processing. (United States)

    Erdocia, Kepa; Laka, Itziar


    Does first language (L1) word order affect the processing of non-canonical but grammatical syntactic structures in second language (L2) comprehension? In the present study, we test whether L1-Spanish speakers of L2-Basque process subject-verb-object (SVO) and object-verb-subject (OVS) non-canonical word order sentences of Basque in the same way as Basque native speakers. Crucially, while OVS orders are non-canonical in both Spanish and Basque, SVO is non-canonical in Basque but is the canonical word order in Spanish. Our electrophysiological results showed that the characteristics of L1 affect the processing of the L2 even at highly proficient and early-acquired bilingual populations. Specifically, in the non-native group, we observed a left anterior negativity-like component when comparing S and O at sentence initial position and a P600 when comparing those elements at sentence final position. Those results are similar of those reported by Casado et al. (2005) for native speakers of Spanish indicating that L2-Basque speakers rely in their L1-Spanish when processing SVO-OVS word order sentences. Our results favored the competition model (MacWhinney, 1997).

  14. Negative Transfer Effects on L2 Word Order Processing

    Directory of Open Access Journals (Sweden)

    Kepa Erdocia


    Full Text Available Does first language (L1 word order affect the processing of non-canonical but grammatical syntactic structures in second language (L2 comprehension? In the present study, we test whether L1-Spanish speakers of L2-Basque process subject–verb–object (SVO and object–verb–subject (OVS non-canonical word order sentences of Basque in the same way as Basque native speakers. Crucially, while OVS orders are non-canonical in both Spanish and Basque, SVO is non-canonical in Basque but is the canonical word order in Spanish. Our electrophysiological results showed that the characteristics of L1 affect the processing of the L2 even at highly proficient and early-acquired bilingual populations. Specifically, in the non-native group, we observed a left anterior negativity-like component when comparing S and O at sentence initial position and a P600 when comparing those elements at sentence final position. Those results are similar of those reported by Casado et al. (2005 for native speakers of Spanish indicating that L2-Basque speakers rely in their L1-Spanish when processing SVO–OVS word order sentences. Our results favored the competition model (MacWhinney, 1997.

  15. Posters, Self-Directed Learning, and L2 Vocabulary Acquisition (United States)

    Cetin, Yakup; Flamand, Lee


    Posters, either as promotions by various ELT publishing houses or prepared by ELT teachers and students, are widely used on the walls of many foreign language classrooms. Many of them consist of colourful pictures along with L2 vocabulary, grammar, and texts in order to contribute to the foreign language learning process. However, many ELT…

  16. Unconscious Motivation. Part II: Implicit Attitudes and L2 Achievement (United States)

    Al-Hoorie, Ali H.


    This paper investigates the attitudinal/motivational predictors of second language (L2) academic achievement. Young adult learners of English as a foreign language (N = 311) completed several self-report measures and the Single-Target Implicit Association Test. Examination of the motivational profiles of high and low achievers revealed that…

  17. Generators with interior degeneracy on spaces of L^2 type

    Directory of Open Access Journals (Sweden)

    Genni Fragnelli


    Full Text Available We consider operators in divergence and in nondivergence form with degeneracy at the interior of the space domain. Characterizing the domain of the operators, we prove that they generate positive analytic semigroups on spaces of L^2 type. Finally, some applications to linear and semilinear parabolic evolution problems and to linear hyperbolic ones are presented.

  18. Discourse Connectives in L1 and L2 Argumentative Writing (United States)

    Hu, Chunyu; Li, Yuanyuan


    Discourse connectives (DCs) are multi-functional devices used to connect discourse segments and fulfill interpersonal levels of discourse. This study investigates the use of selected 80 DCs within 11 categories in the argumentative essays produced by L1 and L2 university students. The analysis is based on the International Corpus Network of Asian…

  19. Selective Listening in L2 Learners of French (United States)

    Graham, Suzanne; Santos, Denise


    This paper considers the issue raised in 2008 by Gillian Brown in her article "Selective listening" regarding whether nouns are "privileged" in memory over verbs during listening tasks, and whether attention to nouns, at least in the early stages of L2 learning, is a desirable strategy to be taught to learners, as Brown…

  20. Memorization versus Semantic Mapping in L2 Vocabulary Acquisition (United States)

    Khoii, Roya; Sharififar, Samira


    This study investigated the effects of two cognitive strategies, rote memorization and semantic mapping, on L2 vocabulary acquisition. Thirty-eight intermediate female EFL learners divided into two experimental groups participated in this study. Each experimental group used one of the strategies for vocabulary acquisition. After the four-month…

  1. Facebook Activities and the Investment of L2 Learners (United States)

    Shafie, Latisha Asmaak; Yaacob, Aizan; Singh, Paramjit Kaur Karpal


    The article discusses the investment of L2 learners in the English language on Facebook that they portrayed through their Facebook activities. It studied four informants consisted of diploma students in a Malaysian university. The study consisted of 14 weeks of online observation and semi-structured interviews. Data were collected from online…

  2. Enhancing L2 Reading Comprehension with Hypermedia Texts: Student Perceptions (United States)

    Garrett-Rucks, Paula; Howles, Les; Lake, William M.


    This study extends current research about L2 hypermedia texts by investigating the combined use of audiovisual features including: (a) Contextualized images, (b) rollover translations, (c) cultural information, (d) audio explanations and (e) comprehension check exercises. Specifically, student perceptions of hypermedia readings compared to…

  3. A new characterization of L2(p) by NSE

    Indian Academy of Sciences (India)

    In this paper we give a new characterization of simple group L2(p) with ... Introduction. Throughout this paper, all groups are finite and G denotes a group. .... [5] Mazurov V D and Khukhro E I, Unsolved Problems in Group Theory, the Kourovka.

  4. Task type and incidental L2 vocabulary learning: Repetition versus ...

    African Journals Online (AJOL)

    This study investigated the effect of task type on incidental L2 vocabulary learning. The different tasks investigated in this study differed in terms of repetition of encounters and task involvement load. In a within-subjects design, 72 Iranian learners of English practised 18 target words in three exercise conditions: three ...

  5. Wavelet Decomposition Method for $L_2/$/TV-Image Deblurring

    KAUST Repository

    Fornasier, M.; Kim, Y.; Langer, A.; Schö nlieb, C.-B.


    In this paper, we show additional properties of the limit of a sequence produced by the subspace correction algorithm proposed by Fornasier and Schönlieb [SIAM J. Numer. Anal., 47 (2009), pp. 3397-3428 for L 2/TV-minimization problems. An important

  6. The Effect of Conversation Engagement on L2 Learning Opportunities (United States)

    Chen, Wenxue


    This article reviews patterns of interaction (i.e. learner role relationships) in peer communicative tasks, and uses data collected from different tasks to explain what happens in peer interaction and its impact on the learning opportunities interlocutors create for each other. It proposes that, with L2 peer interaction gaining popularity in…

  7. Influence of musical training on perception of L2 speech

    NARCIS (Netherlands)

    Sadakata, M.; Zanden, L.D.T. van der; Sekiyama, K.


    The current study reports specific cases in which a positive transfer of perceptual ability from the music domain to the language domain occurs. We tested whether musical training enhances discrimination and identification performance of L2 speech sounds (timing features, nasal consonants and

  8. L2 Reading Motivation among Sri Lankan University Students (United States)

    Dhanapala, Kusumi Vasantha; Hirakawa, Yukiko


    This study investigated the extent of the motivational processes that facilitated the text comprehension among 406 Sri Lankan university students in Sri Lanka. Students' L2 text comprehension and reading motivation were assessed using a reading comprehension test and a reading motivation and attitude questionnaire. The Principal Componential…

  9. Automated Scoring of L2 Spoken English with Random Forests (United States)

    Kobayashi, Yuichiro; Abe, Mariko


    The purpose of the present study is to assess second language (L2) spoken English using automated scoring techniques. Automated scoring aims to classify a large set of learners' oral performance data into a small number of discrete oral proficiency levels. In automated scoring, objectively measurable features such as the frequencies of lexical and…

  10. Developing Intentionality and L2 Classroom Task-Engagement (United States)

    Stelma, Juup


    This paper extends work on "intentionality", from philosophy, psychology and education to an exploration of learners' meaning-making in L2 classroom task-engagement. The paper draws on both phenomenological and folk-psychological perspectives on intentionality, and employs John R. Searle's intrinsic (mental) and derived (observable)…

  11. New Perspectives on Multilingualism and L2 Acquisition: An Introduction (United States)

    de Zarobe, Leyre Ruiz; de Zarobe, Yolanda Ruiz


    This article focuses on the description of one of the main features of current multilingualism, complexity, through a selection of issues related to its role in L2 acquisition, as the proper notion of multilingualism, multilingualism as a social phenomenon and multilingualism as a multidimensional phenomenon. We also present several aspects of…

  12. Teaching L2 Pragmatics: Opportunities for Continuing Professional Development (United States)

    Vellenga, Heidi


    Teaching L2 pragmatics is often not covered in teacher education programs, and is an excellent area for continuing professional development. As part of a larger project on instructed interlanguage pragmatics, volunteer instructor participants were asked to teach a series of lessons on pragmatics to university-aged (19-23) ESL learners in ESL and…

  13. Deconstructing Gender Stereotyping through Literature in L2 (United States)

    Yulita, Leticia


    While it is generally accepted that literature fosters (inter)cultural learning, few qualitative studies have sought to understand in what ways interculturality is developed. This article investigates the development of Spanish L2 students' intercultural awareness through the reading of a short story entitled "Norma y Ester" by Argentine…

  14. A dynamic usage based perspective on L2 writing

    NARCIS (Netherlands)

    Verspoor, M.H.; Schmid, M.S.; Xu, X.

    The goal of this study was to explore the contribution that a dynamic usage based (DUB) perspective can bring to the establishment of objective measures to assess L2 learners' written texts and at the same time to gain insight into the dynamic process of language development. Four hundred and thirty

  15. Face and enactment of identities in the L2 classroom

    CERN Document Server

    Kidd, Joshua Alexander


    This book examines student identities as revealed through the pragmatics of face during an English L2 classroom interaction between Japanese students and a native speaker teacher. This study reminds us that what may be considered acceptable language use in the classroom can shift dramatically according to social, cultural and individual contexts.

  16. Analisis Jaringan VPN Menggunakan PPTP dan L2TP

    Directory of Open Access Journals (Sweden)

    Syariful Ikhwan


    Full Text Available VPN adalah teknologi yang membuat jaringan private (pribadi dengan menggunakan jaringan publik agar proses pertukaran data menjadi aman. Teknologi VPN biasanya diterapkan untuk koneksi antara kantor pusat dan kantor cabang. Dinhubkominfo Kabupaten Banyumas sebagai tempat penelitian memiliki beberapa kantor cabang (SKPD. Data yang dipertukarkan antar kantor cabang pada Dinhubkominfo terdiri dari beberapa jenis, namun pada penelitian ini hanya difokuskan pada pertukaran layanan FTP. Teknologi vpn yang saat ini digunakan pada jaringan Dinhubkominfo adalah PPTP. Akan tetapi, penggunaan teknologi tersebut belum tersebut masih belum diketahui tingkat performansi jaringan dibandingkan dengan penggunaan teknologi vpn yang lain. Pada penelitian ini akan dibandingkan penggunaan dua teknologi vpn yang berbeda yaitu antara PPTP dan L2TP, dimana parameter yang digunakan adalah throughput, delay, jitter, dan packet loss. Proses pengambilan data dilakukan dengan menambahkan beban trafik sebesar 512 kbps, 1024 kbps, dan 2048 kbps. Dari hasil penelitian diperoleh data bahwa, rata-rata nilai Delay pada L2TP lebih besar hingga 41% dibanding saat menggunakan PPTP, rata-rata Throughput PPTP naik hingga 34% dibandingkan L2TP, Rata-rata Jitter pada PPTP lebih besar hingga 44% dibandingkan L2TP, sedangkan packet loss yang terjadi pada masing-masing layanan vpn adalah 0

  17. Optimization of multimeric human papillomavirus L2 vaccines.

    Directory of Open Access Journals (Sweden)

    Subhashini Jagu

    Full Text Available We sought to define the protective epitopes within the amino terminus of human papillomavirus (HPV type 16 minor capsid protein L2. Passive transfer of mice with rabbit antisera to HPV16 L2 peptides 17-36, 32-51 and 65-81 provided significant protection against vaginal HPV16 challenge, whereas antisera to 47-66, 108-120 or 373-392 did not. Vaccination with L1 virus-like particles induces a high titer, but generally type-restricted neutralizing antibody response. Conversely, vaccination with L2 11-88, especially multimers thereof, induces antibodies that neutralize a broad range of papillomavirus types, albeit at lower titers than for L1 VLP. With the intent of enhancing the immunogenicity and the breadth of protection by focusing the immune response to the key protective epitopes, we designed L2 fusion proteins consisting of residues ∼11-88 of eight divergent mucosal HPV types 6, 16, 18, 31, 39, 51, 56, 73 (11-88×8 or residues ∼13-47 of fifteen HPV types (13-47×15. The 11-88×8 was significantly more immunogenic than 13-47×15 in Balb/c mice regardless of the adjuvant used, suggesting the value of including the 65-81 protective epitope in the vaccine. Since the L2 47-66 peptide antiserum failed to elicit significant protection, we generated an 11-88×8 construct deleted for this region in each subunit (11-88×8Δ. Mice were vaccinated with 11-88×8 and 11-88×8Δ to determine if deletion of this non-protective epitope enhanced the neutralizing antibody response. However, 11-88×8Δ was significantly less immunogenic than 11-88×8, and even the addition of a known T helper epitope, PADRE, to the construct (11-88×8ΔPADRE failed to recover the immunogenicity of 11-88×8 in C57BL/6 mice, suggesting that while L2 47-66 is not a critical protective or T helper epitope, it nevertheless contributes to the immunogenicity of the L2 11-88×8 multimer vaccine.

  18. On stochastic modeling of the modernized global positioning system (GPS) L2C signal

    International Nuclear Information System (INIS)

    Elsobeiey, Mohamed; El-Rabbany, Ahmed


    In order to take full advantage of the modernized GPS L2C signal, it is essential that its stochastic characteristics and code bias be rigorously determined. In this paper, long sessions of GPS measurements are used to study the stochastic characteristics of the modernized GPS L2C signal. As a byproduct, the stochastic characteristics of the legacy GPS signals, namely C/A and P2 codes, are also determined, which are used to verify the developed stochastic model of the modernized signal. The differential code biases between P2 and C2, DCB P2-C2 , are also estimated using the Bernese GPS software. It is shown that the developed models improved the precise point positioning (PPP) solution and convergence time

  19. No evidence for dualism in function and receptors: PD-L2/B7-DC is an inhibitory regulator of human T cell activation. (United States)

    Pfistershammer, Katharina; Klauser, Christoph; Pickl, Winfried F; Stöckl, Johannes; Leitner, Judith; Zlabinger, Gerhard; Majdic, Otto; Steinberger, Peter


    The B7 family member programmed-death-1-ligand 2 (PD-L2/B7-DC) is a ligand for programmed-death-receptor 1 (PD-1), a receptor involved in negative regulation of T cell activation. Several independent studies have reported that PD-L2, however, can also potently costimulate murine T cells via an additional yet unidentified receptor. In this study, we evaluated the contribution of PD-L2 to the activation of human T cells using a novel system of engineered T cell stimulators that expresses membrane-bound anti-CD3 antibodies. Analyzing early activation markers, cytokine production and proliferation, we found PD-L2 to consistently inhibit T cell activation. PD-L2 inhibition affected CD4+ and CD8+ T cells and was not abrogated by costimulation via CD28. Blocking PD-1 reverted the inhibitory effect of PD-L2, demonstrating involvement of this pathway. In human T cells, we found no evidence for any of the costimulatory effects described for PD-L2 in murine systems. In line with our functional data that do not point to stimulatory PD-L2-ligands, we show that binding of PD-L2-immunoglobulin to activated human T cells is abrogated by PD-1 antibodies. Our results demonstrate that PD-L2 negatively regulates human T cell activation and thus might be a candidate molecule for immunotherapeutic approaches aimed to attenuate pathological immune responses.

  20. L1-L2 Transfer in the Narrative Styles of Chinese EFL Learners' Written Personal Narratives (United States)

    Su, I-Ru; Chou, Yi-Chun


    Most of the research on second language (L2) narratives has focused on whether or how L2 learners carry their L1 narrative styles into L2 narration; few studies have explored whether L2 learners' knowledge of the L2 also in turn affects their L1 narrative performance. The present study attempted to probe the issue of cultural transfer in narrative…

  1. Literary Language in Development of L2 Competence

    Directory of Open Access Journals (Sweden)

    Dan Lu


    Full Text Available Nowadays it is believed that language in daily communication rather than literary language should be the target of learning in L2 education. This is mainly because literary language is said to be uncommon in life. This paper reports on a study in which some Hong Kong ESL learners’ English proficiency was re-examined through literary texts. These learners had reached intermediate or advanced levels of English prior to the study and were generally competent in daily English. However, many of them encountered difficulty in understanding literary language. Their proficiency in general English test could not match their performances in understanding literary works. The findings reveal that learners who are strong in general proficiency may not be good in understanding literary language. Lack of literary language in the curriculum results in a false and distorted picture about the learners’ proficiency. Literary language helps upgrade L2 learners’ real proficiency in the target language.

  2. Influence of syllable structure on L2 auditory word learning. (United States)

    Hamada, Megumi; Goya, Hideki


    This study investigated the role of syllable structure in L2 auditory word learning. Based on research on cross-linguistic variation of speech perception and lexical memory, it was hypothesized that Japanese L1 learners of English would learn English words with an open-syllable structure without consonant clusters better than words with a closed-syllable structure and consonant clusters. Two groups of college students (Japanese group, N = 22; and native speakers of English, N = 21) learned paired English pseudowords and pictures. The pseudoword types differed in terms of the syllable structure and consonant clusters (congruent vs. incongruent) and the position of consonant clusters (coda vs. onset). Recall accuracy was higher for the pseudowords in the congruent type and the pseudowords with the coda-consonant clusters. The syllable structure effect was obtained from both participant groups, disconfirming the hypothesized cross-linguistic influence on L2 auditory word learning.

  3. Object Tracking via 2DPCA and l2-Regularization

    Directory of Open Access Journals (Sweden)

    Haijun Wang


    Full Text Available We present a fast and robust object tracking algorithm by using 2DPCA and l2-regularization in a Bayesian inference framework. Firstly, we model the challenging appearance of the tracked object using 2DPCA bases, which exploit the strength of subspace representation. Secondly, we adopt the l2-regularization to solve the proposed presentation model and remove the trivial templates from the sparse tracking method which can provide a more fast tracking performance. Finally, we present a novel likelihood function that considers the reconstruction error, which is concluded from the orthogonal left-projection matrix and the orthogonal right-projection matrix. Experimental results on several challenging image sequences demonstrate that the proposed method can achieve more favorable performance against state-of-the-art tracking algorithms.

  4. Multiwavelet packets and frame packets of L2( d)

    Indian Academy of Sciences (India)

    Springer Verlag Heidelberg #4 2048 1996 Dec 15 10:16:45

    For a nice exposition of wavelet packets of L2( ) with dilation 2, see [11]. ..... p∈ d hr lm(ξ)cjp. {. ∑ q∈ d. ˆϕm(ξ + 2qπ) ˆϕj (ξ + 2qπ). } ·e−i〈k,Bξ〉 e i〈p, ξ〉 dξ ...... [14] Rudin W, Fourier Analysis on Groups (New York: John Wiley and Sons) (1962).

  5. Initiating round robins in the L2 classroom - preliminary observations

    DEFF Research Database (Denmark)

    Mortensen, Kristian; Hazel, Spencer


    Complementing recent interactional research on the contingent operation of online task accomplishment, this paper deals with a specific way of organizing and managing tasks in plenary L2 classrooms – namely the round robin. This may seem like a “traditional” and rigid form of classroom organizati...... and artefacts and graphic structures that are used not only as mediating tools in the (supposed) learning relevant activity, but also as structurally relevant features to organize the ongoing interaction, in which these activities emerge....

  6. Multiple Grammars and the Logic of Learnability in L2

    Directory of Open Access Journals (Sweden)

    Tom W Roeper


    Full Text Available The goal of this article is to enhance the technical description of multi-lingual speakers in terms of a theoryof Multiple Grammars where more than one language utilizes a grammar. The challenge of V2 and itsimplications for interfaces from the perspective of the L2 learner is the focus. A number of constructionsare considered including: Quotation, Topicaliation, Empty subjects and Objects, Expletives, and Subject-auxiliary inversoni.

  7. Acquisition of L2 Japanese Geminates: Training with Waveform Displays (United States)

    Motohashi-Saigo, Miki; Hardison, Debra M.


    The value of waveform displays as visual feedback was explored in a training study involving perception and production of L2 Japanese by beginning-level L1 English learners. A pretest-posttest design compared auditory-visual (AV) and auditory-only (A-only) Web-based training. Stimuli were singleton and geminate /t,k,s/ followed by /a,u/ in two…


    Directory of Open Access Journals (Sweden)

    Filippo Zanoli


    Full Text Available Mai come oggi le classi (di Italiano L2, ma non solo sono così fortemente colonizzate dal digitale. L’invasione si è palesata sotto forma di telefonini cellulari (smartphone e tablet dotati di connessione internet e infinite potenzialità sotto forma di applicazioni che possono sia aiutare il discente sia, se male impiegati, ostacolarlo dall’intraprendere un proficuo percorso di apprendimento. Compito dell’insegnante di lingua è circoscrivere l’influenza e l’uso di tali strumenti – che non sono mero techné, ma un modo di funzionare di una generazione – non  per vietarli ma per proporre un approccio e un loro utilizzo costruttivo quali mezzi dalle grandi potenzialità nell’apprendimento di una lingua straniera.     The 1st class – Smartphones and Italian L2/FL   Classrooms (for Italian L2, but not only have never before been so strongly digitally oriented. This invasion is made tangible by smartphones and tablets equipped with internet connections and infinite potential thanks to applications which can help students in their studies, or hinder them if used incorrectly. The language teacher’s task is to circumscribe the influence and use of these tools– which are not mere techné, but the way an entire generation functions – not to prohibit using them but to propose using them constructively, thanks to their great potential for foreign language learning.

  9. Positive and negative emotions underlie motivation for L2 learning

    Directory of Open Access Journals (Sweden)

    Peter D. MacIntyre


    Full Text Available The role of basic emotions in SLA has been underestimated in both research and pedagogy. The present article examines 10 positive emotions (joy, gratitude, serenity, interest, hope, pride, amusement, inspiration, awe, and love and 9 negative emotions (anger, contempt, disgust, embarrassment, guilt, hate, sadness, feeling scared, and being stressed. The emotions are correlated with core variables chosen from three well-known models of L2 motivation: Gardner’s integrative motive, Clément’s social-contextual model, and Dörnyei’s L2 self system. Respondents came from Italian secondary schools, and most participants were from monolingual Italian speaking homes. They described their motivation and emotion with respect to learning German in a region of Italy (South Tyrol that features high levels of contact between Italians and Germans. Results show that positive emotions are consistently and strongly correlated with motivation-related variables. Correlations involving negative emotions are weaker and less consistently implicated in motivation. The positivity ratio, that is, the relative prevalence of positive over negative emotion, showed strong correlations with all of the motivation constructs. Regression analysis supports the conclusion that a variety of emotions, not just one or two key ones, are implicated in L2 motivation processes in this high-contact context.

  10. Accounting for L2 learners’ errors in word stress placement

    Directory of Open Access Journals (Sweden)

    Clara Herlina Karjo


    Full Text Available Stress placement in English words is governed by highly complicated rules. Thus, assigning stress correctly in English words has been a challenging task for L2 learners, especially Indonesian learners since their L1 does not recognize such stress system. This study explores the production of English word stress by 30 university students. The method used for this study is immediate repetition task. Participants are instructed to identify the stress placement of 80 English words which are auditorily presented as stimuli and immediately repeat the words with correct stress placement. The objectives of this study are to find out whether English word stress placement is problematic for L2 learners and to investigate the phonological factors which account for these problems. Research reveals that L2 learners have different ability in producing the stress, but three-syllable words are more problematic than two-syllable words. Moreover, misplacement of stress is caused by, among others, the influence of vowel lenght and vowel height.

  11. The research of the coupled orbital-attitude controlled motion of celestial body in the neighborhood of the collinear libration point L1 (United States)

    Shmyrov, A.; Shmyrov, V.; Shymanchuk, D.


    This article considers the motion of a celestial body within the restricted three-body problem of the Sun-Earth system. The equations of controlled coupled attitude-orbit motion in the neighborhood of collinear libration point L1 are investigated. The translational orbital motion of a celestial body is described using Hill's equations of circular restricted three-body problem of the Sun-Earth system. Rotational orbital motion is described using Euler's dynamic equations and quaternion kinematic equation. We investigate the problem of stability of celestial body rotational orbital motion in relative equilibrium positions and stabilization of celestial body rotational orbital motion with proposed control laws in the neighborhood of collinear libration point L1. To study stabilization problem, Lyapunov function is constructed in the form of the sum of the kinetic energy and special "kinematic function" of the Rodriguez-Hamiltonian parameters. Numerical modeling of the controlled rotational motion of a celestial body at libration point L1 is carried out. The numerical characteristics of the control parameters and rotational motion are given.

  12. The impact of language co-activation on L1 and L2 speech fluency. (United States)

    Bergmann, Christopher; Sprenger, Simone A; Schmid, Monika S


    Fluent speech depends on the availability of well-established linguistic knowledge and routines for speech planning and articulation. A lack of speech fluency in late second-language (L2) learners may point to a deficiency of these representations, due to incomplete acquisition. Experiments on bilingual language processing have shown, however, that there are strong reasons to believe that multilingual speakers experience co-activation of the languages they speak. We have studied to what degree language co-activation affects fluency in the speech of bilinguals, comparing a monolingual German control group with two bilingual groups: 1) first-language (L1) attriters, who have fully acquired German before emigrating to an L2 English environment, and 2) immersed L2 learners of German (L1: English). We have analysed the temporal fluency and the incidence of disfluency markers (pauses, repetitions and self-corrections) in spontaneous film retellings. Our findings show that learners to speak more slowly than controls and attriters. Also, on each count, the speech of at least one of the bilingual groups contains more disfluency markers than the retellings of the control group. Generally speaking, both bilingual groups-learners and attriters-are equally (dis)fluent and significantly more disfluent than the monolingual speakers. Given that the L1 attriters are unaffected by incomplete acquisition, we interpret these findings as evidence for language competition during speech production. Copyright © 2015. Published by Elsevier B.V.

  13. English L2 reading getting to the bottom

    CERN Document Server

    Birch, Barbara M


    English L2 Reading, Third Edition offers teachers research-based insights into bottom-up skills in reading English as a second language and a solid foundation on which to build reading instruction. Core linguistic and psycholinguistic concepts are presented within the context of their application to teaching. The goal is to balance or supplement (not replace) top-down approaches and methodologies with effective low-level options for teaching English reading. The text's pedagogical features- Questions, Study Guide Questions. Discussion Questions, Spotlight on Teaching sections- engage readers o

  14. Strong limit theorems in noncommutative L2-spaces

    CERN Document Server

    Jajte, Ryszard


    The noncommutative versions of fundamental classical results on the almost sure convergence in L2-spaces are discussed: individual ergodic theorems, strong laws of large numbers, theorems on convergence of orthogonal series, of martingales of powers of contractions etc. The proofs introduce new techniques in von Neumann algebras. The reader is assumed to master the fundamentals of functional analysis and probability. The book is written mainly for mathematicians and physicists familiar with probability theory and interested in applications of operator algebras to quantum statistical mechanics.

  15. l-2-Nitrimino-1,3-diazepane-4-carboxylic acid

    Directory of Open Access Journals (Sweden)

    Harutyun A. Karapetyan


    Full Text Available The cyclic form of l-nitroarginine, C6H10N4O4, crystallizes with two independent molecules in the asymmetric unit. According to the geometrical parameters, similar in both molecules, the structure corresponds to that of l-2-nitrimino-1,3-diazepane-4-carboxylic acid; there are, however, conformational differences between the independent molecules, one of them being close to a twisted chair while the other might be described as a rather flattened boat. All six active H atoms in the two molecules are involved in hydrogen bonds, two of which are intramolecular and four intermolecular, forming an infinite chain of molecules along the b axis.

  16. Triana Safehold: A New Gyroless, Sun-Pointing Attitude Controller (United States)

    Chen, J.; Morgenstern, Wendy; Garrick, Joseph


    Triana is a single-string spacecraft to be placed in a halo orbit about the sun-earth Ll Lagrangian point. The Attitude Control Subsystem (ACS) hardware includes four reaction wheels, ten thrusters, six coarse sun sensors, a star tracker, and a three-axis Inertial Measuring Unit (IMU). The ACS Safehold design features a gyroless sun-pointing control scheme using only sun sensors and wheels. With this minimum hardware approach, Safehold increases mission reliability in the event of a gyroscope anomaly. In place of the gyroscope rate measurements, Triana Safehold uses wheel tachometers to help provide a scaled estimation of the spacecraft body rate about the sun vector. Since Triana nominally performs momentum management every three months, its accumulated system momentum can reach a significant fraction of the wheel capacity. It is therefore a requirement for Safehold to maintain a sun-pointing attitude even when the spacecraft system momentum is reasonably large. The tachometer sun-line rate estimation enables the controller to bring the spacecraft close to its desired sun-pointing attitude even with reasonably high system momentum and wheel drags. This paper presents the design rationale behind this gyroless controller, stability analysis, and some time-domain simulation results showing performances with various initial conditions. Finally, suggestions for future improvements are briefly discussed.

  17. Smart Grid Enabled L2 EVSE for the Commercial Market

    Energy Technology Data Exchange (ETDEWEB)

    Weeks, John [Eaton Corporation, Arden, NC (United States); Pugh, Jerry [Eaton Corporation, Arden, NC (United States)


    In 2011, the DOE issued Funding Opportunity DE-FOA-0000554 as a means of addressing two major task areas identified by the Grid Integration Tech Team (GITT) that would help transition Electric vehicles from a market driven by early adopters and environmental supporters to a market with mainstream volumes. Per DE-FOA-0000554, these tasks were: To reduce the cost of Electric Vehicle Supply Equipment (EVSE), thereby increasing the likelihood of the build out of EV charging infrastructure. The goal of increasing the number of EVSE available was to ease concerns over range anxiety, and promote the adoption of electric vehicles: To allow EV loads to be managed via the smart grid, thereby maintaining power quality, reliability and affordability, while protecting installed distribution equipment. In December of that year, the DOE awarded one of the two contracts targeted toward commercial EVSE to Eaton, and in early 2012, we began in earnest the process of developing a Smart Grid Enable L2 EVSE for the Commercial Market (hereafter known as the DOE Charger). The design of the Smart Grid Enabled L2 EVSE was based primarily on the FOA requirements along with input from the Electric Transportation Infrastructure product line (hereafter ETI) marketing team who aided in development of the customer requirements.

  18. A refined gravity model from Lageos /GEM-L2/ (United States)

    Lerch, F. J.; Klosko, S. M.; Patel, G. B.


    Lageos satellite laser ranging (SLR) data taken over a 2.5 yr period were employed to develop the Goddard Earth Model GEM-L2, a refined gravity field model. Additional data was gathered with 30 other satellites, resulting in spherical harmonics through degree and order 20, based on over 600,000 measurements. The Lageos data was accurate down to 10 cm, after which the GEM 9 data were used to make adjustments past order 7. The resolution of long wavelength activity, through degree and order 4, was made possible by the Lageos data. The GEM-L2 model features a 20 x 20 geopotential, tracking station coordinates (20), 5-day polar motion and A1-UT1 values, and a GM value of 398,600.607 cu km/sq sec. The accuracy of station positioning has been raised to within 6 cm total position globally and within 1.8 cm in baselines. It is concluded that SLR is useful for measuring tectonic plate motions and inter-plate deformations.


    Directory of Open Access Journals (Sweden)

    J. Scott Payne


    Full Text Available Recently a number of quasi-experimental studies have investigated the potential of a cross-modality transfer of second language competency between real-time, conversational exchange via text and speech (Abrams, 2003; Beauvious, 1998; Kost, 2004; Payne & Whitney, 2002. Payne and Whitney employed Levelt's (1989 model of language production and concepts from working memory as a rationale for a hypothesized connection between synchronous computer-mediated communication (SCMC and second language (L2 speech and as a basis for predicting the differential contributions of SCMC to the L2 oral proficiency development.This study extends the psycholinguistic framework reported in Payne and Whitney (2002 with discourse and corpus analytic techniques to explore how individual differences in working memory capacity may affect the frequency of repetition and other patterns of language use in chatroom discourse. Working memory capacity was measured by a reading span and nonword repetition test. Oral proficiency was measured with a speaking task that solicited a 5-minute speech sample and was scored based on a holistic scale. The data collected from 20 chat sessions were analyzed for occurrences of repetition and relexicalization, as well as language output measures. Findings suggest a connection between working memory and language output as measured in this study.

  20. Acquisition of L2 Japanese Geminates: Training with Waveform Displays

    Directory of Open Access Journals (Sweden)

    Miki Motohashi-Saigo


    Full Text Available The value of waveform displays as visual feedback was explored in a training study involving perception and production of L2 Japanese by beginning-level L1 English learners. A pretest-posttest design compared auditory-visual (AV and auditory-only (A-only Web-based training. Stimuli were singleton and geminate /t,k,s/ followed by /a,u/ in two conditions (isolated words, carrier sentences. Fillers with long vowels were included. Participants completed a forced-choice identification task involving minimal triplets: singletons, geminates, long vowels (e.g., sasu, sassu, saasu. Results revealed a significant improvement in geminate identification following training, especially for AV; b significant effect of geminate (lowest scores for /s/; c no significant effect of condition; and d no significant improvement for the control group. Most errors were misperceptions of geminates as long vowels. Test of generalization revealed 5% decline in accuracy for AV and 14% for A-only. Geminate production improved significantly (especially for AV based on rater judgments; improvement was greatest for /k/ and smallest for /s/. Most production errors involved substitution of a singleton for a geminate. Post-study interviews produced positive comments on Web-based training. Waveforms increased awareness of durational differences. Results support the effectiveness of auditory-visual input in L2 perception training with transfer to novel stimuli and improved production.

  1. Factors Affecting the Use of Self-Regulated L2 Learning Strategies in Turkish FLE Context (United States)

    Köksal, Dinçay; Dündar, Sinem


    This study aims to investigate the overall self-regulated L2 learning strategy use of L2 learners depending upon the Strategic Self-Regulation (S[superscript 2]R) Model proposed by Oxford (2011), and to examine the relationships between their reported self-regulated L2 strategy use and their personality traits, identity, beliefs about L2 learning,…

  2. Theory of endogenous and exogenous motivation in L2 migration

    Directory of Open Access Journals (Sweden)

    Kambon, Obadele Bakari


    Full Text Available Implied in theories of Second Language Acquisition (SLA is the notion that language learning is analogous to obtaining or acquiring a possession – thus the use of the term ‘acquisition.’ While this interpretation has gone relatively unchallenged in the literature, this article introduces a new analogy whereby language learning is seen as analogous to a process of permanent or semi-permanent migration towards a new socio-linguistic L2 space. As such, a theory of endogenous and exogenous motivation is delineated, entailing a dynamic interplay between internal (primarily psychological and external (primarily sociological push-pull factors. Endogenous and exogenous push-pull factors, together with various other personal factors, contribute to learner decisions to migrate towards, move away from or remain inert with regard to the target language. Further, motivation is framed in the larger theoretical context of causation.

  3. Global magnetohydrodynamic instabilities in the L-2M stellarator

    Energy Technology Data Exchange (ETDEWEB)

    Mikhailov, M. I., E-mail: [National Research Centre Kurchatov Institute (Russian Federation); Shchepetov, S. V., E-mail: [Russian Academy of Sciences, Prokhorov General Physics Institute (Russian Federation); Nührenberg, C.; Nührenberg, J. [Max-Planck-Institut für Plasmaphysik (Germany)


    Analysis of global magnetohydrodynamic (MHD) instabilities in the L-2M stellarator (Prokhorov General Physics Institute, Russian Academy of Sciences) is presented. The properties of free-boundary equilibria states are outlined, the stability conditions for small-scale modes are briefly discussed, and the number of trapped particles is estimated. All the magnetic configurations under study are stable against ballooning modes. It is shown that global ideal internal MHD modes can be found reliably only in Mercier unstable plasmas. In plasma that is stable with respect to the Mercier criterion, global unstable modes that are localized in the vicinity of the free plasma boundary and are not associated with any rational magnetic surface inside the plasma (the so-called peeling modes) can be found. The radial structure of all perturbations under study is almost entirely determined by the poloidal coupling of harmonics. The results of calculations are compared with the available experimental data.


    Directory of Open Access Journals (Sweden)

    Erminia Ardissino


    Full Text Available Il saggio tratta dell'impiego di testi teatrali come fonti di esercizi per l'apprendimento dell'italiano L2/LS. Dopo alcune riflessioni teoriche, si presentano sei proposte di lavoro, con relative soluzioni, adatte a studenti del livello B2-C2 del quadro di riferimento. Si tratta di esercizi ricavati da drammi in un unico atto di Pirandello (La morsa e Lumìe di Sicilia, da Verga (un confronto fra Cavalleria rusticana nella forma drammatica e novellistica, e da Tommaso Landolfi (Ombre. Ogni proposta sfrutta una peculiarità del testo teatrale che si costituisce nell'incontro di dialoghi con didascalie. Anzitutto si tratta di comprendere come si costruiscono i personaggi, quindi di vedere la funzione delle didascalie in relazione al testo, infine di riflettere sulle diverse modalità in cui avvengono i dialoghi, includendo le forme di silenzio. Il testo teatrale appare così molto adatto ad esercizi di lingua, perché mette in gioco le capacità interpretative e immaginative degli studenti, li fa discutere e parlare sulla base delle loro intuizioni.   This paper investigates the use of play scripts as inspiration for Italian L2/FL exercises. After a brief discussion on theory, six project proposals and their solutions, suitable for B2-C2 level students, are presented.  These exercises are based on one-act plays by Pirandello (La Morsa and Lumìe di Sicilia, Verga (a comparison between Cavalleria Rusticana in drama and narrative forms and Tommaso Landolfi (Ombre.  Each project focuses on a specific aspect of the script  and is made up of dialogues with captions. After the way the characters are constructed is investigated, then the function of the captions in relation to the texts is considered, and finally students reflect on the different ways the dialogues are presented, including the pauses. Play scripts lend themselves to language exercises, because they encourage students to use their interpretation skills and imaginations to talk about

  5. Drosophila larvae synthesize the putative oncometabolite L-2-hydroxyglutarate during normal developmental growth. (United States)

    Li, Hongde; Chawla, Geetanjali; Hurlburt, Alexander J; Sterrett, Maria C; Zaslaver, Olga; Cox, James; Karty, Jonathan A; Rosebrock, Adam P; Caudy, Amy A; Tennessen, Jason M


    L-2-hydroxyglutarate (L-2HG) has emerged as a putative oncometabolite that is capable of inhibiting enzymes involved in metabolism, chromatin modification, and cell differentiation. However, despite the ability of L-2HG to interfere with a broad range of cellular processes, this molecule is often characterized as a metabolic waste product. Here, we demonstrate that Drosophila larvae use the metabolic conditions established by aerobic glycolysis to both synthesize and accumulate high concentrations of L-2HG during normal developmental growth. A majority of the larval L-2HG pool is derived from glucose and dependent on the Drosophila estrogen-related receptor (dERR), which promotes L-2HG synthesis by up-regulating expression of the Drosophila homolog of lactate dehydrogenase (dLdh). We also show that dLDH is both necessary and sufficient for directly synthesizing L-2HG and the Drosophila homolog of L-2-hydroxyglutarate dehydrogenase (dL2HGDH), which encodes the enzyme that breaks down L-2HG, is required for stage-specific degradation of the L-2HG pool. In addition, dLDH also indirectly promotes L-2HG accumulation via synthesis of lactate, which activates a metabolic feed-forward mechanism that inhibits dL2HGDH activity and stabilizes L-2HG levels. Finally, we use a genetic approach to demonstrate that dLDH and L-2HG influence position effect variegation and DNA methylation, suggesting that this compound serves to coordinate glycolytic flux with epigenetic modifications. Overall, our studies demonstrate that growing animal tissues synthesize L-2HG in a controlled manner, reveal a mechanism that coordinates glucose catabolism with L-2HG synthesis, and establish the fly as a unique model system for studying the endogenous functions of L-2HG during cell growth and proliferation.

  6. Drosophila larvae synthesize the putative oncometabolite L-2-hydroxyglutarate during normal developmental growth (United States)

    Li, Hongde; Chawla, Geetanjali; Hurlburt, Alexander J.; Sterrett, Maria C.; Zaslaver, Olga; Cox, James; Karty, Jonathan A.; Rosebrock, Adam P.; Caudy, Amy A.


    L-2-hydroxyglutarate (L-2HG) has emerged as a putative oncometabolite that is capable of inhibiting enzymes involved in metabolism, chromatin modification, and cell differentiation. However, despite the ability of L-2HG to interfere with a broad range of cellular processes, this molecule is often characterized as a metabolic waste product. Here, we demonstrate that Drosophila larvae use the metabolic conditions established by aerobic glycolysis to both synthesize and accumulate high concentrations of L-2HG during normal developmental growth. A majority of the larval L-2HG pool is derived from glucose and dependent on the Drosophila estrogen-related receptor (dERR), which promotes L-2HG synthesis by up-regulating expression of the Drosophila homolog of lactate dehydrogenase (dLdh). We also show that dLDH is both necessary and sufficient for directly synthesizing L-2HG and the Drosophila homolog of L-2-hydroxyglutarate dehydrogenase (dL2HGDH), which encodes the enzyme that breaks down L-2HG, is required for stage-specific degradation of the L-2HG pool. In addition, dLDH also indirectly promotes L-2HG accumulation via synthesis of lactate, which activates a metabolic feed-forward mechanism that inhibits dL2HGDH activity and stabilizes L-2HG levels. Finally, we use a genetic approach to demonstrate that dLDH and L-2HG influence position effect variegation and DNA methylation, suggesting that this compound serves to coordinate glycolytic flux with epigenetic modifications. Overall, our studies demonstrate that growing animal tissues synthesize L-2HG in a controlled manner, reveal a mechanism that coordinates glucose catabolism with L-2HG synthesis, and establish the fly as a unique model system for studying the endogenous functions of L-2HG during cell growth and proliferation. PMID:28115720

  7. L2 Learners’ Proficiency Development through Noticing Feedback

    Directory of Open Access Journals (Sweden)

    Seyed Saber Alavi


    Full Text Available This experimental study investigated the relationship between noticing of corrective feedback and L2 development considering the learners’ perspective on error correction. Specifically, it aimed to uncover the noticeability and effectiveness of recasts, prompts, a combination of the two, to determine a relationship between noticing of CF and learning of the past tense. The participants were four groups of college ESL learners (n = 40. Each group was assigned to a treatment condition, but the researcher taught the control group. CF was provided to learners in response to their mistakes in forming the past tense. While noticing of CF was assessed through immediate recall and questionnaire responses, learning outcomes were measured through picture description administered via pre-test, post-test, and delayed post-test design. Learner beliefs about CF were probed by means of a 40-item questionnaire. The results indicated that the noticeability of CF is dependent on the grammatical target it addresses and that the feedback techniques that push learners to self-correct alone or in combination with target exemplars are more effective in. In relation to the learning outcomes, the overall past tense accuracy increased more than that for questions, but there were no significant differences between the groups. Finally, in relation to the beliefs about CF, the participants’ responses centered on the importance of oral CF, recasts as CF technique, prompts as CF technique, and affective consequences of CF, two of which mediated the noticeability of the supplied CF, but none impacted the learning outcomes.

  8. Blogging Identity: How L2 Learners Express Themselves

    Directory of Open Access Journals (Sweden)

    Kiyomi FUJII


    Full Text Available This study discusses language learning and identity, particularly pertaining to intermediate-advanced-level Japanese-language learners, focusing on their target language and identity expression through their interactions with peers and Japanese college students. When learners of Japanese express their identities while interacting with others in their target language, they feel a gap between the self-image they want to present, and the image they are capable of presenting in Japanese (Siegal, 1994, 1995, 1996. Along with adjusting their L1 and L2 usage depending on their interlocutor (Kurata 2007, learners also use different sentence-ending styles depending on the role they want to assume (Cook 2008. By conducting a case study, the present inquiry attempts to address how learners of Japanese express their identities through blog conversations, focusing on their language choice and expressions. Results suggest that participants use the formal endings for self-presentation and projection of their student and classmate identity. However, when expressing emotion some students preferred informal endings, or sentence-final particles.

  9. Analysis of glycosidases activity in Chlamydia trachomatis L2 serotype

    Directory of Open Access Journals (Sweden)

    Dr. Sanjiv Rughooputh


    Full Text Available Chlamydiae are prokaryotic, gram negative, intracellular parasites, causing a number of human diseases with serious sequelae. The exact mechanism of chlamydial attachment and entry into the host cell is still unclear. Chlamydia trachomatis, SA2F (L2 was tested for the activity of glycosidases. Glycosidases are involved in the synthesis and breakdown of cell-wall polysaccharides, and have a pivotal role in attachment to the surface of host cells as well as in the invasion process of other infective agents. For these reasons, glycosidases are likely to provide important information regarding the general behaviour of this bacterium. Ten different glycosides bound to p-nitrophenol (pNP substrate were tested. Assays were performed on lysed and unlysed chlamydial extracts.Our results provided strong evidence for the existence of glycosidase activity in C.trachomatis, strain SA2F peaking at pH 5.0 and pH 7.5-8.0 There was a high enzymatic activity against p-NPa mannopyranoside and p-NP b-N acetylglucosamine with a recovery of 88% suggesting that the enzymes were present on the bacterial surface. Activity against these sugars, which form part of either the extracellular filler or in endoplasmic reticulum may suggest of a possible mechanism of cellular invasion.

  10. L2 Spelling Errors in Italian Children with Dyslexia. (United States)

    Palladino, Paola; Cismondo, Dhebora; Ferrari, Marcella; Ballagamba, Isabella; Cornoldi, Cesare


    The present study aimed to investigate L2 spelling skills in Italian children by administering an English word dictation task to 13 children with dyslexia (CD), 13 control children (comparable in age, gender, schooling and IQ) and a group of 10 children with an English learning difficulty, but no L1 learning disorder. Patterns of difficulties were examined for accuracy and type of errors, in spelling dictated short and long words (i.e. disyllables and three syllables). Notably, CD were poor in spelling English words. Furthermore, their errors were mainly related with phonological representation of words, as they made more 'phonologically' implausible errors than controls. In addition, CD errors were more frequent for short than long words. Conversely, the three groups did not differ in the number of plausible ('non-phonological') errors, that is, words that were incorrectly written, but whose reading could correspond to the dictated word via either Italian or English rules. Error analysis also showed syllable position differences in the spelling patterns of CD, children with and English learning difficulty and control children. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  11. Wavelet Decomposition Method for $L_2/$/TV-Image Deblurring

    KAUST Repository

    Fornasier, M.


    In this paper, we show additional properties of the limit of a sequence produced by the subspace correction algorithm proposed by Fornasier and Schönlieb [SIAM J. Numer. Anal., 47 (2009), pp. 3397-3428 for L 2/TV-minimization problems. An important but missing property of such a limiting sequence in that paper is the convergence to a minimizer of the original minimization problem, which was obtained in [M. Fornasier, A. Langer, and C.-B. Schönlieb, Numer. Math., 116 (2010), pp. 645-685 with an additional condition of overlapping subdomains. We can now determine when the limit is indeed a minimizer of the original problem. Inspired by the work of Vonesch and Unser [IEEE Trans. Image Process., 18 (2009), pp. 509-523], we adapt and specify this algorithm to the case of an orthogonal wavelet space decomposition for deblurring problems and provide an equivalence condition to the convergence of such a limiting sequence to a minimizer. We also provide a counterexample of a limiting sequence by the algorithm that does not converge to a minimizer, which shows the necessity of our analysis of the minimizing algorithm. © 2012 Society for Industrial and Applied Mathematics.

  12. Recent results of ECRH experiments on L-2M stellarator

    International Nuclear Information System (INIS)

    Shchepetov, S.V.; Akulina, D.K.; Batanov, G.M.


    Results are reported from experimental study of ECH heated plasma in the L-2M stellarator with special emphasis on studying the turbulent processes. It is shown that the total plasma energy at fixed total heating power is strongly dependent on the plasma position. Visible degradation of plasma confinement is observed for the inward shifted magnetic configurations where the stability conditions of ideal interchange MHD modes are violated. However, even in this case the situation can be improved by decreasing the average radius of the plasma boundary with the help of graphite limiter resulting in the increase of the Shafranov shift of magnetic surfaces and deepening of the magnetic well due to the effect of self-stabilization. This in turn causes stabilization of ideal MHD interchange modes and visible increase in plasma energy and volume average value of beta. Statistical properties of turbulence was studied both for the central part of the plasma column and for the plasma edge. It is shown that one of the critical factors determining the coherent structures and turbulent fluxes in the edge plasma is the radial electric field. (author)

  13. Listening is my bugbear: Why Iranian L2 learners keep underperforming in the listening module

    Directory of Open Access Journals (Sweden)

    Novid Armiun


    Full Text Available This paper shares the results of a study into the way Iranian TEF or TEFAQ candidates treat the listening comprehension as a skill as well as their awareness and exploitation of metacognitive strategies while listening to an audio document. A Persian translation of the Metacognitive Awareness Listening Questionnaire (MALQ was used in addition to another questionnaire specifically developed for this research in order to gage how important candidates think listening in L2 is compared to the other skills, how much time they spent on practicing listening, and how often they take advantage of authentic documents to improve their listening. Not only did the results show an underestimation of the listening comprehension skill by the majority of Iranian L2 learners, but they also pointed to significant differences in the way men and women exercised their ears and treated the incoming audio stream. The paper concludes that learners’ awareness of listening strategies needs to be raised through classroom instruction and frequent exploitation of authentic documents outside the classroom setting should be encouraged.

  14. L2 willingness to communicate (WTC and international posture in the Polish educational context

    Directory of Open Access Journals (Sweden)

    Anna Mystkowska-Wiertelak


    Full Text Available Speaking, the language skill whose mastering appears to be the ultimate aim of every attempt at learning a foreign language, constitutes a formidable challenge. Apart from involving the online interaction of complex processes of conceptualization, formulation, articulation and monitoring (Levelt, 1989, it appears prone to numerous psychological and social influences that, being difficult to control, may consistently hinder development. One of such factors, closely related to the concept of anxiety, is L2 willingness to communicate (WTC, called “the most immediate determinant of L2 use” (Clement, Baker, & MacIntyre, 2003, p. 191. Perceived as either a personality trait or/and a context-related feature, WTC seems capable of accounting for a person’s first and second language communication. Interestingly it can be related to the learner’s disposition towards the target language culture, general interest in international affairs, willingness to travel and sustain contacts with speakers of other languages, which, defined as international posture (Yashima, 2002, serves as a strong predictor of success in language learning. The present paper reports the results of a survey conducted among 111 students of English, in the majority prospect teachers of English. The aim was to establish the degree of correlation between their international posture and WTC. The results do not corroborate the outcomes of other studies performed in the field (cf. Yashima, 2002, 2009, which might point to the unique characteristics of the Polish educational context.

  15. The Effects of L2C Signal Tracking on High-Precision Carrier Phase GPS Positioning (United States)

    Berglund, H.; Blume, F.; Estey, L. H.; Borsa, A. A.


    In 2005, the L2C signal was introduced to improve the accuracy, tracking and redundancy of the GPS system for civilian users. The L2C signal also provides improved SNR data when compared with the L2P(Y) legacy signal, comparable to that of the L1 C/A-code, which allows for better tracking at lower elevations. With the recent launch of the first block II-F satellite (SVN62/PRN25), there are 8 healthy satellites broadcasting L2C signals, or 25% of the constellation. However, GNSS network operators such as the UNAVCO Plate Boundary Observatory (PBO) have been hesitant to use the new signal as it is not well determined how tracking and logging L2C could affect the positions derived from L2 carrier phase measurements for a given receiver. The L2C carrier phase is in quadrature (90° out of phase) with the L2P(Y) phase that has been used by high-precision positioning software since the beginning of GPS. To complicate matters further, some receiver manufacturers (e.g. Trimble) correct for this when logging L2C phase while others (e.g. Topcon) do not. The L2C capability of receivers currently in widespread use in permanent networks can depend on firmware as well as hardware; in some cases receivers can simultaneously track L2C and L2P(Y) phases and some can track only one or the other, and the resulting observation files can depend on how individual operators configure the devices. In cases where both L2C and L2P(Y) are logged simultaneously, translation software (such as UNAVCO’s teqc) must be used carefully in order to select which L2 observation is written to RINEX (2.11) and used in positioning. Modifications were recently made to teqc to eliminate potential confusion in that part of the process; if L2C code observations appear in a RINEX (2.11) file produced by teqc, the L2 phase and S2 SNR observations were from the L2C carrier for those satellites. To date L2C analyses have been restricted to special applications such as snow depth and soil moisture using SNR data

  16. New Developments in the SCIAMACHY L2 Ground Processor (United States)

    Gretschany, Sergei; Lichtenberg, Günter; Meringer, Markus; Theys, Nicolas; Lerot, Christophe; Liebing, Patricia; Noel, Stefan; Dehn, Angelika; Fehr, Thorsten


    SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric ChartographY) aboard ESA's environmental satellite ENVISAT observed the Earth's atmosphere in limb, nadir, and solar/lunar occultation geometries covering the UV-Visible to NIR spectral range. It is a joint project of Germany, the Netherlands and Belgium and was launched in February 2002. SCIAMACHY doubled its originally planned in-orbit lifetime of five years before the communication to ENVISAT was severed in April 2012, and the mission entered its post-operational phase. In order to preserve the best quality of the outstanding data recorded by SCIAMACHY, data processors are still being updated. This presentation will highlight three new developments that are currently being incorporated into the forthcoming Version 7 of ESA's operational Level 2 processor: 1. Tropospheric BrO, a new retrieval based on the scientific algorithm of (Theys et al., 2011). This algorithm had been originally developed for the GOME-2 sensor and later adapted for SCIAMACHY. The main principle of the new algorithm is to utilize BrO total columns (already an operational product) and split them into stratospheric VCDstrat and tropospheric VCDtrop fractions. BrO VCDstrat is determined from a climatological approach, driven by SCIAMACHY O3 and NO2 observations. VCDtrop is then determined simply as a difference: VCDtrop = VCDtotal - VCDstrat. 2. Improved cloud flagging using limb measurements (Liebing, 2015). Limb cloud flags are already part of the SCIAMACHY L2 product. They are currently calculated employing the scientific algorithm developed by (Eichmann et al., 2015). Clouds are categorized into four types: water, ice, polar stratospheric and noctilucent clouds. High atmospheric aerosol loadings, however, often lead to spurious cloud flags, when aerosols had been misidentified as clouds. The new algorithm will better discriminate between aerosol and clouds. It will also have a higher sensitivity w.r.t. thin clouds. 3. A new

  17. MODIS/Aqua Clouds 5-Min L2 Swath 1km and 5km V006 (United States)

    National Aeronautics and Space Administration — The MODIS/Aqua Clouds 5-Min L2 Swath 1km and 5km (MYD06_L2) product consists of cloud optical and physical parameters. These parameters are derived using remotely...

  18. MODIS/Aqua Aerosol 5-Min L2 Swath 10km V006 (United States)

    National Aeronautics and Space Administration — The MODIS/Aqua Aerosol 5-Min L2 Swath 10km (MYD04_L2) product continues to provide full global coverage of aerosol properties from the Dark Target (DT) and Deep Blue...

  19. LOFT/L2-5, Loss of Fluid Test, 3. NRC L2 Large Break LOCA Experiment

    International Nuclear Information System (INIS)


    1 - Description of test facility: The LOFT Integral Test Facility is a scale model of a LPWR. The intent of the facility is to model the nuclear, thermal-hydraulic phenomena which would take place in a LPWR during a LOCA. The general philosophy in scaling coolant volumes and flow areas in LOFT was to use the ratio of the LOFT core [50 MW(t)] to a typical LPWR core [3000 MW(t)]. For some components, this factor is not applied; however, it is used as extensively as practical. In general, components used in LOFT are similar in design to those of a LPWR. Because of scaling and component design, the LOFT LOCA is expected to closely model a LPWR LOCA. 2 - Description of test: This experiment was the third of the NRC L2 Series of nuclear large Break LOCA experiments, conducted on 16 June 1981. It simulated a 100% cold leg break with a maximum heat generation of 40 kW/m and rapid pump coast down

  20. LOFT/L2-3, Loss of Fluid Test, 2. NRC L2 Large Break LOCA Experiment

    International Nuclear Information System (INIS)


    1 - Description of test facility: The LOFT Integral Test Facility is a scale model of a LPWR. The intent of the facility is to model the nuclear, thermal-hydraulic phenomena which would take place in a LPWR during a LOCA. The general philosophy in scaling coolant volumes and flow areas in LOFT was to use the ratio of the LOFT core [50 MW(t)] to a typical LPWR core [3000 MW(t)]. For some components, this factor is not applied; however, it is used as extensively as practical. In general, components used in LOFT are similar in design to those of a LPWR. Because of scaling and component design, the LOFT LOCA is expected to closely model a LPWR LOCA. 2 - Description of test: This experiment was the second of the NRC L2 Series of nuclear large Break LOCA experiments, and was conducted on 12 May 1979. It simulated a 100% cold leg break with a maximum heat generation of 39 kW/m

  1. Linguistic dimensions of l2 accentedness and comprehensibility vary across speaking tasks


    Crowther, D.; Trofimovich, P.; Isaacs, T.; Saito, Kazuya


    This study critically examined the previously reported partial independence between second language (L2) accentedness (degree to which L2 speech differs from the target variety) and comprehensibility (ease of understanding). In prior work, comprehensibility was linked to multiple linguistic dimensions of L2 speech (phonology, fluency, lexis, grammar) whereas accentedness was narrowly associated with L2 phonology. However, these findings stemmed from a single task (picture narrative), suggesti...

  2. Formation Control of the MAXIM L2 Libration Orbit Mission (United States)

    Folta, David; Hartman, Kate; Howell, Kathleen; Marchand, Belinda


    The Micro-Arcsecond X-ray Imaging Mission (MAXIM), a proposed concept for the Structure and Evolution of the Universe (SEU) Black Hole Imager mission, is designed to make a ten million-fold improvement in X-ray image clarity of celestial objects by providing better than 0.1 micro-arcsecond imaging. Currently the mission architecture comprises 25 spacecraft, 24 as optics modules and one as the detector, which will form sparse sub-apertures of a grazing incidence X-ray interferometer covering the 0.3-10 keV bandpass. This formation must allow for long duration continuous science observations and also for reconfiguration that permits re-pointing of the formation. To achieve these mission goals, the formation is required to cooperatively point at desired targets. Once pointed, the individual elements of the MAXIM formation must remain stable, maintaining their relative positions and attitudes below a critical threshold. These pointing and formation stability requirements impact the control and design of the formation. In this paper, we provide analysis of control efforts that are dependent upon the stability and the configuration and dimensions of the MAXIM formation. We emphasize the utilization of natural motions in the Lagrangian regions to minimize the control efforts and we address continuous control via input feedback linearization (IFL). Results provide control cost, configuration options, and capabilities as guidelines for the development of this complex mission.

  3. Do L2 Writing Courses Affect the Improvement of L1 Writing Skills via Skills Transfer from L2 to L1? (United States)

    Gonca, Altmisdort


    This study investigates the relationship of second language (L2) writing skills proficiency with the first language (L1) writing skills, in light of the language transfer. The study aims to analyze the positive effects of L2 writing proficiency on L1 writing proficiency. Forty native Turkish-speaking university students participated in the study.…

  4. Learner Variables Important for Success in L2 Listening Comprehension in French Immersion Classrooms (United States)

    Vandergrift, Larry; Baker, Susan C.


    Listening comprehension, which is relatively straightforward for native language (L1) speakers, is often frustrating for second language (L2) learners. Listening comprehension is important to L2 acquisition, but little is known about the variables that influence the development of L2 listening skills. The goal of this study was to determine which…

  5. Factors Affecting Grammatical and Lexical Complexity of Long-Term L2 Speakers' Oral Proficiency (United States)

    Lahmann, Cornelia; Steinkrauss, Rasmus; Schmid, Monika S.


    There remains considerable disagreement about which factors drive second language (L2) ultimate attainment. Age of onset (AO) appears to be a robust factor, lending support to theories of maturational constraints on L2 acquisition. The present study is an investigation of factors that influence grammatical and lexical complexity at the stage of L2

  6. Investigating the Role of Multiple Intelligences in Determining Vocabulary Learning Strategies for L2 Learners (United States)

    Sistani, Mahsa; Hashemian, Mahmood


    This study, first, examined whether there was any relationship between Iranian L2 learners' vocabulary learning strategies (VLSs), on the one hand, and their multiple intelligences (MI) types, on the other hand. In so doing, it explored the extent to which MI would predict L2 learners' VLSs. To these ends, 40 L2 learners from Isfahan University of…

  7. L1 and L2 Strategy Use in Reading Comprehension of Chinese EFL Readers (United States)

    Tsai, Yea-Ru; Ernst, Cheryl; Talley, Paul C.


    This study revealed the relationship between L1 (Mandarin Chinese) and L2 (English) strategy use in L2 reading comprehension by focusing on the correlation of L1 reading ability, L2 proficiency and employed reading strategies. The participants, 222 undergraduates learning English as a foreign language (EFL), were classified into skilled and…

  8. Learning L2 German vocabulary through reading: the effect of three enhancement techniques compared

    NARCIS (Netherlands)

    Peters, E.; Hulstijn, J.H.; Sercu, L.; Lutjeharms, M.


    This study investigated three techniques designed to increase the chances that second language (L2) readers look up and learn unfamiliar words during and after reading an L2 text. Participants in the study, 137 college students in Belgium (L1 = Dutch, L2 = German), were randomly assigned to one of

  9. Investigating an Innovative Computer Application to Improve L2 Word Recognition from Speech (United States)

    Matthews, Joshua; O'Toole, John Mitchell


    The ability to recognise words from the aural modality is a critical aspect of successful second language (L2) listening comprehension. However, little research has been reported on computer-mediated development of L2 word recognition from speech in L2 learning contexts. This report describes the development of an innovative computer application…

  10. A Prerequisite to L1 Homophone Effects in L2 Spoken-Word Recognition (United States)

    Nakai, Satsuki; Lindsay, Shane; Ota, Mitsuhiko


    When both members of a phonemic contrast in L2 (second language) are perceptually mapped to a single phoneme in one's L1 (first language), L2 words containing a member of that contrast can spuriously activate L2 words in spoken-word recognition. For example, upon hearing cattle, Dutch speakers of English are reported to experience activation…

  11. Phonological Memory and the Acquisition of Grammar in Child L2 Learners (United States)

    Verhagen, Josje; Leseman, Paul; Messer, Marielle


    Previous studies show that second language (L2) learners with large phonological memory spans outperform learners with smaller memory spans on tests of L2 grammar. The current study investigated the relationship between phonological memory and L2 grammar in more detail than has been done earlier. Specifically, we asked how phonological memory…

  12. CALL--Enhanced L2 Listening Skills--Aiming for Automatization in a Multimedia Environment (United States)

    Mayor, Maria Jesus Blasco


    Computer Assisted Language Learning (CALL) and L2 listening comprehension skill training are bound together for good. A neglected macroskill for decades, developing listening comprehension skill is now considered crucial for L2 acquisition. Thus this paper makes an attempt to offer latest information on processing theories and L2 listening…

  13. Semantic Categorization of Placement Verbs in L1 and L2 Danish and Spanish (United States)

    Cadierno, Teresa; Ibarretxe-Antuñano, Iraide; Hijazo-Gascón, Alberto


    This study investigates semantic categorization of the meaning of placement verbs by Danish and Spanish native speakers and two groups of intermediate second language (L2) learners (Danish learners of L2 Spanish and Spanish learners of L2 Danish). Participants described 31 video clips picturing different types of placement events. Cluster analyses…

  14. Seeking out Challenges to Develop L2 Self-Confidence: A Language Learner's Journey to Proficiency (United States)

    Edwads, Emily; Roger, Peter Stewart


    As one constituent of second language (L2) motivation, L2 "self-­confidence" has been shown to be a significant predictor of language proficiency. More recently, L2 self-­confidence has been studied as part of the "willingness to communicate" (WTC) construct. Less is known, however, about the processes by which learners develop…

  15. Deep Processing of Long-Distance Dependencies in L2 English: The Case of Anaphora (United States)

    Wang, Yi-Ting


    Since the seminal work of Alan Juffs, second language (L2) sentence processing has become a central research topic in the field of L2 acquisition. Beyond a general hunger for new data offered by new experimental techniques and designs, intellectual concerns with system-wide understanding of first-language (L1)-L2 differences extended to the…

  16. L2 Motivational Self-System and Self-Efficacy: A Quantitative Survey-Based Study (United States)

    Roshandel, Javad; Ghonsooly, Behzad; Ghanizadeh, Afsaneh


    The present study explored English as a foreign language (EFL) students' motivation and self-efficacy. This is accomplished by incorporating the ten subfactors of L2 motivational self-system namely; criterion measures, ideal L2 self, ought-to L2 self, family influence, instrumentality promotion, instrumentality prevention, attitudes towards…

  17. Spectral L2/L1 norm: A new perspective for spectral kurtosis for characterizing non-stationary signals (United States)

    Wang, Dong


    Thanks to the great efforts made by Antoni (2006), spectral kurtosis has been recognized as a milestone for characterizing non-stationary signals, especially bearing fault signals. The main idea of spectral kurtosis is to use the fourth standardized moment, namely kurtosis, as a function of spectral frequency so as to indicate how repetitive transients caused by a bearing defect vary with frequency. Moreover, spectral kurtosis is defined based on an analytic bearing fault signal constructed from either a complex filter or Hilbert transform. On the other hand, another attractive work was reported by Borghesani et al. (2014) to mathematically reveal the relationship between the kurtosis of an analytical bearing fault signal and the square of the squared envelope spectrum of the analytical bearing fault signal for explaining spectral correlation for quantification of bearing fault signals. More interestingly, it was discovered that the sum of peaks at cyclic frequencies in the square of the squared envelope spectrum corresponds to the raw 4th order moment. Inspired by the aforementioned works, in this paper, we mathematically show that: (1) spectral kurtosis can be decomposed into squared envelope and squared L2/L1 norm so that spectral kurtosis can be explained as spectral squared L2/L1 norm; (2) spectral L2/L1 norm is formally defined for characterizing bearing fault signals and its two geometrical explanations are made; (3) spectral L2/L1 norm is proportional to the square root of the sum of peaks at cyclic frequencies in the square of the squared envelope spectrum; (4) some extensions of spectral L2/L1 norm for characterizing bearing fault signals are pointed out.

  18. Analysis of Discrete L2 Projection on Polynomial Spaces with Random Evaluations

    KAUST Repository

    Migliorati, Giovanni


    We analyze the problem of approximating a multivariate function by discrete least-squares projection on a polynomial space starting from random, noise-free observations. An area of possible application of such technique is uncertainty quantification for computational models. We prove an optimal convergence estimate, up to a logarithmic factor, in the univariate case, when the observation points are sampled in a bounded domain from a probability density function bounded away from zero and bounded from above, provided the number of samples scales quadratically with the dimension of the polynomial space. Optimality is meant in the sense that the weighted L2 norm of the error committed by the random discrete projection is bounded with high probability from above by the best L∞ error achievable in the given polynomial space, up to logarithmic factors. Several numerical tests are presented in both the univariate and multivariate cases, confirming our theoretical estimates. The numerical tests also clarify how the convergence rate depends on the number of sampling points, on the polynomial degree, and on the smoothness of the target function. © 2014 SFoCM.

  19. Analysis of Discrete L2 Projection on Polynomial Spaces with Random Evaluations

    KAUST Repository

    Migliorati, Giovanni; Nobile, Fabio; von Schwerin, Erik; Tempone, Raul


    We analyze the problem of approximating a multivariate function by discrete least-squares projection on a polynomial space starting from random, noise-free observations. An area of possible application of such technique is uncertainty quantification for computational models. We prove an optimal convergence estimate, up to a logarithmic factor, in the univariate case, when the observation points are sampled in a bounded domain from a probability density function bounded away from zero and bounded from above, provided the number of samples scales quadratically with the dimension of the polynomial space. Optimality is meant in the sense that the weighted L2 norm of the error committed by the random discrete projection is bounded with high probability from above by the best L∞ error achievable in the given polynomial space, up to logarithmic factors. Several numerical tests are presented in both the univariate and multivariate cases, confirming our theoretical estimates. The numerical tests also clarify how the convergence rate depends on the number of sampling points, on the polynomial degree, and on the smoothness of the target function. © 2014 SFoCM.

  20. An Introduction of Zoltán D?rnyei's L2 Motivational Theories%An Introduction of Zoltán Dörnyei's L2 Motivational Theories

    Institute of Scientific and Technical Information of China (English)

    王晓磊; 周密


    Professor Zoltán D?rnyei is an influential researcher of L2 learning motivation. Since 1990s, he put forward several important L2 learning motivational theories and made special contribution to this field. This paper introduces his four L2 learn-ing motivational theories:1)Three-level framework of L2 motivation;2) Process model of L2 motivation;3)The L2 Motivation-al Self System;4) Directed Motivational Currents (DMC).

  1. Points of Transition: Understanding the Constructed Identities of L2 Learners/Users across Time and Space (United States)

    Adawu, Anthony; Martin-Beltran, Melinda


    Using sociocultural and poststructuralist theoretical lenses, this study examines the narrative construction of language-learner identity across time and space. We applied cross-narrative methodologies to analyze language-learning autobiographies and interview data from three English users who had recently transitioned to a U.S. context for…

  2. The RNA-binding protein, ZFP36L2, influences ovulation and oocyte maturation.

    Directory of Open Access Journals (Sweden)

    Christopher B Ball

    Full Text Available ZFP36L2 protein destabilizes AU-rich element-containing transcripts and has been implicated in female fertility. In the C57BL/6NTac mouse, a mutation in Zfp36l2 that results in the decreased expression of a form of ZFP36L2 in which the 29 N-terminal amino acid residues have been deleted, ΔN-ZFP36L2, leads to fertilized eggs that arrest at the two-cell stage. Interestingly, homozygous ΔN-Zfp36l2 females in the C57BL/6NTac strain release 40% fewer eggs than the WT littermates (Ramos et al., 2004, suggesting an additional defect in ovulation and/or oocyte maturation. Curiously, the same ΔN-Zfp36l2 mutation into the SV129 strain resulted in anovulation, prompting us to investigate a potential problem in ovulation and oocyte maturation. Remarkably, only 20% of ΔN-Zfp36l2 oocytes in the 129S6/SvEvTac strain matured ex vivo, suggesting a defect on the oocyte meiotic maturation process. Treatment of ΔN-Zfp36l2 oocytes with a PKA inhibitor partially rescued the meiotic arrested oocytes. Furthermore, cAMP levels were increased in ΔN-Zfp36l2 oocytes, linking the cAMP/PKA pathway and ΔN-Zfp36l2 with meiotic arrest. Since ovulation and oocyte maturation are both triggered by LHR signaling, the downstream pathway was investigated. Adenylyl cyclase activity was increased in ΔN-Zfp36l2 ovaries only upon LH stimulation. Moreover, we discovered that ZFP36L2 interacts with the 3'UTR of LHR mRNA and that decreased expression levels of Zfp36l2 correlates with higher levels of LHR mRNA in synchronized ovaries. Furthermore, overexpression of ZFP36L2 decreases the endogenous expression of LHR mRNA in a cell line. Therefore, we propose that lack of the physiological down regulation of LHR mRNA levels by ZFP36L2 in the ovaries is associated with anovulation and oocyte meiotic arrest.

  3. Learning to perceive and recognize a second language: the L2LP model revised. (United States)

    van Leussen, Jan-Willem; Escudero, Paola


    We present a test of a revised version of the Second Language Linguistic Perception (L2LP) model, a computational model of the acquisition of second language (L2) speech perception and recognition. The model draws on phonetic, phonological, and psycholinguistic constructs to explain a number of L2 learning scenarios. However, a recent computational implementation failed to validate a theoretical proposal for a learning scenario where the L2 has less phonemic categories than the native language (L1) along a given acoustic continuum. According to the L2LP, learners faced with this learning scenario must not only shift their old L1 phoneme boundaries but also reduce the number of categories employed in perception. Our proposed revision to L2LP successfully accounts for this updating in the number of perceptual categories as a process driven by the meaning of lexical items, rather than by the learners' awareness of the number and type of phonemes that are relevant in their new language, as the previous version of L2LP assumed. Results of our simulations show that meaning-driven learning correctly predicts the developmental path of L2 phoneme perception seen in empirical studies. Additionally, and to contribute to a long-standing debate in psycholinguistics, we test two versions of the model, with the stages of phonemic perception and lexical recognition being either sequential or interactive. Both versions succeed in learning to recognize minimal pairs in the new L2, but make diverging predictions on learners' resulting phonological representations. In sum, the proposed revision to the L2LP model contributes to our understanding of L2 acquisition, with implications for speech processing in general.

  4. Deficiency of C5L2 increases macrophage infiltration and alters adipose tissue function in mice.

    Directory of Open Access Journals (Sweden)

    Danny Gauvreau

    Full Text Available BACKGROUND: Obesity is considered as a systemic chronic low grade inflammation characterized by increased serum pro-inflammatory proteins and accumulation of macrophages within white adipose tissue (WAT of obese patients. C5L2, a 7-transmembrane receptor, serves a dual function, binding the lipogenic hormone acylation stimulating protein (ASP, and C5a, involved in innate immunity. AIM: We evaluated the impact of C5L2 on macrophage infiltration in WAT of wildtype (Ctl and C5L2 knock-out (C5L2(-/- mice over 6, 12 and 24 weeks on a chow diet and moderate diet-induced obesity (DIO conditions. RESULTS: In Ctl mice, WAT C5L2 and C5a receptor mRNA increased (up to 10-fold both over time and with DIO. By contrast, in C5L2(-/-, there was no change in C5aR in WAT. C5L2(-/- mice displayed higher macrophage content in WAT, varying by time, fat depot and diet, associated with altered systemic and WAT cytokine patterns compared to Ctl mice. However, in all cases, the M1 (pro- vs M2 (anti-inflammatory macrophage proportion was unchanged but C5L2(-/- adipose tissue secretome appeared to be more chemoattractant. Moreover, C5L2(-/- mice have increased food intake, increased WAT, and altered WAT lipid gene expression, which is reflected systemically. Furthermore, C5L2(-/- mice have altered glucose/insulin metabolism, adiponectin and insulin signalling gene expression in WAT, which could contribute to development of insulin resistance. CONCLUSION: Disruption of C5L2 increases macrophage presence in WAT, contributing to obesity-associated pathologies, and further supports a dual role of complement in WAT. Understanding this effect of the complement system pathway could contribute to targeting treatment of obesity and its comorbidities.

  5. Tipping Point

    Medline Plus

    Full Text Available ... en español Blog About OnSafety CPSC Stands for Safety The Tipping Point Home > 60 Seconds of Safety (Videos) > The Tipping Point The Tipping Point by ... danger death electrical fall furniture head injury product safety television tipover tv Watch the video in Adobe ...

  6. Vibrational spectroscopic and theoretical study of 3,5-dimethyl-1-thiocarboxamide pyrazole (L) and the complexes Co2L2Cl4, Cu2L2Cl4 and Cu2L2Br2

    International Nuclear Information System (INIS)

    Nemcsok, Denes; Kovacs, Attila; Szecsenyi, Katalin Meszaros; Leovac, Vukadin M.


    In the present paper we report a joint experimental and theoretical study of 3,5-dimethyl-1-thiocarboxamide pyrazole (L) and its complexes Co 2 L 2 Cl 4 , Cu 2 L 2 Cl 4 and Cu 2 L 2 Br 2 . DFT computations were used to model the structural and bonding properties of the title compounds as well as to derive a reliable force field for the normal coordinate analysis of L. The computations indicated the importance of hydrogen bonding interactions in stabilising the global minimum structures on the potential energy surfaces. In contrast to the S-bridged binuclear Cu 2 L 2 Br 2 complex found in the crystal, our computations predicted the formation of (CuLBr) 2 dimers in the isolated state stabilized by very strong (53 kJ/mol) N-H...Br hydrogen bonding interactions. On the basis of FT-IR and FT-Raman experiments and the DFT-derived scaled quantum mechanical force field we carried out a complete normal coordinate analysis of L. The FT-IR spectra of the three complexes were interpreted using the present assignment of L, literature data and computed results

  7. Grapho-Morphological Awareness in Spanish L2 Reading: How Do Learners Use This Metalinguistic Skill? (United States)

    Miguel, Nausica Marcos


    This paper contributes to the literature on the transferability of grapho-morphological awareness (GMA) for second language (L2) learners by analysing L2 learners' knowledge of morphology in reading. GMA helps readers to identify grammatical categories, infer meanings of unfamiliar words, and access stored lexical information. Previous research…

  8. Translation and Short-Term L2 Vocabulary Retention: Hindrance or Help? (United States)

    Hummel, Kirsten M.


    This study addresses the role that active translation may have in second language (L2) vocabulary learning. Some research suggests that translation might be an effective cognitive strategy for L2 vocabulary learning. Participants were 191 native French-speaking students enrolled in a TESL (Teaching English as a Second Language) program.The study…

  9. L2-Harmonic Forms on Incomplete Riemannian Manifolds with Positive Ricci Curvature

    Directory of Open Access Journals (Sweden)

    Junya Takahashi


    Full Text Available We construct an incomplete Riemannian manifold with positive Ricci curvature that has non-trivial L 2 -harmonic forms and on which the L 2 -Stokes theorem does not hold. Therefore, a Bochner-type vanishing theorem does not hold for incomplete Riemannian manifolds.

  10. Factors Affecting Grammatical and Lexical Complexity of Long-Term L2 Speakers’ Oral Proficiency

    NARCIS (Netherlands)

    Lahmann, Cornelia; Steinkrauss, Rasmus; Schmid, Monika


    There remains considerable disagreement about which factors drive second language (L2) ultimate attainment. Age of onset (AO) appears to be a robust factor, lending support to theories of maturational constraints on L2 acquisition. The present study is an investigation of factors that influence

  11. Shared Features of L2 Writing: Intergroup Homogeneity and Text Classification (United States)

    Crossley, Scott A.; McNamara, Danielle S.


    This study investigates intergroup homogeneity within high intermediate and advanced L2 writers of English from Czech, Finnish, German, and Spanish first language backgrounds. A variety of linguistic features related to lexical sophistication, syntactic complexity, and cohesion were used to compare texts written by L1 speakers of English to L2

  12. L2-proficiency-dependent laterality shift in structural connectivity of brain language pathways

    NARCIS (Netherlands)

    Xiang, H.; Leeuwen, T.M. van; Dediu, D.; Roberts, L.; Norris, D.; Hagoort, P.


    Diffusion tensor imaging (DTI) and a longitudinal language learning approach were applied to investigate the relationship between the achieved second language (L2) proficiency during L2 learning and the reorganization of structural connectivity between core language areas. Language proficiency tests

  13. Toward a Tripartite Model of L2 Reading Strategy Use, Motivations, and Learner Beliefs (United States)

    Matsumoto, Hiroyuki; Hiromori, Tomohito; Nakayama, Akira


    The present study proposes a tripartite model of L2 reading strategy use, reading motivations, and general learner beliefs by examining the relationships among them in an L2 context. Reading strategy instruction was performed for 360 first-year university students enrolled in a reading-based course, in expectation of affecting their motivations…

  14. Listening Strategies in the L2 Classroom: More Practice, Less Testing (United States)

    Aponte-de-Hanna, Cecilia


    This paper looks at the history of listening strategies development from the first studies on strategies used by L2 learners to the most current studies specific to L2 listening, and how this theory can be incorporated into classroom teaching that fosters practice, not testing. This paper also examines the type of needs analysis and diagnostic…

  15. The acquisition of grammatical gender in L2 German by learners ...

    African Journals Online (AJOL)

    The study reported in this paper investigated the adult L2 acquisition of grammatical gender in German by first language (L1) speakers of Afrikaans, English and Italian, respectively. The aim of the study was to determine how similarities and differences between the L1 and L2 in terms of grammatical gender affect the ...

  16. Crystal Structures of Intermediates in the Dehalogenation of Haloalkanoates by L-2-Haloacid Dehalogenase

    NARCIS (Netherlands)

    Ridder, Ivo S.; Rozeboom, Henriëtte J.; Kalk, Kor H.; Dijkstra, Bauke W.


    The L-2-haloacid dehalogenase from the 1,2-dichloroethane-degrading bacterium Xanthobacter autotrophicus GJ10 catalyzes the hydrolytic dehalogenation of small L-2-haloalkanoates to their corresponding D-2-hydroxyalkanoates, with inversion of the configuration at the C2 atom. The structure of the

  17. The Role of L2 Learner Goal Differences in Task-Generated Oral Production (United States)

    Ben Maad, Mohamed Ridha


    In light of the growing interest in the cognitive approach to task in second language (L2) research, comparatively little has been done to examine such effect over time and the role of individual differences (IDs). The present study was designed to verify some longitudinal evidence for the role of tasks in L2 production and whether IDs, in the…

  18. Beyond barriers : Complexity, accuracy, and fluency in long-term L2 speakers' speech

    NARCIS (Netherlands)

    Lahmann, Cornelia Milli Marie Antonia


    It remains to be a puzzling question why some people are more successful in learning a second language (L2) than others and under which conditions. In my dissertation I studied the effects of several factors, including the starting age of learning a L2, the amount of continued exposure to the first

  19. Cognitive Factors Contributing to Chinese EFL Learners' L2 Writing Performance in Timed Essay Writing (United States)

    Lu, Yanbin


    This study investigated cognitive factors that might influence Chinese EFL learners' argumentative essay writing in English. The factors that were explored included English (L2) language proficiency, Chinese (L1) writing ability, genre knowledge, use of writing strategies, and working memory capacity in L1 and L2. Data were collected from 136…

  20. L2 Word Recognition: Influence of L1 Orthography on Multi-Syllabic Word Recognition (United States)

    Hamada, Megumi


    L2 reading research suggests that L1 orthographic experience influences L2 word recognition. Nevertheless, the findings on multi-syllabic words in English are still limited despite the fact that a vast majority of words are multi-syllabic. The study investigated whether L1 orthography influences the recognition of multi-syllabic words, focusing on…

  1. A Review of Multimedia Glosses and Their Effects on L2 Vocabulary Acquisition in CALL Literature (United States)

    Mohsen, Mohammed Ali; Balakumar, M.


    This article reviews the literature of multimedia glosses in computer assisted language learning (CALL) and their effects on L2 vocabulary acquisition during the past seventeen years. Several studies have touched on this area to examine the potential of multimedia in a CALL environment in aiding L2 vocabulary acquisition. In this review, the…

  2. Exploring Learner Factors in Second Language (L2) Incidental Vocabulary Acquisition through Reading (United States)

    Zhao, Aiping; Guo, Ying; Biales, Carrie; Olszewski, Arnold


    This study examined the predictive role of several learner factors in second language (L2) incidental vocabulary acquisition through reading: L2 proficiency, motivation, anxiety, and mastery of strategies. Participants were 129 English learners in a comprehensive university in China. Participants read two English texts and were given an…

  3. Dispersion and Frequency: Is There Any Difference as Regards Their Relation to L2 Vocabulary Gains? (United States)

    Alcaraz-Mármol, Gema


    Despite the current importance given to L2 vocabulary acquisition in the last two decades, considerable deficiencies are found in L2 students' vocabulary size. One of the aspects that may influence vocabulary learning is word frequency. However, scholars warn that frequency may lead to wrong conclusions if the way words are distributed is ignored.…

  4. The Effects of Hypertext Glosses on L2 Vocabulary Acquisition: A Meta-Analysis (United States)

    Yun, Jeehwan


    This study examines (1) the effects of hypertext gloss use on L2 vocabulary acquisition in computerized reading contexts; (2) which specific combination of either text-only (single) or text + visual (multiple) hypertext glosses is more effective on L2 vocabulary acquisition; and (3) potential moderators to systematically account for between study…

  5. Diction and Expression in Error Analysis Can Enhance Academic Writing of L2 University Students (United States)

    Sajid, Muhammad


    Without proper linguistic competence in English language, academic writing is one of the most challenging tasks, especially, in various genre specific disciplines by L2 novice writers. This paper examines the role of diction and expression through error analysis in English language of L2 novice writers' academic writing in interdisciplinary texts…

  6. The Status of the Auxiliary "Do" in L1 and L2 English Negative Clauses (United States)

    Perales, Susana


    This paper addresses the issue of whether negative sentences containing auxiliary "do" in L1 and L2 English share the same underlying syntactic representation. To this end, I compare the negative sentences produced by 77 bilingual (Spanish/Basque) L2 learners of English with the corresponding data available for L1 acquirers reported on in Schutze…

  7. Web-Based Collaborative Writing in L2 Contexts: Methodological Insights from Text Mining (United States)

    Yim, Soobin; Warschauer, Mark


    The increasingly widespread use of social software (e.g., Wikis, Google Docs) in second language (L2) settings has brought a renewed attention to collaborative writing. Although the current methodological approaches to examining collaborative writing are valuable to understand L2 students' interactional patterns or perceived experiences, they can…

  8. L2-Proficiency-Dependent Laterality Shift in Structural Connectivity of Brain Language Pathways

    NARCIS (Netherlands)

    Xiang, Huadong; van Leeuwen, Tessa Marije; Dediu, Dan; Roberts, Leah; Norris, David G.; Hagoort, Peter


    Diffusion tensor imaging (DTI) and a longitudinal language learning approach were applied to investigate the relationship between the achieved second language (L2) proficiency during L2 learning and the reorganization of structural connectivity between core language areas. Language proficiency tests

  9. The acquisition of grammatical gender in L2 German by learners ...

    African Journals Online (AJOL)

    grammatical gender in German by first language (L1) speakers of Afrikaans, English ... feminine – and the target L2 has three genders – masculine, feminine and neuter ..... L1 transfer revisited: the L2 acquisition of telicity marking in English by.

  10. L2 Reading Ability: Further Insight into the Short-Circuit Hypothesis. (United States)

    Taillefer, Gail F.


    Discusses the notion of a language proficiency threshold that short circuits the transfer of reading ability from the native language (L1) to a second language (L2). This study, in which cognitive complexity of tasks and students' L2 proficiency levels vary, focuses on university students in France reading preprofessional English texts. (39…

  11. Long-term convergence of speech rhythm in L1 and L2 English

    NARCIS (Netherlands)

    Quené, H; Orr, Rosemary


    When talkers from various language backgrounds use L2 English as a lingua franca, their accents of English are expected to converge, and talkers’ rhythmical patterns are predicted to converge too. Prosodic convergence was studied among talkers who lived in a community where L2 English is used

  12. College Students' Possible L2 Self Development in an EFL Context during the Transition Year (United States)

    Zhan, Ying; Wan, Zhi Hong


    In the field of second language learning motivation, the studies on process-oriented nature of possible L2 selves are scarce. In order to address this research gap, this study explored how a group of five Chinese non-English-major undergraduates developed their possible L2 selves during the transition year from high school to university. The…

  13. Teacher Perception of Cultural Difference in L2 Materials: Is Filtering Culture the Right Approach? (United States)

    Hermessi, Tarek


    With the emergence of the intercultural approach to L2 teaching, several studies investigated teachers' attitudes and beliefs concerning the cultural dimension of L2 teaching in different foreign language settings. This study explored teachers' perceptions of the relationship between teaching English and culture in Tunisia, an EFL setting where…

  14. Word Boundaries in L2 Speech: Evidence from Polish Learners of English (United States)

    Schwartz, Geoffrey


    Acoustic and perceptual studies investgate B2-level Polish learners' acquisition of second language (L2) English word-boundaries involving word-initial vowels. In production, participants were less likely to produce glottalization of phrase-medial initial vowels in L2 English than in first language (L1) Polish. Perception studies employing word…

  15. Applying Cognitive Linguistics to Instructed L2 Learning: The English Modals (United States)

    Tyler, Andrea; Mueller, Charles M.; Ho, Vu


    This paper reports the results of a quasi-experimental effects-of-instruction study examining the efficacy of applying a Cognitive Linguistic (CL) approach to L2 learning of the semantics of English modals. In spite of their frequency in typical input, modal verbs present L2 learners with difficulties, party due to their inherent…

  16. Bridging Theory and Practice: Developing Lower-Level Skills in L2 Reading (United States)

    Kato, Shigeo


    Studies on L2 reading have provided extensive evidence for the significant contribution of lower-level processing skills in learning to read and the critical impact on the overall development of L2 reading of more accurate and fluent connections between three sub-lexical components: phonology, orthography and semantics. The broad consensus among…

  17. Assessing Input Enhancement as Positive Factor and Its Impact on L2 Vocabulary Learning (United States)

    Motlagh, Seyyed Fariborz Pishdadi; Nasab, Mahdiyeh Seyed Beheshti


    Input enhancement's role to promote learners' awareness in L2 contexts has caused a tremendous amount of research. Conspicuously, by regarding all aspects of input enhancement, the study aimed to find out how differently many kinds of input enhancement factors such as bolding, underlining, and capitalizing impact on L2 learners' vocabulary…

  18. The Influence of Schema and Cultural Difference on L1 and L2 Reading (United States)

    Yang, Shi-sheng


    Reading in L1 shares numerous basic elements with reading in L2, and the processes also differ greatly. Intriguing questions involve whether there are two parallel cognitive processes at work, or whether there are processing strategies that accommodate both L1 and L2. This paper examines how reading in L1 is different from and similar to reading…

  19. L1 effects on the processing of grammatical gender in L2

    NARCIS (Netherlands)

    Sabourin, L; Foster-Cohen, S.; Nizegorodcew, A.


    This paper explores L1 effects on the L2 off-line processing of Dutch (grammatical gender) agreement The L2 participants had either German, English or a Romance language as their L1. Non-gender agreement (finiteness and agreement) was tested to ascertain the level of proficiency of the participants

  20. L2 Reading Comprehension and Its Correlates: A Meta-Analysis (United States)

    Jeon, Eun Hee; Yamashita, Junko


    The present meta-analysis examined the overall average correlation (weighted for sample size and corrected for measurement error) between passage-level second language (L2) reading comprehension and 10 key reading component variables investigated in the research domain. Four high-evidence correlates (with 18 or more accumulated effect sizes: L2

  1. L1 and L2 Distance Effects in Learning L3 Dutch (United States)

    Schepens, Job J.; der Slik, Frans; Hout, Roeland


    Many people speak more than two languages. How do languages acquired earlier affect the learnability of additional languages? We show that linguistic distances between speakers' first (L1) and second (L2) languages and their third (L3) language play a role. Larger distances from the L1 to the L3 and from the L2 to the L3 correlate with lower…

  2. Concurrent Data Elicitation Procedures, Processes, and the Early Stages of L2 Learning: A Critical Overview (United States)

    Leow, Ronald P.; Grey, Sarah; Marijuan, Silvia; Moorman, Colleen


    Given the current methodological interest in eliciting direct data on the cognitive processes L2 learners employ as they interact with L2 data during the early stages of the learning process, this article takes a critical and comparative look at three concurrent data elicitation procedures currently employed in the SLA literature: Think aloud (TA)…

  3. The production and processing of determiner-noun agreement in child L2 Dutch

    NARCIS (Netherlands)

    Blom, E.; Vasić, N.


    Recent research has shown that children who learn Dutch as their second language (L2) have difficulties with Dutch grammatical gender. This study shows that six to nine year old L2 Dutch children whose first language (L1) is Turkish noticed incorrect gender agreement between determiner and noun only

  4. Differences in process and process-product relations in L2 writing

    NARCIS (Netherlands)

    van Weijen, D.; van den Bergh, H.; Rijlaarsdam, G.; Sanders, T.


    This study examines whether writers vary how they write under influence of the changing task situation when writing in a second language (L2) and, if so, whether differences in the way they write are related to variations in text quality. Twenty first year students wrote four texts each in their L2

  5. The Use of Conjunctions in Cognitively Simple versus Complex Oral L2 Tasks (United States)

    Michel, Marije C.


    The present study explores the use of conjunctions in simple versus complex argumentative tasks performed by second language (L2) learners as a specific measure for the amount of reasoning involved in task performance. The Cognition Hypothesis (Robinson, 2005) states that an increase in cognitive task complexity promotes improvements in L2

  6. Importanza della diversità diatopica nell’insegnamento della lingua spagnola come L2

    Directory of Open Access Journals (Sweden)

    Silvia Lafuente


    Full Text Available The syncretic cultural identity, in which the Spanish language and its linguistic hegemony are grounded and have reflected its political hegemony, led Spain to take on a predominant role in standardization over the centuries. However, the present situation of the Spanish language is characterized by pluricentrism covering the vast territory in which the language is spoken. This means that a number of cen- ters have set up prestigious standard models providing norms for a country or region. Therefore, a fair enactment of this polycentrism requires national norms, different ways of codification of the Spanish language, answers to geographical and social forms which have split after a common departure and the idea that the varieties of the Spanish language fulfill speakers’ different expressive requirements and help to enhance national identities, in the face of the domination of the peninsular model. This point of view must guide linguistic research, methodology in lexicography, school grammar, translation of foreign languages and especially the teaching of Spanish as L2.

  7. L2 Writing in Test and Non-test Situations: Process and Product

    Directory of Open Access Journals (Sweden)

    Baraa Khuder


    Full Text Available Test writers sometimes complain they cannot perform to their true abilities because of time constraints. We therefore examined differences in terms of process and product between texts produced under test and non-test conditions. Ten L2 postgraduates wrote two argumentative essays, one under test conditions, with only forty minutes being allowed and without recourse to resources, and one under non-test conditions, with unlimited time as well as access to the Internet. Keystroke logging, screen capture software, and stimulated recall protocols were used, participants explaining and commenting on their writing processes. Sixteen writing process types were identified. Higher proportions of the processes of translation and surface revision were recorded in the test situation, while meaningful revision and evaluation were both higher in the non-test situation. There was a statistically significant difference between time allocation for different processes at different stages. Experienced teachers awarded the non-test texts a mean score of almost one point (0.8 higher. A correlational analysis examining the relationship between writing process and product quality showed that while the distribution of writing processes can have an impact on text quality in the test situation, it had no effect on the product in the non-test situation.

  8. Chemopreventive effect of chalcone derivative, L2H17, in colon cancer development

    International Nuclear Information System (INIS)

    Xu, Shanmei; Chen, Minxiao; Chen, Wenbo; Hui, Junguo; Ji, Jiansong; Hu, Shuping; Zhou, Jianmin; Wang, Yi; Liang, Guang


    Colon cancer is the third most commonly diagnosed cancer and the second leading cause of cancer mortality worldwide. Chalcone and its derivatives are reported to exhibit anti-cancer effects in several cancer cell lines, including colon cancer cells. In addition, chalcones have advantages such as poor interaction with DNA and low risk of mutagenesity. In our previous study, a group of chalcone derivatives were synthesized and exhibited strong anti-inflammatory activities. In this study, we evaluated the anti-cancer effects of the chalcone derivative, L2H17, in colon cancer cells. The cytotoxicities of L2H17 on various colon cancer cell lines were investigated by MTT and clonogenic assay. Cell cycle and apoptosis analysis were performed to evaluate the molecular mechanism of L2H17-mediated inhibition of tumor growth. Also, scratch wound and matrigel invasion experiments were performed to estimate the cell migration and invasion after L2H17 treatment. Finally, we observed the anti-colon cancer effects of L2H17 in vivo. Our data show that compound L2H17 exhibited selective cytotoxic effect on colon cancer cells, via inducing G0/G1 cell cycle arrest and apoptosis in CT26.WT cells. Furthermore, L2H17 treatment decreased cell migration and invasion of CT26.WT cells. In addition, L2H17 possessed marked anti-tumor activity in vivo. The molecular mechanism of L2H17-mediated inhibition of tumor promotion and progression were function through inactivated NF-κB and Akt signaling pathways. All these findings show that L2H17 might be a potential growth inhibitory chalcones derivative for colon cancer cells

  9. Finding the key to successful L2 learning in groups and individuals

    Directory of Open Access Journals (Sweden)

    Wander Lowie


    Full Text Available A large body studies into individual differences in second language learning has shown that success in second language learning is strongly affected by a set of relevant learner characteristics ranging from the age of onset to motivation, aptitude, and personality. Most studies have concentrated on a limited number of learner characteristics and have argued for the relative importance of some of these factors. Clearly, some learners are more successful than others, and it is tempting to try to find the factor or combination of factors that can crack the code to success. However, isolating one or several global individual characteristics can only give a partial explanation of success in second language learning. The limitation of this approach is that it only reflects on rather general personality characteristics of learners at one point in time, while both language development and the factors affecting it are instances of complex dynamic processes that develop over time. Factors that have been labelled as “individual differences” as well as the development of proficiency are characterized by nonlinear relationships in the time domain, due to which the rate of success cannot be simply deduced from a combination of factors. Moreover, in complex dynamic systems theory (CDST literature it has been argued that a generalization about the interaction of variables across individuals is not warranted when we acknowledge that language development is essentially an individual process (Molenaar, 2015. In this paper, the viability of these generalizations is investigated by exploring the L2 development over time for two identical twins in Taiwan who can be expected to be highly similar in all respects, from their environment to their level of English proficiency, to their exposure to English, and to their individual differences. In spite of the striking similarities between these learners, the development of their L2 English over time was very different

  10. Approximation of Quantities of Interest in Stochastic PDEs by the Random Discrete L^2 Projection on Polynomial Spaces

    KAUST Repository

    Migliorati, G.


    In this work we consider the random discrete L^2 projection on polynomial spaces (hereafter RDP) for the approximation of scalar quantities of interest (QOIs) related to the solution of a partial differential equation model with random input parameters. In the RDP technique the QOI is first computed for independent samples of the random input parameters, as in a standard Monte Carlo approach, and then the QOI is approximated by a multivariate polynomial function of the input parameters using a discrete least squares approach. We consider several examples including the Darcy equations with random permeability, the linear elasticity equations with random elastic coefficient, and the Navier--Stokes equations in random geometries and with random fluid viscosity. We show that the RDP technique is well suited to QOIs that depend smoothly on a moderate number of random parameters. Our numerical tests confirm the theoretical findings in [G. Migliorati, F. Nobile, E. von Schwerin, and R. Tempone, Analysis of the Discrete $L^2$ Projection on Polynomial Spaces with Random Evaluations, MOX report 46-2011, Politecnico di Milano, Milano, Italy, submitted], which have shown that, in the case of a single uniformly distributed random parameter, the RDP technique is stable and optimally convergent if the number of sampling points is proportional to the square of the dimension of the polynomial space. Here optimality means that the weighted $L^2$ norm of the RDP error is bounded from above by the best $L^\\\\infty$ error achievable in the given polynomial space, up to logarithmic factors. In the case of several random input parameters, the numerical evidence indicates that the condition on quadratic growth of the number of sampling points could be relaxed to a linear growth and still achieve stable and optimal convergence. This makes the RDP technique very promising for moderately high dimensional uncertainty quantification.

  11. Applying Dynamical Systems Theory to Optimize Libration Point Orbit Stationkeeping Maneuvers for WIND (United States)

    Brown, Jonathan M.; Petersen, Jeremy D.


    NASA's WIND mission has been operating in a large amplitude Lissajous orbit in the vicinity of the interior libration point of the Sun-Earth/Moon system since 2004. Regular stationkeeping maneuvers are required to maintain the orbit due to the instability around the collinear libration points. Historically these stationkeeping maneuvers have been performed by applying an incremental change in velocity, or (delta)v along the spacecraft-Sun vector as projected into the ecliptic plane. Previous studies have shown that the magnitude of libration point stationkeeping maneuvers can be minimized by applying the (delta)v in the direction of the local stable manifold found using dynamical systems theory. This paper presents the analysis of this new maneuver strategy which shows that the magnitude of stationkeeping maneuvers can be decreased by 5 to 25 percent, depending on the location in the orbit where the maneuver is performed. The implementation of the optimized maneuver method into operations is discussed and results are presented for the first two optimized stationkeeping maneuvers executed by WIND.

  12. Analysis of LOFT loss-of-coolant experiments L2-2, L2-3, and L3-0

    International Nuclear Information System (INIS)

    Leach, L.P.; Linebarger, J.H.


    A summary of results from Loss-of-Coolant Experiments (LOCE) L2-2, L2-3, and L3-0, conducted in the Loss-of-Fluid Test (LOFT) facility, and conclusions from posttest analyses of the experimental data are presented. LOCEs L2-2 and L2-3 were nuclear large break experiments and were dominated by a core-wide fuel rod cladding rewet, which limited the maximum fuel temperature. Analytical models only conservatively predicted the measured fuel rod temperatures and will require improvements to provide best estimate predictions in this area. Analysis of a large commercial pressurized water reactor (PWR) indicates that the cladding rewet observed in LOFT is also likely to occur in a large PWR, and that, therefore, safety analysis calculations of large loss-of-coolant accidents (LOCA) are more conservative than previously thought. LOCE L3-0 was an isothermal small break (top of pressurizer) experiment and illustrated that the pressurizer fills after the primary system fluid saturates someplace other than the pressurizer itself, that the indicated pressurizer level is higher than the actual level, and that additional model development and assessment work is necessary in order to predict small LOCAs as accurately as large LOCAs

  13. The Beneficial Role of L1 Spoken Language Skills on Initial L2 Sign Language Learning: Cognitive and Linguistic Predictors of M2L2 Acquisition (United States)

    Williams, Joshua T.; Darcy, Isabelle; Newman, Sharlene D.


    Understanding how language modality (i.e., signed vs. spoken) affects second language outcomes in hearing adults is important both theoretically and pedagogically, as it can determine the specificity of second language (L2) theory and inform how best to teach a language that uses a new modality. The present study investigated which…

  14. Embodiment and second-language: automatic activation of motor responses during processing spatially associated L2 words and emotion L2 words in a vertical Stroop paradigm. (United States)

    Dudschig, Carolin; de la Vega, Irmgard; Kaup, Barbara


    Converging evidence suggests that understanding our first-language (L1) results in reactivation of experiential sensorimotor traces in the brain. Surprisingly, little is known regarding the involvement of these processes during second-language (L2) processing. Participants saw L1 or L2 words referring to entities with a typical location (e.g., star, mole) (Experiment 1 & 2) or to an emotion (e.g., happy, sad) (Experiment 3). Participants responded to the words' ink color with an upward or downward arm movement. Despite word meaning being fully task-irrelevant, L2 automatically activated motor responses similar to L1 even when L2 was acquired rather late in life (age >11). Specifically, words such as star facilitated upward, and words such as root facilitated downward responses. Additionally, words referring to positive emotions facilitated upward, and words referring to negative emotions facilitated downward responses. In summary our study suggests that reactivation of experiential traces is not limited to L1 processing. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. How new L2 words (don't) become memories : Lexicalization in advanced L1 Dutch learners of L2 English as part of a longitudinal study

    NARCIS (Netherlands)

    Keijzer, Merel

    It is an undisputed fact that learning – and remembering – new words is key in successful second language acquisition. And yet researching how vocabulary acquisition takes place is one of the most difficult endeavors in second language acquisition. We can test how many L2 words a learner knows, but

  16. Working Memory Effects on L1 and L2 Processing of Ambiguous Relative Clauses by Korean L2 Learners of English (United States)

    Kim, Ji Hyon; Christianson, Kiel


    In this study, we report the results of two self-paced reading experiments that investigated working memory capacity effects on the processing of globally ambiguous relative clauses by advanced Korean second language (L2) learners of English. Consistent with previous monolingual literature on the processing of temporary ambiguity, we found that…

  17. Crystallization and preliminary X-ray crystallographic analysis of highly thermostable L2 lipase from the newly isolated Bacillus sp. L2

    International Nuclear Information System (INIS)

    Shariff, Fairolniza Mohd; Rahman, Raja Noor Zaliha Raja Abd.; Ali, Mohd Shukuri Mohamad; Chor, Adam Leow Thean; Basri, Mahiran; Salleh, Abu Bakar


    Thermostable recombinant L2 lipase from thermophilic Bacillus sp. L2 has been crystallized by using counter-diffusion method and diffracted to 2.7 Å resolution. The crystal belongs to the primitive orthorhombic space group P2 1 2 1 2 1 with unit-cell parameters a = 87.44, b = 94.90, c = 126.46 Å. Purified thermostable recombinant L2 lipase from Bacillus sp. L2 was crystallized by the counter-diffusion method using 20% PEG 6000, 50 mM MES pH 6.5 and 50 mM NaCl as precipitant. X-ray diffraction data were collected to 2.7 Å resolution using an in-house Bruker X8 PROTEUM single-crystal diffractometer system. The crystal belonged to the primitive orthorhombic space group P2 1 2 1 2 1 , with unit-cell parameters a = 87.44, b = 94.90, c = 126.46 Å. The asymmetric unit contained one single molecule of protein, with a Matthews coefficient (V M ) of 2.85 Å 3 Da −1 and a solvent content of 57%

  18. L2-stability of the Vlasov-Maxwell-Boltzmann system near global Maxwellians

    International Nuclear Information System (INIS)

    Ha, Seung-Yeal; Xiao, Qinghua; Xiong, Linjie; Zhao, Huijiang


    We present a L 2 -stability theory of the Vlasov-Maxwell-Boltzmann system for the two-species collisional plasma. We show that in a perturbative regime of a global Maxwellian, the L 2 -distance between two strong solutions can be controlled by that between initial data in a Lipschitz manner. Our stability result extends earlier results [Ha, S.-Y. and Xiao, Q.-H., “A revisiting to the L 2 -stability theory of the Boltzmann equation near global Maxwellians,” (submitted) and Ha, S.-Y., Yang, X.-F., and Yun, S.-B., “L 2 stability theory of the Boltzmann equation near a global Maxwellian,” Arch. Ration. Mech. Anal. 197, 657–688 (2010)] on the L 2 -stability of the Boltzmann equation to the Boltzmann equation coupled with self-consistent external forces. As a direct application of our stability result, we show that classical solutions in Duan et al. [“Optimal large-time behavior of the Vlasov-Maxwell-Boltzmann system in the whole space,” Commun. Pure Appl. Math. 24, 1497–1546 (2011)] and Guo [“The Vlasov-Maxwell-Boltzmann system near Maxwellians,” Invent. Math. 153(3), 593–630 (2003)] satisfy a uniform L 2 -stability estimate. This is the first result on the L 2 -stability of the Boltzmann equation coupled with self-consistent field equations in three dimensions

  19. Input frequencies in processing of verbal morphology in L1 and L2: Evidence from Russian

    Directory of Open Access Journals (Sweden)

    Tatiana Chernigovskaya


    Full Text Available In this study we take a usage-based perspective on the analysis of data from the acquisition of verbal morphology by Norwegian adult learners of L2 Russian, as compared to children acquiring Russian as an L1. According to the usage-based theories, language learning is input-driven and frequency of occurrence of grammatical structures and lexical items in the input plays a key role in this process. We have analysed to what extent the acquisition and processing of Russian verbal morphology by children and adult L2 learners is dependent on the input factors, in particular on type and token frequencies. Our analysis of the L2 input based on the written material used in the instruction shows a different distribution of frequencies as compared to the target language at large. The results of the tests that elicited present tense forms of verbs belonging to four different inflectional classes (-AJ-, -A-, -I-, and -OVA- have demonstrated that for both Russian children and L2 learners type frequency appears to be an important factor, influencing both correct stem recognition and generalisations. The results have also demonstrated token frequency effects. For L2 learners we observed also effects of formal instruction and greater reliance on morphological cues. In spite of the fact that L2 learners did not match completely any of the child groups, there are many similarities between L1 and L2 morphological processing, the main one being the role of frequency.

  20. Antibody Competition Reveals Surface Location of HPV L2 Minor Capsid Protein Residues 17–36

    Directory of Open Access Journals (Sweden)

    Stephanie M. Bywaters


    Full Text Available The currently available nonavalent human papillomavirus (HPV vaccine exploits the highly antigenic L1 major capsid protein to promote high-titer neutralizing antibodies, but is limited to the HPV types included in the vaccine since the responses are highly type-specific. The limited cross-protection offered by the L1 virus-like particle (VLP vaccine warrants further investigation into cross-protective L2 epitopes. The L2 proteins are yet to be fully characterized as to their precise placement in the virion. Adding to the difficulties in localizing L2, studies have suggested that L2 epitopes are not well exposed on the surface of the mature capsid prior to cellular engagement. Using a series of competition assays between previously mapped anti-L1 monoclonal antibodies (mAbs (H16.V5, H16.U4 and H16.7E and novel anti-L2 mAbs, we probed the capsid surface for the location of an L2 epitope (aa17–36. The previously characterized L1 epitopes together with our competition data is consistent with a proposed L2 epitope within the canyons of pentavalent capsomers.

  1. Antibody Competition Reveals Surface Location of HPV L2 Minor Capsid Protein Residues 17-36. (United States)

    Bywaters, Stephanie M; Brendle, Sarah A; Tossi, Kerstin P; Biryukov, Jennifer; Meyers, Craig; Christensen, Neil D


    The currently available nonavalent human papillomavirus (HPV) vaccine exploits the highly antigenic L1 major capsid protein to promote high-titer neutralizing antibodies, but is limited to the HPV types included in the vaccine since the responses are highly type-specific. The limited cross-protection offered by the L1 virus-like particle (VLP) vaccine warrants further investigation into cross-protective L2 epitopes. The L2 proteins are yet to be fully characterized as to their precise placement in the virion. Adding to the difficulties in localizing L2, studies have suggested that L2 epitopes are not well exposed on the surface of the mature capsid prior to cellular engagement. Using a series of competition assays between previously mapped anti-L1 monoclonal antibodies (mAbs) (H16.V5, H16.U4 and H16.7E) and novel anti-L2 mAbs, we probed the capsid surface for the location of an L2 epitope (aa17-36). The previously characterized L1 epitopes together with our competition data is consistent with a proposed L2 epitope within the canyons of pentavalent capsomers.

  2. Asimmetrie L1/L2: una sfida nella didattica di “lingua e traduzione”.

    Directory of Open Access Journals (Sweden)

    Laura Salmon


    Full Text Available Asymmetries Between L1 and L2: a Challenge in the Teaching of "Language and Translation" Language teaching is deeply connected to the cognitive and brain sciences. The attribution of meaning of linguistic messages depends on the interaction between the communicant’s brain and the external world. The interaction is based on the cognitive and emotional experience shared by a L-community. Competence in L2 is acquired by the development of an internal data base of contextualised .units of living speech. (Lurija 1976. L2 teaching is particularly successful when the L2 units are inscribed in memory by means of the functionally equivalent L1 units. Selection of the L1/L2 correspondent units is due to the principle of markedness: each unit of L1 has a functional equivalent in one and only one unit of the L2. Because of the interlingual asymmetries (a set of Italian/Russian examples is given, functional equivalence differs from morphosyntactic and lexical equivalence. The competency in ascribing a degree of markedness to each linguistic unit needs the regular implicit acquisition of the L2 intonational and prosodic system; the processes of the metalinguistic conscious reflection are instead a .hindrance. to the procedural acting of a “living speaker”.

  3. Modulation ofTcf7l2 expression alters behavior in mice.

    Directory of Open Access Journals (Sweden)

    Daniel Savic

    Full Text Available The comorbidity of type 2 diabetes (T2D with several psychiatric diseases is well established. While environmental factors may partially account for these co-occurrences, common genetic susceptibilities could also be implicated in the confluence of these diseases. In support of shared genetic burdens, TCF7L2, the strongest genetic determinant for T2D risk in the human population, has been recently implicated in schizophrenia (SCZ risk, suggesting that this may be one of many loci that pleiotropically influence both diseases. To investigate whether Tcf7l2 is involved in behavioral phenotypes in addition to its roles in glucose metabolism, we conducted several behavioral tests in mice with null alleles of Tcf7l2 or overexpressing Tcf7l2. We identified a role for Tcf7l2 in anxiety-like behavior and a dose-dependent effect of Tcf7l2 alleles on fear learning. None of the mutant mice showed differences in prepulse inhibition (PPI, which is a well-established endophenotype for SCZ. These results show that Tcf7l2 alters behavior in mice. Importantly, these differences are observed prior to the onset of detectable glucose metabolism abnormalities. Whether these differences are related to human anxiety-disorders or schizophrenia remains to be determined. These animal models have the potential to elucidate the molecular basis of psychiatric comorbidities in diabetes and should therefore be studied further.

  4. Fixed Points

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 5; Issue 5. Fixed Points - From Russia with Love - A Primer of Fixed Point Theory. A K Vijaykumar. Book Review Volume 5 Issue 5 May 2000 pp 101-102. Fulltext. Click here to view fulltext PDF. Permanent link:

  5. Tipping Point

    Medline Plus

    Full Text Available ... OnSafety CPSC Stands for Safety The Tipping Point Home > 60 Seconds of Safety (Videos) > The Tipping Point ... 24 hours a day. For young children whose home is a playground, it’s the best way to ...

  6. Tipping Point

    Medline Plus

    Full Text Available ... 60 Seconds of Safety (Videos) > The Tipping Point The Tipping Point by CPSC Blogger September 22, 2009 appliance child Childproofing CPSC danger death electrical fall furniture head injury product safety television tipover tv Watch the video in Adobe Flash ...

  7. How does language distance between L1 and L2 affect the L2 brain network? An fMRI study of Korean-Chinese-English trilinguals. (United States)

    Kim, Say Young; Qi, Ting; Feng, Xiaoxia; Ding, Guosheng; Liu, Li; Cao, Fan


    The present study tested the hypothesis that language distance between first language (L1) and second language (L2) influences the assimilation and accommodation pattern in Korean-Chinese-English trilinguals. The distance between English and Korean is smaller than that between Chinese and Korean in terms of orthographic transparency, because both English and Korean are alphabetic, whereas Chinese is logographic. During fMRI, Korean trilingual participants performed a visual rhyming judgment task in three languages (Korean: KK, Chinese: KC, English: KE). Two L1 control groups were native Chinese and English speakers performing the task in their native languages (CC and EE, respectively). The general pattern of brain activation of KC was more similar to that of CC than KK, suggesting accommodation. Higher accuracy in KC was associated with decreased activation in regions of the KK network, suggesting reduced assimilation. In contrast, the brain activation of KE was more similar to that of KK than EE, suggesting assimilation. Higher accuracy in KE was associated with decreased activation in regions of the EE network, suggesting reduced accommodation. Finally, an ROI analysis on the left middle frontal gyrus revealed greater activation for KC than for KE, suggesting its selective involvement in the L2 with more arbitrary mapping between orthography and phonology (i.e., Chinese). Taken together, the brain network involved in L2 reading is similar to the L1 network when L2 and L1 are similar in orthographic transparency, while significant accommodation is expected when L2 is more opaque than L1. Copyright © 2015. Published by Elsevier Inc.

  8. EX1004L2 Water Column Summary Report and Profile Data Collection (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A complete set of water column profile data and CTD Summary Report (if generated) generated by the Okeanos Explorer during EX1004L2: Exploration Indonesia - Bitung...

  9. EX1605L2 Water Column Summary Report and Profile Data Collection (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A complete set of water column profile data and CTD Summary Report (if generated) generated by the Okeanos Explorer during EX1605L2: CAPSTONE CNMI and Mariana Trench...

  10. EX1504L2 Dive04 Ancillary Data Collection including reports, kmls, spreadsheets, images and data (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  11. EX1504L2 Dive02 Ancillary Data Collection including reports, kmls, spreadsheets, images and data (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  12. EX1304L2 Water Column Summary Report and Profile Data Collection (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A complete set of water column profile data and CTD Summary Report (if generated) generated by the Okeanos Explorer during EX1304L2: Northeast U.S. Canyons...

  13. EX1504L2 Dive17 Ancillary Data Collection including reports, kmls, spreadsheets, images and data (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  14. EX1504L2 Dive11 Ancillary Data Collection including reports, kmls, spreadsheets, images and data (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  15. EX1504L2 Dive07 Ancillary Data Collection including reports, kmls, spreadsheets, images and data (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  16. EX1502L2 Water Column Summary Report and Profile Data Collection (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A complete set of water column profile data and CTD Summary Report (if generated) generated by the Okeanos Explorer during EX1502L2: Caribbean Exploration (Mapping)...

  17. EX1504L2 Dive13 Ancillary Data Collection including reports, kmls, spreadsheets, images and data (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  18. EX1504L2 Dive12 Ancillary Data Collection including reports, kmls, spreadsheets, images and data (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  19. EX1504L2 Dive09 Ancillary Data Collection including reports, kmls, spreadsheets, images and data (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  20. EX1504L2 Dive14 Ancillary Data Collection including reports, kmls, spreadsheets, images and data (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  1. EX1504L2 Dive18 Ancillary Data Collection including reports, kmls, spreadsheets, images and data (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  2. EX1504L2 Dive08 Ancillary Data Collection including reports, kmls, spreadsheets, images and data (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  3. EX1504L2 Dive03 Ancillary Data Collection including reports, kmls, spreadsheets, images and data (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  4. EX1504L2 Dive05 Ancillary Data Collection including reports, kmls, spreadsheets, images and data (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  5. EX1504L2 Dive15 Ancillary Data Collection including reports, kmls, spreadsheets, images and data (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  6. Emergence of the lymphogranuloma venereum L2c genovariant, Hungary, 2012 to 2016. (United States)

    Petrovay, Fruzsina; Balla, Eszter; Erdősi, Tímea


    In eastern Europe, few countries have so far reported laboratory-confirmed cases of lymphogranuloma venereum (LGV). Here we describe 22 LGV cases in men who have sex with men (MSM) detected in Hungary from November 2012 to July 2016. Sequence analyses show that 16 of these 22 cases were affected by the L2c genovariant, with from 2012 to 2014, one LGV L2c case detected per year, followed by seven cases in 2015 and six up to July 2016. Of the 16 total L2c LGV cases, 10 had severe haemorrhagic proctitis. These findings are concerning as cases with this new genovariant among MSM have not been frequently reported in Europe to date. More research is needed to assess the spread of the L2c genovariant and its potential association with virulence and severe clinical manifestation. This article is copyright of The Authors, 2017.

  7. EX1504L2 Dive06 Ancillary Data Collection including reports, kmls, spreadsheets, images and data (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  8. IceBridge Riegl Laser Altimeter L2 Geolocated Surface Elevation Triplets (United States)

    National Aeronautics and Space Administration — The IceBridge Riegl Laser Altimeter L2 Geolocated Surface Elevation Triplets (ILUTP2) data set contains surface range values for Antarctica and Greenland derived...

  9. EX1504L2 Dive10 Ancillary Data Collection including reports, kmls, spreadsheets, images and data (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Standard suite of ancillary data files generated through a scripting process following an ROV dive on NOAA Ship Okeanos Explorer during EX1504L2: Campaign to Address...

  10. EX1402L2 Water Column Summary Report and Profile Data Collection (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A complete set of water column profile data and CTD Summary Report (if generated) generated by the Okeanos Explorer during EX1402L2: Gulf of Mexico Mapping and...

  11. EX0909L2 Water Column Summary Report and Profile Data Collection (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A complete set of water column profile data and CTD Summary Report (if generated) generated by the Okeanos Explorer during EX0909L2: Mapping Field Trials - Necker...

  12. Dew Point


    Goldsmith, Shelly


    Dew Point was a solo exhibition originating at PriceWaterhouseCoopers Headquarters Gallery, London, UK and toured to the Centre de Documentacio i Museu Textil, Terrassa, Spain and Gallery Aoyama, Tokyo, Japan.

  13. Tipping Point

    Medline Plus

    Full Text Available ... Point by CPSC Blogger September 22, 2009 appliance child Childproofing CPSC danger death electrical fall furniture head injury product safety television tipover tv Watch the video in Adobe Flash ...

  14. Tipping Point (United States)

    ... Point by CPSC Blogger September 22, 2009 appliance child Childproofing CPSC danger death electrical fall furniture head injury product safety television tipover tv Watch the video in Adobe Flash ...

  15. Tipping Point

    Medline Plus

    Full Text Available ... Point by CPSC Blogger September 22, 2009 appliance child Childproofing CPSC danger death electrical fall furniture head ... see news reports about horrible accidents involving young children and furniture, appliance and tv tip-overs. The ...

  16. Tipping Point

    Medline Plus

    Full Text Available ... Point by CPSC Blogger September 22, 2009 appliance child Childproofing CPSC danger death electrical fall furniture head ... TV falls with about the same force as child falling from the third story of a building. ...

  17. Tipping Point

    Medline Plus

    Full Text Available ... Tipping Point by CPSC Blogger September 22, 2009 appliance child Childproofing CPSC danger death electrical fall furniture ... about horrible accidents involving young children and furniture, appliance and tv tip-overs. The force of a ...

  18. Main Ingredients for Success in L2 Academic Writing: Outlining, Drafting and Proofreading


    Munoz-Luna, Rosa


    Spanish undergraduates of English Studies are required to submit their essays in academic English, a genre which most of them are not acquainted with. This paper aims to explore the extralinguistic side of second language (L2) academic writing, more specifically, the combination of metalinguistic items (e.g. transition and frame markers, among others) with students' writing strategies when composing an academic text in L2 English. The research sample conveys a group of 200 Spanish undergradua...

  19. Mechanism of water oxidation by [Ru(bda)(L)2]: the return of the "blue dimer". (United States)

    Concepcion, Javier J; Zhong, Diane K; Szalda, David J; Muckerman, James T; Fujita, Etsuko


    We describe here a combined solution-surface-DFT calculations study for complexes of the type [Ru(bda)(L)2] including X-ray structure of intermediates and their reactivity, as well as pH-dependent electrochemistry and spectroelectrochemistry. These studies shed light on the mechanism of water oxidation by [Ru(bda)(L)2], revealing key features unavailable from solution studies with sacrificial oxidants.

  20. TCF7L2 expression in diabetic patients undergoing bariatric surgery. (United States)

    Hindle, A Katharine; Brody, Fred; Tevar, Rahul; Kluk, Brian; Hill, Sarah; McCaffrey, Timothy; Fu, Sidney


    The cause of diabetes in morbidly obese patients is multifactorial, including genetic, social, and dietary components. Transcription factor 7-like 2 (TCF7L2) is a gene that is related to the development of diabetes. This pilot study examines TCF7L2 expression in liver samples obtained from morbidly obese patients undergoing bariatric surgery. TCF7L2 expression is compared between diabetic and nondiabetic patients. Liver samples were obtained from 20 morbidly obese patients undergoing bariatric surgery. Samples were flash frozen in liquid nitrogen. Total RNA was extracted from tissue samples using the TRIzol reagent (Invitrogen Inc, Carlsbad, CA). Using the iScript cDNA synthesis kit (Bio-Rad Laboratories, Hercules,CA), cDNA was synthesized. Quantitative polymerase chain reaction (qPCR) was done using SYBR Green qPCR Reagents (Stratagene, Cedar Creek TX) and the 7300 Real-Time PCR system (Applied Biosystems, Foster City CA). Preoperative demographic and gene expression data were correlated using univariate analysis and logistic regression models. Only associations with a p-value less than 0.05 were considered significant. For the entire group, there was no correlation between body mass index (BMI) and TCF7L2 expression. In morbidly obese nondiabetic patients, there was a positive correlation between TCF7L2 expression and BMI (R(2)=0.21). In morbidly obese diabetic patients, there was an inverse correlation between TCF7L2 expression and BMI (R(2)=0.58). There was no significant relationship between TCF7L2 expression and age or glycosylated hemoglobin (HbA1c). The cause of diabetes is multifactorial but the data from our pilot study documents the relationship of TCF7L2 with type 2 diabetes in morbidly obese patients.

  1. Lymphogranuloma Venereum-Serovar L2b Presenting With Painful Genital Ulceration: An Emerging Clinical Presentation? (United States)

    Haber, Roger; Maatouk, Ismaël; de Barbeyrac, Bertille; Bagot, Martine; Janier, Michel; Fouéré, Sébastien


    These 5 cases of atypical inflammatory lymphogranula venereum (LGV) serovar L2b presenting initially with edema and persistent painful ulceration illustrate that clinical manifestations of LGV in the current outbreak in men who have sex with men reflect the influence of both the serovars virulence and the host immune system and are not confined to proctitis. L2b serovar could have a particular high virulence profile, and the need for awareness of LGV as a cause of genital ulceration is crucial.

  2. L1 and L2 Spoken Word Processing: Evidence from Divided Attention Paradigm. (United States)

    Shafiee Nahrkhalaji, Saeedeh; Lotfi, Ahmad Reza; Koosha, Mansour


    The present study aims to reveal some facts concerning first language (L 1 ) and second language (L 2 ) spoken-word processing in unbalanced proficient bilinguals using behavioral measures. The intention here is to examine the effects of auditory repetition word priming and semantic priming in first and second languages of these bilinguals. The other goal is to explore the effects of attention manipulation on implicit retrieval of perceptual and conceptual properties of spoken L 1 and L 2 words. In so doing, the participants performed auditory word priming and semantic priming as memory tests in their L 1 and L 2 . In a half of the trials of each experiment, they carried out the memory test while simultaneously performing a secondary task in visual modality. The results revealed that effects of auditory word priming and semantic priming were present when participants processed L 1 and L 2 words in full attention condition. Attention manipulation could reduce priming magnitude in both experiments in L 2 . Moreover, L 2 word retrieval increases the reaction times and reduces accuracy on the simultaneous secondary task to protect its own accuracy and speed.

  3. Multi-view L2-SVM and its multi-view core vector machine. (United States)

    Huang, Chengquan; Chung, Fu-lai; Wang, Shitong


    In this paper, a novel L2-SVM based classifier Multi-view L2-SVM is proposed to address multi-view classification tasks. The proposed Multi-view L2-SVM classifier does not have any bias in its objective function and hence has the flexibility like μ-SVC in the sense that the number of the yielded support vectors can be controlled by a pre-specified parameter. The proposed Multi-view L2-SVM classifier can make full use of the coherence and the difference of different views through imposing the consensus among multiple views to improve the overall classification performance. Besides, based on the generalized core vector machine GCVM, the proposed Multi-view L2-SVM classifier is extended into its GCVM version MvCVM which can realize its fast training on large scale multi-view datasets, with its asymptotic linear time complexity with the sample size and its space complexity independent of the sample size. Our experimental results demonstrated the effectiveness of the proposed Multi-view L2-SVM classifier for small scale multi-view datasets and the proposed MvCVM classifier for large scale multi-view datasets. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Effectiveness of L2 spinal nerve infiltration for selective discogenic low back pain patients

    International Nuclear Information System (INIS)

    Ohtori, Seiji; Nakamura, Shinichiro; Koshi, Takana


    It has been reported that rat L5/6 lumbar discs are innervated mainly by L2 dorsal root ganglion neurons. We previously reported that L2 spinal nerve infiltration was effective for discogenic low back pain (DLBP) patients, although the diagnosis was based only on the results of physical examination, plain films, and magnetic resonance imaging (MRI). The purpose of the current study was to evaluate L2 spinal nerve block for DLBP patients retrospectively based on MRI findings and surgical results. A total of 62 patients with only LBP and no accompanying radicular pain were investigated. Patients had only one level of disc degeneration on MRI. When pain was provoked during discography, we performed surgery at the next stage (40 patients). In all, 22 patients were excluded owing to negative discography results. Of the 40 patients, we evaluated 25 strictly selected patients suffering from DLBP. DLBP was diagnosed when the patient experienced pain relief at least 2 years after anterior lumbar interbody fusion. Fifteen patients who did not show pain relief after surgery were used for the non-DLBP group. L2 spinal nerve infiltration using 1.5 ml of lidocaine was performed in all 40 patients before surgery. The visual analogue scale (VAS) score after L2 spinal nerve infiltration was recorded, and an association of L2 spinal nerve infiltration and DLBP was explored. Low back pain scores assessed using the VAS score, the Japanese Orthopedic Association score, and the Oswestry Disability Index score in the two groups were not significantly different. L2 spinal nerve infiltration was effective for 27 patients but not effective for 13 patients; the VAS score after 15 min and 2 h improved in the DLBP group compared with that of the non-DLBP group (P<0.05). L2 spinal nerve infiltration was more effective in DLBP patients (21 patients, 84%) than in the non-DLBP group (6 patients, 40%) (P<0.05). In the current study, L2 spinal nerve infiltration was effective in 84% of selected DLBP

  5. Minor Capsid Protein L2 Polytope Induces Broad Protection against Oncogenic and Mucosal Human Papillomaviruses. (United States)

    Pouyanfard, Somayeh; Spagnoli, Gloria; Bulli, Lorenzo; Balz, Kathrin; Yang, Fan; Odenwald, Caroline; Seitz, Hanna; Mariz, Filipe C; Bolchi, Angelo; Ottonello, Simone; Müller, Martin


    The amino terminus of the human papillomavirus (HPV) minor capsid protein L2 contains a major cross-neutralization epitope which provides the basis for the development of a broadly protecting HPV vaccine. A wide range of protection against different HPV types would eliminate one of the major drawbacks of the commercial, L1-based prophylactic vaccines. Previously, we have reported that insertion of the L2 epitope into a scaffold composed of bacterial thioredoxin protein generates a potent antigen inducing comprehensive protection against different animal and human papillomaviruses. We also reported, however, that although protection is broad, some oncogenic HPV types escape the neutralizing antibody response, if L2 epitopes from single HPV types are used as immunogen. We were able to compensate for this by applying a mix of thioredoxin proteins carrying L2 epitopes from HPV16, -31, and -51. As the development of a cost-efficient HPV prophylactic vaccines is one of our objectives, this approach is not feasible as it requires the development of multiple good manufacturing production processes in combination with a complex vaccine formulation. Here, we report the development of a thermostable thioredoxin-based single-peptide vaccine carrying an L2 polytope of up to 11 different HPV types. The L2 polytope antigens have excellent abilities in respect to broadness of protection and robustness of induced immune responses. To further increase immunogenicity, we fused the thioredoxin L2 polytope antigen with a heptamerization domain. In the final vaccine design, we achieve protective responses against all 14 oncogenic HPV types that we have analyzed plus the low-risk HPVs 6 and 11 and a number of cutaneous HPVs. IMPORTANCE Infections by a large number of human papillomaviruses lead to malignant and nonmalignant disease. Current commercial vaccines based on virus-like particles (VLPs) effectively protect against some HPV types but fail to do so for most others. Further, only

  6. Rapid L2 Word Learning through High Constraint Sentence Context: An Event-Related Potential Study

    Directory of Open Access Journals (Sweden)

    Baoguo Chen


    Full Text Available Previous studies have found quantity of exposure, i.e., frequency of exposure (Horst et al., 1998; Webb, 2008; Pellicer-Sánchez and Schmitt, 2010, is important for second language (L2 contextual word learning. Besides this factor, context constraint and L2 proficiency level have also been found to affect contextual word learning (Pulido, 2003; Tekmen and Daloglu, 2006; Elgort et al., 2015; Ma et al., 2015. In the present study, we adopted the event-related potential (ERP technique and chose high constraint sentences as reading materials to further explore the effects of quantity of exposure and proficiency on L2 contextual word learning. Participants were Chinese learners of English with different English proficiency levels. For each novel word, there were four high constraint sentences with the critical word at the end of the sentence. Learners read sentences and made semantic relatedness judgment afterwards, with ERPs recorded. Results showed that in the high constraint condition where each pseudoword was embedded in four sentences with consistent meaning, N400 amplitude upon this pseudoword decreased significantly as learners read the first two sentences. High proficiency learners responded faster in the semantic relatedness judgment task. These results suggest that in high quality sentence contexts, L2 learners could rapidly acquire word meaning without multiple exposures, and L2 proficiency facilitated this learning process.

  7. TCF7L2 polymorphisms and inflammatory markers before and after treatment with fenofibrate

    Directory of Open Access Journals (Sweden)

    Kabagambe Edmond K


    Full Text Available Abstract Background Inflammation is implicated in causing diabetes. We tested whether transcription factor 7 like-2 (TCF7L2 gene polymorphisms (rs12255372 and rs7903146, consistently associated with type 2 diabetes, are associated with plasma concentrations of inflammatory markers before and after three weeks of daily treatment with fenofibrate. Methods Men and women in the Genetics of Lipid-Lowering Drugs and Diet Network study (n = 1025, age 49 ± 16 y were included. All participants suspended use of lipid-lowering drugs for three weeks and were then given 160 mg/day of fenofibrate for three weeks. Inflammatory markers and lipids were measured before and after fenofibrate. ANOVA was used to test for differences across TCF7L2 genotypes. Results Under the additive or dominant model, there were no significant differences (P > 0.05 in the concentrations of inflammatory markers (hsCRP, IL-2, IL-6, TNF-α and MCP-1 across TCF7L2 genotypes in the period before or after treatment. For both rs12255372 and rs7903146, homozygote T-allele carriers had significantly higher (P Conclusion Overall these data show no association between TCF7L2 polymorphisms and the inflammatory markers suggesting that the effects of TCF7L2 on diabetes may not be via inflammation.

  8. L1/L2 Differences in the Acquisition of Form-Meaning Pairings in a Second Language (United States)

    McManus, Kevin


    This paper examines the impact of L1/L2 form-meaning differences in the domain of aspect to investigate whether L2 learners are able to acquire properties of the L2 that are different from the L1. Oral data were collected from English- and German-speaking university learners of French L2 (n = 75) at two different levels of proficiency. The results…

  9. The role of oral corrective feedback in L2 Portuguese classrooms

    Directory of Open Access Journals (Sweden)

    Bárbara Battistelli Rauber


    Full Text Available Languages are generally acquired along with and for others, in varied environments which influence second language (L2 learning. One of the most important influences of the linguistic environment is that it provides learners with information about the incorrectness of their utterances (ORTEGA, 2009. This process is referred as Corrective Feedback (LYSTER; RANTA, 1997, RUSSEL; SPADA, 2006, which is a complex phenomenon that has different functions in formal L2 instruction. The purpose of the current study was to investigate the types of oral CF in L2 Portuguese classrooms and to analyze how learners responded to CF provided by their teachers. The data presented were obtained from the observation of lessons in an elementary and an intermediate group of a Portuguese course offered at a private American university. The results of this observational study show that elicitation, explicit correction and metalinguistic feedback are the main CF methods employed by the teachers.

  10. Control and Stabilization of the Benjamin-Ono Equation in {L^2({{T})}} (United States)

    Laurent, Camille; Linares, Felipe; Rosier, Lionel


    We study the control and stabilization of the Benjamin-Ono equation in {L^2({T})}, the lowest regularity where the initial value problem is well-posed. This problem was already initiated in Linares and Rosier (Trans Am Math Soc 367:4595-4626, 2015) where a stronger stabilization term was used (that makes the equation of parabolic type in the control zone). Here we employ a more natural stabilization term related to the L 2-norm. Moreover, by proving a theorem of controllability in L 2, we manage to prove the global controllability in large time. Our analysis relies strongly on the bilinear estimates proved in Molinet and Pilod (Anal PDE 5:365-395, 2012) and some new extension of these estimates established here.

  11. The expression of Path in L2 Danish by German and Turkish learners

    DEFF Research Database (Denmark)

    Jessen, Moiken


    Do language learners think in their first language (L1) when using their second language (L2)? This study explores the nature of crosslinguistic influence by investigating how German and Turkish learners of Danish express motion, paying special attention to the semantics of Path. We examined three...... aspects: overall Path frequency, Path complexity, and the subcomponents of Path. The presence of L1 influence in each aspect reflects how the interplay between form and meaning is carried over as a whole to the L2. In particular, we show how the selection of a specific Path meaning for expression in the L......2 has its root in the structural and semantic properties of the L1. This raises important questions regarding how form and meaning are organized in the learner's mind....

  12. Limitations of the influence of English phonetics and phonology on L2 Spanish rhotics

    Directory of Open Access Journals (Sweden)

    Michael Kevin Olsen


    Full Text Available This study investigates L2 Spanish rhotic production in intermediate learners of Spanish, specifically addressing the duration of the influence of L1 English rhotic articulations and a phonetic environment involving English taps on the acquisition of Spanish taps and trills that Olsen (2012 found. Results from multiple linear regressions involving thirty-five students in Spanish foreign language classes show that the effect of English rhotic articulations evident in beginners has disappeared after four semesters of Spanish study. However, results from paired samples t-tests show that these more advanced learners produced accurate taps significantly more in words containing phonetic environments that produce taps in English. This effect is taken as evidence that L1 phonetic influences have a shorter duration on L2 production than do L1 phonological influences. These results provide insights into L2 rhotic acquisition which Spanish educators and students can use to formulate reasonable pronunciation expectations.

  13. The Dirichlet problem with L2-boundary data for elliptic linear equations

    CERN Document Server

    Chabrowski, Jan


    The Dirichlet problem has a very long history in mathematics and its importance in partial differential equations, harmonic analysis, potential theory and the applied sciences is well-known. In the last decade the Dirichlet problem with L2-boundary data has attracted the attention of several mathematicians. The significant features of this recent research are the use of weighted Sobolev spaces, existence results for elliptic equations under very weak regularity assumptions on coefficients, energy estimates involving L2-norm of a boundary data and the construction of a space larger than the usual Sobolev space W1,2 such that every L2-function on the boundary of a given set is the trace of a suitable element of this space. The book gives a concise account of main aspects of these recent developments and is intended for researchers and graduate students. Some basic knowledge of Sobolev spaces and measure theory is required.

  14. The Effects of Planned Instruction on Iranian L2 Learners' Interlanguage Pragmatic Development

    Directory of Open Access Journals (Sweden)

    Maryam Esmaeili


    Full Text Available The most compelling evidence that instruction in L2pragmatics is necessary comes from learners whoselanguage proficiency is advanced but their communicative actsfrequently contain pragmatic errors. The current studyevaluated the impact of explicit instruction on EFL learner'sawareness and production of three speech acts of request,apology, and complaint. It also probed whether learners’language proficiency plays any role in incorporatingpragmatic instruction into the L2 classroom. The instructionlasted for about 12 weeks. Achievement in L2 pragmaticswas assessed based on a pretest-posttest plan usingMultiple-Choice Discourse Comprehension Test (MDCTand Written Discourse Completion Test (WDCT. Thesignificant gains made by the experimental groups receivinginstruction support the claim recently made by instructionalpragmatics that explicit instruction does facilitate thedevelopment of pragmatically appropriate use of language.Yet, learners’ level of language proficiency had no significantrole in the incorporation of the instruction. Furthertheoretical issues are also discussed.

  15. Study of Heterogeneous Structure in Diesel Fuel Spray by Using Micro-Probe L2F (United States)

    Sakaguchi, Daisaku; Yamamoto, Shohei; Ueki, Hironobu; Ishdia, Masahiro

    A L2F (Laser 2-Focus velocimeter) was applied for the measurements of the velocity and size of droplets in diesel fuel sprays. The micro-scale probe of the L2F has an advantage in avoiding the multiple scattering from droplets in a dense region of fuel sprays. A data sampling rate of 15MHz has been achieved in the L2F system for detecting almost all of the droplets which passed through the measurement probe. Diesel fuel was injected into the atmosphere by using a common rail injector. Measurement positions were located along the spray axis at 10, 15, 20, 25, and 30 mm from the nozzle exit. Measurement result showed that the velocity and size of droplets decreased and the number density of droplets increased along the spray axis. It was clearly shown that the mass flow rate in the spray was highest near the spray tip and was lower inside the spray.

  16. Lexical Access in L2 Speech Production: a controlled serial search task

    Directory of Open Access Journals (Sweden)

    Gicele Vergine Vieira


    Full Text Available When it comes to lexical access in L2 speech production, working memory (WM seems to play a central role as for less automatized procedures require more WM capacity to be executed (Prebianca, 2007. With that in mind, this paper aims at claiming that bilingual lexical access qualifies as a controlled serial strategic search task susceptible to individual differences in WM capacity. Evidence in support of such claim is provided by the results of AUTHOR's (2010 study conducted so as to investigate the relationship between L2 lexical access, WMC and L2 proficiency. AUTHOR's (2010 findings indicate that bilingual lexical access entails underlying processes such as cue generation, set delimitation, serial search and monitoring, which to be carried out, require the allocation of attention. Attention is limited and, as a result, only higher spans were able to perform these underlying processes automatically.

  17. The L2 Passionate Interactional Imperative (for short “The L2 Pie”: It’s Hot or It’s Not!

    Directory of Open Access Journals (Sweden)

    Tim Murphey


    Full Text Available At the American Association of Applied Linguistics (AAAL 2011 conference, John Schumann described how Lee, Dina, Joaquin, Mates & Schumann’s (2010 interactional instinct unfolds between infants and caregivers such that learning an L1 is assured in normal development through emotional bonding between infants and caregivers which is substantiated by motivation, proficiency, and opportunities (all co-constructing concepts. In subsequent second language learning at an older age, these three characteristics are not environmentally and contextually assured, and this seems to account for a great part of the shortcomings of much of the late-L2 instruction in the world (Lee, Dina, Joaquin, Mates & Schumann, 2010.

  18. Bactobolin resistance is conferred by mutations in the L2 ribosomal protein. (United States)

    Chandler, Josephine R; Truong, Thao T; Silva, Patricia M; Seyedsayamdost, Mohammad R; Carr, Gavin; Radey, Matthew; Jacobs, Michael A; Sims, Elizabeth H; Clardy, Jon; Greenberg, E Peter


    Burkholderia thailandensis produces a family of polyketide-peptide molecules called bactobolins, some of which are potent antibiotics. We found that growth of B. thailandensis at 30°C versus that at 37°C resulted in increased production of bactobolins. We purified the three most abundant bactobolins and determined their activities against a battery of bacteria and mouse fibroblasts. Two of the three compounds showed strong activities against both bacteria and fibroblasts. The third analog was much less potent in both assays. These results suggested that the target of bactobolins might be conserved across bacteria and mammalian cells. To learn about the mechanism of bactobolin activity, we isolated four spontaneous bactobolin-resistant Bacillus subtilis mutants. We used genomic sequencing technology to show that each of the four resistant variants had mutations in rplB, which codes for the 50S ribosome-associated L2 protein. Ectopic expression of a mutant rplB gene in wild-type B. subtilis conferred bactobolin resistance. Finally, the L2 mutations did not confer resistance to other antibiotics known to interfere with ribosome function. Our data indicate that bactobolins target the L2 protein or a nearby site and that this is not the target of other antibiotics. We presume that the mammalian target of bactobolins involves the eukaryotic homolog of L2 (L8e). Currently available antibiotics target surprisingly few cellular functions, and there is a need to identify novel antibiotic targets. We have been interested in the Burkholderia thailandensis bactobolins, and we sought to learn about the target of bactobolin activity by mapping spontaneous resistance mutations in the bactobolin-sensitive Bacillus subtilis. Our results indicate that the bactobolin target is the 50S ribosome-associated L2 protein or a region of the ribosome affected by L2. Bactobolin-resistant mutants are not resistant to other known ribosome inhibitors. Our evidence indicates that bactobolins

  19. NFE2L2 pathway polymorphisms and lung function decline in chronic obstructive pulmonary disease. (United States)

    Sandford, Andrew J; Malhotra, Deepti; Boezen, H Marike; Siedlinski, Mateusz; Postma, Dirkje S; Wong, Vivien; Akhabir, Loubna; He, Jian-Qing; Connett, John E; Anthonisen, Nicholas R; Paré, Peter D; Biswal, Shyam


    An oxidant-antioxidant imbalance in the lung contributes to the development of chronic obstructive pulmonary disease (COPD) that is caused by a complex interaction of genetic and environmental risk factors. Nuclear erythroid 2-related factor 2 (NFE2L2 or NRF2) is a critical molecule in the lung's defense mechanism against oxidants. We investigated whether polymorphisms in the NFE2L2 pathway affected the rate of decline of lung function in smokers from the Lung Health Study (LHS)(n = 547) and in a replication set, the Vlagtwedde-Vlaardingen cohort (n = 533). We selected polymorphisms in NFE2L2 in genes that positively or negatively regulate NFE2L2 transcriptional activity and in genes that are regulated by NFE2L2. Polymorphisms in 11 genes were significantly associated with rate of lung function decline in the LHS. One of these polymorphisms, rs11085735 in the KEAP1 gene, was previously shown to be associated with the level of lung function in the Vlagtwedde-Vlaardingen cohort but not with decline of lung function. Of the 23 associated polymorphisms in the LHS, only rs634534 in the FOSL1 gene showed a significant association in the Vlagtwedde-Vlaardingen cohort with rate of lung function decline, but the direction of the association was not consistent with that in the LHS. In summary, despite finding several nominally significant polymorphisms in the LHS, none of these associations were replicated in the Vlagtwedde-Vlaardingen cohort, indicating lack of effect of polymorphisms in the NFE2L2 pathway on the rate of decline of lung function.

  20. Hypervirulent Chlamydia trachomatis Clinical Strain Is a Recombinant between Lymphogranuloma Venereum (L2) and D Lineages (United States)

    Somboonna, Naraporn; Wan, Raymond; Ojcius, David M.; Pettengill, Matthew A.; Joseph, Sandeep J.; Chang, Alexander; Hsu, Ray; Read, Timothy D.; Dean, Deborah


    ABSTRACT Chlamydia trachomatis is an obligate intracellular bacterium that causes a diversity of severe and debilitating diseases worldwide. Sporadic and ongoing outbreaks of lymphogranuloma venereum (LGV) strains among men who have sex with men (MSM) support the need for research on virulence factors associated with these organisms. Previous analyses have been limited to single genes or genomes of laboratory-adapted reference strain L2/434 and outbreak strain L2b/UCH-1/proctitis. We characterized an unusual LGV strain, termed L2c, isolated from an MSM with severe hemorrhagic proctitis. L2c developed nonfusing, grape-like inclusions and a cytotoxic phenotype in culture, unlike the LGV strains described to date. Deep genome sequencing revealed that L2c was a recombinant of L2 and D strains with conserved clustered regions of genetic exchange, including a 78-kb region and a partial, yet functional, toxin gene that was lost with prolonged culture. Indels (insertions/deletions) were discovered in an ftsK gene promoter and in the tarp and hctB genes, which encode key proteins involved in replication, inclusion formation, and histone H1-like protein activity, respectively. Analyses suggest that these indels affect gene and/or protein function, supporting the in vitro and disease phenotypes. While recombination has been known to occur for C. trachomatis based on gene sequence analyses, we provide the first whole-genome evidence for recombination between a virulent, invasive LGV strain and a noninvasive common urogenital strain. Given the lack of a genetic system for producing stable C. trachomatis mutants, identifying naturally occurring recombinants can clarify gene function and provide opportunities for discovering avenues for genomic manipulation. PMID:21540364

  1. Switches to English during French Service Encounters: Relationships with L2 French Speakers' Willingness to Communicate and Motivation (United States)

    McNaughton, Stephanie; McDonough, Kim


    This exploratory study investigated second language (L2) French speakers' service encounters in the multilingual setting of Montreal, specifically whether switches to English during French service encounters were related to L2 speakers' willingness to communicate or motivation. Over a two-week period, 17 French L2 speakers in Montreal submitted…

  2. Interplay of Languaging and Gameplay: Player-Game Interactions as Ecologies for Languaging and Situated L2 Development (United States)

    Ibrahim, Karim Hesham Shaker


    The field of game-mediated L2 learning has grown exponentially, and much has been discovered about the potentials of game-mediated interactions for L2 development, yet the fine-grained dynamics of player-game interactions and how they come to facilitate and afford L2 development are still largely underexplored. To address this gap in the…

  3. L2 English Intonation: Relations between Form-Meaning Associations, Access to Meaning, and L1 Transfer (United States)

    Ortega-Llebaria, Marta; Colantoni, Laura


    Although there is consistent evidence that higher levels of processing, such as learning the form-meaning associations specific to the second language (L2), are a source of difficulty in acquiring L2 speech, no study has addressed how these levels interact in shaping L2 perception and production of intonation. We examine the hypothesis of whether…

  4. Reading in L2 (English) and L1 (Persian): An Investigation into Reverse Transfer of Reading Strategies (United States)

    Talebi, Seyed Hassan


    This study investigates the effect of reading strategies instruction in L2 (English) on raising reading strategies awareness and use and reading ability of Iranian EFL learners in L2 (English) and L1 (Persian) as a result of transfer of reading strategies from L2 to L1. To this purpose, 120 students of intermediate and advanced English proficiency…

  5. The Role of L1 Conceptual and Linguistic Knowledge and Frequency in the Acquisition of L2 Metaphorical Expressions (United States)

    Türker, Ebru


    This study investigates how figurative language is processed by learners of a second language (L2). With an experiment testing L2 comprehension of figurative expressions in three categories, each combining shared and unshared first language (L1) and L2 lexical representations and conceptual representations in a different way, the study…

  6. Set-up of proportional counter L2 for 14C measurements with improved precision

    International Nuclear Information System (INIS)

    Goslar, T.; Pazdur, A.; Pazdur, M.F.; Walanus, A.; Zastawny, A.


    Radiocarbon dating with improved precision denotes determination of conventional radiocarbon dates with accuracy equal to ca ± 25 yr. The paper presents some fundamental data concerning construction and design of the proportional counter L2, the results of calibration of the counter, including detailed information on changes of the background counting rate. The counter L2 enables dating of samples up to 50 000 yr. For samples younger than 3000 yr the error of dating is equal to ca ± 25 yr. 4 figs., 1 tab., 9 refs. (author)


    Directory of Open Access Journals (Sweden)

    Michela Albizzati


    Full Text Available Può il film rivelarsi uno strumento utile a lezione di italiano L2? Quali sono i limiti ed i vantaggi dell’utilizzo di materiale audiovisivo autentico in aula? Come strutturare un’attività basata sulla visione di un film italiano in lingua originale? Quali strategie mette in atto l’apprendente per comprendere un film nella L2? “Il film a lezione di italiano L2: gli esami al cinema” cerca di rispondere a queste domande attraverso una riflessione sull’utilità del cinema a lezione e proponendo un’attività didattica basata sulla visione di sequenze tratte da film italiani. Considerando la pellicola come documento di civiltà, veicolo di una lingua viva e “in situazione” ed esperienza di apprendimento plurisensoriale, l’articolo mette in luce come l’apprendimento dell’italiano L2 possa trarre beneficio dall’utilizzo in aula di materiali audiovisivi autentici quali i film, se opportunamente selezionati e didattizzati. Dalla riflessione alla pratica: dopo aver identificato obiettivi, destinatari ed i loro bisogni linguistico-comunicativi, viene presentata un’attività basata sulla didattizzazione di tre sequenze che hanno come tema centrale l’esame universitario orale. Ponendo i bisogni linguistico-comunicativi dei discenti al centro si scoprirà che, se opportunamente didattizzato, un film o parte di esso può trasformarsi in materiale didattico estremamente utile ai fini dell’apprendimento di una L2, nonché fonte inesauribile di spunti a partire dai quali l’insegnante può creare attività didattiche originali e stimolanti non solo linguistiche ma anche interculturali. Movies during italian l2 lessons: exams at the cinemaAre movies useful tools during Italian L2 lessons? What are the limits and advantages of using authentic audio-visual materials in the classroom? How can an activity based on viewing an Italian film in the original language be structured? What strategies do learners use to understand movies in

  8. Phonological and Executive Working Memory in L2 Task-Based Speech Planning and Performance (United States)

    Wen, Zhisheng


    The present study sets out to explore the distinctive roles played by two working memory (WM) components in various aspects of L2 task-based speech planning and performance. A group of 40 post-intermediate proficiency level Chinese EFL learners took part in the empirical study. Following the tenets and basic principles of the…

  9. Web-Based Virtual Environments for Facilitating Assessment of L2 Oral Communication Ability (United States)

    Ockey, Gary J.; Gu, Lin; Keehner, Madeleine


    A growing number of stakeholders argue for the use of second language (L2) speaking assessments that measure the ability to orally communicate in real time. A Web-based virtual environment (VE) that allows live voice communication among individuals may have potential for aiding in delivering such assessments. While off-the-shelf voice…

  10. Does the Medium Really Matter in L2 Development? The Validity of Call Research Designs (United States)

    Cerezo, Luis; Baralt, Melissa; Suh, Bo-Ram; Leow, Ronald P.


    Currently, an increasing number of educational institutions are redefining second/foreign language (L2) classrooms by enhancing--or even replacing--traditional face-to-face (FTF) instruction with computer-assisted language learning (CALL). However, are these curricular decisions supported by research? Overall, a cursory review of empirical studies…

  11. The Use of Articles in L2 English: A Phraseological Perspective (United States)

    Lesniewska, Justyna


    While it is a well-known fact that speakers of article-less mother tongues, such as Polish, experience problems with articles in English, this study seeks to investigate the problem from a different perspective. Namely, it poses the question of whether the correct use of the article system of the L2 is indeed a purely grammatical task (as it is…

  12. Lexical statistics of competition in L2 versus L1 listening

    NARCIS (Netherlands)

    Cutler, A.


    Spoken-word recognition involves multiple activation of alternative word candidates and competition between these alternatives. Phonemic confusions in L2 listening increase the number of potentially active words, thus slowing word recognition by adding competitors. This study used a 70,000-word

  13. Applications of the Buckeye GTA Corpus for L2 teaching and research

    DEFF Research Database (Denmark)

    Hardman, Jocelyn; McCullough, Elizabeth

    The Buckeye GTA Corpus contains 9,664 L1 and L2 sentence productions by 89 talkers (27 American English, 19 Hindi, 23 Mandarin, & 20 Korean). A total of 5,696 sentences were read in English, with each talker contributing 64 sentences. Hindi, Mandarin, and Korean talkers also read 64 sentences each...

  14. Effects of Audiovisual Media on L2 Listening Comprehension: A Preliminary Study in French (United States)

    Becker, Shannon R.; Sturm, Jessica L.


    The purpose of the present study was to determine whether integrating online audiovisual materials into the listening instruction of L2 French learners would have a measurable impact on their listening comprehension development. Students from two intact sections of second-semester French were tested on their listening comprehension before and…

  15. The effects of captioning texts and caption ordering on L2 listening comprehension and vocabulary learning

    Directory of Open Access Journals (Sweden)

    Fatemeh Alikhani


    Full Text Available This study investigated the effects of captioned texts on second/foreign (L2 listening comprehension and vocabulary gains using a computer multimedia program. Additionally, it explored the caption ordering effect (i.e. captions displayed during the first or second listening, and the interaction of captioning order with the L2 proficiency level of language learners in listening comprehension and vocabulary performance. To these ends, a computer software program was designed and 200 EFL learners (100 high-intermediate and 100 low-intermediate level students were asked to participate in the experiment. They were randomly assigned into four groups: captioned (listening to texts twice with captions, noncaptioned (listening to texts twice without captions, first captioned (listening to texts first with captions and then without captions, and second captioned (listening to texts first without captions and then with captions groups. They listened to four audio texts (i.e. short stories twice and took the listening and vocabulary tests, administered through the software. Results from t-tests and two-way ANOVAs showed that the captioned stories were more effective than the non-captioned ones. Moreover, the caption ordering had no significant effect on the participants' L2 listening comprehension and vocabulary performance. Finally, L2 proficiency level differences did not affect performance derived from caption ordering.

  16. Questioning English Standards: Learner Attitudes and L2 Choices in Norway (United States)

    Rindal, Ulrikke


    This study investigates attitudes towards varieties of English among Norwegian adolescent learners and assesses the role of social evaluation for second language (L2) pronunciation choices by combining a verbal guise test with speaker commentary and reports of language choices. The results suggest that while American English is the most accessible…

  17. A Comparative Study of Video Presentation Modes in Relation to L2 Listening Success (United States)

    Li, Chen-Hong


    Video comprehension involves interpreting both sounds and images. Research has shown that processing an aural text with relevant pictorial information effectively enhances second/foreign language (L2) listening comprehension. A hypothesis underlying this mixed-methods study is that a visual-only silent film used as an advance organiser to activate…

  18. Computer-Mediated Communication (CMC) in L2 Oral Proficiency Development: A Meta-Analysis (United States)

    Lin, Huifen


    The ever growing interest in the development of foreign or second (L2) oral proficiency in a computer-mediated communication (CMC) classroom has resulted in a large body of studies looking at both the direct and indirect effects of CMC interventions on the acquisition of oral competences. The present study employed a quantitative meta-analytic…

  19. Leveling L2 Texts through Readability: Combining Multilevel Linguistic Features with the CEFR (United States)

    Sung, Yao-Ting; Lin, Wei-Chun; Dyson, Scott Benjamin; Chang, Kuo-En; Chen, Yu-Chia


    Selecting appropriate texts for L2 (second/foreign language) learners is an important approach to enhancing motivation and, by extension, learning. There is currently no tool for classifying foreign language texts according to a language proficiency framework, which makes it difficult for students and educators to determine the precise…

  20. Lexical Difficulty--Using Elicited Imitation to Study Child L2 (United States)

    Campfield, Dorota E.


    This paper reports a post-hoc analysis of the influence of lexical difficulty of cue sentences on performance in an elicited imitation (EI) task to assess oral production skills for 645 child L2 English learners in instructional settings. This formed part of a large-scale investigation into effectiveness of foreign language teaching in Polish…

  1. The Effect of Lexical Coverage and Dictionary Use on L2 Reading Comprehension (United States)

    Prichard, Caleb; Matsumoto, Yuko


    This study aims to further understand the role of lexical coverage on L2 reading comprehension. It examines test scores of learners at or near the 90-95% coverage level to determine if this coverage range allows for comprehension of authentic texts. The findings suggest that 92-93% may be a threshold mark at which understanding of a text…

  2. Breadth and Depth of Vocabulary Knowledge and Their Effects on L2 Vocabulary Profiles (United States)

    Bardakçi, Mehmet


    Breadth and depth of vocabulary knowledge have been studied from many different perspectives, but the related literature lacks serious studies dealing with their effects on vocabulary profiles of EFL learners. In this paper, with an aim to fill this gap, the relative effects of breadth and depth of vocabulary knowledge on L2 vocabulary profiles…

  3. L^2-Betti numbers of rigid C*-tensor categories and discrete quantum groups

    DEFF Research Database (Denmark)

    Kyed, David; Raum, Sven; Vaes, Stefaan


    of the representation category $Rep(G)$ and thus, in particular, invariant under monoidal equivalence. As an application, we obtain several new computations of $L^2$-Betti numbers for discrete quantum groups, including the quantum permutation groups and the free wreath product groups. Finally, we obtain upper bounds...

  4. Spoken Language Activation Alters Subsequent Sign Language Activation in L2 Learners of American Sign Language (United States)

    Williams, Joshua T.; Newman, Sharlene D.


    A large body of literature has characterized unimodal monolingual and bilingual lexicons and how neighborhood density affects lexical access; however there have been relatively fewer studies that generalize these findings to bimodal (M2) second language (L2) learners of sign languages. The goal of the current study was to investigate parallel…

  5. Student Teachers' Cognition about L2 Pronunciation Instruction: A Case Study (United States)

    Burri, Michael


    In view of the minimal attention pronunciation teacher preparation has received in second language (L2) teacher education, this study examined the cognition (i.e. beliefs, thoughts, attitudes and knowledge) development of 15 student teachers during a postgraduate subject on pronunciation pedagogy offered at an Australian tertiary institution.…

  6. On the Impact of L2 Speech Rhythm on Syntactic Ambiguity Resolution (United States)

    Roncaglia-Denissen, M. Paula; Schmidt-Kassow, Maren; Heine, Angela; Kotz, Sonja A.


    In an event-related potential (ERP) study we investigated the role of age of acquisition (AoA) on the use of second language rhythmic properties during syntactic ambiguity resolution. Syntactically ambiguous sentences embedded in rhythmically regular and irregular contexts were presented to Turkish early and late second language (L2) learners of…

  7. The Development of Individual Learners in an L2 Listening Strategies Course (United States)

    Yeldham, Michael; Gruba, Paul


    This study examined the idiosyncratic development of second language (L2) learners in a listening strategies course. The progress of four Taiwanese EFL learners was examined longitudinally through a variety of quantitative and qualitative techniques as the learners participated in a course combining direct instruction of strategies with their…

  8. L2 Learners' Recognition of Unfamiliar Idioms Composed of Familiar Words (United States)

    Kim, Choonkyong


    Most second language (L2) learners are aware of the importance of vocabulary, and this awareness usually directs their attention to learning new words. By contrast, learners do not often recognise unfamiliar idioms if all the compositional parts look familiar to them such as "turn the corner" or "carry the day." College-level…

  9. Quantitative and Qualitative Aspects of L1 (Swedish) and L2 (English) Idiom Comprehension (United States)

    Karlsson, Monica


    In the present investigation, 15 first term university students were faced with 80 context-based idioms in English (L2) and Swedish (L1) respectively, 30 of which were in the source domain of animals, commonly used in both languages, and asked to explain their meaning. The idioms were of varying frequency and transparency. Three main research…

  10. The Role of Statistical Learning and Working Memory in L2 Speakers' Pattern Learning (United States)

    McDonough, Kim; Trofimovich, Pavel


    This study investigated whether second language (L2) speakers' morphosyntactic pattern learning was predicted by their statistical learning and working memory abilities. Across three experiments, Thai English as a Foreign Language (EFL) university students (N = 140) were exposed to either the transitive construction in Esperanto (e.g., "tauro…

  11. Teaching L2 Spanish Sociopragmatics through Concepts: A Classroom-Based Study (United States)

    van Compernolle, Rémi A.; Gomez-Laich, Maria Pia; Weber, Ashley


    This study explores the teaching of second language (L2) Spanish sociopragmatics through concept-based pragmatics instruction (van Compernolle, 2014). The concepts of self-presentation, social distance, and power were the focus of a pedagogical enrichment program in 2 sections of a beginning-level Spanish class at a northeastern U.S. university.…

  12. Exploring the Relationship between Reading Strategy Use and Multiple Intelligences among Successful L2 Readers (United States)

    Mirzaei, Azizullah; Rahimi Domakani, Masoud; Heidari, Najmeh


    Over the years, the multiple intelligences theory (MIT) proposed by Howard Gardner has renewed interest in learners' use of effective learning strategies and produced interesting results. This MIT-oriented study investigated the role of successful L2 readers' multiple intelligences in their effective use of reading strategies. To this end, a TOEFL…

  13. A Collaboration-Mediated Exploration of Nonnative L2 Teachers' Cognition of Language Teaching Methodology (United States)

    Tajeddin, Zia; Aryaeian, Nafeeseh


    The present study sought to investigate nonnative L2 teachers' cognition of teaching methodology based on their collaborative talks. Participants were 12 nonnative EFL teachers categorized into three collaborative discussion groups by their teaching experience. Collaborative discussions were aimed at exploring the participants' cognition of…

  14. The Effect of Emotional Intelligence Awareness-Raising Activities on L2 Motivation (United States)

    Barzegar, Reza; Sadr, Sajjad Aref


    This article reports a study investigating the effect of emotional intelligence (EI) awareness-raising on Iranian university students' overall as well as variable-specific L2 motivation. The 136 participants (107 males, 29 females) were divided into a control group and an experimental group, both of which completed the same motivation…

  15. Partial Word Knowledge: Frontier Words in the L2 Mental Lexicon (United States)

    Zareva, Alla


    The study set out to examine the partial word knowledge of native speakers, L2 advanced, and intermediate learners of English with regard to four word features from Richards' (1976) taxonomy of aspects describing what knowing a word entails. To capture partial familiarity, the participants completed in writing a test containing low and mid…

  16. The Effect of Online Translators on L2 Writing in French (United States)

    O'Neill, Errol Marinus


    Online translation (OT) sites such as Free Translation and Babel Fish are freely available to the general public and purport to convert inputted text, from single words to entire paragraphs, instantly from one language to another. Discussion in the literature about OT for second-language (L2) acquisition has generally focused either on the…

  17. Metacognitive Online Reading Strategy Use: Readers' Perceptions in L1 and L2 (United States)

    Taki, Saeed


    This study aimed to explore whether first-language (L1) readers of different language backgrounds would employ similar metacognitive online reading strategies and whether reading online in a second language (L2) could be influenced by L1 reading strategies. To this end, 52 Canadian college students as English L1 readers and 38 Iranian university…

  18. Gender Differences in Compulsory School Pupils' L2 Self-Concepts: A Longitudinal Study (United States)

    Henry, Alastair


    Drawing on personality psychology research, Dornyei and his colleagues have recently developed an approach to understanding L2 motivation that positions the learner's self-recognition as a potential communicator in another language at its core, thus marking a break from the established social psychology paradigm. In this article it is argued that,…

  19. L2 Vocabulary Acquisition in Children: Effects of Learning Method and Cognate Status (United States)

    Tonzar, Claudio; Lotto, Lorella; Job, Remo


    In this study we investigated the effects of two learning methods (picture- or word-mediated learning) and of word status (cognates vs. noncognates) on the vocabulary acquisition of two foreign languages: English and German. We examined children from fourth and eighth grades in a school setting. After a learning phase during which L2 words were…

  20. On the L2 acquisition of Spanish-subject verb inversion

    NARCIS (Netherlands)

    Guerra Rivera, Alexia; Coopmans, Peter; Baauw, Sergio


    This study explores the acquisition of Spanish subject-verb inversion in wh-questions by Dutch L2 learners. The optional or obligatory application of this rule in Spanish wh-questions depends on the argument versus adjunct status of the wh-element. In Dutch,subject-verb inversionis obligatory in

  1. Teaching Cases to L2 German and Russian Learners: A Cognitive Approach (United States)

    Lysinger, Diana


    This dissertation offers a Cognitive Grammar-based approach to teaching cases to L2 German and Russian students and examines the impacts of various methods of case instruction in beginning German and Russian language classes. A CG-based explanation of cases was already proposed by some CG theorists (i.e., Langacker 1987, 1991; Smith 1987, Janda…

  2. Teaching, Learning, and Developing L2 French Sociolinguistic Competence: A Sociocultural Perspective (United States)

    van Compernolle, Remi A.; Williams, Lawrence


    The study reported in this article investigates the development of sociolinguistic competence among second-year (US university-level) L2 learners of French who were given systematic instruction on sociolinguistic variation as part of their normal coursework. We focus on the variable use of the negative morpheme "ne" in verbal negation. Drawing…

  3. The Design of Morphological/Linguistic Data in L1 and L2 ...

    African Journals Online (AJOL)


    learners' MA of an L1 or L2 can be measured (and, as an extension to this, that users' and .... and they could activate these strategies and skills when confronted with new .... cussion of a wide range of morphological phenomena in English.

  4. Topological analysis of Chlamydia trachomatis L2 outer membrane protein 2

    DEFF Research Database (Denmark)

    Mygind, P; Christiansen, Gunna; Birkelund, Svend


    Using monospecific polyclonal antisera to different parts of Chlamydia trachomatis L2 outer membrane protein 2 (Omp2), we show that the protein is localized at the inner surface of the outer membrane. Omp2 becomes immunoaccessible when Chlamydia elementary bodies are treated with dithiothreitol...

  5. Effects of Help Options in a Multimedia Listening Environment on L2 Vocabulary Acquisition (United States)

    Mohsen, Mohammed Ali


    Several types of help options have been incorporated into reading and listening comprehension activities to aid second language (L2) vocabulary acquisition. Textbook authors, teachers, and sometimes even students may pick and choose which help options they wish to use. In this paper, I investigate the effects of two help options in a multimedia…

  6. An Experimental Study on the Effects of Different Reading Tasks on L2 Vocabulary Acquisition (United States)

    Xu, Jianping


    This empirical study was undertaken to test the Involvement Load Hypothesis (Laufer and Hulstijn, 2001) by examining the impact of three tasks on vocabulary acquisition. It was designed to test and develop the involvement load hypothesis by examining the impact of different reading tasks on the L2 vocabulary acquisition. The results show that…

  7. Does Morphology Play an Important Role in L2 Chinese Vocabulary Acquisition? (United States)

    Zhang, Haomin


    The present study examined the role of morphological awareness in second language (L2) Chinese vocabulary acquisition through an investigation of linguistic universality and specificity underlying morphological awareness. Morphological awareness in this study was conceptualized as a universal and sharable cognitive resource as well as a…

  8. Incidental L2 Vocabulary Acquisition "from" and "while" Reading: An Eye-Tracking Study (United States)

    Pellicer-Sánchez, Ana


    Previous studies have shown that reading is an important source of incidental second language (L2) vocabulary acquisition. However, we still do not have a clear picture of what happens when readers encounter unknown words. Combining offline (vocabulary tests) and online (eye-tracking) measures, the incidental acquisition of vocabulary knowledge…

  9. Using Songs to Enhance L2 Vocabulary Acquisition in Preschool Children (United States)

    Coyle, Yvette; Gómez Gracia, Remei


    This article looks at the effects of a teaching sequence of song-based activities on the L2 vocabulary acquisition of a group of five-year-old Spanish child EFL learners. Twenty-five preschool children received three 30-minute lessons organized around the presentation and practice of a well-known children's song. Vocabulary picture tests were…

  10. Analysis of proteins in Chlamydia trachomatis L2 outer membrane complex, COMC

    DEFF Research Database (Denmark)

    Birkelund, Svend; Morgan-Fisher, Marie; Timmerman, Evy


    The protein composition and N-terminal sequences of proteins in the outer membrane of Chlamydia trachomatis L2 were analysed following isolation of N-terminal peptides using combined fractional diagonal chromatography and identification by liquid chromatography tandem MS. Acetylation of primary a...

  11. Negotiating Multiple Audiences of L2 Learners on Facebook: Navigating Parallel Realities (United States)

    Shafie, Latisha Asmaak; Yaacob, Aizan; Singh, Paramjit Kaur A/P Karpal


    As social network sites have become popular with university students, it is easier to understand how students employ social network sites seamlessly in their academic and personal lives. L2 learners often employ Facebook to improve their English language proficiency by communicating with their native and non-native English speakers. Facebook is…

  12. Morphological Family Size effects in L1 and L2 processing: An electrophysiological study

    NARCIS (Netherlands)

    Mulder, K.; Schreuder, R.; Dijkstra, A.F.J.


    The present study examined Morphological Family Size effects in first and second language processing. Items with a high or low Dutch (L1) Family Size were contrasted in four experiments involving Dutch–English bilinguals. In two experiments, reaction times (RTs) were collected in English (L2) and

  13. Meaning-focused vs Form-focused L2 Instruction: Implications for ...

    African Journals Online (AJOL)


    focus-on-meaning approach to English language instruction) compare with ... L2 use. Proponents of this view are concerned with the question of how this conversion ... processing, it may draw learners' attention to "notice" the form of the target ...

  14. Embedded "wh"-Questions in L2 English in India: Inversion as a Main Clause Phenomenon (United States)

    Stringer, David


    This corpus study brings a second language (L2) research perspective, insights from generative grammar, and new empirical evidence to bear on a long-accepted claim in the World Englishes literature--namely, that inversion with "wh"-movement in colloquial Indian English is obligatory in embedded clauses and impossible in main clauses. It…

  15. Authentic L2 Interactions as Material for a Pragmatic Awareness-Raising Activity (United States)

    Cheng, Tsui-Ping


    This study draws on conversation analysis to explore the pedagogical possibility of using audiovisual depictions of authentic disagreement sequences from L2 interactions as sources for an awareness-raising activity in an English as a Second Language (ESL) classroom. Video excerpts of disagreement sequences collected from two ESL classes were used…

  16. Working Smarter, Not Working Harder: Revisiting Teacher Feedback in the L2 Writing Classroom (United States)

    Lee, Icy


    Although second language (L2) teachers spend a significant amount of time marking students' writing, many of them feel that their efforts do not pay off. While students want teachers to give them feedback on their writing and value teacher feedback, they might experience feelings of frustration and confusion once they receive it. What is amiss in…

  17. Arguing in L2: Discourse Structure and Textual Metadiscourse in Philippine Newspaper Editorials (United States)

    Tarrayo, Veronico N.; Duque, Marie Claire T.


    This study described the discourse structure and textual metadiscourse in newspaper editorials in the Philippines where English is used as a second language or L2. Specifically, it sought answers to the following questions: (1) What discourse features characterize the structure of the following parts of Philippine newspaper editorials--orientation…

  18. Successful Learners of Irish as an L2: Motivation, Identity and Linguistic Mudes

    Directory of Open Access Journals (Sweden)

    Petit Kevin


    Full Text Available This article presents the results of a small-scale research conducted for a master’s thesis on the motivation to learn Irish on the part of university students and members of the Gaelic society An Cumann Gaelach. In the light of questionnaires’ results and interviews, the emphasis is placed on the links between motivation, identity, and potential key moments in learners’ lives. Using an AMTB-type questionnaire (n=45, the author puts to the test Dörnyei’s Motivational Self System theory (2005 in the context of the learning of Irish by looking at the correlation between the motivational intensity of 45 students and six variables (Ideal L2 Self, Ought to Self, Ideal L2 Community, Instrumentality, Parental encouragement, and Role of teachers. The notion of Ideal L2 Self, or the capacity to picture oneself speaking an L2 in the future, clearly appears to be strongly correlated with the respondents’ motivational intensity (r=.75 p<.01, in accordance with Dörnyei’s model. However results concerning extrinsic factors differ from previous research, putting forward distinctive features of the learning of minority languages. The second phase of the research looks at the language learning narratives of three An Cumann Gaelach’s members through the qualitative analysis of three interview transcripts. The results clearly show that time spent in Irish summer colleges are linguistic mudes (Pujolar and Puigdevall 2015, or key-moments, which triggered the interest in the language for the three students interviewed.

  19. Connecting Reading and Writing Using Children's Literature in the University L2 Classroom (United States)

    Leal, Priscila


    This article investigates the potential benefits of using children's literature in adult second language (L2) classrooms. A short-term, intensive university course for English reading and writing was designed incorporating children's literature into the curriculum. The author describes the course and discusses how children's literature can be used…

  20. Automatic detection of frequent pronunciation errors made by L2-learners

    NARCIS (Netherlands)

    Truong, K.P.; Neri, A.; Wet, F. de; Cucchiarini, C.; Strik, H.


    In this paper, we present an acoustic-phonetic approach to automatic pronunciation error detection. Classifiers using techniques such as Linear Discriminant Analysis and Decision Trees were developed for three sounds that are frequently pronounced incorrectly by L2-learners of Dutch: /a/, /y/ and

  1. Reading Strategies in a L2: A Study on Machine Translation (United States)

    Karnal, Adriana Riess; Pereira, Vera Vanmacher


    This article aims at understanding cognitive strategies which are involved in reading academic texts in English as a L2/FL. Specifically, we focus on reading comprehension when a text is read either using Google translator or not. From this perspective we must consider the reading process in its complexity not only as a decoding process. We follow…

  2. The Use of Paraphrase in Summary Writing: A Comparison of L1 and L2 Writers (United States)

    Keck, Casey


    Paraphrasing is considered by many to be an important skill for academic writing, and some have argued that the teaching of paraphrasing might help students avoid copying from source texts. Few studies, however, have investigated the ways in which both L1 and L2 academic writers already use paraphrasing as a textual borrowing strategy when…

  3. Requirements for an "ideal" bilingual L1 →L2 translation- oriented ...

    African Journals Online (AJOL)

    The major aim of this article is to outline the requirements for an "ideal" bilingual L1 →L2 dictionary of the general vocabulary specifically designed for the purposes of professional translation. The article challenges three commonly accepted beliefs: (a) a bilingual dictionary equals a translation dictionary; (b) a bilingual ...

  4. Developing L2 Listening Fluency through Extended Listening-Focused Activities in an Extensive Listening Programme (United States)

    Chang, Anna C-S.; Millett, Sonia


    This study investigates the effects on developing L2 listening fluency through doing extended listening-focused activities after reading and listening to audio graded readers. Seventy-six EFL university students read and listened to a total of 15 graded readers in a 15-week extensive listening programme. They were divided into three groups (Group…

  5. Eventive and Stative Passives in Spanish L2 Acquisition: A Matter of Aspect (United States)

    De Garavito, Joyce Bruhn; Valenzuela, Elena


    This paper reports on an empirical study that examined knowledge of eventive and stative passives in the L2 Spanish grammar of L1 speakers of English. Although the two types of passive exist in English, the difference between them is not signaled in any specific way. In Spanish, in contrast, the distinction is marked by the choice of copula: "ser"…

  6. The Multi-Feature Hypothesis: Connectionist Guidelines for L2 Task Design (United States)

    Moonen, Machteld; de Graaff, Rick; Westhoff, Gerard; Brekelmans, Mieke


    This study focuses on the effects of task type on the retention and ease of activation of second language (L2) vocabulary, based on the multi-feature hypothesis (Moonen, De Graaff, & Westhoff, 2006). Two tasks were compared: a writing task and a list-learning task. It was hypothesized that performing the writing task would yield higher…

  7. Measuring Group Work Dynamics and Its Relation with L2 Learners' Task Motivation and Language Production (United States)

    Poupore, Glen


    While learners of a second language (L2) are increasingly interacting in small groups as part of a communicative methodological paradigm, very few studies have investigated the social dynamics that occur in such groups. The aim of this study is to introduce a group work dynamic measuring instrument and to investigate the relationship between group…

  8. NFE2L2 pathway polymorphisms and lung function decline in chronic obstructive pulmonary disease

    NARCIS (Netherlands)

    Sandford, Andrew J.; Malhotra, Deepti; Boezen, H. Marike; Siedlinski, Mateusz; Postma, Dirkje S.; Wong, Vivien; Akhabir, Loubna; He, Jian-Qing; Connett, John E.; Anthonisen, Nicholas R.; Pare, Peter D.; Biswal, Shyam


    Sandford AJ, Malhotra D, Boezen HM, Siedlinski M, Postma DS, Wong V, Akhabir L, He JQ, Connett JE, Anthonisen NR, Pare PD, Biswal S. NFE2L2 pathway polymorphisms and lung function decline in chronic obstructive pulmonary disease. Physiol Genomics 44: 754-763, 2012. First published June 12, 2012;

  9. The Unfairness of Equal Treatment: Objectivity in L2 Testing and Dynamic Assessment (United States)

    Lantolf, James P.; Poehner, Matthew E.


    This paper considers dynamic assessment (DA) as it relates to second language (L2) development. DA is grounded in Vygotsky's (1987) sociocultural theory of mind, which holds that human consciousness emerges as a result of participation in culturally organized social activities where mediation plays a key role in guiding development. In DA, the…

  10. Working Memory Capacity and L2 University Students' Comprehension of Linear Texts and Hypertexts (United States)

    Fontanini, Ingrid; Tomitch, Leda Maria Braga


    The aim of this study was to investigate the relationship between working memory capacity and L2 reading comprehension of both linear texts and hypertexts. Three different instruments were used to measure comprehension (recall, comprehension questions and perception of contradictions) and the Reading Span Test (Daneman & Carpenter, 1980) was…

  11. The Role of Cognitive and Affective Factors in Measures of L2 Writing (United States)

    Zabihi, Reza


    This study investigates the direct and/or indirect effects of some cognitive (working memory capacity) and affective (writing anxiety and writing self-efficacy) variables on the complexity, accuracy, and fluency (CAF) of second language (L2) learners' writings. To achieve this goal, 232 upper-intermediate English learners performed an automated…

  12. Exploring Collaboratively Written L2 Texts among First-Year Learners of German in Google Docs (United States)

    Abrams, Zsuzsanna


    Grounded in research on collaborative writing and computer-mediated writing the present study examines the computer-mediated collaborative writing process among first-year learners of German as a second language (L2) at a US university. The data come from 28 first-year learners of German at a US university, who wrote hypothesized endings to a…

  13. Developmental Asynchrony in the Acquisition of Subject Properties in Child L2 English and Spanish (United States)

    Pladevall-Ballester, Elisabet


    Given that L1A of subject properties in non-null subject languages emerges later than that of null subject languages, this study aims at determining to what extent the same pattern of acquisition is observed in early child L2A in bilingual immersion settings where English and Spanish are both source and target languages. Using an elicited oral…

  14. Genome Sequences of Four Subcluster L2 Mycobacterium Phages, Finemlucis, Miley16, Wilder, and Zakai


    Herren, Christopher D.; Peister, Alexandra; Breton, Timothy S.; Hill, Maggie S.; Anderson, Marcy S.; Chang, Adeline W.; Klein, Sydney B.; Thornton, Mackenzie M.; Vars, Stacy J.; Wagner, Kasey E.; Wiebe, Paige L.; Williams, Thomas G.; Yanez, Coraima P.; Ackles, Jasanta M.; Artis, Darius


    ABSTRACT Four subcluster L2 mycobacteriophages, Finemlucis, Miley16, Wilder, and Zakai, that infect Mycobacterium smegmatis mc2155 were isolated. The four phages are closely related to each other and code for 12 to 14 tRNAs and 130 to 132 putative protein-coding genes, including tyrosine integrases, cro, immunity repressors, and excise genes involved in the establishment of lysogeny.

  15. L(2, 1-Labelings of Some Families of Oriented Planar Graphs

    Directory of Open Access Journals (Sweden)

    Sen Sagnik


    Full Text Available In this paper we determine, or give lower and upper bounds on, the 2-dipath and oriented L(2, 1-span of the family of planar graphs, planar graphs with girth 5, 11, 16, partial k-trees, outerplanar graphs and cacti.

  16. Using Multimedia Vocabulary Annotations in L2 Reading and Listening Activities (United States)

    Jing Xu


    This paper reviews the role of multimedia vocabulary annotation (MVA) in facilitating second language (L2) reading and listening activities. It examines the multimedia learning and multimedia language learning theories that underlie the MVA research, synthesizes the findings on MVA in the last decade, and identifies three underresearched areas on…

  17. Characterization Results for the L(2, 1, 1-Labeling Problem on Trees

    Directory of Open Access Journals (Sweden)

    Zhang Xiaoling


    Full Text Available An L(2, 1, 1-labeling of a graph G is an assignment of non-negative integers (labels to the vertices of G such that adjacent vertices receive labels with difference at least 2, and vertices at distance 2 or 3 receive distinct labels. The span of such a labelling is the difference between the maximum and minimum labels used, and the minimum span over all L(2, 1, 1-labelings of G is called the L(2, 1, 1-labeling number of G, denoted by λ2,1,1(G. It was shown by King, Ras and Zhou in [The L(h, 1, 1-labelling problem for trees, European J. Combin. 31 (2010 1295–1306] that every tree T has Δ2(T − 1 ≤ λ2,1,1(T ≤ Δ2(T, where Δ2(T = maxuv∈E(T(d(u + d(v. And they conjectured that almost all trees have the L(2, 1, 1-labeling number attain the lower bound. This paper provides some sufficient conditions for λ2,1,1(T = Δ2(T. Furthermore, we show that the sufficient conditions we provide are also necessary for trees with diameter at most 6.

  18. A hydrogenosomal [Fe]-hydrogenase from the anaerobic chytrid Neocallimastix sp L2

    NARCIS (Netherlands)

    Voncken, Frank G.J.; Boxma, Brigitte; Hoek, Angela H.A.M. van; Akhmanova, Anna S.; Vogels, Godfried D.; Huynen, Martijn; Veenhuis, Marten; Hackstein, Johannes H.P.


    The presence of a [Fe]-hydrogenase in the hydrogenosomes of the anaerobic chytridiomycete fungus Neocallimastix sp. L2 has been demonstrated by immunocytochemistry, subcellular fractionation, Western-blotting, and measurements of hydrogenase activity in the presence of various concentrations of

  19. Learning English with "The Sims": Exploiting Authentic Computer Simulation Games for L2 Learning (United States)

    Ranalli, Jim


    With their realistic animation, complex scenarios and impressive interactivity, computer simulation games might be able to provide context-rich, cognitively engaging virtual environments for language learning. However, simulation games designed for L2 learners are in short supply. As an alternative, could games designed for the mass-market be…

  20. Cognitive Style and Reading Comprehension in L1 and L2. (United States)

    Vivaldo-Lima, Javier

    This paper presents the results of a research study carried out with Mexican college students to analyze the relationship between readers' cognitive styles (field dependent/independent) and their performance at different levels of written discourse processing in Spanish (L1) and English (L2). The sample for the study included 452 undergraduate…

  1. Roles of Position, Stress, and Proficiency in L2 Children's Spelling: A Developmental Perspective (United States)

    Hong, Su Chin; Chen, Shu Hui


    This study investigated the roles of phoneme position, stress, and proficiency in L2 spelling development by Taiwanese students learning English as a Foreign Language (EFL), an alphabetic writing system typologically different from the learners' L1 logographic system. Structured nonword spelling tests were administered to EFL sixth-graders with…

  2. Effects of Textual Enhancement and Input Enrichment on L2 Development (United States)

    Rassaei, Ehsan


    Research on second language (L2) acquisition has recently sought to include formal instruction into second and foreign language classrooms in a more unobtrusive and implicit manner. Textual enhancement and input enrichment are two techniques which are aimed at drawing learners' attention to specific linguistic features in input and at the same…

  3. How Iranian Instructors Teach L2 Pragmatics in Their Classroom Practices? A Mixed-Methods Approach (United States)

    Muthasamy, Paramasivam; Farashaiyan, Atieh


    This study examined the teaching approaches and techniques that Iranian instructors utilize for teaching L2 pragmatics in their classroom practices. 238 Iranian instructors participated in this study. The data for this study were accumulated through questionnaire and semi-structured interviews. In terms of the instructional approaches, both the…

  4. Validity Argument for Assessing L2 Pragmatics in Interaction Using Mixed Methods (United States)

    Youn, Soo Jung


    This study investigates the validity of assessing L2 pragmatics in interaction using mixed methods, focusing on the evaluation inference. Open role-plays that are meaningful and relevant to the stakeholders in an English for Academic Purposes context were developed for classroom assessment. For meaningful score interpretations and accurate…

  5. The Effect of Focus on Form and Task Complexity on L2 Learners' Oral Task Performance (United States)

    Salimi, Asghar


    Second Language learners' oral task performance has been one of interesting and research generating areas of investigations in the field of second language acquisition specially, task-based language teaching and learning. The main purpose of the present study is to investigate the effect of focus on form and task complexity on L2 learners' oral…

  6. Learning English as an L2 in the Global Context: Changing English, Changing Motivation (United States)

    Sung, Chit Cheung Matthew


    As the English language has become a global lingua franca today, it is not surprising that changes in attitudes and perceptions towards learning English in the international context have taken place at the same time. In this paper, I critically examine the notion of "integrative motivation" in the literature of second language (L2)…

  7. Military and Civilian L2 Instructors: Decoding Perceptions of U.S. Service Academy Cadets (United States)

    Miller, Zachary F.


    This study examined whether cadets at a U.S. service academy perceived attitudinal differences toward their military and civilian L2 instructors along three variables: foreign language expertise, communicative anxiety, and relatability. Cadets' proficiency levels (divided by beginning and intermediate classes) and current instructor (civilian or…

  8. Synthesis of L-2-amino-8-oxodecanoic acid: an amino acid component of apicidins


    Linares de la Morena, María Lourdes; Agejas Chicharro, Francisco Javier; Alajarín Ferrández, Ramón; Vaquero López, Juan José; Álvarez-Builla Gómez, Julio


    The synthesis Of L-2-amino-8-oxodecanoic acid (Aoda) is described. This is a rare amino acid component of apicidins, a family of new cyclic tetrapeptides, inhibitors of histone deacetylase. Aoda was synthesised in seven steps from L-glutamic acid along with some derivatives. Universidad de Alcalá Fundación General de la Universidad de Alcalá FEDER


    Indian Academy of Sciences (India)


    (iii) If α¯β ∈ H∞ then ||Sαβ|| = max{||α||∞,||β||∞. } ... (iii) Since α¯β ∈ H∞, for all f ∈ L2 we have 〈αPf,βQf〉 = 〈α¯β,PfQf〉 = 0. Thus ...... Birkhuser, Basel (1992).

  10. The Development of L2 Fluency during Study Abroad: A Cross-Language Study (United States)

    Di Silvio, Francesca; Diao, Wenhao; Donovan, Anne


    Examining speech samples from 75 American university students learning 1 of 3 languages (Mandarin, Russian, and Spanish), this article reports on a study of second language (L2) learners' oral fluency development and its relationship with their gains in holistic proficiency ratings during a semester abroad. In study abroad research, there is a…

  11. Interpreting Definiteness in a Second Language without Articles: The Case of L2 Russian (United States)

    Cho, Jacee; Slabakova, Roumyana


    This article investigates the second language (L2) acquisition of two expressions of the semantic feature [definite] in Russian, a language without articles, by English and Korean native speakers. Within the Feature Reassembly approach (Lardiere, 2009), Slabakova (2009) has argued that reassembling features that are represented overtly in the…

  12. Effects of Interactive Chat versus Independent Writing on L2 Learning (United States)

    Tare, Medha; Golonka, Ewa M.; Vatz, Karen; Bonilla, Carrie L.; Crooks, Carolyn; Strong, Rachel


    This study examines the importance of interaction for second language (L2) acquisition by analyzing outcomes from two types of out-of-class activities. The study compared: (a) interactive homework, completed via text chat, and (b) individual homework, completed via independent writing. In a between-subjects design, participants in two…

  13. The Impact of Blended e-Learning on Undergraduate Academic Essay Writing in English (L2) (United States)

    Ferriman, Nicholas


    This paper describes a quasi-experimental study into the impact of a blended e-learning environment on academic writing assignments in English (L2) at a Thai international college. An experimental group of 15 students used an on-line bulletin board, as well as face-to-face (F2F) communication in class, to share information for essay topics they…

  14. Frame properties of wave packet systes in L^2 (R^d)

    DEFF Research Database (Denmark)

    Christensen, Ole; Rahimi, Asghar


    Extending work by Hernandez, Labate and Weiss, we present a sufficent condition for a generalized shift-invariant system to be a Bessel sequence or even a frame forL(2)(R-d). In particular, this leads to a sufficient condition for a wave packet system to form a frame. On the other hand, we show...

  15. Comparing Hypertext Reading in L1 and L2: The Case of Filipino Adults (United States)

    Gruspe, Michael Angelo M.; Marinas, Christian Joshua L.; Villasin, Marren Nicole F.; Villanueva, Ariel Josephe Therese R.; Vizconde, Camilla J.


    This research probed into the reading experiences of adult readers in their first language (L1) and second language (L2). Qualitative in nature, the investigation focused on twelve (12) adult readers , six (6) males and six (6) females, whose first language is Filipino. Data were gathered through interviews and focus-group discussions. Based on…

  16. Responding to Research Challenges Related to Studying L2 Collocational Use in Professional Academic Discourse

    DEFF Research Database (Denmark)

    Henriksen, Birgit; Westbrook, Pete


    and classifying collocations used by L2 speakers in advanced, domain-specific oral academic discourse. The main findings seem to suggest that to map an informant’s complete collocational use and to get an understanding of disciplinary differences, we need to not only take account of general, academic and domain...

  17. Note-Taking Quality and Performance on an L2 Academic Listening Test (United States)

    Song, Min-Young


    This study investigated the relationships among the quality of L2 test takers' notes evaluated in terms of different levels of information and test takers' performance on open-ended listening tasks tapping into different comprehension subskills. In addition, this study examined the invariance of the structural relationships among the variables…

  18. L1 influence in the L2 acquisition of isiXhosa verb placement by ...

    African Journals Online (AJOL)

    1. Introduction. In second language (L2) acquisition research conducted within ..... versus Afrikaans-speaking beginner learners of isiXhosa, with regard to verb ..... Language contact within one home is also illustrated by the case of the four L1 ...

  19. Pragmatic assessment of schizophrenic bilinguals' L1 and L2 use ...

    African Journals Online (AJOL)

    This paper reports on a study investigating the pragmatic skills and deficits of schizophrenic bilinguals in their spontaneous first language (L1) and second language (L2) speech. Smit (2009) (see also Smit et al., this volume) argues that the locus of deficits in schizophrenic speech is semantics and suggests that a next step ...


    NARCIS (Netherlands)


    In the anaerobic fungus Neocallimastix. sp. L2 fermentation of glucose proceeds via the Embden-Meyerhof-Parnas pathway. Enzyme activities leading to the formation of succinate, lactate, ethanol, and formate are associated with the cytoplasmic fraction. The enzymes 'malic enzyme', NAD(P)H:ferredoxin

  1. Technetium(I) complexes Tc(CO)3BrL2 (L = phosphine, pyridine, isocyanide)

    International Nuclear Information System (INIS)

    Lorenz, B.; Findeisen, M.; Olk, B.; Schmidt, K.


    Technetium pentacarbonyl bromide reacts with π-acceptor ligands L (L = phosphine, pyridine, isocyanide) to form disubstituted compounds of the type Tc(CO) 3 BrL 2 . The stereochemistry of the complexes was established by infrared and 1 H-NMR measurement. Chemical shifts and the half-widths of the 99 Tc-NMR signals are discussed. (author)

  2. The Transformative Potential of Action Research and ICT in the Second Language (L2) Classroom (United States)

    Farren, Margaret; Crotty, Yvonne; Kilboy, Laura


    This study shows the transformative potential of action research and information and communications technology (ICT) in the second language (L2) classroom. Two enquiries from teacher-researchers are detailed in the article. Their engagement in a collaborative professional development Masters programme was pivotal in designing and implementing ICT…

  3. Working memory capacity and L2 speech production in a picture description task with repetition

    Directory of Open Access Journals (Sweden)

    Kyria Finardi


    Full Text Available O estudo investiga a relação entre a capacidade de memória de trabalho e os ganhos na produção oral em L2 durante uma tarefa de descrição de figura com repetição. Partindo de Fortkamp (2000 que encontrou correlações entre a capacidade de memória de trabalho e medidas de produção oral em L2 e Bygate (2001b que mostrou que na repetição de tarefas os participantes ganham em complexidade de fala em detrimento, principalmente da acurácia e da fluência, este estudo propõe que pode haver correlações entre os ganhos na complexidade da fala em L2 e a capacidade de memória de trabalho. Resultados do experimento mostram ganhos na complexidade da fala em L2, mas os mesmos não correlacionam com a capacidade de memória de trabalho. A falta de correlações é explicada em razão do pequeno número de participantes que não permitiu variação na capacidade de memória de trabalho.

  4. Personalized versus Normal Practice of L2 Speaking on Iranian EFL Learners’ Oral Proficiency

    Directory of Open Access Journals (Sweden)

    Ayda Rahmani


    Full Text Available Personalized learning is a self-initiated, self-directed or self-prioritized pursuit which gives the learner a degree of choice about the process of learning i.e. what to learn, how to learn and when to learn. Of course personalized learning does not indicate unlimited choice; because, L2 learners will still have targets to be met. However, it provides learners with the opportunity to learn in ways that suit their individual learning styles. The L2 learner should have the opportunity to freely choose a series of activities, already predisposed by the teacher, to improve and develop L2 proficiency. This is because human beings have different ways to learn and process information; and, these different ways of learning are independent of each other. In other words, learning styles and techniques differ across individuals; thus, personalized learning provides L2 learners to freely choose the activities they enjoy the most. So it is a student-centered learning method in which the interests and the preferences of the learner is taken into account.The present study is an investigation of a personalized versus normal practice of L2 proficiency. For this purpose an OPT (Oxford Placement Test was given to a total of 80 Iranian EFL learners. Then, 40 of them who were considered as intermediate learners were selected for the purpose of the study. The participants were randomly divided into two groups i.e. an experimental group and a control group. Both groups were pretested prior to the study. Then, the experimental group received the treatment in the form of personalized learning (games-based learning, songs, music, stories, English tongue twisters and the materials that the subjects were most interested in for ten sessions while the control group received a normal practice of speaking proficiency (based on New Interchange course books. After ten sessions, both groups were post tested. Then the results of the posttests were subjects of statistical analysis


    Directory of Open Access Journals (Sweden)

    Rosaria Solarino


    Full Text Available Si può oggi affrontare il tema degli errori di italiano da una prospettiva che possa giovare contemporaneamente a docenti di italiano L1 ed L2? Noi pensiamo di sì: la ricerca glottodidattica sembra aver ormai apprestato un terreno comune alle due situazioni di apprendimento, sgombrando il campo da vecchi pregiudizi e distinzioni che appaiono ormai superate. Attraverso la contrapposizione di concetti quali “lingua parlata/lingua scritta”,  “errori di lingua / errori di linguaggio”, “apprendimento spontaneo/apprendimento guidato”, “italiano L1/italiano L2”, “errori di apprendimento/errori di interferenza, si indicano diversi criteri per la interpretazione degli errori e la loro valutazione in relazione alle cause, alle situazioni comunicative, ai contesti o allo stadio di evoluzione dell’apprendimento della lingua.     Errors in italian L1 and L2: interference and learning   Can errors in Italian be approached in a way that benefits both L1 and L2 Italian teachers? We believe so: glottodidactic research seems to have prepared a common terrain for these two learning situations, clearing the field of old prejudices and obsolete distinctions.  Through the juxtaposition of concepts like “spoken language/written language”, “language errors/speech errors”, “spontaneous learning/guided learning”, “L1 Italian/L2 Italian”, “learning errors/interference errors”, different criteria for interpreting errors and evaluating them in relation to their causes, to communicative situations, to contexts and the developmental state in learning a language are singled out.

  6. L’italiano L2 : auto-apprendimento e narratività. Materiali multimediali di italiano L2 per bambini e ragazzi.

    Directory of Open Access Journals (Sweden)

    Graziella Favaro


    Full Text Available Normal 0 14 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabella normale"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman";} Normal 0 14 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabella normale"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman";} Insegnare l'italiano come seconda lingua ai bambini e ragazzi di recente immigrazione è un percorso  delicato e complesso che  fa ormai parte  dei compiti professionali ";ordinari"; dei docenti che operano nelle classi sempre più multiculturali e plurilingui. La modalità di insegnamento/apprendimento della L2 più diffusa ed efficace è quella integrata: l'alunno non italofono è inserito nella classe comune e, parallelamente, in determinati momenti, frequenta il laboratorio  di italiano L2. Per  sostenere  questo modello integrato e accompagnare il  viaggio dentro l'italiano dei bambini e dei ragazzi neoarrivati, servono materiali didattici flessibili e ricchi di proposte, utilizzabili in maniera autonoma e in piccolo gruppo; proponibili in maniera tradizionale o anche attraverso la LIM; adatti a sviluppare competenze diverse, proprie della lingua per comunicare, dell'italiano scritto e propedeutiche all'apprendimento del curricolo comune. I due corsi di italiano L2  che vengono presentati nell'ultima parte dell'articolo rispondono a queste esigenze, in quanto a sono rivolti l'uno ai bambini e l'altro ai ragazzi stranieri neo arrivati; b si propongono  il passaggio dal livello prebasico ai livelli A1, A2 e B1 del QCERL; c si

  7. Chimeric L2-Based Virus-Like Particle (VLP Vaccines Targeting Cutaneous Human Papillomaviruses (HPV.

    Directory of Open Access Journals (Sweden)

    Bettina Huber

    Full Text Available Common cutaneous human papillomavirus (HPV types induce skin warts, whereas species beta HPV are implicated, together with UV-radiation, in the development of non-melanoma skin cancer (NMSC in immunosuppressed patients. Licensed HPV vaccines contain virus-like particles (VLP self-assembled from L1 major capsid proteins that provide type-restricted protection against mucosal HPV infections causing cervical and other ano-genital and oro-pharyngeal carcinomas and warts (condylomas, but do not target heterologous HPV. Experimental papillomavirus vaccines have been designed based on L2 minor capsid proteins that contain type-common neutralization epitopes, to broaden protection to heterologous mucosal and cutaneous HPV types. Repetitive display of the HPV16 L2 cross-neutralization epitope RG1 (amino acids (aa 17-36 on the surface of HPV16 L1 VLP has greatly enhanced immunogenicity of the L2 peptide. To more directly target cutaneous HPV, L1 fusion proteins were designed that incorporate the RG1 homolog of beta HPV17, the beta HPV5 L2 peptide aa53-72, or the common cutaneous HPV4 RG1 homolog, inserted into DE surface loops of HPV1, 5, 16 or 18 L1 VLP scaffolds. Baculovirus expressed chimeric proteins self-assembled into VLP and VLP-raised NZW rabbit immune sera were evaluated by ELISA and L1- and L2-based pseudovirion (PsV neutralizing assays, including 12 novel beta PsV types. Chimeric VLP displaying the HPV17 RG1 epitope, but not the HPV5L2 aa53-72 epitope, induced cross-neutralizing humoral immune responses to beta HPV. In vivo cross-protection was evaluated by passive serum transfer in a murine PsV challenge model. Immune sera to HPV16L1-17RG1 VLP (cross- protected against beta HPV5/20/24/38/96/16 (but not type 76, while antisera to HPV5L1-17RG1 VLP cross-protected against HPV20/24/96 only, and sera to HPV1L1-4RG1 VLP cross-protected against HPV4 challenge. In conclusion, RG1-based VLP are promising next generation vaccine candidates to target

  8. Onset age of L2 acquisition influences language network in early and late Cantonese-Mandarin bilinguals. (United States)

    Liu, Xiaojin; Tu, Liu; Wang, Junjing; Jiang, Bo; Gao, Wei; Pan, Ximin; Li, Meng; Zhong, Miao; Zhu, Zhenzhen; Niu, Meiqi; Li, Yanyan; Zhao, Ling; Chen, Xiaoxi; Liu, Chang; Lu, Zhi; Huang, Ruiwang


    Early second language (L2) experience influences the neural organization of L2 in neuro-plastic terms. Previous studies tried to reveal these plastic effects of age of second language acquisition (AoA-L2) and proficiency-level in L2 (PL-L2) on the neural basis of language processing in bilinguals. Although different activation patterns have been observed during language processing in early and late bilinguals by task-fMRI, few studies reported the effect of AoA-L2 and high PL-L2 on language network at resting state. In this study, we acquired resting-state fMRI (R-fMRI) data from 10 Cantonese (L1)-Mandarin (L2) early bilinguals (acquired L2: 3years old) and 11 late bilinguals (acquired L2: 6years old), and analyzed their topological properties of language networks after controlling the language daily exposure and usage as well as PL in L1 and L2. We found that early bilinguals had significantly a higher clustering coefficient, global and local efficiency, but significantly lower characteristic path length compared to late bilinguals. Modular analysis indicated that compared to late bilinguals, early bilinguals showed significantly stronger intra-modular functional connectivity in the semantic and phonetic modules, stronger inter-modular functional connectivity between the semantic and phonetic modules as well as between the phonetic and syntactic modules. Differences in global and local parameters may reflect different patterns of neuro-plasticity respectively for early and late bilinguals. These results suggested that different L2 experience influences topological properties of language network, even if late bilinguals achieve high PL-L2. Our findings may provide a new perspective of neural mechanisms related to early and late bilinguals. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Active Learning through Materials Development: A Project for the Advanced L2 Classroom

    Directory of Open Access Journals (Sweden)

    Katrina Daly Thompson


    Full Text Available Building on the notion of active learning, the assumption that students learn more when given opportunities to practice using their skills and to receive feedback on their performance, this article de-scribes a project undertaken in an Advanced (third-year Swahili course in which students were given the opportunity to develop L2 materials for computer-mediated peer instruction. The article exam-ines the goals, design and results of the project in light of the litera-ture on active learning and learner autonomy, and suggests how the project might be improved in order to serve as a model for other Ad-vanced L2 courses.

  10. Path covering number and L(2,1)-labeling number of graphs


    Lu, Changhong; Zhou, Qing


    A {\\it path covering} of a graph $G$ is a set of vertex disjoint paths of $G$ containing all the vertices of $G$. The {\\it path covering number} of $G$, denoted by $P(G)$, is the minimum number of paths in a path covering of $G$. An {\\sl $k$-L(2,1)-labeling} of a graph $G$ is a mapping $f$ from $V(G)$ to the set ${0,1,...,k}$ such that $|f(u)-f(v)|\\ge 2$ if $d_G(u,v)=1$ and $|f(u)-f(v)|\\ge 1$ if $d_G(u,v)=2$. The {\\sl L(2,1)-labeling number $\\lambda (G)$} of $G$ is the smallest number $k$ suc...

  11. Early child L2 acquisition: Age or input effects? Neither, or both? (United States)

    Unsworth, Sharon


    This paper explores whether there is evidence for age and/or input effects in child L2 acquisition across three different linguistic domains, namely morphosyntax, vocabulary, and syntax-semantics. More specifically, it compares data from English-speaking children whose age of onset to L2 Dutch was between one and three years with data from children whose age of onset was between four and seven years in their acquisition of verb morphology, verb placement, vocabulary, and direct object scrambling. The main findings were that there were no significant differences between the two groups in any of these areas and, with the exception of scrambling, current amount of exposure was the only factor significantly related to children's scores. The paper discusses the theoretical significance of these findings with respect to the role of input in the language acquisition process and the claim that there is a critical period ending within (early) childhood.

  12. Explicit Grammar Instruction in L2 Learners’Writing Development:Effective or Ineffective?

    Institute of Scientific and Technical Information of China (English)



      It has long been in dispute about whether explicit grammar teaching is more effective in second language learning or implicit grammar teaching is. However, there are more than one factor to take into consideration while discussing which way is better for L2 learners. This short essay aims at depicting three respects concerning grammar teaching, namely learning context, language learners’beliefs and needs, and grammar instruction. When educators and practitioners try to adopt grammar instruction either implicitly or explicitly in L2 learners’writing development, they probably need to consider the above three factors and to find out the best way to produce more effective teaching results among their students

  13. Interface strategies in monolingual and end-state L2 Spanish grammars are not that different

    Directory of Open Access Journals (Sweden)

    Maria Carmen eParafita Couto


    Full Text Available This study explores syntactic, pragmatic, and lexical influences on adherence to SV and VS orders in native and fluent L2 speakers of Spanish. A judgment task examined 20 native monolingual and 20 longstanding L2 bilingual Spanish speakers’ acceptance of SV and VS structures. Seventy-six distinct verbs were tested under a combination of syntactic and pragmatic constraints. Our findings challenge the hypothesis that internal interfaces are acquired more easily than external interfaces (Sorace, 2005, 2011; Sorace & Filiaci, 2006; White 2006. Additional findings are that (a bilinguals' judgments are less firm overall than monolinguals' (i.e., monolinguals are more likely to give extreme yes or no judgments and (b individual verbs do not necessarily behave as predicted under standard definitions of unaccusatives and unergatives. Correlations of the patterns found in the data with verb frequencies suggest that usage-based accounts of grammatical knowledge could help provide insight into speakers' knowledge of these constructs.

  14. Interface strategies in monolingual and end-state L2 Spanish grammars are not that different. (United States)

    Parafita Couto, María C; Mueller Gathercole, Virginia C; Stadthagen-González, Hans


    This study explores syntactic, pragmatic, and lexical influences on adherence to SV and VS orders in native and fluent L2 speakers of Spanish. A judgment task examined 20 native monolingual and 20 longstanding L2 bilingual Spanish speakers' acceptance of SV and VS structures. Seventy-six distinct verbs were tested under a combination of syntactic and pragmatic constraints. Our findings challenge the hypothesis that internal interfaces are acquired more easily than external interfaces (Sorace, 2005, 2011; Sorace and Filiaci, 2006; White, 2006). Additional findings are that (a) bilinguals' judgments are less firm overall than monolinguals' (i.e., monolinguals are more likely to give extreme "yes" or "no" judgments) and (b) individual verbs do not necessarily behave as predicted under standard definitions of unaccusatives and unergatives. Correlations of the patterns found in the data with verb frequencies suggest that usage-based accounts of grammatical knowledge could help provide insight into speakers' knowledge of these constructs.

  15. Neutral Pion Rejection at L2 using the CMS Endcap Preshower

    CERN Document Server

    Kyriakis, Aristotelis; Loukas, Demetrios; Mousa, Jehad; Seez, Christopher


    Applying a general Artificial Neural Network approach, we have examined the possibility of neutral pion rejection at the Level 2 Trigger stage ( L2) principally using information from the CMS Endcap Preshower. We have studied both pion/photon and pion/electron discrimination. For L2 the hope was to achieve some useful pion/electron discrimination for a high electron efficiency. For a single electron/photon efficiency of 95% the results show that no useful rejection of neutral pions against electrons/photons can be obtained using this algorithm alone, due to the presence of tracker material. If the efficiency is lowered or information from the tracker is available, the rejection can increase dramatically. This will be the case for off-line analyses.

  16. On the Relationship between Brain Laterality and Language Proficiency in L2: A Replication Study

    Directory of Open Access Journals (Sweden)

    Nima Shakouri


    Full Text Available The present paper attempted to investigate whether there is any significant relationship between participants' brain laterality and L2 proficiency level. To carry out the experiment, 30 participants administered in the present study. Fifteen of them did not have any English language learning experience and were at the start of language learning, while the rest had attended L2 learning classes for about 2 years in a popular English language center, located in Bandar-e Anzali, Iran. Finally, the researchers concluded that the activity of the right hemisphere went up by the increase in language proficiency among bilinguals. Thereupon, the result of the paper was at variance with Albert and Obler's (1978 early work on hemispheric differentiation, which indicated that bilinguals were less hemispheric dominant than monolinguals.

  17. On $L^p$ Estimates for the Time-Dependent Schrodinger Operator on $L^2$

    CERN Document Server

    Mortad, M H


    Let L denote the time-dependent Schrodinger operator in n space variables. We consider a variety of Lebesgue norms for functions u on R^{n+1}, and prove or disprove estimates for such norms of u in terms of the L^2-norms of u and Lu. The results have implications for self-adjo intness of operators of the form L+V where V is a multiplication operator. The proofs are based mainly on the Strichartz-type inequalities.

  18. The Effect of Perceptual Learning on L2 Vocabulary Learning and Retention


    BEDİR, Gülay; BEKTAŞ BEDİR, Sevgi


    It is thought that learning styles have an effecton learning foreign language. This study aims to determine effects ofperceptual learning styles on L2 vocabulary learning and retention. Learningstyle preferences were assessed in the current study through the section ofCohen et al.’s Learning Style Survey (LSS) corresponding to the perceptualmodalities and achievement tests developed by the researcher was used to assessvocabulary learning and retention. And an open-ended question is tried toan...

  19. Exploring Interactions in L2 Blogging: Metadiscourse in Philippine Investigative Journalism Blogs


    Veronico Nogales Tarrayo


    Although metadiscourse has been examined in different genres, such as academic papers, newspaper editorials, school textbooks, and the like, still relatively little attention has been given to the discourse of cyber-genres, particularly blogs or weblogs. Using Hyland’s (2005) model, this paper examined the interactive and the interactional metadiscourse in Philippine investigative journalism blogs where English is used as a second language or L2. The corpus analyzed was taken from 20 invest...

  20. Technology-Enhanced L2 Reading: The Effects of Hierarchical Phrase Segmentation


    Park, Youngmin


    Sentence processing skills contribute to successful L2 reading, and require understanding and manipulation of the order and interdependence of words within a sentence. Acknowledging that this syntactic awareness is significant but challenging in language development, a small number of researchers have explored whether modified text format increases reading abilities by raising syntactic awareness. This mixed within- and between-subjects study aims to examine whether phrase-segmented format, s...

  1. Magnetic properties of S=l/2 antiferromagnetic XXZ model on the Shastry-Sutherland lattices

    International Nuclear Information System (INIS)

    Suzuki, Takafumi; Tomita, Yusuke; Kawashima, Naoki


    We study magnetic properties of the S=l/2 Ising-like XXZ model on the Shastry-Sutherland lattices considering the effect of long range interactions. By performing quantum Monte Carlo simulations, we find that magnetization plateau phases appear at one-half and one-third of the saturation magnetization. We also study the finite temperature transition to the magnetic plateau phases and discuss the universality class of the transition.

  2. Cognitive aspects of problem solving using dictionaries in L2 writing

    Directory of Open Access Journals (Sweden)

    Inna Kozlova


    Full Text Available This article reports on the use of dictionaries for L2 text production purposes by first-year ESP students. Research into dictionary use and cognitive studies of L2 writing are combined in this paper to outline the cognitive dimension of a dictionary consultation. Our objective is to focus on the situation in which an information need occurs, with a freshman ESP student as a specific user in mind. In an attempt to guarantee the relevance of consulting a dictionary, for the purposes of our study we separated the draft stage of a composition from that of its revision. In the latter stage, external resources like dictionaries were made available. Our data suggest that our students were able to detect problems in their writing and reported having improved their compositions after having had the chance to consult dictionaries. The corrections were nonetheless implemented only in one-third of all the problems detected. It was also found that the tentative solution in L2 allowed for monolingual dictionary consultation but students often opted for generating another access key in their native language.

  3. Lexical knowledge of Serbian L1 English L2 learners: Reception vs. production

    Directory of Open Access Journals (Sweden)

    Danilović-Jeremić Jelena


    Full Text Available The acquisition of lexical knowledge in a second/foreign language is often investigated by means of vocabulary size tests which assess two aspects of the learners' competence: reception and production. Estimates of these two dimensions, as well as the (potential gap between them, have important pedagogical implications in that they indicate the degree to which the learners can comprehend or use the language autonomously. Therefore, the aim of this paper is to explore the vocabulary size of three generations of B2-level L2 learners (CEFR, first-year students majoring in English at the Faculty of Philology and Arts in Kragujevac, Serbia, by means of Vocabulary Levels Tests (Laufer & Nation, 1999; Nation, 1990. The results of the statistical analyses show that the receptive vocabulary of Serbian L2 learners is much more developed than their productive vocabulary, and that the gap between lexical production and reception changes depending on the frequency of the lexemes and the proficiency level of L2 learners. The findings imply that, at the primary and secondary level of education, more attention should be paid to the development of productive lexical knowledge which is crucial not only for success in English degree courses but communication in English in general.

  4. Conduction-band valley spin splitting in single-layer H-T l2O (United States)

    Ma, Yandong; Kou, Liangzhi; Du, Aijun; Huang, Baibiao; Dai, Ying; Heine, Thomas


    Despite numerous studies, coupled spin and valley physics is currently limited to two-dimensional (2D) transition-metal dichalcogenides (TMDCs). Here, we predict an exceptional 2D valleytronic material associated with the spin-valley coupling phenomena beyond 2D TMDCs—single-layer (SL) H-T l2O . It displays large valley spin splitting (VSS), significantly larger than that of 2D TMDCs, and a finite band gap, which are both critically attractive for the integration of valleytronics and spintronics. More importantly, in sharp contrast to all the experimentally confirmed 2D valleytronic materials, where the strong valence-band VSS (0.15-0.46 eV) supports the spin-valley coupling, the VSS in SL H-T l2O is pronounced in its conduction band (0.61 eV), but negligibly small in its valence band (21 meV), thus opening a way for manipulating the coupled spin and valley physics. Moreover, SL H-T l2O possesses extremely high carrier mobility, as large as 9.8 ×103c m2V-1s-1 .

  5. A blind deconvolution method based on L1/L2 regularization prior in the gradient space (United States)

    Cai, Ying; Shi, Yu; Hua, Xia


    In the process of image restoration, the result of image restoration is very different from the real image because of the existence of noise, in order to solve the ill posed problem in image restoration, a blind deconvolution method based on L1/L2 regularization prior to gradient domain is proposed. The method presented in this paper first adds a function to the prior knowledge, which is the ratio of the L1 norm to the L2 norm, and takes the function as the penalty term in the high frequency domain of the image. Then, the function is iteratively updated, and the iterative shrinkage threshold algorithm is applied to solve the high frequency image. In this paper, it is considered that the information in the gradient domain is better for the estimation of blur kernel, so the blur kernel is estimated in the gradient domain. This problem can be quickly implemented in the frequency domain by fast Fast Fourier Transform. In addition, in order to improve the effectiveness of the algorithm, we have added a multi-scale iterative optimization method. This paper proposes the blind deconvolution method based on L1/L2 regularization priors in the gradient space can obtain the unique and stable solution in the process of image restoration, which not only keeps the edges and details of the image, but also ensures the accuracy of the results.

  6. Neural overlap of L1 and L2 semantic representations in speech: A decoding approach. (United States)

    Van de Putte, Eowyn; De Baene, Wouter; Brass, Marcel; Duyck, Wouter


    Although research has now converged towards a consensus that both languages of a bilingual are represented in at least partly shared systems for language comprehension, it remains unclear whether both languages are represented in the same neural populations for production. We investigated the neural overlap between L1 and L2 semantic representations of translation equivalents using a production task in which the participants had to name pictures in L1 and L2. Using a decoding approach, we tested whether brain activity during the production of individual nouns in one language allowed predicting the production of the same concepts in the other language. Because both languages only share the underlying semantic representation (sensory and lexical overlap was maximally avoided), this would offer very strong evidence for neural overlap in semantic representations of bilinguals. Based on the brain activation for the individual concepts in one language in the bilateral occipito-temporal cortex and the inferior and the middle temporal gyrus, we could accurately predict the equivalent individual concepts in the other language. This indicates that these regions share semantic representations across L1 and L2 word production. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. L2 Word Recognition: Influence of L1 Orthography on Multi-syllabic Word Recognition. (United States)

    Hamada, Megumi


    L2 reading research suggests that L1 orthographic experience influences L2 word recognition. Nevertheless, the findings on multi-syllabic words in English are still limited despite the fact that a vast majority of words are multi-syllabic. The study investigated whether L1 orthography influences the recognition of multi-syllabic words, focusing on the position of an embedded word. The participants were Arabic ESL learners, Chinese ESL learners, and native speakers of English. The task was a word search task, in which the participants identified a target word embedded in a pseudoword at the initial, middle, or final position. The search accuracy and speed indicated that all groups showed a strong preference for the initial position. The accuracy data further indicated group differences. The Arabic group showed higher accuracy in the final than middle, while the Chinese group showed the opposite and the native speakers showed no difference between the two positions. The findings suggest that L2 multi-syllabic word recognition involves unique processes.

  8. Through analysis of LOFT L2-3 by THYDE-P code

    International Nuclear Information System (INIS)

    Hirano, Masashi


    A through calculation of Experiment L2-3 of the Loss-of-Fluid Test (LOFT) Facility Power Ascension Series (Experiment Series L2) was performed with the THYDE-P code. The specific objectives of Experiment L2-3 were to determine the thermal-hydraulic behavior of the nuclear core and the thermal-mechanical response of the fuel rod cladding with a maximum linear heat generation rate of 39.4 kW/m. The THYDE-P code is a computer code to analyze both the blowdown and refill-reflood phases of loss-of-coolant accidents (LOCAs) of pressurized water reactors (PWRs) without a change in the methods and the models and is now under verification study and modification. The present calculation was performed by best estimate (BE) options as Sample Calculation Run 40, which is a portion of a series of THYDE-P sample calculations. The calculation was carried out from test initiation until complete submersion of the core volume with subcooled water, i.e. about 60 sec. The trend of the calculated cladding surface temperature was in good agreement with that of the experimental results. (author)

  9. [Lymphogranuloma venereum: new serovariant L2b and old "groove sign"]. (United States)

    de Lavaissière, M; Nougué, J


    An ongoing lymphogranuloma venereum (LGV) outbreak has been reported in several European countries since 2003, related to a new variant L2b. This serovar appears to affect men who have sex with men (MSM), most of them being co-infected with the Human Immunodeficiency Virus (HIV). The secondary stage of LGV may involve lymph nodes and the inguinal form has sometimes been described on each side of the inguinal ligament thus named the "groove sign". We report the case of LGV serovariant L2b acquired by an heterosexual intercourse in an HIV seronegative patient who presented with an inguinal lymph node and a "groove sign". This is an uncommon but suggestive sign of LGV and we suggest that the clinical presentation of L2b LGV might not be so different than other variants and than the 20th century authors' description. Such a new Chlamydia trachomatis variant may circulate in other populations than MSM in Europe and clinical awareness must prevail.

  10. Measuring the Effectiveness of Writing Center Consultations on L2 Writers’ Essay Writing Skills

    Directory of Open Access Journals (Sweden)

    Shanthi Tiruchittampalam


    Full Text Available With the international growth of English-medium education, tertiary institutions are increasingly providing academic support services to L2 students, and thus, the number of writing centers working with L2 student writers has also increased. Writing center practices originated in L1 English educational contexts and their appropriateness for L2 English writers requires examination. This study investigated the effect of writing center consultations on the essay writing skills of L1 Arabic foundation level students at an English-medium university in the Gulf region. Analysis was based on quantitative measures of writing ability of two distinct groups of students: an experimental group who participated in tutoring sessions at the university’s writing center and a control group who did not. Findings indicated that students who participated in writing center consultations scored significantly higher in overall essay writing scores, as well as in two aspects of writing: task fulfilment (that is ideas and text organization/coherence. These findings contribute to a limited bank of similar empirical studies on effectiveness of writing center sessions on students’ essay writing ability. They also support the case for the expansion of writing center work beyond the domains of predominantly L1 English academic communities.

  11. TCF7L2 Genetic Variants Contribute to Phenotypic Heterogeneity of Type 1 Diabetes. (United States)

    Redondo, Maria J; Geyer, Susan; Steck, Andrea K; Sosenko, Jay; Anderson, Mark; Antinozzi, Peter; Michels, Aaron; Wentworth, John; Xu, Ping; Pugliese, Alberto


    The phenotypic diversity of type 1 diabetes suggests heterogeneous etiopathogenesis. We investigated the relationship of type 2 diabetes-associated transcription factor 7 like 2 ( TCF7L2 ) single nucleotide polymorphisms (SNPs) with immunologic and metabolic characteristics at type 1 diabetes diagnosis. We studied TrialNet participants with newly diagnosed autoimmune type 1 diabetes with available TCF7L2 rs4506565 and rs7901695 SNP data ( n = 810; median age 13.6 years; range 3.3-58.6). We modeled the influence of carrying a TCF7L2 variant (i.e., having 1 or 2 minor alleles) on the number of islet autoantibodies and oral glucose tolerance test (OGTT)-stimulated C-peptide and glucose measures at diabetes diagnosis. All analyses were adjusted for known confounders. The rs4506565 variant was a significant independent factor of expressing a single autoantibody, instead of multiple autoantibodies, at diagnosis (odds ratio [OR] 1.66 [95% CI 1.07, 2.57], P = 0.024). Interaction analysis demonstrated that this association was only significant in participants ≥12 years old ( n = 504; OR 2.12 [1.29, 3.47], P = 0.003) but not younger ones ( n = 306, P = 0.73). The rs4506565 variant was independently associated with higher C-peptide area under the curve (AUC) ( P = 0.008) and lower mean glucose AUC ( P = 0.0127). The results were similar for the rs7901695 SNP. In this cohort of individuals with new-onset type 1 diabetes, type 2 diabetes-linked TCF7L2 variants were associated with single autoantibody (among those ≥12 years old), higher C-peptide AUC, and lower glucose AUC levels during an OGTT. Thus, carriers of the TCF7L2 variant had a milder immunologic and metabolic phenotype at type 1 diabetes diagnosis, which could be partly driven by type 2 diabetes-like pathogenic mechanisms. © 2017 by the American Diabetes Association.


    Directory of Open Access Journals (Sweden)

    Lidia Calabrò


    Full Text Available Lavorare sugli aspetti fonetico-fonologici di una lingua straniera risulta quanto mai importante e fondamentale, soprattutto se la L1 degli apprendenti la L2/LS è molto distante. Attraverso un’esperienza iniziata con studenti sinofoni del progetto Marco Polo / Turandot, le attività inserite nel workshop di fonetica nell’italiano L2 si presentano come proposta di didattica integrativa al fine di sensibilizzare gli studenti ai tratti soprasegmentali della L2 a contrasto con quelli della loro L1. Nel presente contributo verranno presentate alcune attività riguardanti la percezione e la realizzazione della durata vocalica e della sillaba accentata attraverso attività collaborative e il movimento del corpo. Tutte le attività prevedono un coinvolgimento personale e totale del singolo apprendente e di tutta la classe in quanto il workshop si avvale di multimodalità, multimedialità e apprendimento collaborativo al fine di scoprire i suoni della L2 e riflettere sulla loro percezione e produzione. Italian L2/LS phonetic workshops: word accent and syllable duration Working on phonetics and the phonolgical aspects language is considered important and fundamental, above all if a learner’s L1 is distant from the SL. The activities described in the paper took place during a phonetic workshop in Italian as a second language with Chinese students enrolled in the Marco Polo/Turandot project. They can be considered a teaching technique aimed at raising student awareness about the SL supra-segmental aspects in contrast to their L1. Some activities related to vowel length and stress will be presented: perception and production, cooperative learning and body movement aimed at discovering and practicing vowel length in stressed syllables (phonic stress. The activities involved the students in a more personal, total and physical collaboration together with their classmates. The multimedia workshop was designed to be multimodal and cooperative, in order to

  13. Interaction between TCF7L2 polymorphism and dietary fat intake on high density lipoprotein cholesterol.

    Directory of Open Access Journals (Sweden)

    Dhanasekaran Bodhini

    Full Text Available Recent evidence suggests that lifestyle factors influence the association between the Melanocortin 4 receptor (MC4R and Transcription Factor 7-Like 2 (TCF7L2 gene variants and cardio-metabolic traits in several populations; however, the available research is limited among the Asian Indian population. Hence, the present study examined whether the association between the MC4R single nucleotide polymorphism (SNP (rs17782313 and two SNPs of the TCF7L2 gene (rs12255372 and rs7903146 and cardio-metabolic traits is modified by dietary factors and physical activity. This cross sectional study included a random sample of normal glucose tolerant (NGT (n = 821 and participants with type 2 diabetes (T2D (n = 861 recruited from the urban part of the Chennai Urban Rural Epidemiology Study (CURES. A validated food frequency questionnaire (FFQ was used for dietary assessment and self-reported physical activity measures were collected. The threshold for significance was set at P = 0.00023 based on Bonferroni correction for multiple testing [(0.05/210 (3 SNPs x 14 outcomes x 5 lifestyle factors]. After Bonferroni correction, there was a significant interaction between the TCF7L2 rs12255372 SNP and fat intake (g/day (Pinteraction = 0.0001 on high-density lipoprotein cholesterol (HDL-C, where the 'T' allele carriers in the lowest tertile of total fat intake had higher HDL-C (P = 0.008 and those in the highest tertile (P = 0.017 had lower HDL-C compared to the GG homozygotes. In a secondary analysis of SNPs with the subtypes of fat, there was also a significant interaction between the SNP rs12255372 and polyunsaturated fatty acids (PUFA, g/day (Pinteraction<0.0001 on HDL-C, where the minor allele carriers had higher HDL-C in the lowest PUFA tertile (P = 0.024 and those in the highest PUFA tertile had lower HDL-C (P = 0.028 than GG homozygotes. In addition, a significant interaction was also seen between TCF7L2 SNP rs12255372 and fibre intake (g/day on HDL

  14. Introduction to Violent Sun-Earth Connection Events of October-November 2003 (United States)


    of i with the largest energy extractable from the huge associ- Novemberactions whonsiderimpothe omnic ated active regions. A plot summarizing solar...Geotail/EPIC and Los Alamos, NM 87545, USA. 6 of 6 Form Approved REPORT DOCUMENTATION PAGE "OMB No. 0704-0188 Public reporting burden for this...ES) 10. SPONSORIMONITOR’S ACRONYM(S) AFRL/VSBXS 11. SPONSORIMONITOR’S REPORT NUMBER(S) 12. DISTRIBUTION I AVAILABILITY STATEMENT Approved for Public

  15. Targeting Ballistic Lunar Capture Trajectories Using Periodic Orbits in the Sun-Earth CRTBP (United States)

    Cooley, D.S.; Griesemer, Paul Ricord; Ocampo, Cesar


    A particular periodic orbit in the Earth-Sun circular restricted three body problem is shown to have the characteristics needed for a ballistic lunar capture transfer. An injection from a circular parking orbit into the periodic orbit serves as an initial guess for a targeting algorithm. By targeting appropriate parameters incrementally in increasingly complicated force models and using precise derivatives calculated from the state transition matrix, a reliable algorithm is produced. Ballistic lunar capture trajectories in restricted four body systems are shown to be able to be produced in a systematic way.

  16. Sun, the Earth, and Near-Earth Space: A Guide to the Sun-Earth System (United States)

    Eddy, John A.


    In a world of warmth and light and living things we soon forget that we are surrounded by a vast universe that is cold and dark and deadly dangerous, just beyond our door. On a starry night, when we look out into the darkness that lies around us, the view can be misleading in yet another way: for the brightness and sheer number of stars, and their chance groupings into familiar constellations, make them seem much nearer to each other, and to us, that in truth they are. And every one of them--each twinkling, like a diamond in the sky--is a white-hot sun, much like our own. The nearest stars in our own galaxy--the Milky Way-- are more than a million times further away from us than our star, the Sun. We could make a telephone call to the Moon and expect to wait but a few seconds between pieces of a conversation, or but a few hours in calling any planet in our solar system.

  17. A knowledge discovery approach to explore some Sun/Earth's climate relationships (United States)

    Pou, A.; Valdes, J.


    Recent developments in data driven modeling and analysis including computational intelligence techniques may throw new light on the exploration of possible solar activity/Earth's climate relationships. Here we present three different examples of methodologies under development and some preliminary results. a) Multivariate Time Series Model Mining (MVTSMM) analysis [1] and Genetic Programming were applied to Greenland's CRETE Site-E ice core Delta O18/16 values (1721-1983, one year interval sampling) and with sunspots activity (International Sunspots Number) during the same time span [2]. According to the results (1771 to 1933 period) indicated by the lag importance spectrum obtained with MVTSMM analysis, the sun's activity itself shows high internal variability and is inhomogeneous. The Dalton minimum, a low activity period usually considered to occur between 1790 and 1830, is shown to be a complex structure beginning about 1778 and ending in 1840. Apparently, the system entered a new state in 1912. In the joint analysis, the analytical tool uses extensively the solar activity data to explain the Delta O18/16 data, showing areas of stable patterns, lag drifts and abrupt pattern disruptions, indicating changes of state in the solar processes of several kinds at different times. b) A similar MVTSMM analysis was conducted on Central England Temperature (CET) and solar activity data using Group Sunspots Number (GSN) with a useful interpretive span of time from 1771 to 1916. The joint analysis involved large amounts of solar activity variables, except for the 1843-1862 and 1877-1889 periods where the discovered models used much less information from GSN data. As with the Crete-E/ISN analysis the lag importance spectrum of CET/GSN shows a number of clear discontinuities. A quarter of them are present in both (1778-1779, 1806, 1860-1862, 1912-1913). These experiments were designed for testing methodologies and not for specific hypothesis testing. However, it seems that Delta O18/16 data would more readily respond to solar influences. This raises the suspicion that perhaps they do not only reflect temperatures but also solar activity, as well as other possible factors not directly related to atmospheric temperatures. These methodologies may be useful as exploratory tools, directing the attention to specific areas where further research should be required. This could be the case of the Delta O18/16 data, frequently considered to be a reliable and accurate proxy of temperatures. c) Another experiment was made using daily maximum temperatures from 10 Spanish meteorological stations for the period 1901-2005 [3]. Using a hybrid procedure (Differential Evolution and Fletcher-Reeves Classical Optimization) it was found that a subset was capable of preserving the 10-dimensional similarity when nonlinearly mapped into 1D. A daily index, F1 was applied to the whole dataset and grouped by years and transformed into a Kolmogorov-Smirnov dissimilarity matrix, space optimized and clustered giving the following landmarks: 1911-12, 1919-1920, 1960, 1973 and 1989. A visual comparison with the aa geomagnetic index may suggest a certain coupling with changes in the magnetic field behavior. The complexity of the patterns suggest that the possible relationships between Earth's climate and solar activity may occur in much more complex ways than just irradiance variations and simple linear correlations. REFERENCES: [1] Valdés, J.J., Bonham-Carter, G. " Time Dependent Neural Network Models For Detecting Changes of State in Complex Processes: Applications in Earth Sciences and Astronomy”. Neural Networks, vol 19, (2), pp 196-207, 2006. [2] Valdés, J., Pou, A. "Greenland Temperatures and Solar Activity: A Computational Intelligence Approach," Proceedings of the 2007 IEEE International Joint Conference on Neural Networks (IJCNN 2007). Orlando, Florida, USA. August 12-17, 2007. [3] Valdés, J., Pou, A., Orchard, B. "Characterization of Climatic Variations in Spain at the Regional Scale: A Computational Intelligence Approach," Proceedings of the IEEE World Congress on Computational Intelligence (WCCI-2008). Hong Kong, China. June 1, 2008.

  18. High-Performance Data Analysis Tools for Sun-Earth Connection Missions, Phase I (United States)

    National Aeronautics and Space Administration — The Interactive Data Language (IDL) is a standard tool used by many researchers in observational fields. Present day Sun-Earch Connection missions like RHESSI or...

  19. International Symposium on Recent Observations and Simulations of the Sun-Earth System (United States)


    of nitrates . Some “archaeological” data on SCR fluxes in the past and upper limit of total energy induced by solar flare protons are also discussed...intrinsic properties of CS equilibrium and might be used for its diagnostic. Multiscale structure of “turbulent” current sheets Laminar sheets discussed...beta plasma are favorable for self-organization to hierarchy of multiscale structures. Complex topology of magnetotail field is self-consistently

  20. 7th Class Students' Opinions on Sun, Earth and Moon System (United States)

    Aydin, Suleyman


    This study is conducted to detect the students' perceptions on Sun, Moon and Earth (SME) system and define the 7th grade students' attitudes on the subject. In the study, since it was aimed to detect and evaluate the students' perceptions on some basic astronomical concepts without changing the natural conditions, a descriptive approach was…

  1. Characterization of the FoxL2 proximal promoter and coding sequence from the common snapping turtle (Chelydra serpentina). (United States)

    Guo, Lei; Rhen, Turk


    Sex is determined by temperature during embryogenesis in snapping turtles, Chelydra serpentina. Previous studies in this species show that dihydrotestosterone (DHT) induces ovarian development at temperatures that normally produce males or mixed sex ratios. The feminizing effect of DHT is associated with increased expression of FoxL2, suggesting that androgens regulate transcription of FoxL2. To test this hypothesis, we cloned the proximal promoter (1.6kb) and coding sequence for snapping turtle FoxL2 (tFoxL2) in frame with mCherry to produce a fluorescent reporter. The tFoxL2-mCherry fusion plasmid or mCherry control plasmid were stably transfected into mouse KK1 granulosa cells. These cells were then treated with 0, 1, 10, or 100nM DHT to assess androgen effects on tFoxL2-mCherry expression. In contrast to the main hypothesis, DHT did not alter expression of the tFoxL2-mCherry reporter. However, normal serum increased expression of tFoxL2-mCherry when compared to charcoal-stripped serum, indicating that the cloned region of tFoxL2 contains cis regulatory elements. We also used the tFoxL2-mCherry plasmid as an expression vector to test the hypothesis that DHT and tFoxL2 interact to regulate expression of endogenous genes in granulosa cells. While tFoxL2-mCherry and DHT had independent effects on mouse FoxL2, FshR, GnRHR, and StAR expression, tFoxL2-mCherry potentiated low concentration DHT effects on mouse aromatase expression. Further studies will be required to determine whether synergistic regulation of aromatase by DHT and FoxL2 also occurs in turtle gonads during the sex-determining period, which would explain the feminizing effect of DHT in this species. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. The L2b real-time PCR targeting the pmpH gene of Chlamydia trachomatis used for the diagnosis of lymphogranuloma venereum is not specific to L2b strains. (United States)

    Touati, A; Peuchant, O; Hénin, N; Bébéar, C; de Barbeyrac, B


    The French Reference Centre for chlamydiae uses two real-time PCRs targeting the pmpH gene of Chlamydia trachomatis to differentiate between L strains and variant L2b, responsible for a lymphogranuloma venereum outbreak in Europe. We compared the results obtained for 122 L2b C. trachomatis-positive specimens, using the two real-time PCRs, with the sequencing of the ompA gene. Only 91 specimens were confirmed as L2b. Our results demonstrate that the lymphogranuloma venereum outbreak is no longer dominated by the variant L2b, and that many L-positive specimens were misidentified as L2b with the method used, which raises the question of its specificity. Copyright © 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  3. L’apprendimento della lingua della medicina in L2: due manuali a confronto

    Directory of Open Access Journals (Sweden)

    Maria Polita


    Full Text Available Insegnare la lingua speciale della medicina ad una classe di apprendenti L2 implica considerare diverse problematiche relative alle peculiarità del codice settoriale (variazioni diafasiche, particolarità del lessico, tecnicismi collaterali, ma anche relative al pubblico di apprendenti non italofono (tipologia, interessi, livello di apprendimento. Il panorama editoriale italiano offre pochi strumenti dedicati: tra questi Donatella Troncarelli, Dica 33. Il linguaggio della medicina, Bonacci, 1994 e Daniela Forapani, Italiano per medici, Alma edizioni, 2004. Questo studio intende mettere a confronto i due testi sottolineandone le caratteristiche e l’impostazione glottodidattica ed evidenziando come il contenuto linguistico sia proposto, quali siano le abilità favorite, quali gli obiettivi di apprendimento e quali gli strumenti forniti. Particolare attenzione viene prestata al lessico registrato nei glossari dei volumi.  Learning the language of medicine in l2: a comparison of two textbooks Teaching the special language of medicine to a class of L2 learners implies considering various issues related to the peculiarities of the sector-specific jargon (diphasic variations, peculiarities of vocabulary, collateral technicalities, also related to non-Italian-speaking learners (type, interests, level of learning. Italian publishers offer few dedicated tools: these include Donatella Troncarelli, Dica 33.Il linguaggio della medicina, Bonacci, 1994 and Daniela Forapani, Italiano per medici, Alma editions, 2004. This study aims to compare the two texts, highlighting their features and language teaching setting, showing how linguistic content is proposed, which skills are promoted, what the learning objectives are and what tools are provided. Particular attention is paid to the vocabulary in the glossaries.

  4. Application of Aura OMI L2G Products Compared with NASA MERRA-2 Assimilation (United States)

    Zeng, Jian; Shen, Suhung; Wei, Jennifer; Johnson, James E.; Su, Jian; Meyer, David J.


    The Ozone Monitoring Instrument (OMI) is one of the instruments aboard NASA's Aura satellite. It measures ozone total column and vertical profile, aerosols, clouds, and trace gases including NO2, SO2, HCHO, BrO, and OClO using absorption in the ultraviolet electromagnetic spectrum (280 - 400 nm). OMI Level-2G (L2G) products are based on the pixel-level OMI granule satellite measurements stored within global 0.25 deg. X 0.25 deg. grids, therefore they conserve all the Level 2 (L2) spatial and temporal details for 24 hours of scientific data in one file. The second Modern-Era Retrospective analysis for Research and Applications (MERRA-2) is NASA's atmospheric reanalysis, using an upgraded version of Goddard Earth Observing System Model, version 5 (GEOS-5) data assimilation system. MERRA-2 includes aerosol data reanalysis and improved representations of stratospheric ozone, compared with its predecessor MERRA, in both instantaneous and time-averaged collections. It is found that simply comparing satellite Level-3 products might cause biases, due to lack of detailed temporal and original retrieval information. It is therefore preferable to inter-compare or implement satellite derived physical quantities directly with/to model assimilation with as high temporal and spatial resolutions as possible. This study will demonstrate utilization of OMI L2G daily aerosol and ozone products by comparing them with MERRA-2 hourly aerosol/ozone simulations, matched in both space and time aspects. Both OMI and MERRA-2 products are accessible online through NASA Goddard Earth Sciences Data Information Services Center (GES DISC,

  5. Investigating the Efficacy of an Intensive English Program and the L2 Learners’ Learning Styles

    Directory of Open Access Journals (Sweden)

    Rebecca Lee Su Ping


    Full Text Available Past research has found that many pre-university L2 learners, having completed an Intensive English Program (IEP still have difficulty in undertaking various disciplines in English-speaking tertiary institutions and continue to exhibit numerous linguistic problems (Bialystok, 2001, Celce Murcia 2001. The purpose of this paper is to present the findings on the investigation of L2 learners’ English proficiency in reading, writing, grammar, listening and speaking upon their completion of an Intensive English (IE program using their IELTS (Academic, in-house exams and English Placement Tests (EPT scores, and the efficacy of IE program.  IELTS test is chosen for this study due to its increasing popularity in Malaysia and its internationally recognised value and quality.  The study was conducted in two parts. In Part One, all 72 Level 4 IE students were given an in-house EPT (English Placement Test pre-test on their entry and another EPT post-test on their exit, and then their pre-test and post-test results were compared.  In Part Two, 22 volunteers sat the IELTS test at the end of the program. The IELTS results of the 22 volunteers were compared with those who did not.  Data were analyzed using both quantitative and qualitative methods. This paper hopes to shed some light on (i whether or not L2 learners’ English language proficiency can be significantly enhanced and influenced by an intensive English program and (ii how leaners’ perception of their own learning strategies influence their learning progress.


    Directory of Open Access Journals (Sweden)

    Diego Santalucia


    Full Text Available L’articolo, prendendo spunto da recenti progetti che spingono per un utilizzo sempre più esteso di tablet e strumenti digitali in classe, fa riferimento alla Raccomandazione del Parlamento Europeo e del Consiglio dell’Unione Europea (2006 per discutere alcuni degli elementi rappresentativi della “competenza digitale” che la Raccomandazione delinea. Alla luce di questi elementi si sviluppano alcune indicazioni sull’uso ragionato dei motori di ricerca e di alcune risorse offerte dalla rete, come Google Docs e Google Drive.Seguono una breve illustrazione di Edmodo, una piattaforma didattica social, e alcune indicazioni sull’utilizzo degli smartphone per l’accesso a risorse utili e semplici da condividere in classe. Sono tracciate alcune linee guida sulla gestione di risorse già accessibili in rete e che sono, quindi, a disposizione di quegli insegnanti di Italiano L2/LS che vogliano utilizzare sistemi di condivisione online a sostegno della didattica in presenza.Digital competence and digital language teaching for Italian L2/FL teachersThe article, inspired by recent projects that push for an ever-wider use of tablets and digital tools in the classroom, refers to the Recommendation of the European Parliament and of the Council of the European Union (2006 discusses some of the representative elements of “digital competence” that the Recommendation outlines. In light of these elements, some guidelines on the use of search engines and some resources offered by the network, such as Google Docs and Google Drive, are offered.This is followed by a brief description of Edmodo, a social learning platform, and information on the use of smartphones to access helpful resources that are easy to share in class. Finally, some guidelines on the management of resources already available on the Internet for Italian L2/FL teachers who want to use online sharing systems to support of frontal lessons are given.

  7. Development of nanostructured SUS316L-2%TiC with superior tensile properties

    International Nuclear Information System (INIS)

    Sakamoto, T.; Kurishita, H.; Matsuo, S.; Arakawa, H.; Takahashi, S.; Tsuchida, M.; Kobayashi, S.; Nakai, K.; Terasawa, M.; Yamasaki, T.; Kawai, M.


    Structural materials used in radiation environments require radiation tolerance and sufficient mechanical properties in the controlled state. In order to offer SUS316L austenitic stainless steel with the assumed requirements, nanostructured SUS316L with TiC addition of 2% (SUS316L-2TiC) that is capable of exhibiting enhanced tensile ductility and flow strength sufficient for structural applications was fabricated by advanced powder metallurgical methods. The methods include MA (Mechanical Alloying), HIP (Hot Isostatic Pressing), GSMM (Grain boundary Sliding Microstructural Modification) for ductility enhancement, cold rolling at temperatures below M_d (the temperature where the martensite phase occurs by plastic deformation) for phase transformation from austenite to martensite and heat treatment for reverse transformation from martensite to austenite. It is shown that the developed SUS316L-2TiC exhibits ultrafine grains with sizes of 90–270 nm, accompanied by TiC precipitates with 20–50 nm in grain interior and 70–110 nm at grain boundaries, yield strengths of 1850 to 900 MPa, tensile strengths of 1920 to 1100 MPa and uniform elongations of 0.6–21%, respectively, depending on the heat treatment temperature after rolling at −196 °C. - Highlights: • Nanostructured SUS316L-2%TiC exhibiting sufficient tensile ductility and strength is developed. • The development requires an advanced powder metallurgical route. • The route includes MA, HIP, GSMM and thermo-mechanical treatments for phase transformation. • The austenite grain sizes are 90–270 nm and TiC precipitates 20–50 nm in grain interior. • The tensile strength are 1100–1920 MPa and uniform elongation 0.6–21%.

  8. Development of nanostructured SUS316L-2%TiC with superior tensile properties

    Energy Technology Data Exchange (ETDEWEB)

    Sakamoto, T., E-mail: [Department of Materials Science and Biotechnology, Ehime University, Matsuyama 790-8577 (Japan); Kurishita, H.; Matsuo, S.; Arakawa, H. [International Research Center for Nuclear Materials Science, IMR, Tohoku University, Oarai, Ibaraki 311-1313 (Japan); Takahashi, S.; Tsuchida, M. [Ehime University, Matsuyama 790-8577 (Japan); Kobayashi, S.; Nakai, K. [Department of Materials Science and Biotechnology, Ehime University, Matsuyama 790-8577 (Japan); Terasawa, M. [Laboratory of Advanced Science & Technology for Industry, University of Hyogo, 3-1-2 Koto, Kamigori-cho, Hyogo 678-1205 (Japan); Yamasaki, T. [Department of Materials Science & Chemistry, Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2201 (Japan); Kawai, M. [High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki-ken 305-0801 (Japan)


    Structural materials used in radiation environments require radiation tolerance and sufficient mechanical properties in the controlled state. In order to offer SUS316L austenitic stainless steel with the assumed requirements, nanostructured SUS316L with TiC addition of 2% (SUS316L-2TiC) that is capable of exhibiting enhanced tensile ductility and flow strength sufficient for structural applications was fabricated by advanced powder metallurgical methods. The methods include MA (Mechanical Alloying), HIP (Hot Isostatic Pressing), GSMM (Grain boundary Sliding Microstructural Modification) for ductility enhancement, cold rolling at temperatures below M{sub d} (the temperature where the martensite phase occurs by plastic deformation) for phase transformation from austenite to martensite and heat treatment for reverse transformation from martensite to austenite. It is shown that the developed SUS316L-2TiC exhibits ultrafine grains with sizes of 90–270 nm, accompanied by TiC precipitates with 20–50 nm in grain interior and 70–110 nm at grain boundaries, yield strengths of 1850 to 900 MPa, tensile strengths of 1920 to 1100 MPa and uniform elongations of 0.6–21%, respectively, depending on the heat treatment temperature after rolling at −196 °C. - Highlights: • Nanostructured SUS316L-2%TiC exhibiting sufficient tensile ductility and strength is developed. • The development requires an advanced powder metallurgical route. • The route includes MA, HIP, GSMM and thermo-mechanical treatments for phase transformation. • The austenite grain sizes are 90–270 nm and TiC precipitates 20–50 nm in grain interior. • The tensile strength are 1100–1920 MPa and uniform elongation 0.6–21%.

  9. Regularized Laplace-Fourier-Domain Full Waveform Inversion Using a Weighted l 2 Objective Function (United States)

    Jun, Hyunggu; Kwon, Jungmin; Shin, Changsoo; Zhou, Hongbo; Cogan, Mike


    Full waveform inversion (FWI) can be applied to obtain an accurate velocity model that contains important geophysical and geological information. FWI suffers from the local minimum problem when the starting model is not sufficiently close to the true model. Therefore, an accurate macroscale velocity model is essential for successful FWI, and Laplace-Fourier-domain FWI is appropriate for obtaining such a velocity model. However, conventional Laplace-Fourier-domain FWI remains an ill-posed and ill-conditioned problem, meaning that small errors in the data can result in large differences in the inverted model. This approach also suffers from certain limitations related to the logarithmic objective function. To overcome the limitations of conventional Laplace-Fourier-domain FWI, we introduce a weighted l 2 objective function, instead of the logarithmic objective function, as the data-domain objective function, and we also introduce two different model-domain regularizations: first-order Tikhonov regularization and prior model regularization. The weighting matrix for the data-domain objective function is constructed to suitably enhance the far-offset information. Tikhonov regularization smoothes the gradient, and prior model regularization allows reliable prior information to be taken into account. Two hyperparameters are obtained through trial and error and used to control the trade-off and achieve an appropriate balance between the data-domain and model-domain gradients. The application of the proposed regularizations facilitates finding a unique solution via FWI, and the weighted l 2 objective function ensures a more reasonable residual, thereby improving the stability of the gradient calculation. Numerical tests performed using the Marmousi synthetic dataset show that the use of the weighted l 2 objective function and the model-domain regularizations significantly improves the Laplace-Fourier-domain FWI. Because the Laplace-Fourier-domain FWI is improved, the

  10. Duplication and relocation of the functional DPY19L2 gene within low copy repeats

    Directory of Open Access Journals (Sweden)

    Cheung Joseph


    Full Text Available Abstract Background Low copy repeats (LCRs are thought to play an important role in recent gene evolution, especially when they facilitate gene duplications. Duplicate genes are fundamental to adaptive evolution, providing substrates for the development of new or shared gene functions. Moreover, silencing of duplicate genes can have an indirect effect on adaptive evolution by causing genomic relocation of functional genes. These changes are theorized to have been a major factor in speciation. Results Here we present a novel example showing functional gene relocation within a LCR. We characterize the genomic structure and gene content of eight related LCRs on human Chromosomes 7 and 12. Two members of a novel transmembrane gene family, DPY19L, were identified in these regions, along with six transcribed pseudogenes. One of these genes, DPY19L2, is found on Chromosome 12 and is not syntenic with its mouse orthologue. Instead, the human locus syntenic to mouse Dpy19l2 contains a pseudogene, DPY19L2P1. This indicates that the ancestral copy of this gene has been silenced, while the descendant copy has remained active. Thus, the functional copy of this gene has been relocated to a new genomic locus. We then describe the expansion and evolution of the DPY19L gene family from a single gene found in invertebrate animals. Ancient duplications have led to multiple homologues in different lineages, with three in fish, frogs and birds and four in mammals. Conclusion Our results show that the DPY19L family has expanded throughout the vertebrate lineage and has undergone recent primate-specific evolution within LCRs.

  11. Supersymmetric corrections to the K/sub L/ -> 2. gamma. process

    Energy Technology Data Exchange (ETDEWEB)

    Abad, J.; Rodriguez-Trias, R.


    An improved calculation of susy-corrections to the K/sub L/ -> 2..gamma.. process is done, including also the charged-Higgs contributions. The Higgsino-Wino mixings are carefully considered and the results are presented as a function of a susy-breaking parameter. An evaluation of the diagrams which include super-symmetric penguins is also done, finding a contribution somewhat lower than the previous one. We conclude that the Higgs and susy amplitudes are smaller than the standard amplitude.

  12. Basement membrane heparan sulfate proteoglycan from the L2 rat yolk sac carcinoma

    DEFF Research Database (Denmark)

    Fenger, M; Wewer, U; Albrechtsen, R


    Heparan sulfate proteoglycan from the L2 rat yolk sac carcinoma has been purified and partially characterized. The proteoglycan has an apparent Mr of 750 000, 35% of which represents the core protein. The core protein seems to be homogeneous, whereas the heparan sulfate chains are heterogeneous...... with an Mr of about 50 000-70 000, with 30% of the glucosamine being N-sulfated. Antibodies raised against the core protein of the heparan sulfate proteoglycan reacted with basement membranes of various rat and human tissue....

  13. T2L2 on JASON-2: First Evaluation of the Flying Model (United States)


    Para, J.-M. Torre R&D Metrology CNRS/GEMINI Observatoire de la Côte d’Azur Caussol, France E-mail: Abstract...Laser Link” experiment T2L2 [1], under development at OCA (Observatoire de la Côte d’Azur) and CNES (Centre National d’Etudes Spatiales), France, will be...Experimental Astronomy, 7, 191-207. [2] P. Fridelance and C. Veillet, 1995, “Operation and data analysis in the LASSO experiment,” Metrologia

  14. Characterization of a linear epitope on Chlamydia trachomatis serovar L2 DnaK-like protein

    DEFF Research Database (Denmark)

    Ozkokmen, D; Birkelund, Svend; Christiansen, Gunna


    A cytoplasmic 75-kDa immunogen from Chlamydia trachomatis serovar L2 has previously been characterized as being similar to the Escherichia coli heat shock protein DnaK. We have localized a linear epitope for one monoclonal antibody specific for C. trachomatis DnaK. By use of a recombinant DNA...... technique, the epitope was limited to 14 amino acids. With synthetic peptides, the epitope was further limited to eight amino acids. Six of these amino acids are conserved in bovine HSP70, which has a known three-dimensional structure. The amino acid sequence homologous to the epitope is located in a linear...

  15. Sensitivity to phonological context in L2 spelling: evidence from Russian ESL speakers

    DEFF Research Database (Denmark)

    Dich, Nadya


    The study attempts to investigate factors underlying the development of spellers’ sensitivity to phonological context in English. Native English speakers and Russian speakers of English as a second language (ESL) were tested on their ability to use information about the coda to predict the spelling...... on the information about the coda when spelling vowels in nonwords. In both native and non-native speakers, context sensitivity was predicted by English word spelling; in Russian ESL speakers this relationship was mediated by English proficiency. L1 spelling proficiency did not facilitate L2 context sensitivity...

  16. The Culture of Writing of L2 Writers in Transition from Secondary School to Postsecondary Education

    Directory of Open Access Journals (Sweden)

    Lee Lai Fong


    Full Text Available This study looks at the culture of writing of second language (L2 writers in English who are in transition from secondary school to postsecondary education. It looks at four case studies of students in their first semester of postsecondary education in a public university. It examines their negotiation of culture of writing in secondary school to the culture of writing in postsecondary education from the perspective of sociocultural theory. Data was obtained from interviews, personal narratives and observation. The findings show that sociocultural theory can offer an understanding of these ESL writers as they move from one culture of writing to another

  17. Diamagnetism of the B10H12L2 series compounds

    International Nuclear Information System (INIS)

    Volkov, V.V.; Ikorskij, V.N.; Dunaev, S.T.


    The method of static magnetic susceptibility is used to study diamagnetic susceptibilities of a number of B 10 H 12 L 2 (where L - nitrogen, sulfur, phosphorus-containing organic ligands) decaborane-derivatives and to draw the increment χ M -125 for the nido cluster (B 10 H 12 ) and boron atomic increment χ bar M -9.0 in this cluster. The absolute value χ B in (B 10 H 12 ) cluster is much higher than χ B for noncluster systems (2.7-7.6). This difference proves electron delocalization in (B 10 H 12 ) and the aromatic nature of this nido-cluster

  18. Constructing pairs of dual bandlimited frame wavelets in L^2(R^n)

    DEFF Research Database (Denmark)

    Lemvig, Jakob


    combination of dilations of ψ with explicitly given coefficients. The result allows a simple construction procedure for pairs of dual wavelet frames whose generators have compact support in the Fourier domain and desired time localization. The construction relies on a technical condition on ψ, and we exhibit......Given a real, expansive dilation matrix we prove that any bandlimited function ψ∈L2(Rn), for which the dilations of its Fourier transform form a partition of unity, generates a wavelet frame for certain translation lattices. Moreover, there exists a dual wavelet frame generated by a finite linear...

  19. Scaling of the L2,3 circular magnetic x-ray dichroism of Fe nitrides

    International Nuclear Information System (INIS)

    Alouani, M.; Wills, J.M.; Wilkins, J.W.


    We have implemented the calculation of the x-ray-absorption cross section for left- and right-circularly polarized x-ray beams within the local-density approximation by means of our all-electron full-relativistic and spin-polarized full-potential linear muffin-tin orbital method. We show that the L 2,3 circular magnetic x-ray dichroism of Fe, Fe 3 N, and Fe 4 N compounds scales to a single curve when divided by the local magnetic moment. Sum rules determine the spin and orbital magnetic moment of iron atoms in these ordered iron nitrides. copyright 1998 The American Physical Society

  20. Informational Packaging, Level of Formality, and the Use of Circumstance Adverbials in L1 and L2 Student Academic Presentations (United States)

    Zareva, Alla


    The analysis of circumstance adverbials in this paper was based on L1 and L2 corpora of student presentations, each of which consisting of approximately 30,000 words. The overall goal of the investigation was to identify specific functions L1 and L2 college students attributed to circumstance adverbials (the most frequently used adverbial class in…