Chinese secondary school teachers’ conceptions of L2 assessment: A mixed-methods study

Teacher conceptions of assessment influence their implementation of learning-focused assessment initiatives as advocated in many educational policy documents. This mixed-methods study investigated Chinese secondary school teachers’ conceptions of L2 assessment in the context of an exam-oriented educational system which emphasizes English grammar, vocabulary and reading comprehension skills. For the quantitative part of the study, survey data were collected to gauge the conceptions of assessment held by 66 senior secondary EFL teachers from six schools in Eastern China. For the qualitative part, case studies of two teachers from schools with different rankings were conducted. Quantitative results showed that the teacher participants as a group agreed most with the view that assessment is to help learning. However, there was a strong association between two factors, that is, the assessment as accurate for examination and teacher/school control factor, and the assessment as accurate for student development factor. The strong association indicated that it may be less likely for the group of teachers to adopt the formative assessment initiatives emphasizing student development as promoted in the English curriculum reform. Qualitative findings further revealed individual differences in the two case study teachers’ conceptions and practices of assessment as well as the interplay among meso-level (e.g., school factor), micro-level (e.g., student factor), and macro-level (e.g., sociocultural and policy contexts) factors in shaping the teachers’ different conceptions and practices of assessment. A situated approach has been proposed to enhance teachers’ assessment literacy

A Sub-Nanosecond Gate Bias-Switching Circuit for GaN RF Power Amplifiers

In this letter, we present a design of a fast gate-switching power amplifier (GSPA) aimed at reducing its power consumption. This GSPA features a dedicated fast gate-switching circuit that commutates the gallium nitride (GaN) transistor between a nominal gate bias voltage (GSPA ON) and a strong negative voltage (GSPA OFF), thereby generating two discrete output power levels in an RF-pulsewidth modulation (PWM) fashion. A fast gate-switching circuit, including a commercial digital voltage isolator, is designed to switch between two gate bias voltages. The gate stability resistor and transmission line (TL) are carefully placed and designed to reduce the GSPA parasitic bias line and enable fast switching. Measured results provided a rise and fall time of 750 and 950 ps, respectively, and achieved RF pulsewidths as narrow as 5.88 ns, thus corresponding to a 170-MHz bandwidth

Transverse Radial Flow Effects on Two- and Three-Particle Angular Correlations

We use a simple a transverse radial boost scenario coupled to PYTHIA events to illustrate the impact radial flow may have on two- and three-particle correlation functions measured in heavy-ion collisions. We show that modest radial velocities can impart strong modifications to the correlation functions, some of which may be interpreted as same side ridge and away side structure that can mimic conical emission.Comment: 7 figures, 9 pages, Material presented in part by Pruneau at HOC 07, Montreal, Canada Accepted for publication in Nucl Phys A (Jan 2008

Proteomic and functional analyses of the virion transmembrane proteome of cyprinid herpesvirus 3

Virion transmembrane proteins (VTPs) mediate key functions in the herpesvirus infectious cycle. Cyprinid herpesvirus 3 (CyHV-3) is the archetype of fish alloherpesviruses. The present study was devoted to CyHV-3 VTPs. Using mass spectrometry approaches, we identified 16 VTPs of the CyHV-3 FL strain. Mutagenesis experiments demonstrated that eight of these proteins are essential for viral growth in vitro (ORF32, ORF59, ORF81, ORF83, ORF99, ORF106, ORF115, and ORF131), and eight are non-essential (ORF25, ORF64, ORF65, ORF108, ORF132, ORF136, ORF148, and ORF149). Among the non-essential proteins, deletion of ORF25, ORF132, ORF136, ORF148, or ORF149 affects viral replication in vitro, and deletion of ORF25, ORF64, ORF108, ORF132, or ORF149 impacts plaque size. Lack of ORF148 or ORF25 causes attenuation in vivo to a minor or major extent, respectively. The safety and efficacy of a virus lacking ORF25 were compared to those of a previously described vaccine candidate deleted for ORF56 and ORF57 (Δ56-57). Using quantitative PCR, we demonstrated that the ORF25 deleted virus infects fish through skin infection and then spreads to internal organs as reported previously for the wild-type parental virus and the Δ56-57 virus. However, compared to the parental wild-type virus, the replication of the ORF25 deleted virus was reduced in intensity and duration to levels similar to those observed for the Δ56-57 virus. Vaccination of fish with a virus lacking ORF25 was safe but had low efficacy at the doses tested. This characterization of the virion transmembrane proteome of CyHV-3 provides a firm basis for further research on alloherpesvirus VTPs. IMPORTANCE Virion transmembrane proteins play key roles in the biology of herpesviruses. Cyprinid herpesvirus 3 (CyHV-3) is the archetype of fish alloherpesviruses and the causative agent of major economic losses in common and koi carp worldwide. In this study of the virion transmembrane proteome of CyHV-3, the major findings were: (i) the FL strain encodes 16 virion transmembrane proteins; (ii) eight of these proteins are essential for viral growth in vitro; (iii) seven of the non-essential proteins affect viral growth in vitro, and two affect virulence in vivo; and (iv) a mutant lacking ORF25 is highly attenuated but induces moderate immune protection. This study represents a major breakthrough in understanding the biology of CyHV-3 and will contribute to the development of prophylactic methods. It also provides a firm basis for the further research on alloherpesvirus virion transmembrane proteins

Microwave-optical double resonance in a erbium-doped whispering-gallery-mode resonator

We showcase an erbium-doped whispering-gallery-mode resonator with optical modes that display intrinsic quality factors better than $10^8$ (linewidths less than 2 MHz), and coupling strengths to collective erbium transitions of up to 2$\pi\times$1.2 GHz - enough to reach the ensemble strong coupling regime. Our optical cavity sits inside a microwave resonator, allowing us to probe the spin transition which is tuned by an external magnetic field. We show a modified optically detected magnetic resonance measurement that measures population transfer by a change in coupling strength rather than absorption coefficient. This modification was enabled by the strong coupling to our modes, and allows us to optically probe the spin transition detuned by more than the inhomogeneous linewidth. We contrast this measurement with electron paramagnetic resonance to experimentally show that our optical modes are confined in a region of large microwave magnetic field and we explore how such a geometry could be used for coherent microwave-optical transduction.Comment: 8 pages, 6 figure

Middle school student attitudes toward science, and their relationships with instructional practices: a survey of Chinese students’ preferred versus actual instruction

This study explored relationships between students\u27 attitudes toward science and their preferred versus actual experience of cooperative, constructivist-oriented, or direct instruction. The sample consisted of 1334 Chinese middle school students in physics and chemistry classrooms. Results showed that students report experiencing more direct instruction, very little constructivist-oriented instruction, and a moderate amount of cooperative instruction. Attitudes toward science were positively related to cooperative teaching strategies like group work in class or developing small-group projects. There was no significant effect of constructivist-oriented instruction or of direct instruction on students\u27 attitudes. Whereas previous studies demonstrated positive impacts of constructivist teaching on student understanding of science concepts, student attitude toward school science appears to be more related to social interaction or cooperation. Lack of any statistically significant differential effect from constructivist-oriented instruction might also be related to the overall low incidence of such instruction experienced by our sample

Hydrodynamics: Fluctuating Initial Conditions and Two-particle Correlations

Event-by-event hydrodynamics (or hydrodynamics with fluctuating initial conditions) has been developed in the past few years. Here we discuss how it may help to understand the various structures observed in two-particle correlations.Comment: 7 pages, 9 figures, presented at the Workshop on Saturation, the Color Glass Condensate and Glasma: What Have we Learned from RHIC