The appearance of half-quantized thermal Hall conductivity in α-RuCl_{3} in the presence of in-plane magnetic fields has been taken as a strong evidence for the Kitaev spin liquid. Apart from the ...quantization, the observed sign structure of the thermal Hall conductivity is also consistent with predictions from the exact solution of the Kitaev honeycomb model. Namely, the thermal Hall conductivity changes sign when the field direction is reversed with respect to the heat current, which is perpendicular to one of the three nearest neighbor bonds on the honeycomb lattice. On the other hand, the thermal Hall conductivity is almost zero when the field is applied along the bond direction. Here, we theoretically demonstrate that such a peculiar sign structure of the thermal Hall conductivity is a generic property of the polarized state in the presence of in-plane magnetic fields. In this case, the thermal Hall effect arises from topological magnons with finite Chern numbers, and the sign structure follows from the symmetries of the momentum space Berry curvature. Using a realistic spin model with bond-dependent interactions, we show that the thermal Hall conductivity can have a magnitude comparable to that observed in the experiments. Hence, the sign structure alone cannot make a strong case for the Kitaev spin liquid. The quantization at very low temperatures, however, will be a decisive test as the magnon contribution vanishes in the zero temperature limit.
Anti-Asian discrimination and assaults have increased significantly during the Coronavirus disease 2019 (COVID-19) pandemic, contributing to a "secondary contagion" of racism. The United States has a ...long and well-documented history of both interpersonal and structural anti-Asian discrimination, and the current pandemic reinforces longstanding negative stereotypes of this rapidly growing minority group as the "Yellow Peril."We provide a general overview of the history of anti-Asian discrimination in the United States, review theoretical and empirical associations between discrimination and health, and describe the associated public health implications of the COVID-19 pandemic, citing relevant evidence from previous disasters in US history that became racialized.Although the literature suggests that COVID-19 will likely have significant negative effects on the health of Asian Americans and other vulnerable groups, there are reasons for optimism as well. These include the emergence of mechanisms for reporting and tracking incidents of racial bias, increased awareness of racism's insidious harms and subsequent civic and political engagement by the Asian American community, and further research into resilience-promoting factors that can reduce the negative health effects of racism.
While previous research has investigated student perceptions of the benefits of self-assessment in print-based L2 writing tasks, little research has delved into students' self-assessment processes in ...technology-enhanced L2 writing tasks, which may create new opportunities and challenges for self-assessment. Drawing on multiple sources of data, including student interviews, classroom observations, and documents, this multiple case study examines how Chinese university students of differing L2 proficiency assess their own digital multimodal composing (DMC) projects. The findings revealed that L2 student writers were involved in the processes of determining performance criteria, self-directed feedback seeking, self-reflection, and taking action in their DMC self-assessment. The findings also indicated that while the high-proficiency students' self-assessment process was more cyclical, the middle- and low-proficiency students’ self-assessment processes were more linear, and they also exhibited differing features in their specific DMC self-assessment processes. This study provides insights into conceptualizing models of student self-assessment in L2 writing and adds to our understanding of how to assess student performance in technology-enhanced L2 writing tasks.
•This study examined how L2 students assess their own digital multimodal composing (DMC) performance.•A process-oriented approach was taken to examine L2 students' self-assessment processes.•Four micro-processes were identified in L2 students' self-assessment in DMC.•Students of differing language proficiency exhibited different features in their self-assessment processes.
This article introduced a teaching innovation practice, i.e., digital multimodal composing, in College English course in mainland China. The purpose of this practice is to respond to the developing ...L2 student writers' difficulty of lacking linguistic resources to express their creative ideas, and empower them to leverage multiple modes other than the language mode to make their meaning, and meanwhile to raise their interest, motivation, and enjoyment in L2 writing. Data were collected from student interviews in conjunction with DMC samples. It was reported that a majority of the developing L2 student writers positively perceived the affordances of DMC, that is, having access to multiple modes to fully express creative ideas, feeling more enjoyable and less anxious in L2 writing, being more motivated to interact with authentic audiences, and forming the habit of constantly revising scripts. This points to important pedagogical implications for the future implementation of digital multimodal composing projects by launching individual digital multimodal composing tasks, constructing and validating DMC rubrics, and enhancing collaboration between teachers and researchers to bring innovative DMC pedagogy into L2 writing instruction practice.
While a plethora of research on second language (L2) writing instruction has focused on instructional approaches, teacher feedback and assessment practice, and student learning experiences, little ...research has examined issues regarding L2 writing curriculum. In particular, L2 writing curriculum discourse, as one important window to probe into the underlying teaching philosophies and beliefs that impact profoundly on the teaching reality, has received limited attention. To address this void, the current study drew on a teaching and learning writing discourse framework to analyse 68 Chinese English as a foreign language (EFL) university writing curriculum documents. The study found that Chinese college EFL writing curricula and instruction present a relatively comprehensive view of writing and learning to write, at least at the document level. Some salient features of the Chinese EFL writing discourse distribution reflect broader Chinese social changes, such as the promotion of the English for academic purposes (EAP) approach and the dominance of the genre-oriented approach. However, some concerns remain about current Chinese EFL writing instruction, such as a lack of creativity discourse, social practice discourse, and sociopolitical discourse, as well as ill-implemented skills discourse and process discourse. Implications for writing curriculum development, instructional approach improvement, and future L2 writing research are discussed.
Objective
Microlaryngeal surgery typically requires oxygenation and ventilation via either an endotracheal tube (ETT), jet ventilation (JV), or intermittent apnea with an ETT. Transnasal Humidified ...Rapid Insufflation Ventilatory Exchange (THRIVE) delivered by high flow nasal cannula has been reported as an alternative technique. This method of apneic oxygenation and ventilation allows for stable, unobstructed visualization of immobile laryngeal structures. We aim to describe the technique and characterize intraoperative parameters related to its safety.
Study Design
Case Series.
Methods
The electronic medical record was reviewed for patients who underwent microlaryngoscopy using THRIVE technique. Patient demographics, procedural details, operative parameters, and anesthesia records were reviewed. Descriptive statistics were reported.
Results
A total of 53 patients underwent microlaryngoscopy using THRIVE as the sole method of ventilation, with 62% female. Median age was 51 years, and median BMI was 25 kg/m2. Most patients were ASA class 2, and most had a Mallampati score of 2. The most common surgical indications were subglottic stenosis, vocal fold lesions, and vocal fold paralysis. Median apnea time was 16 minutes. At the end of case, median end tidal CO2 was 50 mmHg, and median minimum SpO2 was 95. Six cases required supplementation of THRIVE with JV or tracheal intubation for sustained oxygen desaturation. There was an increase in end tidal CO2 of 0.844 mmHg/min of apneic time.
Conclusions
THRIVE is a safe and effective technique for oxygenation and ventilation in microlaryngeal, non‐laser surgery in appropriately selected patients. To ensure safety, back‐up plans such as jet ventilation and microlaryngeal ETT should be available.
Level of Evidence
4 Laryngoscope, 131:587–591, 2021
Recently, Co-based honeycomb magnets have been proposed as promising candidate materials to host the Kitaev spin liquid (KSL) state. One of the front-runners is BaCo2(AsO4)2 (BCAO), where it was ...suggested that the exchange processes between Co2+ ions via the surrounding edge-sharing oxygen octahedra could give rise to bond-dependent Kitaev interactions. In this work, we present and analyze a comprehensive inelastic neutron scattering (INS) study of BCAO with fields in the honeycomb plane. Combining the constraints from the magnon excitations in the high-field polarized state and the inelastic spin structure factor measured in zero magnetic field, we examine two leading theoretical models: the Kitaev-type JKΓΓ′ model and the XXZ-J1-J3 model. We show that the existing experimental data can be consistently accounted for by the XXZ-J1-J3 model but not by the JKΓΓ′ model, and we discuss the implications of these results for the realization of a spin liquid phase in BCAO and more generally for the realization of the Kitaev model in cobaltates.
Importantly, we found that SpCas9‐NG could target other types of PAMs, with targeting efficiencies of 3.4% for NGC, 13.0% for NGA and 5.2% for NGT on average, which were higher than these of ZmCas9 ...and xCas9 3.7 at these target sites (Figure c). ...we noticed a very high targeting efficiency of SgR‐A3 (NGA PAM) by the SpCas9‐NG variant (i.e. 48.0%), which was comparable to that of wild‐type Cas9 targeting NGG PAMs. ...our results show that SpCas9‐NG variant can induce indels at non‐NGG sites with higher efficiency than ZmCas9 or xCas9 3.7, but not as efficiently as ZmCas9 for NGG PAM in Arabidopsis. ...we demonstrated that both the xCas9 3.7 and SpCas9‐NG variants could be used to generate certain mutation types for the candidate genes in Arabidopsis as an alternative to the wild‐type Cas9, especially when the NGG PAMs in these genes are limited. ...we also found that both xCas9 3.7 and SpCas9‐NG can successfully induce homozygous/biallelic and heterozygous mutations at broad PAM targets once the plants are edited by these systems. ...we propose that these variants could be used as an alternative to wild‐type Cas9 in Arabidopsis to generate certain types of mutations for candidate genes when NGG PAMs are not available.
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