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Protest walls have played an important role in movement communication and mobilizing the public. We focus on contentious performances and the way diverse actors co-authored spaces into the protest walls that were seen in Hong Kong and other countries including Lebanon, Iraq, and Taiwan. We argue that once created, protest walls can become objects symbolic of dissent. They exist as a lexicon-a complex language of symbols and spatial practices. This language is now an internationally understood method of protest which has a high degree of transferability and can be adapted into local contentious contexts or used to transmit local concerns into the international consciousness. Finally, we show that the protest wall can shed new light on the relationship between activists, their claims and their targets that does not exist in other types of contentious performance.
This essay traces the study of the vexed topic of sentimentalism in long nineteenth-century American critical discourse. Over the past decades, scholars have drawn upon different disciplines and critical theories to reframe the expansive and subtle complexities of sentimentalism’s influence as mode and ideology; these investigations, under the capacious term “feeling,” sometimes dovetail with, and other times are disaggregated from, inquiries into sympathy, affect studies, the sensorium, and the history of emotions. Although the turn to affect has been seen as a way out of political overdetermination, concerns about liberatory potential and structural collusions were prefigured and informed by debates about sentimentality’s ethical bind. This essay turns to negative terms, glossing the use of “unfeeling” in Harriet Beecher Stowe’s Uncle Tom’s Cabin and then appearances of “unfeeling” and “unsympathetic” in illustrative scholarship over the last three decades for their operations and implications. The chapter then teases out the cultural politics of unfeeling from a queer, feminist of color perspective: What if one reconsiders unfeeling from the vantage point of those marginalized and not simply as hegemonic imposition? The discussion closes with Yankton Dakota writer Zitkala-Ša, reassessing the Indigenous activist’s wish, in her own words, to become “unfeeling stone.”
The Hele-Shaw–Cahn–Hilliard model, coupled with phase separation, is numerically simulated to demonstrate the formation of anomalous fingering patterns in a radial displacement of a partially miscible binary-fluid system. The composition of injected fluid is set to be less viscous than the displaced fluid and within the spinodal or metastable phase-separated region, in which the second derivative of the free energy is negative or positive, respectively. Because of phase separation, concentration evolves non-monotonically between the injected and displaced fluids. The simulations reveal four areas of the concentration distribution between the fluids: the inner core; the low-concentration grooves/high-concentration ridges; the isolated fluid fragments or droplets; the mixing zone. The grooves/ridges and the fragments/droplets, which are the unique features of phase separation, form in the spinodal and metastable regions. Four typical types of patterns are categorized: core separation (CS); fingering separation (FS); separation fingering (SF); lollipop fingering, in the order of the dominance of phase separation, respectively. For the patterns of CS and FS, isolated fluid fragments or droplets around the inner core are the main features. Fingering formation is better maintained with droplets in the SF pattern if the phase separation is relatively weaker than viscous fingering (VF). Even continuous fingers are well preserved in the case of dominant VF; phase separation results in lollipop-shaped fingers. The evolving trend of the patterns is in line with the experiments. These patterns are summarized in a pattern diagram, mainly by the magnitude of the second derivative of the free energy profile.
The dual route cascaded (DRC) model proposes that the mapping from orthography to phonology occurs through two pathways: the sublexical and lexical routes. Cross-linguistic studies have found that Chinese character reading relies more on the lexical pathway, whereas English word reading relies more on the sublexical pathway. However, it remains unclear how these two pathways collaborate in the L2 word reading of Chinese–English bilinguals and whether their reading strategies are influenced by L2 proficiency. In the current study, 72 Chinese–English bilinguals with varying levels of L2 proficiency were tested. They were asked to name English words that varied in frequency and spelling-sound consistency. The results showed that participants with lower L2 proficiency were more sensitive to frequency, indicating a greater reliance on lexical processing in L2 word reading. In contrast, participants with higher L2 proficiency were more sensitive to consistency, suggesting a greater reliance on sublexical processing. These findings suggest that L2 word reading strategies vary as a function of L2 proficiency. As L2 proficiency increases, Chinese–English bilinguals’ reading strategies may shift from primarily relying on lexical to sublexical processing. This study provides evidence from L2 readers for the DRC model, helping to broaden the explanatory scope of the model.
To compare the recovery of yeast from hospital surfaces from two different collection methods: Eswab moistened with molecular water, and premoistened stick-mounted sponge.
Design:
Comparison of collection methods for the recovery of yeast in the hospital environment.
Setting:
This study took place at intensive care units of a large academic medical center.
Numerical simulations are conducted to investigate particle suspension and deposition within turbidity currents. Utilizing Lagrangian particle tracking and a discrete element model, our numerical approach enables a detailed examination of autosuspension, deposition and bulk behaviours of turbidity current. We specifically focus on flow regimes where particle settling and buoyancy-induced hydrodynamics play equally important roles. Our discussion is divided into three parts. Firstly, we examine the main body of the current formed by suspended particles, revealing a temporal evolution consisting of initial slumping, propagation and dissipation stages. Our particle calculation allows for the tracking of autosuspended particles, enabling a deeper understanding of the connection between autosuspension and current propagation through energy budget analysis. In the second part, we delve into particle deposition, highlighting transverse and longitudinal variations. Transverse variations arise from lobe-and-cleft (LC) flow features, while longitudinal variations result from vortex detachment, particularly notable with large-sized particles. We observe that as particle size increases, leading to a particle Stokes number greater than 0.1, rapid particle settling suppresses the LC flow structure, resulting in wider lobes at the deposition height. Lastly, we propose a new scaling law for the propagation speed and current length. Our simulation results demonstrate close agreement with this new scaling law, providing valuable insights into turbidity current dynamics.
In this paper, we first introduce the concept of symmetric biderivation radicals and characteristic subalgebras of Lie algebras and study their properties. Based on these results, we precisely determine biderivations of some Lie algebras including finite-dimensional simple Lie algebras over arbitrary fields of characteristic not $2$ or $3$, and the Witt algebras $\mathcal {W}^+_n$ over fields of characteristic $0$. As an application, commutative post-Lie algebra structure on the aforementioned Lie algebras is shown to be trivial.
In the context of the Omicron-induced lockdown in Shanghai, this paper investigated the appeals for assistance by citizens on Weibo, aiming to understand their principal challenges and immediate needs.
Methods
This paper collected Weibo posts (N = 1040) containing the keyword “Shanghai Anti-epidemic Help” during the citywide lockdown. The online help requests from Shanghai citizens were analyzed across 7 dimensions, including the help sought, level of urgency, help recipient, the intended beneficiary of the help, expression, position, and emotion.
Results
The study found that the most common requests for assistance were related to social isolation, specifically in the areas of home and community (34.81%), isolation (10.86%), and personal freedom (7.31%). Of all help requests, 11.83% were deemed very urgent. Most of the Weibo posts sent out a plea for help to Internet users (56.06%), primarily requesting help for themselves (26.25%) or their families (27.60%).
Conclusions
The study found that personal freedom, food, and medical care were the most frequently sought help from the public, and most of the public’s positions and emotions were pessimistic. The relevant findings revealed the public’s needs and status during the city closure, providing a reference for emergency preparedness in public health events or emergencies.
Multidimensional computer adaptive testing (MCAT) can provide higher precision and reliability or reduce test length when compared with unidimensional CAT or with the paper-and-pencil test. This study compared five item selection procedures in the MCAT framework for both domain scores and overall scores through simulation by varying the structure of item pools, the population distribution of the simulees, the number of items selected, and the content area. The existing procedures such as Volume (Segall in Psychometrika, 61:331–354, 1996), Kullback–Leibler information (Veldkamp & van der Linden in Psychometrika 67:575–588, 2002), Minimize the error variance of the linear combination (van der Linden in J. Educ. Behav. Stat. 24:398–412, 1999), and Minimum Angle (Reckase in Multidimensional item response theory, Springer, New York, 2009) are compared to a new procedure, Minimize the error variance of the composite score with the optimized weight, proposed for the first time in this study. The intent is to find an item selection procedure that yields higher precisions for both the domain and composite abilities and a higher percentage of selected items from the item pool. The comparison is performed by examining the absolute bias, correlation, test reliability, time used, and item usage. Three sets of item pools are used with the item parameters estimated from real live CAT data. Results show that Volume and Minimum Angle performed similarly, balancing information for all content areas, while the other three procedures performed similarly, with a high precision for both domain and overall scores when selecting items with the required number of items for each domain. The new item selection procedure has the highest percentage of item usage. Moreover, for the overall score, it produces similar or even better results compared to those from the method that selects items favoring the general dimension using the general model (Segall in Psychometrika 66:79–97, 2001); the general dimension method has low precision for the domain scores. In addition to the simulation study, the mathematical theories for certain procedures are derived. The theories are confirmed by the simulation applications.
Missing data occur in many real world studies. Knowing the type of missing mechanisms is important for adopting appropriate statistical analysis procedure. Many statistical methods assume missing completely at random (MCAR) due to its simplicity. Therefore, it is necessary to test whether this assumption is satisfied before applying those procedures. In the literature, most of the procedures for testing MCAR were developed under normality assumption which is sometimes difficult to justify in practice. In this paper, we propose a nonparametric test of MCAR for incomplete multivariate data which does not require distributional assumptions. The proposed test is carried out by comparing the distributions of the observed data across different missing-pattern groups. We prove that the proposed test is consistent against any distributional differences in the observed data. Simulation shows that the proposed procedure has the Type I error well controlled at the nominal level for testing MCAR and also has good power against a variety of non-MCAR alternatives.
In best linear prediction (BLP), a true test score is predicted by observed item scores and by ancillary test data. If the use of BLP rather than a more direct estimate of a true score has disparate impact for different demographic groups, then a fairness issue arises. To improve population invariance but to preserve much of the efficiency of BLP, a modified approach, penalized best linear prediction, is proposed that weights both mean square error of prediction and a quadratic measure of subgroup biases. The proposed methodology is applied to three high-stakes writing assessments.
In this study, a new item response theory model is developed to account for situations in which respondents overreport or underreport their actual opinions on a positive or negativeissue. Such behavior is supposed to be a result of deception and transfer mechanisms. In the proposed model, this behavior is simulated by incorporating a deception term into a multidimensional rating scale model, followed by multiplication by a transfer term, with the two operations performed by an indicator function and a transition matrix separately. The proposed model is presented in a Bayesian framework approximated by Markov chain Monte Carlo algorithms. Through a series of simulations, the parameters of the proposed model are recovered accurately. The methodology is also implemented within an online experimental study to demonstrate the methodology’s application.
This study explores the effects of World Englishes teaching practice in improving EFL learners’ self-confidence in English-speaking performance (SCIESP) with a mixed methodology design comprising both qualitative and quantitative approaches. Data were gathered through a survey with the Self-Confidence in English-speaking Performance Questionnaire, students’ reflective notes, and focus group interviews. Two teaching classes with no significant difference in self-confidence were randomly chosen as the experimental class (EC) and control class (CC). The two classes shared the same teaching implication except that the EC had four lectures on World Englishes while the CC got four lectures on English History. After one semester the research team surveyed students’ SCIESP again. The result showed a remarkable improvement in students’ SCIESP in EC than in CC. It was found that World Englishes teaching contributed significantly to increasing students’ SCIESP.
China is entering a deeply aging society gradually, and individual pension allocation behavior has a profound impact on the practice and effect of national strategies to actively cope with population aging. This paper constructs a dyad model based on the influence path of social network ties in individual commercial pension insurance purchasing decisions, and then validates the path by building a generalized linear mixed model (GLMM) based on Bayesian approach with the national longitudinal sample data of China. The empirical results show that, firstly, strong ties social interaction (e.g., visiting friend's house) positively influences individuals' commercial pension insurance purchase behavior; secondly, the less the frequency of individual social interaction is, the less significant the positive influence of social interaction on individual commercial pension insurance product purchase is; finally, between 2013 and 2018, the intensity and frequency of social interactions among middle-aged and elderly people in China has been changed dramatically by the shock of the popularity and development of digital social tools. The influence of strong ties social interaction on insurance purchase behavior becomes weaker and weaker, while that of weak ties becomes stronger.
Active flow control based on reinforcement learning has received much attention in recent years. Indeed, the requirement for substantial data for trial-and-error in reinforcement learning policies has posed a significant impediment to their practical application, which also serves as a limiting factor in the training of cross-case agents. This study proposes an in-context active flow control policy learning framework grounded in reinforcement learning data. A transformer-based policy improvement operator is set up to model the process of reinforcement learning as a causal sequence and autoregressively give actions with sufficiently long context on new unseen cases. In flow separation problems, this framework demonstrates the capability to successfully learn and apply efficient flow control strategies across various airfoil configurations. Compared with general reinforcement learning, this learning mode without the need for updating the network parameter has even higher efficiency. This study presents an effective novel technique in using a single transformer model to address the flow separation active flow control problem on different airfoils. Additionally, the study provides an innovative demonstration of incorporating reinforcement-learning-based flow control with aerodynamic shape optimization, leading to collective enhancement in performance. This method efficiently lessens the training burden of the new flow control policy during shape optimization, and opens up a promising avenue for interdisciplinary intelligent co-design of future vehicles.
Extant literature shows that small conversations with strangers can help improve individuals’ wellbeing while reducing feelings of loneliness. Nevertheless, previous studies on talking to strangers tend to focus on young participants in controlled experimental settings, leaving a gap in understanding older adults’ experiences and their likelihood of adopting talking to strangers as part of their daily healthy ageing practices. Considering the problem of worsened social isolation and loneliness among older people during the Covid-19 pandemic, it is even more important to include them in the promotion of social inclusion through micro-conversations with strangers. To understand older adults’ attitudes and experiences of talking to strangers, this study interviewed 19 older people based on their trial of talking to strangers over a three-month period. Findings reveal that their willingness and confidence varied by age and gender, with retired individuals being more active in engaging with strangers. Time constraints and lack of self-efficacy were identified as barriers, particularly among those still working or with caregiving responsibilities. Rather than personal gains, the act of kindness towards others was emphasised as the key motive. These insights are valuable for policy makers and organisations supporting older people’s wellbeing, highlighting the potential for older individuals to serve as conversation initiators, promoting mutual kindness and wellbeing in communities.