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Refugees in Africa (1490-1820)
Full text linkThe history of Africa is marked by human mobility. A large portion of these movements involve people who can be fully or partially classified as refugees. This chapter focuses on early modern Africa, from the end of the fifteenth century to the very beginning of the nineteenth century. It surveys several major historical events and climate episodes: the LIA, the expulsion of Muslims and Jews from the Iberian Peninsula, and the apex of trans-Atlantic, trans-Saharan and trans-Indian ocean slave trades. It includes North and Sub-Saharan Africa. The chapter explores the causes and consequences of refugee migrations from a threefold perspective: the impact of climate on human mobility; the imperial politics that created refugees and the way expanding empires managed refugees flows; and the effects on African landscapes, cultures and societies
The emotional and financial impact of de-platforming on creators at the margins
Full text linkThis study provides one of the first examples of de-platforming’s direct emotional and financial impact on Instagram and TikTok content creators at the margins. Both platforms provide significant opportunities toward creative and flexible work, allowing creators to maintain networks, promote work, express themselves and earn a living. However, their governance can severely disrupt certain forms of content creation, particularly for users who post online sex work and nude content. Through a qualitative survey, we gathered the experiences of 123 de-platformed Instagram and TikTok users who posted nude or sex work-related content. Our study provides crucial testimonies showing that the precarity of creator labor and platforms’ reliance on automated content moderation have negatively impacted creators’ well-being. Participants faced adverse psychological impacts resulting from job and income uncertainty, associated feelings of powerlessness, a loss of digital identity, and enforced isolation from a previously established social network. We conclude by providing platform governance recommendations based on these experiences
Dynamic Rail Near-Surface Inspection of Multiphysical Coupled Electromagnetic and Thermography Sensing System
Full text linkThe effectiveness of railway fault inspection has remained challenging. Conventional techniques are still functionally limited and unable to meet the increasing demand of railway diagnosis. To mitigate the variety of rail fault detection problems, this article proposes a dynamic railway inspection system based on multiphysical coupled electromagnetic and thermography sensing. It further shows the development and construction of a new inverted L-type magnet yoke abreast with volumetric coil array. The novel structure can not only significantly enhance the sensitivity and detectability of the region of interest (ROI), but also effectively detect the subsurface defects with the compensation of coils array due to the coupled electromagnetic field. Furthermore, the theoretical analysis of the coupled physical fields has been derived and proved to be consistent with the numerical simulation results. A rail test sample with various defects is carried out to verify the feasibility of the proposed system. Additionally, a metric learning post-processing algorithm has been conducted for distilling eddy current signals and thermograms to improve the accuracy of the detection results. On-site experimental and contrast results with various levels of performance validation have demonstrated that the integrated system is well suited for dynamic rail inspection on near-surface cracks at speed of 1 km/h
Global Solar Radiation Forecasting Based on Hybrid Model with Combinations of Meteorological Parameters: Morocco Case Study
Full text linkThe adequate modeling and estimation of solar radiation plays a vital role in designing solar energy applications. In fact, unnecessary environmental changes result in several problems with the components of solar photovoltaic and affects the energy generation network. Various computational algorithms have been developed over the past decades to improve the efficiency of predicting solar radiation with various input characteristics. This research provides five approaches for forecasting daily global solar radiation (GSR) in two Moroccan cities, Tetouan and Tangier. In this regard, autoregressive integrated moving average (ARIMA), autoregressive moving average (ARMA), feed forward back propagation neural networks (FFBP), hybrid ARIMA-FFBP, and hybrid ARMA-FFBP were selected to compare and forecast the daily global solar radiation with different combinations of meteorological parameters. In addition, the performance in three approaches has been calculated in terms of the statistical metric correlation coefficient (R²), root means square error (RMSE), stand deviation (σ), the slope of best fit (SBF), legate’s coefficient of efficiency (LCE), and Wilmott’s index of agreement (WIA). The best model is selected by using the computed statistical metric, which is present, and the optimal value. The R² of the forecasted ARIMA, ARMA, FFBP, hybrid ARIMA-FFBP, and ARMA-FFBP models is varying between 0.9472 and 0.9931. The range value of SPE is varying between 0.8435 and 0.9296. The range value of LCE is 0.8954 and 0.9696 and the range value of WIA is 0.9491 and 0.9945. The outcomes show that the hybrid ARIMA–FFBP and hybrid ARMA–FFBP techniques are more effective than other approaches due to the improved correlation coefficient (R2)
COVID-19 and organized crime: an introduction to the special issue
Full text linkThis is an introduction to the articles submitted to the special issue of Trends in Organized Crime on ‘COVID-19 and Organized Crime’. The aim of the special issue is to draw together a range of empirical studies from around the world to explore the implications of the COVID-19 pandemic for both organized criminals and law enforcement agencies. The pandemic required organized criminals to adapt their practice in light of government restrictions, but it also created new profitable opportunities. At the same time, however, COVID-19 posed significant challenges for law enforcement
Incorporating microglia‐like cells in human induced pluripotent stem cell‐derived retinal organoids
Full text linkMicroglia are the primary resident immune cells in the retina. They regulate neuronal survival and synaptic pruning making them essential for normal development. Following injury, they mediate adaptive responses and under pathological conditions they can trigger neurodegeneration exacerbating the effect of a disease. Retinal organoids derived from human induced pluripotent stem cells (hiPSCs) are increasingly being used for a range of applications, including disease modelling, development of new therapies and in the study of retinogenesis. Despite many similarities to the retinas developed in vivo, they lack some key physiological features, including immune cells. We engineered an hiPSC co-culture system containing retinal organoids and microglia-like (iMG) cells and tested their retinal invasion capacity and function. We incorporated iMG into retinal organoids at 13 weeks and tested their effect on function and development at 15 and 22 weeks of differentiation. Our key findings showed that iMG cells were able to respond to endotoxin challenge in monocultures and when co-cultured with the organoids. We show that retinal organoids developed normally and retained their ability to generate spiking activity in response to light. Thus, this new co-culture immunocompetent in vitro retinal model provides a platform with greater relevance to the in vivo human retina
Sport Participation for People with Disabilities: Exploring the Potential of Reverse Integration and Inclusion through Wheelchair Basketball
Full text linkReverse integration is defined as the inclusion of able-bodied people into disability sport. For decades, there have been movements towards integrating people with a disability in mainstream society. There has been a lack of research supporting the movement of able-bodied involvement in disability sport, known as reverse integration. In this study, the real-life experiences and motivations of 11 national wheelchair basketball players (four able-bodied and seven with a disability) were explored, identifying the potential of reverse integration and what influenced the players involvement. Thematic analysis was employed using a deductive approach. The social-relational model was used as a framework to help interpret the findings. The results highlighted that health and social benefits were key factors towards prolonged engagement in wheelchair basketball, and it was reported that reverse integration led to an increased mutual understanding of the impact of (dis)ability. All participants reported positive experiences and supported able-bodied involvement, suggesting that able-bodied players play a key role and help to grow the sport locally. However, involvement of able-bodied players was not supported at international level. This challenges the concept of inclusion at higher level and whether the sport could be more inclusive. These findings could provide direction to coaches and policymakers for developing further inclusive opportunities at all levels. Further research may explore coach education programs and learning experiences of becoming an inclusive coach to ensure coaches know how to create, stimulate and coach in inclusive sport environments
The Role of Cognition and Social Factors in Competition: How Do People with Intellectual Disabilities Respond to Opponents?
Full text linkExploring pacing behaviour in people with intellectual disabilities (ID) in competition will help to better understand the impact of cognition and social environment in sports, providing support for the shaping of proper inclusive sports environments. The present experimental study aimed to (1) compare the pacing behaviour and performance between people with and without ID who are inexperienced in cycling and (2) investigate how these are influenced by an opponent. Participants with (n = 8) and without ID (n = 10) performed two randomised 4-km maximal cycling trials, alone and against an opponent. Non-parametric tests for repeated measures data (p ≤ 0.05) revealed that people with ID cycled slower, but with higher inter-individual variation (both conditions) and paced themselves differently compared to people without ID when competing against an opponent. In contrast to the previous literature in athletes without ID, the presence of a faster opponent resulted in a decrease in the performance in the participants with ID. The negative influence of the opponent highlights the potential difficulties people with ID experience to adequately use their opponents to enhance their self-regulatory processes and optimize their pacing and performance in maximal exercise trials. Coaches who want to offer inclusive sports environments for people with ID could take these findings into consideration
Modelling and design of hierarchical fibre-graphene nanoplatelets reinforced elasto-viscoplastic polymer matrix composites to improve crashworthiness and energy absorption
Full text linkToday, light-weighting for energy efficiency without sacrificing safety and performance attributes has become a primary focus in the automotive industry. In the field of modelling graphene nanocomposites' structural applications under severe loading conditions, literature is limited. In addition, the existing work only employs the so-called one-site (OS) modelling. This study develops an approach to study 3-phases hierarchical fibres/graphene nanoplatelets (GNPs)-reinforced polymer matrix composites utilising OS modelling and what is known as multi-site (MS) modelling. The MS modelling accounts for material anisotropy considering the interaction between neighbouring inclusions. Applicability of both models is then assessed for automotive components' crashworthiness response under combined mechanical and rate-dependent plasticity or viscoplasticity behaviours. A coherent micromechanical design is employed with elastic platelets and elasto-viscoplastic matrix assumptions. The micromechanics modelling combines rate-dependent constitutive laws and thermomechanical properties for the nonlinear response of composite materials. The heterogeneous material problem is resolved in the first instance for a thermoelastic case. The thermomechanical kinematic integral equation is used to derive the strain concentration tensor. Using the generalised Mori–Tanaka (GMT) homogenisation scheme, effective thermomechanical properties are obtained. For the nonlinear behaviour, a linearisation of the classical J2 rate-dependent model is considered with an isotropic hardening. Based on an implicit integration scheme, a consistent tangent modulus is obtained and serves as a uniform modulus for homogenisation of the rate-dependent thermomechanical composite material. An application is therefore performed on a short glass -fibres/graphene nanoplatelet/ Polyamide-Nylon 6 (GNP/PA6) composite. The current study's archival value is to provide an auspicious approach for a consistent design and application of this category of materials for automotive structural components
On the Accuracy, Media Representation, and Public Perception of Psychological Scientists’ Judgments of Societal Change
Full text linkAt the onset of the COVID-19 pandemic, psychological scientists frequently made on-the-record predictions in public media about how individuals and society would change. Such predictions were often made outside these scientists’ areas of expertise, with justifications based on intuition, heuristics, and analogical reasoning (Study 1; N = 719 statements). How accurate are these kinds of judgments regarding societal change? In Study 2, we obtained predictions from scientists (N = 717) and lay Americans (N = 394) in Spring 2020 regarding the direction of change for a range of social and psychological phenomena. We compared them to objective data obtained at 6 months and 1 year. To further probe how experience impacts such judgments, 6 months later (Study 3), we obtained retrospective judgments of societal change for the same domains (Nscientists = 270; Nlaypeople = 411). Bayesian analysis suggested greater credibility of the null hypothesis that scientists’ judgments were at chance on average for both prospective and retrospective judgments. Moreover, neither domain-general expertise (i.e., judgmental accuracy of scientists compared to laypeople) nor self-identified domain-specific expertise improved accuracy. In a follow-up study on meta-accuracy (Study 4), we show that the public nevertheless expects psychological scientists to make more accurate predictions about individual and societal change compared to most other scientific disciplines, politicians, and nonscientists, and they prefer to follow their recommendations. These findings raise questions about the role psychological scientists could and should play in helping the public and policymakers plan for future events