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Novel antenna array configuration using miniature double box branch-line couplers for wideband circularly polarised applications
Get PDFThis paper presents a wideband circularly polarized (CP) antenna array using a miniaturized double box branch-line coupler. This was achieved by creating a slow wave structure by introducing open-circuit stubs on the inside arms of the branch-line coupler. The 2×2 antenna array is made of four CP slot radiating elements excited through 1×4 feeding network. Moreover, sequentially rotation method is used to increase the axial-ratio (AR) bandwidth of the array. The CP slot radiating element is fed by coplanar waveguide (CPW). The feedline of the horn-shaped radiator includes a circular matching stub. Ground connected asymmetric T-shaped stub, a pair of grounded L-shaped square strips, and single strip line are shown to induce CP and enhance the antenna’s 3 dB impedance bandwidth and AR performance. The antenna constituting the array has impedance bandwidth of 2.45 GHz from 4.8-7.25 GHz that corresponds to a fractional bandwidth of 40%, and its 3 dB axial-ratio extends between 4.8-6.25 GHz. Compared to a conventional double-box branch-line coupler the size of the proposed coupler is reduced by 35% by increasing the capacitance of the coupler’s arms. This also is shown to increase the impedance bandwidth of the coupler. A 2×2 array was fabricated, and its performance verified. Measured results confirm the proposed antenna array exhibits CP covering the bands of WiMAX IEEE 802.16, C-band and ITU-R F386.9. The measured 3 dB AR bandwidth of the antenna array extend from 3 GHz to 7.3 GHz and its impedance bandwidth extends from 3.2 GHz to 9.0 GHz. The antenna array radiates with a peak gain of 11.5 dBic
Book review : Systems of suffering: dispersal and the denial of asylum
No full textA book review of: Systems of suffering: dispersal and the denial of asylum by Jonathan Darling. London: Pluto Press, 2022. 237 pp. £19.99 (pbk)
ISBN 9780745340487.
This is a useful, forthright and critical account of the UK’s regime for accommodating those asylum seekers who are not held in detention. Rather than offering a dry overview with statistics, and lots of administrative and policy detail, the story is enlivened and underpinned by direct testimony from asylum seekers and support workers in four cities - Glasgow, Cardiff, Sunderland and Birmingham. As the title indicates, the pervasive theme is that the regime inflicts ‘systems of suffering’ or structural violence, which sustain a hostile environment for asylum seekers
D2WFP: a novel protocol for forensically identifying, extracting, and analysing deep and dark web browsing activities
Get PDFThe use of the unindexed web, commonly known as the deep web and dark web, to commit or facilitate criminal activity has drastically increased over the past decade. The dark web is a dangerous place where all kinds of criminal activities take place, Despite advances in web forensic techniques, tools, and methodologies, few studies have formally tackled dark and deep web forensics and the technical differences in terms of investigative techniques and artefact identification and extraction. This study proposes a novel and comprehensive protocol to guide and assist digital forensic professionals in investigating crimes committed on or via the deep and dark web. The protocol, named D2WFP, establishes a new sequential approach for performing investigative activities by observing the order of volatility and implementing a systemic approach covering all browsing-related hives and artefacts which ultimately resulted in improving the accuracy and effectiveness. Rigorous quantitative and qualitative research has been conducted by assessing the D2WFP following a scientifically sound and comprehensive process in different scenarios and the obtained results show an apparent increase in the number of artefacts recovered when adopting the D2WFP which outperforms any current industry or opensource browsing forensic tools. The second contribution of the D2WFP is the robust formulation of artefact correlation and cross-validation within the D2WFP which enables digital forensic professionals to better document and structure their analysis of host-based deep and dark web browsing artefacts
The role of ventral tegmental area in chronic stroke rehabilitation: an exploratory study
Get PDFIntroduction:
The acknowledged role of external rewards in chronic stroke rehabilitation, offering positive reinforcement and motivation, has significantly contributed to patient engagement and perseverance. However, the exploration of self-reward’s importance in this context remains limited. This study aims to investigate the functional connectivity of the ventral tegmental area (VTA), a key node in the brain’s reward circuitry, during motor task-based rehabilitation and its correlation with the recovery process.
Methods:
Twelve right-handed healthy volunteers (4 men, 8 women, aged 57.4 ± 11.3 years) and twelve chronic stroke patients (5 men, 7 women, aged 48.1 ± 11.1 years) with clinically significant right-sided motor impairment (mean FM-UE score of 27.6 ± 8.7) participated. The analysis employed the CONN toolbox to assess the association between motor tasks and VTA connectivity using psychophysiological interaction (PPI).
Results:
PPI analysis revealed motor-dependent changes in VTA connectivity, particularly with regions within the motor circuitry, cerebellum, and prefrontal cortex. Notably, stronger connectivity between the ipsilesional VTA and cerebellum was observed in healthy controls compared to chronic stroke patients, highlighting the importance of VTA-cerebellum interactions in motor function. Stroke patients’ motor performance was associated with VTA modulation in areas related to both motor tasks and reward processing, emphasizing the role of self-reward processes in rehabilitation. Changes in VTA influence on motor circuitry were linked to improvements in motor performance resulting from rehabilitation.
Discussion:
Our findings underscore the potential of neuroimaging techniques in quantifying and predicting rehabilitation outcomes by examining self-reward processes. The observed associations between VTA connectivity and motor performance in both healthy and stroke-affected individuals emphasize the role of psychological factors, particularly self-reward, in the rehabilitation process. This study contributes valuable insights into the intricate interplay between reward circuits and motor function, highlighting the importance of addressing psychological dimensions in neurorehabilitation strategies
Genomic diversity and virulence genes characterization of Bacillus cereus sensu lato isolated from processing equipment of an Algerian dairy plant
Get PDFBacillus cereus is a ubiquitous spore-forming bacterium causing food spoilage. In this study, seventeen B. cereus were isolated from dairy processing equipment in Algeria and characterized. The pathogenic potential genes encoding hemolysin, nonhaemolytic enterotoxin, cytotoxin K and emetic toxin were investigated by PCR. Phylogeny and genetic markers for antimicrobial resistance and virulence were analyzed using whole-genome sequencing data using the Illumina MiSeq® technology. The identity of the isolated strains was confirmed as B. cereus sensu lato and the sequencing of the panC gene clustered 64.7% of them in phylogenetic group III and 35.3% in group IV. The results of PFGE showed that 8 (47.1%), 4 (23.5%), 3 (17.6%) and 2 (11.8%) were differentiated into four groups A, B, C and D, respectively. Each of the two panC phylogenetic groups contains two different types of isolates corresponding to PFGE group (A and C) and (B and D) for phylogenetic groups III and IV, respectively. None of the 14 isolates carried the emetic toxin (ces) gene, whereas other toxin genes were variably detected. Genotyping assigned all isolates to three different sequence types (ST 2226, ST1018 and ST1431) while one clonal complex (CC-142) was identified in three isolates. Hierarchical clustering with a threshold of 500 core genome single nucleotide polymorphism (cgSNPs) differences grouped the strains into three clusters while two strains were less than 20 SNPs different. Three B. cereus (25%) contained three enterotoxic HBL complex-encoding genes hblA/C/D. Enterotoxic NHE complex-encoding genes (nheA/B/C) and the ctyK1 gene were detected in all isolates. The overall results highlight the risk due to toxins produced by the B. cereus group in the food safety and dairy industries in Algeria. This study emphasized the potential of whole-genome sequencing for genotyping and predicting the virulence-associated genes and antimicrobial resistance. The present study will help to better assess the health and spoilage risk associated with B. cereus in dairy processing plants and to incorporate adequate preventive measures
Using thematic analysis to apprehend teachers experiences of working with traumatized students
No full textTeachers can play a significant role in the development of each and every student they meet. Not only is there an expectation of teachers to assist students transition from novice to expert within a subject, but teachers are also assumed to help students from a variety of backgrounds to navigate their emotions through guidance and pastoral support. This chapter presents the findings gathered through a series of semi-structured interviews that explored trauma. Specifically, the chapter discusses the use of thematic analysis in recognising and better understanding the experiences of and impact on teachers’ when working with traumatised students. This chapter explains the method employed to explore the experiences of teachers who have worked with students who have been traumatised by asking questions such as: To what extent do teachers believe their ability to teach is impacted by student trauma? How is student trauma navigated by teachers? To help answer these research questions, thematic analysis was applied, and three key themes emerged from the data. Taken together, the themes Discovered Emotional Turmoil, Resilience, and Strategies for Coping, capture the shared experiences that working with traumatised students has both positively and negatively on teachers’ ability to carry out their role effectively. The chapter closes with suggestions for further avenues of investigation in the field
Book review: The urban enigma: time, autonomy and postcolonial transformation in Latin America by Simone Vegliò
Get PDFIn The urban enigma: time, autonomy and postcolonial transformation in Latin America, Simone Vegliò discusses some dilemmas in forming a post-colonial Latin American urban space based on three major architectural projects in Buenos Aires, Mexico City, and Brasília. The book discusses the projects’ ambitions in line with the vision of modernity at their time while contrasting their aims with the demands of social inclusion, justice, and the continuation of colonial ideas
Advancing the embedding framework: using longitudinal methods to revisit French highly skilled migrants in the context of Brexit
Get PDFThere has been exponential growth in research about the impact of Brexit on the plans and projects of EU migrants in the UK. Much research focuses on highly visible migrants, such as the Poles. By focusing on French highly skilled migrants in London, our paper offers the perspectives of those who, prior to the referendum, were relatively invisible and largely absent from anti-immigration discourses. In so doing, we consider how the shock of Brexit exposed but also threatened the previously taken for granted privileges enjoyed by this capital-rich migrant population. Moreover, our longitudinal data, gathered through repeated interviews over seven years (2011-2018), enables analysis of how participants’ experiences and evaluations of life and work in the UK changed, over time, in response to Brexit. In analysing these longitudinal qualitative data from an under-researched migrant group, this paper also aims to advance our concept of embedding, in its differentiation across political, economic and relational domains, to understand change over time. Specifically, this paper advances understanding of how processes of embedding, both in their reflexive and tacit forms, frame the complex and nuanced ways in which our French highly skilled participants have experienced, made sense of, and responded to, Brexit
Using podcasts to cultivate learner-teacher rapport in Higher Education settings
Get PDFDeveloping rapport with learners has presented challenges for Higher Education teaching practitioners since the onset of the COVID-19 pandemic, and increasingly practice within synchronous/ asynchronous online learning environments. Podcasts are of renewed interest as a digital learning resource in this context. We explored, inductively, views of podcasts designed for teaching and learning purposes from students (n = 11) and practitioners (n = 5) in two disciplinary settings. Textual feedback on two sample podcasts per student were subjected to content analysis. Findings underscored podcasts value as digital learning resources to help nurture teacher-student relations. Podcasts may help establish teacher credibility, may help teachers feel more familiar/approachable to learners and may provide an outlet to communicate in a kind, informal tone to attenuate learning-related anxiety. We draw on findings from our small-scale exploratory study to present practical guidance for developing podcasts designed (in part) to cultivate teacher-student rapport
Jeju 4:3 memorial: Jeju Island, South Korea
Get PDFThis chapter addresses Korea’s difficult past and how it has become the object of the dark tourist’s gaze. Following an overview of dark tourism in South Korea, it centres on approaches to victims of state crime through the case of the memorialisation of the 1948 Jeju 4:3 massacre of insurgents and civilians: an atrocity that occurred in the run-up to the Korean War