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Continental shift: operations and supply chain management research from an African perspective
No full textPurpose – Africa is attracting growing research interest in operations and supply chain management (OSCM). However, the implications of Africa’s contexts are understudied and need to be explored to refine and elaborate existing OSCM theories and concepts or develop new ones. This paper addresses these limitations while introducing IJOPM’s Africa Initiative (AfIn), which seeks to provide a platform and support for Africa-based researchers and the broader OSCM community to advance OSCM research on and from Africa.
Design/methodology/approach – This conceptual paper draws on multiple streams of literature to disentangle and better understand African contexts and discuss how the continent’s idiosyncrasies can enrich OSCM research. It then details the AfIn, including its motivation and objectives, the review process, and support mechanisms for researchers.
Findings – The paper sheds light on seven contextual factors that may influence OSCM research in Africa: (i) informal economy and organizations; (ii) socio-cultural diversity and complexity; (iii) traditional and survival-oriented cultures; (iv) weak formal institutions with strong informal institutions; (v) population growth potential; (vi) abundant resources with low outcomes; and (vii) high environmental constraints. Additionally, the paper provides insights into how these contextual factors underpin five OSCM themes through which future research can advance and shape OSCM theory and practice. These themes include: (i) serving consumer markets; (ii) managing resources; (iii) managing factor market rivalry; (iv) managing environmental hostility; and (v) managing institutions.
Originality/value – The paper provides a comprehensive and in-depth understanding of Africa’s contextual idiosyncrasies and their implications for OSCM theory and practice. In doing so, it reveals intriguing, yet underexplored, OSCM phenomena about the continent while laying out actionable pathways through which research using African data can make novel theoretical contributions
Marker density of optical tactile sensor for moving object tracking
No full textSoft tactile sensors have the ability to infer more physical properties of an object relative to classical optical motion-capture systems. Three marker densities in a tactile sensor array (the Motion Capture Pillow, MCP) were evaluated for tracking two rotary motions using a weighted mannequin head. The Kanade–Lucas–Tomasi algorithm was employed to track head movements using three silicone sheets, each embedded with different marker spacings (5, 10, and 15 mm). The averaged Spearman’s correlation slightly changed from 0.80 (for 10 mm spacing) to 0.67 (for 5 mm spacing) for pitch motion and from 0.68 (for 10 mm spacing) to 0.59 (for 5 mm spacing) for roll motion of the mannequin head with respect to the MCP’s frame. A correlation of +1.0 being the strongest positive correlation and 0.0 being weak correlation. The MAE reduced by 12.9% from matrix with 10 mm spacing to 5 mm spacing for pitch motion, and by 2.9% for roll motion. This established a foundation for further tuning the sensor using a higher density of the sensing matrix. The relatively sparsely dense sensor matrix with 15 mm spacing had minimal impact on the tracking performance of the sensor. Sources of noise were narrowed down to hysteresis, and boundary conditions. These results demonstrated the influence of marker density on the object tracking abilities of an optical soft tactile sensor, and established a basis for future optimisation
Validating the children's eating behaviour questionnaire in a UK sample: A suitable tool for mothers and fathers
No full textChildren's eating behaviour is a complex construct linked to various health, social, and psychological outcomes. The Children's Eating Behaviour Questionnaire (CEBQ)assesses parents' perceptions of children's eating behaviours across eight subscales: food fussiness, enjoyment of food, food responsiveness, satiety responsiveness, desire to drink, slowness in eating, and emotional under- and overeating. Given that the initial validation of the CEBQ dates back to the early 2000s, this study aimed to (1) evaluate the psychometric properties of the CEBQ in a UK sample using current psychometric recommendations and (2) examine its measurement invariance based on parental sex. A total of 994 caregivers (196 fathers and 798 mothers) of children aged 3–5 years completed the questionnaire. The performance of the scale revealed that 23 items exhibited ceiling or floor effects or failed to meet recommended item-total correlation coefficients. Exploratory factor analysis supported an eight-factor, 34-item structure, which was confirmed via confirmatory factor analysis: X2 = 2129.845 (df = 499; p < 0.001), TLI = 0.911, CFI = 0.921, RMSEA = 0.083 (90 % CI 0.079–0.087) and SRMR = 0.080. All factors demonstrated adequate internal consistency (omega 3 values over 0.7). Measurement invariance testing confirmed strict invariance by parental sex, indicating the instrument performs equivalently for mothers and fathers. These findings support the use of the revised 34-item CEBQ with its eight original factors for both maternal and paternal respondents. However, future research should consider revising certain CEBQ items included to strengthen its capacity to capture variations in children's eating behaviour, and to provide a more accurate evaluation of the construct
Does peer learning improve local government capacity to improve sanitation? A contribution analysis in rural Mozambique
No full textStrengthening local government capacity to improve sanitation and other basic services is a challenge in many low resource countries. There is growing interest in peer learning as a mechanism to spread successful practices and increase local government performance in the settings. However, few studies have investigated if peer learning leads to changes in practices and improved results. The study aims to identify and evaluate the causal linkages between peer learning activities and any changes to participants capacity, local government practices and increases in sanitation coverage in rural districts. Contribution Analysis, a theory-based evaluation approach, was used to design a longitudinal study investigating outputs, outcomes and impacts of two peer learning workshops between Open Defecation Free (ODF) Districts and non-ODF Districts in Mozambique alongside the enablers and barriers to change. The research draws on a survey of 66 participants directly after the workshops and 29 semi-structured follow-up interviews nine months later. We found that despite broader structural challenges that hinder progress in sanitation service provision, the workshops enabled the spread of knowledge of good practices (outputs) some of which were replicated (outcomes). There is evidence that these replicated practices accelerated progress towards ODF status (impact) in some districts. We demonstrate that under the right conditions peer learning can nurture local learning, improve knowledge, spread frugal practices and lead to incremental improvements in local government performance. We therefore recommend it be integrated into broader programmes to maximise benefits
CT scoring system to defined thrombus distribution in chronic thromboembolic pulmonary hypertension
No full textObjectives
Characterization of thrombus is important for guiding treatment in chronic thromboembolic pulmonary hypertension (CTEPH). This study presents a novel scoring system for visual assessment of CTEPH on CT pulmonary angiography (CTPA), incorporating both disease location and extent to determine the impact on survival outcomes.
Methods
Patients with CTEPH were identified retrospectively from the Assessing the Spectrum of Pulmonary Hypertension Identified at a Referral Centre registry. The scoring system emphasizes disease based on their predominant location as central, segmental, and distal disease. Survival analysis was conducted using Cox-regression and Kaplan–Meier survival curves.
Results
A total of 208 patients with CTEPH were included (mean age 66 ± 13.6 years, 52.4% female). Mosaic perfusion and infarction were commonly seen in patients with distal disease (92% and 88%). Patients with central and distal disease had more severe pulmonary hemodynamics and lower gas transfer (TLCO) than patients with segmental disease. Central and distal disease showed similar survival, whereas survival was worse in central compared to segmental disease for all patients (P < .001), including those undergoing (P < .04) and not undergoing endarterectomy (P < .001). Central disease was an independent predictor of mortality in those not undergoing endarterectomy (hazard ratio 1.9, P < .01).
Conclusions
Our scoring system showed excellent interobserver agreement. Thromboembolic disease location was shown to be a predictor of mortality, with central disease independently associated with shorter survival in patients not undergoing pulmonary endarterectomy.
Advances in knowledge
This is a novel scoring system for characterizing CTEPH on CTPA, considering disease location and extent. It provides disease location as a predictor of survival, introducing a new framework for patient stratification and clinical decision-making
Should We Embark on “EMBARK”? Reassessing the Role of Radiotherapy and Androgen Receptor Pathway Inhibitors in the Era of Next-generation Imaging
No full textResults from the EMBARK trial reshape the treatment paradigm for high-risk biochemical recurrence of prostate cancer. EMBARK data support the use of androgen receptor pathway inhibitors combined with metastasis-directed therapy in a personalized, multidisciplinary care approach for this subset of patients
Thermal response of hybrid steel-timber floor cross-sections exposed to standard fire: experimental and numerical investigations
No full textHybrid systems that combine steel beams with cross-laminated timber (CLT) floor slabs can be vulnerable to fire, given the combustible nature of timber. Specifically, when unprotected, heat from a fire can conduct through steel beams to the CLT panels, which in turn may experience loss of mechanical properties, and possible charring (and combustion) in the connection zone between the CLT panel and the steel beam. Accordingly, this paper aims to establish thermal profiles in hybrid steel-timber floor cross-sections exposed to fire through experimental and numerical investigations. Results from fire tests and numerical validation studies on hybrid cross-sections exposed to a standard fire are presented; a total of six experiments with unprotected, partially protected, and fully protected steel sections were conducted following an ISO 834-1 standard fire exposure. Furthermore, a two-dimensional numerical heat transfer model was developed using SAFIR software, to predict the evolution of temperatures in the hybrid cross-section. The results confirm that passive fire protection of the steelwork using intumescent coatings plays a key role in determining the extent of charring in the connection region between the CLT panel and the steel section. In addition, temperature predictions from the developed numerical model show reasonable agreement with the experimental measurements
Waiting around for Unruh
No full textHow long does a uniformly rotating observer need to interact with a quantum field in order to register an approximately thermal response due to the circular motion Unruh effect? We address this question for a massless scalar field in dimensions, defining the effective temperature via the ratio of excitation and de-excitation rates of an Unruh-DeWitt detector in the long interaction time limit. In this system, the effective temperature is known to be significantly smaller than the linear motion Unruh effect prediction when the detector's energy gap is small: the effective temperature tends to zero in the small gap limit, linearly in the gap. We show that a positive small gap temperature at long interaction times can be regained via a controlled long-time-small-gap double limit, provided the detector's coupling to the field is allowed to change sign. The resulting small gap temperature depends on the parameters of the circular motion but not on the details of the detector's switching. The results broaden the energy range for pursuing an experimental verification of the circular motion Unruh effect in analogue spacetime experiments. As a mathematical tool, we provide a new implementation of the long interaction time limit that controls in a precise way the asymptotics of both the switching function and its Fourier transform
The Battle for Interpretation:The 1826 Chatterton Massacre and “Riot as Denial”
No full textThis article evaluates the usefulness of Stan Cohen’s ‘techniques of denial’ (2001) for understanding how the discourse of ‘riot’ is deployed in response to accusations of state violence against those engaged in social protest. It does so through a historical case study defined by the state as a ‘riot’: the Pennine Lancashire working-class protests, and most notably, the killings at Chatterton, in April 1826. By examining how the state used techniques of historical, literal, and interpretive denial to obscure both the motivations of the protesters and the violence of the state, the article highlights the ways in which these dominant narratives uphold existing power relations. We further develop Cohen’s work by applying a dialogical lens (Bakhtin, 1981; Steinberg, 1999), which foregrounds the multivocal struggle over meaning between state and subaltern actors. In doing so, we introduce the concept of ‘dialogical acknowledgement’ – a deliberate counter-strategy to denial that affirms protestors’ narratives, reclaims historical truth, and challenges dominant frames. Conceptualising Chatterton as an essentially contested event, the article examines how campaigns and commemorative work have begun to subvert official memory and redefine the moral legitimacy of the state. Ultimately, we argue that interpretive struggles over the language of ‘riot’ are not only historical but political, shaping contemporary efforts to contest denial and restore epistemic justice
The emergence of nature-based solutions in Latin American urban policies: a critical review. The case of Bogotá, Buenos Aires, Santiago de Chile and São Paulo.
No full textLatin America, where over 80% of the population lives in cities, faces urgent challenges in supporting biodiversity, strengthening climate resilience, and fostering urban well-being and social cohesion. Nature-based solutions (NbS) offer a valuable approach to addressing these socio-environmental issues. However, NbS remain largely driven by Global North perspectives and its development in Latin American remains a question. In this research, we examine how NbS are being integrated into urban policies and plans through four case studies in Bogotá (Colombia), Buenos Aires (Argentina), Santiago (Chile), and São Paulo (Brazil). We combined a literature review, to assess how NbS are theoretically conceptualized and perceived in the region, with an analysis of official policy documents, to identify how the concept is being incorporated into local planning. We then analysed both datasets together to understand what NbS integration in urban policies should entail in the region. Our findings show that NbS integration is still at an early stage, with clear disparities in the policies between global and local agendas. Greater efforts and practical experiences are needed to align the concept with local realities and to strengthen its role in policy discourse. To respond to this gap, we identify five key factors that can support both the integration and advancement of NbS in Latin American urban policies and serve as guidance for other cities in the region. We conclude that advancing NbS in Latin America requires a systemic, context-specific approach, grounded in local knowledge and priorities, and sustained through joint efforts and political commitment