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Ratio maps of T1w/T2w MRI signal intensity do not improve deep-learning segmentation of pediatric brain tumors
Get PDFINTRODUCTION: T1w/T2w ratio mapping, combining voxel-wise signal intensities in T1-weighted (T1w) and T2-weighted (T2w) structural MRI, has been used to investigate cortical architecture in the brain, but has also shown promise in tissue discrimination, even in tumor tissue. Given this, we investigate whether the inclusion of these established T1w/T2w ratio maps, or a similar T1w - T2w combined map, can improve performance on a novel task; automated segmentation of tumor tissue in pediatric brain tumor cases from the BraTS-PED 2024 dataset. METHODS: Using the BraTS-PED 2024 dataset (n = 261 pediatric brain tumor patients), we trained and evaluated (with a five-fold cross validation approach) segmentation performance across tumor subregions with nnU-Net, a state-of-the-art deep learning framework. Multiple model configurations were compared; a) a standard baseline model using typical multiparametric MRI (mpMRI, including T1w, T2w, FLAIR and contrast-enhanced T1w MRI) as input modalities and b) an experimental configuration using standard mpMRI inputs plus a T1w/T2w ratio map. Performance was assessed using Dice scores and statistical comparisons with Bonferroni correction to assess he direct 'added benefit' of the T1w/T2w ratio maps. RESULTS: Inclusion of T1w/T2w ratio or the combined maps did not significantly improve segmentation accuracy across any tumor subregion. While minor increases in ET segmentation were observed with the ratio map, these were not statistically significant. Combined maps showed marginal improvements in ET and NET segmentation but reduced performance in CC and ED regions. CONCLUSIONS: Overall, we demonstrate that T1w/T2w ratio maps do not improve deep learning models for segmenting pediatric brain tumor subregions using nnU-Net, despite their strong biophysical basis for tissue discrimination. These findings suggest that such data augmentation strategies may not provide added value and highlight the importance of rigorous validation in medical imaging research
Facilitators and barriers to recruitment and retention in a feasibility trial of encapsulated faecal microbiota transplant to eradicate carriage of antibiotic-resistant bacteria at an academic hospital in central London: a nested qualitative study
Get PDFObjectives This nested qualitative study (NQS) aimed to identify facilitators and barriers to the delivery of a substantive randomised controlled trial investigating the eradication of gastrointestinal tract carriage of antibiotic-resistant organisms using encapsulated faecal microbiota transplant (FMT). Design NQS within a participant-blinded, randomised, placebo-controlled, single-centre, feasibility trial (RCT)—Feasibility of ERadicating gastrointestinal carriage of Antibiotic-Resistant Organisms (FERARO) (ISRCTN reg. no. 34 467 677)—with data collected via focus groups and analysed using thematic analysis. Setting RCT participants were recruited from a large academic tertiary referral hospital in central London. Focus groups were held at the hospital or via videoconferencing for those unable to travel. Participants This study included 13 FERARO study participants across two focus groups. 11 participants were under RCT follow-up and unaware of their treatment allocation, two participants had completed 6-month follow-up and knew whether they had received FMT or matched placebo. Additional data were opportunistically collected on reasons for declining RCT participation. Results Participants found FMT to be an acceptable and holistic management strategy and noted positive impacts from RCT participation including enhanced personal health awareness and valuable support from the research team. The time and travel commitment presented the most substantial barrier to RCT participation. Many participants were motivated by a desire to give something back to the UK National Health Service and/or research. Patients’ current health status also influenced the decision-making process, and, while infrequently cited, the COVID-19 pandemic added extra complexity likely impacting individuals’ willingness to participate. Conclusions While FMT is generally acceptable to participants, logistical barriers such as the time and travel commitment associated with RCT participation need consideration. Effective communication, personal connections and participant education on antimicrobial resistance are likely to be crucial for enhancing recruitment and retention in future trials
Digital governance voids and entrepreneurial internationalization
No full textBuilding on the institutional escape perspective, this study explains why the home-country digital governance voids – i.e., the absence, underdevelopment, or fragmentation of digital infrastructure and associated governance mechanisms – may foster the internationalization of entrepreneurial firms in developed economies. It further explains why and how this baseline prediction varies across differing firm sizes and home-country economic opportunities. Using a five-year panel dataset of entrepreneurial firms across European countries, it provides support for the escape perspective, showing that digital governance voids do boost the degree of entrepreneurial firms’ internationalization, particularly for larger entrepreneurial firms and in more opportunity-rich economies. This study offers important theoretical contributions to the institutional theory, the escape perspective, and research on entrepreneurial firm internationalization, and discusses practical implications as well as avenues for future research
JNK3 quantification in plasma:a novel biomarker for neuronal damage in Parkinson's disease
Get PDFDiagnosis of Parkinson's disease (PD) remains challenging due to the lack of reliable biomarkers. To address this need, we quantified plasma levels of brain-specific c-Jun N-terminal kinase 3 (JNK3), a protein involved in neurodegeneration. A total of 108 participants were enrolled, including 25 individuals with isolated REM sleep behavior disorder (iRBD), 26 patients with De Novo PD, 29 with Late PD, and 28 age-matched healthy controls (HC). All subjects underwent clinical assessment, blood sampling, and skin biopsy. Plasma JNK3 levels were significantly elevated in PD and iRBD compared to HC, a finding that remained robust after adjustment for age and sex in multivariate logistic regression. ROC analysis demonstrated that JNK3 levels distinguished PD from HC with 100% specificity and 65% sensitivity in Late PD. In contrast, Neurofilament Light Chain showed non-significant group differences and weak discriminative performance. Notably, while JNK3 declined with age in HC, it increased with age in Late PD (P = 0.048, B = 0.105) and negatively correlated with motor impairment. Elevated JNK3 was also associated with pathological α-Synuclein in skin biopsy. These findings highlight JNK3 as a promising blood biomarker for PD, with meaningful diagnostic and prognostic value, suggesting that its implementation could refine patient stratification and improve clinical trial efficiency. [Abstract copyright: © 2025. The Author(s).
A new bee in the hive:integrating an IoT platform into a multi-business model organization
Get PDFResponding to the urgent need to balance economic performance and environmental, social and governance sustainability, manufacturers are developing new business models that create value through services in addition to their manufacturing activities. This often results in the development of multiple business models within the organization. However, managing multiple business models, especially integrating a new business model into an established organization, is challenging. This study brings together the fragmented discussions of what the challenges are in the business model innovation literature and reveals the underlying causes of the challenges by drawing on organizational boundary theory. This study investigates a representative case, Jianpan Group who integrated a service-oriented IoT platform with its manufacturing-centred business model, which generates valuable insights into the nature of challenges in managing business model portfolios. The managerial practices provide actionable guidance for manufacturers to create synergy and interdependencies across their business models
Crossing the Rubicon: exploring migrants’ transition out of military service into civilian work
Get PDFLeveraging intersectionality as a lens, we explore the life-history accounts of former military migrants (MMs) on their transition out of the military service into civilian work. Data for the inquiry comes from in-depth interviews with MMs from West African Commonwealth countries who joined the UK military between 1998 and 2010. Focusing on the intersectionality of contexts, situatedness, positionalities, and identities of MMs, we theorise how this group of veterans account for their ‘(un)gilded’ transition from military service to joining civilian work. Played out as a process of ‘way-finding’, MMs’ transition out of military service into civilian work, we found, is characterised by four salient tropes: sculpturing an angel in a block of marble; randomness, luck, and chance; figurational support networks; and the show of ‘grace under pressure’. Providing situated insights into the transitioning experiences of MMs, our study delineates how this group of veterans rationalise their career choices and adds nuance to how they draw on their intersecting migrant and veteran identities to respond to and overcome everyday structural barriers. We conclude with a discussion of our findings and their implications for the theory and practice of human resource management and the employment of veterans in civilian work
A dynamic state-space HAR model
Get PDFThe Heterogeneous AutoRegressive model for the logs of Realised Volatility (HARL) has established itself as the benchmark specification for modelling and forecasting return volatility, owing to its parsimony and ability to capture the strong persistence typically observed in RV. To address potential concerns such as measurement errors, nonlinearities, and non-spherical residuals, numerous variants of the baseline HARL model have been developed in the literature. This paper contributes to this body of work by proposing a new class of dynamic state-space models with time-varying parameters. The parameter dynamics are assumed to follow an autoregressive process, with or without stochastic volatility, giving rise to two specifications: SHARP and SHARP-SV. Both models are designed to capture the evolving nature of return volatility and are estimated via Bayesian inference using Particle Gibbs sampling. Empirical applications to high-frequency data on SPY, sector ETFs, representative NYSE stocks, and the VIX index demonstrate that our proposed models on average outperform alternative HARL-based specifications in forecasting volatility, particularly at medium- and long-term horizons. An extensive Monte Carlo analysis further illustrates the advantages of our approach in terms of both estimation accuracy and predictive performance
A meta-heuristic-based framework for sustainable P-hub network design of perishable items under fuzzy time uncertainty
No full textIn this paper, a novel mathematical model is presented for designing a sustainable hub network for perishable commodity transportation, taking into account social responsibility, environmental impact, and economic viability. As many real world problems have non-deterministic parameters, the time parameters are considered fuzzy numbers in the model. To validate the model, the model is solved on a small scale using GAMS software after linearisation. However, due to the non-deterministic polynomial time nature of the problem, an efficient meta-heuristic algorithm is proposed using MATLAB software. The algorithm has been validated on small and medium scale instances using the AP and CAB datasets. The results show that the proposed NSGA-II algorithm achieves an average solution gap of 0.017% while significantly reducing computational time compared to exact methods. The proposed model and algorithm can assist decision makers in designing sustainable and efficient supply chain networks for perishable products
Psychometric Validation of the Simplified Chinese Version of the Dyspnoea-12 Questionnaire for Patients with Primary Lung Cancer
Get PDFPurpose: The simplified Chinese version of the Dyspnoea-12 Questionnaire (D-12) has not yet been translated and validated for patients with primary lung cancer. This study aimed to evaluate the psychometric properties of the simplified Chinese version of the D-12 for patients with primary lung cancer. Methods: This study analysed the baseline data of a randomised controlled trial that used an inspiratory muscle training intervention for patients with thoracic malignancies. The original English version of the D-12 was translated into simplified Chinese according to standard instrument translation and adaptation procedures. The internal consistency reliability of the D-12 was determined by calculating Cronbach’s alpha coefficients. The convergent validity of the D-12 was evaluated by Spearman’s correlation with the Borg CR-10 Scale, Numerical Rating Scale (NRS), Hospital Anxiety and Depression Scale (HADS), and Saint George’s Respiratory Questionnaire (SGRQ). Blood oxygen level, the 6-minute walk test distance, alcohol use, surgery type, cancer stage, exercise level, and educational background were identified to evaluate their discriminating performance. Results: The analysis included 196 participants. The Cronbach’s alpha coefficients for the full D-12 and its physical and emotional function subscales were 0.83, 0.74, and 0.92, respectively. Significantly positive associations were found between the D-12 scores and the Borg CR-10 Scale, the NRS, the HADS, and SGRQ scores (p < 0.01). The participants with insomnia (p < 0.01) and who did not use alcohol (p = 0.019) reported significantly higher D-12 total scores compared with their respective counterparts. The participants at different cancer stages (p < 0.01) and those who had undergone different surgeries (p = 0.033) reported significantly different D-12 total scores. Conclusions: The D-12 simplified Chinese version demonstrated very good psychometric properties and high acceptability in patients with primary lung cancer
Decoding the impact of firm‐level ESG performance on financial disclosure quality
Get PDFThis study examines the impact of environmental, social, and governance (ESG) performance on financial disclosure quality as measured by disaggregated financial statements (FSDQ), using data from US-listed companies between 2002 and 2021. We find a positive association between ESG performance and FSDQ quality, suggesting that improved ESG performance is linked to enhanced disclosure quality and accountability and that managerial competence and strong organizational culture accentuate this relationship. Further analysis shows a stronger link between firms with high-quality accounting practices and good financial reporting readability, whereas complex financial reporting weakens this relationship. Our findings remain valid when alternative measures of key variables are used, and under propensity score analysis, Heckman's two-stage estimation, and cross-lagged and entropy balancing techniques, ensuring the analysis is robust and reliable. Overall, our findings provide important new insights into ESG performance, suggesting it fosters enhanced disclosure and accountability to stakeholders
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