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Scalability in incumbent firms:The case of Nvidia
Get PDFScalability refers to the organizational capabilities required to facilitate a smoother and faster scaling process. Although it is usually associated with new ventures, this study explores how established firms can also create conditions conducive to scalability. We address this question by applying an inductive, narrative-based approach to a longitudinal, single-case study of Nvidia Corporation, a company founded in 1993 that since 2006 has undergone a profound transformation driven by the AI revolution. This case study draws on digital archives, including objective accounting information on Nvidia and its direct competitors, extensive company reports, pedagogical case studies, corporate biographies, and 464 minutes of recorded documentaries and interviews featuring the company’s CEO. We use these sources to develop a multi-phase theoretical model outlining how established organizations can foster scalability. The model encompasses value recognition driven by systemic industry transitions, organizational adaptability, strategic renewal, and scalability, thus offering a structured framework for understanding how incumbent firms can cultivate the necessary conditions for successful scaling
The impact of signal variability on COVID-19 epidemic growth rate estimation from wastewater surveillance data
Get PDFTesting samples of wastewater for markers of infectious disease became a widespread method of surveillance during the COVID-19 pandemic. While these data generally correlate well with other indicators of national prevalence, samples that cover localised regions tend to be highly variable over short time scales. Here we introduce a procedure for estimating the real-time growth rate of pathogen prevalence using time series data from wastewater sampling. The number of copies of a target gene found in a sample is modelled as time-dependent random variable whose distribution is estimated using maximum likelihood. The output depends on a hyperparameter that controls the sensitivity to variability in the underlying data. We apply this procedure to data reporting the number of copies of the N1 gene of SARS-CoV-2 collected at water treatment works across Scotland between February 2021 and February 2023. The real-time growth rate of the SARS-CoV-2 prevalence is estimated at all 121 wastewater sampling sites covering a diverse range of locations and population sizes. We find that the sensitivity of the fitting procedure to natural variability determines its reliability in detecting the early stages of an epidemic wave. Applying the same procedure to hospital admissions data, we find that changes in the growth rate are detected an average of 2 days earlier in wastewater than in hospital admissions. In conclusion, this paper provides a robust method to generate reliable estimates of epidemic growth from highly variable data. Applying this method to samples collected at wastewater treatment works provides highly responsive situational awareness to inform public health.</p
Evaluating the implementation of a ward-based training programme within an intensive psychiatric care unit using Normalisation Process Theory
Get PDFBackground: Strong staff-patient relationships are essential for the provision of high quality care within psychiatric intensive care units. These relationships can be strengthened through staff training interventions, for example, the Safe & Secure programme. However, interventions delivered in psychiatric intensive care units are difficult to implement and sustain. Normalisation Process Theory offers a framework through which to measure how effectively new interventions are implemented in this setting.Methods: The aim of the study was to assess the implementation of a ward-based team training programme within a psychiatric intensive care unit. Following the delivery of the Safe & Secure ward-based team training programme, staff were interviewed about their experience and completed a quantitative measure of normalisation, the NoMAD. Interviews were analysed using reflexive thematic analysis with codes being grouped under the four constructs of Normalisation Process Theory.Results: Staff reported being able to recognise the utility of the intervention and, qualitatively, reported seeing it as beneficial for their clinical practice. NoMAD scores were high, indicating the normalisation of the intervention. However, staff found it difficult to quantify how the intervention had improved their practice. They also reported difficulties with applying the intervention in certain circumstances. Staff expressed concerns about intervention sustainability.Conclusions: The Safe & Secure ward-based team training programme was implemented and normalised into routine practice. The study identified areas for improvement in future deliveries of the programme. The study also provided useful information to help inform the future implementation of ward-based team trainings in psychiatric intensive care units.<br/
The association between socioeconomic status and outcomes in critical illness:A national cohort study of emergency admissions to critical care units in Scotland 2010-2021
Get PDFBACKGROUND: Socioeconomic inequalities in chronic disease management and outcomes are well-established. Their association with critical illness management and outcomes is less clear. This study aimed to investigate the association between socioeconomic status and outcomes following emergency admission for critical illness.METHODS: Three Scotland-wide health databases were linked: the Scottish Intensive Care Society Audit Group database (critical care units); the Scottish Morbidity Record 01 (hospital admissions) and death certificates. A retrospective cohort study was conducted on adults (⩾16 years) admitted as an emergency to critical care units between 25th October 2010 and 25th October 2021 inclusive. Cox proportional hazards models were used to investigate the association between area-based socioeconomic status (Scottish Index of Mortality (SIMD) decile) and all-cause mortality, adjusting for potential confounders: age, sex, comorbidities, illness severity, and diagnostic group. Secondary outcomes included unit and hospital lengths of stay, and emergency hospital readmissions.RESULTS: Overall, 50,914 patients were included in the cohort. Those in the least deprived decile were less likely to die ( adjHR 0.85, 95% CI 0.79-0.92), had 19% longer critical care unit stays (95% CI 13-26) and a 12% longer hospital stays (95% CI 7%-18%). Over the subsequent year, the least deprived had significantly fewer emergency hospital re-admissions ( adjIRR 0.73; 95% CI 0.67-0.81). DISCUSSION: People living in the most deprived communities have worse outcomes following emergency admission to critical care; particularly in the longer term and reinforcing the need to address socioeconomic inequalities in healthcare access and outcomes.</p
The Seismogenic Thickness of Venus
Get PDFGrowing evidence that volcanism is currently ongoing on Venus suggests that the sister planet of the Earth may also be seismically active. Given the success of seismic measurements on Mars and the Moon to reveal the interior structure of these bodies, seismic investigations on Venus are a natural next step. The potential for seismic activity is closely linked to the thickness of the so-called seismogenic layer, that is, the region where rocks behave in a brittle manner and quakes can nucleate. On Earth, the seismogenic thickness is correlated with the thermal structure of the lithosphere, and is typically associated with the depth of the 600°C isotherm. Here, we combine geophysical constraints with thermal evolution models to estimate the thermal structure of Venus' lithosphere and determine the corresponding seismogenic thickness. Taking all estimates into account, our results show that the seismogenic thickness overall varies from 2 to 35 km. The lowest values are associated with areas that probably correspond to local thermal anomalies associated with magmatic processes. This interpretation is corroborated by geodynamic models, which show that intrusive magmatism can largely increase the temperature within the lithosphere at local scales. The seismogenic layer is thickest at volcanic plains which are commonly associated with regions of mantle downwellings. In these regions, the seismogenic layer likely reaches Venus' mantle, while in areas with a thick crust or anomalously high thermal gradients, quakes might be limited to the crust. Our study provides evidence that Venus has a substantial seismic potential
Inherited chromosomally integrated human herpesvirus 6: regional variation in prevalence, association with angina, and identification of ancestral viral lineages in two large UK studies
Get PDFTens of millions of people worldwide have inherited chromosomally integrated human herpesvirus 6 (iciHHV-6), yet we know little about the consequences. iciHHV-6-positive individuals inherit the genome of HHV-6A or HHV-6B in the germline, and viral genomes are therefore present in every nucleated cell. To investigate the epidemiology of iciHHV-6 in the UK, almost 32,000 individuals were screened from two volunteer research studies: the family-based Generation Scotland: Scottish Family Health Study (GS:SFHS) and the Breakthrough Generations Study (BGS). iciHHV-6 prevalence in GS:SFHS was, to our knowledge, higher than that in other large studies at 2.74% (647/23,637), with an iciHHV-6B prevalence of 2.55%. Scottish participants were more likely to be iciHHV-6B-positive than English (P < 0.001), and the BGS results suggested a north-south gradient of iciHHV-6B prevalence in mainland Britain. Disease association analysis confirmed the previously reported association with angina, with an odds ratio of 1.91 (95% confidence interval, 1.29, 2.82) following adjustment for known risk factors, providing compelling evidence that iciHHV-6 contributes to the risk of a common symptom. De novo integrations were not detected within GS:SFHS pedigrees; rather, our findings indicated that three viral lineages accounted for over 95% of iciHHV-6A-positive samples, and six viral lineages accounted for 90% of iciHHV-6B-positive samples in GS:SFHS. This study demonstrates that iciHHV-6 is common in the UK, shows significant regional heterogeneity in prevalence, is not entirely harmless, and is largely derived from a relatively small number of ancestral viral lineages.IMPORTANCEHuman herpesvirus 6 (HHV-6) has the unusual ability to integrate into the host chromosome telomeres. Most of the world's population is infected by HHV-6 in early childhood, but around 1% inherit the virus as a chromosomally integrated viral genome-referred to as inherited chromosomally integrated HHV-6 (iciHHV-6). Little is known about the consequences of iciHHV-6, which has the potential to cause disease through various mechanisms. Here, we have used large cohorts to study iciHHV-6 prevalence, lineages, and phenotypic associations. We replicate a previously reported association between iciHHV-6 and angina, suggesting that iciHHV-6 is not entirely benign. We show significant variation in iciHHV-6 prevalence within the UK with almost 3% of Scottish people carrying iciHHV-6. In the first detailed analysis of viral lineages at the population level, we show that 90% of iciHHV-6 is explained by nine ancestral viral lineages. These results have important implications for future disease association analyses
Science as divine signs:Al-Sanūsī’s framework of legal (sharʿī), nomic (ʿādī), and rational (ʿaqlī) judgements
Get PDFThis article examines the Ashʿarī theological framework of Imam Abū ʿAbd Allāh Muḥammad ibn Yūsuf al-Sanūsī (d. 1490) and its potential for shaping contemporary Muslim engagement with science. At the heart of al-Sanūsī’s thought is a tripartite typology of judgements—legal (ḥukm sharʿī), nomic (ḥukm ʿādī), and rational (ḥukm ʿaqlī)—as articulated in The Preliminaries of Theology (al-Muqaddimāt). This classification distinguishes between rulings grounded in revelation, patterns observed in nature, and conclusions drawn from reason. Unlike other theological approaches, al-Sanūsī’s model integrates core Ashʿarī doctrines such as radical contingency, occasionalism, and divine command theory, offering a coherent synthesis of metaphysics, empirical inquiry, and ethics. Building on recent scholarship that re-engages with Ashʿarī theology in the context of Islam and science, this article argues that al-Sanūsī’s schema offers a meta-framework—one that positions science not merely as an object of analysis but as a locus for theology.</p
Geostatistical modelling of soil-transmitted helminth prevalence in Kenya: Informing targeted interventions to accelerate elimination efforts
Get PDFObjectives This study estimates the prevalence of soil-transmitted helminths (STH) in Kenya, identifying high- and low-burden communities to optimize intervention strategies. Methods Using prevalence data from 146,668 children in 3752 schools across 207 sub-counties in Kenya, collected in 2021 and 2024, alongside environmental and socio-economic data, we modelled the prevalence of hookworm, Ascaris lumbricoides and Trichuris trichiura at a 5 × 5 km resolution. We estimated the probability of exceeding predefined prevalence thresholds (2%, 10% and 20%) and the population-weighted mean prevalence for each species. Results Hookworm prevalence was low (mean of 0.6%, 95% credible interval [CI] 0.1%-2.9%), with 6% of sub-counties, primarily in coastal regions, exceeding the 2% threshold. T. trichiura prevalence was higher (mean 1.4%, 95% CI 0.2%-7.3%), with elevated risk in southwestern and coastal regions. A. lumbricoides was highest (mean 2.8%, 95% CI 0.1%-11.6%), clustering in western Kenya. Across all species, the probability of exceeding the 20% prevalence threshold remained below 0.5. Conclusion These findings underscore persistent STH transmission in some regions, necessitating region-specific treatment approaches, including strategic decisions on drug selection, target populations and optimized treatment frequency to achieve Kenya’s STH elimination targets
A Fisher-Rao Gradient Flow For Entropy-regularised Markov Decision Processes In Polish Spaces
Get PDFWe study the global convergence of a Fisher–Rao policy gradient flow for infinite-horizon entropy-regularised Markov decision processes with Polish state and action spaces. The flow is a continuous-time analogue of a policy mirror descent method. We establish the global well-posedness of the gradient flow and demonstrate its exponential convergence to the optimal policy. Moreover, we prove the flow is stable with respect to gradient evaluation, offering insights into the performance of a natural policy gradient flow with log-linear policy parameterisation. To overcome challenges stemming from the lack of the convexity of the objective function and the discontinuity arising from the entropy regulariser, we leverage the performance difference lemma and the duality relationship between the gradient and mirror descent flows. Our analysis provides a theoretical foundation for developing various discrete policy gradient algorithms.</p
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