Biodiversity of beetles: The phylogenetic composition of beetle communities across tropical forests of the world

This thesis examines the phylogenetic diversity patterns of beetle (Coleoptera) communities across tropical forests by developing and implementing molecular methodologies. A novel protocol for authenticating amplicon sequence variants was designed using 10,395 specimens representing 98 families from 11 countries, integrating abundance-based filtering with phylogenetic placement to achieve an authentication success rate of 82.34%. Multivariate analysis identified preservation methodology (χ² = 145.00, p < 0.001) and sequencing protocols (χ² = 287.45, p < 0.001) as primary determinants of authentication outcomes. Machine learning frameworks were implemented to automate sequence authentication, with DNA barcoding and metabarcoding pipelines achieving an accuracy of 99.80%. Field applications in Thailand's protected areas yielded 1,800 specimens (71 families) processed via mitogenomics (187 mitogenomes), DNA barcoding (584 sequences), and metabarcoding (608 operational taxonomic units, or OTUs). Phylogenetic analysis revealed that Thai specimens (1.54% of the global dataset) contributed disproportionately to total phylogenetic diversity (3.23%, p<0.01). Community structure analysis revealed significant phylogenetic clustering at Khao Yai National Park (NRI = 1.875207, p < 0.001) and overdispersion at Sakaerat Environmental Research Station (NRI =-0.82255, p < 0.01). Comprehensive phylogenetic analysis integrated 12,320 mitochondrial genome sequences, establishing sequential infraorder diversification in Polyphaga spanning approximately 56 million years (254.3-198.5 Ma). The lineages-through-time analysis identified an inflexion point at approximately 120 MYA, coinciding with angiosperm radiation. This research advances the understanding of beetle diversity while establishing methodological frameworks for molecular biodiversity assessment in hyperdiverse taxa.Open Acces

Parallelisation of partial differential equations via representation theory

Incorporating symmetries into the numerical solution of differential equations has been a mainstay of research over the last 40 years, however, one aspect is less known and under-utilised: discretisations of partial differential equations that commute with symmetry actions (like rotations, reflections or permutations) can be decoupled into independent systems solvable in parallel by incorporating knowledge from representation theory. We introduce this beautiful subject via a crash course in representation theory focussed on hands-on examples for the symmetry groups of the square and cube, and its utilisation in the construction of so-called symmetry-adapted bases. Schur’s lemma, which is not well-known in applied mathematics, plays a powerful role in proving sparsity of resulting discretisations and thereby showing that partial differential equations do indeed decouple. Using Schr¨odinger equations as a motivating example, we demonstrate that a symmetry-adapted basis leads to a significant increase in the number of independent linear systems. Counterintuitively, the effectiveness of this approach is in fact greater for partial differential equations with less symmetries, for example a Schr¨odinger equation where the potential is only invariant under permutations, but not under rotations or reflections. We also explore this phenomenon as the dimension of the partial differential equation becomes large, hinting at the potential for significant savings in high-dimensions

Preservation of the human ovary

Study 1a assessed oncological safety of fertility-sparing surgery (FSS) in 172 women with borderline ovarian tumours (BOTs). FSS was performed in 52.3% of cases and associated with higher recurrence than non-FSS (25.6% vs 7.7%). However, no invasive recurrences occurred following FSS, whereas all recurrences after radical surgery were invasive low-grade serous carcinomas. Ultrasound-guided ovarian wedge resection (UGOWR) was introduced as a novel FSS technique, showing comparable recurrence rates to established approaches, with postoperative ultrasound surveillance enabling early detection. Study 1b compared BOT recurrence in women pursuing spontaneous pregnancy (SP) or fertility treatment (FT) following FSS versus non-exposed women. Recurrence risk did not differ significantly overall (22.2% vs 20%). While FT combined with successful SP was associated with increased recurrence risk, all recurrences were non-invasive, supporting the oncological safety of fertility treatment. Study 2 surveyed 415 UK healthcare professionals and identified major deficits in fertility preservation (FP) education: 87% had no formal training, 39.5% never discussed FP with patients, and over half lacked counselling confidence, demonstrating system-wide barriers to effective FP provision. Study 3’s randomized trial comparing laparoscopic cystectomy with ultrasound-guided ovarian cystectomy (UGLOC) found no significant differences in postoperative ovarian reserve (AMH, AFC) at six months, though UGLOC resulted in less excised ovarian tissue, suggesting potential benefit for women with diminished baseline reserve. Study 4a surveyed 5,482 UK women and revealed pervasive misinformation on fertility decline, miscarriage risk, elective oocyte cryopreservation (EOC) timing and costs. Study 4b evaluated outcomes from EOC cycles: live birth occurred in 26.8% of thaw cycles, with no livebirths demonstrated among women ≥40. Study 5a demonstrated that reduced ovarian reserve (low AMH/AFC) significantly increases miscarriage risk, particularly in women under 35. Study 5b found that blastocyst PGT-A modestly improves live birth and implantation rates while reducing miscarriage compared with morphology alone, although further validation is required.Open Acces

Mortality in children with fulminant myocarditis: a six-year multicenter retrospective study

Background Fulminant myocarditis (FM) in children can progress rapidly to cardiogenic shock, with high risk of mortality. Early recognition of prognostic markers is critical to guide timely escalation of circulatory support. This multicenter study sought to characterize clinical features and identify early predictors of in-hospital mortality in pediatric FM. Methods We conducted a retrospective cohort study of patients <18 years with FM admitted to eight ECMO-capable pediatric intensive care units between January 2018 and August 2023. Clinical, biochemical, electrocardiographic, and echocardiographic variables were analyzed. Logistic regression was used to identify predictors of mortality, and receiver operating characteristic (ROC) curves were generated to assess discriminatory performance. Results A total of 187 children were included; 157 (84.0%) required ECMO. In-hospital mortality was 16.6% (31/187). Univariate analysis identified elevated CK-MB, higher peak lactate, and ventricular tachycardia as associated with mortality. In multivariate analysis, peak lactate (AUC 0.791) and CK-MB (AUC 0.774) remained independent predictors. A combined model of peak lactate and ventricular tachycardia demonstrated moderate discrimination (AUC 0.772), whereas a composite model incorporating CK-MB, peak lactate, and ventricular tachycardia achieved the best predictive performance (AUC 0.815). Elevated lactate measured 12 h after initiation of extracorporeal membrane oxygenation or intensive conventional therapy further increased mortality risk (OR 1.219, 95% CI 1.004–1.481). Conclusion Peak lactate, CK-MB, and ventricular tachycardia are early independent predictors of in-hospital mortality in pediatric FM. Persistent hyperlactatemia within 12 h of advanced support provides additional prognostic value and may assist clinicians in early risk stratification

Renewal theory for Brownian motion with stochastically gated targets

There are a wide range of first passage time (FPT) problems in the physical and life sciences that can be modelled in terms of a Brownian particle binding to a reactive target surface and initiating a downstream event (absorption). However, prior to absorption, the particle may undergo several rounds of surface attachment (adsorption), detachment (desorption) and diffusion. That is, the surface is effectively ‘sticky’. Alternatively, the surface may be stochastically gated so that absorption can only occur when the gate is open. In both cases one can view each attachment to the surface as a renewal event. In this paper we develop a renewal theory for stochastically gated target problems along analogous lines to previous work on sticky targets. We proceed by constructing a first renewal equation that relates the joint probability density for particle position and the state of a gate to the probability density and FPT density for a totally absorbing (non-gated) boundary. This essentially decomposes sample paths into an alternating sequence of bulk diffusion and instantaneous adsorption/desorption events, which is terminated when adsorption coincides with an open gate. In order to ensure that diffusion restarts in a state that avoids immediate re-adsorption, we assume that whenever the particle reaches a closed boundary it is instantan eously shifted a distance ϵ from the boundary (desorption-induced resetting). We explicitly solve the renewal equation in the one-dimensional case and show how the solution to the original gated FPT problem is recovered in the limit ϵ → 0. We then calculate the MFPT for absorption (assuming it exists) and determine its dependence on ϵ and the switching rate of the gate. We also show how spectral methods can be used to solve the renewal equation in higher spatial dimensions. We thus establish renewal theory as a general mathematical framework for modelling both sticky and stochastically gated targets

What’s the point? How users functionalise points in gamified systems

Points are widely used design elements in gamified systems. Yet how they motivate is still unclear: what motivational meaning or functional significance do users ascribe to points and when? To answer this question, we conducted a semi-structured interview study with 27 users of two popular gamified platforms, Duolingo and Habitica. Through reflexive thematic analysis, we constructed six different types of functionalisation variously proposed in prior gamification and personal informatics work but often not empirically supported. We highlight the importance of functional design detail (such as points should proportionally reward effort) and derive design guidelines

Hydraulic endorectal actuator for prostate radiotherapy reduces variations in motion in a silicone rectal phantom

Background: The accuracy and morbidity of prostate cancer radiotherapy are influenced by unpredictable variations in rectal filling and patient motion. We developed a soft robotic hydraulic endorectal actuator that aims to reduce rectal motion and retract the rectum to restore the anorectal angle, improve target accuracy, and reduce toxicity during prostate cancer radiotherapy. The ability of the endorectal actuator to stabilize the rectum and improve prostate radiotherapy outcomes has not yet been assessed. This study evaluates the actuator’s performance in a simulated rectal phantom. Methods: We fabricated a rectal phantom using silicone and motor-controlled elastic ribbons to simulate muscle tone and control the phantom diameter. The rectal compliance of the phantom was validated using a barostat balloon and was deliberately set low to simulate a high resistance to distension to challenge the actuator’s capabilities. We assessed the actuator’s ability to (1) resist dynamic peristaltic forces and (2) reproduce the rectal position and anorectal angle from varying initial displacements. The anterior–posterior rectal diameter and anterior rectal wall (ARW) displacements were measured using video tracker software. Results: The phantom demonstrated a rectal compliance of 4.19 ml/mmHg within the 40 ml–60 ml volume range, meeting the low-compliance target. During dynamic compression, the endorectal actuator reduced the change in the anterior–posterior diameter and ARW displacement from 25 mm and 15 mm, respectively, to less than 5 mm in both. The actuator reduced the increase in rectal volume from 132.3 cm3 (control) to 59.7 cm3 (actuator). When the phantom was translated anteriorly, the actuator reduced the anorectal angle deviation from +12° to +2° and anterior displacement of the ARW from 13 mm to 4 mm. Conclusion: Within this rectal phantom, the endorectal actuator reduced the variations in rectal motion. These findings suggest that the actuator may improve target accuracy and reduce radiation-induced toxicity in prostate radiotherapy, pending in vivo validation of the results

Outcomes in children with enterovirus meningitis in London, England: a retrospective multicentre cohort study, 2013 - 2023

Non-polio enteroviruses (EV) are the most common cause of meningitis in children. We conducted a retrospective case series of long-term outcomes in 243 children between 1/1/2013 and 31/12/2023 across four tertiary centres in London. Adverse outcomes were associated with absence of fever at presentation (odds ratio, OR 4.65, 95% CI 1.03, 20.83), presence of seizures (OR 7.40, 95% CI 1.05, 51.96) and presence of comorbidities at baseline (OR 5.27, 95% CI 1.18, 23.47). Full recovery was seen in 153/160 (95.6%) of children who were under 3 months of age. These data may help clinicians to counsel parents and policymakers on streamlining care pathways following hospital discharge

Obesity, metabolic health status, and adverse outcomes in men and women

Background Metabolically healthy obesity account for approximately one-third of individuals with obesity and could affect up to 300million individuals worldwide. Whether this is a truly benign cardiometabolic phenotype as the name suggests is incompletely defined, leading to uncertainty regarding the optimal risk stratification and management strategies for these individuals. Objectives To assess the sex-specific independent and joint associations of obesity and metabolic health status on cardiometabolic outcomes and death. Methods A prospective cohort study of UK Biobank participants free from cardiovascular diseases and not underweight. Participants were divided by BMI into normal, overweight or obese, and the presence or absence of ≥1metabolic abnormality (hypertension, diabetes or dyslipidaemia). Exposures were assessed at baseline(2006-2010), with outcomes ascertained over a median follow-up of 12.9 years(IQR 12.6-13.3). Sex-specific outcomes were fatal or non-fatal atherosclerotic cardiovascular disease(ASCVD; a composite of coronary heart disease, ischaemic stroke, and peripheral artery disease), heart failure(HF), metabolic dysfunction-associated steatotic liver disease(MASLD), end-stage renal disease(ESRD) and all-cause mortality. Multivariable-adjusted cox regression models were used to estimate hazard ratio (HR) and 95%CI. Results Among 157,159 participants (mean age 56.5years [SD 8.2]; 55.6% women), 24.2% were obese and 68.2% had ≥1 metabolic abnormality. Compared to normal BMI and no metabolic abnormality (reference group), obesity was associated with increased risk of ASCVD(HR 1.46, 95%CI 1.24-1.73), HF(1.63,1.14-2.32), MASLD(2.37,1.22-4.61), all-cause mortality(1.36,1.10-1.69) but not ESRD in men without metabolic abnormalities, which increased when any metabolic abnormality was present: ASCVD(2.21,2.03-2.41), HF(2.91,2.41-3.50), MASLD(6.84,4.60-10.18), ESRD(5.42,2.94-10.02), and all-cause mortality(1.62,1.45-1.81). Corresponding risk from obesity in women without metabolic abnormalities were: ASCVD(1.34,1.14-1.58), HF(1.69,1.21-2.37), MASLD(4.44,3.00-6.59), and all-cause mortality(1.27,1.05-1.52) but not ESRD, which increased when metabolic abnormalities were present: ASCVD(2.51,2.30-2.74), HF(3.67,3.04-4.43), MASLD(8.17,6.13-10.89), ESRD(7.96,4.00-15.85) and all-cause mortality(1.67,1.51-1.85). Adverse outcomes increased with severity of obesity, the presence of central obesity, and with increasing numbers of metabolic abnormalities, with an effect modification by sex suggesting more harm from obesity, central obesity and metabolic abnormalities in women. Conclusions Obesity without metabolic abnormalities is not benign and associated with multiple adverse cardiometabolic outcomes, further exacerbated when metabolic abnormalities occur. As 300million individuals may be considered metabolically healthy but obese, future studies should explore whether preventing or reversing obesity prior to the appearance of significant metabolic abnormalities results in improved health outcomes