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Species functional traits affect regional and local dominance across western Amazonian forests
Get PDF1. Several studies have documented dominance by few species in Amazonian forests. Dominant species tend to be either locally abundant (local dominants) or regionally frequent (widespread dominants) but rarely both (oligarchs). Here, we explore relationships between dominance and functional traits. We ask whether: (i) dominance is associated with specific functional profiles and (ii) dominance patterns (local vs. widespread dominants) are associated with different functional traits.
2. We combined census data from 503 forest inventory plots across four lowland forest habitats in western Amazonia with trait information for ~2600 tree species, encompassing data collected in the focal plots and data from published sources. We considered traits that relate to leaf, wood, seed and whole-plant strategies: specific leaf area (SLA), leaf area (LA), N content per unit leaf mass (LN), wood density (WD), seed mass (SM) and maximum diameter at breast height (DBHmax).
3. Our results reveal that dominant species display different trait combinations depending on the habitat type. Taller dominant species exhibit higher regional frequency, associated with higher dispersal ability and lower local abundance, likely due to negative density dependence. Greater SM contributes to higher regional frequency of dominant species via greater dispersal by birds and mammals and seedling survival. Finally, traits related to resource conservation strategies, such as lower SLA, LA, LN and greater WD, favour higher local densities across most habitats, while the opposite pattern was linked to higher regional frequency.
4. Synthesis. Our findings reveal that (i) dominance is associated with different functional traits depending on the habitat type, and (ii) different functional trait values define distinct dominance patterns. Our study exemplifies the potential of trait-based approaches to illuminate the ecological mechanisms that may underlie dominance in tropical forests. Finally, accounting for both local abundance and regional frequency when studying dominance is likely to improve our understanding and forecasting of how different species will respond to global change drivers in western Amazonia
Derivation of a South African tariff for the EQ-5D-5L using a personal utility function approach
Get PDFObjectives
This study’s primary objective was to test the feasibility of using the online personal utility function (OPUF) approach and develop a preliminary utility tariff for the EQ-5D-5L based on a South African community sample.
Methods
The need for an ethnically and socioeconomically diverse sample was seen as essential. This led to the need for interviewer assistance during completion of the survey instrument and translation of the instrument into multiple languages. English, Zulu, Tswana, and Afrikaans were chosen to allow the vast majority of a community sample people to participate. A sample size of sixty respondents was based on a previous OPUF pilot valuation study for the EQ-5D-5L, and a pilot study of twenty respondents was undertaken using the English language version of OPUF.
Results
There were sixty-one respondents in the main study with most respondent characteristics being well matched with national figures, except for language. Personal utility functions could be calculated for sixty respondents, with the mean tariff showing monotonically declining utility decrements within each dimension. An examination of individual functions showed two contrasting sets of preferences that were driven by the respondents’ rating of death. A separate subgroup analysis also showed preference heterogeneity based on the home language of the respondents.
Conclusions
Our study showed that the application of the OPUF approach is possible in a socioeconomically diverse population in South Africa. The examination of individual personal utility functions shows marked heterogeneity of preferences that needs to be explored further so that the source of this can be established
Proximity labeling of DAF-16 FOXO highlights aging regulatory proteins
Get PDFInsulin/insulin-like growth factor signaling inhibits FOXO transcription factors to control development, homeostasis, and aging. Here, we use proximity labeling to identify proteins interacting with the C. elegans FOXO DAF-16. We show that in well-fed, unstressed animals harboring active insulin signaling, DAF-16 forms a complex with the PAR-1/MARK serine/threonine kinase, a key regulator of cell polarity. PAR-1 inhibits DAF-16 accumulation and promotes DAF-16 phosphorylation at S249, at a conserved motif that PAR-1/human MARK2 phosphorylates in vitro. DAF-2 insulin-like receptor signaling stimulates DAF-16 S249 phosphorylation, suggesting DAF-2 activates PAR-1. DAF-2 also promotes PAR-1 expression by inhibiting DAF-16. PAR-1 knockdown, or DAF-16 S249A, prolong lifespan, whereas phosphomimetic DAF-16 S249D suppresses the longevity of daf-2 mutants. At low insulin signaling, DAF-16 proximity labeling highlights transcription factors, chromatin regulators, and DNA repair proteins. One interactor, the zinc finger/homeobox protein ZFH-2/ZFHX3, forms a complex with DAF-16 and prolongs lifespan. Our work provides entry points for hypothesis-driven studies of FOXO function and longevity
Comparative Analysis of Global Standards in Accelerated Carbonation Testing of Concrete
Get PDFCarbonation is one of the major causes of steel reinforcement corrosion, affecting the durability of concrete. Natural carbonation is a very long process; therefore, to predict the development of concrete carbonation, standards prescribe accelerated carbonation tests, in which specimens are exposed to carbon dioxide (CO₂) in a controlled environment. Although based on the same principle, global standards differ in methodology, e.g., different CO₂ concentrations, relative humidity or size of the specimens. Results of these tests might not be comparable with each other, and therefore, it is difficult to conclude which methodology most accurately predicts long-term carbonation. This diversity in standards highlights the need to study and compare them to identify similarities, differences, and the reasons behind these variations in accelerated carbonation tests worldwide. In this study, 12 standards from various regions were examined for differences in key parameters. Significant variations were found, largely due to climatic differences and testing objectives. A correlation was observed between CO₂ concentration and specimen surface area, and the study also noted that standards specifying higher CO₂ concentrations tend to have shorter test durations compared to those with lower CO₂ concentrations, aiming to accelerate the testing process. The study found that the ISO standard is applicable
across diverse climatic conditions, as its flexible temperature and humidity ranges allow adjustment to local environments within the ISO limits
Trimodal age distribution of frequent attendance at the emergency department: a descriptive analysis of national, English, secondary care data using a retrospective cohort
Get PDFObjectives
Frequent use of emergency departments (EDs) places a considerable burden on healthcare systems. Although frequent attenders are known to have complex physical, mental health and social needs, national-level evidence on their characteristics and patterns of attendance remains limited. This study aimed to provide a comprehensive, population-level description of frequent ED attendance in England, with a focus on age-based subgroups.
Design
Retrospective cohort study.
Setting
EDs in England via the Hospital Episode Statistics and the Emergency Care Dataset data linked with primary care prescribing and mortality data, between March 2016 and March 2021.
Participants
The dataset received from National Health Service Digital contained approximately 150 million ED attendances by 30 million adult (>18 years) patients over the time period April 2016 to March 2021. A random sample of 5 million people was used for this analysis.
Outcome measures
The primary outcome was the number of attendances in each financial year by frequent attenders compared with the remaining patients, split by age bands. Patients were classified as frequent attenders if they had ≥5 or ≥10 ED attendances within a rolling 12-month period. Secondary outcomes included demographic, diagnostic and prescribing characteristics, as well as the number of different ED sites visited.
Results
A Gaussian mixture model was used to identify age-based subgroups. Descriptive statistics were used to summarise key features; 95% CIs were reported where applicable. Among 3.91 million unique adult ED attenders, there were 8.7 million attendances. Of these, 222 160 individuals (5.7%) had ≥5 attendances in a year, accounting for 12.6% of total attendances. A trimodal age distribution was identified, with three distinct peaks corresponding to ages 18–34, 35–64 and 65+. Frequent attenders were more likely to live in deprived areas and have a history of psychotropic or analgesic prescribing. Mental health diagnoses and polypharmacy were particularly common in the younger and middle-aged groups. Multisite attendance was uncommon, with over 80% of frequent attenders using only one ED site annually.
Conclusions
This national analysis reveals a trimodal age pattern among frequent ED attenders, with differing clinical and socio-demographic profiles across age groups. These findings highlight the need for age-tailored approaches to managing high-intensity ED use and inform targeted service development
Violence reduction in a changing European urban context: Frontline practitioner’s understanding of the roots of violence, and why it matters for policy and prevention
Get PDFViolence continues to be a concern for policymakers and communities, notably so in urban contexts in which socio-demographic change, retrenched social support and evolving forms of exclusion affect its distribution and intensity. Drawing from a comparative qualitative study in European cities, we analyse the narratives and explanations offered by key stakeholders, civic and policy actors working at the interface of violence prevention and urban communities. Informed by scholarship on street-level bureaucracy and local knowledge, we find in their accounts key operating theories that connect the risk of violence with austerity conditions and their erosion of vital social and institutional fabrics, thereby worsening localised violence in these ‘ordinary’ cities. We conclude that there is a significant disconnect between the subtle and informed accounts of local, civic actors and the drift to further disinvestment in cities and social institutions being delivered by central political institutions. Local practitioners understand violence to be linked to these macro-economic conditions and social inequalities that sit outside their jurisdiction, but which ultimately present major challenges to the fabric of local urban life and risks to particular communities
Relative security: (dis)proving resilience against semantic optimization vulnerabilities in Isabelle/HOL
Get PDFMeltdown and Spectre are vulnerabilities known as transient execution vulnerabilities, where an attacker exploits speculative execution (a semantic optimization present in most modern processors) to break confidentiality. We introduce relative security, a general notion of information-flow security that models this type of vulnerability by contrasting the leaks that are possible in a “vanilla” semantics with those possible in a different semantics, often obtained from the vanilla semantics via some optimizations. We describe incremental proof methods, in the style of Goguen and Meseguer’s unwinding, both for proving and for disproving relative security, and deploy these to formally establish the relative (in)security of some standard Spectre examples. Both the abstract results and the case studies have been mechanized in the Isabelle/HOL theorem prover. This paper is an extension of an earlier conference paper that provides significantly more detail on the Isabelle formalization and the unwinding proof process
Brain pulsations enhance cerebrospinal fluid flow in perivascular spaces
Get PDFCerebrospinal fluid (CSF) flow is modelled in human perivascular spaces (PVSs) that surround brain penetrating arteries. It is proposed that the outer PVS boundary oscillates due to brain pulsations, and the arterial wall motion is driven by a blood pressure wave. Lubrication theory is employed to derive a mathematical model for the CSF flow, which is then solved numerically. A parametric analysis is undertaken to investigate the effect of the brain pulsations, which shows that pulsations magnify the net axial CSF flows created by the arterial wall motion. The findings suggest that net axial CSF flows are almost entirely positive (deeper into the brain), with arterial wall motion highly dependent on PVS-penetrating artery configurations. Given the glymphatic hypothesis, the findings support the clinical practice of treating dilated PVSs as indicators of an increased likelihood of neurodegenerative conditions, such as dementia
Atopy, asthma symptoms and eosinophilic airway inflammation in British woodworkers
Get PDFObjectives
Despite reducing exposures to wood dust, woodworkers remain at increased risk of asthma. There have been no recent studies of wood dust exposure, respiratory symptoms or asthma in British woodworkers. This cross-sectional study examined factors associated with asthma in British woodworkers across exposure groups.
Methods
Participants answered a reporter-delivered work and respiratory questionnaire, and underwent fractional exhaled nitric oxide (FENO), spirometry and specific IgE measurements. Wood dust exposure was assigned through a job-exposure matrix. Multiple regression evaluated associations between asthma and factors including exposure, atopy and current asthma symptoms (CAS).
Results
A total of 269 woodworkers participated. Median wood dust exposure was 2.00 mg/m3 (IQR 1.14 mg/m3). CAS, work-related respiratory symptoms (WRRS) and eosinophilic airway inflammation (FENO>40 ppb) were common, present in 46%, 11% and 19% of the cohort, respectively. Atopic woodworkers were more likely to have nasal symptoms (OR 2.13, 95% CI 1.18 to 3.85, p40 ppb (OR 2.00, 95% CI 1.03 to 3.88, p40 ppb or airflow obstruction. A dose-response effect with wood dust exposure was not seen.
Conclusions
Asthma symptoms were prevalent among British woodworkers, even at low exposure levels. Atopy was associated with asthma, particularly among symptomatic woodworkers. Further studies should phenotype woodworkers at risk of asthma and inform approaches to reduce risk
Incidence of developmental disorders and special educational needs and disabilities in children in the UK
Get PDFAim To investigate the incidence of developmental disorders (including cerebral palsy, attention-deficit/hyperactivity disorder, and autism spectrum disorder) and special educational needs provision and to explore associations with gestational age and ethnicity. Method Cumulative incidence of developmental disorders and special educational needs provision up to age 12 years/end of school year 7 respectively was explored using multivariable logistic regression in the Born in Bradford cohort, UK. Incidence rates of individual developmental disorders were calculated. Results There were 13 172 children included in the analysis cohort. Birth before full term was associated with increased odds of developmental disorder compared with birth at full term: adjusted odds ratio (aOR) for those born before 34 weeks 2.22 (95% confidence interval [CI] 1.58–3.12); 34 to 36 weeks aOR 1.43 (95% CI 1.12–1.81); 37 to 38 weeks aOR 1.18 (95% CI 1.03–1.34). Effect sizes were larger among Pakistani heritage children: aOR for those born before 34 weeks 2.59 (95% CI 1.55–4.33); 34 to 36 weeks aOR 1.57 (95% CI 1.08–2.27); 37 to 38 weeks aOR 1.29 (95% CI 1.06–1.56). Unadjusted incidence rates of developmental disorders varied with ethnicity; compared with Pakistani heritage children, White British children had higher rates (per 1000 person-years) of attention-deficit/hyperactivity disorder (1.8, 95% CI 1.5–2.1 vs. 0.3, 95% CI 0.2–0.4), and lower incidences of learning disabilities (0.7, 95% CI 0.5–1.0 vs. 1.6, 95% CI 1.4–1.9). Interpretation Irrespective of ethnicity, children born before full term are at increased risk of developmental disorders and/or special educational needs
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