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Global and regional drivers for exceptional climate extremes in 2023-2024: beyond the new normal
Get PDFClimate records have been broken with alarming regularity in recent years, but the events of 2023–2024 were exceptional even when accounting for recent climatic trends. Here we quantify these events across multiple variables and show how excess energy accumulation in the Earth system drove the exceptional conditions. Key factors were the positive decadal trend in Earth’s Energy Imbalance (EEI), persistent La Niña conditions beginning in 2020, and the switch to El Niño in 2023. Between 2022 and 2023, the heating from EEI was over 75% larger than during the onset of similar recent El Niño events. We show further how regional processes shaped distinct patterns of record-breaking sea surface temperatures in individual ocean basins. If the recent trend in EEI is maintained, we argue that natural fluctuations such as ENSO cycles will increasingly lead to amplified, record-breaking impacts, with 2023–2024 serving as a glimpse of future climate extremes
The vocabulary challenge of the English Language GCSE Exam and the implications for adolescent reading experience
Get PDFA new English language GCSE exam in England has put an increased focus on
adolescents’ comprehension of unseen literary texts, from all three of the 19th, 20th and 21st
centuries. Since reading experience is a strong predictor of successful reading
comprehension, it is important to know whether what adolescents read prepares them for this
new exam. Any findings related to this particular exam could also have broader implications
for other assessment jurisdictions and for theory. This PhD project focuses on: 1) the
vocabulary challenge presented by the new exam texts; 2) the type of reading material that
provides experience with this vocabulary; and 3) the actual reading experience of
adolescents, including the vocabulary they encounter. First, a corpus of exam texts was
created and analysed to examine typical vocabulary (Paper 1). Next, a survey reported
respondents’ attainment in the English language GCSE exam and their reading experience
(Paper 2). Finally, two further corpora, created from samples of students’ independent and
curriculum reading materials, were analysed (Paper 3). The keywords in the exam texts were
found to be typically low frequency and most likely to be encountered in older, literary texts.
The reading survey showed that students who gained high grades also had more exposure to
classic authors. The final corpus analysis showed that students’ independent reading for
pleasure was a better match for the exam texts than their curriculum reading, although the
vocabulary in the curriculum reading was more challenging. This study contributes new
primary data in the three new corpora and in the data on adolescent reading habits from the
survey. It shows that reading experience can be analysed and explored through the use of
corpus linguistics and through a genre-specific ART. Finally, a potential influence of
assessment content on curriculum choices and on reading practices is identified
Small-angle scattering studies on diverse peptide-based nanotube and helical ribbon structures reveal distinct form and structure factors
Get PDFPeptide-based nanotubes are bio-based self-assembled nanostructures with intriguing structural and functional properties. The structure of such nanotubes can be probed in detail using small-angle scattering experiments due to the typical length scales, i.e. diameter and wall thickness of the nanotubes, which span the range accessible in small-angle X-ray scattering (SAXS) or small-angle neutron scattering (SANS) studies. Here, we present SAXS data for several classes of peptide and lipopeptide systems previously studied by our group, as well as newly reported data for model short lysine-sequence lipopeptides. Previous data are re-examined using more accurate models for data plotted on Kratky plots, which emphasizes fine details of nanotube structure. In some cases, consideration of structure-factor effects is necessary to allow for the coexisting structures, and a lamellar structure factor is used to describe this. In other cases, such as several examples of surfactant-like peptides, only a form factor has to be considered to accurately fit the measured SAXS data. In these cases, a form factor for hollow nanotubes with a Gaussian bilayer profile to represent the layered peptide ordering in the nanotube walls is used to model the data. A general expression for the cross section scattering form factor is provided, which can be used for any scattering density profile (electron density for SAXS or scattering length density for SANS) across the wall. This is analysed along with the form factor for multishell (multiwall) nanotube structures with a series of slabs to represent the scattering density profile. For lipopeptides C 16 -KFK and C 16 -K (C 16 indicates a hexadecyl lipid chain), SAXS data show aperiodicity in the form-factor oscillations, as well as apparent broad structure-factor peaks. These features cannot be fitted using solely nanotube form-factor models, this being ascribed to the presence of coexisting structures. Lastly, for comparison, the form factors for helical ribbon and cochleate (scroll) structures are evaluated for several examples, since in many cases electron microscopy of peptide- and lipopeptide-based nanotube systems reveals the coexistence of nanotubes with such structures, related to nanotubes
Quantifying the state-dependent causal effect of Barents-Kara sea ice loss on the stratospheric polar vortex in a large ensemble simulation
Get PDFThe Barents-Kara Sea ice concentration (BKS) has undergone dramatic declines in recent decades, consistent with the overall reduction in sea ice across the Arctic region. There has been a long-standing scientific question whether this BKS loss significantly influences winter temperature extremes over mid-to-high latitudes. While there is ongoing debate on this point, it is generally acknowledged that BKS loss affects the stratospheric polar vortex (SPV) through the enhancement of upward propagating waves, which itself can subsequently influence surface weather and climate conditions. However, due to the large internal variability within the climate system and the limited observational data, the strength of the BKS-SPV linkage and its dependence on different background states remain unclear. In this work, we investigate the causal effect of BKS change on SPV using a climate model with large ensemble simulations. Consistent with previous literature, the results indicate that BKS loss significantly weakens the SPV, with the magnitude of the response varying with El Niño‐Southern Oscillation (ENSO) and Quasi-Biennial Oscillation (QBO) phases, indicating a state-dependent causal effect. In particular, El Niño is found to suppress the causal effect of BKS change on the SPV, whereas La Niña and neutral ENSO strengthen it, which is consistent with what is found from observations. In contrast, the effect of QBO alone is relatively weak but becomes more pronounced when combined with ENSO. Dynamical analyses reveal that both tropospheric wave forcing and modulation of stratospheric wave propagation contribute to the state-dependent causal effects. By leveraging large ensemble simulations and combining statistical and physical analyses, this study provides an additional perspective on understanding the factors influencing the SPV response to BKS loss, which could ultimately impact surface climate
Exploring synergy: integrated indoor and outdoor air quality interventions for enhanced public health in London
No full textThis dissertation explores the intersection of both air quality improvement strategies and urban
morphology on health outcomes within diverse socioeconomic strata of London's population. This
work systematically reviews the methodologically diverse efficacy evidence of dual indoor and
outdoor combined interventions to reduce exposure to traffic-related air pollution concentration,
more particularly investigating the synergistic potential to improve health across different social
groups.
A multi-tier exposure model was employed to estimate PM2.5 concentrations across various
environments, including indoor spaces, transportation, and outdoor areas. The results show a
significant reduction in PM2.5 exposure when considering indoor infiltration rates, with exposure
levels indoors being 45% lower than those experienced outdoors. However, exposure during transit,
particularly on the London Underground, was found to significantly elevate total exposure levels,
despite limited time spent in this environment.
The research also examined the effects of urban form on NO2 distribution, finding that urban design
interventions, such as optimising building heights and increasing tree canopy cover, can reduce NO2
concentrations by up to 7 μg/m³. Additionally, the analysis of air pollution levels during the COVID-19
lockdown period revealed substantial reductions in both PM2.5 and NO2 concentrations, particularly
benefiting lower socioeconomic groups due to reduced transportation activity.
Indoor air quality interventions, specifically the use of air purifiers, were shown to be highly effective
in reducing PM2.5 concentrations by over 45%, leading to the prevention of more than 1000 annual
mortalities. Continuous operation of air purifiers was found to be the most cost-effective strategy,
yielding net economic benefits of approximately £1.006 billion.
The study highlights the importance of considering both indoor and outdoor environments when
addressing urban air pollution. It also emphasizes the need for tailored interventions that account for
socioeconomic disparities, as more deprived areas tend to experience higher health benefits but also
greater variability in outcomes.
Overall, this dissertation provides robust evidence supporting the integration of indoor and outdoor
air quality management strategies to improve public health. It offers practical insights for
policymakers and urban planners, advocating for comprehensive, equitable, and cost-effective
approaches to reduce the health burden of urban air pollution
The nexus between biodiversity conservation and participatory development in Africa: a case of the Congo basin in Cameroon
No full textUsing participatory land-use planning as its lens and the Tri-National Dja-Odzala-Minkébé
(TRIDOM) conservation segment in Cameroon as its study area, this study explores how
conservation strategies and practices put in place as participatory approach objectives can
potentially, directly or indirectly, negatively impact socially and economically marginalised
people’s decision-making process to participate in the broader conservation of biodiversity
in the Congo Basin. The study used both qualitative and quantitative methodologies with GIS
mapping in carrying out the research. It focuses on three predominantly Bantu-Djem village
communities and two Indigenous Baka people communities (with a total of 171 respondents).
Both ethnic communities have been subjected to comparable forms of forest policy,
governance and power dynamics in the forest region, including the same community forest
regime, land rights, logging rights and access to forest resources. The findings reveal that the
origin of participatory approaches to biodiversity conservation in Cameroon did not start in
the 1970s but started before colonisation in the 1880s. At the time, participatory approaches
to nature conservation were applied by indigenes as a bottom-up participatory approach but
the participatory process was reversed to a top-down approach with colonisation that led to
increasing marginalisation of the local population. Ultimately, this rendered participation as
an instrument (largely an exercise) with only a few community voices that leveraged it to
ensure institutional continuity. Empirical evidence gathered demonstrates that community
participation in the participatory land use planning process, through community forests
management, was largely nominal. The use of participation to achieve government aims
emerged from the process, which was used to greater efficiency in the management of the
forests and people. Nevertheless, the implementation of participatory land use planning as
the preferred strategy for biodiversity conservation in the country, did not result in
community empowerment or self-mobilisation in the participatory approach process
Redescriptions of the European Anthrenus Geoffroy, 1762 belonging to the subgenus Helocerus Mulsant & Rey, 1868 (Coleoptera, Dermestidae, Megatominae)
Get PDFSo far three Anthrenus Geoffroy, 1762 species belonging to the subgenus Helocerus Mulsant & Rey, 1868 are
known from Europe: Anthrenus (H.) fuscus Olivier, 1789, Anthrenus (H.) minutus Erichson, 1845, and Anthrenus (H.)
polonicus Mroczkowski, 1951 (Coleoptera, Dermestidae, Megatominae). Only A. (H.) polonicus has been adequately
described in the literature. In the current study, all three species are redescribed with genitalia and external
characters imaged. Differences among the species at the genital level confirm species validity. Among species habitus patterning was described to facilitate field-based identification
Language anxiety in EFL and ESL academic environments
Get PDFAlthough past research has shown significant associations between language anxiety and different linguistic factors (i.e., language proficiency, self-perceived language competence, and frequency of language usage), so far, few studies have directly compared their interaction in foreign language vs second language speaking environments. This comparison is vital to understanding how local language experience, environment and competence shape language anxiety, shedding light on whether language education should be standardized or tailored to local contexts. To examine the relationships between these three linguistic factors and out-of-class language anxiety, a cross-sectional survey was administered to tertiary education students studying at the Malaysia and China campuses of an English as Medium of Instruction (EMI) university. Of the three linguistic factors studied, only self-perceived language competence, but not language proficiency or frequency of language usage significantly predicted language anxiety in both groups. In addition, the Malaysian speakers, despite being more competent English users, reported higher anxiety levels than the Chinese speakers in some of the language use scenarios. These results suggest that identity-based factors play a more significant role than competence in predicting language anxiety in these proficient English users, with these effects influenced by the differing socio-linguistic expectations of English proficiency in the two countries
Recyclable base-triggered “debond-on-demand” aliphatic polyurethane adhesives: engineering adhesion for use in inkjet formulations
Get PDFWhile strong polymeric adhesives are widely valued, their removal can present a significant challenge where substrate recycling is concerned. Recent advancements in “debond-on-demand” adhesives have shown promising enhancements in adhesive strength and debondability. However, they often face a choice between increased adhesive strength or the rate and degree of debonding. Here we report using a rapidly base degradable chain-extender within a series of polyurethanes which possess tailorable adhesive characteristics. These chain-extended polyurethanes (CEPUs) possess high shear strength (8.20 MPa) which upon exposure to base solutions depolymerise (up to 88% loss in Mn) facilitating up to 92% loss in shear strength after only 30 min. Formulation of the CEPUs into inks suitable for continuous inkjet (CIJ) printing produced defined images which upon treatment with base solutions could be removed from the substrate. Having been engineered for circularity, the parent CEPUs can be recycled postdegradation into daughter CEPUs, maintaining their depolymerizable and “debond-on-demand” properties. This work highlights how commercially available starting materials can be utilized to generate highly tailorable polymeric adhesives and inkjet binders capable of rapid depolymerization, ultimately providing an industrially attractive system to increase the recyclability and sustainability of waste materials
Evaluating seasonal forecast improvements over the past two decades
Get PDFSeasonal forecasting systems have been operational for over two decades. Here we present a systematic analysis of the performance of operational seasonal forecasting models since their inception. We analyse seasonal forecasting systems from three major international operational centres that have continuously produced and coordinated on operational seasonal forecasts over the past 20 years. Due to the small sample size of available forecasts it is difficult to draw meaningful conclusions using historical operational forecasts alone, therefore we primarily focus on available model hindcasts. Our analysis, which accounts for differences in ensemble size and period across the forecasting systems, demonstrates that there have been clear improvements in some regions through the different model eras. For both the boreal winter and summer hindcasts, there have been significant improvements in forecasting the tropical regions, which are concurrent with improvements in the skill of tropical sea surface temperature (SST) forecasts. These improvements in the tropics are associated with increased predictability of temperature and precipitation across various continental regions on seasonal timescales. For the extratropics, the picture is more mixed, with strong improvements only evident during the boreal winter season over the North Pacific and North America. The sources of improvement over the winter extratropics are found to be strongly related to improvements in tropical SST skill and related improvements in the strength of the El Nino/Southern Oscillation (ENSO) teleconnection to the Pacific/North America pattern (PNA). Improvements of seasonal forecast skill over the rest of the extratropics, such as over Eurasia, are generally absent or patchy in individual models. The improvements that are found are most pronounced in the newest era models and are broadly associated with improvements in atmospheric model resolution. These improvements in skill are also evident in representative multi-model ensembles that more closely represent how operational forecasts are used in practice