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Ultra-slow self-similar coarsening of physical fibrillar gels formed by semiflexible polymers
Get PDFBiopolymers tend to form fibrils that self-assemble into open network structures. While permanently crosslinked flexible polymers are relatively well understood, structure–property relationships of open networks and pseudo-gels formed by bundles of biopolymers are still controversial. Here we employ a generic coarse-grained bead-spring chain model incorporating semiflexibility and cohesive nonbonded interactions, that forms physical instead of chemical crosslinks. For flexible chains, the cohesive forces lead to the formation of a droplet phase while, at the same concentration, stiffer chains form bundles that self-assemble into percolated networks. From comprehensive molecular dynamics simulations we find that the reversible crosslinks allow for permanent relaxation processes. However, the associated reorganization of the filamentous network is severely hindered, leading to aging of its
topology. Based on morphometric analyses, the ultra-slow coarsening in these systems is proven to be self-similar, which implies a number of scaling relations between structural quantities as the networks age. The percolated structures are characterized by different dynamic regimes of slow, anomalous diffusion with highly non-Gaussian displacements. Relaxation dynamics is found to become extremely slow already on moderate length scales and further slowing down as coarsening proceeds. Using a minimal model supported by observations on filament rupture and rearrangement, our study helps to shed light on various interrelated structural and dynamical aspects of coarsening nonergodic systems relevant for fibrous networks, pseudo-gels, and physical fibrillar gels
Landscape evolution of the Bolivian Amazon controlled by uplift events dated 13,000, 10,000 and 6000 cal yr BP
Get PDFThe Llanos de Moxos in the Bolivian Amazon, the second largest South American wetland, hosts many endemic
species and a rich archaeological record that spans the entire Holocene. Despite its ecological and archaeological
importance, very little is known about its Holocene environmental history. A growing body of evidence suggests
that neotectonics played an important role in shaping its modern landscape and controlling past flooding dynamics,
but the chronology and vertical displacements of past tectonic events are still largely unknown. Here, we
present new data from a core taken at Lake Oceano, a large ria lake in the northern part of the Llanos de Moxos.
To identify changes in the lithology and environment, we performed a battery of analyses, such as XRF scanning,
mineralogy, granulometry, C/N and C and N stable isotopes, and also built an age-depth model using eighteen
radiocarbon dates obtained from accelerator mass spectrometry (AMS) determinations. Based on the sedimentology and chemical analyses, we identified three major disturbances in the lake sedimentation that we interpret as positive tectonic events (i.e., tectonic uplifts). The first identified event occurred at approximately 13,400 cal yr BP and led to the formation of the lake by blocking the river course. A second uplift event took place around 10,000 cal yr BP, accompanied by a significant change in the geochemistry of the lake sediments. Furthermore, we have verified a third event at 6000 cal yr BP, previously recognized as responsible for the onset of Lake Rogaguado (aprox. 100 km NE of Lake Oceano), one of the largest lakes in South America. Overall, we show that ria lakes can provide key sedimentary archives to reconstruct the past timing and intensity of tectonic events. We discuss the interplay between tectonics and climate, highlighting the connection between tectonics and the region’s flood history, with crucial implications for the interpretation of both archaeological and palaeoecological records throughout the Holocene
Semaglutide aggregates into oligomeric micelles and short fibrils in aqueous solution
Get PDFSemaglutide is a lipopeptide with important applications in the treatment of diabetes, obesity, and other conditions. This class of drug (glucagon-like peptide-1 agonists and other lipidated peptides) may be susceptible to aggregation due to the tendency of lipopeptides to self-assemble into various nanostructures. Here, we show using cryogenic-TEM, small-angle X-ray scattering, and molecular dynamics simulations that semaglutide in aqueous solution undergoes slow aggregation into spherical micelles in water at sufficiently high concentration. A small population of needle-shaped fibril aggregates is also observed. At a lower concentration, dimer and trimer structures are formed. The micelles, once formed, are stable toward further aging. The aggregation influences the effect of semaglutide on the permeability of an epithelial gut model membrane of Caco-2 cells. These findings are expected to be important in understanding the long-term stability of semaglutide solutions and the potential effects of aggregation on therapeutic efficacy
Analyzing state support to non-state actors – part I: primary obligations and attribution
No full textTechno-legal geographies: consumer drone misuse and harms
Get PDFDrones increasingly feature beyond battlefields, deployed across civil, commercial and hobbyist applications and contexts. So too are off-the-shelf consumer drones increasingly being misused. From their outfitting with improvised weapons to the deployment of drones to harass individuals, both incidents involving consumer drones and the (potential) harms accompanying them, have diversified. Interested in emerging techno-legal geographies of consumer drone misuse, this paper deploys a feminist analytic to interrogate drone-enabled harms. It brings drone geographies into dialogue with feminist legal and digital geographies, to interrogate the drone as a technology encountered and interpreted in legal terms and accompanied by gendered impacts. Responding to calls for the expansion of the methodological toolkit underpinning the drone’s study while also affording geolegal attention to the drone, the paper draws upon focus groups designed in collaboration by a geographer and barrister and bringing together lawyers across diverse specialisms in an exploration of drone misuse and harm. Through analysis of examples of drone misuse and the legal process accompanying its investigation, we underscore both that drones can introduce novel as well as extend existing technology-enabled harms, and that such harms exceed the confines of aviation law, cutting across multiple areas of law. Collectively, we argue that employing a feminist approach in the drone’s critical analysis acts to foreground diversified drone harms and their uneven impacts
Evaluating firearm examiner testimony using large language models: a comparison of standard and knowledge-enhanced AI systems
Get PDFObjective: This study evaluated the decision-making of Large Language Models (LLMs) in interpreting firearm examiner testimony by comparing a standard LLM to one enhanced with forensic science knowledge. Method: Following the experimental paradigm of Garrett et al. (2020), we assessed whether LLMs mirrored human decision patterns and if specialized knowledge led to more critical evaluations of forensic claims. We employed a 2 × 2 × 7 between-subjects design with three independent variables: LLM configuration (standard vs. knowledge-enhanced), cross-examination presence (yes vs. no), and conclusion language (seven variations). Each model condition performed 200 repetitions per scenario. This yielded a total of 5,600 measures of binary verdicts, guilt probability ratings, and credibility assessments. Results: LLMs showed low conviction rates (9.4%) across conditions, with logical variations as a function of the way in which the firearm expert’s conclusion was formulated. Cross-examination produced lower guilt assessments and scientific credibility ratings. Importantly, knowledge-enhanced LLMs demonstrated significantly more conservative evaluations of firearm evidence across all match conditions compared to standard LLMs. Conclusions: LLMs, particularly when enhanced with domain-specific knowledge, showed advantages in evaluating complex scientific evidence compared to human jurors in Garrett et al. (2020), suggesting potential applications for AI systems in supporting legal decision-making
Reconciling Britain’s agricultural trade policy initiatives with world trade rules: 1960–1975
Get PDFBetween 1960 and 1972 successive British governments explored, and sometimes pursued, a series of agricultural trade policy initiatives designed to shift the burden of supporting UK farmers from taxpayers to consumers, and to reduce the UK’s agri-food imports by expanding home production. These included a minimum import price scheme for cereals; a Selective Expansion Programme; debate about Agriculture’s Import Saving Role; and 1970 proposals for a fundamental change to farm policy that would apply whether or not the UK joined the European Communities (EC). Prior to EC membership the rules of the General Agreement on Tariffs and Trade (GATT), bilateral agreements with a number of countries, and pressure from the UK’s trading partners (particularly the United States) constrained its room for manoeuvre. Consequently, this dimension of farm policy could not safely be left to agriculture ministers and the Treasury, but was one that involved other departments, and prime ministers, as it necessitated detailed international negotiations. Following EC entry, GATT Article XXIV deliberations and the UK’s renegotiation of its terms of entry failed to secure meaningful reform of the common agricultural policy (CAP). The 1975 referendum confirming EC membership meant the UK no longer had an independent agri-food trade policy
Disasters and technological upgrading measured by changes in demand for ICT labour: estimating the impacts with text
Get PDFExtensive literature has studied the economic impact of disasters. However, specific impacts on labour markets have received less attention. Using a massive earthquake (> 8.0 Mw) that struck Chile in 2010 and proprietary data from a Chilean online job board (4136 job postings published between 2008 and 2012), we examine changes in demand for Information and Communications Technologies, ICT, related labour as a proxy for technological upgrading, by assuming that ICT and related technologies drive much of the technical change in production. We implement a structural topic model to discover and estimate the difference in the prevalence of ICT and Construction labour, among others. Our results show that ICT labour does not change. In contrast, Construction labour significantly differed after the disaster, suggesting that reconstruction activities led to employment differences. Our results suggest that there was no substantive technological replacement following the earthquake
Esports: transforming education
Get PDFIn 2025 Digital Schoolhouse collaborated with the Institute of Education,University of Reading to evaluate perceptions of the development of esports initiatives in participating educational settings over time and its potential impact on these communities and their students.
The study focused on three research questions:
A. How was the DSH esports initiative introduced and
implemented within participating schools, and what factors
shaped its development?
B. What impact did the initiative have on student engagement,
inclusion, wellbeing, and educational or career aspirations?
C. What challenges and barriers emerged during the initiative,
and how might they be addressed to ensure equitable and
sustainable delivery in the future?
The data demonstrated that the
structured, well-supported DSH esports
programme had a clear and positive impact
on student engagement, career awareness,
school participation, and confidence of
both students and staff.
It also demonstrated that esports
as a tool for social inclusion can be
particularly impactful for marginalised
as well as neurodivergent students,
creating opportunities for social bonding,
communication, and confidence-building.
The DSH framework enabled teachers,
even those with minimal experience
in playing video games, to confidently
run esports activities. For many, initial
participation was seen as an exciting
and supported experiment.
After witnessing positive outcomes in the
first year, schools and colleges chose to
continue, with growing student demand
often supporting schools to recognise
and integrate esports in wider school
practices. In some cases, teachers went
on to organise their own in-house or
trust-wide tournaments as well as
enter external competitions.
While the findings come from schools
and colleges already within the DSH
programme, and therefore benefitting
from its low-barrier, high-support model,
the results suggest that structured,
well-resourced esports initiatives
have strong potential to create lasting
educational and social benefits.
Future research could explore how
these outcomes compare with esports
programmes run without DSH’s
extensive support
The impact of uncertainty on fan interest surrounding multiple outcomes in open European football leagues
Get PDFThis paper uses searches via Google to evaluate the importance of uncertainty in driving demand for entertainment events. We consider various dimensions of uncertainty of outcome in European football to examine whether the removal of uncertainty surrounding the winner of a competition before its conclusion reduces interest. We find a significant decrease in interest, although this appears mitigated by the existence of multiple objectives, such as qualifying for European competitions and avoiding relegation. We conclude that such a diversified and open structure (including promotion and relegation) is desirable in leagues that do not have a final play-off system