Methacrylate-based copolymers as tunable hosts for triplet–triplet annihilation upconversion

The ability to convert light to higher energies through triplet–triplet annihilation upconversion (TTA-UC) is attractive for a range of applications including solar energy harvesting, bioimaging and anti-counterfeiting. Practical applications require integration of the TTA-UC chromophores within a suitable host, which leads to a compromise between the high upconversion efficiencies achievable in liquids and the durability of solids. Herein, we present a series of methacrylate copolymers as TTA-UC hosts, in which the glass transition temperature (Tg), and hence upconversion efficiency can be tuned by varying the co-monomer ratios (n-hexyl methacrylate (HMA) and 2,2,2-trifluoroethyl methacrylate (TFEMA)). Using the model sensitiser/emitter pair of palladium(II) octaethylporphyrin (PdOEP) and diphenylanthracene (DPA), the upconversion quantum yield was found to increase with decreasing glass transition temperature, reaching a maximum of 1.6 ± 0.2% in air at room temperature. Kinetic analysis of the upconversion and phosphorescence decays reveal that increased PdOEP aggregation in the glassy polymers leads to a competitive non-radiative relaxation pathway that quenches the triplet state. Notably, the threshold intensity is highly sensitive to the glass transition temperature, ranging from 1250 mW cm−2 for PHMA90TFEMA10 (Tg = −9.4 °C) to ∼200 mW cm−2 for more ‘glassy’ hosts, e.g. PHMA33TFEMA67 (Tg = 20.1 °C), suggesting the TTA-UC mechanism switches from diffusion-based collisions to triplet exciton migration at localised sensitiser–emitter pairs

Galaxy properties from the outskirts to the core of a protocluster at z = 3.70

We study the dependence of galaxy properties on their spatial position within a protocluster by carrying out follow-up spectroscopy on a protocluster candidate selected from the wide-field imaging of the Hyper Suprime Cam Subaru Strategic Programme. In the 4.5 surface-overdense region of -dropout galaxies, we now spectroscopically confirm that thirteen galaxies, at least, are clustering in a narrow redshift range of Δ < 0.05 around = 3.70. Next, we investigate the physical properties and three-dimensional (3D) distribution of the protocluster’s member galaxies. Based on spectroscopically-confirmed-dropout galaxies, we find an overabundance of rest-frame ultraviolet (UV) bright galaxies in the protocluster. The UV brightest protocluster member turns out to be an active galactic nucleus, and the other UV brighter members tend to show smaller Ly equivalent widths than field counterparts. The member galaxies tend to densely populate near the 3D centre of the protocluster,but the separation from the nearest neighbour rather than the distance from the centre of the protocluster is more tightly correlated to galaxy properties, implying that the protocluster is still in an early phase of cluster formation and only close neighbours have a significant impact on the physical properties of protocluster members. The number density of massive galaxies, selected from an archival photometric-redshift catalogue, is higher near the centre of the protocluster, while dusty starburst galaxies are distributed on the outskirts. The protocluster thus appears to consist of multiple galaxy populations, whose spatial distributions reveal the developmental stage of the galaxy cluster

Quantifying animal social behaviour with ecological field methods

Field studies of social behaviour are challenging due to the need to record or infer interactions between multiple individuals, often under suboptimal environmental conditions or with potential disturbance by observers. Due to the limited field techniques available, we present a novel method to quantify social behaviours in the field by comparing the counts of individuals caught in traps across multiple locations sampled simultaneously. The distribution of individuals between traps gives the extent of aggregation, and phenotypic data allow for inference of non-random assortment. As a case study, we applied this method to populations of three-spined sticklebacks (Gasterosteus aculeatus) in freshwater ponds, using minnow traps. As expected, we observed a strong trend for aggregation. We were able to describe the ecological drivers of aggregation, comparing environmental and phenotypic conditions across sites. Aggregation was not related to environmental parameters, but was negatively associated with the proportion of breeding males caught during the breeding season. No evidence for phenotypic assortment based on body size was found. These results demonstrate that widely available ecological equipment can address questions related to social behaviour. This cost-effective approach, avoiding the tagging of individuals and minimizing extended observer disturbance, can be applied across various habitats and species

The promise of teacher-led physical activity strategies informed by pupil data

Background:Physical activity is important for children’s physical, mental and cognitive wellbeing, but many children are insufficiently active. Schools offer a promising setting in which to enable positive health behaviours and teachers can play an influential role in facilitating pupils’ physical activity. The aim of this study was to use pupils’ physical activity data from wearables to inform teacher-led strategies to improve pupils’ physical activity outcomes.Methods:Participants included 11 teachers/classes, and 228 pupils aged 8–11 years from eight primary-schools in England. Baseline pupil physical activity was measured for 2 weeks using a commercially available accelerometer, before data visualisations were used to inform teacher-led strategies with the aim of improving pupils’ physical activity. These strategies were then implemented, with physical activity being measured post-data-sharing discussions. Mixed-methods analysis explored the feasibility of using data visualisations to inform teachers’ understanding of their pupils’ physical activity and the development and implementation of teacher-led, school-specific strategies to increase pupils’ physical activity.Results:Teachers understood and reflected on the data visualisations and used their knowledge of the school context to develop and implement bespoke school-specific strategies across the school day which successfully increased physical activity. Strategies included altering the physical or social environment, providing more opportunities and addressing physical activity inequalities. Teachers were encouraged when data showed increases in pupils’ physical activity and many expressed the desire to continue addressing physical activity, with a particular focus on the least active pupils.Conclusion:These findings suggest that data-driven insights could be used effectively to inform school-based, teacher-led strategies to increase physical activity

An Energy-Aware RIoT System:Analysis, Modeling and Prediction in the SUPERIOT Framework

This paper presents a comprehensive analysis of the energy consumption characteristics of a Silicon (Si)-based Reconfigurable IoT (RIoT) node developed in the initial phase of the SUPERIOT project, focusing on key operating states, including Bluetooth Low Energy (BLE) communication, Narrow-Band Visible Light Communication (NBVLC), sensing, and E-ink display. Extensive measurements were conducted to establish a detailed energy profile, which serves as a benchmark for evaluating the effectiveness of subsequent optimizations and future node iterations. To minimize the energy consumption, multiple optimizations were implemented at both the software and hardware levels, achieving a reduction of over 60% in total energy usage through software modifications alone. Further improvements were realized by optimizing the E-ink display driving waveform and implementing a very low-power mode for non-communication activities. Based on the measured data, three measurement-based energy consumption models were developed to characterize the energy behavior of the node under: (i) normal, unoptimized operation, (ii) low-power, software-optimized operation, and (iii) very low-power, hardware-optimized operation. These models, validated with new measurement data, achieved an accuracy exceeding 97%, confirming their reliability for predicting energy consumption in diverse configurations

Measuring serious violence perpetration:comparison of police-recorded and self-reported data in a UK cohort

IntroductionDetermining risk factors and consequences of serious violence requires accurate measures of violence. Self-reported and police-recorded offending are subject to different sources of bias.ObjectivesTo compare risk of self-reported and police-recorded serious violence perpetration in late adolescence and early adulthood using linked UK birth cohort and police data, to examine the association between cohort participation and police-recorded violence, and to use police-records to impute missing self-reported data on violenceMethodsWe included individuals in the Avon Longitudinal Study of Parents and Children (ALSPAC) who had been informed about the study's use of their linked data and had not opted out of linkage to police records (n = 12,662). We used descriptive statistics and logistic regression to address our objectives. Multiple imputation using chained equations was used to impute self-reported violence data to examine the likely impact of missing data on estimates of prevalence.ResultsSelf-reported violence perpetration in the past year ranged from 5.3% (at 25 years) to 12.9% (at 20 years) among males and 3.2% (at 17, 22, 24 and 25 years) to 6.4% (at 18 years) among females. Police-recorded serious violence was lower at all ages, peaking at 17-18 years (1.7% among males, 0.5% among females). Study participation was lower among people who had or went on to have a police record for serious violence; as a result, the prevalence of self-reported violence in the imputed data was higher (compared to observed data) at all ages.ConclusionsOverall, our study demonstrates the difficulties in measuring violence. While we have shown that a key advantage of linkage to police records is it enables outcomes to be measured irrespective of study participation, police data undercounts serious violence. Further, observational studies may also underestimate violence perpetration as individuals with police-recorded serious violence are less likely to participate in research. Therefore, while record linkage allows the advantages of both official police records and self-reported measures to be exploited, it does not negate their limitations

Engineering the acoustic field with a Mie scatterer for microparticle patterning

The utilization of acoustic fields offers a contactless approach for microparticle manipulation in a miniaturized system, and plays a significant role in medicine, biology, chemistry, and engineering. Due to the acoustic radiation force arising from the scattering of the acoustic waves, small particles in the Rayleigh scattering range can be trapped, whilst their impact on the acoustic field is negligible. Manipulating larger particles in the Mie scattering regime is challenging due to the diverse scattering modes, which impacts the local acoustic field. The rapid movement of free-moving Mie scatterers in an acoustic standing wave field makes it difficult to study the interaction between a sound field and a Mie scatterer in an engineering context. Here, a combined approach that integrates theoretical analysis and experimental investigation was developed to explore the influence of a Mie scatterer on the acoustic field by fabricating an acoustic trapping device featuring a fixed Mie scatterer at its center. We demonstrate that an insonified Mie scatterer can operate as an acoustic emitter in water, enabling dynamic and versatile modulation of the total acoustic field. Such a scatterer can interact with one or multiple incident propagating acoustic waves, leading to the generation of a localized standing wave field in the vicinity of the scatterer. This local field can be controlled by the relative location of the scatterer with respect to the incident field leading to control over the transformation from an incident 1D acoustic field into a 2D acoustic field. This control paves the way for localized and multi-scale micro-object manipulation

Individual behavior and housing setup interact to influence markers of welfare in the critically endangered Hawaiian crow

While some stress can be beneficial for survival, identifying drivers of detrimental stress is essential for improving animal welfare and reproductive outcomes in conservation breeding programs. We examined the interaction between housing and behavioral indicators of temperament, both of which may explain variability in markers of positive and negative (stress) welfare in a critically endangered bird, the ‘alalā (Hawaiian crow; Corvus hawaiiensis). During the 2019 breeding season, we collected behavioral data, including markers of negative welfare (e.g. alarm calling and pace flying), positive welfare (e.g. foraging and preening), and four temperament-like traits (aggression, social connectedness, restfulness, and shy/boldness), on 26 mated pairs engaged in varying breeding stages at a conservation breeding center in Hawaiʻi. All pairs were housed in one of two housing setups: 1) a two-compartment, "breeding" aviary (predicted to be less stressful due to relative seclusion and single-pair occupancy) or, 2) a > 2 compartment “holding” aviary, used to house pairs immediately adjacent to other 'alalā (predicted to be more stressful for 'alalā due to the close proximity of others and the territorial nature of the species). Regardless of housing, we observed lower rates (per min) of positive welfare behaviors in incubating and parent-rearing than non-breeding individuals. However, when we examined the interaction of housing and temperament-like traits, the welfare outcomes were more nuanced. Birds in highly compatible pairs (regardless of enclosure) and, surprisingly, birds in more crowded aviaries (regardless of temperament) exhibited higher rates of positive welfare behaviors. Moreover, non-restful birds had higher mean positive welfare rates when housed in holding aviaries. Although not of primary interest in our study, we also found that average positive welfare behaviors increased over time (across repeated observations on each pair), which were largely associated with the presence or absence of rainfall. Following these results, we recommend future studies in which non-restful and highly compatible ‘alalā pairs are relocated to holding aviaries, as this may increase overall welfare of the breeding population. Additionally, where possible, we recommend future studies control for weather when conducting behavioral observations. Overall, our findings underscore the importance of accounting for differences in behavior among individuals when examining the impact of housing on animal welfare in conservation breeding facilities

The Fosen-Linjen Saga

The 2017-2019 Fosen-Linjen Saga saw the EFTA Court issue diametrically opposed views on the threshold for damages liability arising from breaches of EEA/EU public procurement law. Despite the arguably clear position under EU law following the European Court of Justice’s 2010 Judgment in Spijker—ie that liability in damages under the Remedies Directive only arises when the breach is ‘sufficiently serious’—Fosen-Linjen I stated that a ‘simple breach of public procurement law is in itself sufficient to trigger the liability of the contracting authority’. Such an approach would have created divergence between EEA and EU procurement law and generated undesired effects on the administration of procurement procedures and excessive litigation. Moreover, Fosen-Linjen I showed significant internal and external inconsistencies, which rendered it an unsafe interpretation of the existing rules, tainted by judicial activism on the part of the EFTA Court under its then current composition. Taking the opportunity of a rare second referral, and under a different Court composition, Fosen-Linjen II U-turned and stated that the Remedies Directive ‘does not require that any breach of the rules governing public procurement in itself is sufficient to award damages’. This realigned EEA law with EU law in compliance with the uniform interpretation goal to foster legal homogeneity. This chapter revisits the Fosen-Linjen Saga and offers additional reflections on its implications, especially for a long-overdue review of the Remedies Directive