Some observers of the data economy have proposed that we treat data as labor. But are data contributions labor? Our folk conception of work emphasizes its importance and effort, such that work has a special interpersonal priority and deserves appreciation and compensation. The folk conception does not generally favor counting data as work, and so it serves as an error theory for reluctance to regulate data as labor. In contrast, labor regulation and policy focus on the political economy of labor, and in particular the bargaining dynamics that participants in a labor market face. Labor regulation aims to protect workers against the threats characteristically posed by such bargaining dynamics. Data-transferring interactions between internet platforms and users share similar bargaining dynamics, and so there is a promising functional similarity between labor regulation and proposals for data regulation that would facilitate data strikes and data unions.

This study aimed to determine the prevalence of gastrointestinal parasites in alpacas on selected farms in Poland. In July and August 2019 and August 2021, 223 samples from six commercial farms were examined using coproscopic techniques. The total percentage of alpacas infected with intestinal parasites was 57.7%. Eggs of Nematodirus sp. were found in 28.9%, Trichostrongylus sp. in 15.5%, Strongyloides sp. in 13.4%, Camelostrongylus sp. in 11.3%, other strongyle-type in 12.4%, Trichuris sp. in 3.1%, Capillaria spp. in 2.1%, Oesophagostomum sp. in 1.0% and eggs of Moniezia sp. in 1.0% of individuals. Oocysts of Eimeria macusaniensis were found in 8.2%, Eimeria sp. in 4.1%, and Cryptosporidium sp. in 3.1% of animals. Redundancy analysis showed that parasites and their number in faeces were related to the individual’s country of origin, sex and age. Females had significantly more eggs of parasites than males. More significant parasite infection was recorded in younger individuals. Moreover, the most infected were individuals from Germany. Some of the described parasites in tested alpacas have zoonotic potential. Due to the possibility of introducing parasites native to alpacas and acquiring species parasitising wild and farmed animals in Europe, permanent veterinary monitoring of animals imported from other regions is necessary.

Recent research has explored gender ratios in orchestras but not specifically in brass playing, a historically masculine field. Three studies investigated gender ratios in a variety of brass-playing situations. Public domain and questionnaire data were analysed using descriptive statistics, and a chi-square test found a significant effect of instrument size on gender ratios. The highest percentage of female brass players was found in youth ensembles, followed by the freelance workforce, semi-professional brass bands and then professional orchestras, indicating a leaky pipeline effect. These results show that women are still under-represented in most brass-playing contexts, particularly the most prestigious positions, and that more can be done in music education to change this.

Neglect remains understudied compared to other forms of maltreatment. While studies have shown that neglect has negative effects on mental health in adolescence, yet unresolved is whether these impacts result from critical period or cumulative effects. In the present article, we use a novel approach to compare these two hypotheses from the impact of two types of neglect, failure to provide (FTP) and lack of supervision (LOS), on adolescent depression and internalizing symptoms. Data derive from the LONGSCAN consortium, a diverse, multi-site, prospective study of children from approximately age 2–16. Despite our hypothesis that the critical period of early childhood would have the greatest impact on adolescent internalizing mental health, exposure to neglect during the critical period of adolescence (ages 12–16) was the best-fitting model for the effects of FTP neglect on depression, and the effects of LOS neglect on both depression and internalizing symptoms. The cumulative model (exposure across all time periods) best explained the effects of FTP neglect on internalizing symptoms. Results were robust to the addition of control variables, including other forms of maltreatment. These findings demonstrate that responding to neglect into adolescence must be considered as urgent for child welfare systems.

In this paper, we prove an optimal isoperimetric inequality for spacelike, compact, star-shaped, and $2$-convex hypersurfaces in de Sitter space.

A distributed cooperative guidance law without numerical singularities is proposed for the simultaneous attack a stationary target by multiple vehicles with field-of-view constraints. Firstly, the vehicle engagement motion model is transformed into a multi-agent model. Then, based on the state-constrained consensus protocol, a coordination control law with field-of-view (FOV) constraints is proposed. Finally, the cooperative guidance law has been improved to make it more suitable for practical application. Numerical simulations verified the effectiveness and robustness of the proposed guidance law in the presence of acceleration saturation, communication delays and measurement noise.

Helices are one of the most frequently encountered symmetries in biological assemblies. Helical symmetry has been exploited in electron microscopic studies as a limited number of filament images, in principle, can provide all the information needed to do a three-dimensional reconstruction of a polymer. Over the past 25 years, three-dimensional reconstructions of helical polymers from cryo-EM images have shifted completely from Fourier–Bessel methods to single-particle approaches. The single-particle approaches have allowed people to surmount the problem that very few biological polymers are crystalline in order, and despite the flexibility and heterogeneity present in most of these polymers, reaching a resolution where accurate atomic models can be built has now become the standard. While determining the correct helical symmetry may be very simple for something like F-actin, for many other polymers, particularly those formed from small peptides, it can be much more challenging. This review discusses why symmetry determination can be problematic, and why trial-and-error methods are still the best approach. Studies of many macromolecular assemblies, such as icosahedral capsids, have usually found that not imposing symmetry leads to a great reduction in resolution while at the same time revealing possibly interesting asymmetric features. We show that for certain helical assemblies asymmetric reconstructions can sometimes lead to greatly improved resolution. Further, in the case of supercoiled flagellar filaments from bacteria and archaea, we show that the imposition of helical symmetry can not only be wrong, but is not necessary, and obscures the mechanisms whereby these filaments supercoil.

Contrails are a major contributor to the climate effect of aviation. Mitigation efforts and technological improvements aim to reduce the contrail climate effect. Many currently discussed innovations (like using sustainable aviation fuels (SAFs) or hydrogen) affect the physical processes and phenomena during contrail formation. Hence, understanding and analysing contrail formation is of great importance in the context of climate research. Ice crystal formation in a nascent contrail is completed within the first seconds after the engine exhaust is emitted. In the past, numerical models treating this early stage typically involved either a 3D or 0D approach. Whereas 3D models are computationally expensive, restricting the number of simulations that could be performed, less expensive 0D models allow to explore a larger parameter space but neglect plume heterogeneity and use a prescribed plume dilution. We present the new dynamical framework RadMod for contrail formation simulations that describes the evolution of a turbulent round jet emitted from an aircraft engine. Relative to large-eddy simulation (LES) or Reynolds-averaged Navier-Stokes (RANS) 3D models of contrail formation, our model is computationally less expensive, enabling extensive parameter studies. The model accounts for the mixing of the hot and moist exhaust air with the cold ambient air through the solution of the two-dimensional advection-diffusion equation of momentum, temperature, and water vapour. The validation of our model is conducted through comparisons with empirical relationships and CFD results. In the near future, this model will be combined with an existing microphysical model, resulting in a contrail formation model of intermediate complexity.

This paper is concerned with a singular limit of the Kobayashi–Warren–Carter system, a phase field system modelling the evolutions of structures of grains. Under a suitable scaling, the limit system is formally derived when the interface thickness parameter tends to zero. Different from many other problems, it turns out that the limit system is a system involving fractional time derivatives, although the original system is a simple gradient flow. A rigorous derivation is given when the problem is reduced to a gradient flow of a single-well Modica–Mortola functional in a one-dimensional setting.

What benefits do inclusive institutions offer authoritarian rulers? Previous research has studied delegate behaviour in authoritarian institutions but has been less well-equipped to assess government reactions to it. Analysing the case of one People's Political Consultative Conference in China, I argue that an overlooked key benefit of inclusive institutions is their provision of expertise. Drawing on novel data comprising more than 9,000 policy suggestions submitted by delegates, delegates' biographies and the corresponding government responses, I illustrate that the government generally values suggestions that signal expertise. While this is especially true for departments of a more technocratic nature, I also find that members of the institutional leadership are systematically favoured. These findings provide an important addition to our understanding of the role of authoritarian institutions in policymaking processes.

Recent scholarship finds that exposure to mass shootings has no effect on Democratic vote shares. While arguably a reasonable proxy for public demand for heightened gun control, this outcome nonetheless reflects myriad issue concerns, with guns being just one issue typically dwarfed in importance by the attention given in electoral campaigns to jobs, the economy, and other social issues. Our research improves the issue-domain correspondence between treatment and outcome by analyzing voting directly on gun policy. We leverage a mass shooting that occurred in Washington state shortly before residents voted on a ballot measure to regulate firearms. Critically, a previous measure on firearms appeared on the ballot in Washington 2 years prior, enabling our analysis to control for pretreatment support for gun control. Across various model specifications, we find that proximity to the shooting was associated with increased support for gun control. We replicate this finding with three additional shootings.

This paper presents the results of reverse-engineering (RE) strategies, surface roughness and computational fluid dynamics (CFD) modelling for a Wren100 micro gas turbine (MGT). Utilising silicone moulds and resin tooling, precise blade geometry capture was achieved for 3D reconstruction allowing for discrete and parametric geometric models to be created. Using these geometries, CFD simulations employing both Reynolds-averaged Navier–Stokes (RANS) and large eddy simulation (LES) models, alongside experimental wind tunnel cascade tests, were used to evaluate these reverse engineering strategies. The results show that while the parametric model captures overall MGT performance with fewer parameters, the discrete model provides enhanced accuracy, highlighting its suitability for detailed aerodynamic analyses. Contrary to initial expectations, surface roughness exhibited a noticeable impact on performance despite the lower Reynolds numbers (40,000), as demonstrated by the CFD model and wind tunnel experiments. The results indicate that surface roughness can reduce laminar separation bubbles on the blade leading edge, delay the onset of transition, and mitigate secondary flow losses. Overall, this study contributes to knowledge advancement in turbine blade reverse engineering and aerodynamics by detailing the impact of surface roughness on performance.

In the 21st century, we are increasingly exposed to music created entirely on computers. This article shows how pioneering music teachers approach the challenge of teaching music on the laptop computer in the context of one-to-one musical instrument lessons. Interviews and observations with five laptop teachers in Norwegian secondary schools enabled the authors to explore characteristic challenges in this field. This study explored two research questions: What are the instructional strategies, content and ‘repertoire’ in music lessons on laptop computer? How have teachers experienced the laptop’s evolutionary process towards legitimation?