Evaluation of the nonlinear surface resistance of REBCO coated conductors for their use in the FCC-hh beam screen

To assess the feasibility of using high-temperature superconductors for the beam screens of future circular colliders, we have undertaken a study of the power dependence of the microwave surface resistance in state-of-the-art REBCO coated conductors at about 8GHz and 50K. We have employed a dielectric resonator to produce radio-frequency electromagnetic fields on the surface of the coated conductors having amplitudes similar to those generated by proton bunches circulating in the vacuum chamber of the proposed hadron-hadron Future Circular Collider at CERN. We show that surface resistances in REBCO coated conductors without artificial pinning centers are more affected by a radio-frequency magnetic field than those containing nano-inclusions. Despite that, at 8GHz, 50K, and 9T, most REBCO coated conductors studied outperform copper in terms of surface resistance, with the best sample having a 2.3mΩ surface resistance while being subject to an RF field 2.5 times stronger than that in the FCC-hh. We also extrapolate the measured data to 16T and 1GHz, the actual FCC-hh dipole magnetic field, and mid beam frequency spectrum, demonstrating the possibility of lowering the surface resistance of the vacuum chamber by up to two orders of magnitude compared to copper. Further, we discuss the correlation between the time structure of the electromagnetic fields provided by vector network analyzers compared to the proton bunches' time structure in the collider and present the effect of low alternating magnetic fields on vortex displacement and the possibility of demagnetization of superconducting samples.

Re-examination of the Time Structure of the SN1987A Neutrino Burst Data in Kamiokande-II

The seven seconds’ gap in the Kamiokande-II SN1987A neutrino data is reexamined.

Structural Humility

In this article I discuss various humility theses about individuals and intrinsic properties as discussed by authors such as David Lewis. I argue that we should accept a similar humility thesis about the world’s space-time structure regardless of which metaphysics of space-time we accept. I argue this undercuts some important motivations opting in for an ontic structural realist metaphysic.

Effectiveness and Injury Risk during Timber Forwarding with a Quad Bike in Early Thinning

Within the majority of forest areas where timber is harvested for industrial and energy purposes, working technologies using highly efficient multi-operational machinery and equipment are employed. The situation is different in fragmented, privately owned forests. In such forests, timber harvesting is mainly based on motor-manual technologies with a high proportion of manual labor, both at the stage of felling and timber processing and at the stage of its transport. The study aimed to characterize the work time structure of the ATV unit driver and his helper, to determine the productivity of this team, and to estimate the risk of injury during manual loading and unloading. Based on the data collected during the field research, the theoretical work time structure, work productivity and costs, and injury risk were estimated as a result of using a professional small trailer equipped with a hydraulic crane for timber forwarding, designed for aggregation with the ATV. The average, calculated productivity of timber forwarding (over an average distance of about 500 m) with manual loading and unloading was almost twice as low as the estimated average productivity of forwarding with mechanical loading and unloading using a hydraulic crane. The total unit costs (including labor costs) of forwarding with manual loading and unloading were almost threefold higher than those of forwarding using a trailer with a hydraulic crane. The use of small forest trailers equipped with a hydraulic crane not only ensures higher productivity and cost effectiveness but also allows reducing (even by several percent) the inconvenience of manual timber handling and the risk of strain of the musculoskeletal system.

Real-Time Structure Search and Structure Classification for AlphaFold Protein Models

AlphaFold2 showed a substantial improvement in the accuracy of protein structure prediction. Following the release of the software, whole-proteome protein structure predictions by AlphaFold2 for 21 organisms were made publicly available. Here, we developed the infrastructure, 3D-AF-Surfer, to enable real-time structure-based search for the AlphaFold2 models by combining molecular surface representation with 3D Zernike descriptors and deep neural networks.

Comparison of Japanese and Scottish Mother–Infant Intersubjectivity: Resonance of Timing, Anticipation, and Empathy During Feeding

Feeding involves communication between mothers and infants and requires precise synchrony in a special triadic relationship with the food. It is deeply related to their intersubjectivity. This study compared the development of mother–infant intersubjectivity through interactional synchrony in feeding between 11 Japanese and 10 Scottish mother–infant dyads, observed at 6 and 9 months by video. Japanese mothers were more deliberate in feeding at an earlier age, whereas Scottish mothers were significantly more coercive than Japanese mothers at an earlier age. Japanese mothers brought the spoon to infants with a pause to adjust the timing of insertion to match their infants’ readiness, whereas this pause was not observed in Scottish mothers. Isomorphic mouth opening between mothers and infants was observed. This empathic maternal display is an important element of intersubjectivity in infant feeding that differed between Scottish and Japanese mothers. Scottish mothers’ mouth opening always followed their infants’ mouth opening, but about half of Japanese mothers preceded their infants. Further, the mouths of Scottish infants and mothers opened almost at the same time as spoon insertion. In contrast, Japanese mothers’ mouth opening did not co-occur with the insertion but was close to spoon arrival, a subtle but important difference that allows for greater infant autonomy. The time structure of Scottish mother-infant interactions was simpler and more predictable at 9 months than in Japan, where the structure was more variable, likely due to a stronger regulation by Scottish mothers. In conclusion, Scottish mother-infant intersubjectivity is characterized as more maternally reactive and mother-centered, whereas Japanese mother-infant intersubjectivity is characterized as more maternally empathetic and infant-centered. Cultural differences in intersubjectivity during feeding between Japan and Scotland are further discussed in relation to triadic relationships and parenting styles.

Smoothing age/time structure of HIV prevalence, for optimal use in synthetic cohort based incidence estimation

Population-based surveys which ascertain HIV status are conducted in heavily affected countries, with the estimation of incidence being a primary goal. Numerous methods exist under the umbrella of ‘synthetic cohort analysis’, by which we mean estimating incidence from the age/time structure of prevalence (given knowledge on mortality). However, not enough attention has been given to how serostatus data is ‘smoothed’ into a time/age-dependent prevalence, so as to optimise the estimation of incidence.To support this and other related investigations, we developed a comprehensive simulation environment in which we simulate age/time structured SI type epidemics and surveys. Scenarios are flexibly defined by demographic rates (fertility, incidence and mortality – dependent, as appropriate, on age, time, and time-since-infection) without any reference to underlying causative processes/parameters. Primarily using 1) a simulated epidemiological scenario inspired by what is seen in the hyper-endemic HIV affected regions, and 2) pairs of cross-sectional surveys, we explored A) options for extracting the age/time structure of prevalence so as to optimise the use of the formal incidence estimation framework of Mahiane et al, and B) aspects of survey design such as the interaction of epidemic details, sample-size/sampling-density and inter-survey interval.Much as in our companion piece which crucially investigated the use of ‘recent infection’ (whereas the present analysis hinges fundamentally on the estimation of the prevalence gradient) we propose a ‘one size fits most’ process for conducting ‘synthetic cohort’ analyses of large population survey data sets, for HIV incidence estimation: fitting a generalised linear model for prevalence, separately for each age/time point where an incidence estimate is desired, using a ‘moving window’ data inclusion rule. Overall, even in very high incidence settings, sampling density requirements are onerous.The general default approach we propose for fitting HIV prevalence to data as a function of age and time appears to be broadly stable over various epidemiological stages. Particular scenarios of interest, and the applicable options for survey design and analysis, can readily be more closely investigated using our approach. We note that it is often unrealistic to expect even large household based surveys to provide meaningful incidence estimates outside of priority groups like young women, where incidence is often particularly high.