bluuebunny/crossref_metadata_2025 huggingface dataset:
Design of a flow modulation device to facilitate individualized ventilation in a shared ventilator setup
Authors: Stiers Michiel , Vercauteren Jan , Schepens Tom , Mergeay Matthias , Janssen Luc , Hoogmartens Olivier , Neyrinck Arne , Marinus Benoît G. , Sabbe Marc
Published: April 2024

This study aims to resolve the unmet need for ventilator surge capacity by developing a prototype device that can alter patient-specific flow in a shared ventilator setup. The device is designed to deliver a predictable tidal volume (VT), requiring minimal additional monitoring and workload. The prototyped device was tested in an in vitro bench setup for its performance against the intended use and design criteria. The ventilation parameters: VT and airway pressures, and ventilation profiles: pressure, flow and volume were measured for different ventilator and device settings for a healthy and ARDS simulated lung pathology. We obtained VTs with a linear correlation with valve openings from 10 to 100% across set inspiratory pressures (IPs) of 20 to 30 cmH2O. Airway pressure varied with valve opening and lung elastance but did not exceed set IPs. Performance was consistent in both healthy and ARDS-simulated lung conditions. The ventilation profile diverged from traditional pressure-controlled profiles. We present the design a flow modulator to titrate VTs in a shared ventilator setup. Application of the flow modulator resulted in a characteristic flow profile that differs from pressure- or volume controlled ventilation. The development of the flow modulator enables further validation of the Individualized Shared Ventilation (ISV) technology with individualization of delivered VTs and the development of a clinical protocol facilitating its clinical use during a ventilator surge capacity problem.
Maximal cardiopulmonary exercise testing in glioblastoma patients undergoing chemotherapy: assessment of feasibility, safety, and physical fitness status
Authors: Jost Johanna , Völker Klaus , Brandt Ralf , Stummer Walter , Urbschat Steffi , Ketter Ralf , Wiewrodt Dorothee , Wiewrodt Rainer ,   for the MMH Trial Investigators, Kloss Maren , Hansel Nora , Früchte Irmtraud , Julian Ross , Thorwesten Lothar , Gerß Joachim , Faldum Andreas , Oertel Joachim , Lepper Philipp , Jetschke Kathleen , Rekowski Sylvia , Lucas Carolin Weiss , Kochs Sophia , Baumann Freerk
Published: April 2024

Purpose

Maximal cardiopulmonary exercise testing (max. CPET) provides the most accurate measurement of cardiorespiratory fitness. However, glioblastoma (GBM) patients often undergo less intensive tests, e.g., 6-min walk test or self-rating scales. This study aims to demonstrate feasibility and safety of max. CPET in GBM patients, concurrently evaluating their physical fitness status.

Methods

Newly diagnosed GBM patients undergoing adjuvant chemotherapy were offered participation in an exercise program. At baseline, max. CPET assessed cardiorespiratory fitness including peak oxygen consumption (VO2peak), peak workload, and physical work capacity (PWC) at 75% of age-adjusted maximal heart rate (HR). Criteria for peak workload were predefined based on threshold values in HR, respiratory quotient, respiratory equivalent, lactate, and rate of perceived effort. Data were compared to normative values. Adverse events were categorized according to standardized international criteria. Further, self-reported exercise data pre- and post-diagnosis were gathered.

Results

All 36 patients (median-aged 60; 21 men) met the predefined criteria for peak workload. Mean absolute VO2peak was 1750 ± 529 ml/min, peak workload averaged 130 ± 43 W, and mean PWC was 0.99 ± 0.38 W/kg BW, all clinically meaningful lower than age- and sex-predicted normative values (87%, 79%, 90%, resp.). Only once (3%) a minor, transient side effect occurred (post-test dizziness, no intervention needed). Self-reported exercise decreased from 15.8 MET-h/week pre-diagnosis to 7.2 MET-h/week post-diagnosis.

Conclusion

Max. CPET in this well-defined population proved feasible and safe. GBM patients exhibit reduced cardiorespiratory fitness, indicating the need for tailored exercise to enhance health and quality of life. CPET could be essential in establishing precise exercise guidelines.
Resolving the evolutionary paradox of consciousness
Authors: Zietsch Brendan P.
Published: April 2024

Evolutionary fitness threats and rewards are associated with subjectively unpleasant and pleasant sensations, respectively. Initially, these correlations appear explainable via adaptation by natural selection. But here I analyse the major metaphysical perspectives on consciousness – physicalism, dualism, and panpsychism – and conclude that none help to understand the adaptive-seeming correlations via adaptation. I also argue that a recently proposed explanation, the phenomenal powers view, has major problems that mean it cannot explain the adaptive-seeming correlations via adaptation either. So the mystery – call it the evolutionary paradox of consciousness – remains. Some have used this mystery to argue for non-naturalistic (e.g. theistic) explanations. But I propose a naturalistic, non-adaptive explanation of the adaptive-seeming correlations: namely, ‘sensational associative learning’ during development. In this perspective, pairing of particular sensations with unconditioned stimuli – fitness rewards or threats – cause the sensations themselves to come to be interpreted as good or bad, respectively. Sensations, like colours, that are not reliably paired with either fitness rewards or threats remain largely unvalenced. Sensational associative learning also provides explanations for adaptive-seeming structural aspects of sensations, such as the observation that sounds of different pitch are experienced as ordinal in correspondence to their wavelengths while the same is not true of colours of different hue. The sensational associative learning perspective appears compatible with physicalism, panpsychism, and dualism (though not epiphenomenalism).
Mind the gap: noncausal explanations of dual properties
Authors: Bangu Sorin
Published: April 2024

I identify and characterize a type of noncausal explanation in physics. I first introduce a distinction, between the physical properties of a system, and the representational properties of the mathematical expressions of the system’s physical properties. Then I introduce a novel kind of property, which I shall call a dual property. This is a special kind of representational property, one for which there is an interpretation as a physical property. It is these dual properties that, I claim, are amenable to noncausal (mathematical, in fact) explanations. I discuss a typical example of such a dual property, and an example of an explanation as to why that dual property holds (the explanation of the quantization of the linear momentum).
Structural topic modeling as a mixed methods research design: a study on employer size and labor market outcomes for vulnerable groups
Authors: Ulstein Julie
Published: April 2024

Obtaining and maintaining steady employment can be challenging for people from vulnerable groups. Previous research has focused on the relationship between employer size and employment outcomes for these groups, but the findings have been inconsistent. To clarify this relationship, the current study uses structural topic modeling, a mixed methods research design, to disclose and explain factors behind the association between employer size and labor market outcomes for people from vulnerable groups. The data consist of qualitative interview transcripts concerning the hiring and inclusion of people from vulnerable groups. These were quantitized and analyzed using structural topic modeling. The goals were to investigate topical content and prevalence according to employer size, to provide a comprehensive guide for model estimation and interpretation, and to highlight the wide applicability of this method in social science research. Model estimation resulted in a model with five topics: training, practicalities of the inclusion processes, recruitment, contexts of inclusion, and work demands. The analysis revealed that topical prevalence differed between employers according to size. Thus, these estimated topics can provide evidence as to why the association between employer size and labor market outcomes for vulnerable groups varies across studies––different employers highlight different aspects of work inclusion. The article further demonstrates the strengths and limitations of using structural topic modeling as a mixed methods research design.
The derivative-based approach to nonlinear mediation models: insights and applications
Authors: Di Maria Chiara , Rubino Claudio , Albano Alessandro
Published: April 2024

Traditional mediation analysis has been developed in the context of linear models, enabling the estimation of indirect effects through the product of regression coefficients. However, in the presence of nonlinearities, defining and estimating indirect effects becomes more challenging. While nonlinear mediation models are relatively easy to address in the counterfactual-based framework, very few generalizations to nonlinear associational settings have been proposed. One of the most intuitive is the derivative-based approach that, however, seems not to be widely spread among scholars. In this paper, we deepen such an approach to nonlinear mediation models, clarifying and proposing solutions to some issues which have not been addressed by the previous literature. Specifically, we discussed discrete exposures, binary mediators and extensions of this approach to more complex settings like the multilevel one. We also propose to estimate confidence intervals for the indirect effect within a Bayesian framework and compare its performance to that of other approaches in the literature through a simulation study. Finally, a real data application is presented.
Application of downhole throttling technology to mitigate sustained casing pressure
Authors: Wang Faqing , Qin Deyou , Zhang Bao , Wang Fangzhi , Zhong Ting , Shang Zhengkai , Cui Hangbo
Published: April 2024

Sustained casing pressure (SCP) and/or annular pressure build-up (APB) can pose severe threats to the safe operation of high-pressure, high-production gas wells, leading to premature well abandonment, unplanned workovers, significant production losses, and exorbitant detection costs. The techniques for addressing these issues broadly fall into two categories of rig-based and rig-less workovers. The rig-less workovers are the most cost-effective, outperforming surefooted rig-based workovers because there are many techniques for detecting downhole leaks, especially those utilizing rig-less data. As an established technique used elsewhere in the petroleum industry, downhole chokes have been proposed to mitigate SCP. However, some critical questions remain unanswered. For this reason and to facilitate field applicability, essential parameters, such as choke depth, are optimized in this work under various leaking circumstances in the tubing string. By using commercial software, the evolution of the annulus pressure with one single leak is analysed under the influences of certain parameters, such as leakage depth, casing pressure relief, production shifts, and initial gas column height in the tubing/casing annulus; then, the patterns of fluid exchange between the tubing and casing string and the annular pressure rise are investigated for two successive leaks. Finally, based on the resulting insights, the adaptability levels of downhole throttling technology for mitigating SCP are investigated under various scenarios with either single or double leaks. The results show that the key to success is to land below the leak for a single leak and below the lower leak for double leaks. The conclusions provide a low-cost, rigid measure for abating SCP.
Threatened and Priority listed Melaleuca species from Western Australia display high susceptibility to Austropuccinia psidii in controlled inoculations
Authors: Martino Alyssa M. , Park Robert F. , Tobias Peri A.
Published: April 2024

Austropuccinia psidii causes rust disease on species within the family Myrtaceae. It was first detected in Australia in 2010, with the first detection in Western Australia in 2022. While species within the genus Melaleuca from eastern Australia show variable responses to the pathogen, little is known of the response of species from Western Australia. This study established that 13 previously unscreened species of Melaleuca, including Threatened and Priority listed species that were grown from seeds sourced from Western Australian populations, were susceptible four months post-germination to the pandemic strain of the pathogen. The proportion of highly susceptible plants within a single species ranged from 2 to 94%, with several species displaying highly variable levels of resistance to A. psidii. These results highlight the importance of disease screening and may direct conservation efforts.
Microstructured Cantilever Probe on Optical Fiber Tip for Microforce Sensor
Authors: Wang Famei , Liao Changrui , Zou Mengqiang , Liu Dejun , Huang Haoqiang , Liu Chao , Wang Yiping
Published: April 2024

Benefiting from the great advances of the femtosecond laser two-photon polymerization (TPP) technology, customized microcantilever probes can be accurately 3-dimensional (3D) manufactured at the nanoscale size and thus have exhibited considerable potentials in the fields of microforce, micro-vibration, and microforce sensors. In this work, a controllable microstructured cantilever probe on an optical fiber tip for microforce detection is demonstrated both theoretically and experimentally. The static performances of the probe are firstly investigated based on the finite element method (FEM), which provides the basis for the structural design. The proposed cantilever probe is then 3D printed by means of the TPP technology. The experimental results show that the elastic constant k of the proposed cantilever probe can be actively tuned from 2.46 N/m to 62.35 N/m. The force sensitivity is 2.5 nm/µN, the Q-factor is 368.93, and the detection limit is 57.43 nN. Moreover, the mechanical properties of the cantilever probe can be flexibly adjusted by the geometric configuration of the cantilever. Thus, it has an enormous potential for matching the mechanical properties of biological samples in the direct contact mode.
Cognitive ability and the house money effect in public goods games
Authors: Hackinger Julian
Published: April 2024

I experimentally investigate the relation of endowment origin, cognitive abilities (as measured by the Cognitive Reflection Test, CRT), and co-operation in a one-shot linear public goods game. The results show that subjects’ contributions depend on an interplay of cognitive abilities and endowment origin. A house money effect exists only for subjects with low CRT scores. They contribute more when income was allocated to them and less when income was obtained by effort. In contrast, subjects with high CRT scores contribute the same amount independent of income type. The findings have implications for redistribution, team production, and experimental designs.
Tri-chalcogenides (Sb2S3/Bi2S3) solar cells with double electron transport layers: design and simulation
Authors: Saifee Md Amanullah , Latief Urosa , Ali Javid , Khan Mohd. Shahid
Published: April 2024

To make technology accessible to everyone, it is essential to focus on affordability and durability of the devices. Antimony trisulfide (Sb2S3) and bismuth (III) sulfide (Bi2S3) are low-cost and stable materials that are commonly used in photovoltaic devices due to their non-toxic nature and abundance. These materials are particularly promising for photovoltaic applications as they are effective light-absorbing materials. In this study, we utilized the Solar cell Capacitance Simulator- One-Dimensional (SCAPS-1D) software to investigate the parameters of a double electron transport layer (ETL) solar cell based on Sb2S3/ Bi2S3. The parameters examined included thickness of the absorber layer, overall defect density, density of acceptors, radiative recombination coefficient, series and shunt resistance, and work function of the back contact. The solar cell structure studied was FTO/SnO2/CdS/ Sb2S3 and Bi2S3/Spiro-OMeTAD/Au. By incorporating a SnO2 electron transport layer (ETL) into the double ETL structure of Sb2S3 and Bi2S3 solar cells, we observed a significant enhancement in the power conversion efficiency (PCE). Specifically, the PCE increased to 19.71% for the Sb2S3 solar cell and 24.05% for the Bi2S3 solar cell. In contrast, without SnO2, the single ETL-based CdS solar cell achieved a maximum PCE of 18.27 and 23.05% for Sb2S3 and Bi2S3, respectively.
Team science competencies for clinical research professionals: A multileveled Delphi approach
Authors: Mendell Angela , Fritter Jessica , Helm Shirley , Capili Bernadette , Hildreth Laura , Johnson Kathryn , Varnadoe Christa , Kopras Elizabeth , Sprecher Jen , Summerside Nicole , Carter Karen , Ronning Andrea , Exe Nicole , Kolb H. Robert , Jones Carolynn T.
Published: April 2024

Background:

The knowledge, skills, and abilities needed for clinical research professionals (CRPs) are described in the Joint Task Force (JTF) for Clinical Trial Competencies Framework as a basis for leveled educational programs, training curricula, and certification. There is a paucity of literature addressing team science competencies tailored to CRPs. Gaps in training, research, and education can restrict their capability to effectively contribute to team science.

Materials/Methods:

The CRP Team Science team consisted of 18 members from 7 clinical and translational science awarded institutions. We employed a multi-stage, modified Delphi approach to define “Smart Skills” and leveled team science skills examples using individual and team science competencies identified by Lotrecchiano et al.

Results:

Overall, 59 team science Smart Skills were identified resulting in 177 skills examples across three levels: fundamental, skilled, and advanced. Two examples of the leveled skillsets for individual and team competencies are illustrated. Two vignettes were created to illustrate application for training.

Discussion:

This work provides a first-ever application of team science for CRPs by defining specific individual and team science competencies for each level of the CRP career life course. This work will enhance the JTF Domains 7 (Leadership and Professionalism) and 8 (Communication and Teamwork) which are often lacking in CRP training programs. The supplement provides a full set of skills and examples from this work.

Conclusion:

Developing team science skills for CRPs may contribute to more effective collaborations across interdisciplinary clinical research teams. These skills may also improve research outcomes and stabilize the CRP workforce.
Taxonomies of exclusion: Storytelling, naming and classification in an age of extinction
Authors: Tabak Eline D.
Published: April 2024

Among the stories on individual examples of charismatic fauna, there are also extinction stories that evoke databases and their aesthetics in how they list endangered species. At the same time, these different stories grapple with a legacy of taxonomy that, while necessary in conservation, also carries a history of exclusion. This paper turns to the poetry of Claire Wahmanholm and Juliana Spahr to consider some of the ways extinction stories can be told outside of the relatively narrow scope of charismatic species. To begin, I reflect on extinction storytelling and the classificatory impulse in some of these stories, including poetry. Then, I consider scientific practices of naming before I turn back to Wahmanholm and Spahr and explore practices of naming and classification in their poetry. Following that, I dwell on the influence of scientific classification on the ways people including poets can engage with extinction. The poems in this paper are not merely an object for analysis; they should be considered an invitation to come to terms with and move beyond complicated histories and practices of naming and classification in storytelling.
Evaluation of autism awareness and knowledge levels among Syrian migrants living in Türkiye
Authors: Davun Selin , Sezerol Mehmet Akif
Published: April 2024

This study was conducted to evaluate the autism knowledge level and awareness of individuals over the age of 18 who applied to immigrant health centers in Istanbul, Gaziantep and Kilis, where the Syrian immigrant population is dense. This cross-sectional study was conducted between December 2022 and April 2023 in 896 immigrants. The sample of the research consists of immigrants residing in Türkiye and who applied to the immigrant health centers in Istanbul, Gaziantep and Kilis for any reason at the time of the research. A questionnaire consisting of three parts was applied to the immigrant people face-to-face. While 38.4% of the participants were female, 61.6% were male. The mean age of the participants is 34.63 ± 10.74. It was determined that people’s place of residence, whether they have children, marital status and income status have significant effects on autism knowledge levels (p < 0.001). Since the importance of early diagnosis in autism is known, it is of great importance for people to have knowledge and awareness on this issue. This study will investigate the awareness of the immigrant population, who are faced with traumatic events such as war and migration, and will shed light on future intervention studies.
High-energy laser facility PHELIX at GSI: latest advances and extended capabilities
Authors: Major Zs. , Eisenbarth U. , Zielbauer B. , Brabetz C. , Ohland J. B. , Zobus Y. , Roeder S. , Reemts D. , Kunzer S. , Götte S. , Neidherr D. , Hornung J. , Kewes P. , Schumacher D. , Beck D. , Hesselbach P. , Malki M. , Neumayer P. , Weyrich K. , Tauschwitz A. , Bagnoud V.
Published: April 2024

The high-energy/high-intensity laser facility PHELIX of the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt, Germany, has been in operation since 2008. Here, we review the current system performance, which is the result of continuous development and further improvement. Through its versatile frontend architecture, PHELIX can be operated in both long- and short-pulse modes, corresponding to ns-pulses with up to 1 kJ pulse energy and sub-ps, 200 J pulses, respectively. In the short-pulse mode, the excellent temporal contrast and the control over the wavefront make PHELIX an ideal driver for secondary sources of high-energy ions, neutrons, electrons and X-rays. The long-pulse mode is mainly used for plasma heating, which can then be probed by the heavy-ion beam of the linear accelerator of GSI. In addition, PHELIX can now be used to generate X-rays for studying exotic states of matter created by heavy-ion heating using the ion beam of the heavy-ion synchrotron of GSI.
Regular reflection of shock waves in steady flows: viscous and non-equilibrium effects
Authors: Bondar Y.A. , Shoev G.V. , Timokhin M.Y.
Published: April 2024

Numerical analysis of a steady monatomic gas flow about the point of the regular reflection of a strong oblique shock wave from the symmetry plane is conducted with the Navier–Stokes–Fourier (NSF) equations, the regularized Grad 13-moment (R13) equations and the direct simulation Monte Carlo (DSMC) method. In contrast to the inviscid solution to this problem completely defined by the Rankine–Hugoniot (RH) relations, all three models predict a complicated flow structure with strong thermal non-equilibrium and a long wake with flow parameters not predicted by the RH relations. The temperature

$T_y$

related to thermal motion of molecules in the direction normal to the symmetry plane has a maximum inside the reflection zone while in a planar shock wave the maximum is observed for the

$T_x$

temperature. The R13 equations predict these features much better than the NSF equations and are in good agreement with the benchmark DSMC results. An analysis of the flow with the conservation equations was conducted in order to evaluate the effects of various processes on a fluid element moving along the symmetry plane. In contrast to the shock wave where effects of viscosity and heat conduction are one-dimensional with zeroth net contribution to the fluid-element energy across the shock, the flow across the zone of the shock reflection is dominated by two-dimensional effects with positive net contribution of viscosity and negative contribution of heat conduction to the fluid-element energy. These effects are believed to be the main source of the wake with parameters deviating from the RH values.
Propagation instabilities of the oblique detonation wave in partially prevaporized n-heptane sprays
Authors: Tian Cheng , Teng Honghui , Shi Baolu , Yang Pengfei , Wang Kuanliang , Zhao Majie
Published: April 2024

Two-dimensional oblique detonation wave (ODW) propagations in partially prevaporized n-heptane sprays are numerically simulated with a skeletal chemical mechanism. The influences of the droplet diameter and total equivalence on oblique detonation are considered. The initiation length is found to increase first and then decrease with increasing initial droplet diameter, and the effect of droplet size is maximized when the initial droplet diameter is approximately

$10\ \mathrm {\mu } {\rm m}$

. As the initial droplet diameter varies, unsteady and steady ODWs are observed. In the cases of unsteady ODWs, temperature gradients and non-uniform distributions of the reactant mixture due to droplet evaporation lead to formation of unsteady detonation propagation, therefore leading to fluctuations in the initiation length. The fluctuations in initiation length decrease as the pre-evaporation gas equivalence ratio increases for the unsteady cases. The results further suggest that the relationship between the evaporation layer thickness along the streamline and the corresponding theoretical initiation length can be used to identify an unsteady or steady ODW in cases with large droplets that evaporate behind an oblique shock wave or ODW under the effects of different initial droplet diameters.
Hydrodynamic metamaterial redirector for steering fluid flow in pipelines with arbitrary curvatures
Authors: Pang Haixiang , You Yunxiang , Chen Ke
Published: April 2024

The dynamics of fluid-conveying pipelines with different shapes has received extensive research attention. Significant wall shear stress and flow separation occur when the fluid flows through pipelines with various curvatures. These phenomena trigger pipeline vibration, the generation of mechanical and hydrodynamic noise, damage, and even the rupture of the pipeline. However, previous studies have not considered the mechanism of internal pipeline flow to eliminate flow separation and the generation of secondary flow inside bent pipelines by redirecting and manipulating the flow. To steer the fluid flow, a ‘hydrodynamic transformation strategy’ based on the metamaterial technology is proposed for the first time in this work; through this strategy, the fluid in pipelines can be made to flow along trajectories that are always parallel to the central axis of the bent pipelines. Interestingly, this innovative method can effectively eliminate the elbow-induced secondary flow and prevent the generation of a pressure gradient toward the pipeline wall. Using the soft lithography technology or the three-dimensional printing technology, the hydrodynamic metamaterial microstructure required to manipulate the fluid flow path in actual engineering applications can be achieved. Our work paves the way for developing new approaches for controlling the flow characteristics and reducing the turbulence intensity of the fluid flowing in pipelines with elbows and corners.
Data-driven nonlinear turbulent flow scaling with Buckingham Pi variables
Authors: Fukami Kai , Goto Susumu , Taira Kunihiko
Published: April 2024

Nonlinear machine learning for turbulent flows can exhibit robust performance even outside the range of training data. This is achieved when machine-learning models can accommodate scale-invariant characteristics of turbulent flow structures. This study presents a data-driven approach to reveal scale-invariant vortical structures across Reynolds numbers that provide insights for supporting nonlinear machine-learning-based studies of turbulent flows. To uncover conditions for which nonlinear models are likely to perform well, we use a Buckingham-Pi-based sparse nonlinear scaling to find the influence of the Pi groups on the turbulent flow data. We consider nonlinear scalings of the invariants of the velocity gradient tensor for an example of three-dimensional decaying isotropic turbulence. The present scaling not only enables the identification of vortical structures that are interpolatory and extrapolatory for the given flow field data but also captures non-equilibrium effects of the energy cascade. As a demonstration, the present findings are applied to machine-learning-based super-resolution analysis of three-dimensional isotropic turbulence. We show that machine-learning models reconstruct vortical structures well in the interpolatory space with reduced performance in the extrapolatory space revealed by the nonlinearly scaled invariants. The present approach enables us to depart from labelling turbulent flow data with a single parameter of Reynolds number and comprehensively examine the flow field to support training and testing of nonlinear machine-learning techniques.
A PINN approach for identifying governing parameters of noisy thermoacoustic systems
Authors: Son Hwijae , Lee Minwoo
Published: April 2024

Identifying the governing parameters of self-sustained oscillation is crucial for the diagnosis, prediction and control of thermoacoustic instabilities. In this paper, we propose and validate a novel method for computing the parameters of thermoacoustic oscillation in a stochastic environment, which exploits a physics-informed neural network (PINN). Specifically, we introduce a negative log-likelihood loss function that integrates the stochastic samples and the solution of the Fokker–Planck equation. The proposed framework is validated using the numerically generated signal and the experimental data obtained from an annular combustor, both before and after the supercritical Hopf bifurcation. The results of PINN-based system identification show good agreement with the actual system parameters and the original stochastic signal, with improved accuracy compared to established methods. To the best of our knowledge, this study constitutes the first demonstration of the PINN-inverse approach that uses the noise-induced dynamics of thermoacoustic systems, opening up new pathways for diagnosing and predicting the thermoacoustic behaviour of various combustion systems.
Diffusive-convection staircases in the polar oceans: the interplay between double diffusion and turbulence
Authors: Ma Yuchen , Peltier W.R.
Published: April 2024

Numerical simulations have been conducted to examine the structure of diffusive-convection staircases in the presence of vortical-mode-induced turbulent forcing. By modulating the input power

$P$

and the background density ratio

$R_\rho$

, we have identified three distinct types of staircase structures in these simulations: namely staircases maintained in the system driven by double-diffusion, by turbulence or by a combination of both double-diffusion and turbulence. While we showed that staircases maintained in the double-diffusion-dominated system are accurately characterised by the existing model originally proposed by Linden & Shirtcliffe (J. Fluid Mech., vol. 87, no. 3, 1978, pp. 417–432), we introduced new physical models to describe the staircase structures maintained in the turbulence-dominated system and the system driven by both turbulence and double-diffusion. Our integrated model reveals that turbulence fundamentally governs the entire life cycle of the diffusive-convection staircases, encompassing their formation, maintenance and eventual disruption in the Arctic Ocean's thermohaline staircases. While our previous work of Ma & Peltier (J. Fluid Mech., vol. 931, 2022b) demonstrated that turbulence could initiate the formation of Arctic staircases, these staircases are sustained by both turbulence and double-diffusion acting together after formation has occurred. Strong turbulence may disrupt staircase structures; however, the presence of weak turbulence could lead to unstable stratification within mixed layers of the staircases, as well as enhancing vertical heat and salt fluxes. Turbulence can even sustain a stable staircase structure factor when

$R_\rho$

is relatively large, following a similar mechanism to the density staircases observed in laboratory experiments. Consequently, previous parameterisations (e.g. Kelley, J. Geophys. Res.: Oceans, vol. 95, no. C3, 1990, pp. 3365–3371) on the vertical heat flux across the diffusive-convection staircases may provide a significant underestimation of the heat transport by ignoring the influences of turbulence.
Spatial growth rates of young wind waves under steady wind forcing
Authors: Kumar Krishanu , Shemer Lev
Published: April 2024

The growth with fetch of young wind waves under steady wind forcing that is commonly attributed to shear flow instability results in a spatially inhomogeneous wave field with a spectrum evolving along the tank. The present laboratory study accounts for multiple co-existing statistically stationary random frequency harmonics. Single-point synchronous measurements of the instantaneous surface elevation and of its along-wind slope component are performed by optical methods at numerous locations. Assuming exponential spatial growth, the phase shift between the surface elevation and surface slope at each frequency is related to the spatial growth rate of each harmonic. The validity of the assumption that the wave energy varies exponentially with fetch is examined in a separate set of experiments; the instantaneous surface elevation at various wind-forcing conditions is measured at multiple locations along the tank. The spatial variation of the energy of individual frequency harmonics is determined. It is found that, below the local peak frequency, the energy of each harmonic grows exponentially, while the evolution of waves at frequencies approaching and exceeding the local peak is strongly affected by sheltering by the dominant wave, as well as by nonlinear bound waves. The outcomes of two independent methods of determination of spatial growth rates at a range of young wave frequencies are compared. The accumulated data also enable quantitative analysis of the sheltering phenomenon. The essential difference between the spatial and the temporal wind-wave evolution cases is discussed.
WHEN IS THE SILTING-DISCRETENESS INHERITED?
Authors: AIHARA TAKUMA , HONMA TAKAHIRO
Published: April 2024

We explore when the silting-discreteness is inherited. As a result, one obtains that taking idempotent truncations and homological epimorphisms of algebras transmit the silting-discreteness. We also study classification of silting-discrete simply-connected tensor algebras and silting-indiscrete self-injective Nakayama algebras. This paper contains two appendices; one states that every derived-discrete algebra is silting-discrete, and the other is about triangulated categories whose silting objects are tilting.
Classification of compact radio sources in the Galactic plane with supervised machine learning
Authors: Riggi S. , Umana G. , Trigilio C. , Bordiu C. , Bufano F. , Ingallinera A. , Cavallaro F. , Gordon Y. , Norris R.P. , Gürkan G. , Leto P. , Buemi C. , Loru S. , Hopkins A.M. , Filipović M.D. , Cecconello T.
Published: April 2024

Generation of science-ready data from processed data products is one of the major challenges in next-generation radio continuum surveys with the Square Kilometre Array (SKA) and its precursors, due to the expected data volume and the need to achieve a high degree of automated processing. Source extraction, characterization, and classification are the major stages involved in this process. In this work we focus on the classification of compact radio sources in the Galactic plane using both radio and infrared images as inputs. To this aim, we produced a curated dataset of$\sim$20 000 images of compact sources of different astronomical classes, obtained from past radio and infrared surveys, and novel radio data from pilot surveys carried out with the Australian SKA Pathfinder. Radio spectral index information was also obtained for a subset of the data. We then trained two different classifiers on the produced dataset. The first model uses gradient-boosted decision trees and is trained on a set of pre-computed features derived from the data, which include radio-infrared colour indices and the radio spectral index. The second model is trained directly on multi-channel images, employing convolutional neural networks. Using a completely supervised procedure, we obtained a high classification accuracy (F1-score > 90%) for separating Galactic objects from the extragalactic background. Individual class discrimination performances, ranging from 60% to 75%, increased by 10% when adding far-infrared and spectral index information, with extragalactic objects, PNe and Hiiregions identified with higher accuracies. The implemented tools and trained models were publicly released and made available to the radioastronomical community for future application on new radio data.
On the reconstruction of unknown driving forces from low-mode observations in the 2D Navier–Stokes equations
Authors: Martinez Vincent R.
Published: April 2024

This article is concerned with the problem of determining an unknown source of non-potential, external time-dependent perturbations of an incompressible fluid from large-scale observations on the flow field. A relaxation-based approach is proposed for accomplishing this, which makes use of a nonlinear property of the equations of motions to asymptotically enslave small scales to large scales. In particular, an algorithm is introduced that systematically produces approximations of the flow field on the unobserved scales in order to generate an approximation to the unknown force; the process is then repeated to generate an improved approximation of the unobserved scales, and so on. A mathematical proof of convergence of this algorithm is established in the context of the two-dimensional Navier–Stokes equations with periodic boundary conditions under the assumption that the force belongs to the observational subspace of phase space; at each stage in the algorithm, it is shown that the model error, represented as the difference between the approximating and true force, asymptotically decreases to zero in a geometric fashion provided that sufficiently many scales are observed and certain parameters of the algorithm are appropriately tuned.
Paleoclimate Proxies and the Benefits of Disunity
Authors: Watkins Aja
Published: April 2024

Measuring the climates of the deep past requires the use of paleoclimate proxies. I describe two proxy data and measurement practices, regarding proxy calibration and proxy data infrastructure. I document how at least some data and measurement practices in paleoclimatology are disunified: these practices do not involve intercalibration or otherwise statistical combination of multiple proxy records, and metadata necessary for proxy data to be reused or intercompared is often not provided. I argue that, perhaps counterintuitively, this lack of standardization and unification of proxy data and measurements has several benefits, especially related to the management of error and uncertainty.
Titratable residues that drive RND efflux: Insights from molecular simulations
Authors: Clark Robert , Newman Kahlan E. , Khalid Syma
Published: April 2024

The resistance–nodulation–division efflux machinery confers antimicrobial resistance to Gram-negative bacteria by actively pumping antibiotics out of the cell. The protein complex is powered by proton motive force; however, the proton transfer mechanism itself and indeed even its stoichiometry is still unclear. Here we review computational studies from the last decade that focus on elucidating the number of protons transferred per conformational cycle of the pump. Given the difficulties in studying proton movement using even state-of-the-art structural biology methods, the contributions from computational studies have been invaluable from a mechanistic perspective.
CHARACTERISATION OF PRIMES DIVIDING THE INDEX OF A CLASS OF POLYNOMIALS AND ITS APPLICATIONS
Authors: JAKHAR ANUJ
Published: April 2024

Let
${\mathbb {Z}}_{K}$
denote the ring of algebraic integers of an algebraic number field
$K = {\mathbb Q}(\theta )$
, where
$\theta $
is a root of a monic irreducible polynomial
$f(x) = x^n + a(bx+c)^m \in {\mathbb {Z}}[x]$
,
$1\leq m<n$
. We say
$f(x)$
is monogenic if
$\{1, \theta , \ldots , \theta ^{n-1}\}$
is a basis for
${\mathbb {Z}}_K$
. We give necessary and sufficient conditions involving only
$a, b, c, m, n$
for
$f(x)$
to be monogenic. Moreover, we characterise all the primes dividing the index of the subgroup
${\mathbb {Z}}[\theta ]$
in
${\mathbb {Z}}_K$
. As an application, we also provide a class of monogenic polynomials having non square-free discriminant and Galois group
$S_n$
, the symmetric group on n letters.
Application of computer vision and deep learning models to automatically classify medically important mosquitoes in North Borneo, Malaysia
Authors: Ong Song-Quan , Ab Majid Abdul Hafiz , Li Wei-Jun , Wang Jian-Guo
Published: April 2024

Mosquito-borne diseases have emerged in North Borneo in Malaysia due to rapid changes in the forest landscape, and mosquito surveillance is key to understanding disease transmission. However, surveillance programmes involving sampling and taxonomic identification require well-trained personnel, are time-consuming and labour-intensive. In this study, we aim to use a deep leaning model (DL) to develop an application capable of automatically detecting mosquito vectors collected from urban and suburban areas in North Borneo, Malaysia. Specifically, a DL model called MobileNetV2 was developed using a total of 4880 images of Aedes aegypti, Aedes albopictus and Culex quinquefasciatus mosquitoes, which are widely distributed in Malaysia. More importantly, the model was deployed as an application that can be used in the field. The model was fine-tuned with hyperparameters of learning rate 0.0001, 0.0005, 0.001, 0.01 and the performance of the model was tested for accuracy, precision, recall and F1 score. Inference time was also considered during development to assess the feasibility of the model as an app in the real world. The model showed an accuracy of at least 97%, a precision of 96% and a recall of 97% on the test set. When used as an app in the field to detect mosquitoes with the elements of different background environments, the model was able to achieve an accuracy of 76% with an inference time of 47.33 ms. Our result demonstrates the practicality of computer vision and DL in the real world of vector and pest surveillance programmes. In the future, more image data and robust DL architecture can be explored to improve the prediction result.
Recovering the Dalit Public Sphere: Vernacular Liberalism in Late Colonial North India
Authors: Rawat Ramnarayan S.
Published: April 2024

Drawing from publications by Swami Achutanand and the Adi-Hindu Mahasabha press between 1916 and 1940, this article examines the role of this north Indian Dalit organization in creating language and categories of liberalism in the Hindi vernacular. The Mahasabha poet-activists published numerous song-booklets in a variety of Hindi song genres to intervene in ongoing discussions on the subjects of representation and equality which they characterized as mulki-haq and unch-niche. Histories of liberties in late colonial India have typically examined its emergence within dominant Hindu and Muslim middle-class groups. This article uncovers the unique contributions of Dalit poet-activists who recognized the value of liberal ideas and institutions in challenging caste and abolishing “Manu’s Kanun” (lawgiver Manu’s Hindu law codes). It highlights the methodological importance of mohalla (neighborhood) sources usually located in Dalit activists’ houses in untouchable quarters. The chapbooks found in mohalla collections have enabled the writing of a new history of the Mahasabha’s activism and of the initiatives taken by poet-activists in founding a new Dalit politics in northern India. I explore the emergence of a Dalit literate public which sustained the activities of the Mahasabha and which responded with enthusiasm to its articulation of the new social identity of Achut (untouched) and a new political identity of Adi-Hindus—original inhabitants of Hindustan (India). Offering a new methodological approach in using mohalla sources and song-booklets composed in praise of liberal institutions, this essay makes a significant contribution to the recovery of a forgotten Dalit public sphere in early twentieth-century India.
Of Rule not Revenue: South Sudan’s Revenue Complex from Colonial, Rebel, to Independent Rule, 1899 to 2023
Authors: Benson Matthew Sterling
Published: April 2024

This article analyses taxation practices in colonial, post-colonial rebel-led, and independent South Sudan and argues that the ethos of taxation in the region has been and remains primarily oriented around predatory and coercive strategies of rule. This overarching pattern endures because the fundamental structure and rationale of revenue-raising practices, which collectively constitute South Sudan’s revenue complex, have not changed since at least Anglo-Egyptian occupation of the region in 1899. The paper explains how tax collecting as predation began when the first colonial administration deployed taxes to acquire loyalty from customary authorities such as chiefs and sheikhs, who personally benefitted from their taxation powers. From the early 1960s to 2005, armed groups in the region periodically fought against Khartoum-led rule, and rebels extorted taxes from the population to help fuel their war efforts. Taxes in today’s South Sudan, which acquired independence in 2011, are not collected to raise revenue except to pay off the individuals collecting them, and they continue to generate predation. The rise of international aid and windfalls from oil revenues have further diminished taxation’s financial significance for the national government and have altered local authorities’ coercive demands for payment. The portrait that emerges from the practices of South Sudan’s successive war-makers and state-makers is one of taxation wielded as a technology of rule, one of coercion and often extortion, to fulfil the self-interests of tax collectors. The article is based on archival research in Sudanese and South Sudanese national archives, British colonial archives, and 205 interviews conducted in South Sudan.
Gender, Competition, and Performance: International Evidence
Authors: Li Kai , Peng Qiyuan , Shen Rui , Wong Gabriel
Published: April 2024

Using a hand-collected sample of 18,269 equity analysts from 42 countries over the period of 2004 to 2019, we establish an intriguing negative association between a country’s institutional/economic development and its female share of equity analysts. We show that, in individualistic countries only, there is no gender gap in analyst forecast accuracy. We further show that female analysts are more skilled and more likely to drop out when underperforming in individualistic countries compared to peers in collectivistic countries. The evidence supports our hypothesis that the national cultural value of individualism encourages women to make career choices consistent with their general aversion to competition.