bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical simulation of three dimensional concrete printing based on a unified fluid and solid mechanics formulation
Authors: Reinold Janis , Daadouch Koussay , Meschke Günther
Published: May 2024

Deformation control constitutes one of the main technological challenges in three dimensional (3D) concrete printing, and it presents a challenge that must be addressed to achieve a precise and reliable construction process. Model-based information of the expected deformations and stresses is required to optimize the construction process in association with the specific properties of the concrete mix. In this work, a novel thermodynamically consistent finite strain constitutive model for fresh and early-age 3D-printable concrete is proposed. The model is then used to simulate the 3D concrete printing process to assess layer shapes, deformations, forces acting on substrate layers and prognoses of possible structural collapse during the layer-by-layer buildup. The constitutive formulation is based on a multiplicative split of the deformation gradient into elastic, aging and viscoplastic parts, in combination with a hyperelastic potential and considering evolving material properties to account for structural buildup or aging. One advantage of this model is the stress-update-scheme, which is similar to that of small strain plasticity and therefore enables an efficient integration with existing material routines. The constitutive model uses the particle finite element method, which serves as the simulation framework, allowing for modeling of the evolving free surfaces during the extrusion process. Computational analyses of three printed layers are used to create deformation plots, which can then be used to control the deformations during 3D concrete printing. This study offers further investigations, on the structural level, focusing on the potential structural collapse of a 3D printed concrete wall. The capability of the proposed model to simulate 3D concrete printing processes across the scales—from a few printed layers to the scale of the whole printed structure—in a unified fashion with one constitutive formulation, is demonstrated.
Effects of immune cells in mediating the relationship between gut microbiota and myelodysplastic syndrome: a bidirectional two-sample, two-step Mendelian randomization study
Authors: Feng Zuxi , Liao Minjing , Guo Xuege , Li Lijuan , Zhang Liansheng
Published: May 2024

Background

The definitive establishment of a causal relationship between gut microbiota and myelodysplastic syndrome (MDS) has not been achieved. Furthermore, the involvement of immune cells in mediating the connection between gut microbiota and MDS is presently unclear.

Methods

To elucidate the bidirectional correlation between gut microbiota and MDS, as well as to investigate the mediating role of immune cells, a bidirectional two-sample, two-step Mendelian randomization (MR) study was conducted. Summary statistics were obtained from genome-wide association studies (GWAS), including MDS (456,348 individuals), gut microbiota (18,340 individuals), and 731 immune cells signatures (3757 individuals).

Results

Genetically predicted eight gut microbiota traits were significantly associated with MDS risk, but not vice versa. Through biological annotation of host-microbiome shared genes, we found that immune regulation may mediate the impact of gut microbiota on MDS. Subsequently, twenty-three immunophenotypes that exhibited significant associations with MDS risk and five of these immunophenotypes were under the causal influence of gut microbiota. Importantly, the causal effects of gut microbiota on MDS were significantly mediated by five immunophenotypes, including CD4 +T cell %leukocyte, CD127 on CD45RA − CD4 not regulatory T cell, CD45 on CD33 + HLA DR + WHR, CD33 on basophil, and Monocyte AC.

Conclusions

Gut microbiota was causally associated with MDS risk, and five specific immunophenotypes served as potential causal mediators of the effect of gut microbiota on MDS. Understanding the causality among gut microbiota, immune cells and MDS is critical in identifying potential targets for diagnosis and treatment.
A Quantitative Comparison of Patterns of Play and Conflict in Nature Preschool and Traditional Preschool Children in Norway
Authors: Nguyen Nga , Fashing Peter J. , Trosvik Pål , Stenseth Nils Chr. , de Muinck Eric J.
Published: May 2024

Early childhood experiences have lifelong physical, social, emotional, and cognitive impacts. High quality early childhood education and care (ECEC) can put children on the path to personal development, lifelong learning, and future employability. Among the fastest growing ECEC options are nature-based preschools, where children spend most or all of each day outdoors in natural environments, but comparative studies of children’s behavior in nature-based versus traditional preschools are needed. We conducted an observational study comparing conflict, activity patterns, and play behavior among children at a nature preschool and a traditional preschool, both in Norway, where access to high quality ECEC is a universal right. We found that preschool children’s behavior varied with time spent outdoors in natural environments: (1) play was more physically active, less gendered, and less often incorporated human-made items at the nature preschool, (2) conflict was almost twice as common at the traditional preschool, and (3) daily group activities at the traditional preschool like sitting down to a cooked meal and gathering up and putting away toys were absent from the nature preschool. While both the traditional and nature preschools offered children equal amounts of play time and a variety of physically and socially stimulating play activities, our results suggest that access to natural environments impacts preschool children’s behavior and interactions in meaningful ways.
SPINDILOMETER: a model describing sleep spindles on EEG signals for polysomnography
Authors: Kayabekir Murat , Yağanoğlu Mete
Published: May 2024

This paper aims to present a model called SPINDILOMETER, which we propose to be integrated into polysomnography (PSG) devices for researchers focused on electrophysiological signals in PSG, physicians, and technicians practicing sleep in clinics, by examining the methods of the sleep electroencephalogram (EEG) signal analysis in recent years. For this purpose, an assist diagnostic model for PSG has been developed that measures the number and density of sleep spindles by analyzing EEG signals in PSG. EEG signals of 72 volunteers, 51 males and 21 females (age; 51.7 ± 3.42 years and body mass index; 37.6 ± 4.21) diagnosed with sleep-disordered breathing by PSG were analyzed by machine learning methods. The number and density of sleep spindles were compared between the classical method (EEG monitoring with the naked eye in PSG) (‘method with naked eye’) and the model (SPINDILOMETER). A strong positive correlation was found between ‘method with naked eye’ and SPINDILOMETER results (correlation coefficient: 0.987), and this correlation was statistically significant (p = 0.000). Confusion matrix (accuracy (94.61%), sensitivity (94.61%), specificity (96.60%)), and ROC analysis (AUC: 0.95) were performed to prove the adequacy of SPINDILOMETER (p = 0.000). In conclusion SPINDILOMETER can be included in PSG analysis performed in sleep laboratories. At the same time, this model provides diagnostic convenience to the physician in understanding the neurological events associated with sleep spindles and sheds light on research for thalamocortical regions in the fields of neurophysiology and electrophysiology.
Failure characteristics and fracture mechanism of overburden rock induced by mining: A case study in China
Authors: Li Jiawei , Zhang Meng , Wang Changxiang , Liao Changlong , Zhang Baoliang
Published: May 2024

This study employs similar simulation testing and discrete element simulation coupling to analyze the failure and deformation processes of a model coal seam's roof. The caving area of the overburden rock is divided into three zones: the delamination fracture zone, broken fracture zone, and compaction zone. The caving and fracture zones' heights are approximately 110 m above the coal seam, with a maximum subsidence of 11 m. The delamination fracture zone's porosity range is between 0.2 and 0.3, while the remainder of the roof predominantly exhibits a porosity of less than 0.1. In addition, the numerical model's stress analysis revealed that the overburden rock's displacement zone forms an 'arch-beam' structure starting from 160 m, with the maximum and minimum stress values decreasing as the distance of advancement increases. In the stress beam interval of the overburden rock, the maximum value changes periodically as the advancement distance increases. Based on a comparative analysis between observable data from on-site work and numerical simulation results, the stress data from the numerical simulation are essentially consistent with the actual results detected on-site, indicating the validity of the numerical simulation results.
Comparative study on different coals from the Lorraine basin (France) by sorption isotherms, thermogravimetric analysis and breakthrough curves for CO2-ECBM recovery
Authors: Amoih Franck , Finqueneisel Gisèle , Zimny Thierry , Bourrelly Sandrine , Barres Odile , Grgic Dragan
Published: May 2024

The enhanced coalbed methane recovery using CO2 injection (CO2-ECBM) is widely proposed as a way of achieving the energy transition and reducing atmospheric CO2 in areas such as the Lorrain basin in France, where heavy industry is responsible for huge CO2 emissions and coal mines have been closed for more than a decade. This paper deals with the feasibility of extracting methane from the Lorraine basin using CO2-ECBM by comparing data from sorption isotherms, thermogravimetric analyses and breakthrough curves for two coal samples. One is bituminous (Box 18), from Folschviller (France) and is compared with another sub-bituminous (TH01) from La Houve (France), which is used as a reference because it was identified as a good candidate for CO2-ECBM in a previous research program. The quantities of adsorbed gases (CO2/CH4) obtained by sorption isotherms, thermogravimetry and CO2 breakthrough curves showed that Box 18 adsorbs more CO2 and CH4 than TH01 due to its higher porosity and good affinity for gases (CO2/CH4). Tόth model fits the experimental CH4 and CO2 adsorption isotherms better, reflecting the fact that the adsorption surface of the coals studied is heterogeneous. Adsorption enthalpies obtained by calorimetry indicated physisorption for gas-coal interactions, with higher values for CO2 than for CH4. Thermogravimetric analyses and breakthrough curves carried out at up to 50% relative humidity showed that the adsorption capacity of CO2 decreases with increasing temperature and the presence of water, respectively. The compilation of these experimental data explained the adsorption process of the studied coals and revealed their advantages for CO2-ECBM.
Standardisation efforts of ISO/TC 261 “additive manufacturing” 23rd plenary meeting of ISO/TC 261 “additive manufacturing”
Authors: Pei Eujin , Lakomiec Marius
Published: May 2024

The main objective of ISO/TC 261 is to standardise the processes of Additive Manufacturing, the process chains (Data, Materials, Processes, Hard- and Software, Applications), test procedures, quality parameters, supply agreements, environment, health and safety, fundamentals and vocabularies. This section provides readers with news regarding standardisation efforts of ISO/TC 261. Further up-to-date information regarding recently published documents, such as new standards, revised standards, and the status of standards, can be found in the ISO/TC261 webpages: https://www.iso.org/committee/629086.html and from the committee webpages: https://committee.iso.org/sites/tc261/home/news.html.
Relative Age Effects and the Premier League’s Elite Player Performance Plan (EPPP): A Comparison of Birthdate Distributions Within and Between Age Groups
Authors: Doncaster Greg , Kelly Adam L. , McAuley Alexander B. T. , Cain Andrew , Partington Mark , Nelson Lee , O’Gorman Jimmy
Published: May 2024

The purpose of this study was to investigate the prevalence of relative age effects (RAEs) within and between U18, U21 and professional senior squads, that compete in the highest (respective) leagues within England. Birthdate, playing position and age (years) of U18 (n = 487), U21 (n = 350), and senior (n = 396) players from squads competing in the highest divisions of their respective age groups were obtained. Moreover, nationality (UK or Non-UK) was recorded for U21 and senior players, with estimated market value also obtained for senior players. Chi-square tests, Cramer’s V and odds ratios with 95% confidence intervals were used to compare observed and expected birthdate distributions. A selection bias toward relatively older players was evident within U18 and U21 squads, across all positions. Furthermore, analysis of age bands within each age group also revealed an increase in the prevalence of RAEs throughout each age group. In contrast, analysis of senior squads revealed no significant deviations in birthdate distributions when considered as a whole sample, as separate age bands or by position. However, although non-significant, Q4 players were found to have the highest estimated market value. Results demonstrate RAEs are prevalent across U18 and U21 age groups at the highest level of competitive football within England, yet this is not representative of the birthdate distributions within senior squads. Ongoing research is needed to highlight the prevalence of RAEs within academies, particularly when these RAEs are not representative of birthdate distributions within professional senior squads.
Toward Efficient Legislative Processes: Analysis of Chilean Congressional Bill Votes Using Semantic Web Technologies
Authors: Cifuentes-Silva Francisco , Astudillo Hernán , Gayo José Emilio Labra , Rivera-Polo Felipe
Published: May 2024

Between 1990 and 2023, Chile’s Congress processed and approved 2738 laws, with an average processing time of 667.8 days from proposal to official publication. Recent political circumstances have underscored the need to identify legislative proposals that can be expedited for approval and which ones are unlikely to be approved at all. This article describes a bottom-up, data-driven classification of voting (and voters) on law proposals, which yield two axis: polarization (lack of agreement on an issue), and (political) alignment (intra-party coincidence of a group’s members regarding certain opinion). And four quadrants: “ideological stance” (high polarization, high alignment), “personal interests” (high polarization, low alignment), “thematic interest” (low polarization, low alignment), and “technical consensus” (low polarization, high alignment). We used this scheme to analyze an existing Open Linked Dataset with semantic web technologies (ontologies, RDF Shape expressions, and URI patterns), which records parliamentarians’ political parties and their voting on law proposals during 1990–2023. We found that most bills (70.14%) are in the technical consensus quadrant, and could have been quickly shepherded to approval. Wider adoption of this analysis to classify new bills may help to speed up their legislative processing, ultimately allowing Congress to serve citizens in a more timely manner.
James Buchanan and Peaceful Cooperation
Authors: Marciano Alain
Published: May 2024

Buchanan believed that individuals are fundamentally willing to cooperate with others. It was at the center of his works in public finance in the late 1940s and early 1950s, and also crucial to his work in public choice in the 1960s. The purpose of this book is to show which forms this belief took over these two decades or so, and to explain the continuity between these forms. We adopt a historical approach that allows us to recount the story of how Buchanan came to develop a theory of collective action, including his conception of cooperation in small groups, to implement a technical condition about the pricing of public goods he defended early in his career. We describe the different steps Buchanan took, the encounters that influenced him, and the events and challenges that led him to revise his views to make room for this fundamental philosophical conviction.
Optimal experiment design with adjoint-accelerated Bayesian inference
Authors: Yoko Matthew , Juniper Matthew P.
Published: May 2024

We develop and demonstrate a computationally cheap framework to identify optimal experiments for Bayesian inference of physics-based models. We develop the metrics (i) to identify optimal experiments to infer the unknown parameters of a physics-based model, (ii) to identify optimal sensor placements for parameter inference, and (iii) to identify optimal experiments to perform Bayesian model selection. We demonstrate the framework on thermoacoustic instability, which is an industrially relevant problem in aerospace propulsion, where experiments can be prohibitively expensive. By using an existing densely sampled dataset, we identify the most informative experiments and use them to train the physics-based model. The remaining data are used for validation. We show that, although approximate, the proposed framework can significantly reduce the number of experiments required to perform the three inference tasks we have studied. For example, we show that for task (i), we can achieve an acceptable model fit using just 2.5% of the data that were originally collected.
A two-year longitudinal evaluation of the impact of the COVID-19 pandemic on pre-existing mental health service attenders
Authors: O’Gorman E. , Rainford A. , Devaney E. , O’Mahony B. , McLoughlin J. , Hallahan B.
Published: May 2024

Background:

To examine if the COVID-19 pandemic was associated with a differential effect longitudinally in relation to its psychological and functional impact on patients with bipolar disorder and Emotionally Unstable Personality Disorder (EUPD).

Methods:

Semi-structured interviews were conducted with 29 individuals attending the Galway-Roscommon Mental Health Services with an ICD-10 diagnosis of either bipolar disorder (n = 18) or EUPD (n = 11). The impact of the COVID-19 pandemic was assessed in relation to anxiety and mood symptoms, social and occupational functioning, and quality of life utilising psychometric instruments and Likert scale data, with qualitative data assessing participants’ subjective experiences.

Results:

Individuals with EUPD exhibited significant anxiety and depressive symptoms and increased hopelessness compared to individuals with bipolar disorder. Repeated measures data demonstrated no significant change in symptomatology for either the EUPD or bipolar disorder group over time, but demonstrated an improvement in social (t = 4.40, p < 0.001) and occupational functioning (t = 3.65, p = 0.03), and in quality of life (t = 4.03, p < 0.001) for both participant groups. Themes attained from qualitative data included the positive impact of the discontinuation of COVID-19 mandated restrictions (n = 19), and difficulties experienced secondary to reductions in the provision of mental health services during the COVID-19 pandemic (n = 17).

Conclusion:

Individuals with EUPD demonstrated increased symptomatology over a two-year period compared to those with bipolar disorder. The importance of face-to-face mental health supports for this cohort are indicated, particularly if future pandemics impact the delivery of mental health services.
Wall skin friction analysis in a hypersonic turbulent boundary layer over a compression ramp
Authors: Guo Tongbiao , Zhang Ji , Zhu Yanhua , Li Xinliang
Published: May 2024

In this paper, direct numerical simulations in hypersonic turbulent boundary layers over a

$24^{\circ }$

compression ramp at Mach 6.0 are performed. The wall skin friction and its spanwise non-homogeneity in the interaction region are analysed via the spectral analysis and drag decomposition method. On the compression ramp, the premultiplied spanwise energy spectrum of wall shear stress

$\tau _{w}$

reveals two energetic spanwise length scales. One occurs in the region of

$x/\delta _{ref}=0\unicode{x2013}3$

(

$x=0$

lies in the compression corner;

$\delta _{ref}$

is the boundary layer thickness upstream of the interaction region) and is consistent with that of the large-scale streamwise vortices, indicating that the fluctuation intensity of

$\tau _{w}$

is associated with the Görtler-type structures. The other one is observed downstream of

$x/\delta _{ref}=3.0$

and corresponds to the regenerated elongated streaky structures. The fluctuation intensity of

$\tau _{w}$

peaks at

$x/\delta _{ref}=3.0$

, where both the above energetic length scales are observed. The drag decomposition method proposed by Li et al. (J. Fluid Mech., vol. 875, 2019, pp. 101–123) is extended to include the effects of spanwise non-homogeneity so that it can be used in the interaction region where the mean flow field and the mean skin friction

$C_f$

exhibit an obvious spanwise heterogeneity. The results reveal that, in the upstream turbulent boundary layer, the drag contribution arising from the spanwise heterogeneity can be neglected, while this value on the compression ramp is up to 20.7 % of

$C_f$

, resulting from the Görtler-type vortices. With the aid of the drag decomposition method, it is found that the main flow features that contribute positively to the amplification of

$C_f$

and its rapid increase on the compression ramp includes: the density increase across the shock, the high mean shear stress and turbulence amplification around the detached shear layer and the Favre-averaged downward velocity towards the ramp wall. Compared with the spanwise-averaged value,

$C_f$

and its components at the spanwise station where the downwash and upwash of the Görtler-type vortices occur reveal a spanwise variation exceeding 10 %.
On the dynamics of aligned inertial particles settling in a quiescent, stratified two-layer medium
Authors: Kang Soohyeon , Best James L. , Chamorro Leonardo P.
Published: May 2024

We explored the settling dynamics of vertically aligned particles in a quiescent, stratified two-layer fluid using particle tracking velocimetry. Glass spheres of

$d=4\,{\rm mm}$

diameter were released at frequencies of 4, 6 and 8 Hz near the free surface, traversing through an upper ethanol layer (

$H_1$

), where H is height or layer thickess, varying from

$10d$

to

$40d$

and a lower oil layer. Results reveal pronounced lateral particle motion in the ethanol layer, attributed to a higher Galileo number (

$Ga = 976$

, ratio of buoyancy–gravity to viscous effects), compared with the less active behaviour in the oil layer (

$Ga = 16$

). The ensemble vertical velocity of particles exhibited a minimum just past the density interface, becoming more pronounced with increasing

$H_1$

, and suggesting that enhanced entrainment from ethanol to oil resulted in an additional buoyancy force. This produced distinct patterns of particle acceleration near the density interface, which were marked by significant deceleration, indicating substantial resistance to particle motion. An increased drag coefficient occurred for

$H_1/d = 40$

compared with a single particle settling in oil; drag reduced as the particle-release frequency (

$\,f_p$

) increased, likely due to enhanced particle interactions at closer proximity. Particle pair dispersions, lateral (

$R^2_L$

) and vertical (

$R^2_z$

), were modulated by

$H_1$

, initial separation

$r_0$

and

$f_p$

. The

$R^2_L$

dispersion displayed ballistic scaling initially, Taylor scaling for

$r_0 < H_1$

and Richardson scaling for

$r_0 > H_1$

. In contrast,

$R^2_z$

followed a

$R^2_z \sim t^{5.5}$

scaling under

$r_0 < H_1$

. Both

$R^2_L$

and

$R^2_z$

plateaued at a distance from the interface, depending on

$H_1$

and

$f_p$

.
Is Attention always needed? A case study on language identification from speech
Authors: Mandal Atanu , Pal Santanu , Dutta Indranil , Bhattacharya Mahidas , Naskar Sudip Kumar
Published: May 2024

Language identification (LID) is a crucial preliminary process in the field of Automatic Speech Recognition (ASR) that involves the identification of a spoken language from audio samples. Contemporary systems that can process speech in multiple languages require users to expressly designate one or more languages prior to utilisation. The LID task assumes a significant role in scenarios where ASR systems are unable to comprehend the spoken language in multilingual settings, leading to unsuccessful speech recognition outcomes. The present study introduces convolutional recurrent neural network (CRNN)-based LID, designed to operate on the mel-frequency cepstral coefficient (MFCC) characteristics of audio samples. Furthermore, we replicate certain state-of-the-art methodologies, specifically the convolutional neural network (CNN) and Attention-based convolutional recurrent neural network (CRNN with Attention), and conduct a comparative analysis with our CRNN-based approach. We conducted comprehensive evaluations on thirteen distinct Indian languages, and our model resulted in over 98 per cent classification accuracy. The LID model exhibits high-performance levels ranging from 97 per cent to 100 per cent for languages that are linguistically similar. The proposed LID model exhibits a high degree of extensibility to additional languages and demonstrates a strong resistance to noise, achieving 91.2 per cent accuracy in a noisy setting when applied to a European Language (EU) dataset.
Distribution and host ranges of Ceratitis rosa and Ceratitis quilicii (Diptera: Tephritidae) in South Africa
Authors: Tsatsu Seth Kwaku , Sutton Guy F. , Serfontein Leani , Addison Pia , De Meyer Marc , Virgilio Massimiliano , Manrakhan Aruna
Published: May 2024

Two fruit fly (Diptera: Tephritidae) species of economic importance: Ceratitis rosa Karsch and Ceratitis quilicii De Meyer, Mwatawala & Virgilio are present in South Africa. The two species were considered as one species prior to 2016, but were subsequently separated. In this study, the distribution and abundance of the two species were quantified in seven provinces in South Africa through trapping with Enriched Ginger Oil as an attractant. Trapping was conducted over three seasons across two years (2020 and 2021): late summer, autumn-winter, and spring-early summer. Host ranges of the two species were investigated by fruit sampling in and outside of trapping sites. Ceratitis quilicii was more widely distributed than C. rosa with the latter being recorded in only three north-eastern provinces. There were geographical limits for both species with no records of them in Northern Cape Province. Catches of C. quilicii were higher in summer with average temperatures varying from 15 to 27°C while for C. rosa, catches remained low and consistent between seasons. Ceratitis quilicii catches decreased at lower rates than those of C. rosa at temperatures below 15°C. The two species were reared from 13 plant species from nine families. Four of these hosts were infested by both C. quilicii and C. rosa in the same province where they occurred. Preferred hosts of the two species belonged to the Myrtaceae family. The characterisation of the distribution, abundance and host ranges of these pests will provide a baseline for pest status determination and implementation of management actions.
A linear linear lambda-calculus
Authors: Díaz-Caro Alejandro , Dowek Gilles
Published: May 2024

We present a linearity theorem for a proof language of intuitionistic multiplicative additive linear logic, incorporating addition and scalar multiplication. The proofs in this language are linear in the algebraic sense. This work is part of a broader research program aiming to define a logic with a proof language that forms a quantum programming language.
METHODOLOGY AND CHALLENGES OF SURROGATE MODELLING METHODS FOR MULTI-FIDELITY EXPENSIVE BLACK-BOX PROBLEMS
Authors: ANDRÉS-THIÓ NICOLAU , MUÑOZ MARIO ANDRÉS , SMITH-MILES KATE
Published: May 2024

Many industrial design problems are characterized by a lack of an analytical expression defining the relationship between design variables and chosen quality metrics. Evaluating the quality of new designs is therefore restricted to running a predetermined process such as physical testing of prototypes. When these processes carry a high cost, choosing how to gather further data can be very challenging, whether the end goal is to accurately predict the quality of future designs or to find an optimal design. In the multi-fidelity setting, one or more approximations of a design’s performance are available at varying costs and accuracies. Surrogate modelling methods have long been applied to problems of this type, combining data from multiple sources into a model which guides further sampling. Many challenges still exist; however, the foremost among them is choosing when and how to rely on available low-fidelity sources. This tutorial-style paper presents an introduction to the field of surrogate modelling for multi-fidelity expensive black-box problems, including classical approaches and open questions in the field. An illustrative example using Australian elevation data is provided to show the potential downfalls in blindly trusting or ignoring low-fidelity sources, a question that has recently gained much interest in the community.
Task-shifting and the recruitment and retention of eye care workers in under-served areas: a qualitative study of optometrists’ motivation in Ghana and Scotland
Authors: Somerville Joel G. , Strang Niall C. , Jonuscheit Sven
Published: May 2024

Aim:

To assist policy-makers in improving access to eye care in under-served areas by analysing the relationship between motivational factors affecting the uptake of task-shifting in eye care and the recruitment and retention of optometrists in remote and rural areas.

Background:

The World Health Organization recommends two key strategies in tackling preventable blindness in under-served areas: improving human resources for health and task-shifting. The relationship between task-shifting and recruitment and retention of eye care workers in under-served areas is unknown. Ghana and Scotland are two countries from different levels of economic development that have notably expanded the roles of optometrists and struggle with rural recruitment and retention.

Methods:

Motivation was explored through semi-structured interviews with 19 optometrists in Ghana and Scotland with experience in remote and rural practice. Framework analysis was used to analyse interviews, explore the relationship between task-shifting and recruitment and retention and create recommendations for policy.

Findings:

The main motivational considerations included altruism, quality of life, learning and career opportunities, fulfilling potential, remuneration, stress of decision-making and collaboration. Motivational and demotivational factors for task-shifting and recruitment/retention shared many similar aspects.

Discussion:

Recruitment and retention in remote and rural areas require staff be incentivised to take up those positions, motivated to remain and given the adequate resources for personal and professional fulfilment. Task-shifting also requires incentivisation, motivation to continue and the resources to be productive. Many motivational factors influencing recruitment/retention and task-shifting are similar suggesting these two strategies can be compatible and complementary in improving access to eye care, although some factors are culture and context specific. Understanding optometrists’ motivation can help policy-makers improve rural recruitment and retention and plan services.
Pandemic preparedness and response: a new mechanism for expanding access to essential countermeasures
Authors: Hassoun Nicole , Basu Kaushik , Gostin Lawrence
Published: May 2024

As the world comes together through the WHO design and consultation process on a new medical counter-measures platform, we propose an enhanced APT-A (Access to Pandemic Tools Accelerator) that builds on the previous architecture but includes two new pillars – one for economic assistance and another to combat structural inequalities for future pandemic preparedness and response. As part of the APT-A, and in light of the Independent Panel on Pandemic Preparation & Response's call for an enhanced end-to-end platform for access to essential health technologies, we propose a new mechanism that we call the Pandemic Open Technology Access Accelerator (POTAX) that can be implemented through the medical countermeasures platform and the pandemic accord currently under negotiation through the World Health Assembly and supported by the High-Level Meeting review on Pandemic Prevention, Preparedness, and Response at the United Nations. This mechanism will provide (1) conditional financing for new vaccines and other essential health technologies requiring companies to vest licenses in POTAX and pool intellectual property and other data necessary to allow equitable access to the resulting technologies. It will also (2) support collective procurement as well as measures to ensure equitable distribution and uptake of these technologies.
Minderjährige in klinischen Prüfungen: Ethische Abwägungen ihres Einbezugs am Beispiel der indizierten Prävention psychotischer Erkrankungen
Authors: Schultze-Lutter Frauke , Banaschewski Tobias , Barth Gottfried M. , Bechdolf Andreas , Bender Stephan , Flechtner Hans-Henning , Hackler Sandra , Heuer Fabiola , Hohmann Sarah , Holzner Laura , Huss Michael , Koutsouleris Nikolaos , Lipp Michael , Mandl Selina , Meisenzahl Eva , Munz Manuel , Osman Naweed , Peschl Jens , Reissner Volker , Renner Tobias , Riedel Anett , Romanos Marcel , Romer Georg , Schomerus Georg , Thiemann Ulf , Uhlhaas Peter J. , Woopen Christiane , Correll Christoph U. , CARE-Konsortium das
Published: May 2024

Zusammenfassung: Minderjährige sind als vulnerable Gruppe in Studien besonders zu schützen. Daher sind Forscher_innen bei der Studieninitiierung und Ethikkommissionen bei der Studienbewilligung oft zurückhaltend, so dass Minderjährigen von der Studienteilnahme häufig ausgeschlossen sind. Dieser Ausschluss kann dazu führen, dass Forscher_innen und Kliniker_innen nur unvollständige Daten erhalten oder auf erwachsenenbasierte Erkenntnisse zur Behandlung von Minderjährigen zurückgreifen müssen. Am Beispiel der als sonstige klinische Prüfung nach der Verordnung über Medizinprodukte durchgeführten Studie „Computer-assistierte Risiko-Evaluation in der Früherkennung psychotischer Erkrankungen“ (CARE) soll ein Argumentationsstrang zum Einschluss von Minderjährigen aufgezeigt werden, der die ethischen Prinzipien des Nicht-Schadens (insbesondere in Bezug auf etwaige Stigmatisierungen), der Fürsorge, der Autonomie und der Fairness abwägt, die Notwendigkeit des Einschlusses von Minderjährigen anhand der entwicklungsspezifischen Unterschiede in Diagnostik und Frühintervention aufzeigt sowie die spezifischen Schutzmaßnahmen darstellt. Die dargestellte Argumentation lässt sich beispielhaft auch auf andere Krankheitsbilder mit Beginn im Kindes- und Jugendalter übertragen und soll damit helfen, Minderjährige nicht von einer geeigneten evidenzbasierten Versorgung durch eine mangelhafte Studienlage auszuschließen.
River Ecomorphodynamic Models Exhibit Features of Nonlinear Dynamics and Chaos
Authors: Cunico I. , Bertoldi W. , Caponi F. , Dijkstra H. A. , Siviglia A.
Published: May 2024

Modeling the nonlinear interactions between flow, sediment, and vegetation is essential for improving our understanding and prediction of river system dynamics. Using simple numerical models, we simulate the key flow‐sediment‐vegetation interaction where the disturbance is intrinsically generated by the presence of vegetation. In this case, biomass growth modifies the flow field, induces bed scour, and thus potentially causes vegetation uprooting when erosion exceeds root depth. Our results show that this nonlinear feedback produces deterministic chaos under a wide range of conditions, with complex aperiodic dynamics generated by a period‐doubling route to chaos. Moreover, our results suggest relatively small values of Lyapunov time, spanning 2–4 growth‐flood cycles, which significantly restrict the predictability of riverbed evolution. Although further spatial and temporal processes may add complexity to the system, these results call for the use of ensemble methods and associated uncertainty estimates in ecomorphodynamic models.
Co‐Occurrence of Low and Very Low Frequency Earthquakes Explained From Dynamic Modeling
Authors: Wei Xueting , Liu Yuxiang , Xu Jiankuan , Chen Xiaofei
Published: May 2024

Very low‐frequency earthquakes (VLFs) are characterized by longer source duration and smaller stress drop than regular earthquakes of similar magnitude. Recent studies have shown their frequent correlation with low‐frequency earthquakes (LFEs) on shared faults. The underlying source processes governing the occurrence of VLFs and their interaction with LFEs remain elusive. Here, we employ a slip‐weakening model for slow earthquakes. By comparing the source parameters of simulations and observations, it is suggested that VLFs are slow self‐arresting earthquakes that self‐terminate within the nucleation patch. Additionally, we adopt a composite model to reproduce the records of the simultaneous occurrences of a VLF and an LFE in the Nankai area. Our results present the possibility that VLFs, LFEs, and regular earthquakes can be distinguished using a unified dynamic framework.
Field‐Aligned Currents Associated With Pulsating Auroral Patches: Observation With Magneto‐Impedance Magnetometer (MIM) Onboard Loss Through Auroral Microburst Pulsations (LAMP) Sounding Rocket
Authors: Nosé Masahito , Hosokawa Keisuke , Nomura Reiko , Teramoto Mariko , Asamura Kazushi , Miyoshi Yoshizumi , Mitani Takefumi , Sakanoi Takeshi , Namekawa Taku , Kawano Takeshi , Iwanaga Yoshihiro , Tatematsu Shunichi , Hirahara Masafumi , Halford Alexa , Shumko Mykhaylo , Lessard Marc R. , Lynch Kristina , Paschalidis Nicholaos , Jaynes Allison N. , McHarg Matthew G.
Published: May 2024

We made observations of magnetic field variations in association with pulsating auroras with the magneto‐impedance sensor magnetometer (MIM) carried by the Loss through Auroral Microburst Pulsations (LAMP) sounding rocket that was launched at 11:27:30 UT on 5 March 2022 from Poker Flat Research Range, Alaska. At an altitude of 200–250 km, MIM detected clear enhancements of the magnetic field by 15–25 nT in both the northward and westward components. From simultaneous observations with the ground all‐sky camera, we found that the footprint of LAMP at the 100 km altitude was located near the center of a pulsating auroral patch. The auroral patch had a dimension of ∼90 km in latitude and ∼25 km in longitude, and its major axis was inclined toward northwest. These observations were compared with results of a simple model calculation, in which local electron precipitation into the thin‐layer ionosphere causes an elliptical auroral patch. The conductivity within the patch is enhanced in the background electric field and as a result, the magnetic field variations are induced around the auroral patch. The model calculation results can explain the MIM observations if the electric field points toward southeast and one of the model parameters is adjusted. We conclude that the pulsating auroral patch in this event was associated with a one‐pair field‐aligned current that consists of downward (upward) currents at the poleward (equatorward) edge of the patch. This current structure is maintained even if the auroral patch is latitudinally elongated.
Converging Findings of Climate Models and Satellite Observations on the Positive Impact of European Forests on Cloud Cover
Authors: Caporaso Luca , Duveiller Gregory , Giuliani Graziano , Giorgi Filippo , Stengel Martin , Massaro Emanuele , Piccardo Matteo , Cescatti Alessandro
Published: May 2024

Although afforestation is a potential strategy to mitigate climate change by sequestering carbon, its potential biophysical effects on climate, such as regulating surface albedo, evapotranspiration, and energy balance, have not been fully incorporated into climate change mitigation strategies. This is partly due to the challenges associated with modeling the complex bidirectional interactions between vegetation and climate. In this study, we assess the impact of afforestation on low cloud cover using a regional climate model (RCM) and Earth observation data, applying a space‐for‐time approach to overcome limitations that may arise from comparing satellite and RCM results, such as different background climate conditions or different extents of land cover change. Our results show a consistent increase in low cloud cover in Europe due to afforestation in both datasets (3.71% and 3.56% on average, respectively), but the magnitude and direction of this effect depend on various factors, including location, seasonality, and forest type. These results suggest that afforestation can have important feedbacks on the climate system, and that its biophysical effects must be considered in climate change mitigation strategies. Furthermore, we emphasize the role of the modeling community in developing accurate and reliable approaches to assess the biophysical effects of land cover change on climate.
The Role of Deposition of Cosmogenic 10Be for the Detectability of Solar Proton Events
Authors: Schaar K. , Spiegl T. , Langematz U. , Sato T. , Mekhaldi F. , Kunze M. , Miyake F. , Yoden S.
Published: May 2024

The manifestation of extreme solar proton events (SPEs) in Beryllium‐10 (10Be) ice core data contains valuable information about the strength and incidence of SPEs or local characteristics of the atmosphere. To extract this information, the signals of enhanced production of cosmogenic 10Be due to the SPEs have to be detected, hence distinguished from the variability of the background production by galactic cosmic rays (GCRs). Here, we study the transport and deposition of 10Be from GCRs, using the ECHAM/MESSy Atmospheric Chemistry climate model, and discuss the detectability of extreme SPEs (similar to the CE 774/775 SPE) in 10Be ice core data depending on the ice core location, seasonal appearance of the SPE, atmospheric aerosol size distribution and phase of the 11‐year solar cycle. We find that sedimentation can be a major deposition mechanism of GCR generated 10Be, especially at high latitudes, depending on the aerosols to which 10Be attaches after production. The comparison of our results to four ice core records of 10Be from Greenland and Antarctica shows good agreement for both 10Be from GCRs and solar energetic particles (SEP). From our results we deduce that the location of detection and the season of occurrence of the SPE have a considerable effect on its detectability, as well as the aerosol size distribution the produced cosmogenic nuclides meet in the atmosphere. Furthermore, we find that SPEs occurring in the phase of highest activity during the 11‐year solar cycle are more detectable than SPEs that arise in the phase of lowest activity.
Why Do Oceanic Nonlinearities Contribute Only Weakly to Extreme El Niño Events?
Authors: Liu Fangyu , Vialard Jérôme , Fedorov Alexey V. , Éthé Christian , Person Renaud , Zhang Wenjun , Lengaigne Matthieu
Published: May 2024

Extreme El Niño events have outsized global impacts and control the El Niño Southern Oscillation (ENSO) warm/cold phases asymmetries. Yet, a consensus regarding the relative contributions of atmospheric and oceanic nonlinearities to their genesis remains elusive. Here, we isolate the contribution of oceanic nonlinearities by conducting paired experiments forced with opposite wind stress anomalies in an oceanic general circulation model, which realistically simulates extreme El Niño events and oceanic nonlinearities thought to contribute to ENSO skewness (Tropical Instability Waves (TIWs), Nonlinear Dynamical Heating (NDH)). Our findings indicate a weak contribution of oceanic nonlinearities to extreme El Niño events in the eastern Pacific, owing to compensatory effects between lateral (NDH and TIWs) and vertical processes. These results hold across different vertical mixing schemes and modifications of the upper‐ocean heat budget mixed layer criterion. Our study reinforces previous research underscoring the pivotal role of atmospheric nonlinearities in shaping extreme El Niño events.
Multichannel microneedle dry electrode patches for minimally invasive transdermal recording of electrophysiological signals
Authors: Liu Zhengjie , Xu Xingyuan , Huang Shuang , Huang Xinshuo , Liu Zhibo , Yao Chuanjie , He Mengyi , Chen Jiayi , Chen Hui-jiuan , Liu Jing , Xie Xi
Published: May 2024

The collection of multiple-channel electrophysiological signals enables a comprehensive understanding of the spatial distribution and temporal features of electrophysiological activities. This approach can help to distinguish the traits and patterns of different ailments to enhance diagnostic accuracy. Microneedle array electrodes, which can penetrate skin without pain, can lessen the impedance between the electrodes and skin; however, current microneedle methods are limited to single channels and cannot achieve multichannel collection in small areas. Here, a multichannel (32 channels) microneedle dry electrode patch device was developed via a dimensionality reduction fabrication and integration approach and supported by a self-developed circuit system to record weak electrophysiological signals, including electroencephalography (EEG), electrocardiogram (ECG), and electromyography (EMG) signals. The microneedles reduced the electrode–skin contact impedance by penetrating the nonconducting stratum corneum in a painless way. The multichannel microneedle array (MMA) enabled painless transdermal recording of multichannel electrophysiological signals from the subcutaneous space, with high temporal and spatial resolution, reaching the level of a single microneedle in terms of signal precision. The MMA demonstrated the detection of the spatial distribution of ECG, EMG and EEG signals in live rabbit models, and the microneedle electrode (MNE) achieved better signal quality in the transcutaneous detection of EEG signals than did the conventional flat dry electrode array. This work offers a promising opportunity to develop advanced tools for neural interface technology and electrophysiological recording.
Targeting the autophagy-NAD axis protects against cell death in Niemann-Pick type C1 disease models
Authors: Kataura Tetsushi , Sedlackova Lucia , Sun Congxin , Kocak Gamze , Wilson Niall , Banks Peter , Hayat Faisal , Trushin Sergey , Trushina Eugenia , Maddocks Oliver D. K. , Oblong John E. , Miwa Satomi , Imoto Masaya , Saiki Shinji , Erskine Daniel , Migaud Marie E. , Sarkar Sovan , Korolchuk Viktor I.
Published: May 2024

Impairment of autophagy leads to an accumulation of misfolded proteins and damaged organelles and has been implicated in plethora of human diseases. Loss of autophagy in actively respiring cells has also been shown to trigger metabolic collapse mediated by the depletion of nicotinamide adenine dinucleotide (NAD) pools, resulting in cell death. Here we found that the deficit in the autophagy-NAD axis underpins the loss of viability in cell models of a neurodegenerative lysosomal storage disorder, Niemann-Pick type C1 (NPC1) disease. Defective autophagic flux in NPC1 cells resulted in mitochondrial dysfunction due to impairment of mitophagy, leading to the depletion of both the reduced and oxidised forms of NAD as identified via metabolic profiling. Consequently, exhaustion of the NAD pools triggered mitochondrial depolarisation and apoptotic cell death. Our chemical screening identified two FDA-approved drugs, celecoxib and memantine, as autophagy activators which effectively restored autophagic flux, NAD levels, and cell viability of NPC1 cells. Of biomedical relevance, either pharmacological rescue of the autophagy deficiency or NAD precursor supplementation restored NAD levels and improved the viability of NPC1 patient fibroblasts and induced pluripotent stem cell (iPSC)-derived cortical neurons. Together, our findings identify the autophagy-NAD axis as a mechanism of cell death and a target for therapeutic interventions in NPC1 disease, with a potential relevance to other neurodegenerative disorders.