bluuebunny/crossref_metadata_2025 huggingface dataset:
Intensive 2-days training on perfused human placenta for microvascular anastomoses
Authors: Colombo Elisa , Wolf Fabian , Helg Fiona , Höbner Lara , Watson Jennifer A. , Sebök Martina , Haslinger Christian , van Doormaal Tristan , Regli Luca , Esposito Giuseppe
Published: November 2024

Background and Purpose

We report on an intensive two-day training program on microanastomoses performed on perfused human placenta models. A specific scoring system was elaborated to evaluate the participants’ microsurgical skills and report the participants’ results.

Materials and Methods

Trainees who attended the Zurich Microsurgery Courses in 2023 were included in the study. Before performing the microanastomoses, each participant received a visual didactic training. Training was made on perfused human placenta models. To perform the microvascular anastomoses, vessels of different diameters were chosen, and 9–0 and 10–0 microsutures were used. The course was structured in two days. On day one, participants practiced microvascular dissection, microsuturing and end-to-end anastomoses, while the second day was dedicated to end-to-side and to repeat the most useful microanastomosis depending on the specialty. A score system for the evaluation of a successful microanastomosis was developed and applied to assess the participants’ anastomoses. User satisfaction was measured by means of a survey-based questionnaire.

Results

Fifty-two participants from different institutions, specializations and levels of experience were included. A significant improvement in the overall microsurgical skills of the included cohort was documented (p < 0.005). The initial average score per anastomosis of 3.56 points (SD 0.71) increased to an average of 3.8 points (SD 0.87) at the end of the course. The steepest learning curve was observed in the placement of knots (Δ 0.48 points, p = 0.003) and microvascular dissection (Δ 0.44 points, p = 0.002). Most participants rated the fidelity and importance of the placental microsuturing course as extremely high.

Conclusion

The two-day training program is efficient to teach microvascular dissection and microanastomosis techniques. A significant improvement of participants’ microsurgical skills was reported. The human placenta model proved to be a high-fidelity simulator with great user satisfaction.
An orthogonal approach for analysis of underivatized steroid hormones using ultrahigh performance supercritical fluid chromatography-mass spectrometry (UHPSFC-MS)
Authors: Devo Perry , Cretu Victoria , Radhakrishnan Harsha , Hamilton-Pink Darren , Boussios Stergios , Ovsepian Saak V.
Published: November 2024

The crucial role of steroid hormones in health and diseases merits their high-throughput, accurate and affordable measurements in biological specimens. Despite advances in analytical methods, sensing and quantifying steroid hormones remains challenging. Immunoassays offer excellent sensitivity but are inherently labour-intensive, costly, and prone to false positives. Mass spectrometry (MS) has been increasingly utilised, with the main hurdle being the isobaric tendencies of similar analytes, which complicates their separation and accurate quantification. This study compares ultrahigh-performance supercritical fluid chromatography separation (UHPSFC) and ultra-high-performance liquid chromatography (UHPLC) for MS detection. It optimises the column chemistry, temperature, and pressure to provide an operational protocol for the resolution and quantification of analytes. It presents the systematic characterisation of UHPSFC-MS performance by investigating spiked blood samples using Solid-Phase Extraction (SPE) and describes the matrix effects associated with MS measurements. Although both separation methods showed adequate resolution, specificity, and retention time, UHPSFC-MS was superior for five out of seven columns tested. With added high-throughput capacities, UHPSFC-MS, thus, offers an optimal solution for the analysis of steroid hormones for research, medical chemistry, and clinical diagnostics.
The microbiota-gut-brain axis: a potential target in the small-molecule compounds and gene therapeutic strategies for Parkinson’s disease
Authors: Jiao Fengjuan , Zhou Lincong , Wu Zaixin
Published: November 2024

Backgrounds

Parkinson’s disease (PD) is a common neurodegenerative disorder characterized by motor symptoms and non-motor symptoms. It has been found that intestinal issues usually precede motor symptoms. Microorganisms in the gastrointestinal tract can affect central nervous system through the microbiota-gut-brain axis. Accumulating evidence has shown that disturbances in the microbiota-gut-brain axis are linked with PD. Thus, this pathway appears to be a promising therapeutic target for treatment of PD.

Objectives

In this review, we mainly described gut dysbiosis in PD and their underlying mechanisms for mediating neuroinflammation and peripheral immune response in PD pathology and futher discussed the potential small-molecule compounds and genic therapeutic strategies targeting the microbiota-gut-brain axis and their applications in PD.

Conclusions

Studies have found that some small molecule compounds and alterations of inflammation-related genes can improve the motor and non-motor symptoms of PD by improving the microbiota-gut-brain axis, which may provide potentially beneficial drugs and molecular targets for the therapies of PD.
Deep Reinforcement Learning for the Management of the Wall Regeneration Cycle in Wall-Bounded Turbulent Flows
Authors: Cavallazzi Giorgio Maria , Guastoni Luca , Vinuesa Ricardo , Pinelli Alfredo
Published: November 2024

The wall cycle in wall-bounded turbulent flows is a complex turbulence regeneration mechanism that remains not fully understood. This study explores the potential of deep reinforcement learning (DRL) for managing the wall regeneration cycle to achieve desired flow dynamics. To create a robust framework for DRL-based flow control, we have integrated the StableBaselines3 DRL libraries with the open-source direct numerical simulation (DNS) solver CaNS. The DRL agent interacts with the DNS environment, learning policies that modify wall boundary conditions to optimise objectives such as the reduction of the skin-friction coefficient or the enhancement of certain coherent structures’ features. The implementation makes use of the message-passing-interface (MPI) wrappers for efficient communication between the Python-based DRL agent and the DNS solver, ensuring scalability on high-performance computing architectures. Initial experiments demonstrate the capability of DRL to achieve drag reduction rates comparable with those achieved via traditional methods, although limited to short time intervals. We also propose a strategy to enhance the coherence of velocity streaks, assuming that maintaining straight streaks can inhibit instability and further reduce skin-friction. Our results highlight the promise of DRL in flow-control applications and underscore the need for more advanced control laws and objective functions. Future work will focus on optimising actuation intervals and exploring new computational architectures to extend the applicability and the efficiency of DRL in turbulent flow management.
A political economy perspective of the constitution of ancient Sparta: conflict resolution, credibility, and stability
Authors: Tridimas George
Published: November 2024

Uniquely in Ancient Greece the constitution of Sparta provided for two kings from different dynasties reigning simultaneously, an aristocratic upper house, an annually elected board of overseers, an assembly, and a society of warriors to rule over an enslaved neighbouring population. It contributed to Sparta’s elevation to a great power and lasted almost unaltered for five hundred years until the middle of the third century BCE. The paper argues that the intricate constitutional order resolved internal conflicts about income distribution that had plagued Sparta in her early days. The dual kingship was a power sharing arrangement to avoid intra-elite fighting. Constraints on royal power, military organization and conquest of foreign lands secured redistribution to the Spartan poor solving inter-group conflict between the rich and the poor. The checks and balances provided by the constitution served to credibly commit the elite to the settlements. However, the rigidity of the constitution ossified Sparta’s society who could not respond to changing circumstances.
Procedural fairness in algorithmic decision-making: the role of public engagement
Authors: Decker Marie Christin , Wegner Laila , Leicht-Scholten Carmen
Published: November 2024

Despite the widespread use of automated decision-making (ADM) systems, they are often developed without involving the public or those directly affected, leading to concerns about systematic biases that may perpetuate structural injustices. Existing formal fairness approaches primarily focus on statistical outcomes across demographic groups or individual fairness, yet these methods reveal ambiguities and limitations in addressing fairness comprehensively. This paper argues for a holistic approach to algorithmic fairness that integrates procedural fairness, considering both decision-making processes and their outcomes. Procedural fairness emphasizes the importance of fair decision-making procedures, which aligns with theories of relational justice that stress the quality of social relations and power dynamics. We highlight the need for substantive procedural fairness to ensure better outcomes and address forward-looking responsibilities. Additionally, we propose leveraging Public Engagement, a core dimension within the well-established Responsible Research and Innovation framework, to enhance procedural fairness in ADM systems. Our contribution underscores the value of Public Engagement in fostering fairer ADM processes, thereby expanding the current focus beyond technical outcome-based approaches to encompass broader procedural considerations.
Genetic diversity of Dalbergia melanoxylon Guill. & Perr. populations in the Ferlo zone (Senegal) using nuclear and chloroplast microsatellite markers
Authors: Ndiaye Lémou , Diallo Adja Madjiguene , Vu Thi Ha Giang , Mueller Markus , Ngom Daouda , Mbaye Tamsir , Gailing Oliver
Published: November 2024

Dalbergia melanoxylon Guill. & Perr. is a highly valued species in the Ferlo region, and its wood is used for various purposes by local populations, including firewood, service wood, and timber. This multifunctionality has weakened its populations, and it has been identified as threatened in previous research. The aim of this study was to investigate the genetic variability of three populations (LC, VC, and YC) along a north–south rainfall gradient, to support the species’ sustainable management and conservation. Eighteen microsatellite markers were used, including eight nuclear (nSSR) and 10 chloroplast (cpSSR) markers, to test their transferability to D. melanoxylon and study the genetic variability. The results showed that all nSSRs and cpSSRs were transferable, however, only five nSSRs and one cpSSR were polymorphic and used in the downstream analysis. Based on the nSSRs, comparatively high, but non-significantly different, genetic variation was found in all populations (LC: He = 0.650, VC: He = 0.674, YC: He = 0.706), however, indications of inbreeding were detected. For the single polymorphic cpSSR, three haplotypes were identified. Haplotype diversity (Hd) varied in LC (Hd = 0.536), VC (Hd = 0.577), and YC (Hd = 0.674). Low to moderate genetic differentiation was observed between populations (Fst nSSR = 0.019 and Fst cpSSR = 0.133) suggesting recent fragmentation of populations that has not yet impacted genetic variation but could become more pronounced in future generations. This finding underscores the need for further research on effective management and conservation strategies for D. melanoxylon populations in the Ferlo region.
Revisiting a Faculty Career Management Life Cycle Model: Anticipating and Navigating Career Transitions in Academic Medicine
Authors: Buer Troy S. , Kutzler Michele A. , Salcedo Abbie , Overholser Barbara , Pollart Susan M. , Spector Nancy D.
Published: November 2024

Career management models are valuable tools for faculty pursuing a career in academic medicine. These models help faculty transition through various stages of their careers, including commonly pursued academic advancements from assistant professor to full professor, as well as less common transitions like moving from full-time to part-time status, taking sabbaticals, going on medical leave, or assuming executive leadership roles. The success of faculty members across these stages is influenced by both environmental factors and individual-level characteristics. Recognizing career stages and transitions, as well as the impact of personal and environmental factors on career growth, is crucial. The proposed Faculty Career Self-Management Model (FCSM) provides a visual and descriptive framework to guide individual faculty and the professionals who support them in understanding, preparing for, and navigating career stages and professional transitions to build and sustain meaningful careers in academic medicine. The FCSM serves as a framework to explore, develop, and share best practices in supporting faculty vitality across the career lifespan.
Production and purification of molecular 225Ac at CERN-ISOLDE
Authors: Au M. , Nies L. , Stegemann S. , Athanasakis-Kaklamanakis M. , Cocolios T. E. , Fischer P. , Giesel P. F. , Johnson J. D. , Köster U. , Lange D. , Mougeot M. , Reilly J. , Schlaich M. , Schweiger Ch. , Schweikhard L. , Wienholtz F. , Wojtaczka W. , Düllmann Ch. E. , Rothe S.
Published: November 2024

The radioactive nuclide 225Ac is one of the few promising candidates for cancer treatment by targeted-$$\alpha$$
α
-therapy, but worldwide production of 225Ac faces significant limitations. In this work, the Isotope Separation On-Line method was used to produce actinium by irradiating targets made of uranium carbide and thorium carbide with 1.4-GeV protons. Actinium fluoride molecules were formed, ionized through electron impact, then extracted and mass-separated as a beam of molecular ions. The composition of the mass-selected ion beam was verified using time-of-flight mass spectrometry, $$\alpha$$
α
- and $$\gamma$$
γ
-ray decay spectrometry. Extracted quantities of $$^{225}\textrm{Ac}^{19}\textrm{F}_2^{+}$$

225

Ac
19

F
2
+

particles per $$\upmu$$
μ
C of incident protons were $$3.9(3)\times 10^7$$

3.9

(
3
)

×

10
7

from a uranium carbide target and $$4.3(4)\times 10^7$$

4.3

(
4
)

×

10
7

for a thorium carbide target. Using a magnetic mass separator, the long-lived contamination 227 Ac is suppressed to $$<5.47\times 10^{-7}$$

<
5.47
×

10

-
7

(95% confidence interval) with respect to 225Ac by activity. Measured rates scale to collections of 108 kBq$$\upmu$$
μ
A$$^{-1}$$

-
1

h$$^{-1}$$

-
1

of directly produced $$^{225}\textrm{Ac}^{19}\textrm{F}_2^{+}$$

225

Ac
19

F
2
+

.
Modeling the radon build-up in a closed environment using developed OpenFOAM solver
Authors: Rana Dibyendu , Jha Vivekanand , Patnaik RLokeswara , Singh Manish Kumar , Jha Sanjay Kumar
Published: November 2024

Modeling radon (222Rn) development in confined environments aids in predicting radon levels in dwellings and underground spaces, where radium 226Ra in building materials and soil emits radon gas via radioactive decay. Radon accumulates in poorly ventilated places, creating an inhalation hazard. In OpenFOAM, a C+ +-based computational tool, an existing heat conduction solver was adapted to simulate radon accumulation, considering radon's radioactive characteristics and material non-uniformity through which radon will permeate. The solver was validated against theoretical values in a one-dimensional system and then applied to study radon dispersion in containment, with potential for broader applications.
Physical reservoir computing: a tutorial
Authors: Stepney Susan
Published: November 2024

This tutorial covers physical reservoir computing from a computer science perspective. It first defines what it means for a physical system to compute, rather than merely evolve under the laws of physics. It describes the underlying computational model, the Echo State Network (ESN), and also some variants designed to make physical implementation easier. It explains why the ESN model is particularly suitable for direct physical implementation. It then discusses the issues around choosing a suitable material substrate, and interfacing the inputs and outputs. It describes how to characterise a physical reservoir in terms of benchmark tasks, and task-independent measures. It covers optimising configuration parameters, exploring the space of potential configurations, and simulating the physical reservoir. It ends with a look at the future of physical reservoir computing as devices get more powerful, and are integrated into larger systems.
Exploiting neural networks bit-level redundancy to mitigate the impact of faults at inference
Authors: Catalán Izan , Flich José , Hernández Carles
Published: November 2024

Neural networks are widely used in critical environments such as healthcare, autonomous vehicles, or video surveillance. To ensure the safety of the systems that rely on their functionality, it is essential to validate their correct behaviour in the presence of faults. This paper studies the behaviour of state-of-the-art neural network models with fault injection in their weights. For this purpose, we analyse the sensitivity of these models and identify the impact of bit flips on their accuracy. To mitigate the effects of faults, we introduce two mechanisms that leverage bit-level redundancy for protection. The first mechanism, Fixed Protection, safeguards consecutive sets of bits, while the second, Variable Protection, targets non-consecutive bits. Our findings demonstrate that, on average, random bit flip faults cause the accuracy of the original models to drop by 1.3% to over 3%. However, with our protection mechanisms in place, accuracy reductions are significantly minimised, ranging from only 0.0001% to 0.4%.
Using multiwinner voting to search for movies
Authors: Gawron Grzegorz , Faliszewski Piotr
Published: November 2024

We show a prototype of a system that uses multiwinner voting to suggest resources (such as movies) related to a given query set (such as a movie that one enjoys). Depending on the voting rule used, the system can either provide resources very closely related to the query set or a broader spectrum of options. We show how this ability can be interpreted as a way of controlling the diversity of the results. We test our system both on synthetic data and on the real-life collection of movie ratings from the MovieLens dataset. We also present a visual comparison of the search results corresponding to selected diversity levels.
Timing and experience in global markets: unraveling the impact of servitization on new manufacturing venture survival
Authors: Wang Weiyu , Guedes Maria João
Published: November 2024

The emergence of global competition and advances in technology have prompted manufacturing firms to reshape their competitive strategies in global markets. Servitization is an innovative strategy, which integrates services into traditional products to offer both domestic and international customers greater value added. In the context of international entrepreneurship and drawing on the resource-based view and internationalization perspectives, this study investigates the relationship between servitization and the survival of new manufacturing ventures that are engaging in global markets. In addition, it further explores whether the pre-internationalization preparation and post-internationalization experience can moderate the servitization-survival relationship from the perspectives of costs, resources, and capabilities developed in different stages. Our findings support the view that, in the context of international markets, new manufacturing ventures are more vulnerable to risk and the additional costs of servitization coupled with the uncertainty of international markets. Later entry into foreign markets and greater international experience enable manufacturing ventures to resist the hazards associated with servitization and the process of internationalization. In doing so, we contribute to an understanding of the service paradox by adopting a dynamic and processual view of internationalization.
A surrogate FRAX model for Nepal
Authors: Johansson H. , Pandey D. , Lorentzon M. , Harvey N. C. , McCloskey E. V. , Kanis J. A.
Published: November 2024

Summary

A surrogate FRAX® model for Nepal has been constructed using age- and sex-specific hip fracture rates for Indians living in Singapore and age- and sex-specific mortality rates from Nepal.

Introduction

FRAX models are frequently requested for countries with little or no data on the incidence of hip fractures. In such circumstances, the development of a surrogate FRAX model is recommended based on country-specific mortality data but using fracture data from a country, usually within the region, where fracture rates are considered to be representative of the index country.

Objective

This report describes the development and characteristics of a surrogate FRAX model for Nepal.

Methods

The FRAX model used the ethnic-specific incidence of hip fracture in the Indian community of Singapore, combined with the death risk for Nepal in 2015–2019. The number of hip fractures in 2015 and 2050 was estimated based on the United Nations’ predicted changes in population demography.

Results

The surrogate model gave similar hip fracture probabilities to estimates from Sri Lanka, India and Pakistan but lower 10-year fracture probabilities for men and women at older ages compared to the model for Singapore, reflecting a higher mortality risk in Nepal compared with Singapore. There were very close correlations in fracture probabilities between the Nepalese and the Singapore models (r> 0.995) so that the use of the Nepalese model had little impact on the rank order of risk, i.e. a person at the xth percentile of risk with one model will be at the xth percentile of risk with the other. It was estimated that 6897 hip fractures arose in 2015 in individuals aged 50 years and older in Nepal, with a predicted 3-fold increase expected by 2050, when 23,409 hip fractures are expected nationally.

Conclusion

The surrogate FRAX model for Nepal provides an opportunity to determine fracture probability within the Nepalese population and help guide decisions about treatment.
Different lenses on distributions and the integration of context knowledge in data-ing processes of primary school students
Authors: Frischemeier Daniel , Birk Lisa
Published: November 2024

Data-ing, understood as the verb accompanying the noun data, can describe multiple competencies related to a proficient handling of data and its representations. Previous studies highlight the importance of developing a more holistic perspective on data for young learners as well as the consideration and fruitful integration of context knowledge and statistical information in order to strengthen competences involved while data-ing. Although both topics are well-researched individually, studies that jointly consider these aspects remain scarce. This study, therefore, reports on findings from an exploratory qualitative study of data-ing processes of 31 German third-grade students (age 9–10) and investigates the lenses on distributions that the young learners adopt as well as the purposes for which they leverage their context knowledge. Additionally, the study further characterizes the integration of the young learners’ context knowledge while data-ing with regards to the sources of said context knowledge. For analysis, the interviews were videotaped, transcribed and analyzed with qualitative content analysis methods. The exploratory study showed that our young learners predominantly use a classifier view to interpret the distributions of numerical data, often rely on their context knowledge more than on provided data, use their context knowledge mostly to justify a claim and mostly integrate their context knowledge on a local, ego-centric level in data-ing processes.
Pain chronification risk assessment: advanced phenotyping and scoring for prediction and treatments tailored to individualized patient profile
Authors: Martuliak Igor , Golubnitschaja Olga , Chvala Lubos , Kapalla Marko , Ferencik Miroslav , Bubeliny Michala , Venglarcik Michal , Kocan Ladislav
Published: November 2024

Acute pain is a physiologic, protective life-important warning neurological signal indicating multi-level tissue modulations caused by a broad spectrum of health adverse events such as stress overload, mechanical trauma, ischemia–reperfusion, sterile and infection-triggered inflammation, single- and multi-organ damage, acute and chronic wounds, tissue remodeling and degeneration, amongst others. On the other hand, pain chronification results in a pathologic transformation from the protective pain signaling into persistent debilitative medical condition with severe consequences including but not restricted to phenotype-specific behavioral patterns, reduced quality of life, and cognitive and mood disorders. Who is predisposed to an increased vs. decreased pain sensitivity and to the pain chronification? The motivation of personalized medicine that “same size does not fit all” is getting obvious also for an advanced approach in algesiology. Consequently, an in-depth patient stratification is essential for the paradigm change in overall pain management from currently applied reactive medical services to the cost-effective predictive, preventive, and personalized medicine (PPPM/3PM) in primary (reversible damage to health and targeted protection against health-to-disease transition) and secondary (personalized protection against disease progression) care. To this end, specifically innovative concepts of phenotyping elaborated in this study play a crucial role in patient stratification for predicting pain-associated outcomes, evidence-based targeted prevention of the pain chronification, and creation of treatment algorithms tailored to individualized patient profiles.
Inclusive School Policies and Practices and the Well-Being of LGBTQ + Students in Portugal
Authors: Sousa Diana , Gato Jorge
Published: November 2024

Introduction

The school context can be particularly problematic for youth who identify as lesbian, gay, bisexual, trans, and queer or who hold other sexual and gender-minoritized identities (LGBTQ +). To address this issue, LGBTQ + inclusive policies and practices have been implemented in many schools around the world.

Methods

A cross-sectional sample of 989 LGBTQ + and cisheterosexual high school students residing in Portugal completed an anonymous online survey in 2020/21. Participants were asked about their perceptions of LGBTQ + inclusive policies and practices in their school, namely, an inclusive curriculum, comprehensive policies, and information and support regarding sexual orientation and gender identity in their school. We further examined associations between these perceptions and LGBTQ + student well-being (depression, resilience, and self-esteem).

Results

Perceptions of the existence of an inclusive school curriculum were lower among LGBTQ + students compared to their cisheterosexual peers. In addition, LGBTQ + students who perceived the curriculum as less inclusive were more likely to report higher levels of depression and lower levels of resilience and self-esteem.

Conclusions

The findings suggest that LGBTQ + students perceive the school curriculum to be less inclusive, and this is associated with poorer well-being.

Policy Implications

Concrete policies and practices that improve school climate and promote the well-being of LGBTQ + students are paramount. These may include awareness-raising activities for students and discussion of LGBTQ + issues in the classroom. Therefore, cultural competency training for school staff is essential.
Thermal studies on cryocooler thermal masses from 4 K to 300 K for MRI applications
Authors: Shetty Sushanth R. , Umaranikar Ruturaj A. , Kasthurirengan S. , Kumar Shiva
Published: November 2024

Gifford–McMahon (GM) cryocoolers are pivotal for maintaining the temperature of MRI magnets, necessitating regular servicing for optimal performance and longevity. This study explores the geometric dimensions and shapes of superconducting magnets utilized in MRI for system cooling. The investigation demonstrates that warm-up time is contingent on heat capacity rather than geometric shapes. As a result, the design of magnets can be customized to specific shapes and sizes in accordance with favorable conditions, given that warm-up time is solely dependent on heat capacity. The primary focus is to deliberately prolong the warm-up time of the magnet relative to the GM cryocooler, consequently minimizing service intervals. Laboratory evaluations explore the use of thermal masses equivalent to MRI magnets, employing typical materials such as copper and aluminum. These masses are cooled to 4 K and then subjected to different heating powers to evaluate warm-up characteristics. Various configurations and shapes of thermal masses are numerically studied for warm-up analysis. Comparative assessments between experimental results and simulations reveal that, for cylindrical thermal masses, 80 W heating power facilitates a 76% reduction in warm-up time compared to 20 W heating across all cases. In the exploration of different geometric thermal masses, aluminum demonstrates a remarkable 35% decrease in warm-up time compared to copper. A noteworthy finding emerges, indicating that warm-up time is contingent on heat capacity rather than geometric shapes. These insights hold substantial relevance, particularly in systems with large thermal capacities, such as superconducting magnets. The study contributes valuable knowledge to the optimization of GM cryocoolers for enhanced MRI magnet performance and extended operational life.
Optimization of Placement of Continuous Air Monitors in a Radiological Facility
Authors: Chakraborty Joy , Sureshkumar M. K. , Joshi M. , Anand S. , Kulkarni M. S.
Published: November 2024

The airborne concentration of radioactive materials in radiological facilities is primarily influenced by the ventilation system, air purification system, and emission sources. Continuous Air Monitors (CAMs) are installed in these facilities to monitor the activity concentration of radioactive aerosols during both routine operations and any malfunctioning conditions. Typically, CAM placement is determined by the direction of maximum airflow. However, aerosols do not always adhere to the behaviour of airstreams, raising concerns about the suitability of CAM placement. To address this issue, this study employs software that integrates aerosol dynamics with computational fluid dynamics to calculate the CAM Placement Parameter. This parameter is derived from the peak aerosol concentration and the lag time to reach the specified CAM location, indicating the relative merit of positioning CAMs in a radiological facility under varying ventilation rates. The findings suggest that the coupled aerosol-fluid dynamics model accurately predicts the optimal placement of CAMs in workplace environments, thereby minimizing occupational exposure.
From practice to theory: characterizing the gap in surgical simulation
Authors: Syed Shareef M. , Brian Riley , Rodriguez Natalie , Linn Marcia , Gutiérrez Kris , Boscardin Christy
Published: November 2024

Purpose

Simulation curricula continue to struggle with adequately preparing trainees for the operating room. One reason for this phenomenon may be the lack of application and enactment of learning and instructional theories into simulation curricular design and practice. Few educators have taken a reflective approach to understand how surgical simulation succeeds and fails to incorporate best practices for learning based on theory. As such, this study aims to examine simulation sessions to identify gaps in practice by nesting two key frameworks from general education into surgical simulation: learning integration and the cognitive apprenticeship model.

Methods

We conducted an observational qualitative study in which we recorded simulation sessions with fifteen trainees and surgeons and deductively applied components of the above frameworks to transcripts. Subsequently, we analyzed gaps in the transcripts with regard to the application of these frameworks as theoretical concepts informing the analysis and interpretation.

Results

We organized results around the four fundamental tenets of learning integration, with principles of the cognitive apprenticeship model explored to provide further units of analysis. In doing so, we identified that simulation instructors adequately modeled, coached, and scaffolded to enable early phases of learning integration. However, instructors less aptly enabled reflection and self-guided exploration, which are critical components of learning integration.

Conclusions

We found areas in which instruction diverged from ideal standards as informed by our theoretical frameworks, thus highlighting the importance of regular simulation review to ensure that well-designed and intentioned simulation curricula continue to reflect the best educational principles when enacted in practice.
Extraterritoriality's Empire: How Self-Determination Limits Extraterritorial Lawmaking
Authors: Criddle Evan J.
Published: November 2024

In recent years, a growing number of countries have courted controversy by regulating activities outside their borders. They have used extraterritorial lawmaking to cultivate competitive global markets, strengthen or weaken data privacy, combat foreign terrorism and military aggression, promote human rights abroad, and suppress political dissent at home. This Article explores whether extraterritorial lawmaking can be reconciled with the right to self-determination under international law. I argue that the right to self-determination entitles each national polity to determine the laws and institutions by which it is governed within its territory. Extraterritorial lawmaking violates the right to self-determination when it subjects peoples to legal norms they have not freely endorsed. This insight calls for a paradigm shift in how international lawyers evaluate extraterritoriality, with broad ramifications for legal theory and practice.
Rethinking extinction “crises”: The case of Asian songbird trade
Authors: Fiennes Sicily , Hardianto Novi , Ansari Silvi Dwi , Dwiyahreni Asri A. , Jackson Tom , Holmes George , Birchall Christoper , Hassall Christopher
Published: November 2024

Different stakeholders and actors frequently describe environmental challenges as ‘crises’. These crises are often wicked problems that are difficult to resolve due to the complex and contradictory nature of the evidence and knowledge systems surrounding them. Here, we examine a crisis narrative surrounding the IUCN-declared Asian Songbird Crisis (ASC), with its epicentre in Indonesia, where an extensive birdkeeping culture persists. We investigate how bird extinction is perceived by different actors, particularly conservation law enforcement and practitioners working in this space. We unravel local perspectives on the complex relationship between bird trade and extinction through one-to-one interviews and focus groups. Our examination reveals a diversity of attitudes to the ASC, with many law enforcement actors not recognising the crisis label. Market mechanisms result in complex shifts in harvesting pressure onto one or more closely related similar species. The findings challenge the prevailing notion that species extinction significantly affects wildlife trades, emphasising the plastic nature of trade and the coming and going of species fashions. By revealing the divergent views of actors on extinction and the ASC, we highlight the need for shared language, particularly the implications of the ‘crisis’ label, around species extinction.
Designing postcapitalist finance in Protocols for Postcapitalist Expression
Authors: Morgan William
Published: November 2024

Protocols for Postcapitalist Expression, the Economic Space Agency’s latest experiment in radical economic design, explores the possibility of designing a digitally native economy that is geared towards care, the arts, and the environment, and which not only refuses to give up on the financial frontiers of contemporary capitalism, but actively seeks to marshal them towards innovative ends. The architecture of a novel economic space comes into view through a set of protocols, which integrate economic information within a social value framework. This ‘Economic Space Protocol’ involves crafting a new grammar for economic information production processes that have traditionally been tied to competitive market behavior. This essay interrogates the place of finance in the book, emphasizing price discovery’s generativity with regards to information. What is necessary in the imagination of any postcapitalist future are radical design initiatives that contend with both the necessity and the limits of the price discovery process.
On the laminar solutions and stability of accelerating and decelerating channel flows
Authors: Linot Alec J. , Schmid Peter J. , Taira Kunihiko
Published: November 2024

We study the effect of acceleration and deceleration on the stability of channel flows. To do so, we derive an exact solution for laminar profiles of channel flows with an arbitrary, time-varying wall motion and pressure gradient. This solution then allows us to investigate the stability of any unsteady channel flow. In particular, we restrict our investigation to the non-normal growth of perturbations about time-varying base flows with exponentially decaying acceleration and deceleration, with comparisons to growth about a constant base flow (i.e. the time-invariant simple shear or parabolic profile). We apply this acceleration and deceleration through the velocity of the walls and through the flow rate. For accelerating base flows, perturbations never grow larger than perturbations about a constant base flow, while decelerating flows show massive amplification of perturbations – at a Reynolds number of

$500$

, properly timed perturbations about the decelerating base flow grow

$ {O}(10^5)$

times larger than perturbations grow about a constant base flow. This amplification increases as we raise the rate of deceleration and the Reynolds number. We find that this amplification arises due to a transition from spanwise perturbations leading to the largest amplification to streamwise perturbations leading to the largest amplification that only occurs in the decelerating base flow. By evolving the optimal perturbations through the linearized equations of motion, we reveal that the decelerating base flow achieves this massive amplification through the Orr mechanism, or the down-gradient Reynolds stress mechanism, which accelerating and constant base flows cannot maintain.
Non-Hermitian Chern number in rotating Rayleigh–Bénard convection
Authors: Zhang Furu , Xie Jin-Han
Published: November 2024

We show that rotating Rayleigh–Bénard convection, where a rotating fluid is heated from below, exhibits a non-Hermitian topological invariant. Recently, Favier & Knobloch (J. Fluid Mech., vol. 895, 2020, R1) hypothesized that the robust sidewall modes in rapidly rotating convection are topologically protected. By considering a Berry curvature defined in the complex wavenumber space, we reveal that the bulk states can be characterized by a non-zero integer Chern number, implying a potential topological origin of the edge modes based on the Atiyah–Patodi–Singer index theorem (Fukaya et al., Phys. Rev. D, vol. 96 2017, 125004; Yu et al., Nucl. Phys. B, vol. 916, 2017, pp. 550–566). The linearized eigenvalue problem is intrinsically non-Hermitian, therefore, the definition of Berry curvature generalizes that of the stably stratified problem. Moreover, the three-dimensional set-up naturally regularizes the eigenvector, avoiding the compactification problem in shallow water waves (Tauber et al., J. Fluid Mech., vol. 868, 2019, R2). Under the hydrostatic approximation, it recovers a two-dimensional analogue of the one which explains the topological origin of the equatorial Kelvin and Yanai waves (Delplace et al., Science, vol. 358, issue 6366, 2017, pp. 1075–1077). The non-zero Chern number relies only on rotation when the fluid is stratified, no matter whether it is stable or unstable. However, the neutrally stratified system does not support a topological invariant. In addition, we define a winding number to visualize the topological nature of the fluid. Our results represent a step forward for the topologically protected states in convection, but the bulk-boundary correspondence requires a further direct analysis for proof, and the robustness of the edge states under varying boundary conditions remains a question to be answered.
Status Hierarchies and Stigma Shifting in International Relations
Authors: Kim Claudia Junghyun
Published: November 2024

How do states as social actors cope with stigma-induced status anxiety? I propose the concept of “stigma shifting” as a way in which status-anxious states overcompensate for their stigma-induced inferiority and reaffirm their place in the world: by seeking identification with higher-status states and differentiation from lower-status states. In identifying with the desired group of states, stigmatized states engage in approval-seeking behavior and reaffirm their in-group status in areas where they feel discredited. In differentiating themselves from the undesired group, stigmatized states engage in distinction-seeking behavior, claiming their superiority over this “lesser” group in areas that gave rise to their status anxiety in the first place. Stigma shifting, in other words, allows a stigmatized state to take the role of a stigmatizer. To demonstrate the concept's depth and analytical utility, I draw on the case of East Asia in three disparate issue areas: colonial redress, nuclear disaster, and international order making. Japan, stigmatized in all three areas, has reaffirmed its status by shifting the stigma onto its significant but “lesser” others: China and Korea. Ultimately, stigma shifting solidifies status hierarchies in the world—not just the hierarchy as represented by the “Western” dominance of international society but also the regional hierarchies of the non-Western world.
Simulating nonlinear optical processes on a superconducting quantum device
Authors: Shi Yuan , Evert Bram , Brown Amy F. , Tripathi Vinay , Sete Eyob A. , Geyko Vasily , Cho Yujin , DuBois Jonathan L. , Lidar Daniel , Joseph Ilon , Reagor Matt
Published: November 2024

Simulating plasma physics on quantum computers is difficult because most problems of interest are nonlinear, but quantum computers are not naturally suitable for nonlinear operations. In weakly nonlinear regimes, plasma problems can be modelled as wave–wave interactions. In this paper, we develop a quantization approach to convert nonlinear wave–wave interaction problems to Hamiltonian simulation problems. We demonstrate our approach using two qubits on a superconducting device. Unlike a photonic device, a superconducting device does not naturally have the desired interactions in its native Hamiltonian. Nevertheless, Hamiltonian simulations can still be performed by decomposing required unitary operations into native gates. To improve experimental results, we employ a range of error-mitigation techniques. Apart from readout error mitigation, we use randomized compilation to transform undiagnosed coherent errors into well-behaved stochastic Pauli channels. Moreover, to compensate for stochastic noise, we rescale exponentially decaying probability amplitudes using rates measured from cycle benchmarking. We carefully consider how different choices of product-formula algorithms affect the overall error and show how a trade-off can be made to best utilize limited quantum resources. This study provides an example of how plasma problems may be solved on near-term quantum computing platforms.
On the importance of slow ions in the kinetic Bohm criterion
Authors: Geraldini Alessandro , Brunner Stephan
Published: November 2024

Between a plasma and a solid target lies a positively charged sheath of several Debye lengths

$\lambda _{D}$

width, typically much smaller than the characteristic length scale

$L$

of the main plasma. This scale separation implies that the asymptotic limit

$\epsilon = \lambda _{D} / L \rightarrow 0$

is useful to solve for the plasma-sheath system. In this limit, the Bohm criterion must be satisfied at the sheath entrance. A new derivation of the kinetic criterion, admitting a general ion velocity distribution, is presented. It is proven that, for

$\epsilon \rightarrow 0$

, the distribution of the velocity component normal to the target,

$v_x$

, and its first derivative must vanish for

$|v_x| \rightarrow 0$

at the sheath entrance. These two conditions can be subsumed into a third integral one after it is integrated by parts twice. A subsequent interchange of the limits

$\epsilon \rightarrow 0$

and

$|v_x| \rightarrow 0$

is invalid, leading to a divergence which underlies the misconception that the criterion gives undue importance to slow ions.
Self-organization of collisionless shocks: from a laminar profile to a rippled time-dependent structure
Authors: Gedalin Michael , Roytershteyn Vadim
Published: November 2024

A collisionless shock structure results from the nonlinear interaction between charged particles and electromagnetic fields. Yet, a collisionless shock is globally governed by the mass, momentum and energy conservation requirements. A stable shock structure must ensure that the fluxes of the conserved quantities are constant on average, and, therefore, is determined by this necessity. Here, we study an observed high upstream temperature high Mach number shock and show that the conservation laws cannot be fulfilled unless the shock is spatially inhomogeneous along the shock front and time-dependent.
Host genotype and infection status interact to shape microbiomes in Daphnia magna
Authors: Rajarajan Amruta , Decaestecker Ellen , Bulteel Lore , Walser Jean-Claude , Spaak Piet , Wolinska Justyna
Published: November 2024

Host–bacterial communities (microbiomes) are influenced by a wide range of factors including host genotype and parasite exposure. However, few studies disentangle temporal and host-genotype-specific variation in microbiome response to infection across several host tissues. We experimentally exposed the freshwater crustacean Daphnia magna to its fungal parasite Metschnikowia bicuspidata and characterized changes in host–bacterial communities associated with the parasite's development within the host. We used 16S rRNA gene sequencing to assess bacterial communities of the host (a) 24 h (‘initial parasite exposure’) and (b) 10 days (‘successful infection’) after exposure to a standard dose of M. bicuspidata spores, in host guts, body tissue (excluding guts) and whole individuals. We also investigated whether bacterial community responses to parasite exposure varied by host genotype.

Parasite exposure did not immediately alter host gut bacterial communities, but drove host-genotype-specific changes in the bacterial community composition of whole individuals. We validated that these changes were not driven by shifts in bacterial communities of the culturing medium, due to the addition of the parasite spore solution. Successful infection (i.e. the proliferation of M. bicuspidata spores in the host body) reduced alpha diversity and shifted abundance of dominant bacterial orders in the gut. Moreover, it induced a host-genotype-specific changes in body bacterial community composition. Overall, bacterial community responses to parasite exposure and subsequent infection are complex: they occur in a host-genotype-dependent manner, differentially at distinct timepoints after parasite exposure, and in specific host tissue.