bluuebunny/crossref_metadata_2025 huggingface dataset:
Type-1 spinal muscular atrophy cohort before and after disease-modifying therapies
Authors: Alves Brenda Klemm Arci Mattos de Freitas , Araujo Alexandra Prufer de Queiroz Campos , Santos Flávia Nardes dos , Ribeiro Márcia Gonçalves
Published: November 2024

Background Spinal muscular atrophy (SMA-5q) is a neurodegenerative disease characterized by progressive muscle atrophy, hypotonia, and weakness, with SMA 1 presenting symptoms within the first 6 months of life. Disease-modifying therapies have been approved, with better outcomes with earlier treatment.

Objective To describe the safety and clinical efficacy of disease-modifying therapies based on SMN1 and SMN2 gene strategies concerning motor, respiratory, and bulbar function. Patients with SMA 1 were divided into 2 groups: those exclusively on nusinersen (group 1) and those transitioning to onasemnogene abeparvovec (OA) (group 2).

Methods Over 18 months, patients were assessed using the Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP-INTEND) scale, developmental milestones, ventilation needs and duration, nutritional support needs, consistency of food, and signs of dysphagia. There were ten patients, divided between the groups; in group 1, the average age for starting nusinersen was 53.6 (12–115) months, and, in group 2, the age was 7 (1–12) months for nusinersen and 15.2 (10–19) months for OA.

Results Our results indicate that 70% of patients reached some motor milestones, with group 1 increasing by 10.2 points on the CHOP-INTEND scale, while group 2 increased by 33 points. Additionally, 90% of the patients experienced no respiratory decline, and 30% maintained oral feeding. No serious adverse effects or deaths were recorded.

Conclusion Both groups showed improvement in motor function and stabilization of respiratory and bulbar function, with the difference between the groups possibly being related to the earlier treatment initiation. Thus, the present study provides valuable insights into the real-world safety and clinical efficacy of disease-modifying therapies for SMA 1 patients.
High-Grade Gastrointestinal Neuroendocrine Carcinomas: Multidisciplinary Approach Can Improve Survival Outcomes
Authors: Syed Noorzia , Ramaswamy Anant , Dhanawat Aditya , Joarder Ritam , Choudhary Jatin , Patel Dhwani , Bhargava Prabhat , Bal Munita , Yadav Subhash , Bhandare Manish , Chaudhari Vikram , Shrikhande Shailesh V. , Goel Mahesh , Patkar Shraddha , deSouza Ashwin , Saklani Avanish , Kazi Mufaddal , Puranik Ameya , Ostwal Vikas
Published: November 2024

Purpose There is limited evidence for the presentation patterns and outcomes of patients with high-grade gastrointestinal neuroendocrine carcinomas (HG-NEC).

Methods Patients diagnosed with HG-NEC, defined as having a pathological diagnosis of neuroendocrine cancer with an epicenter of cancer in the gastrointestinal tract and Molecular Immunology Borstel-1 index ≥ 20% between May 2014 and May 2022 were retrospectively analyzed for demographic variables, survivals, and prognostic parameters. The primary endpoint of the study was the estimation of median overall survival (OS) by the Kaplan–Meier method.

Results A total of 336 patients were included in the analysis, of whom 283 patients (84%) were started on cancer-directed treatment while 53 patients (16%) were planned for best supportive care. The most common sites of the primary were gallbladder (45%), colorectal (19%), and pancreas (13%), with 253 patients (75%) having metastatic NEC. All treated patients received systemic therapy (commonly platinum and etoposide), while 64 patients (23%) underwent resection of the primary. With a median follow-up of 65.4 (45.6 -85.3) months, the median OS of the entire cohort was 15.8 months. The prospective multidisciplinary tumor (MDT) board decision of classifying patients into resectable, unresectable, and metastatic HG-NEC was prognostic for OS (26.8 vs. 21.1 vs. 13.5 months; p = 0.001). Patients who were able to undergo multimodality therapy (resection and systemic therapy) had improved OS compared with patients on systemic therapy alone (23.1 vs. 14.9 months; p = 0.003).

Conclusion A majority of patients with HG-NEC present with advanced disease. An MDT is essential to deciding initial therapeutic strategies in these patients, with patients undergoing resection and systemic therapy having improved OS.
Emergent behaviors of relativistic flocks with adaptive coupling laws
Authors: Ahn Hyunjin
Published: November 2024

In this paper, we investigate the emergent behaviors of the relativistic Cucker–Smale (RCS) model equipped with adaptive couplings. To do this, we first divide adaptive couplings into two types, Hebbian or anti-Hebbian. For the Hebbian case, we demonstrate the asymptotic flocking of the RCS model in two ways based on the Lyapunov functional approach and continuous argument. Meanwhile, for the anti-Hebbian case, depending on the regularity of the adaptive law at the origin, we prove the various emergent behaviors such as the slow velocity alignment or the group formation.
Dispersive effects for the Schrödinger equation on finite metric graphs with infinite ends
Authors: Ali Mehmeti Felix , Ammari Kaïs , Nicaise Serge
Published: November 2024

We study the free Schrödinger equation on finite metric graphs with infinite ends. We give sufficient conditions to obtain the L1(R)→L∞(R) time decay rate at least t−1/2. These conditions allow certain metric graphs with circles and/or with commensurable lengths of the bounded edges. Further we study the dynamics of the probability flow between the bounded sub-graph and the unbounded ends.
Interference effects in commercially available free-space silicon single-photon avalanche diodes
Authors: Arabskyj L. , Dejen B. , Santana T. S. , Lucamarini M. , Chunnilall C. J. , Dolan P. R.
Published: November 2024

Single-photon avalanche diodes (SPADs) are essential for photon-based measurements and metrology, enabling measurement comparisons at the few-photon level and facilitating global traceability to the SI. A spatially uniform detector response is crucial for these applications. Here, we report on interference effects in commercially available silicon SPADs that are detrimental to their spatial uniformity. Contrasts as high as 18% are observed, posing problems for metrology and general applications that utilize coherent light and require stable detection efficiencies. We eliminate the device optical window as a contributing interface, isolating likely causes to anti-reflective coatings, the semiconductor surface, and the SPAD's internal structure. We also present results where we leverage this sub-optimal behavior by aligning an incident beam with the position of maximum constructive interference, yielding an effective detection efficiency of 51.1(1.7)% compared to the normal value of 44.3(1)% obtained with the interference suppressed. We anticipate that this work will significantly impact the continuing development of these devices, the methods for characterizing them, and their use in accurate measurements.
Dissipation in quantum tunnel junctions
Authors: Patiño Edgar J. , Rios E. L. , Kelkar N. G. , Lopez Daniel
Published: November 2024

Based on experimental data, we propose a model to evaluate the energy dissipated during quantum tunneling processes in solid-state junctions. This model incorporates a nonlinear friction force expressed in the general form f(x)=γv(x)α, where γ is the frictional coefficient, which is fitted to data. We study this by applying voltages just below the barrier height up to near breakdown voltages. Furthermore, by lowering the temperature and adjusting the applied voltage to the junction, the effect on dissipation caused by the variation in barrier height is examined. We underline that the crucial dependency of dissipation on the fraction of particle energy lost is modulated by two primary mechanisms: the application of voltage and the variation of temperature. The fraction of energy dissipated decreases, in general, for increasing energies of the tunneling particles at a given temperature. However, for a given energy of the tunneling particle, the present work demonstrates a turning point at a temperature of 137 K, after which the dissipated energy starts increasing for higher temperatures. The latter can possibly be due to the increase of electron–phonon interactions, which become predominant over barrier height reduction at higher temperatures, and hence, we identify T = 137 K as a critical temperature for a change in the dissipative characteristics of the solid-state junction under consideration. Notably, the study also identifies significant changes in dissipation parameters, γ and α, above 137 K, exhibiting a linear decline and underscoring the importance of further research at higher temperatures.
Double parametric based solution of fuzzy unconfined aquifer problem using Laplace transforms method
Authors: Sahoo Mrutyunjaya , Behera Diptiranjan , Chakraverty S.
Published: November 2024

The Boussinesq equation describes the model for horizontal water flow in unconfined aquifers without precipitation, a topic that has been extensively studied in the literature. However, the parameters, as well as the initial and boundary conditions, are often assumed to be exact. In reality, these conditions may be incomplete or uncertain due to limited knowledge, insufficient information, or errors introduced by humans or machines. The fuzzy set theory has recently been successfully employed to model such uncertainties. This article investigates the analytical solution of the one-dimensional Boussinesq equation in a fuzzy environment. The objective of this research is to investigate the recharge and discharge of a semi-infinite unconfined aquifer adjacent to a lake. For the present investigation, uncertainties in terms of fuzzy are considered only for the involved initial and boundary conditions of the problem, whereas other parameters are considered as crisp or exact. The analysis employed the double parametric form of a fuzzy number alongside Laplace transform techniques. The obtained solutions were then compared with existing results in specific cases to validate their accuracy.
An improved computational fluid dynamics-discrete bubble model for multiphase bubble flow simulation with a wide grid/bubble size ratio
Authors: Liu Zihan , Li Xiang , Zhou Du , Zhou Lianyong , Ma Huaqing , Luo Kun , Wang Zhixiong , Xu Chao , Zhao Yongzhi
Published: November 2024

The Euler–Lagrange method is a great way for multiphase bubble flow simulation, the detailed information of bubbles can be effortlessly obtained, and it is helpful for the efficiency and safety of different industry processes. Traditionally, the computational fluid dynamics-discrete bubble model (CFD-DBM) method has always been used to simulate this flow process. Nevertheless, the ability of the traditional CFD-DBM method is significantly limited in terms of the size ratio between the grid and bubble, where the grid size must be larger than the bubble size. In reality, the bubble may be larger than the grid and the grid/bubble size ratio can be very large due to the effects of complex bubble dynamics (such as the bubble breakup and coalescence) and complex internal flows. To address this issue, an improved CFD-DBM method is proposed in this study, which can be used for the simulation with a wide grid/bubble size ratio in gas–liquid–bubble multiphase simulation, and the volume of fluid (VOF) method is applied to capture the interface between gas and liquid phases. A gradient-based interpolation method is employed to reconstruct the liquid velocity around the target bubble when the grid size is much larger than the bubble size. If the bubble size is comparable with or larger than the grid size, the interphase force correction and the field smoothing will be carried out within a spherical support area. Subsequently, the proposed model is validated by the comparison with a bubble column experiment, in terms of the bubble size distribution and bubble vertical velocity. The results demonstrate the high accuracy of the new method. Finally, the influence of different parameters including normal spring stiffness, critical Weber number, and the range of the spherical support area on the bubble flow is investigated.
Impact of annular nanosecond plasma actuators on drag reduction in transonic flow
Authors: Sheibani Mohammad , Jafarian Seyyed Majid Malek , Abdollahzadehsangroudi Mohammadmahdi
Published: November 2024

During the last few decades, plasma actuators have emerged as promising devices for aerodynamic flow control. This study focuses on the use of nanosecond plasma actuators for such purposes. A thermal phenomenological model is employed to simulate the effects of these actuators. The propagation of shock waves and their interactions for two specific geometries of plasma actuators, linear and annular plasma synthetic jet actuators, are examined here. A comparative analysis of the performance of these two configurations is presented. Furthermore, the geometric characteristics and temperature model are analyzed to provide insights that can be applied to practical problems. The influence of the actuators on a projectile in the transonic flow is also investigated. The results of the present study show that actuators placed in the conical and cylindrical regions of the object do not contribute to drag reduction. Conversely, actuators positioned at the boat-tail and base of the object effectively reduce drag. This drag reduction is primarily attributed to thermal disturbances in the separation area. Additionally, it is observed that the effects of shock waves and their interaction with stationary waves around the projectile are negligible in terms of drag force reduction.
Velocity and area ratio effects on a coaxial impinging jet
Authors: Sun Haichao , Wang Xikun , Tao Xianming , Li Yalin
Published: November 2024

The formation of a circular water film by a coaxial liquid jet impinging onto a horizontal plate is a phenomenon largely unexplored in the literature. To investigate the effects of velocity ratio and area ratio on such coaxial impinging jets, a coaxial jet nozzle with an inner diameter of 2 mm and an outer diameter of 8 mm was designed. Experiments and numerical simulations were conducted using this nozzle. The experimental research employed high-speed photography to capture the circular water film formed by the coaxial jet impacting the plate. The influence of velocity ratios ranging from 0 to 0.28 was studied at a fixed inner jet flow rate. Numerical simulations were conducted with a constant outer-to-inner nozzle diameter ratio of 4, focusing on the effects of varying area ratio on the flow patterns of the coaxial impinging jet. The results demonstrate that the simulation strategy accurately predicts the radius of the circular water film, liquid film thickness, and wall shear stress. At a fixed inner jet flow rate, the water film radius increases with the velocity ratio, while the turbulence level within the film initially increases and subsequently decreases. Under a fixed total flow rate of 6 l/min, a larger area ratio leads to stronger interactions between the inner and outer jets, significantly impacting the coaxial jet structure, which is highly dependent on the velocity ratio. Similar to single jets, the coaxial jet exhibits good normalization and self-similarity after fully merged. The mutual interactions between the inner and outer jets of the coaxial impinging jet result in more bubbles in the water film, and a slower decay of wall shear stress than that of single jets, both of which are beneficial for surface cleaning.
Capillary filling dynamics in closed-end carbon nanotubes—Defying the classical Lucas–Washburn paradigm
Authors: Chaudhuri Abhirup , Arya Vinay , Bakli Chirodeep , Chakraborty Suman
Published: November 2024

The emergence of two-dimensional (2D) materials such as carbon nanotubes (CNTs) offers the possibility of exploring new regimes of capillarity and wetting that remained inaccessible with traditional microfluidic and nanofluidic substrates. Here, we bring out the non-intuitive capillary filling regimes in closed-end CNTs using molecular-level investigations. Contrary to the existing understanding of the advancing liquid meniscus getting retarded by the viscous resistance offered by an entrapped vapor phase in a three-dimensional capillary, here the liquid meniscus is shown to accelerate toward the later stages of the dynamic wetting, which is attributed to the modified surface friction due to a 2D interface. This apparently counterintuitive observation is qualitatively linked to the local pressure fluctuations across the meniscus caused by the spontaneous bombardment of the entrapped vapor molecules, which may ramify into hitherto unexplored phenomena of a shape-reversed meniscus advancing in the 2-D pore. We further develop a simple analytical model to represent the essential physics of the resulting capillary filling dynamics, featuring significant deviations from the classical Lucas–Washburn paradigm. These results may turn out to be imperative in realizing new regimes of capillarity in 2D materials in multifarious applications, ranging from energy storage and water filtration to thin film flows in integrated electronics and photonic devices.
Inhomogeneity-facilitated application of ferroelectric barium titanate thin films in artificial neuromorphic system
Authors: Wang Chenxi , Guo Lin , Hu Junjie , Li Titao , Zhuo Fangping , Wu Hong-Hui , Lu Xiaoqiang , Zhu Minmin
Published: November 2024

The growing interest in ferroelectric materials has witnessed the thriving prospect of bio-inspired artificial neuromorphic system, where multi-level polarization states play a crucial role. In this work, with typical BaTiO3 ferroelectric thin film as the model system, we explore the physical effects of inhomogeneity on polarization switching dynamics and neuromorphic performance. Inhomogeneous films exhibited pinched polarization–electric field hysteresis loops, leading to a high recognition accuracy of 96.03% for hand-written digits, compared to about 10.31% for homogeneous films. The inhomogeneity in switching dynamics was analyzed by inhomogeneous field mechanism. Diffusive distributions of switching time and local electric fields were observed, aligning with experimental results and the expected inhomogeneity. The prolonged domain wall depinning time and lowered energy consumption suggest the potential for multi-level polarization states, a possibility further confirmed by phase-field simulations that demonstrated their presence during long-term potentiation/depression. Our work highlights the positive influence of inhomogeneity in enhancing the performance of ferroelectric-based neuromorphic systems.
Dual magnetoelectric antenna array with enhanced bandwidth and sensitivity for low-frequency communications
Authors: Wang Yinan , Song Enzhong , Zi Guohao , Wang Yuanhang , Zhao Shanlin , Ma Zhibo
Published: November 2024

The magnetoelectric coupling effect demonstrated immense potential for miniaturizing antenna applications. However, due to the resonant nature of magnetoelectric (ME) antennas, their bandwidth tended to be relatively narrow. To address this limitation, our study introduced an array design based on coupled ME antennas. A tri-layer FeGa–PZT8–FeGa laminate structure was employed to construct the ME antennas, which utilized inter-array coupling to broaden the frequency range. Both the central frequency and sensitivity of the array structure were theoretically analyzed, and two methods for extending the frequency were proposed. By coupling two ME antennas of similar frequency in the series mode, the arrayed ME antennas exhibited enhanced sensitivity, increasing from 0.225 and 0.247 to 0.413 mV/nT, and an expanded bandwidth from 0.92–1.03 to 1.4 kHz, indicating improved performance through combined configuration. On the other hand, by coupling two ME antennas of different frequencies together in the series mode, a dual-frequency (97.8/98.97 kHz) ME antenna array was formed. The communication capabilities of the ME antenna array under weak magnetic fields were demonstrated using amplitude shift keying and frequency shift keying modulation methods. The designed array of ME antennas elevated low-frequency communication performance and possessed excellent magnetic field detection capabilities, thereby offering a cost-effective technological pathway for bioelectronic and marine communication design.
Tailoring the first law of thermodynamics for convective flows
Authors: Makuch Karol
Published: November 2024

Equilibrium thermodynamics is grounded in the law of energy conservation, with a specific focus on how systems exchange energy with their environment during transitions between equilibrium states. These transitions are typically characterized by quantities such as heat absorption and the work needed to alter the system's volume. This study is inspired by the potential to develop an analogous, straightforward thermodynamic description for systems that are out of equilibrium. Here, we explore the global energy exchanges that occur during transitions between these nonequilibrium states. We study a system with heat flow and an external (gravity) field that exhibits macroscopic motion, such as Rayleigh–Bénard convection. We show that the formula for system's energy exchange has the same form as in equilibrium. It opens the possibility of describing out-of-equilibrium systems using a few simple laws similar to equilibrium thermodynamics.
Diode characteristics of gas flow through conical nanochannels at atmospheric pressure
Authors: Zhang Yudong , Han Haoshi , Dou Shuaiwei , Wu Xiao , Qiu Jingjiang , Nie Bangbang , Wei Ronghan
Published: November 2024

Even at atmospheric pressure, non-continuum effects become noticeable in gas flow through nanoscale channels due to their extremely small dimensions. These effects result in diode-like behavior in the gas flow within conical nanochannel. This study combines experimental measurements with theoretical models to investigate the mass flow rate of gas through nanoscale conical channels under varying pressure ratios and channel sizes. The experimental results show that the diode effect becomes more pronounced as the aperture ratio and pressure ratio at the ends of the conical channels increase, in agreement with theoretical predictions. However, experimental measurements consistently yield significantly higher values. The strength of the gas flow diode is evaluated across a broad range of slip coefficients, characteristic dimensions, and pressure ratios. We propose that the diode effect arises from the interaction between discrete molecular effects and continuous flow dynamics, peaking when these two effects are in balance. In contrast, when one effect dominates, as seen in the regimes of free molecular flow or continuum flow, the diode effect diminishes. The gas diode behavior is primarily attributed from the varying scattering of molecules as they collide with the inclined channel walls.
Analysis of tunnel collapse mechanism due to dislocation and fracture of the surrounding rock block, and a method to predict the collapse height
Authors: Gao Xin , Liu Hongliang , Li Liping , Fan Hongyun , Li Shangan , Wang Shicheng
Published: November 2024

The boulders formed by cutting the structural surface of the hard rock tunnel may cause instability and disaster during excavation. The Universal Distinct Element Code numerical simulation was carried out based on 64 sets of orthogonal tests for the surrounding rock of the stratified and dislocated block fracture structure. Seven types of collapse modes were obtained for the stratified dislocated crack block structure. Some factors affecting the collapse height were quantitatively analyzed using the range analysis method. Also, six factors influencing the collapse height of a tunnel surrounding rock were ranked. In addition, a collapse height prediction model with six factors was developed for the surrounding rock around the tunnel. In order to analyze the collapse mechanism of the rock mass from the tunnel crack block, six sets of model tests were carried out for a rock mass with block crack stratified dislocation structure. Based on the optical flow method, the progressive evolution process of the rock mass instability induced by tunnel construction was studied, and the characteristics of sequence instability and the influence mechanism of multi-factor coupling of the block group were revealed. The simulation results were verified with the above six groups of laboratory simulation tests, and it was found that the accuracy of the prediction results was higher than 85.21%. It is expected that the results of the present research will provide a scientific basis for predicting, preventing, and controlling the collapse of the surrounding rocks during the construction of tunnels and underground caverns in the block fissure area.
A comprehensive functional trait database of seagrasses in tropical Queensland
Authors: Lin Chieh , Coles Robert G. , Rasheed Michael A. , Grech Alana
Published: November 2024

Context Seagrasses form an important habitat that provides diverse ecosystem services essential for both the environment and people. In tropical Queensland, Australia, these meadows hold significant economic and cultural value, serving as nurseries for marine species and sustaining dugongs and green turtles. The biomass and size of tropical seagrass meadows in Queensland varies considerably and are influenced by various factors, both biotic and abiotic. Aims Functional trait-based approaches can improve the estimation of seagrass-meadow resilience and services provision by describing the relationship between environment and individual performance. To support these approaches, we provide a seagrass functional-trait database focusing on resilience and function provision for tropical Queensland. Methods We employed a combination of literature reviews, database searches, botanical information, and structured expert elicitation to target 17 functional traits across 13 seagrass species in tropical Queensland. Key results We developed a traits database to inform functional trait-based approaches to assessing seagrass-meadow resilience and dynamics. The outputs included trait information for approximately 78% of the targeted traits (of 221 unique trait–seagrass combinations). Conclusions With current information on functional traits, we can improve the estimation of resilience and ecosystem services for tropical Queensland seagrass species. We have also highlighted trait data gaps and areas for further research. Implications We have provided examples of applying this database within the tropical Queensland context, with the potential to facilitate regional comparative studies. Our database complements existing plant-trait databases and serves as a valuable resource for future trait-based seagrass research in tropical Queensland.
Scale invariance in early embryonic development
Authors: Nikolić Miloš , Antonetti Victoria , Liu Feng , Muhaxheri Gentian , Petkova Mariela D. , Scheeler Martin , Smith Eric M. , Bialek William , Gregor Thomas
Published: November 2024

The expression of a few key genes determines the body plan of the fruit fly. We show that the spatial expression patterns for several of these genes scale precisely with embryo size. Discrete positional markers such as the peaks in striped patterns or the boundaries of expression domains have positions along the embryo’s major axis proportional to embryo length, accurate to within 1%. Further, the information (in bits) that graded patterns of expression provide about a cell’s position can be decomposed into information about fractional or scaled position and information about absolute position or embryo length; all information available is about scaled position, with

<

2% error. These findings imply that the underlying genetic network’s behavior exhibits scale invariance in a more precise mathematical sense. We argue that models that can explain this scale invariance also have a “zero mode” in the dynamics of gene expression, and this connects to observations on the spatial correlation of fluctuations in expression levels.
The Warburg Effect is the result of faster ATP production by glycolysis than respiration
Authors: Kukurugya Matthew A. , Rosset Saharon , Titov Denis V.
Published: November 2024

Many prokaryotic and eukaryotic cells metabolize glucose to organism-specific by-products instead of fully oxidizing it to carbon dioxide and water—a phenomenon referred to as the Warburg Effect. The benefit to a cell is not fully understood, given that partial metabolism of glucose yields an order of magnitude less adenosine triphosphate (ATP) per molecule of glucose than complete oxidation. Here, we test a previously formulated hypothesis that the benefit of the Warburg Effect is to increase ATP production rate by switching from high-yielding respiration to faster glycolysis when excess glucose is available and respiration rate becomes limited by proteome occupancy. We show that glycolysis produces ATP faster per gram of pathway protein than respiration in
Escherichia coli
,
Saccharomyces cerevisiae
, and mammalian cells. We then develop a simple mathematical model of energy metabolism that uses five experimentally estimated parameters and show that this model can accurately predict absolute rates of glycolysis and respiration in all three organisms under diverse conditions, providing strong support for the validity of the ATP production rate maximization hypothesis. In addition, our measurements show that mammalian respiration produces ATP up to 10-fold slower than respiration in
E. coli
or
S. cerevisiae
, suggesting that the ATP production rate per gram of pathway protein is a highly evolvable trait that is heavily optimized in microbes. We also find that
E. coli
respiration is faster than fermentation, explaining the observation that
E. coli
, unlike
S. cerevisiae
or mammalian cells, never switch to pure fermentation in the presence of oxygen.
Central place foragers, prey depletion halos, and how behavioral niche partitioning promotes consumer coexistence
Authors: Rueffler Claus , Lehmann Laurent
Published: November 2024

Many seabirds congregate in large colonies for breeding, a time when they are central place foragers. An influential idea in seabird ecology posits that competition during breeding results in an area of reduced prey availability around colonies, a phenomenon known as Ashmole’s halo, and that this limits colony size. This idea has gained empirical support, including the finding that species coexisting within a colony might be able to do so by foraging on a single prey species but at different distances. Here, we provide a comprehensive mathematical model for central place foragers exploiting a single prey in a two-dimensional environment, where the prey distribution is the result of intrinsic birth and death, movement in space, and mortality due to foraging birds (we also consider a variant tailored toward colonial social insects). Bird predation at different distances occurs according to an ideal free foraging distribution that maximizes prey delivery under flight and search costs. We fully characterize the birds’ ideal free distribution and the prey distribution it generates. Our results show that prey depletion halos around breeding colonies are a robust phenomenon and that the birds’ ideal free distribution is sensitive to prey movement. Furthermore, coexistence of several seabird species on a single prey easily emerges through behavioral niche partitioning whenever trait differences between species entail trade-offs between efficiently exploiting a scarce prey close to the colony and a more abundant prey far away. Such behavioral-based coexistence-inducing mechanism should generalize to other habitat and diet choice scenarios.
Mineral-associated organic matter is heterogeneous and structured by hydrophobic, charged, and polar interactions
Authors: Underwood Thomas R. , Bourg Ian C. , Rosso Kevin M.
Published: November 2024

The formation of mineral-associated organic matter (MAOM) is a key phenomenon that may explain the slow turnover rates of carbon in soil organic matter (SOM). Despite this, important details pertaining to the structure and dynamics of MAOM remain unknown. In the present study, we use replica-exchange molecular dynamics simulations to gain insight into the structure of MAOM on the surface of prototypical phyllosilicate clay and Fe-oxide minerals, montmorillonite and goethite, fine-grained minerals that strongly impact soil carbon dynamics in temperate and tropical regions, respectively. We examine the impact of aqueous chemistry through the presence of either Na

+

or Ca

2
+

charge balancing counterions. Our results are consistent with the hypothesized multilayer sorption (“onion-skin”) model of MAOM and help to explain previous observations regarding the patchy distribution of SOM on mineral surfaces. In particular, the SOM coatings are partial and laterally heterogeneous, and water retains extensive access to mineral surfaces even when significant SOM sorption occurs. Low molecular weight neutral SOM molecules (

<

200 Da) infrequently interact with the mineral surfaces nor their sorbed organic matter coatings and are increasingly labile with decreasing molecular weight. This observation is inconsistent with a central feature of the predominant soil continuum model of SOM and suggests that further iterations of the conceptual model may be required.
Reinforcement Learning for Efficient Identification of Soliton System Parameters Across Expansive Domains
Authors: Hu Cheng , Zhang Zhiyang , Liu Muwei , Xiang Liuyu , Wu Huijia , Liu Wenjun , He Zhaofeng
Published: November 2024

Optical solitons in mode-locked fiber lasers and optical communication links have various applications. The study of transmission modes of optical solitons necessitates the investigation of the relationship between the equation parameters and soliton evolution employing deep learning techniques. However, the existing identification models exhibit a limited parameter domain search range and are significantly influenced by initialization. Consequently, they often result in divergence toward incorrect parameter values. This study harnessed reinforcement learning to revamp the iterative process of the parameter identification model. By developing a two-stage optimization strategy, the model could conduct an accurate parameter search across arbitrary domains. The investigation involved several experiments on various standard and higher-order equations, illustrating that the innovative model overcame the impact of initialization on the parameter search, and the identified parameters are guided toward their correct values. The enhanced model markedly improves the experimental efficiency and holds significant promise for advancing the research of soliton propagation dynamics and addressing intricate scenarios.
Exploring fast domain wall motion and DMI realization in compensated ferrimagnetic nanowires
Authors: Mohammadi Mojtaba , Ranjbar Sina , Thach Pham Van , Sumi Satoshi , Tanabe Kenji , Awano Hiroyuki
Published: November 2024

Recent advancements in spintronics have spurred interest in current-induced domain wall motion as a promising avenue for next-generation memory technologies. While previous research has predominantly focused on thin ferromagnetic films, recent attention has shifted towards ferrimagnetic materials due to their potential for magnetization compensation and efficient domain wall (DW) motion. In this study, we investigated the dynamics of DWs in compensated ferrimagnetic Pt/Gd
x
Fe1−x
nanowires through experimental characterization and analysis. Our results reveal fast DW motion around the magnetic compensation point, indicating the influence of spin–orbit torque induced by current flow. We systematically explore the Dzyaloshinskii–Moriya interaction (DMI) field across different compositions of GdFe, observing elevated DMI field values near the compensation compositions. Additionally, we examine the impact of wire width and pulse duration on DW velocity, demonstrating higher velocities in narrower wires and shorter pulse durations. In the 1 μm wire, a DW velocity of around 3200 m s−1 was achieved by applying a 3 ns short pulse current. Our findings elucidate the intricate interplay between film composition, magnetic properties, wire width, pulse duration, and DW dynamics, providing valuable insights for the design and optimization of ferrimagnetic materials for future magnetic memory technologies.
Review of nonflow estimation methods and uncertainties in relativistic heavy-ion collisions
Authors: Feng Yicheng , Wang Fuqiang
Published: November 2024

Collective anisotropic flow, where particles are correlated over the entire event, is a prominent phenomenon in relativistic heavy-ion collisions and is sensitive to the properties of the matter created in those collisions. It is often measured by two- and multi-particle correlations and is therefore contaminated by nonflow, those genuine few-body correlations unrelated to the global event-wise correlations. Many methods have been devised to estimate nonflow contamination with various degrees of successes and difficulties. Here, we review those methods pedagogically, discussing the pros and cons of each method, and give examples of ballpark estimate of nonflow contamination and associated uncertainties in relativistic heavy-ion collisions. We hope such a review of the various nonflow estimation methods in a single place would prove helpful to future researches.
Investigating the impact of ITO substrates on the optical and electronic properties of WSe2 monolayers
Authors: Brito Thiago G L , Costa Fábio J R , Ceccatto Alisson , de Almeida Charles A N , de Siervo Abner , Couto Odilon D D , Barcelos Ingrid David , Zagonel Luiz Fernando
Published: November 2024

Two-dimensional (2D) materials, particularly transition metal dichalcogenides (TMDs), have gathered significant attention due to their interesting electrical and optical properties. Among TMDs, monolayers of WSe2 exhibit a direct band gap and high exciton binding energy, which enhances photon emission and absorption even at room temperature. This study investigates the electronic and optical properties of WSe2 monolayers when they are mechanically transferred to indium tin oxide (ITO) substrates. ITO is a transparent conducting electrode (TCE) used in many industrial optoelectronic applications. Samples were mechanically transferred under ambient conditions, consequently trapping an adsorbate layer of atmospheric molecules unintentionally between the monolayer and the substrate. To reduce the amount of adsorbates, some samples were thermally annealed. Atomic force microscopy confirmed the presence of the adsorbate layer under the TMD and its partial removal after annealing. X-ray photoelectron spectroscopy confirmed the presence of carbon species among the adsorbates even after annealing. Photoluminescence measurements show that WSe2 remains optically active on ITO even after annealing. Moreover, the luminescence intensity and energy are affected by the amount of adsorbates under the WSe2 monolayer. Scanning tunnelling spectroscopy reveals that the TMD monolayer is n-doped, and that its band edges form a type I band alignment with ITO. Surface potential measurements show a polarity change after annealing, indicating that polar molecules, most likely water, are being removed. This comprehensive study shows that a TCE does not quench WSe2 luminescence even after a prolonged thermal annealing, although its optical and electronic properties are affected by unintentional adsorbates. These findings provide insights for better understanding, controlling, and design of 2D material heterostructures on TCEs.
Doping- and capacitor-less 1T-DRAM cell using reconfigurable feedback mechanism
Authors: Suh Yuna , Lim Doohyeok
Published: November 2024

In this paper, we propose a doping- and capacitor-less 1T-DRAM cell, which achieved virtual doping by leveraging charge plasma and bias-induced electrostatic doping (bias-ED) techniques in a 5 nm-thick intrinsic silicon body, thereby eliminating doping processes. Platinum was in contact with the drain, while aluminum was in contact with the source, enabling virtual doping of the silicon body into a p*-i-n* configuration via the charge-plasma technique. Two coupled polarity gates and one control gate are positioned above the intrinsic channel region. The intrinsic channel region is virtually doped through the bias-ED by applying voltages to the gates, forming potential wells inside the channel. The voltage applied to the two coupled polarity gates determines whether the device operates in the p- or n-channel mode, whereas the control gate governs the flow of charge carriers. Charge carriers are stored and released in the potential wells inside the channel by adjusting the gate, effectively replacing the capacitor. In this device, the placement of polarity gates on either side of the control gate enables the observation of the reconfigurable characteristics. Moreover, the proposed device utilizes a feedback mechanism, enabling excellent memory characteristics such as a high on/off current ratio of ∼109, steep switching behavior of ∼0.2 µV dec−1, short write time of 10 ns, long hold retention of over 100 s, and long read retention of over 600 s.
Equilibrium measures on Julia sets of random quadratic polynomials
Authors: Lech Krzysztof , Zdunik Anna
Published: November 2024

We consider sequences of compositions of quadratic polynomials

f

c
n

(
z
)
=

z
2

+

c
n

. For such sequences one can naturally generalise the definitions of the Julia set and basin of infinity from the autonomous case. In this setting the Julia set depends on a sequence

ω
=
(

c
0

,

c
1

,

…

)

. We study the equilibrium (harmonic) measure on such Julia sets. In particular, we calculate the Hausdorff dimension of the equilibrium measure and study its dependence on the ‘scale of randomnes’.
Effects of spot size errors in DynamicARC pencil beam scanning proton therapy planning
Authors: Rana Suresh , Rosenfeld Anatoly B
Published: November 2024

Objective. Spot size stability is crucial in pencil beam scanning (PBS) proton therapy, and variations in spot size can disrupt dose distributions. Recently, a novel proton beam delivery method known as DynamicARC PBS scanning has been introduced. The current study investigates the dosimetric impact of spot size errors in DynamicARC proton therapy for head and neck (HNC), prostate, and lung cancers. Approach. Robustly optimized DynamicARC proton therapy plans were created for HNC (n = 4), prostate (n = 4), and lung (n = 4) cancer patients. Spot size errors of ±10%, ±15%, and ±20% were introduced, and their effects on target coverage (D
95% and D
99%), homogeneity index (HI), and organ-at-risk doses were analyzed across different cancer sites. Main Results. HNC and lung cancer plans showed greater vulnerability to spot size errors, with reductions in target coverage of up to 4.8% under −20% spot size errors. Dose homogeneity was also more affected in these cases, with HI degrading by 0.12 in lung cancer. Prostate cancer demonstrated greater resilience to spot size variations, even under errors of ±20%. For spot size errors ±10%, the oral cavity, parotid glands, and constrictor muscles experienced D
mean deviations within ±1.2%, while deviations were limited to ±0.5% for D
10% of the bladder and rectum and ±0.3% for V
20 Gy(RBE) of the lungs. The robustness analysis indicated that lung cancer plans were most susceptible to robustness reductions caused by spot size errors, while HNC plans demonstrated moderate sensitivity. Conversely, prostate cancer plans demonstrated high robustness, experiencing only minimal reductions in target coverage. Significance. While the ±10% spot size tolerance is appropriate in majority of the cases, lung cancer plans may require more stringent criteria. As DynamicARC becomes clinically available, measuring spot size errors in practice will be essential to validate these findings and refine tolerance thresholds for clinical use.
Verification of linear energy transfer optimized carbon-ion radiotherapy
Authors: Mizuno Hideyuki , Nakaji Taku , Lee Sung Hyun , Sakata Dousatsu , Aoki Katsumi , Mizushima Kota , Tran Linh T , Rosenfeld Anatoly , Inaniwa Taku
Published: November 2024

Objective. Linear energy transfer (LET) verification was conducted using a silicon-on-insulator (SOI) microdosimeter during the commissioning of LET-optimized carbon-ion radiotherapy (CIRT). This advanced treatment technique is expected to improve local control rates, especially in hypoxic tumors. Approach. An SOI microdosimeter with a cylindrical sensitive volume of 30 μm diameter and 5 μm thickness was used. Simple cubic plans and patient plans using the carbon-ion beams were created by treatment planning system, and the calculated LETd values were compared with the measured LETd values obtained by the SOI microdosimeter. Main results. Reasonable agreement between the measured and calculated LETd was seen in the plateau region of depth LETd profile, whereas the measured LETd were below the calculated LETd in the peak region, specifically where LETd exceeds 75 keV μm−1. The discrepancy in the peak region may arise from the uncertainties in the calibration process of the SOI microdosimeter. Excluding the peak region, the average ratio and standard deviation between measured and calculated LETd values were 0.996 and 7%, respectively. Significance. This verification results in the initiation of clinical trials for LET-optimized CIRT at QST Hospital, National Institutes for Quantum Science and Technology.
Performance of ITER pressure gauges during deuterium operation in the large helical device
Authors: Wenzel Uwe , Motojima Gen , Mackel Felix , Arkhipov Alexey , Jagielski Bartholomew , Haak Victoria , Meister Hans , Marquardt Mirko , Fox-Widdows Ella
Published: November 2024

During deuterium campaigns on the heliotron large helical device (LHD), ITER pressure gauges with different cathode materials were used to measure the neutral pressure in the sub-divertor region. Throughout these campaigns, it was observed that the performance of a LaB6 cathode was unsatisfactory during deuterium operation. Conversely, measurements taken with pressure gauges with a ZrC cathode performed well throughout the deuterium pulses. The ITER pressure gauge with the ZrC cathode could be operated with a very high electron current of 800 µA, thus improving the lower detection limit of the neutral pressure in LHD. With this design it was also possible to avoid jumps in the ion current within strong magnetic fields, improving the accuracy of the measurement from 15% uncertainty to 5%. These features allowed very precise neutral pressure measurements to be made in a fusion device with magnetic confinement. The problems with the lifetime of the ZrC cathode reported in Mackel et al (2023 Fusion Eng. Des.
189 113439) were not relevant here, as the total runtime in the magnetic field was about 60 h, less than the expected lifetime of the cathode of 350 h.
Application of a large wall electric probe (LWEP) for plasma and ambient gas studies
Authors: Demidov V I , Adams S F , Kurlyandskaya I P
Published: November 2024

The operation of a large wall electric probe (LWEP) is analyzed, where the probe surface area in contact with the plasma is only a few times smaller than the area of the plasma boundaries. Compared to a small standard Langmuir probe (SLP), the LWEP may have significantly greater resolution and sensitivity, but could substantially perturb the plasma and distort the measured properties. A target application for the LWEP is where the sensitivity of the measurement is critical, but the effects of the plasma perturbation is minimal. A specific case where a LWEP may outperform a SLP is the measurement of a nonlocal electron distribution function at energies of electron free diffusion, that is, at energies significantly exceeding thermal electron energies, in order to obtain information about the parameters of the plasma or ambient gas. Examination of the LWEP analysis process has revealed that, depending on the plasma volume and probe configurations, it may be necessary to measure either the first or second derivatives of the probe current with respect to the probe potential to derive the energetic part of the electron energy distribution function.