bluuebunny/crossref_metadata_2025 huggingface dataset:
A Computerized Tomography-Based Analysis of Spinal Canal Diameter to Study Its Implication on Cervical Spine Stenosis in Western Indian Population: A Retrospective Study
Authors: Purohit Isha , Barath Sitaram , Verma Anjana , Modi Kanishk , Purohit Chelsi
Published: September 2024

Background The cervical spine is prone to various conditions necessitating early detection. Morphometric analysis through computed tomography (CT) scans plays a pivotal role in diagnosing and preventing severe diseases. This study focuses on understanding the morphometric details of the cervical canal in the West Indian population, addressing a geographical gap in existing literature. The primary objective of this study was to perform a morphometric analysis of the cervical spine to study the implications it can have on cervical canal stenosis in the West Indian population.

Materials and Methods This study utilizes imaging data from the CT database of 100 individuals (73 men and 27 women). Measurements such as transverse canal diameter, sagittal canal diameter, cross-sectional canal surface area (CSA), and vertebral body diameter (VBD) were collected and the Pavlov-Torg ratio (PTR) was calculated from C2 to C7.

Results Notable findings include significant differences in CSA and VBD between genders, while PTR indicated cervical damage in 40% of participants. Multinomial regression was applied which signified an association between weakness and PTR.

Conclusion This study can be used to highlight the CT scan's importance in studying bony structures and the call for more region-specific morphometric studies. The variations in morphometric parameters could provide insights into understanding the vulnerabilities of a population belonging to a particular geographic area, in our case, the West Indian population.
Dengue-Related Hemophagocytic Lymphohistiocytosis in an Adult: A Case Report and Brief Update
Authors: Dinkar Anju , Singh Jitendra , Kumar Nilesh , Kumar Kailash , Singh Santosh Kumar
Published: September 2024

Dengue virus is an arbovirus transmitted through the bite of infected Aedes mosquitoes. Many unusual clinical features are being reported in dengue. Dengue complicated with hemophagocytic lymphohistiocytosis (HLH) is a rare but potentially fatal condition. Here, we report an 18-year-old otherwise healthy female with dengue fever complicated with HLH. The diagnosis was made by fulfilling the clinical and laboratory criteria of HLH. She was managed successfully with a methylprednisolone pulse regimen. Our case highlights the importance of early recognition of complications and prompt treatment for a better outcome.
Gelfoam Granuloma Mimicking Brain Abscess Following Decompressive Craniotomy
Authors: Panigrahi Souvagya , Acharya Abhijit , Tomar Surya Pratap Singh , Mahapatra A. K. , Deo Rama Chandra , Tripathy Soubhagya Ranjan , Senapati Satya Bhusan
Published: September 2024

The use of adjuvants in brain surgery has increased. Artificial adjuncts are being used in neurosurgery frequently. These foreign materials may result in a foreign body reaction inside the normal brain tissue surrounding the areas of pathology. This material may mimic an abscess or tumor in their presentation and masquerade the magnetic resonance (MR) or computed tomography (CT) image as recurrence, abscess, or granuloma. We present a case of a 42-year-old woman with a history of hypertensive basal ganglia bleeding who was operated on in an emergency. Decompressive craniectomy and clot evacuation were carried out. A thin layer of Gelfoam was applied in the operated area. After 4 weeks, she was planned for cranioplasty where an oval soft to firm yellowish lesion was found at the site of the previous cavity of the evacuated clot, which was sent for biopsy and it was confirmed as a Gelfoam granuloma. Meticulous use of hemostatic agents in the form of small surgical or thin waferlike gelatin sponges should be used intraoperatively. Large-size Gelfoam and artificial agents can lead to foreign body–like granulation tissue formation in normal brain tissue and several complications like hydrocephalous, meningitis, and seizures. Peculiarities in this case include the following: Gelfoam granuloma is a very rare complication following cranial surgery, it was mimicking like an abscess, and the size of Gelfoam used intraoperatively should be a thin wafer coating the raw surface or in the cavity.
An Unusual Presentation of Chronic Subdural Hematoma—“Subdural Mud”
Authors: R. Arvind K.
Published: September 2024

Chronic subdural hematoma (SDH) is widely seen in neurosurgical practice, however, the incidence of calcification or ossification in chronic SDH is a rare finding with an incidence of 0.3 to 2.7%. We report a case of an 85-year-old male after having undergone a parietal burr hole craniectomy for left-sided chronic SDH at a hospital in his locality, presented with a drop in conscious level, Glasgow Coma Scale of 9/15 (E3V1M5) with left-sided hemiparesis. A computed tomography scan revealed a thick left subdural collection with multiple densities along with a right capsuloganglionic bleed with intraventricular extension, which was successfully and completely removed, with progressive clinical improvement. Intraoperatively, as the SDH had the consistency and color, like that of mud/clay with thick membranes, it is referred to as “subdural mud.” In our case, surgical intervention did improve the neurological and functional outcome of the patient which supports the fact that surgery is indicated in patients with calcified chronic SDH with acute or progressive neurological deterioration.
Immunoglobulin D-Lambda Multiple Myeloma Initially Presenting in the Sphenoid Sinus, Orbital Apex, and Skull Base: A Systematic Review with a Case Report
Authors: Chen Yihan , Liu Jianfeng , Zhao Jianhui
Published: September 2024

Objectives Multiple myeloma (MM) with initial manifestations in the sphenoid sinus, orbital apex, and skull base is exceedingly rare. A systematic review was conducted to investigate the epidemiology and advancements.

Methods Relevant cases were identified by searching CNKI, WanFang Data, CQVIP databases, PubMed, Embase, and Web of Science. Additionally, we present a case of IgD-λ (immunoglobulin D-lambda) MM with initial symptoms of dizziness, unilateral pain, blindness, and ophthalmoplegia, leading to a 4-month overall survival. Strictly based on PRISMA standards, we included and summarized existing cases and reflected our case.

Results Our systematic review includes 34 case reports, revealing 67.6% of patients initially presented with diplopia and 44.1% underwent endoscopic procedures, notably with only two cases of IgD-λ subtype. In our case, we performed an endoscopic wide trans-ethmoidal sphenoidotomy and biopsy of the skull base and orbital apex lesion. Postoperative pathology confirmed a highly active plasmacytoma, clinically diagnosed as IgD-λ MM with a TP53 deletion mutation and multiple extramedullary metastases. A range of diagnostic tools was employed, including hemoglobin, immunoglobulin, urinary protein analysis, positron emission tomography-computed tomography (CT), bone marrow cytology, and gene detection.

Conclusion The subtle clinical manifestations of IgD-λ MM in the paranasal sinuses and skull base hinder early diagnosis. There is a paucity of literature describing MM initially presenting in these locations. CT/magnetic resonance scans are necessary to identify characteristic bone destruction. An endoscopic approach is popular for tissue biopsy. Bone marrow biopsy with a smear, serum or urine protein electrophoresis, and immunofixation electrophoresis are crucial upon the appearance of target organ damage.
Radiological Insights into Acute Leukoencephalopathy with Restricted Diffusion (ALERD): A Case Series Analysis
Authors: Jayaramu Satwik , Doddamani Diwakar
Published: September 2024

Objectives The study aimed to investigate the clinical and radiological characteristics of acute leukoencephalopathy with restricted diffusion (ALERD) among pediatric patients presenting with acute encephalopathy, seizures, and fever.

Methods A retrospective analysis was conducted on 48 pediatric patients who underwent magnetic resonance imaging (MRI) between April 2022 and August 2023 at Bapuji Hospital, J.J.M. Medical College, Davanagere, Karnataka, India. Inclusion criteria comprised acute-onset encephalopathy, fever, seizures, and MRI evidence of acute subcortical white matter involvement. Clinical and radiological data were collected and analyzed to delineate ALERD characteristics.

Results Among the study cohort, 18.7% of cases met the diagnostic criteria for ALERD, predominantly affecting male children with a mean age of 32 months. Clinical presentations varied, including biphasic and monophasic courses. Two distinct patterns of brain involvement, diffuse and central-sparing, were identified. Laboratory abnormalities and differential diagnoses were elucidated, providing insights into distinguishing ALERD from other conditions. MRI, particularly diffusion-weighted imaging, emerged as a crucial tool for ALERD diagnosis, revealing characteristic restricted diffusion patterns.

Conclusion The study underscores the importance of recognizing ALERD as a distinct clinical-radiological syndrome associated with infections, aiding in timely diagnosis and management. Understanding the varied clinical presentations and radiological patterns enhances diagnostic accuracy, emphasizing the role of MRI in ALERD diagnosis. These findings contribute to a comprehensive understanding of ALERD, facilitating improved patient outcomes and prognosis.
Analysis of dynamic spillover effects between carbon emission rights price, renewable energy index, and electricity sector index in China
Authors: Ren Zheng Yu , Hsiao Cody Yu-Ling , Liao Chonghan , Chen Hsing Hung
Published: September 2024

The motivation for our study stems from the increasing complexity of spillovers between energy markets in the low-carbon energy transition and the important practical implications of ensuring a secure energy supply. In this paper, based on a time-frequency perspective, we use TVP-VAR-SV and network topology analysis to examine the dynamic linkages between China's carbon market, several renewable energy markets, and electricity markets. The results reveal asymmetric risk spillovers between markets over time, with an upward trend. The establishment of the national carbon market did not significantly change the inter-market risk structure, with the hydropower and wind markets being the main sources of risk, and the electricity and carbon markets being the main recipients of risk. Spillovers show delayed and cyclical effects, peaking within one week and lasting up to five weeks. Finally, the paper makes several suggestions for risk prevention in the energy market: strengthening ex-ante risk warning and monitoring in the energy market; formulating specific carbon market policies based on the specific relationship between the carbon market and different energy markets; and giving full play to the guiding role of the carbon price in the allocation of carbon resources.
Masked pretraining strategy for neural potentials
Authors: Zhang Zehua , Li Zijie , Barati Farimani Amir
Published: September 2024

We propose a masked pretraining method for Graph Neural Networks (GNNs) to improve their performance on fitting potential energy surfaces, particularly in water and small organic molecule systems. GNNs are pretrained by recovering the spatial information of masked-out atoms from molecules selected with certain ratios and then transferred and fine-tuned on atomic force fields. Through such pretraining, GNNs learn meaningful prior about the structural and underlying physical information of molecule systems that are useful for downstream tasks. With comprehensive experiments and ablation studies, we show that the proposed method improves both the accuracy and convergence speed of GNNs compared to their counterparts trained from scratch or with other pretraining techniques. This approach showcases its potential to enhance the performance and data efficiency of GNNs in fitting molecular force fields.
Impact of tip curvature and edge rounding on the plasmonic properties of gold nanorods and their silver-coated counterparts
Authors: Vernier Charles , Portalès Hervé
Published: September 2024

Colloidal solutions of gold nanorods and silver-coated gold nanorods were prepared. The seeded growth synthesis protocols were improved by adding a flocculation purification step. The resulting populations of pure gold nanorods and Au@Ag core–shell cuboids were characterized by very low dispersion in size and shape. UV–vis–near-infrared absorption measurements were performed on several batches of well-calibrated nano-objects, supported by calculations based on the discrete dipole approximation, allowed to highlight the impact of various morphological features on the optical response. In addition to the well-known effect of the nanorod aspect ratio on the shift of the longitudinal surface plasmon resonance mode, special attention was paid to changing either the rounding of the nanorod end-caps or that of the edges of the coating silver shell. Nanorods and cuboids were modeled as superellipsoids. This approach enabled us to model precisely their complex shapes using just a few simple parameters and analyze the evolution of their extinction spectra as a function of the rounding of their tips and edges. Such nano-objects are widely used for various applications in fields such as biomedical, biosensing, or surface-enhanced Raman spectroscopy, thus making it crucial to precisely assess the impact of each morphological feature for optimizing their performance.
Active Brownian information engine: Self-propulsion induced colossal performance
Authors: Rafeek Rafna , Mondal Debasish
Published: September 2024

The information engine is a feedback mechanism that extorts work from a single heat bath using the mutual information earned during the measurement. We consider an overdamped active Ornstein–Uhlenbeck particle trapped in a 1D harmonic oscillator. The particle experiences fluctuations from an inherent thermal bath with a diffusion coefficient (D) and an active reservoir, with characteristic correlation time (τa) and strength (Da). We design a feedback-driven active Brownian information engine (ABIE) and analyze its best performance criteria. The optimal functioning criteria, the information gained during measurement, and the excess output work are reliant on the dispersion of the steady-state distribution of the particle’s position. The extent of enhanced performance of such ABIE depends on the relative values of two underlying time scales of the process, namely, thermal relaxation time (τr) and the characteristic correlation time (τa). In the limit of τa/τr → 0, one can achieve the upper bound on colossal work extraction as ∼0.202γ(D+Da) (γ is the friction coefficient). The excess amount of extracted work reduces and converges to its passive counterpart (∼0.202γD) in the limit of τa/τr → high. Interestingly, when τa/τr = 1, half the upper bound of excess work is achieved irrespective of the strength of either reservoirs, thermal or active. Finally, we look into the average displacement of active Brownian particles in each feedback cycle, which surpasses its thermal analog due to the broader marginal probability distribution.
Predictive modeling of MRR, TWR, and SR in spark-EDM of Al-4.5Cu–SiC using ANN and GEP
Authors: Debnath Shantanu , Sen Binayak , Patil Nagaraj , Kedia Ankit , Mann Vikasdeep Singh , Santhosh A. Johnson , Bhowmik Abhijit
Published: September 2024

In this study, Al-4.5Cu alloy was reinforced with varying weight percentages of SiC particles (2%, 4%, 6%, and 8%) to create metal matrix composites via the stir casting method. The formation of intermetallic compounds was confirmed through energy dispersive spectroscopy and x-ray diffraction analysis. This article compares the performance of Artificial Neural Network (ANN) and Gene Expression Programming (GEP) models in predicting the Metal Removal Rate (MRR), tool wear rate, and surface roughness in the die-sinking electro-discharge machining (EDM) process of the ex-situ developed Al-4.5%Cu–SiC composites. The study considers three machine parameters—pulse on time (TON), pulse off time (TOFF), and current (I)—along with the weight fraction of SiC particles as input variables for the models. Both ANN and GEP models demonstrated high predictive accuracy for the EDM performance metrics, with correlation coefficients (R) ranging from 0.973 68 to 0.980 65 for the ANN model and 0.980 11 to 0.982 59 for the GEP model. Notably, the GEP model exhibited superior predictive capability, as evidenced by its higher correlation coefficients and lower root mean square error, indicating greater effectiveness in predicting the EDM process outcomes than the ANN model.
A sociolinguistic study of the palatal fricative in Venezuelan Spanish
Authors: Díaz-Campos Manuel , Pollock Matthew
Published: September 2024

The Spanish palatal fricative /ʝ/, a site of considerable social variation, is examined in Caracas,
Venezuela, comparing productions across a 20-year period. Based on spectrographic and acoustic analyses, we identify
four allophones of the palatal fricative. While approximant use in Caracas has fallen from 1987–2013, it is still the
dominant allophone, and young speakers from the 2010s show increased use. Several linguistic factors, including
previous context, tonicity, and segment duration predict allophone production; however, social factors including
gender, corpus year, and speech rate suggest that stratification exists. Through a diachronic analysis, this study
provides insight into allophonic variation and social meaning in Caracas across two generations during a time of
sociopolitical change.
The present progressive as a future marker in Spanish, English, and Spanish in contact with English
Authors: Zahler Sara L. , Tolentino Rocío Leguisamon
Published: September 2024

We examined the acceptance of the present progressive (e.g., I am traveling) with
future meaning (PPF) by 82 monolingual English, monolingual Spanish, and heritage Spanish speakers. Participants
evaluated on a scale of 1–5 the acceptability of the PPF in 20 contexts that were embedded in a narrative in which we
manipulated the surrounding discourse for temporal reference, event certainty, and presence of a locative marker.
Results indicate that heritage Spanish speakers evaluated the PPF differently in English and Spanish, and differently
from both monolingual groups. These findings indicate that the effects of language contact in U.S. Spanish-English
bilinguals is bidirectional and that heritage Spanish speakers maintain two distinct systems for the PPF in Spanish
and English.
Ven, Vení, Venga
Authors: Vaughn Stevi , Ronquest Rebecca , Michnowicz Jim
Published: September 2024

The present investigation contributes to our understanding of the evolving linguistic communities
in the Southeastern U.S. by examining the factors that drive speakers’ choice of second person singular pronouns
(e.g., tú, vos, usted). Results indicate that context and origin are the most influential factors:
Argentines maintain their use of vos in familiar contexts, while Central Americans increase their use
of tú and usted over time. However, although Argentines maintain a higher use of
vos than Central Americans overall, they show evidence of accommodation to both
tú and usted in contexts where they interact with speakers of other Spanish
varieties. Qualitative analyses revealed an avoidance of voseo despite its strong ties to identity,
indicating a complex interplay between pronoun choice.
Spanish for specific purposes in the United States
Authors: Lafford Barbara A.
Published: September 2024

This article will provide an introduction to the field of Spanish for Specific Purposes (SSP) in
the United States (U.S.) (situated within a global context) and will discuss the advantages of SSP courses and
programs in U.S. university Spanish curricula. It will then provide an overview of trends in the development of the
SSP field in Europe, Latin America, and the U.S. by comparing the SSP faculty profiles, motivations for including SSP
in language curricula, theoretical frameworks underlying SSP research, research themes and domains studied in these
three geographic regions. Finally, the article will explore several major challenges to the field of SSP in the U.S.
and will propose solutions and future directions for addressing each challenge.
Immunomolecular and reactivity landscapes of gut IgA subclasses in homeostasis and inflammatory bowel disease
Authors: Tejedor Vaquero Sonia , Neuman Hadas , Comerma Laura , Marcos-Fa Xavi , Corral-Vazquez Celia , Uzzan Mathieu , Pybus Marc , Segura-Garzón Daniel , Guerra Joana , Perruzza Lisa , Tachó-Piñot Roser , Sintes Jordi , Rosenstein Adam , Grasset Emilie K. , Iglesias Mar , Gonzalez Farré Monica , Lop Joan , Patriaca-Amiano Maria Evangelina , Larrubia-Loring Monica , Santiago-Diaz Pablo , Perera-Bel Júlia , Berenguer-Molins Pau , Martinez Gallo Monica , Martin-Nalda Andrea , Varela Encarna , Garrido-Pontnou Marta , Grassi Fabio , Guarner Francisco , Mehandru Saurabh , Márquez-Mosquera Lucia , Mehr Ramit , Cerutti Andrea , Magri Giuliana
Published: September 2024

The human gut includes plasma cells (PCs) expressing immunoglobulin A1 (IgA1) or IgA2, two structurally distinct IgA subclasses with elusive regulation, function, and reactivity. We show here that intestinal IgA1+ and IgA2+ PCs co-emerged early in life, comparably accumulated somatic mutations, and were enriched within short-lived CD19+ and long-lived CD19− PC subsets, respectively. IgA2+ PCs were extensively clonally related to IgA1+ PCs and a subset of them presumably emerged from IgA1+ precursors. Of note, secretory IgA1 (SIgA1) and SIgA2 dually coated a large fraction of mucus-embedded bacteria, including Akkermansia muciniphila. Disruption of homeostasis by inflammatory bowel disease (IBD) was associated with an increase in actively proliferating IgA1+ plasmablasts, a depletion in long-lived IgA2+ PCs, and increased SIgA1+SIgA2+ gut microbiota. Such increase featured enhanced IgA1 reactivity to pathobionts, including Escherichia coli, combined with depletion of beneficial A. muciniphila. Thus, gut IgA1 and IgA2 emerge from clonally related PCs and show unique changes in both frequency and reactivity in IBD.
Effect of traps and conductive pathways on electron emission from copper broad-area composite emitters
Authors: Alsoud Ammar , Mousa Marwan S , Al-Bashaish Saleh R , Maghrabi Mufeed , Al-Jbarart Aseel A , Ronoh Kipkurui , Sedlařík Marek , Jaber Ahmad M D (Assa’d) , Abuamr Adel M , Telfah Ahmad , Trrad Issam , Sedlak Petr , Knápek Alexandr , Sobola Dinara
Published: September 2024

This study investigates electron emission from copper broad-area emitters (CBAEs) and copper broad-area composite emitters (CBACEs) based on the principles of trapping and conductive pathways. Emission current measurements were conducted on two CBACEs, which consisted of copper coated with a 300–400 μm epoxy resin and subjected to high voltages up to 15 kV. The research specifically examines the ‘switch-on’ and collapse phenomena occurring within the epoxy layer. Field emission microscopy (FEM) was utilized in a high-vacuum environment (

10

−
6

mbar) to observe these effects. A comprehensive model is developed to explain the formation of conductive pathways within the epoxy layer, allowing electrons transfer from traps to the surface. This model treats the composite emitter as a trap-rich capacitor. The study also clarifies the effects of trap density and epoxy layer thickness on the collapse process. To gain a deeper understanding of the model, changes in the I-V curve were examined. Simulations, scanning electron microscopy-energy dispersive x-ray spectroscopy (SEM-EDX) images, and Fourier transform infrared spectroscopy (FTIR) analysis were employed to understand the collapse mechanism of the epoxy collapse. Additionally, Nyquist and Cole–Cole plots were analyzed across frequencies ranging from 1 to

10

6

Hz before and after applying a high electric field on the samples, revealing changes in the capacitive component and the role of diodes in the formation of conductive channels.
A comparative study of total and partial ionization cross sections, branching ratios and fragmentation patterns of XH4 (X = C, Si, Ge, Sn, Pb)
Authors: Song Yunliang , Ma Yuwei , Li Bowen , Chen Ximeng
Published: September 2024

The formation and decomposition of SnH4 has been recently reported using electron ionization mass spectrometry (J. Am. Soc. Mass Spectrom. 35 (2024) 1523 and J. Vac. Sci. Technol. A 41 (2023) 063209) due to its importance in tin contamination cleaning in extreme ultraviolet lithography. A comprehensive understanding of the fragment patterns of SnH4 requires total and partial ionization cross sections of SnH4. However, there is limited availability of experimental and theoretical ionization data for SnH4. We report the electron-impact ionization fragmentation patterns of XH4 (X = C, Si, Ge, Sn, Pb) and should provide missing data, especially for SnH4 and PbH4. Total ionization cross sections are calculated using the Binary Encounter Bethe (BEB) method. Partial ionization cross sections and branching ratios are determined using mass spectrum data (MSD) and Huber et al’s method. Finally, we compare the calculated percentage abundances for the fragments of XH4 with experimental measurements.
Fano mode based plasmonic sensor for temperature and chemical pollutant detection
Authors: Yadav Gaurav Kumar , Metya Sanjeev Kumar
Published: September 2024

Plasmonic sensors provide great sensitivity to minute quantities of analytes and provide excellent detection. In present context of environmental monitoring, plasmonic sensor can prove to be an excellent choice in chemical pollutant and temperature detection. Plasmonic sensors can provide immediate results, allowing for monitoring temperature changes in ecosystems or climate studies and quick decision-making in emergency situations related chemical pollution incidents. They are compact and can be integrated into portable devices for on-site analysis. In this investigation, a plasmonic refractive index sensor based on key ring shaped resonator consisting of a microring resonator and two rectangular resonator is proposed. Finite-Difference Time-Domain (FDTD) method is used to study the transmittance characteristics of the sensor. The device exhibits quadruple Fano resonance with highest sensitivity of 2521.7 nm/RIU. Other performance parameters such as figure of Merit (FOM), Quality (Q) factor and Detection limit (DL) are also been calculated, with values 98.8 RIU−1, 99.6 and 0.01 respectively. Additionally, the effects of different geometrical configurations is also studied, providing insights into the design principles in context of potential fabrication complexities. Further, the simulated Fano characteristic is validated against the theoretical value. The application of the proposed sensor is investigated for different types of analyte such as chemical pollutants and temperature sensing.
Glimmers from the axiverse
Authors: Gendler Naomi , Marsh David J.E. , McAllister Liam , Moritz Jakob
Published: September 2024

We study axion-photon couplings in compactifications of type IIB string theory. We find
that these couplings are systematically suppressed compared to the inverse axion periodicity, as a
result of two effects. First, couplings to the QED theta angle are suppressed for axion mass
eigenstates that are light compared to the mass scale set by stringy instantons on the cycle
supporting QED. Second, in compactifications with many axions the intersection matrix is sparse,
making kinetic mixing weak. We study the resulting phenomenology in an ensemble of 200,000
toy models constructed from the Kreuzer-Skarke database up to the maximum Hodge number
h1,1 = 491. We examine freeze-in production and decay of thermal axions, birefringence of the
cosmic microwave background, X-ray spectrum oscillations, and constraints on the QCD axion from
supernovae. We conclude that compactifications in this corner of the landscape involve many
invisible axions, as well as a handful that may be detectable via photon couplings.
On the Riemann–Hilbert problem for the reverse space-time nonlocal Hirota equation with step-like initial data
Authors: Hu Bei-Bei , Zhang Ling , Shen Zu-Yi , Lin Ji
Published: September 2024

In this paper, we use the Riemann–Hilbert (RH) method to investigate the Cauchy problem of the reverse space-time nonlocal Hirota equation with step-like initial data: q(z, 0) = o(1) as z → −∞ and q(z, 0) = δ + o(1) as z → ∞, where δ is an arbitrary positive constant. We show that the solution of the Cauchy problem can be determined by the solution of the corresponding matrix RH problem established on the plane of complex spectral parameter λ. As an example, we construct an exact solution of the reverse space-time nonlocal Hirota equation in a special case via this RH problem.
Phase space analysis of interacting and non-interacting models in f(Q, C) gravity
Authors: Samaddar Amit , Singh Dr. Sanasam Surendra
Published: September 2024

Using a dynamical system method, we have studied a Friedmann-Robertson-Walker (FRW) cosmological model within the context of $f(Q,C)$ gravity, where $Q$ is the non-metricity scalar and $C$ represents the boundary term, considering both interacting and non-interacting models. A set of autonomous equations is derived, and solutions are calculated accordingly. We assessed the critical points obtained from these equations, identified their characteristic values, and explored the physical interpretation of the phase space for this system. Two types of $f(Q,C)$ are assumed to be $(i)$ $f(Q,C)=Q+\alpha Q+\beta C logC$ and $(ii)$ $f(Q,C)=Q+\alpha Q+\frac{\beta}{C}$, where $\alpha$ and $\beta$ are the parameters. In Model I, we obtain two stable critical points, while in Model II, we identified three stable critical points for both interacting and non-interacting models. We look into how the phase space trajectories behave at every critical points. We calculate the values of the physical parameters for both systems at each critical point, indicating the Universe's accelerated expansion.
Solving the relativistic Hartree-Bogoliubov equation with the finite-difference method*
Authors: Wang 王 Yiran 一然 , Cao 曹 Xiaojie 晓洁 , Hu 胡 Jinniu 金牛 , Zhang 张 Ying 颖
Published: September 2024

The relativistic Hartree-Bogoliubov (RHB) theory is a powerful tool for describing exotic nuclei near drip lines. The key technique is to solve the RHB equation in the coordinate space to obtain the quasi-particle states. In this paper, we solve the RHB equation with the Woods-Saxon-type mean-field and Delta-type pairing-field potentials by using the finite-difference method (FDM). We inevitably obtain spurious states when using the common symmetric central difference formula (CDF) to construct the Hamiltonian matrix, which is similar to the problem resulting from solving the Dirac equation with the same method. This problem is solved by using the asymmetric difference formula (ADF). In addition, we show that a large enough box is necessary to describe the continuum quasi-particle states. The canonical states obtained by diagonalizing the density matrix constructed by the quasi-particle states are not particularly sensitive to the box size. Part of the asymptotic wave functions can be improved by applying the ADF in the FDM compared to the shooting method with the same box boundary condition.
Capability of Searching for Kilonova Associated with a Short Gamma-Ray Burst by SVOM
Authors: Wang J. , Xin L. P. , Qiu Y. L. , Lan L. , Xie W. J. , Jin Z. P. , Wei J. Y.
Published: September 2024

In spite of the importance of studying the cosmic generation of heavy elements through the r-process, the detection of a kilonova resulting from the merger of a neutron star binary is still a challenging task. In this paper, we show that the Visible Telescope (VT) onboard the ongoing SVOM space mission is powerful for identifying kilonova candidates associated with short gamma-ray bursts up to a distance of 600 Mpc. A significant color variation, turning blue and then turning red, is revealed by calculating the light curves in both red and blue channels of VT by a linear combination of an afterglow and an associated kilonova. The maximum color variation is as high as ∼0.5–1 mag, which is far larger than the small photometry error of ∼0.2 mag of VT for a point source with a brightness of 23 mag. Up to a distance of 600 Mpc, ∼1–2 kilonova candidates per year are predicted to be identified by VT.
Single-pulse Emissions of PSRs J1611–0114 and J1617+1123
Authors: Liu Shifang , Wen Zhigang , Wang Shuangqiang , Kou Feifei , Yan Wenming , Yuan Jianping , Wu Qingdong , Zhao De , Miao Chenchen , Wang Na , Xue Menyao , Li Di , Wang Pei , Sun Shengnan , Zhu Weiwei , Bai Juntao
Published: September 2024

In this paper, the emissions from two pulsars, PSRs J1611−0114 and J1617+1123, were investigated using the Five-hundred-meter Aperture Spherical radio Telescope operating at a central frequency of 1250 MHz. The average pulse profile of PSR J1611−0114 shows two components, the first of which is relatively weak in intensity. The two-dimensional pulse stack exhibits an obvious nulling phenomenon, with an estimated nulling fraction of 40.1% ± 5.4%. The durations of the nulls and bursts are consistent with power-law distributions, and no periodic nulling phenomenon is found. The results from PSR J1617+1123 demonstrate that the average pulse profile is composed of four components. The peak intensity of the fourth component varies significantly, causing an unstable integrated profile. In addition, the modulation characteristics of J1611−0114 and J1617+1123 were studied by analyzing the modulation index, longitude resolved fluctuation spectrum and two-dimensional fluctuation spectrum using the software PSRSALSA. It was found that the two pulsars exhibit intensity modulation. In particular, J1611−0114 displays even–odd modulation, with the modulation period of approximately two pulses. The modulation period of J1617+1123 is relatively broad. There is an obvious subpulse drift phenomenon, and the value of P
2 is ∼0.125c/P
0, corresponding to 12 pulse longitude bins, and the drift rate (P
2/P
3) is about 0.29.
Measurement of average mass attenuation coefficient of air for 137Cs gamma-ray irradiation beam
Authors: Yi Chul-Young , Kim Yoon Ho , Kim In Jung , Park Jong In , Seong Young Min
Published: September 2024

The average mass attenuation coefficient of air for the KRISS 137Cs gamma-ray irradiation beam was measured using a 30 cm-long vacuum-sealable cylindrical column. Six different models of ionization chambers were employed for the measurement. Under ambient room conditions, the average mass attenuation coefficient was found to be (0.0778 ± 0.0012) cm2 g−1 across the six chambers. This coefficient will be used to adjust the variation in air kerma with air density for the 137Cs gamma-ray irradiation beam.
A shared robot control system combining augmented reality and motor imagery brain–computer interfaces with eye tracking
Authors: Dillen Arnau , Omidi Mohsen , Ghaffari Fakhreddine , Vanderborght Bram , Roelands Bart , Romain Olivier , Nowé Ann , De Pauw Kevin
Published: September 2024

Objective. Brain–computer interface (BCI) control systems monitor neural activity to detect the user’s intentions, enabling device control through mental imagery. Despite their potential, decoding neural activity in real-world conditions poses significant challenges, making BCIs currently impractical compared to traditional interaction methods. This study introduces a novel motor imagery (MI) BCI control strategy for operating a physically assistive robotic arm, addressing the difficulties of MI decoding from electroencephalogram (EEG) signals, which are inherently non-stationary and vary across individuals. Approach. A proof-of-concept BCI control system was developed using commercially available hardware, integrating MI with eye tracking in an augmented reality (AR) user interface to facilitate a shared control approach. This system proposes actions based on the user’s gaze, enabling selection through imagined movements. A user study was conducted to evaluate the system’s usability, focusing on its effectiveness and efficiency. Main results. Participants performed tasks that simulated everyday activities with the robotic arm, demonstrating the shared control system’s feasibility and practicality in real-world scenarios. Despite low online decoding performance (mean accuracy: 0.52 9, F1: 0.29, Cohen’s Kappa: 0.12), participants achieved a mean success rate of 0.83 in the final phase of the user study when given 15 min to complete the evaluation tasks. The success rate dropped below 0.5 when a 5 min cutoff time was selected. Significance. These results indicate that integrating AR and eye tracking can significantly enhance the usability of BCI systems, despite the complexities of MI-EEG decoding. While efficiency is still low, the effectiveness of our approach was verified. This suggests that BCI systems have the potential to become a viable interaction modality for everyday applications in the future.
Radiofrequency sheath rectification on WEST: application of the sheath-equivalent dielectric layer technique in tokamak geometry*
Authors: Tierens W. , Kumar A. , Klepper C. , Lore J. , Myra J.R. , Hillairet J. , Urbanczyk G. , Helou W. , Colas L. , Grosjean A. , Gunn J. ,   the WEST Team
Published: September 2024

Radiofrequency sheath rectification is a phenomenon relevant to the operation of Ion Cyclotron Range of Frequencies (ICRFs) actuators in tokamaks. Techniques to model the sheath rectification on 3D ICRF antenna geometries have only recently become available (Shiraiw et al 2023 Nucl. Fusion
63 026024; Beers et al 2021 Phys. Plasmas
28 093503). In this work, we apply the ‘sheath-equivalent dielectric layer’ technique, used previously only on linear devices (Beers et al 2021 Phys. Plasmas
28 103508), in tokamak geometry, computing rectified sheath potentials on the WEST ICRF antenna. Advancing the state of the art in sheath rectification modeling, we compute the sheath potentials not just on the limiters, but also on the Faraday Screen bars. The calculations show a peak rectified DC potential of 300 V on the limiters and 500 V on the Faraday screen. Assuming a typical sputtering yield curve, the RF sheath rectification increases the sputtering yield from the limiters by a factor of 2.6 w.r.t. the sputtering due to the non-rectified thermal sheath.
Simulation of DIII-D disruption with argon pellet injection and runaway electron beam
Authors: Zhao C. , Liu C. , Jardin S.C. , Ferraro N.M. , Lyons B.C.
Published: September 2024

The next generation of large tokamaks, including ITER, will be equipped with a disruption mitigation system (DMS) that can be activated if a disruption is deemed to be imminent. Introducing impurities by pellet (large or shattered) or massive gas injection has been shown to be an effective mitigation mechanism on many tokamaks. The goal of the mitigation is to lessen the thermal and electromagnetic loads from the disruption without generating enough high-energy (runaway) electrons to damage the device. Variations of this mitigation process with impurity injection are presently being tested on many experiments. We have modeled one such impurity injection experiment on DIII-D using the M3D-C1 nonlinear 3D extended MHD code (Jardin et al 2012 Comput. Sci. Discovery
6 014002), The model includes an argon large pellet injection and ablation model, impurity ionization, recombination, and radiation, and runaway electron formation and subsequent evolution, including both Dreicer and avalanche sources. We obtain reasonable agreement with the experimental results for the timescale of the thermal and current quench and for the magnitude of the runaway electron plateau formed during the mitigation. This is the first 3D full MHD simulation with pellets and REs to simulate the disruption process and it also provides a partial validation of the M3D-C1 DMS model.
Evolution of global water footprints of crop production in 1990–2019
Authors: Mialyk Oleksandr , Booij Martijn J , Schyns Joep F , Berger Markus
Published: September 2024

Crop production has the largest water footprint (WF) of all economic sectors and ranks as a leading cause of water scarcity. Despite this, our understanding of historical changes in global WFs of crops remains limited. In this study, we analyse the recently published dataset on green and blue WFs of 175 individual crops in 1990–2019. We explore the main changes in unit WFs (expressed in m3t−1 yr−1) and WFs of production (m3 yr−1) and connect the observed changes to various physical and socio-economic drivers. We find that nearly 80% of crops reduced global average unit WFs (required less water per tonne) as crop yields improved and cultivation centred around more productive areas. However, the total WF of crop production increased by 30% as these productivity gains were insufficient to compensate for cropland expansion of mostly water-intensive crops. Close to 90% of the increase occurred between 2000–2019 likely driven by accelerated economic growth, globalisation, changing diets, and production of first-generation biofuels. Among crops, we observe the largest increases for oil palm fruit, soya beans, and maize as they became the main providers of crop-based nutrients, animal feed, and biofuels for the modern economy. Among regions, most of the increase occurred across the tropics, mainly in Indonesia, Brazil, and Nigeria. However, India, China, and the USA had the largest WFs of production over the study period. Humanity consumed 6.8 trillion m3 of water (87.1% green) to produce crops in 2019. This number is likely to increase in the future which may exacerbate already existing environmental and socio-economic issues. Thus, it is important to transition to more water-sustainable agrifood systems. Much potential still exists in increasing crop water productivity, shifting production to less water-scarce geographies, and rethinking our dietary and industrial consumption patterns.
China’s carbon neutrality policy facilitates halving industrial water withdrawal
Authors: Li Zhe , Sun Fubao , Liu Wenbin , Wang Tingting , Wang Hong , Feng Yao
Published: September 2024

China concurrently confronts acute water resource challenges and substantial carbon emissions, with its industrial sector being a significant freshwater consumer and a primary carbon emitter. China has committed to achieving carbon neutrality (CN) by 2060, yet the exact impact of this goal on industrial water withdrawal (IWW) remains unclear. Here, we project IWW in China considering both scenarios with and without the CN target, based on industry-specific water quota standards and projections of industrial product output. Our findings indicate a 53.76% (51.41 km3) reduction of IWW by 2060 under a CN scenario, compared to business-as-usual, with the IWW peak advancing from 2035 to 2025. The thermal power industry holds the largest water withdrawal reduction, accounting for 75.74% (38.94 km3) of the total reduction. Additionally, both the East coastal region and the Middle Yangtze River region could reduce 62.08% (31.96 km3) of IWW under the CN scenario, with Jiangsu province emerging as a significant contributor. This study provides a reliable basis for evaluating the potential for future water withdrawal reduction within the industrial sector and suggests that achieving the CN target could offer a promising direction for alleviating China’s water scarcity challenges.
Stand characteristics regulate forest water use efficiency in the Three-North Shelterbelt Forest Program region of China
Authors: Pang Jianzhuang , Xu Hang , Zhang Qin , Zhang Yifan , Zhang Zhiqiang
Published: September 2024

The Three-North Shelter Forest Program (TNSFP) of China, one of the largest forestry ecological projects, serves as a nature-based solution to addressing ecological, social, and economic challenges and issues. This program, mainly situated in arid and semi-arid regions, critically focuses on improving water use efficiency (WUE)—maximizing carbon sequestration per unit of water consumed—as a key strategy for optimizing water resource utilization and ensuring the long-term success of vegetation restoration efforts. However, the regulatory mechanisms of forest WUE in this region remain unclear. Here, we adopted an interpretative machine-learning method to investigate the influence of main environmental elements, topographical conditions, and stand characteristics on forest WUE in the TNSFP region from 2001 to 2022 based on remote sensing products, ground monitoring data, and forest inventory data. Our study identified soil moisture (SM) as the primary factor influencing forest WUE across the TNSFP region, with higher SM levels generally leading to improved WUE in forests. However, stand characteristics strongly mediated their relationship. Specifically, forest WUE initially increases against forest density before peaking at about 1000 trees hm−2 for needle-leaved forests (NLF) and 800 trees hm−2 for broad-leaved forests, respectively, then gradually declining due to water competition. When SM is relatively adequate, moderate thinning could significantly enhance forest WUE. Furthermore, implementing management strategies to improve WUE is crucial as NLFs mature. This study emphasizes the significant impacts of stand characteristics on forest WUE in the TNSFP region, offering essential insights for optimizing water resource management in managed forests across arid and semi-arid regions.
Alteration of wetland resilience for the intermittently and permanently inundated wetland
Authors: Wu Jianfei , Liu Qiang , Liang Liqiao , Li Shuzhen , Gan Luoyang , Wu Haitao
Published: September 2024

Wetlands are influenced by the alteration of hydrological regimes induced by climate change and anthropogenic activity, affecting their structure and function. The resilience of wetlands under different hydrological status remains uncertain, which will bring risk to wetlands. To help understand the changes, this study employed the Normalized Difference Vegetation Index and early warning indicators to quantify wetland resilience across different climatic zones and compared the resilience of intermittently and permanently inundated wetlands. Furthermore, the shift of wetland resilience were explained using related meteorological variables. The results showed: (i) wetland resilience, theoretical recovery rates validated by empirical recovery rates, showed greater reliability in lag-one autocorrelation calculations (theoretical method), which were used to simulate wetland resilience across Northeast China; (ii) wetland resilience showed obvious geographical distribution trends along the climate regimes, which increased from arid to humid regimes; (iii) resilience of permanently inundated wetland was significantly higher than that of intermittently inundated wetland under the same climate regimes, indicating hydrological regimes play a vital role in affecting wetland integrity; and (iv) alteration of wetland resilience were explained by assuming that water, energy, and air temperature control wetland integrity. That is to say, that factors such as air temperature and radiation interact with hydrological regimes to affect wetland habitats. The alteration of wetland resilience brings new insight into wetland response to exogenous disturbances and the capacity for self-sustained stabilization, which will help address the impacts of climate change and anthropogenic activities.
Symmetry considerations in exact diagonalization: spin-1/2 pyrochlore magnets
Authors: Wei C , Curnoe S H
Published: September 2024

We describe how the methods of group theory (symmetry) are used to optimize the problem of exact diagonalization of a quantum system on a 16-site pyrochlore lattice. By analytically constructing a complete set of symmetrized states, the Hamiltonian can be completely block-diagonalized. As an example, we consider a spin-1/2 system with nearest-neighbour exchange interactions. We present the energy spectrum of a small system for a range of model parameters in the vicinity of the spin ice phase.