bluuebunny/crossref_metadata_2025 huggingface dataset:
Bessel beams generation with biphase transition of vanadium dioxide metasurface
Authors: Bo Hu , Wang Zhijian , Zhifang Qiu , Xinning Yu , Wang Xiaogang , Kaikai Huang , Mingli Sun , Xu Bijun
Published: July 2024

Bessel beams are highly attractive due to their non-diffraction properties, parallel processing capabilities, and large capacity. However, conventional methods for generating Bessel beams, such as using spatial light modulators, axicons, and diffraction optical elements, face limitations in terms of system complexity, bulkiness, low uniformity, and limited numerical aperture (NA). In this work, we exploited the phase change material vanadium dioxide (VO2) to generate both transmitted and reflected Bessel beams. Moreover, the self-healing property of Bessel beams was verified. Our results reveal that VO2 in the insulating state achieves a transmittance of 85% in the transmitting mode, while VO2 in the metallic state exhibits a reflection efficiency of 77% in the reflecting mode. This performance indicates the potential applications in efficient switchable metasurfaces.
A robust integrated navigation optimization method for USV in signal occlusion environment
Authors: Lou Naiyuan , Liu Wei , Hu Yuan , Wang Shengzheng , Han Bing
Published: July 2024

Unmanned surface vehicles (USV) can use global navigation satellite systems (GNSS) and inertial navigation systems (INS) for combined positioning and navigation. However, buildings such as port facilities and bridges blocking GNSS signals will increase the error in the discriminator output in the GNSS vector tracking loop and reduce positioning accuracy. Meanwhile, due to the cumulative error in the inertial navigation system, the credibility of the navigation results when the signal is blocked is further reduced. In this regard, this study proposes a robust integrated navigation optimization method. Specifically, the RTS smoothing optimized Kalman filter is used to constrain the carrier phase error and code phase error output by the discriminator, which can dynamically adjust the gain of the vector tracking loop, thereby improving the signal tracking capability. Simultaneously, the prediction results of the gated recurrent unit (GRU) network optimized based on the attention mechanism are combined with the inertial navigation system to improve navigation accuracy. Furthermore, an adaptive Kalman filter is utilized as the integrated navigation filter. The actual path of the carrier refers to the navigation solution of the existing receiver. In the open environment, the proposed optimization method reduces horizontal positioning error and speed error by 44.7% and 37.1% respectively compared with existing methods. Simultaneously, it can effectively improve the robustness of positioning in signal obstruction environments. The proposed integrated navigation method provides new possibilities for optimizing USV navigation solutions.
Density profiles in stellarators: an overview of particle transport, fuelling and profile shaping studies at TJ-II
Authors: Alonso J.A. , Alegre D. , Alonso J. , Antón R. , Arias-Camisón A. , Ascasíbar E. , Baciero A. , Barcala J.M. , Barnes M. , Blanco E. , Bueno L. , Bustos A. , Cabrera S. , de la Cal E. , Calvo I. , Cappa A. , Carralero D. , Carrasco R. , Carreras B. , Castro R. , de Castro A. , Cebrián L. , Chamorro M. , Chmyga A.A. , Colino P. , Duque J. , Escoto F.J. , Estrada T. , Fernández A. , Fraguas J. , Fontdecaba J.M. , Gabriel A. , García L. , García-Cortés I. , García-Gómez R. , García-Regaña J.M. , Godino-Sedano G. , Gómez-Manchón J. , González A. , González-Jerez A. , Guisse V. , Hernández-Sánchez J. , Hernanz J. , Hidalgo C. , Ivanova P. , Jiménez-Denche A. , Jiménez-Rey D. , Kocsis G. , Koepke M. , Kozachek A.S. , Lapayese F. , Liniers M. , López D. , López-Bruna D. , López-Miranda B. , de la Luna E. , Maragkoudakis E. , Martín-Díaz F. , Martín-Gómez G. , Martínez-Fernández J. , McCarthy K.J. , Medina F. , Medina-Roque D. , Medrano M. , Méndez P. , Miguel F.J. , van Milligen B. , Molinero A. , Motojima G. , Mulas S. , Navarro M. , Nedzelskiy I. , Nuñez R. , Ochando M. , Oyarzábal E. , de Pablos J.L. , Palomares F. , Panadero N. , Parra F.I. , Pastor C. , Pastor I. , de la Peña A. , Peralta R. , Pereira A. , Pons-Villalonga P. , Portas A.B. , Poveda E. , Ramos F.J. , Rattá G.A. , Redondo M. , Reynoso C. , Rincón E. , de la Riva J. , Rodríguez-Fernández C. , Ros A. , Sánchez E. , Sánchez J. , Sánchez-Sarabia E. , Sebastián J.A. , Solano E.R. , Soleto A. , Szepesi T. , Tabarés F.L. , Tafalla D. , Takahashi H. , Tamura N. , Thienpondt H. , Tolkachev A. , Tribaldos V. , Unamuno R. , Varela J. , Vega J. , Velasco J.L. , Voldiner I.
Published: July 2024

We provide an overview of activities carried out at the TJ-II stellarator for improving our understanding of- and developing plasma physics models for particle density profiles in stellarators. Namely, we report on recent progress in turbulent particle transport simulation, validation of pellet deposition models, density profile shaping for performance control and new experimental techniques for edge turbulence and plasma-neutral interaction.
Interpretive modeling of tungsten divertor leakage during experiments with neon gas seeding
Authors: Parsons Matthew S. , Sinclair Gregory , Abrams Tyler , Byrne Patrick , Chrystal Colin , Effenberg Florian , Herfindal Jeffrey L. , Odstrcil Tomas , Wilcox Robert S.
Published: July 2024

Many existing and future tokamaks with tungsten divertors operate, or will operate, with low-Z impurity seeding, but the direct effect of these seeded impurities on tungsten Scrape-off-Layer (SOL) transport has not been explored in detail. This paper reports on a DIII-D experiment designed to test how tungsten divertor leakage from the Small-Angle Slot V-Shaped, tungsten-coated divertor is impacted by neon seeding at a variety of injection rates and poloidal injection locations. Measurements from the experiment show an inverse relationship between the neon injection rate and the tungsten core penetration factor. Interpretive modeling is performed with a combination of the SOLPS-ITER and DIVIMP codes to assess the underlying tungsten behavior. The modeling results show that the reduction in tungsten divertor leakage is driven by both an increase in the divertor collisionality as well as a reduction in the ion temperature gradient near the divertor target. Collisions between low-Z impurities and tungsten impurities are found to have a significant impact on the tungsten SOL transport, such that ignoring the low-Z impurity collisional effects on the tungsten transport can result in an overestimate of the divertor leakage by an order-of-magnitude. Given the importance of these localized interactions, neon seeding from the closed, slot-like divertor has a clear advantage in being able to reduce tungsten divertor leakage without the high levels of neon core contamination that occur when seeding from other poloidal locations.
Exploring the suppression methods of helium-induced damage in tungsten by investigating the interaction between beryllium and helium
Authors: Zhou Hong-Bo , Li Jin-Liang , Lin Chaoxiang , Zhai Ya-Xin , Yang Zhangcan , Li Yu-Hao , Niu Yu-Ze , Ma Hui-Zhi , Lu Guang-Hong
Published: July 2024

Helium (He)-induced damage is a sensitive concern for the performance of tungsten plasma facing materials (W-PFMs). Recent experiments have revealed that trace impurities in He plasma can effectively prevent the formation of He bubbles and fuzz on W surfaces. To explore its plausibility and underlying mechanism, we performed a multiscale computational study that combines density functional theory calculations and object kinetic Monte Carlo simulations to investigate the effects of a small quantity of beryllium (Be) on the evolution of He bubbles. It is found that there is a strong attractive interaction between He and Be, which can be attributed to the decrease in electron density and the lattice distortion induced by embedded Be atoms. Therefore, the co-implantation of Be continuously introduces trapping centers for He. Due to the low implantation depth and high migration energy of Be, the Be atoms are located close to the surface, leading to the trapping of the majority of He within the near-surface region and the development of a shielding layer for He permeation. The presence of Be facilitates the dispersion of the trapped He, skewing the He clusters into smaller sizes. More importantly, the Be trapping centers bring the He clusters closer to the surface, significantly increasing the probability of bubble bursting and the release of He back to the vacuum. This ultimately leads to a lower retention of He in the case of He + Be co-irradiation, compared with the case of He-only irradiation. Consequently, our findings elucidate the suppressive effect of a low flux of Be atoms on the growth of He bubbles, highlighting the need to focus on synergetic effects between plasma species.
Counteracting sawtooth crash effects via fluctuation-induced inward transport in HL-2A NBI plasma
Authors: Wu Jie , Lan Tao , Ding Weixing , Wu Jiaren , Xu Min , Nie Lin , Chen Wei , Jiang Min , Huang Zhihui , Yi Kaiyang , Wu Na , Wang Weice , Zou Qian , Long Ting , Yuan Boda , Yu Liming , Yu Yi , Ke Rui , Xu Hangqi , Lu Pengcheng , Wang Tianxiong , Dong Qilong , Zhou Yongkang , Cai Hu , Deng Peng , Wang Xingkang , Bai Zeqi , Huang Yuhua , Chen Chen , Mao Wenzhe , Zhou Chu , Liu Ahdi , Wu Zhengwei , Xie Jinlin , Zhong Wulv , Duan Xuru , Liu Wandong , Zhuang Ge
Published: July 2024

The Langmuir probe observed an increase in density and floating potential fluctuations after the sawtooth crash at the edge of HL-2A neutral beam injection heated plasma. This process initiates fluctuating-induced radial inward particle transport once the plasma enters a period with strong sawtooth crash. The inward transport comprises broad-band fluctuations with varying scales, which occur uniquely in the immediate aftermath of the sawtooth crash-driven outflow, signifying a transient phenomenon confined to that specific interval. These results demonstrate that the sawtooth crash can significantly impact edge turbulence by modifying electrostatic fluctuations. This modification changes the direction of electric fluctuation-induced particle transport, thereby reducing the influence of the intense sawtooth crash-driven outflow. Furthermore, the observations support the existence of a damping mechanism for the outflow during the formation of inward flux after the sawtooth crash, which may be associated with the recovery process of sawtooth cycle.
Numerical analysis of tulip flame by dynamic mode decomposition
Authors: Joarder Ratan
Published: July 2024

Inversion of a premixed flame front to the shape of a tulip flower during the last stage of its propagation in a channel or tube of aspect ratio (AR) greater than two has intrigued the scientific community for decades. In the present work, the tulip inversion of hydrogen-air premixed flame is simulated numerically in two dimensional domains of AR 7.32, and 3.66. Dynamic Mode Decomposition is carried out on the two-dimensional pressure distribution obtained from the numerical simulation to understand the reasons behind the flame inversion. A plot of real and imaginary components of the eigenvalues over a unit circle clearly showed the presence of unstable acoustic modes during the tulip inversion for the domain of AR 7.32. The tulip inversion is not observed for the domain of AR 3.66. The distribution of the power and frequency of various modes are also plotted to identify the unstable modes. The present study shows generation of additional pressure waves during the tulip inversion process, which in term creates a velocity field that facilitates the flame inversion process.
Precedent and Open Texture
Authors: Horty John
Published: July 2024

This chapter presents a semantic account of open-textured predicates, particularly in the law, but also in language more broadly. The central idea is that judgments involving open-textured predicates are evaluated against a background set of previous authoritative decisions involving these predicates, which then constrain later applications in just the way that precedent cases constrain later decisions in the common law. In developing this idea, the paper relies on the “reason model” of precedential constraint, derived directly from recent research in artificial intelligence and law as well as previous work by Grant Lamond. According to the reason model, what matters about a precedent case is the court’s assessment of importance among the competing reasons presented by that case, which is represented as a priority ordering among these reasons. Later courts are then constrained simply to respect the priority ordering on reasons established by earlier decisions.
Constructive Responses to Bell’s Theorem
Authors: Stuckey W M , Silberstein Michael , McDevitt Timothy
Published: July 2024

Chapter 3 provides brief summaries of some popular constructive accounts of entanglement: Many-Worlds, superdeterminism, Bohmian mechanics, supermeasured theory, and retrocausality. It also introduces: relational quantum mechanics; complementary variables; and the relationship between dynamical laws, conservation principles, and entanglement.
Mystery Solved: Oh, the Irony
Authors: Stuckey W M , Silberstein Michael , McDevitt Timothy
Published: July 2024

Chapter 7 uses the ‘average-only’ projection for a qubit found in Chapter 6 to derive ‘average-only’ conservation for qubits entangled in Bell states. This is then used to derive the joint probabilities for particles entangled in Bell states, which map immediately to the mysterious facts of the Mermin device. Therefore, Mermin’s challenge is answered via ‘average-only’ conservation per NPRF. The symmetry of ‘average-only’ conservation in Bell states (highlighted in Chapter 0) is compared to the symmetry of length contraction and time dilation in the relativity of simultaneity for SR. So, contrary to popular opinion, QM and SR are more than compatible, they are both derived from NPRF such that their mysteries display the same kind of reference frame symmetry. The third experiment for the Poincaré symmetric ontology (photon polarization) is explained.
Monumental Ephemera: British Sculpture in the Arctic, Icebergs in London, an Inuit Map
Authors: Cheetham Mark A
Published: July 2024

The Arctic fascinated Londoners in the nineteenth century in panoramas, paintings and sculptures, voyage narratives and—tragically—transplanted Inuit. What has not been fully examined are the little-known amateur ‘snow sculptures’ of Britannia and other imperial figures made on a monumental scale in the Arctic in the early 1850s, when hundreds of sailors were searching for the lost 1845 Franklin expedition. Comparable with this crossing in sculpture is the amalgamation in one Parliamentary chart of an anonymous Inuk’s drawing of Franklin’s ships in the ice with a rendering of the area approved by the Admiralty. While these chiasmic interactions map a circuit of exchange, they also lack a centre. The most conspicuous absence in the Arctic was John Franklin, his crew and his two recently-recovered ships. In England, what was never ‘fixed’ was the idea of the Arctic.
Total syntheses of borolithochromes H1, H2, I1, and I2
Authors: Kirita Kanade , Matsumoto Hirotake , Endo Gaku , Inoue Keisuke , Hosokawa Seijiro
Published: July 2024

Total syntheses of borolithochromes H1, H2, I1, and I2, the red pigments isolated from fossils of Jurassic putative red alga Solenopora jurassica, have been achieved. The naphthoquinone possessing a chiral sec-butyl side chain has been synthesized from (S)-2-methylbutanol. The Diels-Alder reaction of the chiral naphthoquinone and the previously reported diene was followed by one pot S-methylation/intramolecular Corey-Chaykovsky reaction/epoxide rearrangement to provide the benzo[gh]tetraphene skeleton. Complexation of the resulting ligand with trimethyl borate and the following O-demethylation furnished a 1:1 mixture of borolithochromes I1 and I2, which were separated by HPLC using CHIRALPAK IC® to afford optically pure borolithochromes I1 (6) and I2 (7). On the other hand, borolithochromes H1 and H2 were not separated by HPLC in our laboratory. Fortunately, the mixture of the methyl ethers of borolithochromes H1 and H2 were separated and O-demethylation with magnesium iodide furnished optically pure borolithochromes H1 (4) and H2 (5).
BOK-engaged mitophagy alleviates neuropathology in Alzheimer’s disease
Authors: Yang Yang , Chen Hui , Huang Shuwen , Chen Hao , Verkhratsky Alexei , Niu Jianqin , Qu Yibo , Yi Chenju
Published: July 2024

Mitochondrial malfunction associated with impaired mitochondrial quality control and self-renewal machinery, known as mitophagy, is an under-appreciated mechanism precipitating synaptic loss and cognitive impairments in Alzheimer’s disease. Promoting mitophagy has been shown to improve cognitive function in Alzheimer’s disease animals. However, the regulatory mechanism was unclear, which formed the aim of this study.

Here, we found that a neuron-specific loss of Bcl-2 family member BOK in patients with Alzheimer’s disease and APPswe/PS1dE9 (APP/PS1) mice is closely associated with mitochondrial damage and mitophagy defects. We further revealed that BOK is the key to the Parkin-mediated mitophagy through competitive binding to the MCL1/Parkin complex, resulting in Parkin release and translocation to damaged mitochondria to initiate mitophagy. Furthermore, overexpressing bok in hippocampal neurons of APP/PS1 mice alleviated mitophagy and mitochondrial malfunction, resulting in improved cognitive function. Conversely, the knockdown of bok worsened the aforementioned Alzheimer’s disease-related changes.

Our findings uncover a novel mechanism of BOK signalling through regulating Parkin-mediated mitophagy to mitigate amyloid pathology, mitochondrial and synaptic malfunctions, and cognitive decline in Alzheimer’s disease, thus representing a promising therapeutic target.
Beyond the Timeline: 1-Year Mortality Trends in Early Versus Late Prosthetic Valve Endocarditis
Authors: Papadimitriou-Olivgeris Matthaios , Ledergerber Bruno , Siedentop Berit , Monney Pierre , Frank Michelle , Tzimas Georgios , Tozzi Piergiorgio , Kirsch Matthias , Epprecht Jana , van Hemelrijck Mathias , Dzemali Omer , Guery Benoit , Hasse Barbara
Published: July 2024

Among 302 episodes of prosthetic valve endocarditis (PVE), 1-year mortality was 31%. There was no evidence indicating that early-onset PVE within 6 months from valve surgery led to a worse outcome compared to late-onset PVE (21% vs 32%, P = .126), despite similar redo valve surgeries across both categories.
Genomic patterns in the dwarf kingfishers of northern Melanesia reveal a mechanistic framework explaining the paradox of the great speciators
Authors: DeRaad Devon A , Files Alexandra N , DeCicco Lucas H , Martin Rene P , McCullough Jenna M , Holland Piokera , Pikacha Douglas , Tigulu Ikuo G , Boseto David , Lavery Tyrone H , Andersen Michael J , Moyle Robert G
Published: July 2024

The paradox of the great speciators describes a contradictory biogeographic pattern exhibited by numerous avian lineages in Oceania. Specifically, these lineages display broad geographic distributions across the region, implying strong over-water dispersal capabilities; yet, they also display repeated genetic and phenotypic divergence—even between geographically proximate islands—implying poor inter-island dispersal capabilities. One group originally cited as evidence for this paradox is the dwarf kingfishers of the genus Ceyx. Here, using genomic sequencing and comprehensive geographic sampling of the monophyletic Ceyx radiation from northern Melanesia, we find repeated, deep genetic divergence and no evidence for gene flow between lineages found on geographically proximate islands, providing an exceptionally clear example of the paradox of the great speciators. A dated phylogenetic reconstruction suggests a significant burst of diversification occurred rapidly after reaching northern Melanesia, between 3.9 and 2.9 MYA. This pattern supports a shift in net diversification rate, concordant with the expectations of the “colonization cycle” hypothesis, which implies a historical shift in dispersiveness among great speciator lineages during the evolutionary past. Here, we present a formalized framework that explains how repeated founder effects and shifting selection pressures on highly dispersive genotypes are the only ultimate causes needed to generate the paradox of the great speciators. Within this framework, we emphasize that lineage-specific traits and island-specific abiotic factors will result in varying levels of selection pressure against dispersiveness, caused by varying proximate eco-evolutionary mechanisms. Overall, we highlight how understanding patterns of diversification in the Ceyx dwarf kingfishers helped us generate a cohesive framework that provides a rigorous mechanistic explanation for patterns concordant with the paradox of the great speciators and the repeated emergence of geographic radiations in island archipelagoes across the globe.
A rapid analysis of aftershock processes after a moderate magnitude earthquake with ML methods
Authors: Fonzetti Rossella , Govoni Aladino , De Gori Pasquale , Chiarabba Claudio
Published: July 2024

Moderate magnitude earthquakes and seismic sequences frequently develop on fault systems, but whether they are linked to future major ruptures is always ambiguous. In this study, we investigated a seismic sequence that has developed within a portion of the stretching region of the Apennines in Italy where moderate to large earthquakes are likely to occur. We captured a total of 2039 aftershocks of the 2023 September 18, Mw 4.9 earthquake occurred during the first week, by using machine-learning (ML) based algorithms. Aftershocks align on two 5–7 km long parallel faults, from a length that exceeds what is expected from the main shock magnitude. The segments are ramping at about 6 km depth on closely spaced N100 striking 70 N dipping planes, at a distance of some kilometres from the main shock hypocentre. Our results indicate that even moderate magnitude events trigger seismicity on a spread set of fault segments around the main shock hypocentre, revealing processes of interaction within the crustal layer. The possibility that larger earthquakes develop during seismicity spread is favoured by pore pressure diffusion, in relation with the closeness to criticality of fault segments. Based on the very rapid activation of seismicity on the entire system and a back-front signal from the hypocentre of the main event, we infer that fluid pressure, initially high within the crustal layer, rapidly dropped after the main shock. Our study reinforces the importance of timely extracting information on fault geometry and seismicity distribution on faults. ML-based methods represent a viable tool for semi-real-time application, yielding constraints on short-time forecasts.
Luteolin, a natural flavonoid, exhibits a protective effect on intestinal injury induced by soybean meal in early-weaned piglets
Authors: Liang Xuecong , Zheng Shugui , Zhou Yang , Li Jiguang , Zhang Zhuo
Published: July 2024

Soybean meal is known to be able to cause intestinal damage and dysfunction in early-weaned piglets. However, research on natural compounds that can alleviate these effects is scarce. In this study, the effect of luteolin, a natural flavonoid, on intestinal health of piglets fed on a soybean meal-based diet was explored. A total of eighteen 21-d-old piglets were selected and randomly divided into 3 groups: a negative control group fed with an animal protein-based diet, a positive control group fed with a soybean meal-based diet, and a luteolin group that was fed with the positive control diet supplemented with luteolin. The results suggested that luteolin supplementation significantly increased the average daily gain and average daily feed intake of early-weaned piglets, while effectively reducing the diarrhea incidence. Additionally, luteolin supplementation lowered the levels of soybean antigen-specific immunoglobulin G and immunoglobulin E anitbodies, increased the superoxide dismutase activity in both sera and small intestine mucosa, and enhanced the total antioxidant capacity in sera. Further research found that luteolin supplementation increased the intestinal villi height and decreased the crypt depth, resulting in an increased ratio of villi to crypts. At the same time, it reduced the concentration of serum diamine oxidase, improving intestinal barrier function. Moreover, luteolin significantly decreased the gene expression of Bax and Caspase-3, reducing cell apoptosis in the intestinal mucosa. Luteolin supplementation also increased the abundance of Actinobacteria at the phylum level, reduced the abundance of Prevotella and increased the abundance of Olsenella at the genus level. In conclusion, the supplementation of luteolin to the soybean meal diet was capable of effectively reducing allergic response, enhancing the antioxidant capacity of early-weaned piglets, protecting their intestinal barrier function, inhibiting intestinal mucosal cell apoptosis, and altering the intestinal microbiota structure, therefore promoting intestinal health and improving production performance in early-weaned piglets.
He Loves the One He Has Invested In: The Effects of Mating Cues on Men’s and Women’s Sunk Cost Bias
Authors: Chen Rui , Sun Hao , Guo Zhaoyang , Chen Haipeng (Allan)
Published: July 2024

The sunk cost bias, that is, people’s suboptimal tendency to continue to pursue previously invested options, has been found in many domains, and various mechanisms have been proposed. The current study offers a novel perspective for understanding sunk cost bias. Drawing on previous findings suggesting that sunk cost bias may be adaptive and promoted by fundamental motives, it is theorized that sunk cost bias may be a goal-oriented behavior in the mating domain and that this bias can extend to consumption domains (e.g., product/service with nonrefundable deposits, lotteries earned through prior effort, loyalty program memberships obtained through previous purchases) when mating cues are salient. One field study and seven experiments (six of which were pre-registered) demonstrated that mating cues strengthen an implemental mindset among men (vs. women). Consequently, men exhibit a stronger sunk cost bias in consumption when mating cues are salient. However, this effect was not found among women due to differences in their mating tactics. In addition, this article distinguishes sunk cost effect from status quo bias and rules out multiple alternative explanations for the results (including affect, overconfidence, the investment-payoff link, persistence, perceived morality, shame, guilt, and disgust associated with abandoning the original option).
Simulation study on the radioactive logging responses in the spiral borehole
Authors: Mi Honggang , Liang Yunan , Sun Qiang , Wei Chao , Song Hongwei , Zhang Quanying , Li Ningchao , Nie Xin
Published: July 2024

The spiral borehole, primarily attributed to uneven force on the drill bit, poses a unique drilling and well logging challenge. In certain logging applications, this phenomenon can disrupt logging responses, introducing periodic fluctuations in the logging curve and complicating the interpretation process. To elucidate the impact of the spiral-borehole phenomenon on conventional radioactive logging methods, we conducted a simulation study examining its effects on traditional density tool, thermal-neutron porosity tool, and natural gamma tool. Our findings reveal significant influences on density and porosity tool responses, with the amplitude of periodic fluctuations in logging curves closely linked to the groove depth of the spiral borehole. Conversely, the natural gamma tool exhibits minimal impact, with noticeable spiral-borehole effects causing limited fluctuations. Additionally, when the groove depth of the spiral borehole is fixed, the smaller the distance between the logging tool and the well wall, the closer the value obtained by the logging tool is to the true value of the formation parameter, and vice versa. This research offers theoretical insights for effectively correcting spiral-borehole effects in radioactive logging methods.
About two unusual cases of pancreatic primary squamous cell carcinoma
Authors: Boujida Ismail , Horache Kenza , Derqaoui Sabrine , Jahid Ahmed , Zouaidia Fouad , El-Aoufir Omar , Bernoussi Zakia , Znati Kaoutar
Published: July 2024

Pancreatic primary squamous cell carcinoma (PPSCC) is very uncommon. The major diagnostic method is histology, and it requires the exclusion of a metastasis from a different primary location (lung, esophagus…). Herein, we describe two cases of a PPSCC (one in the head and the other one in the tail and the body of the pancreas) with a brief review of literature. When it comes to the poorly differentiated PPSCC, immunohistochemistry (IHC) is crucial. Regretfully, there is currently no unanimity on treatment, and the outcome is dismal.
Phenylboronic acid interacts with pectic rhamnogalacturonan-II and displays anti-auxinic effects during Arabidopsis thaliana root growth and development
Authors: Hays Quentin , Ropitaux Marc , Gügi Bruno , Vallois Anthony , Baron Aurélie , Vauzeilles Boris , Lerouge Patrice , Anderson Charles T , Lehner Arnaud
Published: July 2024

Boron dimerizes rhamnogalacturonan-II (RG-II) in the plant cell wall and is crucial for cell elongation; however, studying RG-II dimerization is challenging because of the severe phenotypes or lethality of RG-II mutants. Boron deprivation negates both RG-II dimerization and plant growth, but whether or how these phenotypes are functionally linked has remained unclear. Boric acid analogues can serve as experimental tools to interfere with RG-II cross-linking. In this study, we treated Arabidopsis seedlings with the boric acid analogue phenylboronic acid (PBA) to examine whether the resulting developmental phenotypes were attributable to alteration of RG-II dimerization or to other putative functions of boron in plants. We found that PBA treatment altered root development in the seedlings while RG-II dimerization and its distribution were not affected. Surprisingly, under low boron conditions, PBA treatment had no effect on root size but still prevented lateral root development, and it restored RG-II dimerization. PBA treatment also disrupted auxin levels, potentially explaining the absence of lateral roots in the seedlings treated with this analogue. We conclude that PBA interacts both with RG-II and other cellular targets such as auxin signaling components, and that the phenotypes caused by PBA arise from interference with multiple functions of boron.
Stress-regulated Arabidopsis GAT2 is a low affinity γ-aminobutyric acid transporter
Authors: Meier Stefan , Bautzmann Robin , Komarova Nataliya Y , Ernst Viona , Suter Grotemeyer Marianne , Schröder Kirsten , Haindrich Alexander C , Vega Fernández Adriana , Robert Christelle A M , Ward John M , Rentsch Doris
Published: July 2024

The four-carbon non-proteinogenic amino acid γ-aminobutyric acid (GABA) accumulates to high levels in plants in response to various abiotic and biotic stress stimuli, and plays a role in C:N balance, signaling, and as a transport regulator. Expression in Xenopus oocytes and voltage-clamping allowed the characterization of Arabidopsis GAT2 (At5g41800) as a low affinity GABA transporter with a K0.5GABA ~8 mM. l-Alanine and butylamine represented additional substrates. GABA-induced currents were strongly dependent on the membrane potential, reaching the highest affinity and highest transport rates at strongly negative membrane potentials. Mutation of Ser17, previously reported to be phosphorylated in planta, did not result in altered affinity. In a short-term stress experiment, AtGAT2 mRNA levels were up-regulated at low water potential and under osmotic stress (polyethylene glycol and mannitol). Furthermore, AtGAT2 promoter activity was detected in vascular tissues, maturating pollen, and the phloem unloading region of young seeds. Even though this suggested a role for AtGAT2 in long-distance transport and loading of sink organs, under the conditions tested neither AtGAT2-overexpressing plants, atgat2 or atgat1 T-DNA insertion lines, nor atgat1 atgat2 doubleknockout mutants differed from wild-type plants in growth on GABA, amino acid levels, or resistance to salt and osmotic stress.
High-Frequency Oscillations
Authors: Menendez de la Prida Liset , Gotman Jean
Published: July 2024

This chapter focuses on high frequency oscillations (HFOs), which are also known as transient oscillations in the broad 80 to 6000 Hz frequency range. HFOs typically represent a normal physiological activity and pathological phenomenon found in epileptic tissue. Technologies like intracranial EEG (iEEG) and scalp electrodes aid with recording HFOs and ripples that became an important biomarker of epilepsy and epileptogenesis. The chapter highlights the significance of identifying ripples and fast ripples of neuronal activity, which are neurophysiological events that can be defined by features such as association with sharp waves and particular laminar distribution. It then expounds on the differences between physiological HFOs and pathological HFOs.
Seizures and Sleep
Authors: Frauscher Birgit , Timofeev Igor
Published: July 2024

This chapter highlights recent advances in our understanding of the bidirectional interactions between sleep and epilepsy. It describes underlying neuronal correlates of sleep oscillations and epileptic activity followed by an overview of how epileptic activity during the interictal and ictal state relates to sleep. It highlights effects of sleep microstructure and sleep stability on epileptic activity, with slow oscillations and sleep fragmentation enhancing epileptic activity, and phasic rapid-eye-movement sleep having suppressive properties. Moreover, it discusses evidence of the contribution of sleep studies for improved identification of the epileptogenic zone and prediction of seizure outcome. In addition to the effects of sleep, this chapter explains how epileptic activity is influenced by longer time intervals on a day, multiday, and year scale. It then discusses how the link between epileptic activity and sleep microstructure might affect physiological functioning beyond seizures by impairing the fine-tuned orchestration of slow oscillations, spindles, and ripples necessary for memory consolidation, and reviews research addressing this question in epilepsy. Finally, the chapter provides an overview of the relationship between sudden unexplained death in epilepsy, sleep, and seizures, and discusses cardio-respiratory dysfunction as one putative mechanism. The review concludes with discussing future directions necessary to bridge current gaps in understanding, and it provides suggestions for advancing this field.
Human Single-Neuron Recordings in Epilepsy
Authors: Merricks Edward M. , Schevon Catherine A.
Published: July 2024

This chapter reviews the history, technology, and scientific contributions of single-neuron recordings in humans, which have largely been conducted in epilepsy patients undergoing surgical procedures for clinical treatment purposes. Single-neuron recordings have been used by epileptologists to study interictal discharges and the onset, propagation, and termination of human focal seizures, and by neuroscientists and biomedical engineers to study normal cognition in areas such as visual and spatial memory and decision-making. While there are many practical and ethical limitations, this work has proven invaluable for both exploratory studies and for validating research from animal or computational models. Ongoing technological innovation is likely to expand the use and applicability of human single-neuron studies in the foreseeable future.
Convergence of Thalamic Mechanisms in Genetic Epilepsies
Authors: Cho Frances S. , Paz Jeanne T.
Published: July 2024

The thalamus, a deep brain structure with broad connectivity, plays key roles in local and global rhythmic activity in sleep, arousal, and cognition. Disruptions in thalamic and thalamocortical circuits—and the ensuing hypersynchrony and hyperexcitability—have been widely studied in the context of genetic epilepsies and have garnered increasing interest in the context of acquired epilepsies. In this chapter, key structural, synaptic, cellular, and biophysical elements underlying the rhythmogenic properties of the thalamus are described, and then how diverse perturbations of these properties in rodent genetic models ultimately generate or facilitate seizures. The chapter briefly highlights recent studies which have identified mechanisms of thalamic involvement in the development or modulation of epilepsies acquired following incidents such as traumatic brain injury and ischemic stroke. Understanding how diverse etiologies converge upon thalamic hyperexcitability can pinpoint elements of vulnerability, resilience, redundancy, necessity, and sufficiency in the thalamocortical circuit. Understanding how the thalamus generates and modulates aberrant activity—even when it is not the primary or sole site of genetic perturbation—will be key to identifying therapeutic targets and paradigms to treat epilepsies. Such efforts will benefit from continued advancements in our knowledge of cell-type heterogeneity, meso- and macro-scale connectivity, and interspecies differences in the thalamus.
The Diverse Roles of Mossy Cells in the Normal Brain, Epileptogenesis, and Chronic Epilepsy
Authors: Scharfman Helen E.
Published: July 2024

Mossy cells (MCs) of the dentate gyrus (DG) are glutamatergic neurons with the potential for different roles in the normal brain. In epilepsy, particularly temporal lobe epilepsy (TLE), MCs are also considered to be important based on their vulnerability to the brain insults that can cause TLE. Two hypotheses have developed to explain the effects of MC loss in TLE: the dormant basket cell hypothesis suggest that MC death weakens GC inhibition, promoting seizures. The second hypothesis, the irritable mossy cell hypothesis, suggests that those MCs that survive in TLE increase GC excitation. This chapter discusses a “bridging hypothesis” based on the idea that MC functions change depending on the state of the DG network: the normal state, the state during the initial insult of TLE, or during chronic epilepsy in TLE. It is suggested that during the normal state MCs mainly inhibit GCs by activating DG GABAergic neurons. In contrast, during the initial insult, MCs excitation of GCs increases dramatically. After the insult, many of the MCs and hilar GABAergic neurons die due to excitotoxicity. However, some survive, and in chronic epilepsy there are significant structural and functional changes to the circuitry. MCs appear to revert to their mainly inhibitory role. This view reconciles data showing that inhibition of MCs during the initial insult will decrease excitotoxicity, reducing epileptogenesis, but activation of MCs in chronic epilepsy will reduce convulsive seizures. In summary, it is suggested that MCs have diverse roles in the DG that greatly influence the GCs and are different depending on the state of the network.
Temporal Lobe Epileptogenesis
Authors: Sloviter Robert S.
Published: July 2024

In families with febrile seizures and temporal lobe epilepsy, mutations affecting different GABAergic mechanisms suggest that failure of chloride conductance to limit depolarization may be directly epileptogenic. This “GABAergic disinhibition” hypothesis has been discounted historically for two reasons. First, early attempts to produce hippocampal sclerosis and epilepsy simply by eliminating hippocampal GABA neurons consistently failed to do so. Second, the notion persists that because clinical epilepsy diagnosis is typically delayed for years or decades after brain injury, temporal lobe epileptogenesis should be presumed to involve a complex pathological transformation process that reaches completion during this “latent period.” Recent advances clarify both issues. Although spatially limited hippocampal GABA neuron ablation causes only submaximal granule cell hyperexcitability, more spatially extensive ablation maximizes granule cell hyperexcitability and triggers nonconvulsive granule cell status epilepticus, hippocampal sclerosis, and epilepsy. Recent studies also show that disinhibited granule cells begin to generate clinically subtle seizures immediately post-injury, and these seizures then gradually increase in duration to become clinically obvious. Therefore, rather than being a seizure-free “gestational” state of potentially interruptible epileptogenesis, the “latent period” is more likely an active epileptic state when barriers to seizure spread and clinical expression are gradually overcome by a kindling process. The likelihood that an epileptic brain state exists long before clinical diagnosis has significant implications for anti-epileptogenesis studies. The location, magnitude, and spatial extent of inherited, autoimmune, and injury-induced disinhibition may determine the latency to clinical diagnosis and establish the continuum between the benign, treatable, and refractory forms of temporal lobe epilepsy.
Neuroinflammation in Epilepsy
Authors: Dingledine Ray , Varvel Nicholas H. , Ravizza Teresa , Vezzani Annamaria
Published: July 2024

Neuroinflammation and epilepsy appear to exist in a self-reinforcing circular arrangement, whereby inflammatory pathways lower seizure threshold and the ensuing seizures trigger neuroinflammation. This forms the essential logic of anti-inflammatory therapies, which seek to interrupt the vicious cycle or to prevent it. Many if not all neuroinflammatory mediators are known to play physiological roles in the healthy brain, for example, regulation of astroglial potassium buffering by TGFβ, and the strength of excitatory synaptic transmission by PGE2 and IL-1β ανδ TNΦ. These neuromodulatory roles are usurped in epilepsy, when the neuroinflammatory mediators are transformed from their physiologic functions to agents of havoc as their local concentration rises or they persist too long in brain tissue. This chapter focuses on IL-1β, TNF, IL-6, PGE2, CXCL1, CCL2, and drivers of the complement pathway, which have all received substantial attention over the past decade. This chapter describes these inflammatory mediators and discusses how they may create a pathological milieu permissive for seizures, cell loss, and behavioral dysfunctions.
Role of Reactive Oxygen Species in Epilepsy
Authors: Hari Ashwini Sri , Walker Matthew C. , Patel Manisha
Published: July 2024

Since the last edition of this volume, there have been major advances in our understanding of redox mechanisms in epilepsies. The brain’s architecture, cell types, and function make it uniquely susceptible to oxidative damage. Animal models of acquired epilepsy have revealed reactive oxygen species generated by multiple cellular sources; oxidant damage to cellular lipids, proteins, and deoxyribonucleic acid; and an altered thiol redox status. Preclinical studies have identified several redox-based therapeutic strategies to improve epilepsy and/or its comorbidities. This chapter provides an overview of the role of redox dysregulation in epilepsy with emphasis on therapeutic targets.
Transcriptomic Alterations in Epileptogenesis
Authors: Brennan Gary P. , van Loo Karen M. J.
Published: July 2024

Epilepsy is associated with many transcriptomic alterations. In recent years, considerable progress has been made in the identification of epilepsy-associated genes, but we have only begun to understand the underlying mechanisms of epilepsy-driven transcriptional dysregulation. This chapter reviews the state of the current knowledge regarding the transcriptional mechanisms in experimental and human epilepsy and focuses on transcription factor–mediated dysregulation. The chapter describes how the expression of epilepsy-associated genes is affected, and it discusses the possible functional consequences of these alterations in the different phases of epileptogenesis.
Blood Biomarkers
Authors: Henshall David C. , Simonato Michele
Published: July 2024

The diagnosis of epilepsy and recent seizure remain important clinical challenges. Blood-based molecules represent potential circulating biomarkers that could provide simple, cheap, quick tests to support diagnosis, prognosis, monitoring, and decisions on choice and effectiveness of therapy. There have been recent and significant advances in identifying candidate molecules. A number of proteins hold promise, including HMGB1, matrix proteins, and neuron-enriched markers such as UCHL1. Small noncoding RNAs called microRNAs have more recently emerged, with interest stemming from their tissue-specific expression, suitability for rapid and quantitative assay, and link to mechanisms of disease and potential as treatments. Here we review why blood-based biomarkers are needed, the properties sought, and the quality and quantity of evidence obtained from clinical and experimental studies. We finish by identifying the necessary studies in the future that could bring these valuable supports to the clinic.
Sodium Channelopathies in Human and Animal Models of Epilepsy and Neurodevelopmental Disorders
Authors: Yamakawa Kazuhiro , Meisler Miriam H. , Isom Lori L.
Published: July 2024

The genes SCN1A, SCN2A, and SCN8A encode the voltage-gated sodium channel (VGSC) α-subunits Nav1.1, Nav1.2, and Nav1.6, respectively. Dravet syndrome is eat the severe end of the disease spectrum caused by SCN1A variants, and Nav1.1 haploinsufficiency in parvalbumin-positive inhibitory neurons has been proposed as a primary cause for the disease. Nav1.2 is predominantly expressed in excitatory neurons in neocortex and hippocampus. SCN2A is the gene with the largest number of de novo variants in patients with autism spectrum disorder and/or intellectual disability, and those are mainly truncations. SCN2A variants also appear in patients with epileptic encephalopathies, but those are mostly missense. Variants of SCN8A have been reported in a number of patients with variable epilepsies. Gain-of-function missense variants are the most common in SCN8A developmental and epileptic encephalopathy associated with motor manifestations such as ataxia and choreoathetosis in the most severe cases. SCN1B encodes the non-pore-forming VGSCβ1 and β1B subunits, which are multifunctional channel regulatory molecules expressed in excitatory and inhibitory neurons. SCN1B variants are reported in patients with epilepsies of multiple etiologies. In vitro and animal model studies have provided critical insights into pathological mechanisms of the diseases caused by genetic variation in these genes.
Transcriptional Regulation of Cortical Interneuron Development
Authors: Pai Emily Ling-Lin , Vogt Daniel , Hu Jia Sheng , Rubenstein John L.
Published: July 2024

GABAergic interneurons (INs) constitute 20%–30% of the pallial (neocortical and hippocampal) neurons. They are the main source of cortical and hippocampal synaptic inhibitory signals. Distinct IN subtypes inhibit different cellular and subcellular components of pallial circuits. INs are generated from different subdomains of the embryonic basal ganglia (ganglionic eminences, GEs). Transcription factors (TFs) through regulatory elements (REs) that they bind are integral in programming gene expression in a temporally and spatially diverse manner. This then programs cell fate-commitment, differentiation, migration, and maturation to generate different IN subtypes. Of note, the prevailing molecular and genetic knowledge about IN development has been established by decades of studies in rodent and is hypothesized to reflect many of the processes common to mammals. Research on human and primate brain development will test this hypothesis and also offers the opportunity to identify species-specific variations. In this chapter, we focus on discoveries derived from mouse research. This chapter reviews the histology of the GEs, fate-mapping tools, TFs that control regional patterning of the GEs, TFs that regulate IN maturation, and REs that are involved in IN development.