bluuebunny/crossref_metadata_2025 huggingface dataset:
A novel deep learning algorithm applied to machine vision inspection for surface defects of injection moulded products
Authors: Fan Haipeng , Qiu Zhongjun
Published: January 2024

In modern industry, the surface defect inspection of injection moulded products is crucial for controlling product quality and optimising the manufacturing process. With the development of optical measurement and computer technology, machine vision inspection methods have been widely adopted instead of manual inspection. However, current machine vision inspection methods are difficult to simultaneously ensure the accuracy and efficiency of surface defect inspection of injection moulded products. Considering this problem, a novel deep learning algorithm applied to machine vision inspection for surface defects of injection moulded products is proposed. To train and evaluate the proposed deep learning algorithm, an image acquisition platform is established and the dataset of surface defects in moulded products is obtained. In the proposed deep learning algorithm, reparameterisation-based convolution modules are employed for feature extraction and feature fusion. A median iterative clustering algorithm based on hierarchical clustering initialisation is proposed to obtain prior anchors that are highly matched with the actual distribution of defect sizes. A novel focus-entire union over covering loss function is utilised for bounding box regression. On these bases, the proposed deep learning algorithm applied to machine vision inspection is evaluated on the dataset of surface defects in moulded products. The experimental results indicate that compared to the traditional inspection algorithms and other deep learning algorithms currently used in machine vision inspection, the proposed deep learning algorithm exhibits superior inspection accuracy and inspection efficiency on the acquired dataset. The inspection precision reaches 0.964, the inspection recall reaches 0.955, and the inference time for each subgraph is only 6.1 ms, confirming its effectiveness.
Streamer-induced kinetics of excited states in pure N2: II. Formation of N2(B 3Πg,v=0–21
) through analysis of emission produced by the first positive system
Authors: Bílek Petr , Dias Tiago Cunha , Prukner Václav , Guerra Vasco , Šimek Milan
Published: January 2024

Vibrational distributions of electronically excited states of N2 obtained through dipole-allowed radiative transitions provide an important tool to study the kinetics of non-equilibrium plasmas under various discharge conditions. In this work, we report, for the first time, streamer-induced visible/near-infra-red emission spectra developing during the first hundred nanoseconds after the initiation of the discharge. Emission through the first positive system of N2 was acquired in 500–1100 nm range, which allows a complete analysis of the N2(B

3

Π

g

,
v

= 0–21) vibrational manifold. The investigated evolution of the vibrational distribution of the N2(B

3

Π

g

, v = 0–21) state at the centre of the gap corresponds to the transition of the streamer head and the subsequent decay of the streamer channel. We show that the vibrational distribution characterising streamer head is determined by Franck–Condon factors, while during streamer relaxation, it is influenced by the complex interaction between triplet excited states of N2. Additionally, the observed N2(B

3

Π

g

, v = 13–21) vibrational levels are likely produced by the interaction of high vibrational levels of N2(W

3

Δ

u

, B’

3

Σ

u

−

, B

3

Π

g

)

with

N

2

(

C

3

Π

u

)

state. We also provide a detailed kinetic scheme for modelling vibrationally-resolved N2(B

3

Π

g

) state and compare model results with experimental outcomes.
Experimental tests and numerical simulations of miniature buckling-restrained braces using iron-shape memory alloy bar
Authors: Wang Yuanzuo , Jiang Tianyuan , Qiu Canxing , Zhang Aifang , Liu Jiawang , Du Xiuli
Published: January 2024

Miniature buckling-restrained braces (BRBs) have a concise configuration and clear working mechanism. Owing to stable and full hysteresis, miniature BRBs are emerging as favorable energy-dissipating fuse elements in seismic applications. This paper proposes using iron-shape memory alloy (FeSMA) in lieu of conventional steel as the yielding core and focuses on the cyclic behavior. Four specimens, corresponding to four loading protocols, were fabricated and tested. According to experimental data, the miniature FeSMA BRBs exhibited full hysteresis, which is characterized by large damping, noticeable isotropic and kinematic hardening behavior and appreciable post-yield stiffness ratio. The cumulative plastic deformations meet the requirement by ANSI/AISC 341-16. Further, high fidelity finite element models, which explicitly considered damage and fracture rules, were established for numerical simulations. Good agreement can be found between the experimental data and numerical simulations, in terms of failure modes, fracture locations and global hysteresis.
Investigation of healing electronic pressure-sensitive soft switch based on liquid metal microfiber
Authors: Ren Yijun , Wen Xiaolong , Bian Hairui
Published: January 2024

Flexible and wearable electronics have gained extensive attention in health monitoring, electronic skin, and sensors due to their flexibility, portability, sensitivity, and biocompatibility. Liquid metal (LM) is an optimum conductive material for soft electronic devices because of its high conductivity and fluidity at room temperature. Nevertheless, LM electronic devices with stable dimension is a formidable challenge due to its relatively high surface tension and mass density. In this study, we introduce a wet spinning approach that utilises sodium alginate as the exterior phase and LM as the interior phase. Calcium lactate is used to solidify the sodium alginate, thereby producing liquid metal microfibers (LMMs). The LMMs can be modified by adjusting the flow rate of the two-phase materials. The encapsulated LM microcapsule can serve as a healing electronic soft switch that is suitable for use in wearable and flexible electronic devices. Initially, the liquid metal soft switch (LMSS) has a high resistance value. Once a specific amount of pressure is applied, the resistance value drops considerably resulting in the switch’s activation. And LMMs coated by the sodium alginate can dissolve in a trisodium citrate solution, so that the LM can be reshaped under mixed each other. It achieves LMSS’s reusability and recycling.
Design and integration of textile-based temperature sensors for smart textile applications
Authors: Rasheed Abher , Imran Aqsa , Abrar Amna , Zaman Shahood uz
Published: January 2024

Wearable technology is now frequently utilized to check people’s health. Body temperature measurements needed for telemedicine and real-time health monitoring applications can be taken with wearable temperature sensors. The goal of this work was to create thermocouples made of textiles for use in smart textile applications, particularly temperature monitoring in outfield uniforms. The thermocouples were created using metal wire and conductive yarns; however, metal-based thermocouples were only created for reference. In these studies, three junction levels and three distinct materials were used, and the Seebeck coefficient for these samples was examined. A four-probe heating system coupled with a multimeter was used to calculate the Seebeck coef-ficient. Results show that the cotton-based conductive yarn thermo-couple with stainless steel yarn (C + SS2) junction performed well with the best Seebeck coefficient value. The thermocouple values with one, five, and ten junctions were sequentially 167.56 µv °C−1, 227.30 µv °C−1, and 267.54 µv °C−1. After the integration, ten junction thermocouples of C + SS2 showed the best Seebeck coefficient values.
Breaking reflection symmetry: evolving long dynamical cycles in Boolean systems
Authors: Ouellet Mathieu , Kim Jason Z , Guillaume Harmange , Shaffer Sydney M , Bassett Lee C , Bassett Dani S
Published: January 2024

In interacting dynamical systems, specific local interaction rules for system components give rise to diverse and complex global dynamics. Long dynamical cycles are a key feature of many natural interacting systems, especially in biology. Examples of dynamical cycles range from circadian rhythms regulating sleep to cell cycles regulating reproductive behavior. Despite the crucial role of cycles in nature, the properties of network structure that give rise to cycles still need to be better understood. Here, we use a Boolean interaction network model to study the relationships between network structure and cyclic dynamics. We identify particular structural motifs that support cycles, and other motifs that suppress them. More generally, we show that the presence of dynamical reflection symmetry in the interaction network enhances cyclic behavior. In simulating an artificial evolutionary process, we find that motifs that break reflection symmetry are discarded. We further show that dynamical reflection symmetries are over-represented in Boolean models of natural biological systems. Altogether, our results demonstrate a link between symmetry and functionality for interacting dynamical systems, and they provide evidence for symmetry’s causal role in evolving dynamical functionality.
Large-scale geometry of the Universe
Authors: Awwad Yassir , Prokopec Tomislav
Published: January 2024

The large scale geometry of the late Universe can be decomposed
as ℝ × Σ3, where ℝ
stands for cosmic time and Σ3 is the three dimensional
spatial manifold.
We conjecture that the geometry of the Universe's spatial
section Σ3
conforms with the Thurston-Perelman theorem,
according to which the geometry of Σ3 is either one of the
eight geometries from the Thurston geometrization conjecture,
or a combination of Thurston geometries smoothly sewn together.
We assume that topology of individual geometries plays
no observational role, i.e. the size of individual
geometries is much larger than the Hubble radius today.
We investigate the dynamics of each of the individual
geometries by making use of the simplifying assumption
that our local Hubble patch consists of only one such geometry,
which is approximately homogeneous on very large scales,
but spatial isotropy is generally violated.

Spatial anisotropies grow in time in decelerating universes, but they
decay in accelerating universes. The thus-created anisotropy problem can be solved
by a period of primordial inflation, akin to how the flatness problem is solved.
Therefore, as regards Universe's large scale geometry,
any of the Thurston's geometries should be considered on a par with
Friedmann's geometries.

We consider two observational methods that can be used to test our conjecture: one based on
luminosity distance and one on angular diameter
distance measurements,
but leave for the future their detailed forecasting implementations.
A new strategy for the determination of dinobuton fungicide by square wave stripping voltammetry on the multi-walled carbon nanotube electrode
Authors: Murathan Zeynep , İnam Recai , Demir Ersin
Published: January 2024

Dinobuton is a fungicide with a dinitrophenol group pesticide, and its electrochemical behavior was investigated by cyclic voltammetry (CV) and square wave stripping voltammetry (SWSV) on a multi-walled carbon nanotube paste electrode (MWCNTPE). First of all, optimum parameters such as pH, step potential, frequency, puls amplitude, deposition time and, deposition potential were specified by using SWSV on the MWCNTPE. In the negative potential scans, two cathodic peaks appeared at nearly −480 mV and –760 mV due to the nitro groups on the molecule and the second sharp one appeared at −760 mV (versus Ag/AgCl) was used for analytical purposes. The linear working range was found to be within 3.74–25.8 μM on the MWCNTPE by SWSV in pH 7.0 Britton Robinson (BR) buffer solution. The limit of detection (LOD) and limit of quantification (LOQ) values were found to be 0.73 μM and 2.43 μM, respectively. The interference study was conducted in the presence of some pesticides such as triasulfuron, azinphos-methyl, bromoxynil-octanoate, dialifos, fipronil, vinclozolin, iprodione, procymidone, and some selected metal ions withal. Furthermore, the proposed method was also applied to apple juice, tap water, and grape juice, and percent recoveries (%) were detected as 105.9 ± 4.3; 98.3 ± 0.9; 103.7 ± 2.5% with relative standard deviations of 4.0, 1.0, and 2.4%, respectively. On the other hand, percent relative errors were calculated as 5.90, 1.65, and 3.74%, respectively. High recoveries and low relative standard deviations indicate that the applicability of the proposed method in both matrix and real samples is satisfying.
Temperature and strain characteristics of ceramic-reinforced polyurethane insulation decorative board under artificial accelerated aging conditions
Authors: Ma Tengfei , Yuan Kelong , Xiong Houren , sha Bin , Zhong Qinfang , Sun Linxiao
Published: January 2024

As a new type of thermal insulation material, ceramic-reinforced polyurethane insulation decorative board (IDB) has been applied to a certain extent, but changes in the temperature and strain between this material and the substrate wall during the aging process remain unclear. In this study, an external insulation composite system with ceramic-reinforced polyurethane IDB was subjected to 60 heat-rain cycles, and the temperature and strain at the interface between the IDB and the substrate wall were measured. The results show that the temperature of the substrate wall is about 35 °C lower than the highest temperature of the environmental box, and the temperature fluctuation of the substrate wall during 60 heat-rain cycles always maintains at about 5 °C, which indicates that the ceramic reinforced polyurethane IDB has good thermal insulation performance and durability. During the heat-rain cycles, the vertical strain varies from −750 με to + 2750 με, while the horizontal strain varies from −250 με to + 500 με, indicating that the horizontal and vertical strains have serious inhomogeneity. This local inhomogeneity may be an important reason for the aging and cracking of the IDB. The characteristics of temperature and strain could provide a reference for analyzing the synergistic effect and disbonding mechanism of the interface between the IDB and the substrate wall, and give some guidance for the design and construction of external insulation composite systems.
Upcycling waste tilapia (oreochromis niloticus) scales through a decellularization process for extracellular matrix extraction
Authors: Arellano Fernan M , Bual Ronald , Bantilan Zesreal Cain , Alimasag Johnel , Aron Jemwel , Baclayon Lean , Nisperos Michael John , Valle Kit Dominick Don , Ducao Princess Grace , Lumancas Gladine , Pague Job Jr , Labares Marionilo Jr , Bacosa Hernando
Published: January 2024

Tilapia scales, typically regarded as low-value biological waste, possess valuable organic components such as collagen and inorganic components such as hydroxyapatite. Converting these wastes into functional biomaterials like decellularized extracellular matrix (dECM) contributes to long-term fish waste management to achieve sustainable fish consumption and promote a circular economy by creating a product with a high market value. Triton X-100 (TX-100) and Sodium-dodecyl sulfate (SDS) at varying concentrations (0.1%, 0.5%, and 1%) are utilized to extract the extracellular matrix. The study aims to evaluate the effectiveness of these agents in decellularizing the scales and producing a suitable dECM scaffold. Histological analysis using H&E staining revealed a significant decrease in cellular components in the decellularized samples. This was supported by the dsDNA quantification results showing the highest removal rate of 96% in the samples treated with 1% SDS. Attenuated Total Reflectance-Fourier-transform infrared (ATR-FTIR) spectra showed the amide peaks (Amide A, B, I, II, and III) indicating the presence of type I collagen. The confirmation of type I collagen was further supported by the analysis of SDS-PAGE images, which displayed the presence of α1 and α2 chains, β-dimer, and the γ-band. Among the dECM, samples treated with 0.1% TX-100 exhibited the highest protein content, averaging 593.33 ± 17.78 μg mg−1 while 1% SDS showed the lowest protein content averaging 61.33 ± 24.03μg mg−1. All dECM samples demonstrated protein denaturation temperatures ranging from 70–75 °C. This study presents baseline data of the single chemical decellularization treatment method utilized to extract ECM from tilapia scales and its resulting dECM. Further research is recommended to assess the biocompatibility and cytotoxicity of the produced dECM and explore its potential applications.
Benchmarking the ragone behaviour and power performance trends of pseudocapacitive batteries
Authors: Foong Yee Wei , Bevan Kirk H
Published: January 2024

The ‘holy grail’ of energy storage is to achieve both high energy and high power densities (

⩾
100

Wh l−1 and

∼

10
4

W l−1, respectively) as characterized in a Ragone plot. However, across the macroscopic dimensions over which energy storage systems operate, power performance is fundamentally limited by both drift and diffusion processes. In this work a macroscopic variation on the Gerischer–Hopfield formalism is applied to explore how the motion of electrical charges, moving between redox species, and screening counter-ions might be engineered in a pseudocapacitive system employing quantized capacitance (in the form of a pseudocapacitive battery) to reach this long-sought metric. Our theoretical findings show that the electron diffusion timescale between redox species generally determines power performance trends when pseudocapacitive coatings are applied monolithically. This electron-diffusion–dominated timescale, in turn, is shown to scale with the square of the coating thickness. However, when conducting pathways (or shunts) are introduced to substantially reduce the mean distance for electron diffusion the Ragone performance becomes dominated by ion drift and diffusion—even when the diffusion constants of all species are held equal. The resulting trends, for this shunting regime, show a power performance timescale that scales in a more linear fashion with increasing thickness of the redox-active region. By analyzing the Ragone performance metrics for realistic coating thicknesses between these two operational regimes, the resulting findings suggest that the diffusion constants needed to achieve the aforementioned high-performance metrics are plausibly achievable for both electronic and ionic charges in this proposed class of pseudocapacitive systems.
Numerical search for time-of-flight focusing conditions and its application to the analysis of TOF mass analyzer schemes
Authors: Kambarova Zhanar , Saulebekov Arman , Trubitsyn Andrey
Published: January 2024

A method of searching for high-order time-of-flight focusing conditions based on data of numerical trajectory analysis of corpuscular-optical systems is presented. The method makes it possible to determine the maximum achievable order of focusing, the value of the independent variable (initial coordinate, initial angle, initial velocity or energy) relative to which the focusing is observed, as well as the spatial position of focus. The method has been tested on model problems. The corpuscular-optical properties of time-of-flight devices with known analytical solutions are investigated, and the uniqueness of their parameters in their class is shown.
Optimizing collective behavior of communicating active particles with machine learning
Authors: Grauer Jens , Jan Schwarzendahl Fabian , Löwen Hartmut , Liebchen Benno
Published: January 2024

Bacteria and other self-propelling microorganisms produce and respond to signaling molecules to communicate with each other (quorum sensing) and to direct their collective behavior. Here, we explore agents (active particles) which communicate with each other to coordinate their collective dynamics for maximizing nutrient consumption. Using reinforcement learning and neural networks, we identify three different strategies: a ‘clustering strategy’, where the agents accumulate in regions of high nutrient concentration; a ‘spreading strategy’, where particles stay away from each other to avoid competing for sparse resources; and an ‘adaptive strategy’, where the agents adaptively decide to either follow or stay away from others. Our work exemplifies the idea that machine learning can be used to determine parameters that are evolutionarily optimized in biological systems but often occur as unknown parameters in mathematical models describing their dynamics.
Limited reversal of regional climate signals in overshoot scenarios
Authors: Pfleiderer Peter , Schleussner Carl-Friedrich , Sillmann Jana
Published: January 2024

Without stringent reductions in emission of greenhouse gases in the coming years, an exceedance of the 1.5 °C temperature limit is increasingly likely. This has given rise to so-called temperature overshoot scenarios, in which the global mean surface air temperature exceeds a certain limit (i.e. 1.5 °C above pre-industrial levels) before bringing temperatures back below that limit. Despite their prominence in the climate mitigation literature, the implications of an overshoot for local climate impacts is still understudied. Here we present a comprehensive analysis of implications of an overshoot for regional temperature and precipitation changes as well as climate extremes indices. Based on a multi-model comparison from the Coupled Model Intercomparison Project we find that temperature changes are largely reversible in many regions, but also report significant land–ocean and latitudinal differences after an overshoot. For precipitation, the emerging picture is less clear. In many regions the drying or wetting trend is continued throughout the overshoot irrespective of a change in the global mean temperature trend with resulting consequences for extreme precipitation. Taken together, our results indicate that even under a reversal of global mean temperature increase, regional climate changes may only be partially reversed in the decades after peak warming. We thus provide further evidence that overshooting of a warming level implies considerable risks on the regional level.
Carbon dioxide as an indicator of bioaerosol activity and human health in K-12 school systems: a scoping review of current knowledge
Authors: Gangwar Mayank , Jamal Yusuf , Usmani Moiz , Wu Chang-Yu , Jutla Antarpreet S
Published: January 2024

Indoor air quality (IAQ) in schools has received attention over the past decades but still lacks specific standards and regulations. This study aimed to review the impact of bioaerosol activity in indoor environments on acute respiratory diseases and explore whether carbon dioxide can be used as an indicator of bioaerosol and respiratory diseases in indoor environments in K-12 school systems. Findings suggest a lack of a consensual approach to evaluate bioaerosols impacting IAQ in indoor infrastructures, particularly in school environments; an elevated CO2 concentration inside the school classrooms was not uncommon, and the evidence of unsatisfactory and degraded IAQ (surpassing ASHRAE standards) at public schools in rural and urban settings in one of the North Central County, Florida. It was found that CO2 levels can be associated with bioaerosol activity, and sufficient ventilation within the space substantially reduces the airborne time of respiratory droplets and CO2 levels. CO2 monitoring can act as an effective, low-cost alternative to surveying or detecting the prevalence of respiratory diseases, which may hold strength through establishing critical CO2 thresholds and, thereafter associating it with the infectious doses of pathogen activity.
Logic in the deep end
Authors: Leach-Krouse Graham , Allen Logan Shay , Worley Blane
Published: January 2024

Weak enough relevant logics are often closed under depth substitutions. To determine the breadth of logics with this feature, we show there is a largest sublogic of R closed under depth substitutions and that this logic can be recursively axiomatized.
PfPIN5 promotes style elongation by regulating cell length in Primula forbesii Franch
Authors: Liu Ying , Si Weijia , Fu Sitong , Wang Jia , Cheng Tangren , Zhang Qixiang , Pan Huitang
Published: January 2024

Background and Aims

Style dimorphism is one of the polymorphic characteristics of flowers in heterostylous plants, which have two types of flowers: the pin morph, with long styles and shorter anthers, and the thrum morph, with short styles and longer anthers. The formation of dimorphic styles has received attention in the plant world. Previous studies showed that CYP734A50 in Primula determined style length and limited style elongation and that the brassinosteroid metabolic pathway was involved in regulation of style length. However, it is unknown whether there are other factors affecting the style length of Primula.

Methods

Differentially expressed genes highly expressed in pin morph styles were screened based on Primula forbesii transcriptome data. Virus-induced gene silencing was used to silence these genes, and the style length and anatomical changes were observed 20 days after injection.

Key Results

PfPIN5 was highly expressed in pin morph styles. When PfPIN5 was silenced, the style length was shortened in pin and long-homostyle plants by shortening the length of style cells. Moreover, silencing CYP734A50 in thrum morph plants increased the expression level of PfPIN5 significantly, and the style length increased. The results indicated that PfPIN5, an auxin efflux transporter gene, contributed to regulation of style elongation in P. forbesii.

Conclusions

The results implied that the auxin pathway might also be involved in the formation of styles of P. forbesii, providing a new pathway for elucidating the molecular mechanism of style elongation in P. forbesii.
Role of inter-alpha-trypsin inhibitor heavy chain 4 and its citrullinated form in experimental arthritis murine models
Authors: Iwai Tamaki , Ohyama Ayako , Osada Atsumu , Nishiyama Taihei , Shimizu Masaru , Miki Haruka , Asashima Hiromitsu , Kondo Yuya , Tsuboi Hiroto , Mizuno Seiya , Takahashi Satoru , Ishigami Akihito , Matsumoto Isao
Published: January 2024

Inter-α-trypsin inhibitor heavy chain 4 (ITIH4) is a major protein in serum and reported to be upregulated at the onset of rheumatoid arthritis (RA). Its citrullinated form, cit-ITIH4, is specifically found in the serum and synovial fluid of patients with RA. However, the detailed function of ITIH4 in arthritis remains unknown. The aim of this study was to clarify the role of ITIH4 and cit-ITIH4 using experimental arthritis models. ITIH4 and cit-ITIH4 expression was examined in steady-state mice and two different arthritis models, and their pathological effects were examined in Itih4-deficient mice. In naïve C57BL/6 (WT) mice, ITIH4 was expressed as mRNA in the liver and the lung and was expressed as protein in serum and hepatocytes. In K/BxN serum transferred arthritis (K/BxN-STA) and collagen-induced arthritis (CIA), ITIH4 and cit-ITIH4 in sera were increased before the onset of arthritis, and cit-ITIH4 was further increased at the peak of arthritis. In Itih4-deficient mice, citrullinated proteins in serum and joints, especially 120 kDa protein, were clearly diminished; however, there was no significant difference in arthritis severity between WT and itih−/− mice either in the K/BxN-STA or CIA model. CIA mice also exhibited pulmonary lesions and itih4−/− mice tended to show enhanced inflammatory cell aggregation compared to WT mice. Neutrophils in the lungs of itih4−/− mice were significantly increased compared to WT mice. In summary, ITIH4 itself did not alter the severity of arthritis but may inhibit autoimmune inflammation via suppression of neutrophil recruitment.
Memory consolidation of sequence learning and dynamic adaptation during wakefulness
Authors: Wang Yiyu , Huynh Angelina T , Bao Shancheng , Buchanan John J , Wright David L , Lei Yuming
Published: January 2024

Motor learning involves acquiring new movement sequences and adapting motor commands to novel conditions. Labile motor memories, acquired through sequence learning and dynamic adaptation, undergo a consolidation process during wakefulness after initial training. This process stabilizes the new memories, leading to long-term memory formation. However, it remains unclear if the consolidation processes underlying sequence learning and dynamic adaptation are independent and if distinct neural regions underpin memory consolidation associated with sequence learning and dynamic adaptation. Here, we first demonstrated that the initially labile memories formed during sequence learning and dynamic adaptation were stabilized against interference through time-dependent consolidation processes occurring during wakefulness. Furthermore, we found that sequence learning memory was not disrupted when immediately followed by dynamic adaptation and vice versa, indicating distinct mechanisms for sequence learning and dynamic adaptation consolidation. Finally, by applying patterned transcranial magnetic stimulation to selectively disrupt the activity in the primary motor (M1) or sensory (S1) cortices immediately after sequence learning or dynamic adaptation, we found that sequence learning consolidation depended on M1 but not S1, while dynamic adaptation consolidation relied on S1 but not M1. For the first time in a single experimental framework, this study revealed distinct neural underpinnings for sequence learning and dynamic adaptation consolidation during wakefulness, with significant implications for motor skill enhancement and rehabilitation.
Neural response properties predict perceived contents and locations elicited by intracranial electrical stimulation of human auditory cortex
Authors: Wang Qian , Luo Lu , Xu Na , Wang Jing , Yang Ruolin , Chen Guanpeng , Ren Jie , Luan Guoming , Fang Fang
Published: January 2024

Intracranial electrical stimulation (iES) of auditory cortex can elicit sound experiences with a variety of perceived contents (hallucination or illusion) and locations (contralateral or bilateral side), independent of actual acoustic inputs. However, the neural mechanisms underlying this elicitation heterogeneity remain undiscovered. Here, we collected subjective reports following iES at 3062 intracranial sites in 28 patients (both sexes) and identified 113 auditory cortical sites with iES-elicited sound experiences. We then decomposed the sound-induced intracranial electroencephalogram (iEEG) signals recorded from all 113 sites into time-frequency features. We found that the iES-elicited perceived contents can be predicted by the early high-γ features extracted from sound-induced iEEG. In contrast, the perceived locations elicited by stimulating hallucination sites and illusion sites are determined by the late high-γ and long-lasting α features, respectively. Our study unveils the crucial neural signatures of iES-elicited sound experiences in human and presents a new strategy to hearing restoration for individuals suffering from deafness.
Representation of event and object concepts in ventral anterior temporal lobe and angular gyrus
Authors: Zhang Yueyang , Wu Wei , Mirman Daniel , Hoffman Paul
Published: January 2024

Semantic knowledge includes understanding of objects and their features and also understanding of the characteristics of events. The hub-and-spoke theory holds that these conceptual representations rely on multiple information sources that are integrated in a central hub in the ventral anterior temporal lobes. The dual-hub theory expands this framework with the claim that the ventral anterior temporal lobe hub is specialized for object representation, while a second hub in angular gyrus is specialized for event representation. To test these ideas, we used representational similarity analysis, univariate and psychophysiological interaction analyses of fMRI data collected while participants processed object and event concepts (e.g. “an apple,” “a wedding”) presented as images and written words. Representational similarity analysis showed that angular gyrus encoded event concept similarity more than object similarity, although the left angular gyrus also encoded object similarity. Bilateral ventral anterior temporal lobes encoded both object and event concept structure, and left ventral anterior temporal lobe exhibited stronger coding for events. Psychophysiological interaction analysis revealed greater connectivity between left ventral anterior temporal lobe and right pMTG, and between right angular gyrus and bilateral ITG and middle occipital gyrus, for event concepts compared to object concepts. These findings support the specialization of angular gyrus for event semantics, though with some involvement in object coding, but do not support ventral anterior temporal lobe specialization for object concepts.
GABAergic inhibition shapes behavior and neural dynamics in human visual working memory
Authors: Kujala Jan , Ciumas Carolina , Jung Julien , Bouvard Sandrine , Lecaignard Françoise , Lothe Amélie , Bouet Romain , Ryvlin Philippe , Jerbi Karim
Published: January 2024

Neuronal inhibition, primarily mediated by GABAergic neurotransmission, is crucial for brain development and healthy cognition. Gamma-aminobutyric acid concentration levels in sensory areas have been shown to correlate with hemodynamic and oscillatory neuronal responses. How these measures relate to one another during working memory, a higher-order cognitive process, is still poorly understood. We address this gap by collecting magnetoencephalography, functional magnetic resonance imaging, and Flumazenil positron emission tomography data within the same subject cohort using an n-back working-memory paradigm. By probing the relationship between GABAA receptor distribution, neural oscillations, and Blood Oxygen Level Dependent (BOLD) modulations, we found that GABAA receptor density in higher-order cortical areas predicted the reaction times on the working-memory task and correlated positively with the peak frequency of gamma power modulations and negatively with BOLD amplitude. These findings support and extend theories linking gamma oscillations and hemodynamic responses to gamma-aminobutyric acid neurotransmission and to the excitation-inhibition balance and cognitive performance in humans. Considering the small sample size of the study, future studies should test whether these findings also hold for other, larger cohorts as well as to examine in detail how the GABAergic system and neural fluctuations jointly support working-memory task performance.
Single dominant right coronary artery with hypoplastic left coronary branch: a rare congenital anomaly: a case report
Authors: Hamidani Fadhel , Berisha Blerim
Published: January 2024

Background

A right single coronary artery (SCA) and hypoplastic coronary disease represent a rare coronary artery anomaly, which is associated with sudden cardiac death. The clinical manifestations of these anomalies depend on the distribution of collateral vessels.

Case summary

A 55-year-old female presented with dyspnoea, mild chest pain during physical activity, and palpitations. Selective coronary angiography revealed a prominent SCA originating from the right coronary sinus. Approximately 2 mm from the ostium, this artery branched into two: a dominant right coronary artery (RCA) and a smaller artery for the anterior wall perfusion. The dominant RCA then moved posteriorly, bifurcating into a posterior descending artery and a posterolateral artery. The latter occupied the expected location of the left circumflex artery and supplied the majority of the coronary circulation, including the left ventricle. Notably, there were no significant atherosclerotic calcifications or stenoses observed.

Discussion

We describe a unique case of a SCA that doesn’t conform to any category within the modified Lipton’s classification. Symptoms are speculated to arise from the compression of the SCA between the aorta and pulmonary artery during physical exertion. Additionally, hypoperfusion from the hypoplastic left coronary branch in the anterior wall warrants consideration. It’s paramount to meticulously evaluate the risk of sudden cardiac death when treating patients with a SCA. For high-risk patients, coronary artery bypass grafting should be contemplated.

For our patient, given the clinical context, pharmacological treatment optimization was chosen.
Association of Epigenetic Age and Everyday Discrimination With Longitudinal Trajectories of Chronic Health Conditions in Older Adults
Authors: Mutambudzi Miriam , Brown Maria T , Chen Nai-Wei
Published: January 2024

We investigated the strength of the association between baseline epigenetic age, everyday discrimination, and trajectories of chronic health conditions (CHCs) across 3 study waves, among adults 50 years of age and older. We used 2016–2020 data from the Health and Retirement Study (HRS). Data for the PhenoAge and DNAm GrimAge second-generation epigenetic clocks were from the 2016 HRS Venous Blood Study. CHC trajectories were constructed using latent class growth curve models. Multinomial logistic regression models assessed the strength of the association between accelerated epigenetic age, everyday discrimination, and the newly constructed CHC trajectories for participants with complete data (n = 2 893). In the fully adjusted model, accelerated PhenoAge (relative risk ratios [RRR] = 2.53, 95% confidence interval [95% CI] = 1.81, 3.55) and DNAm GrimAge (RRR = 2.79, 95% CI = 1.95, 4.00) were associated with classification into the high CHC trajectory class. Racial disparities were evident, with increased risk of classification into the high trajectory class for Black (PhenoAge: RRR = 1.69, 95% CI = 1.07, 2.68) and reduced risk for Hispanic (PhenoAge: RRR = 0.32, 95% CI = 0.16, 0.64; DNAm GrimAge: RRR = 0.34, 95% CI = 0.17, 0.68), relative to White participants. Everyday discrimination was associated with classification into the medium-high (RRR = 1.28, 95% CI = 1.00, 1.64) and high (RRR = 1.52, 95% CI = 1.07, 2.16) trajectory classes in models assessing DNAm GrimAge. More research is needed to better understand the longitudinal health outcomes of accelerated aging and adverse social exposures. Such research may provide insights into vulnerable adults who may need varied welfare supports earlier than the mandated chronological age for access to federal and state resources.
The ethics of engaged scholarship in a complex world
Authors: Avant Deborah , Barma Naazneen H , Demartino George F , Grabel Ilene
Published: January 2024

Social scientists must grapple with how to pursue knowledge about an uncertain and complex world. This challenge is accentuated when scholars wish to engage responsibly with policy-makers and the public in the interests of social betterment. In this article, we use the scholarly literature on uncertainty and complexity to examine how these issues complicate the practice of engaged scholarship. We ground our analysis in interviews with publicly engaged scholars on the ethical challenges they have faced and how they have navigated uncertainties and complexities in their applied work in peace and security. We identify four broad ethical dilemmas associated with publicly engaged scholarship and propose ways that scholars might begin to navigate these challenges. Our analysis urges greater acceptance of uncertainty and complexity in the social science community and associated epistemic humility in collective scholarship, pedagogy and public engagement.
What do we talk about when we talk about the ‘return’ of geopolitics?
Authors: Nickel Carsten
Published: January 2024

Western public and academic debates stipulate a ‘return’ of geopolitics, but confusion reigns over its substantial meaning. Recent scholarship has increasingly equated the term with the imperialist context in which ‘classical’ geopolitics first emerged, unmasking its spatial determinism but also losing sight of its geographic dimension. Today, geopolitics vaguely combines notions of systemic power competition in a neo-realist sense with constructivist ideas about spatially expansive authoritarianism. To address the resulting confusion, the article conducts interpretive process tracing and analyses how, throughout the twentieth century, classical geopolitics spatially substantiated systemic dynamics of shifting international power balances and broader political programmes such as imperialism, especially via competition on and over the Eurasian landmass. The article examines how, amid renewed competition with Russia and China over Eurasia—as well as doubts over the leanings of European and Asian middle powers in this contest—these traditional concerns reverberate even in contemporary western geopolitical debates characterized by vaguer definitions. This approach helps differentiate geopolitics from standard theories of International Relations and highlights how our unease with spatial arguments under liberal universalism drives today's largely metaphorical use of the term. American Cold War geopolitics, leveraged in defence of domestic democracy, emerges as a thought-provoking contrast.
Unstable environmental conditions constrain the fine-tune between opsin sensitivity and underwater light in an Amazon forest stream fish
Authors: de Almeida Borghezan Elio , da Silva Pires Tiago Henrique , Zuanon Jansen , Sugiura Hideki , Kohshima Shiro , Kishida Takushi
Published: January 2024

Visual adaptations can stem from variations in amino acid composition, chromophore utilization, and differential opsin gene expression levels, enabling individuals to adjust their light sensitivity to environmental lighting conditions. In stable environments, adaptations often involve amino acid substitutions, whereas in unstable conditions, differential gene expression may be a more relevant mechanism. Amazon forest streams present diverse underwater lighting conditions and experience short-term water colour fluctuations. In these environments, it is less likely for genetic and amino acid sequences to undergo modifications that tailor opsin proteins to the prevailing lighting conditions, particularly in species having several copies of the same gene. The sailfin tetra, Crenuchus spilurus, inhabits black and clear water Amazon forest streams. The long-wavelength sensitivity (LWS) is an important component for foraging and courtship. Here, we investigated LWS opsin genes in the sailfin tetra. Three copies of LWS1 and two copies of LWS2 genes were found. The maximum absorbance wavelength (λmax) estimated from the amino acid sequences of LWS1 genes exhibited variation among the different copies. In contrast, the copies of LWS2 genes showed identical expected λmax values. Although the amino acid positions affecting λmax varied among LWS genes, they remained consistent among populations living in different water colours. The relative expression levels of LWS genes differed between gene copies. While not formally tested, our results suggest that in fluctuating environments, visual adaptations may primarily stem from alterations in gene expression profiles and/or chromophore usage rather than precise genetic tuning of protein light sensitivity to environmental lighting conditions.
Ca2+ signatures in symbiosis: another level of dynamism for this key messenger
Authors: Dong Xiaoxu , Gifford Miriam L , Su Chao
Published: January 2024

This article comments on:

Binci F, Offer E, Crosino A, Sciascia I, Kleine-Vehn J, Genre A, Giovannetti M, Navazio L. 2024. Spatially and temporally distinct Ca2+ changes in Lotus japonicus roots orient fungal-triggered signalling pathways towards symbiosis or immunity. Journal of Experimental Botany 75,605–619.
Clinical Relevance of Human Immunodeficiency Virus Low-level Viremia in the Dolutegravir era: Data From the Viral Load Cohort North-East Lesotho (VICONEL)
Authors: Kohler Maurus , Brown Jennifer A , Tschumi Nadine , Lerotholi Malebanye , Motaboli Lipontso , Mokete Moliehi , Chammartin Frédérique , Labhardt Niklaus D
Published: January 2024

Background

Human immunodeficiency virus low-level viremia (LLV) is associated with subsequent treatment failure at least with non nucleoside reverse transcriptase inhibitor (NNRTI)-containing antiretroviral therapy. Data on implications of LLV occurring under dolutegravir, which has largely replaced NNRTIs in Africa, are scarce, however.

Methods

We included adults with human immunodeficiency virus in Lesotho who had ≥2 viral loads (VLs) taken after ≥6 months of NNRTI- or dolutegravir-based antiretroviral therapy. Within VL pairs, we assessed the association of viral suppression (<50 copies/mL) and low- and high-range LLV (50–199 and 200–999 copies/mL, respectively) with virological failure (≥1000 copies/mL) using a mixed-effects regression model. Participants could contribute VLs to the NNRTI and the dolutegravir group.

Results

Among 18 550 participants, 12 216 (65.9%) were female and median age at first VL included was 41.2 years (interquartile range, 33.4–51.5). In both groups, compared with a suppressed VL, odds of subsequent virological failure were higher for low-range LLV (NNRTI: adjusted odds ratio; 95% confidence interval: 1.9; 1.4–2.4 and dolutegravir: 2.1; 1.3–3.6) and high-range LLV (adjusted odds ratio; 95% confidence interval, 4.2; 3.1–5.7 and 4.4; 2.4–7.9).

Conclusions

In the dolutegravir era, LLV remains associated with virological failure, endorsing the need for close clinical and laboratory monitoring of those with a VL ≥50 copies/mL.
Mutation of AtPME2, a pH-Dependent Pectin Methylesterase, Affects Cell Wall Structure and Hypocotyl Elongation
Authors: Hocq Ludivine , Habrylo Olivier , Sénéchal Fabien , Voxeur Aline , Pau-Roblot Corinne , Safran Josip , Fournet Françoise , Bassard Solène , Battu Virginie , Demailly Hervé , Tovar José C , Pilard Serge , Marcelo Paulo , Savary Brett J , Mercadante Davide , Njo Maria Fransiska , Beeckman Tom , Boudaoud Arezki , Gutierrez Laurent , Pelloux Jérôme , Lefebvre Valérie
Published: January 2024

Pectin methylesterases (PMEs) modify homogalacturonan’s chemistry and play a key role in regulating primary cell wall mechanical properties. Here, we report on Arabidopsis AtPME2, which we found to be highly expressed during lateral root emergence and dark-grown hypocotyl elongation. We showed that dark-grown hypocotyl elongation was reduced in knock-out mutant lines as compared to the control. The latter was related to the decreased total PME activity as well as increased stiffness of the cell wall in the apical part of the hypocotyl. To relate phenotypic analyses to the biochemical specificity of the enzyme, we produced the mature active enzyme using heterologous expression in Pichia pastoris and characterized it through the use of a generic plant PME antiserum. AtPME2 is more active at neutral compared to acidic pH, on pectins with a degree of 55–70% methylesterification. We further showed that the mode of action of AtPME2 can vary according to pH, from high processivity (at pH8) to low processivity (at pH5), and relate these observations to the differences in electrostatic potential of the protein. Our study brings insights into how the pH-dependent regulation by PME activity could affect the pectin structure and associated cell wall mechanical properties.