bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative investigation of low and high pelletize pressure for (Ag)x/CuTl-1223 nanoparticles-superconductor composites
Authors: Muhammad Yaseen , Rahim M , Mumtaz M , Hussain Nazir , Hussain Bahar
Published: November 2023

This article experimentally investigates the impact of silver (Ag) nano-particles inclusion and high pelletized pressure on the structural, morphological, and electrical properties of Cu0.5Tl0.5Ba2Ca2Cu3O10−δ
(noted CuTl-1223) bulk system. The nano-(Ag)
x
/CuTl-1223 composites were synthesized using a two-step solid-state reaction process with added amount of Ag nano-particles ranging from 0 to 2.0 wt% of the total mass. These nano-composites were produced at both low and high pelletize pressure of 0.202 GPa. All prepared samples were characterized using valuable techniques such as X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), Energy Dispersive Spectroscopy (EDS), Fourier Transform Infrared Spectroscopy (FTIR), and dc-resistivity measurement at low as well as high pelletized pressure, respectively. The structural investigation via the XRD technique indicated that Ag NPs did not affect the CuTl-1223 tetragonal structure, confirmed that Ag nano-particles were settled across the grain boundaries. SEM examination revealed a fine distribution of nano-sized silver (Ag) NPs among the CuTl-1223 grains, as well as improved weak-links and density of void/pores. The position of distinct vibrational oxygen modes in FTIR spectra showed no substantial alteration, indicating that the structural nature of the host CuTl-1223 phase was preserved. The electrical properties were studied using the four-point probe technique, and the activation energy were determined using Arrhenius law. The results of

ρ
−
T

measurements showed that pelletization pressure of 0.202 GPa have an impact on the critical temperature

T

c

of (Ag)
x
/CuTl-1223 composites. The superconducting critical temperature

T

c

0

was enhanced from 99 K to 107 K at high-pressure of pelletization (0.202 GPa) as compared to low pressure, with

x

= 0 ∼ 2.0 wt

%

nano-particles addition to the host CuTl-1223 phase.
Caputo-fabrizio fractional-order systems: periodic solution and stabilization of non-periodic solution with application to gunn diode oscillator
Authors: Shankar Matap , Bora Swaroop Nandan
Published: November 2023

Fractional-order autonomous systems do not possess any non-constant periodic solutions, and to the best of our knowledge, there are no existing results regarding the existence of the periodic solution for fractional-order non-autonomous systems. The main objective of this work is to fill the above gap by studying the existence of a periodic solution of the Caputo-Fabrizio fractional-order system and also to find ways to stabilize a non-periodic solution. First, by using the concepts of an equilibrium point, it is proved that an autonomous Caputo-Fabrizio system cannot admit a non-constant periodic solution. Under a similar assumption as the one for an integer-order differential system, and by using the properties of the Caputo-Fabrizio derivative, the existence of a periodic solution of a non-autonomous Caputo-Fabrizio fractional-order differential system is established. The main result is utilized in constructing and finding the periodic solution of the linear non-homogeneous Caputo-Fabrizio system. By using the result on linear systems, we derive a periodic solution of a fractional-order Gunn diode oscillator under a periodic input voltage, and observe that the diameter of the periodic orbit keeps reducing as the fractional-order continuously increases. In the end, by using the result on a linear non-homogeneous system, and by constructing a suitable linear feedback control, the solution of the linear non-homogeneous fractional-order system is stabilized to a periodic solution. An example is presented to support the obtained result. The main advantage of the proposed method over others is the simple considerations like the concept of equilibrium point and the utilization of the property of the Caputo-Fabrizio derivatives instead of other types of fractional derivatives.
General relativity in a nutshell II
Authors: Pinochet Jorge
Published: November 2023

The aim of this work is to use the notions of Riemann’s geometry introduced in Part I, to analyze the foundations of Einstein’s theory of general relativity.
Generation of mode-locked thulium doped fluoride fiber laser using graphene-zinc oxide (G-ZnO) coated dual arc-shaped fiber
Authors: Ahmad Harith , Nizamani Bilal , Seiger Lalithambikai
Published: November 2023

In this work, mode-locked laser generation at the S-band region was achieved using a graphene-zinc oxide (G-ZnO) coated dual arc-shaped fiber as a saturable absorber (SA) within a thulium-doped fluoride fiber (TDFF) ring cavity. Two-step polishing was implemented to fabricate a dual arc-shaped fiber, and a G-ZnO solution was then deposited on the dual arc region via the drop-casting method to form the SA. Mode-locked pulses were generated by incorporating the G-ZnO-based SA into the TDFF ring cavity, with the pulses having a central wavelength, 3 dB bandwidth and pulse duration of 1503.4 nm, 0.68 nm and 3.52 ps, respectively. At the maximum pump power of 202 mW, an average output power of 2.47 mW was obtained with a maximum pulse energy of 6.16 nJ and a peak power of 1.75 kW. At this pump power, the generated pulses have a frequency of 401.6 kHz with a signal-to-noise ratio (SNR) of 54 dB. The mode-locking threshold was at a pump power of 118 mW. The results obtained in this work indicate the potential of a new class of 2D composite materials which can be used as nonlinear optical devices.
Particle number and interactions in the entropic uncertainty relations
Authors: Salazar Saúl J C , Laguna Humberto G , Sagar Robin P
Published: November 2023

The dependence of the entropic uncertainty relations on particle number and on attractive and repulsive interparticle potential strengths, is examined in the ground state of coupled harmonic oscillators. The reduced entropy sums depend on the normalization constants of the position and momentum densities, which in turn depend on particle number and interaction strength. These sums exhibit maxima as the particle number is varied, when the particles are in the presence of attractive potentials. On the other hand, no maxima are observed for systems with a repulsive potential. All reduced entropy sums increase and move away from the bound with greater interactions. Consistent behaviours are observed for both reduced one- and two-variable entropy sums. Further reductions of the N-particle densities induce that the respective entropy sums are now farther away from the corresponding bounds. The interpretation of these results is that reduction and increased interaction translates into a weakening of the strength of the uncertainty principle statement. The one- and two-variable entropy sums of these systems are shown to approximate the

a
+
b
ln
N

relation, when the intensity of the one-body harmonic potential is set at the number of particles.
Influence of an external electric field on the structure and properties of domain walls in a (111)-oriented ferrite-garnet film
Authors: Vakhitov R M , Yumaguzin A R , Gridneva G T
Published: November 2023

In this study, the features of the manifestation of the flexomagnetoelectric effect in a (111)-oriented ferrite garnet film were investigated. It has been shown that, in such magnets, two types of domain walls with magnetization in domains with

M

0

∣
∣

111

are possible: a Bloch-type domain wall and a wall with a quasi-Bloch structure. The evolution of each type of domain wall in an increasing electric field with

ε
∣
∣

111

is revealed, and the characteristic stages of transformation of their structures were determined. Critical fields for their rearrangement and the corresponding values of differential and integral polarizations were found. It has been established that the presence of cubic anisotropy in a (111)-oriented film weakens the degree of manifestation of the flexomagnetoelectric effect in it.
Does NANOGrav observe a dark sector phase transition?
Authors: Bringmann Torsten , Depta Paul Frederik , Konstandin Thomas , Schmidt-Hoberg Kai , Tasillo Carlo
Published: November 2023

Gravitational waves from a first-order cosmological phase transition, at temperatures at the MeV-scale, would arguably be the most exciting explanation of the common red spectrum reported by the NANOGrav collaboration, not the least because this would be direct evidence of physics beyond the standard model. Here we perform a detailed analysis of whether such an interpretation is consistent with constraints on the released energy deriving from big bang nucleosynthesis and the cosmic microwave background. We find that a phase transition in a completely secluded dark sector with sub-horizon sized bubbles is strongly disfavoured with respect to the more conventional astrophysical explanation of the putative gravitational wave signal in terms of supermassive black hole binaries. On the other hand, a phase transition in a dark sector that subsequently decays, before the time of neutrino decoupling, remains an intriguing possibility to explain the data. From the model-building perspective, such an option is easily satisfied for couplings with the visible sector that are small enough to evade current collider and astrophysical constraints. The first indication that could eventually corroborate such an interpretation, once the observed common red spectrum is confirmed as a nHz gravitational wave background, could be the spectral tilt of the signal. In fact, the current data already show a very slight preference for a spectrum that is softer than what is expected from the leading astrophysical explanation.
WIMP decay as a possible Warm Dark Matter model
Authors: Parichha Abineet , Sethi Shiv
Published: November 2023

The Weakly Interacting Massive Particles (WIMPs) have long been the favoured Cold Dark Matter (CDM) candidate in the standard ΛCDM model. However, owing to great improvement in the experimental sensitivity in the past decade, some parameter space of the Supersymmetric (SUSY)-based WIMP model is ruled out. In addition, a massive stable WIMP as the CDM particle is also at variance with other astrophysical observables at small scales. We consider a model that addresses both these issues. In the model, the WIMP decays into a massive particle and radiation. We study the background evolution and the first order perturbation theory (coupled Einstein-Boltzmann equations) for this model and show that the dynamics can be captured by a single parameter r = mL/q, which is the ratio of the lighter mass and the comoving momentum of the decay particle. We incorporate the relevant equations in the existing Boltzmann code CLASS to compute the matter power spectra and Cosmic Microwave Background (CMB) angular power spectra. The decaying WIMP model is akin to a non-thermal Warm Dark Matter (WDM) model and suppresses matter power at small scales, which could alleviate several issues that plague the CDM model at small scales. We compare the predictions
of the model with CMB and galaxy clustering data. As the model deviates from the ΛCDM model at small scales, the evolution of the collapse fraction of matter in the universe is compared with the high-redshift Sloan Digital Sky Survey (SDSS) HI data. Both these data sets yield r ≳ 106, which
can be translated into the bounds on other parameters. In particular, we obtain the following lower bounds on the thermally-averaged self-annihilation cross-section of WIMPs, ⟨σv⟩, and the lighter mass: ⟨σv⟩ ≳ 4.9 × 10-34 cm3 sec-1 and mL
 ≳ 2.4 keV.
The lower limit on mL
is comparable to constraints on the mass of thermally-produced WDM particle. The limit on the self-annihilation cross-section greatly expands the available parameter space as compared to the stable WIMP scenario.
Multi-TeV dark matter density in the inner Milky Way halo: spectral and dynamical constraints
Authors: Zuriaga-Puig Jaume , Gammaldi Viviana , Gaggero Daniele , Lacroix Thomas , Sánchez-Conde M.A.
Published: November 2023

We develop a comprehensive study of the gamma-ray flux observed by the High Energy Stereoscopic System (H.E.S.S.) in 5 regions of the Galactic Center (GC). Motivated by previous works on a possible Dark Matter (DM) explanation for the TeV cut-off observed by H.E.S.S. in the innermost ∼ 15 pc of the Galaxy, we aim to constrain the DM distribution up to a radius of ∼ 450 pc from the GC. In this region, the benchmark approach (e.g. cosmological simulations and Galactic dynamics studies) fails to produce a strong prediction of the DM profile. Within our proof-of-concept analysis, we use DRAGON to model the diffuse background emission and determine upper limits on the density distribution of thermal multi-TeV Weakly Interactive Massive Particles (WIMPs), compatible with the observed gamma-ray flux. The results are in agreement with the hypothesis of an enhancement of the DM density in the GC with respect to the benchmark Navarro-Frenk-White (NFW) profile (γ = 1) and allow us to exclude profiles with an inner slope cuspier than γ ≳ 1.3. We also investigate the possibility that such an enhancement could be related to the existence of a DM spike associated with the supermassive black hole Sgr A* at the GC. We find out that the existence of an adiabatic DM spike smoothed by the scattering off of WIMPs by the bulge stars may be consistent with the observed gamma-ray flux if the spike forms on an underlying generalized NFW profile with γ ≲ 0.8, corresponding to a spike slope of γsp-star = 1.5 and spike radius of R
sp-stars ∼ 25 30 pc. Instead, in the extreme case of the instantaneous growth of the black hole, the underlying profile could have up to γ ∼ 1.2, a corresponding γsp-inst = 1.4 and R
sp-inst ∼  15–25 pc. Finally, the results of our analysis of the total DM mass enclosed within the S2 orbit (updated with new GRAVITY data) are less stringent than the spectral analysis. Our work aims to guide future studies of the GC region, with both current and next generation of telescopes. In particular, the next Cherenkov Telescope Array will be able to scan the GC region with improved flux sensitivity and angular resolution.
Fast and effortless computation of profile likelihoods using CONNECT
Authors: Nygaard Andreas , Holm Emil Brinch , Hannestad Steen , Tram Thomas
Published: November 2023

The frequentist method of profile likelihoods has recently received renewed attention in the field of cosmology. This is because the results of inferences based on the latter may differ from those of Bayesian inferences, either because of prior choices or because of non-Gaussianity in the likelihood function. Consequently, both methods are required for a fully nuanced analysis. However, in the last decades, cosmological parameter estimation has largely been dominated by Bayesian statistics due to the numerical complexity of constructing profile likelihoods, arising mainly from the need for a large number of gradient-free optimisations of the likelihood function.

In this paper, we show how to accommodate the computational requirements of profile likelihoods using the publicly available neural network framework connect together with a novel modification of the gradient-based basin-hopping optimisation algorithm. Apart from the reduced evaluation time of the likelihood due to the neural network, we also achieve an additional speed-up of 1–2 orders of magnitude compared to profile likelihoods computed with the gradient-free method of simulated annealing, with excellent agreement between the two. This allows for the production of typical triangle plots normally associated with Bayesian marginalisation within cosmology (and previously unachievable using likelihood maximisation because of the prohibitive computational cost). We have tested the setup on three cosmological models: the ΛCDM model, an extension with varying neutrino mass, and finally a decaying cold dark matter model. Given the default precision settings in connect, we achieve a high precision in χ2 with a difference to the results obtained by class of Δχ2 ≈ 0.2 (and, importantly, without any bias in inferred parameter values) — easily good enough for profile likelihood analyses.
Corrigendum to “Electromagnetically induced transparency via localized surface plasmon mode-assisted hybrid cavity QED”
Authors: Li 李 Xiaomiao 晓苗 , Liu 刘 Famin 发民 , Li 李 Zigeng 子更 , Zhu 朱 Hongyan 虹燕 , Wang 王 Fan 帆 , Zhong 钟 Xiaolan 晓岚
Published: November 2023

We would like to point out the misprinted Fig. 3 in our published paper [Chin. Phys. B 32, 114205 (2023)]. Since only orders of subfigures need to be corrected and the main results of the published paper are correct, we present the correct figure in this corrigendum.
Applying Hybrid Clustering in Pulsar Candidate Sifting with Multi-modality for FAST Survey
Authors: You Zi-Yi , Pan Yun-Rong , Ma Zhi , Zhang Li , Xiao Shuo , Zhang Dan-Dan , Dang Shi-Jun , Zhao Ru-Shuang , Wang Pei , Dong Ai-Jun , Jiang Jia-Tao , Leng Ji-Bing , Li Wei-An , Li Si-Yao
Published: November 2023

Pulsar search is always the basis of pulsar navigation, gravitational wave detection and other research topics. Currently, the volume of pulsar candidates collected by the Five-hundred-meter Aperture Spherical radio Telescope (FAST) shows an explosive growth rate that has brought challenges for its pulsar candidate filtering system. Particularly, the multi-view heterogeneous data and class imbalance between true pulsars and non-pulsar candidates have negative effects on traditional single-modal supervised classification methods. In this study, a multi-modal and semi-supervised learning based on a pulsar candidate sifting algorithm is presented, which adopts a hybrid ensemble clustering scheme of density-based and partition-based methods combined with a feature-level fusion strategy for input data and a data partition strategy for parallelization. Experiments on both High Time Resolution Universe Survey II (HTRU2) and actual FAST observation data demonstrate that the proposed algorithm could excellently identify pulsars: On HTRU2, the precision and recall rates of its parallel mode reach 0.981 and 0.988 respectively. On FAST data, those of its parallel mode reach 0.891 and 0.961, meanwhile, the running time also significantly decreases with the increment of parallel nodes within limits. Thus, we can conclude that our algorithm could be a feasible idea for large scale pulsar candidate sifting for FAST drift scan observation.
Application of machine learning in MOFs for gas adsorption and separation
Authors: Yang Chao , Qi Jingjing , Wang Anquan , Zha Jingyu , Liu Chao , Yao Shupeng
Published: November 2023

Metal–organic frameworks (MOFs) with high specific surface area, permanent porosity and extreme modifiability had great potential for gas storage and separation applications. Considering the theoretically nearly infinite variety of MOFs, it was difficult but necessary to achieve high-throughput computational screening (HTCS) of high-performance MOFs for specific applications. Machine learning (ML) was a field of computer science where one of its research directions was the effective use of information in a big data environment, focusing on obtaining hidden, valid and understandable knowledge from huge amounts of data, and had been widely used in materials research. This paper firstly briefly introduced the MOFs databases and related algorithms for ML, followed by a detailed review of the research progress on HTCS of MOFs based on ML according to four classes of descriptors, including geometrical, chemical, topological and energy-based, for gas storage and separation, and finally a related outlook was presented. This paper aimed to deepen readers’ understanding of ML-based MOF research, and to provide some inspirations and help for related research.
Characteristics of the SOL ion-to-electron temperature ratio on the J-TEXT tokamak with different plasma configurations
Authors: LI 李 Cunkai 存凯 , LIANG 梁 Yunfeng 云峰 , JIANG 江 Zhonghe 中和 , ZHOU 周 Song 松 , HUA 华 Jiankun 建坤 , YANG 阳 Jie 杰 , YANG 杨 Qinghu 庆虎 , KNIEPS Alexander , DREWS Philipp , XU 徐 Xin 鑫 , MAO 毛 Feiyue 飞越 , XIE 谢 Wei 伟 , YANG 杨 Yutong 雨桐 , GUO 郭 Jinlong 金龙 , LI 李 Yangbo 杨波 , REN 任 Zhengkang 正康 , CHEN 陈 Zhipeng 志鹏 , WANG 王 Nengchao 能超 , Team the J-TEXT
Published: November 2023

Accurate measurement of the average plasma parameters in the edge region, including the temperature and density of electrons and ions, is critical for understanding the characteristics of the scrape-off layer (SOL) and divertor plasma transport in magnetically confined fusion research. On the J-TEXT tokamak, a multi-channel retarding field analyzer (RFA) probe has been developed to study average plasma parameters in the edge region under various poloidal divertor and island divertor configurations. The edge radial profile of the ion-to-electron temperature ratio, τ
i/e, has been determined, which gradually decreases as the SOL ion self-collisionality,

, increases. This is broadly consistent with what has been observed previously from various tokamak experiments. However, the comparison of experimental results under different configurations shows that in the poloidal divertor configuration, even under the same

, τ
i/e in the SOL region becomes smaller as the distance from the X-point to the target plate increases. In the island divertor configuration, τ
i/e near the O-point is higher than that near the X-point at the same

, and both are higher than those in the limiter configuration. These results suggest that the magnetic configuration plays a critical role in the energy distributions between electrons and ions at the plasma boundary.
Preliminary electromagnetic analysis of the COOL blanket for CFETR
Authors: LU 鲁 Shuailing 帅领 , MA 马 Xuebin 学斌 , LIU 刘 Songlin 松林
Published: November 2023

The supercritical CO2 cOoled Lithium-Lead (COOL) blanket has been designed as one advanced blanket candidate for the Chinese Fusion Engineering Test Reactor (CFETR). This work focuses on the electromagnetic (EM) loads (Maxwell force and Lorentz force) acting on the COOL blanket, which are important mechanical loads in further structural analysis of the COOL blanket. A 3D electromagnetic analysis is performed using the ANSYS finite element method to obtain EM loads on the COOL blanket in this study. At first, the magnetic scalar potential (MSP) method is used to obtain the magnetic field and the Maxwell force on the COOL blanket. Then, the magnetic vector potential (MVP) method is performed during a plasma disruption event to get the eddy current distribution. At last, a multi-step method is adopted for the calculation of the Lorentz force and the torque. The maximum Lorentz forces of inboard and outboard blanket structural components are 5624 kN and 2360 kN respectively.
Highly reactive metakaolin: a multi-parameter optimization by response surface methodology
Authors: Hamisi Hashimu , Jande Yusufu Abeid Chande , Hilonga Askwar
Published: November 2023

Multi-parameter effect consideration during metakaolin conversion gives the best optimum processing conditions. Kaolin deposits have different properties, which makes it vital to establish optimum conditions for a distinctive kaolin deposit. The Response Surface Methodology under the Box-Behnken Design has been adopted in the current study to optimize the processing conditions for kaolin-to-metakaolin conversion. The temperature of 765 °C, the rate of 10 °C min−1, and 6.46 h of soaking were the optimum conditions for yielding the highly reactive (1382.15 mg Ca (OH)2/g) metakaolin. The kaolin sample’s distinctive reflections on two theta degrees at 14.32° and 29.03° proved that kaolinite was present. However, x-ray diffraction suggested that the optimized metakaolin was lacking those reflections. The Fourier-transformation infrared spectroscopy confirmed the presence of kaolinite in the sample with wave number range at the bands 3692, 3650, and 3620 cm−1, which disappeared to form a broad band in this region, which validates the formation of reactive amorphous metakaolin.
Design of a high gain antenna array for intelligent transportation system application
Authors: Hung Pham Viet , Nguyen Dai Duong , Le Minh Thuy , Nguyen Quoc Cuong
Published: November 2023

The design of a 1 × 9 linear asymmetrical printed dipole antenna array for intelligent transportation systems applications is proposed in this paper. The ground planes of two printed dipole antennas are connected together for miniaturization. The proposed antenna array obtained a large -10 dB reflection coefficient bandwidth, up to 17.6% at a center frequency of 5.8 GHz. It also acquired an efficiency of 87.5% at 5.8 GHz, with a gain of 10.16 dBi.
The mid-transition in the electricity sector: impacts of growing wind and solar electricity on generation costs and natural gas generation in Alberta
Authors: Pearson Kristina M E , Hastings-Simon Sara
Published: November 2023

In response to climate change, electricity grids are decreasing their carbon intensity with the addition of wind and solar variable renewable energy generation (VREN). This leads to a mid-transition period, where renewable energy is unable to satisfy electricity demand without contributions from other fossil sources such as natural gas, but also generates sufficiently to constrain conventional generation—changing their operating and market conditions. We use a simplified copper plate model, which scales up and down historical wind and solar generation, to examine how and when the patterns and generation costs for fossil fuel power could change by the increasing capacities of VREN on the relatively isolated Alberta electricity grid. We find that beginning at 20% VREN an increasingly diverse range and reduced hours of dispatched capacity is necessitated from the existing generation. However, even as capacity factors for fossil fuel generation decrease their costs remain reasonable and we found this to be a low-cost pathway for achieving moderate to deep emission reduction goals. A full 86% of demand could be met with VREN before generation costs exceeded 100$/MWh, allowing for an emissions reduction of 28.4–9 million tonnes yr−1 of CO2eq, on a lifecycle basis. In order to integrate the renewable generation, new and existing fossil fuel units will require market rules that incentivise flexibility and ensure they remain in place throughout the transitionary period as they are crucial to balance variable renewable generation.
Seeing the forest (plot) for the trees—the importance of evidence synthesis in older adult care
Authors: Shenkin Susan D , Quinn Terence J
Published: November 2023

Systematically reviewing all the available evidence and then creating summary analyses of the pooled data is the foundation of evidence-based practice. Indeed, this evidence synthesis approach informs much of the care of older adults in hospital and community. It is perhaps no surprise that the journal Age and Ageing is a frequent platform for publishing research papers based on systematic review and synthesis. This research has evolved substantially from the early days of evidence-based medicine and the Cochrane Collaboration. The traditional approach would be a quantitative summary, calculated using pair-wise meta-analysis of randomised controlled trials of drug versus placebo, or a synthesis of observational studies to create summaries of prevalence, associations and outcomes. Methods have evolved and newer techniques such as scoping reviews, test accuracy meta-analysis and qualitative synthesis are all now available. The sophistication of these methods is driven in part by the increasingly complex decisions that need be made in contemporary older adult care. Age and Ageing continues to champion established and novel evidence synthesis approaches, and in the accompanying Collection exemplars of these differing methods are presented and described. Whilst there is marked heterogeneity in the techniques used, the consistent and defining feature of all these papers is the desire to comprehensively, and critically summarise the evidence in order to answer the most pertinent questions regarding older adult care.
Non-stressful temperature changes affect transgenerational phenotypic plasticity across the life cycle of Arabidopsis thaliana plants
Authors: Authier Ailén , Cerdán Pablo , Auge Gabriela
Published: November 2023

Background and Aims

Plants respond in a plastic manner to seasonal changes, often resulting in adaptation to environmental variation. Although much is known about how seasonality regulates developmental transitions within generations, transgenerational effects of non-stressful environmental changes are only beginning to be unveiled. This study aimed to evaluate the effects of ambient temperature changes on the expression of transgenerational plasticity in key developmental traits of Arabidopsis thaliana plants.

Methods

We grew Columbia-0 plants in two contrasting temperature environments (18 and 24 °C) during their whole life cycles, or the combination of those temperatures before and after bolting (18–24 and 24–18 °C) across two generations. We recorded seed germination, flowering time and reproductive biomass production for the second generation, and seed size of the third generation.

Key Results

The environment during the whole life cycle of the first generation of plants, even that experienced before flowering, influenced the germination response and flowering time of the second generation. These effects showed opposing directions in a pattern dependent on the life stage experiencing the cue in the first generation. In contrast, the production of reproductive biomass depended on the immediate environment of the progeny generation. Finally, the seed area of the third generation was influenced positively by correlated environments across generations.

Conclusions

Our results suggest that non-stressful environmental changes affect the expression of key developmental traits across generations, although those changes can have contrasting effects depending on the parental and grandparental life stage that perceives the cue. Thus, transgenerational effects in response to non-stressful cues might influence the expression of life-history traits and potential adaptation of future generations.
Applications of genome-scale metabolic models to investigate microbial metabolic adaptations in response to genetic or environmental perturbations
Authors: Carter Elena Lucy , Constantinidou Chrystala , Alam Mohammad Tauqeer
Published: November 2023

Environmental perturbations are encountered by microorganisms regularly and will require metabolic adaptations to ensure an organism can survive in the newly presenting conditions. In order to study the mechanisms of metabolic adaptation in such conditions, various experimental and computational approaches have been used. Genome-scale metabolic models (GEMs) are one of the most powerful approaches to study metabolism, providing a platform to study the systems level adaptations of an organism to different environments which could otherwise be infeasible experimentally. In this review, we are describing the application of GEMs in understanding how microbes reprogram their metabolic system as a result of environmental variation. In particular, we provide the details of metabolic model reconstruction approaches, various algorithms and tools for model simulation, consequences of genetic perturbations, integration of ‘-omics’ datasets for creating context-specific models and their application in studying metabolic adaptation due to the change in environmental conditions.
Dopamine receptor D2 regulates genes involved in germ cell movement and sperm motility in rat testes
Authors: Raut Sanketa , Khambata Kushaan , Singh Dipty , Balasinor Nafisa H
Published: November 2023

The function of dopamine receptor D2 (D2R) is well associated with sperm motility; however, the physiological role of D2R present on testicular cells remains elusive. The aim of the present study is to delineate the function of testicular D2R. Serum dopamine levels were found to decrease with age, whereas testicular D2R expression increased. In rat testicular sections, D2R immunolabeling was observed in interstitial cells, spermatogonia, spermatocytes and mature elongated spermatids, whereas tyrosine hydroxylase immunolabeling was selectively detected in Leydig cells. In vitro seminiferous tubule culture following bromocriptine (D2R agonist) treatment resulted in decreased cAMP levels. Microarray identified 1077 differentially expressed genes (511 up-regulated, 566 down-regulated). The majority of differentially expressed genes were present in post-meiotic cells including early and late spermatids, and sperm. Gene ontology elucidated processes related to extra-cellular matrix to be enriched and was supported by differential expression of various collagens and laminins, thereby indicating a role of dopamine in extra-cellular matrix integrity and transport of spermatids across the seminiferous epithelium. Gene ontology and enrichment map also highlighted cell/sperm motility to be significantly enriched. Therefore, genes involved in sperm motility functions were further validated by RT-qPCR. Seven genes (Akap4, Ccnyl1, Iqcf1, Klc3, Prss55, Tbc1d21, Tl18) were significantly up-regulated, whereas four genes (Dnah1, Dnah5, Clxn, Fsip2) were significantly down-regulated by bromocriptine treatment. The bromocriptine-stimulated reduction in seminiferous tubule cyclic AMP and associated changes in spermatid gene expression suggests that dopamine regulates both spermatogenesis and spermiogenesis within the seminiferous epithelium, and spermatozoa motility following spermiation, as essential processes for fertility.
Changes in cerebellar output abnormally modulate cortical myoclonus sensorimotor hyperexcitability
Authors: Latorre Anna , Rocchi Lorenzo , Paparella Giulia , Manzo Nicoletta , Bhatia Kailash P , Rothwell John C
Published: November 2023

Cortical myoclonus is produced by abnormal neuronal discharges within the sensorimotor cortex, as demonstrated by electrophysiology. Our hypothesis is that the loss of cerebellar inhibitory control over the motor cortex, via cerebello-thalamo-cortical connections, could induce the increased sensorimotor cortical excitability that eventually causes cortical myoclonus. To explore this hypothesis, in the present study we applied anodal transcranial direct current stimulation over the cerebellum of patients affected by cortical myoclonus and healthy controls and assessed its effect on sensorimotor cortex excitability. We expected that anodal cerebellar transcranial direct current stimulation would increase the inhibitory cerebellar drive to the motor cortex and therefore reduce the sensorimotor cortex hyperexcitability observed in cortical myoclonus.

Ten patients affected by cortical myoclonus of various aetiology and 10 aged-matched healthy control subjects were included in the study. All participants underwent somatosensory evoked potentials, long-latency reflexes and short-interval intracortical inhibition recording at baseline and immediately after 20 min session of cerebellar anodal transcranial direct current stimulation. In patients, myoclonus was recorded by the means of surface EMG before and after the cerebellar stimulation.

Anodal cerebellar transcranial direct current stimulation did not change the above variables in healthy controls, while it significantly increased the amplitude of somatosensory evoked potential cortical components, long-latency reflexes and decreased short-interval intracortical inhibition in patients; alongside, a trend towards worsening of the myoclonus after the cerebellar stimulation was observed. Interestingly, when dividing patients in those with and without giant somatosensory evoked potentials, the increment of the somatosensory evoked potential cortical components was observed mainly in those with giant potentials.

Our data showed that anodal cerebellar transcranial direct current stimulation facilitates—and does not inhibit—sensorimotor cortex excitability in cortical myoclonus syndromes. This paradoxical response might be due to an abnormal homeostatic plasticity within the sensorimotor cortex, driven by dysfunctional cerebello-thalamo-cortical input to the motor cortex. We suggest that the cerebellum is implicated in the pathophysiology of cortical myoclonus and that these results could open the way to new forms of treatment or treatment targets.
The Steatosis-Associated Fibrosis Estimator (SAFE) score for assessing significant liver fibrosis in patients with psoriasis
Authors: Chularojanamontri Leena , Panjapakkul Waratchaya , Paringkarn Teerapat , Hutachoke Thrit , Chaiyabutr Chayada , Silpa-archa Narumol , Wongpraparut Chanisada , Bandidniyamanon Wimolrak , Charatcharoenwitthaya Phunchai
Published: November 2023

Background

There is an urgent need for noninvasive tests to identify patients with psoriasis at risk of significant liver fibrosis.

Objectives

To externally validate the ability of the Steatosis-Associated Fibrosis Estimator (SAFE) score to detect significant liver fibrosis in patients with psoriasis using transient elastography (TE) as a reference.

Methods

We analysed data from 75 patients with psoriasis, including TE, SAFE score, Fibrosis-4 Index (FIB-4) and Nonalcoholic Fatty Liver Disease Fibrosis Score (NFS). Significant liver fibrosis was defined as TE values ≥ 7.1 kPa. Diagnostic accuracy was assessed using the area under the receiver operating characteristic curve (AUROC).

Results

Fifteen patients (20%) exhibited significant liver fibrosis. The AUROCs for the SAFE and FIB-4 scores were 0.82 [95% confidence interval (CI) 0.67–0.97] and 0.62 (95% CI 0.45–0.79), respectively. The SAFE score outperformed the FIB-4 Index (P = 0.01) but was comparable with the NFS (P = 0.05) in predicting significant fibrosis. Using thresholds of < 0, 0 to < 100 and ≥ 100, the SAFE score categorized 36, 24 and 15 patients into low, intermediate and high-risk groups for significant fibrosis, respectively. The negative predictive value for excluding significant fibrosis with a SAFE score of < 0 was 94.4%, and the positive predictive value for diagnosing significant fibrosis with a SAFE score of > 100 was 53.3%. The duration of psoriasis, joint involvement and methotrexate treatment did not affect the diagnostic ability of the SAFE score whereas age of the patient did.

Conclusions

The SAFE score demonstrated good accuracy in assessing clinically significant fibrosis among patients with psoriasis. This score should prove valuable for risk stratification and patient management in dermatology practice.
Neuromelanin-sensitive MRI of the substantia nigra distinguishes bipolar from unipolar depression
Authors: Kuai Xinping , Shao Dandan , Wang Shengyu , Wu Pu-Yeh , Wu Yan , Wang Xuexue
Published: November 2023

Depression in bipolar disorder (BD-II) is frequently misdiagnosed as unipolar depression (UD) leading to inappropriate treatment and downstream complications for many bipolar sufferers. In this study, we evaluated whether neuromelanin-MR signal and volume changes in the substantia nigra (SN) can be used as potential biomarkers to differentiate BD-II from UD. The signal intensities and volumes of the SN regions were measured, and contrast-to-noise ratio (CNR) to the decussation of the superior cerebellar peduncles were calculated and compared between healthy controls (HC), BD-II and UD subjects. Results showed that compare to HC, both BD-II and UD subjects had significantly decreased CNR and increased volume on the right and left sides. Moreover, the volume in BD-II group was significantly increased compared to UD group. The area under the receiver operating characteristic curve (AUC) for discriminating BD from HC was the largest for the Volume-L (AUC, 0.85; 95% confidence interval [CI]: 0.77, 0.93). The AUC for discriminating UD from HC was the largest for the Volume-L (AUC, 0.76; 95% CI: 0.65, 0.86). Furthermore, the AUC for discriminating BD from UD was the largest for the Volume-R (AUC, 0.73; 95% CI: 0.62, 0.84). Our findings suggest that neuromelanin-sensitive magnetic resonance imaging techniques can be used to differentiate BD-II from UD.
STREI: a new index of right heart function in isolated severe tricuspid regurgitation by speckle-tracking echocardiography
Authors: Hinojar Rocio , Fernández-Golfín Covadonga , González Gómez Ariana , García-Martin Ana , Monteagudo Juan Manuel , García Lunar Inés , García Sebastian Cristina , Pardo Ana , Sanchez Recalde Angel , Zamorano Jose Luis
Published: November 2023

Aims

Right ventricular (RV) performance determines clinical management in severe tricuspid regurgitation (TR). Right atrial (RA) function complements RV assessment in TR. This study aimed to design a novel index by speckle-tracking echocardiography (STREI index) integrating RA and RV strain information and to evaluate the clinical utility of combining RV and RA strain for prediction of cardiovascular (CV) outcomes.

Methods and results

Consecutive patients with at least (≥) severe TR evaluated in the Heart Valve Clinic (n = 300) were prospectively included. An additional independent TR cohort was included for external validation (n = 50). STREI index was developed with the formula: [2 ∗ RV-free wall longitudinal strain (RV-FWLS)] + reservoir RA strain (RASr). The composite endpoint included hospital admission due to heart failure and all-cause mortality. A total of 176 patients with ≥severe TR were finally included. STREI index identified a higher percentage of patients with RV dysfunction compared with conventional parameters. After a median follow-up of 2.2 years (interquartile range: 12–41 months), a total of 38% reached the composite endpoint. STREI values were predictors of outcomes independently of TR severity and RV dimensions. The combination of prognostic cut-off values of RASr (<10%) and RV-FWLS (>−20%) (STREI stratification) stratified four different groups of risk independently of TR severity, RV dimensions, and clinical status (adj HR per stratum 1.89 (1.4–2.34), P < 0.001). Pre-defined cut-off values achieved similar prognostic performance in the validation cohort (n = 50).

Conclusion

STREI index is a novel parameter of RV performance that independently predicts CV events. The combination of RA and RV strain stratifies better patients’ risk, reflecting a broader effect of TR on right heart chambers.
A simple fragility fracture risk score for type 2 diabetes patients: a derivation, validation, comparison, and risk stratification study
Authors: Chuan Fengning , Gao Youyuan , Liao Kun , Ye Xin , Mei Mei , Tian Wenqing , Li Rong , Zhou Bo
Published: November 2023

Objectives

The aims of this study were to develop and validate 2 simple scores for stratification of the risks of (1) any fragility (AF) and (2) major osteoporotic fracture (MOF) in type 2 diabetes (T2D) patients; we also compared the performance of these scores with that of the Fracture Risk Assessment Tool (FRAX) and its adjustments.

Design and methods

In this longitudinal cohort study, 1855 patients with T2D were enrolled from January 2015 to August 2019. Cox proportional hazard regression was used to model the 5-year risk of AF and MOF. These scores were internally validated using a bootstrap resampling method of 1000.

Results

During a median follow-up of 5 years, 119 (6.42%) cases of AF and 92 (4.96%) cases of MOFs were identified. Both the concordance index (C-index) and calibration plots indicated improved identification performance using the newly established scores. Furthermore, these scores also showed improved outcomes regarding the decision curve analysis (DCA) and area under the curve (AUC) compared to the widely used FRAX and its derivatives. More importantly, these scores successfully separated T2D patients into risk groups according to significant differences in fracture incidence.

Conclusions

These novel scores enable simple and reliable fracture risk stratification in T2D patients. Future work is needed to validate these findings in external cohort(s).
Look left, look right: censoring in clinical research
Authors: Groenwold Rolf H H , Dekkers Olaf M
Published: November 2023

In this methodology editorial, the problem of censored survival (or time-to-event) data in clinical research is discussed. In case of censored observations, part of the observation time for some participants in a study is unobserved, which means that measures such as an average survival time cannot be calculated. Instead, censored survival time should explicitly be accounted for in the analysis of a study, for example using the Kaplan–Meier method. Implications of censoring and how to deal with it in the analysis of a study or when reading a research paper are discussed.
Dynamic electrocardiogram changes are a novel risk marker for sudden cardiac death
Authors: Pham Hoang Nhat , Holmstrom Lauri , Chugh Harpriya , Uy-Evanado Audrey , Nakamura Kotoka , Zhang Zijun , Salvucci Angelo , Jui Jonathan , Reinier Kyndaron , Chugh Sumeet S
Published: November 2023

Background and Aims

Electrocardiogram (ECG) abnormalities have been evaluated as static risk markers for sudden cardiac death (SCD), but the potential importance of dynamic ECG remodelling has not been investigated. In this study, the nature and prevalence of dynamic ECG remodelling were studied among individuals who eventually suffered SCD.

Methods

The study population was drawn from two prospective community-based SCD studies in Oregon (2002, discovery cohort) and California, USA (2015, validation cohort). For this present sub-study, 231 discovery cases (2015–17) and 203 validation cases (2015–21) with ≥2 archived pre-SCD ECGs were ascertained and were matched to 234 discovery and 203 validation controls based on age, sex, and duration between the ECGs. Dynamic ECG remodelling was measured as progression of a previously validated cumulative six-variable ECG electrical risk score.

Results

Oregon SCD cases displayed greater electrical risk score increase over time vs. controls [+1.06 (95% confidence interval +0.89 to +1.24) vs. −0.05 (−0.21 to +0.11); P < .001]. These findings were successfully replicated in California [+0.87 (+0.7 to +1.04) vs. −0.11 (−0.27 to 0.05); P < .001]. In multivariable models, abnormal dynamic ECG remodelling improved SCD prediction over baseline ECG, demographics, and clinical SCD risk factors in both Oregon [area under the receiver operating characteristic curve 0.770 (95% confidence interval 0.727–0.812) increased to area under the receiver operating characteristic curve 0.869 (95% confidence interval 0.837–0.902)] and California cohorts.

Conclusions

Dynamic ECG remodelling improved SCD risk prediction beyond clinical factors combined with the static ECG, with successful validation in a geographically distinct population. These findings introduce a novel concept of SCD dynamic risk and warrant further detailed investigation.