bluuebunny/crossref_metadata_2025 huggingface dataset:
Hall physics during magnetic reconnection with collision effect
Authors: Shu Yukang , Lu San , Lu Quanming , Huang Kai , Wang Rongsheng , Ding Weixing
Published: February 2024

The Hall effect, decoupling between the ion and electron motions, is the core mechanism triggering fast reconnection. In plasmas with collision effects such as laboratory facilities, collision can suppress the Hall effect and influence the triggering of fast reconnection. Here, by conducting a series of kinetic simulations with varying collision parameters, we show that collisions can suppress the electron outflow, impairing the quadrupole Hall magnetic field. Besides, collision weakens the inflow of magnetic flux by reducing the charge separation and increasing the thermal pressure at the reconnection site, leading to a reduction of the Hall electric field. As the collisionality becomes larger, the Hall electric field diminishes more easily than the Hall magnetic field. We propose that the quadrupolar Hall magnetic field can be a significant indicator in reflecting Hall reconnection.
Simulations of tokamak edge plasma turbulent fluctuations based on a minimal 3D model
Authors: Umansky M V , Cohen B I , Joseph I
Published: February 2024

A new simulation model for tokamak boundary plasma, SOLT3D, is implemented in the BOUT++ framework (Dudson et al 2009 Comput. Phys. Commun.
180 1467). The simulation model includes a set of dynamic equations describing collisional boundary plasma and neutral gas in the tokamak scrape-off layer and divertor region. The model is verified against standard linear plasma instabilities and available nonlinear results. For L-mode like conditions, SOLT3D reproduces characteristics of boundary plasma turbulent fluctuations that are similar to published experimental data, in terms of the amplitude and spatial dependence of the fluctuations. It also reproduces realistic plasma fluxes on material surfaces and expected Bohm-like effective radial transport. Plasma fluctuations inferred from the simulations imply inevitably a significant level of intrinsic ‘noise’ for axisymmetric tokamak plasma transport modeling, introducing errors on the order of unity. In particular, the toroidally averaged atomic rates below 5–10 eV are strongly modified by turbulent plasma fluctuations, which should significantly affect the standard axisymmetric modeling of the tokamak edge plasma and divertor.
The surface force balance: direct measurement of interactions in fluids and soft matter
Authors: Hayler Hannah J , Groves Timothy S , Guerrini Aurora , Southam Astrid , Zheng Weichao , Perkin Susan
Published: February 2024

Over the last half-century, direct measurements of surface forces have been instrumental in the exploration of a multitude of phenomena in liquid, soft, and biological matter. Measurements of van der Waals interactions, electrostatic interactions, hydrophobic interactions, structural forces, depletion forces, and many other effects have checked and challenged theoretical predictions and motivated new models and understanding. The gold-standard instrument for these measurements is the surface force balance (SFB), or surface forces apparatus, where interferometry is used to detect the interaction force and distance between two atomically smooth planes, with 0.1 nm resolution, over separations from about 1 µm down to contact. The measured interaction force vs. distance gives access to the free energy of interaction across the fluid film; a fundamental quantity whose general form and subtle features reveal the underlying molecular and surface interactions and their variation. Motivated by new challenges in emerging fields of research, such as energy storage, biomaterials, non-equilibrium and driven systems, innovations to the apparatus are now clearing the way for new discoveries. It is now possible to measure interaction forces (and free energies) with control of electric field, surface potential, surface chemistry; to measure time-dependent effects; and to determine structure in situ. Here, we provide an overview the operating principles and capabilities of the SFB with particular focus on the recent developments and future possibilities of this remarkable technique.
Enhancing levitation force of superconductors through wavelength optimization in Halbach permanent magnet arrays
Authors: Liu Xiaoning , Si Mayin , Ke Zhihao , Deng Zigang
Published: February 2024

Optimizing the wavelength (γ) of the Halbach array permanent magnet guideway (PMG) in superconducting maglev systems can improve levitation performance without consuming additional materials. The value of γ impacts the external field intensity

H

e

and gradient

∇

H

e

generated by the PMG. The total amount of magnetic field energy is fixed, and the γ essentially regulates the distribution of this energy. Reducing γ concentrates more magnetic field on the PMG surface, resulting in larger force and stiffness when the levitation height approaches zero. To validate this conclusion, experiments, approximate calculations and numerical simulations have been in all employed. However, excessive reducing γ at higher heights is not ideal as it tends to distribute most of the field energy below the desired height. The approximate method in this paper indicates that the levitation force is positively correlated with

(

H

e

2

2

H

p

−

H

e

)
∇

H

e

. Therefore, the objective is to determine the optimal γ that maximizes this index. Optimal values for γ at different heights have been identified, offering guidance for PMG design. Additionally, applying these findings to two existing PMGs results in 18% and 8.6% augmentation in levitation force respectively. Furthermore, a fully optimized PMG design has the potential to achieve a levitation force of nearly 10 kN m−1, while keeping the cross-sectional areas of the PMG and SC restricted to 4450 mm2 and 2500 mm2, respectively.
Flux transfer circuits breaking conventional limit in transfer coefficient based on a negative inductance of a π-junction
Authors: Higashi Masayuki , Li Feng , Tanaka Masamitsu , Fujimaki Akira
Published: February 2024

We have demonstrated transfer coefficients breaking the conventional limit in flux transfer circuits (FTCs) by introducing a π-phase-shifted Josephson junction (π-junction), where the FTCs include an input/output inductor. According to the current-phase relationship of a π-junction, the π-junction behaves as an inductor with intrinsically negative kinetic inductance. When a single-π-junction superconducting quantum interference device (π-SQUID) in which a geometric inductor is placed in parallel with the π-junction is formed, a current flowing on the inductor, that is, the internal flux is increased against an input current or an input flux supplied externally to the π-SQUID in case that the π-SQUID shows no hysteresis in characteristics of internal-external flux. The FTC under investigation (π-FTC) is composed of two identical π-SQUIDs sharing a π-junction. The magnitude of the internal flux exceeds that of the external flux in the π-SQUID near zero external flux. Using this effect, the transfer coefficients are expected to be increased in the π-FTCs. Numerical analysis for π-FTCs reveals that the transfer coefficients exceed the conventional limit in a wide range of input currents corresponding to the input flux, although the negative kinetic inductance depends on the magnitude of the input. We made several π-FTCs for critical currents of the π-junctions of 50 πA and 60 πA. The output flux was measured by constructing a flux-locked loop. The experimentally obtained ratios of the transfer coefficients of the π-FTCs to the coefficient of the conventional FTC made on the same chip agree with the numerical results, which supports the negative kinetic inductances cause the increased coefficients breaking the conventional limit. Because the transfer coefficient is almost independent of input currents, we believe that the π-FTCs are applicable for strengthening not only couplings used in quantum annealers or SQUID sensors but also couplings used in superconductor digital circuits.
A hydrodynamical description of Bose liquid with fractional exclusion statistics
Authors: Fei Zhaoyu , Chen Yu
Published: February 2024

Hydrodynamical systems are usually taken as chaotic systems with fast relaxations. It is counter intuitive for ‘ideal’ gas to have a hydrodynamical description. We find that a hydrodynamical model of one-dimensional

|

Φ

|

6

theory shares the same ground state density profile, density-wave excitation, as well as the similar dynamical and statistical properties with the Calogero–Sutherland model in thermodynamic limit when their interaction strengths matches each other. The interaction strength g
0 in

|

Φ

|

6

theory is then the index of fractional statistics. Although the model is interacting in Bose liquid sense, but it shows integrability with periodical coherent evolution. We also discussed the fractional statistics emerges from the

|

Φ

|

6

theory.
Universality of oscillatory instabilities in fluid mechanical systems
Authors: García-Morales Vladimir , Tandon Shruti , Kurths Jürgen , Sujith R I
Published: February 2024

Oscillatory instability emerges amidst turbulent states in experiments in various turbulent fluid and thermo-fluid systems such as aero-acoustic, thermoacoustic and aeroelastic systems. For the time series of the relevant dynamic variable at the onset of the oscillatory instability, universal scaling behaviors have been discovered in experiments via the Hurst exponent and certain spectral measures. By means of a center manifold reduction, the spatiotemporal dynamics of these real systems can be mapped to a complex Ginzburg–Landau equation with a linear global coupling. In this work, we show that this model is able to capture the universal behaviors of the route to oscillatory instability, elucidating it as a transition from defect to phase turbulence mediated by the global coupling.
Dynamical analysis of a new 3D chaotic system: non-equilibrium point, conservative, rotationally hidden attractor
Authors: Zhao Boyu , Ye Xiaolin
Published: February 2024

A novel three-dimensional chaotic system is proposed in this paper. The nonlinear features are enhanced by adding e-exponent function to make the system behavior more complex and diverse. Through calculation and experimental verification, it is found that the system is a conservative system without equilibrium point, and this kind of system may produce hidden dynamic behavior. Therefore, four different dynamic analysis tools are chosen to simulate the possible hidden dynamics. The rotation factor is used to create some new models on the original system equation. With constantly adjustments of the rotation angle, the different resulting rotational hidden attractors are used to further prove that such chaos exists in the new proposed system. In the end, the realization of DSP shows the feasibility of this system in practical applications.
Chaotic model and control of an atmospheric convective system coupled with large-scale circulation
Authors: Zhang Fangfang , Liu Wenzhe , Wu Lin , Li Jie
Published: February 2024

Large-scale weather systems affect or determine the generation, development and movement of small- and medium-scale convective weather systems, and the understanding of their influence mechanism is of great significance for the prediction and forecasting of small- and medium-scale convective systems. From the perspective of dynamics, based on the Lorenz–Stenflo model describing convective systems and the Lorenz84 model describing low-order atmospheric circulation, we constructed a chaotic model of an atmospheric convective system considering large-scale circulation, analyzed the influence of the system parameters on the convective system, and designed a state feedback controller to adjust the convective motion. For the constructed convective weather system model, the existence and boundedness of its solution were analyzed, the Hamiltonian quantity was solved, the dynamic characteristics of the Lyapunov exponent, bifurcation diagram, attractor phase diagram and other methods were used to analyze its dynamic characteristics, the physical significance of its dynamic behavior was discussed, and the influence mechanism of the system parameters on convective weather was given. Additionally, the temperature difference between the upper and lower air currents is changed by the state feedback method, which provides a feasible scheme for adjusting the intensity of convective motion. The simulation experiments show that the chaotic model can explain and reveal the complex dynamic behavior of large-scale weather circulation in small- and medium-scale convective systems, which is of great significance for improving the prediction accuracy of convective systems in local areas, and feedback control can obtain the desired convective motion state.
Frequency-dependent membrane polarization across neocortical cell types and subcellular elements by transcranial alternating current stimulation
Authors: Huang Xuelin , Wei Xile , Wang Jiang , Yi Guosheng
Published: February 2024

Objective. Transcranial alternating current stimulation (tACS) is a non-invasive brain stimulation technique that directly interacts with ongoing brain oscillations in a frequency-dependent manner. However, it remains largely unclear how the cellular effects of tACS vary between cell types and subcellular elements. Approach. In this study, we use a set of morphologically realistic models of neocortical neurons to simulate the cellular response to uniform oscillating electric fields (EFs). We systematically characterize the membrane polarization in the soma, axons, and dendrites with varying field directions, intensities, and frequencies. Main results. Pyramidal cells are more sensitive to axial EF that is roughly parallel to the cortical column, while interneurons are sensitive to axial EF and transverse EF that is tangent to the cortical surface. Membrane polarization in each subcellular element increases linearly with EF intensity, and its slope, i.e. polarization length, highly depends on the stimulation frequency. At each frequency, pyramidal cells are more polarized than interneurons. Axons usually experience the highest polarization, followed by the dendrites and soma. Moreover, a visible frequency resonance presents in the apical dendrites of pyramidal cells, while the other subcellular elements primarily exhibit low-pass filtering properties. In contrast, each subcellular element of interneurons exhibits complex frequency-dependent polarization. Polarization phase in each subcellular element of cortical neurons lags that of field and exhibits high-pass filtering properties. These results demonstrate that the membrane polarization is not only frequency-dependent, but also cell type- and subcellular element-specific. Through relating effective length and ion mechanism with polarization, we emphasize the crucial role of cell morphology and biophysics in determining the frequency-dependent membrane polarization. Significance. Our findings highlight the diverse polarization patterns across cell types as well as subcellular elements, which provide some insights into the tACS cellular effects and should be considered when understanding the neural spiking activity by tACS.
Taxonomic fingerprints of Plantago atrata Hoppe – a Review
Authors: Ivanov G , Kercheva A , Tosheva A , Yordanova Z , Zhiponova M
Published: February 2024

Plantago atrata Hoppe (dark plantain; Plantaginaceae) is a lesser-studied narrow-leaved Plantain species and in the present review, we summarize the knowledge about the plant. The distribution of this alpine species and reported subspecies is described. Emphasis is made on P. atrata taxonomic features including botanical characteristics and phylogenetic discrimination via DNA barcoding and metabolic composition. The ecological significance of this plant species is discussed from floristic and nutrient value points of view. The collected information would serve as a basis for further in-depth research on physiological and phytochemical aspects of P. atrata, which would enable the understanding of this plant’s high-altitude adaptation and its possible contribution to beneficial applications for other organisms.
Accumulation of microplastics in Zebra mussel (Dreissena polymorpha, Pallas, 1771) in the sand pit lake Kazichene, Bulgaria
Authors: Hongyu Zhang , Rozdina Desislava , Kozuharov Dimitar , Traykov Ivan
Published: February 2024

In recent years, microplastic contamination has received worldwide distribution and specific attention. As a result, detecting sensitive bioindicators is crucial to establish the pollution. The aim of the present study is to investigate the accumulation of microplastics in zebra mussels (Dreissena polymorpha, Pallas, 1771) from the sand pit lake Kazichene. The natural range of the zebra mussel in Bulgaria includes the Danube River delta, the Black Sea rivers and coastal lakes. However, it is considered a wide spread invasive species to inland freshwaters. The use of invasive species as bioindicators over native species is advisable in order to protect the local biodiversity. In total 20 mussels of D. polymorpha were used for the analysis. The biological tissues of the mussels were digested with the aid of 30% H2O2 at 65°C for 24 - 48 hours. Microplastics (772 pcs. in total) were detected in all zebra mussel samples, indicating microplastic contamination in Lake Kazichene. Three main shapes have been identified: fragments, fibres and pellets, with the highest proportion of the fragments. The colours of the microplastic particles found were black, red, yellow and transparent, dominated by those of black colour, followed by red. The length of the fibres found in the zebra mussels ranged from 0.25 to 5 mm. There was no strong correlation between the body length/meat weight of zebra mussels with the degree of microplastic accumulation in the mussels.
Evaluation of behavioral response of Blitopertha lineolata (Fischer von Waldheim, 1824) (Coleoptera: Rutelidae) to visual and chemical cues
Authors: Toshova Teodora , Tóth Miklós , Subchev Mitko , Abaev Vasiliy , Guéorguiev Borislav
Published: February 2024

During field trapping of Tropinota hirta (Cetoniidae) by blue traps baited with the respective floral lure regular catches Blitopertha lineolata were recorded in an experimental field in Sofia plain, Bulgaria. In order to investigate the relative importance of chemical and visual cues on the attraction response of this species, several field tests were performed using CSALOMON® VARb3k funnel traps in Sofia during 2007-2009. In 2007, we evaluated the behavioral response of the adults to four variants of traps - transparent and blue unbaited traps, and transparent and blue traps baited with the lure for T. hirta. The most numerous catches of B. lineolata were recorded in blue traps independently of the presence or absence of the floral bait. In a subsequent test we compared the attractiveness of baited traps developed for cetoiid beetle species: T. hirta, Oxythyrea funesta, Cetonia aurata and Protaetia cuprea (Cetoniidae). The most numerous catches were recorded in traps for C. aurata/P. cuprea but there was no significant difference between mean catches in these traps and traps for T. hirta. The color preference of B. lineolata was evaluated comparing the colors, white, blue, yellow, fluorescent yellow or transparent of VARb3 traps without chemical lures. Results of these tests revealed that highest mean numbers of adults were recorded in the blue traps followed by the fluorescent yellow traps in 2008, and white and yellow traps in 2009. During this study, the seasonal flight of B. lineolata in the Sofia region started at the second half of May and lasted till the beginning of July in 2007, 2008 and 2009. Blue CSALOMON® VARb3k funnel traps can be considered as an efficient tool for detection and monitoring the seasonal flight of this species. Further research is needed to find a semiochemical attractant to B. lineolata. New distributional data for this species in Bulgaria are provided as well.
Phytotoxicological assessment of AMD affected river waters in “Sredna Gora”, Bulgaria to Lepidium sativum L.
Authors: Vladimirova Mariya , Kirova Lora , Traykov Ivan
Published: February 2024

The ongoing pollution of water bodies from decommissioned mines and mining waste facilities in Bulgaria is a serious problem, leading to a contamination of river waters with heavy metals. Although the chemical analyses of acid mine drainage (AMD) affected waters provide information about their toxicity, this information is not enough to evaluate the potential impacts on the biota. For this, different biological responses are used to assess the toxicity of the polluted waters.

The goal of the research was to determine the phytotoxicity (usingLepidium sativum) of five affected river waters. The lower reaches of the rivers flow though agricultural areas and are often used for irrigation by local farmers, increasing the chance of produce contamination.

The effect of the working solutions on seed germination and primary root growth ofL. sativumwas assessed by the following indices: Relative seed germination (RSG), relative root growth (RRG) and germination index (GI, the product of RSG and RRG).

The obtained results have shown the connection between germination/root growth inhibition and concentrations of heavy metals in working solutions, but there is no connection between germination/root growth inhibition and pH levels.
Ameliorative effects of the flavonoid fustin in a rat model of trinitrobenzensulfonic acid-induced colitis
Authors: Eftimov M , Georgieva A , Pavlov D , Todorova M , Reyzov M , Nikolova M , Stefanova N , Tsaneva M , Novakovic M , Tesevic V , Valcheva-Kuzmanova S
Published: February 2024

Trinitrobenzene sulfonic acid (TNBS)-induced colitis is a widely used animal model that mimics the signs and symptoms of inflammatory bowel disease. Fustin is a flavonoid found inCotinus coggygria.

The aim of the present study was to investigate the effect of fustin isolated fromCotinus coggygriaheartwood in a rat model of TNBS-induced colitis.

In this experiment, 30 male Wistar rats were used, allocated to three groups: Control, TNBS and TNBS+F10. Colitis was induced by rectal application of TNBS. After the induction of colitis, fustin at a dose of 10 mg/kg was administered orally to TNBS+F10 group in the course of 8 days. Severity of colitis, oxidative stress and inflammation were assessed by macroscopic, histopathological, immunohistochemical and biochemical analyses.

Rats from TNBS group demonstrated severe colonic damage. Fustin treatment ameliorated most of the macroscopic and some of the histopathological indices of colonic damage, and restored the activity of the endogenous antioxidant superoxide dismutase in tissue homogenate but did not affect the signs of inflammation measured by the activity of alkaline phosphatase in serum and tissue homogenate, as well as the expression of NF-kB in the colon. In conclusion, the ameliorative effects of fustin in the experimental TNBS-induced colitis might be the result of its antioxidant properties.
Apollonian packings and Kac-Moody root systems
Authors: Whitehead Ian
Published: February 2024

We study Apollonian circle packings using the properties of a certain rank 4 indefinite Kac-Moody root system

Φ
\Phi

. We introduce the generating function

Z
(

s

)

Z(\mathbf {s})

of a packing, an exponential series in four variables with an Apollonian symmetry group, which is a symmetric function for

Φ
\Phi

. By exploiting the presence of affine and Lorentzian hyperbolic root subsystems of

Φ
\Phi

, with automorphic Weyl denominators, we express

Z
(

s

)

Z(\mathbf {s})

in terms of Jacobi theta functions and the Siegel modular form

Δ
5

\Delta _5

. We also show that the domain of convergence of

Z
(

s

)

Z(\mathbf {s})

is the Tits cone of

Φ
\Phi

, and discover that this domain inherits the intricate geometric structure of Apollonian packings.
Better than square-root cancellation for random multiplicative functions
Authors: Xu Max Wenqiang
Published: February 2024

We investigate when the better than square-root cancellation phenomenon exists for

∑

n
≤
N

a
(
n
)
f
(
n
)

\sum _{n\le N}a(n)f(n)

, where

a
(
n
)
∈

C

a(n)\in \mathbb {C}

and

f
(
n
)

f(n)

is a random multiplicative function. We focus on the case where

a
(
n
)

a(n)

is the indicator function of

R
R

rough numbers. We prove that

log
⁡
log
⁡
R
≍
(
log
⁡
log
⁡
x

)

1
2

\log \log R \asymp (\log \log x)^{\frac {1}{2}}

is the threshold for the better than square-root cancellation phenomenon to disappear.
Dynamics of cell wall-binding proteins at a single molecule level: B. subtilis autolysins show different kinds of motion
Authors: Fiedler Svenja M. , Graumann Peter L.
Published: February 2024

The bacterial cell wall is a meshwork of crosslinked peptidoglycan strands, with a thickness of up to 50 nm in Firmicutes. Little is known about how proteins move through the cell wall to find sites of enzymatic activity. Cell wall synthesis for cell elongation involves the integration of new peptidoglycan strands by integral membrane proteins, as well as the degradation of existing strands by so-called autolysins, soluble proteins that are secreted through the cell membrane. Autolysins comprise different classes of proteases and glucanases and mostly contain cell-wall binding domains in addition to their catalytic domain. We have studied dynamics of Bacillus subtilis autolysins LytC, a major endopeptidase required for lateral cell wall growth, and LytF, a peptidase acting at the newly formed division site in order to achieve separation of daughter cells. We show that both proteins, fused to moxVenus are present as three distinct populations of different diffusion constants. The fastest population is compatible with free diffusion in a crowded liquid environment, that is similar to that of cytosolic enzymes, likely reflecting autolysins diffusing through the periplasm. The medium mobile fraction can be explained by constrained motion through a polymeric substance, indicating mobility of autolysins through the wall similar to that of DNA-binding proteins within the nucleoid. The slow-mobile fraction are most likely autolysins bound to their specific substrate sites. We show that LytF is more static during exponential phase, while LytC appears to be more active during the transition to stationary phase. Both autolysins became more static in backgrounds lacking redundant other autolysins, suggesting stochastic competition for binding sites. On the other hand, lack of inhibitor IseA or autolysin CwlS lead to an altered preference for polar localization of LytF within the cell wall, revealing that inhibitors and autolysins also affect each other’s pattern of localization, in addition to their activity.
Cluster of Nontoxigenic Corynebacterium diphtheriae Infective Endocarditis and Rising Background C. diphtheriae Cases—Seattle, Washington, 2020–2023
Authors: Karmarkar Ellora N , Fitzpatrick Thomas , Himmelfarb Sarah T , Chow Eric J , Smith Hayden Z , Lan Kristine F , Matsumoto Jason , Graff Nicholas R , DeBolt Chas , Truong Thao , Bourassa Lori , Farquhar Carey , Fang Ferric C , Kim H Nina , Pottinger Paul S
Published: February 2024

Background

Nontoxigenic Corynebacterium diphtheriae, often associated with wounds, can rarely cause infective endocarditis (IE). Five patients with C. diphtheriae IE were identified within 12 months at a Seattle-based hospital system. We reviewed prior C. diphtheriae–positive cultures to determine if detections had increased over time and evaluated epidemiologic trends.

Methods

We conducted a formal electronic health record search to identify all patients aged ≥18 years with C. diphtheriae detected in a clinical specimen (ie, wound, blood, sputum) between 1 September 2020 and 1 April 2023. We collected patient demographics, housing status, comorbidities, substance-use history, and level of medical care required at detection. We extracted laboratory data on susceptibilities of C. diphtheriae isolates and on other pathogens detected at the time of C. diphtheriae identification.

Results

Between 1 September 2020 and 1 April 2023, 44 patients (median age, 44 years) had a C. diphtheriae–positive clinical culture, with most detections occurring after March 2022. Patients were predominantly male (75%), White (66%), unstably housed (77%), and had a lifetime history of injecting drugs (75%). Most C. diphtheriae–positive cultures were polymicrobial, including wound cultures from 36 (82%) patients and blood cultures from 6 (14%) patients, not mutually exclusive. Thirty-four patients (77%), including all 5 patients with C. diphtheriae IE, required hospital admission for C. diphtheriae or a related condition. Of the 5 patients with IE, 3 died of IE and 1 from COVID-19.

Conclusions

Findings suggest a high-morbidity outbreak disproportionately affecting patients who use substances and are unstably housed.
Marginal zone B cells produce ‘natural’ atheroprotective IgM antibodies in a T cell–dependent manner
Authors: Harrison James , Newland Stephen A , Jiang Wei , Giakomidi Despoina , Zhao Xiaohui , Clement Marc , Masters Leanne , Corovic Andrej , Zhang Xian , Drago Fabrizio , Ma Marcella , Ozsvar Kozma Maria , Yasin Froher , Saady Yuta , Kothari Hema , Zhao Tian X , Shi Guo-Ping , McNamara Coleen A , Binder Christoph J , Sage Andrew P , Tarkin Jason M , Mallat Ziad , Nus Meritxell
Published: February 2024

Aims

The adaptive immune response plays an important role in atherosclerosis. In response to a high-fat/high-cholesterol (HF/HC) diet, marginal zone B (MZB) cells activate an atheroprotective programme by regulating the differentiation and accumulation of ‘poorly differentiated’ T follicular helper (Tfh) cells. On the other hand, Tfh cells activate the germinal centre response, which promotes atherosclerosis through the production of class-switched high-affinity antibodies. We therefore investigated the direct role of Tfh cells and the role of IL18 in Tfh differentiation in atherosclerosis.

Methods and results

We generated atherosclerotic mouse models with selective genetic deletion of Tfh cells, MZB cells, or IL18 signalling in Tfh cells. Surprisingly, mice lacking Tfh cells had increased atherosclerosis. Lack of Tfh not only reduced class-switched IgG antibodies against oxidation-specific epitopes (OSEs) but also reduced atheroprotective natural IgM-type anti-phosphorylcholine (PC) antibodies, despite no alteration of natural B1 cells. Moreover, the absence of Tfh cells was associated with an accumulation of MZB cells with substantially reduced ability to secrete antibodies. In the same manner, MZB cell deficiency in Ldlr−/− mice was associated with a significant decrease in atheroprotective IgM antibodies, including natural anti-PC IgM antibodies. In humans, we found a positive correlation between circulating MZB-like cells and anti-OSE IgM antibodies. Finally, we identified an important role for IL18 signalling in HF/HC diet–induced Tfh.

Conclusion

Our findings reveal a previously unsuspected role of MZB cells in regulating atheroprotective ‘natural’ IgM antibody production in a Tfh-dependent manner, which could have important pathophysiological and therapeutic implications.
Qualitative analysis of UK women’s attitudes to calorie-based alcohol marketing and alcohol calorie labelling
Authors: Atkinson Amanda M , Meadows Beth R , Hobin Erin , Vanderlee Lana Mae , Sumnall Harry
Published: February 2024

Mandatory standardized nutritional information on alcoholic drinks such as energy, or calorie labelling, is a population-level public health measure aimed at addressing obesity and alcohol consumption. In the UK, such measures are not a statutory requirement, but some alcohol brands do include references to calories on their products and in their marketing materials, as a marketing strategy to encourage sales and consumption. This article presents findings of semi-structured individual (N = 43) and group (N = 9) interviews with 78 women living in the UK that aimed to gain insight into their attitudes towards calorie-based alcohol brand marketing, and alcohol calorie labelling (ACL) as a health policy. Three themes are presented that outline how women rejected calorie marketing and labelling; the potential positive and unintended impact on alcohol consumption and dietary/eating practices; and how views on calorie labelling were intertwined with women’s attitudes towards marketing that draws on calorie messaging. A feminist anti-diet discourse, as well as a discourse of pleasure through alcohol consumption, was at play in women’s accounts, which may limit the intended aims of ACLs. It is concluded that ACLs should be considered within the wider commercial context of alcohol marketing that draws on calories to promote sales and consumption, consideration of the gendered factors that may lead some to reject ACLs as a health policy, and the potential for unintended consequences.
The contribution of Dutch municipalities to stimulate smoke-free outdoor sports clubs: a qualitative study
Authors: Smit Rixt A , Rozema Andrea D , van de Goor Ien A M , Kunst Anton E
Published: February 2024

Local governments may play a key role in making outdoor sports clubs smoke free. This study aims to assess the activities, motives, challenges and strategies of Dutch municipalities regarding stimulating outdoor sports clubs to become smoke free. Semi-structured interviews were conducted with 19 policy officers of different municipalities in the Netherlands. The included municipalities varied in terms of region, population size and degree of urbanization. Data were analyzed using content analysis. Municipalities stimulated sports clubs to become smoke free by providing information and support and, to a lesser extent, by using financial incentives. Motives of municipalities varied from facilitating a healthy living environment for youth, responding to denormalization of smoking and aligning with goals formulated in national prevention policy. Policy officers faced several challenges, including limited capacity and funds, a reluctance to interfere with sports clubs and little support within the municipal organization. These challenges were addressed by employing various strategies such as embedding smoke-free sports in a broader preventive policy, setting a good example by creating outdoor smoke-free areas around municipal buildings, and collaborating with stakeholders in the municipality to join forces in realizing smoke-free sports clubs. Municipalities demonstrated evident motivation to contribute to a smoke-free sports environment. Currently, most municipalities fulfil an informative and supportive role, while some municipalities still explore their role and position in relation to supporting sports clubs to become smoke free. Other municipalities have established, according to them, effective strategies.
The (Self-Similar, Variational) Rolling Stones
Authors: Langharst Dylan , Ulivelli Jacopo
Published: February 2024

The interplay between variational functionals and the Brunn–Minkowski Theory is a well-established phenomenon widely investigated in the last thirty years. In this work, we prove the existence of solutions to the even logarithmic Minkowski problems arising from variational functionals, such as the first eigenvalue of the Laplacian and the torsional rigidity. In particular, we lay down a blueprint showing that the same result holds for more generic functionals by adapting the volume case from Böröczky, Lutwak, Yang, and Zhang. We show how these results imply the existence of self-similar solutions to variational flow problems à la Firey’s worn stone problem.
Visa Relaxation Policies and Potential Implications on Public Health in Africa
Authors: Komakech Allan , Baki Karl Angendu , Izudi Jonathan
Published: February 2024

In this article, we explore how Africa’s visa relaxation policies could transform public health landscapes, with the potential of increasing access to healthcare and collaborative disease control while also posing challenges in managing infectious disease spread amidst already porous borders. We also suggest recommendations to some of the challenges.
Influence of RNA circularity on Target RNA-Directed MicroRNA Degradation
Authors: Fuchs Wightman Federico , Lukin Jerónimo , Giusti Sebastián A , Soutschek Michael , Bragado Laureano , Pozzi Berta , Pierelli María L , González Paula , Fededa Juan P , Schratt Gerhard , Fujiwara Rina , Wilusz Jeremy E , Refojo Damián , de la Mata Manuel
Published: February 2024

A subset of circular RNAs (circRNAs) and linear RNAs have been proposed to ‘sponge’ or block microRNA activity. Additionally, certain RNAs induce microRNA destruction through the process of Target RNA-Directed MicroRNA Degradation (TDMD), but whether both linear and circular transcripts are equivalent in driving TDMD is unknown. Here, we studied whether circular/linear topology of endogenous and artificial RNA targets affects TDMD. Consistent with previous knowledge that Cdr1as (ciRS-7) circular RNA protects miR-7 from Cyrano-mediated TDMD, we demonstrate that depletion of Cdr1as reduces miR-7 abundance. In contrast, overexpression of an artificial linear version of Cdr1as drives miR-7 degradation. Using plasmids that express a circRNA with minimal co-expressed cognate linear RNA, we show differential effects on TDMD that cannot be attributed to the nucleotide sequence, as the TDMD properties of a sequence often differ when in a circular versus linear form. By analysing RNA sequencing data of a neuron differentiation system, we further detect potential effects of circRNAs on microRNA stability. Our results support the view that RNA circularity influences TDMD, either enhancing or inhibiting it on specific microRNAs.
RNA-binding properties orchestrate TDP-43 homeostasis through condensate formation in vivo
Authors: Scherer Natalie M , Maurel Cindy , Graus Matthew S , McAlary Luke , Richter Grant , Radford Rowan A W , Hogan Alison , Don Emily K , Lee Albert , Yerbury Justin , Francois Mathias , Chung Roger S , Morsch Marco
Published: February 2024

Insoluble cytoplasmic aggregate formation of the RNA-binding protein TDP-43 is a major hallmark of neurodegenerative diseases including Amyotrophic Lateral Sclerosis. TDP-43 localizes predominantly in the nucleus, arranging itself into dynamic condensates through liquid–liquid phase separation (LLPS). Mutations and post-translational modifications can alter the condensation properties of TDP-43, contributing to the transition of liquid-like biomolecular condensates into solid-like aggregates. However, to date it has been a challenge to study the dynamics of this process in vivo. We demonstrate through live imaging that human TDP-43 undergoes nuclear condensation in spinal motor neurons in a living animal. RNA-binding deficiencies as well as post-translational modifications can lead to aberrant condensation and altered TDP-43 compartmentalization. Single-molecule tracking revealed an altered mobility profile for RNA-binding deficient TDP-43. Overall, these results provide a critically needed in vivo characterization of TDP-43 condensation, demonstrate phase separation as an important regulatory mechanism of TDP-43 accessibility, and identify a molecular mechanism of how functional TDP-43 can be regulated.
Structure of native four-repeat satellite III sequence with non-canonical base interactions
Authors: Chen Erin , Trajkovski Marko , Lee Hyun Kyung , Nyovanie Samantha , Martin Kailey N , Dean William L , Tahiliani Mamta , Plavec Janez , Yatsunyk Liliya A
Published: February 2024

Tandem-repetitive DNA (where two or more DNA bases are repeated numerous times) can adopt non-canonical secondary structures. Many of these structures are implicated in important biological processes. Human Satellite III (HSat3) is enriched for tandem repeats of the sequence ATGGA and is located in pericentromeric heterochromatin in many human chromosomes. Here, we investigate the secondary structure of the four-repeat HSat3 sequence 5′-ATGGA ATGGA ATGGA ATGGA-3′ using X-ray crystallography, NMR, and biophysical methods. Circular dichroism spectroscopy, thermal stability, native PAGE, and analytical ultracentrifugation indicate that this sequence folds into a monomolecular hairpin with non-canonical base pairing and B-DNA characteristics at concentrations below 0.9 mM. NMR studies at 0.05–0.5 mM indicate that the hairpin is likely folded-over into a compact structure with high dynamics. Crystallographic studies at 2.5 mM reveal an antiparallel self-complementary duplex with the same base pairing as in the hairpin, extended into an infinite polymer. The non-canonical base pairing includes a G–G intercalation sandwiched by sheared A–G base pairs, leading to a cross-strand four guanine stack, so called guanine zipper. The guanine zippers are spaced throughout the structure by A–T/T–A base pairs. Our findings lend further insight into recurring structural motifs associated with the HSat3 and their potential biological functions.
Proprietary interests and knowing receipt: Byers v Saudi National Bank [2023] UKSC 51
Authors: Purewal Anita
Published: February 2024

The long-awaited Supreme Court ruling in Byers v Saudi National Bank has provided a welcomed judgment on an established claim in equity and trusts law, knowing receipt. The judgment not only provides guidance on an issue which has never been directly addressed at the Supreme Court level before, namely whether a continuing proprietary interest is needed for a successful claim in knowing receipt, but also provides much-needed clarification on the underlying basis and application of knowing receipt claims moving forwards, guidance that will be renowned for years to come.
Candidate Kidney Protective Strategies for Patients Undergoing Major Abdominal Surgery: A Secondary Analysis of the RELIEF Trial Cohort
Authors: McIlroy David R. , Feng Xiaoke , Shotwell Matthew , Wallace Sophia , Bellomo Rinaldo , Garg Amit X. , Leslie Kate , Peyton Philip , Story David , Myles Paul S.
Published: February 2024

Background

Acute kidney injury (AKI) is common after major abdominal surgery. Selection of candidate kidney protective strategies for testing in large trials should be based on robust preliminary evidence.

Methods

A secondary analysis of the Restrictive versus Liberal Fluid Therapy in Major Abdominal Surgery (RELIEF) trial was conducted in adult patients undergoing major abdominal surgery and randomly assigned to a restrictive or liberal perioperative fluid regimen. The primary outcome was maximum AKI stage before hospital discharge. Two multivariable ordinal regression models were developed to test the primary hypothesis that modifiable risk factors associated with increased maximum stage of postoperative AKI could be identified. Each model used a separate approach to variable selection to assess the sensitivity of the findings to modeling approach. For model 1, variable selection was informed by investigator opinion; for model 2, the Least Absolute Shrinkage and Selection Operator (LASSO) technique was used to develop a data-driven model from available variables.

Results

Of 2,444 patients analyzed, stage 1, 2, and 3 AKI occurred in 223 (9.1%), 59 (2.4%), and 36 (1.5%) patients, respectively. In multivariable modeling by model 1, administration of a nonsteroidal anti-inflammatory drug or cyclooxygenase-2 inhibitor, intraoperatively only (odds ratio, 1.77 [99% CI, 1.11 to 2.82]), and preoperative day-of-surgery administration of an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker compared to no regular use (odds ratio, 1.84 [99% CI, 1.15 to 2.94]) were associated with increased odds for greater maximum stage AKI. These results were unchanged in model 2, with the additional finding of an inverse association between nadir hemoglobin concentration on postoperative day 1 and greater maximum stage AKI.

Conclusions

Avoiding intraoperative nonsteroidal anti-inflammatory drugs or cyclooxygenase-2 inhibitors is a potential strategy to mitigate the risk for postoperative AKI. The findings strengthen the rationale for a clinical trial comprehensively testing the risk–benefit ratio of these drugs in the perioperative period.

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Treatment of large femoral and tibial bone defects with Plate-assisted Bone Segment Transport (PABST)
Authors: Freischmidt Holger , Guehring Thorsten , Thomé Patrick , Armbruster Jonas , Reiter Gregor , Grützner Paul Alfred , Nolte Philip-Christian
Published: February 2024

OBJECTIVES:

The purposes of this study were to assess clinical and radiographic outcomes following Plate-assisted Bone Segment Transport (PABST) in large bone defects of the lower extremities.

METHODS:

Design:

Retrospective study of prospectively collected data.

Setting:

Level-1 trauma center located in Germany.

Patient Selection Criteria:

Patients who underwent PABST and were at least one year postoperatively were included.

Outcome Measures and Comparisons:

Demographic data were collected. Radiographic apparent bone gap (RABG), time to consolidation, as well as time to full weight bearing and consolidation index were calculated. Numeric Rating Scale (NRS), Lower Extremity Functional Scale (LEFS), and complications were assessed.

RESULTS:

Fifteen patients (13 male; mean age 51 years [range, 20-75]) underwent PABST and had follow-up at a mean of 29.1 months. The tibia was affected in 8 and the femur in 7 patients. Preoperative RABG was 60 mm (IQR: 40-125) and bone defects were caused by septic non-unions in 73%. Fourteen patients (93%) demonstrated consolidated transport callus at 7.3 months (95%CI: 6-8.5) and nine patients (60%) demonstrated complete consolidation of both docking site and transport callus at 11.5 months (95%CI: 7.3-15.3). Postoperative RABG was 0.1mm (IQR: 0-0.8), consolidation index was 1.9 months/cm (95%CI: 1.3-2.5). All patients achieved full weight-bearing at 8.7 months (IQR:6.5-10.3). LEFS was 42 (95%CI: 34-50) and NRS was 3 (95%CI: 2-4). Patients treated for tibial defects had a significantly higher consolidation rate compared to patients treated for femoral defects (p=.040).

CONCLUSIONS:

PABST demonstrated high consolidation of transport callus with few complications. Although full weight-bearing was achieved in all patients, complete consolidation of the docking site was only present in 60% of cases.

Level of Evidence:

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.
An All-Arthroscopic Technique of Repairing Foveal Tears of the Triangular Fibrocartilage Complex Using a Bone Anchor–Repair Made Simple
Authors: Choudhury Muntasir Mannan , Yap Robert Tze Jin , Jiang Jackson Kian Hong , Chia Dawn Sinn Yii , Chin Andrew Yuan Hui
Published: February 2024

Traumatic foveal tears of the triangular fibrocartilage complex lead to ulnar-sided wrist pain and instability, resulting in painful motion and loss of grip strength with a severe impact on the overall function of the upper limb. Surgical repair is nothing new and has traversed through the realm of open repair to arthroscopic assisted to all arthroscopic repair techniques over the many decades, with arthroscopic repairs showing better visualization, lesser trauma, and equally favorable patient outcomes. Techniques had varied from using trans osseous tunnels to bone anchors, with or without the usage of special jigs. Here, we describe a simple and fast 3 portal arthroscopic technique of repairing the torn foveal insertion of the triangular fibrocartilage complex using a bone anchor inserted under arthroscopic and fluoroscopic guidance into the fovea. Both the dorsal and volar limbs of the triangular fibrocartilage complex are repaired arthroscopically, resulting in a strong anatomic repair resulting in a stable and pain-free wrist.