bluuebunny/crossref_metadata_2025 huggingface dataset:
Third-order transport coefficients of ion swarms
Authors: Viehland Larry A. , Ducasse Emerson , Cordier Michelle , Trout Aaron , Dashdorj Jamiyanaa
Published: November 2021

Mobility and diffusion coefficients are generally extracted from experimental measurements of ion arrival time distributions using tensors of ranks one and two, i.e., in terms of the diffusion equation that is equivalent to Fick’s second law. The theory is extended here to tensors of rank three. It is shown that under customary circumstances, the generalized diffusion equation only contains a single third-order transport coefficient. This equation is used to generate synthetic data for ions moving through a pure gas. The mobility and diffusion coefficients and third-order transport coefficients inferred from these data are compared with values used to simulate the arrival time distribution. Finally, an existing computer program has been modified in order to compute one component of the third-order transport coefficient, and this program has been applied to Li+ in He.
Stronger three-phonon interactions revealed by molecular dynamics in materials with restricted phase space
Authors: Zhang Cunzhi , Zeng Zezhu , Sun Qiang , Chen Yue
Published: November 2021

Utilizing molecular dynamics (MD) simulations based on the highly precise force-fields, we find that phonon scattering strengths induced by the cubic anharmonicity can be significantly underestimated by the perturbation theory (PT) approach in materials with sizable frequency gaps or branch bunching. We trace this result to the additional three-phonon scatterings in MD enabled by the fluctuating phonon energy and the continuous energy exchange between modes. These channels are essential to accurately evaluate the zone-center phonon linewidth in boron arsenide as compared to the experiment and could noticeably lower the lattice thermal conductivity of beryllium telluride and tungsten carbide. Accordingly, due to the stronger three-phonon scatterings, four-phonon scatterings would become less important than previously believed in this type of material. Moreover, our work emphasizes the different phonon scattering processes in MD and PT simulations, offering new insights for an improved description of anharmonic properties.
Effect of deep level defects on CdZnTe detector internal electric field and device performance
Authors: Qiu Panhui , Min Jiahua , Liang Xiaoyan , Zhang Jijun , Xie Chen , Song Xiaolong , Feng Chengjie , Wang Shulei , Shen Yue , Wang Linjun
Published: November 2021

Cadmium zinc telluride (CZT) is an ideal material for room temperature nuclear radiation detection, but CZT crystals of high quality and low defects concentration are difficult to obtain. Therefore, in order to improve the performance of the CZT detector, the working conditions of the CZT detector could be appropriately changed to make the internal electric field of the CZT detector close to uniform distribution so as to improve the electron transport performance. In this paper, alpha induced transient charge analysis has been used to study the internal electric field of the CZT detector, and deep level defects in CZT were linked with internal electric field distribution. Based on the process, a variety of deep level defects on electron trapping and detrapping by changing the temperature, the output waveform change of charge sensitive preamplifier (the pulse height spectra for alpha radiation at different temperatures) was observed, and then the effects of deep level defects on electron mobility (μe), electron transport time (TR), the internal electric field, and the electron collection efficiency of the CZT detector were analyzed. The experimental results indicated that the influence of deep level defects was a main factor to the internal electric field in the range of −140 to 40 °C. As the temperature rises, the influence of these defects weakens, μe and electron collection efficiency both increase, and internal electric field distribution tends to be uniform. Moreover, with the further increasing temperature (−40 to 20 °C), μe decreased and internal electric field distribution became fluctuating, but electron collection efficiency was basically unchanged, which suggested that the influence of lattice vibration in the range of −40 to 20 °C turned to be the main factor. The above conclusions demonstrated that although the CZT detector has excellent room temperature detection ability, room temperature was not its optimal working temperature due to the influence of high concentration deep level defects. At −20 °C, the CZT detector presented the highest electron collection efficiency and maximum which limited the influence of deep level defects on electron transport, performing the optimal properties.
Growing two-dimensional single crystals of organic semiconductors on liquid surfaces
Authors: Chen Zheng , Duan Shuming , Zhang Xiaotao , Hu Wenping
Published: November 2021

Two-dimensional (2D) organic semiconducting single crystals (OSSCs) combine the advantages of OSSCs and 2D molecular materials, and currently, are an important and hot research topic in the field of organic optoelectronics and 2D materials. Growth of large-sized 2D OSSCs with controlled thickness is highly important for fundamental research and practical application, which is still a challenging task. Liquid surfaces can provide ideal platforms for growth of large-scale and layer-controlled 2D OSSCs because their surfaces are molecularly flat and free-defect, the “coffee-ring” effect can be effectively suppressed on liquid surfaces, and the improved spread area of organic semiconductor solutions on liquid surfaces. This perspective concentrates on recent advances in the growth of large-area and layer-controlled 2D OSSCs on liquid surfaces; the optoelectronic applications based on 2D OSSCs, as well as the challenges and outlooks in the field, are also discussed.
Transient nonlinear Rayleigh–Bénard convection with single-mode initiation
Authors: Tyvand Peder A. , Nøland Jonas Kristiansen
Published: November 2021

Transient nonlinear convection in a finite Prandtl number fluid heated uniformly from below is studied analytically and numerically. We consider the simple geometry of a square cavity with normal-mode compatible boundary conditions. By design, only the marginal state of convection onset contributes to the initial condition for the two-dimensional supercritical convection. The thermal amplitude and the flow amplitude are taken as two independent initial conditions. There are two ways of initiation: (i) soft start with a very small initial amplitude, leading to early exponential growth. (ii) Kick-started transient convection with relatively large initial amplitudes, by which we perform a small-time expansion for benchmarking. Seemingly complicated transient flow occurs with a kick-start where the initial spin and the initial buoyancy torque are in conflict. However, the intricate spiraling flow decays after a couple of reversals of flow directions, and a steady convection settles. This is due to the strict antisymmetry of the temperature perturbation around the mid-point of the cavity, in combination with the symmetry of the flow field.
Toward the theory of resonant-tunneling triode and tetrode with CNT–graphene grids
Authors: Davidovich Michael V. , Nefedov Igor S. , Glukhova Olga E. , Slepchenkov Michael M.
Published: November 2021

A stationary model is proposed for calculating the tunneling current in a vacuum resonant-tunneling triode and tetrode with control grids. The model is based on the solution of the stationary Schrödinger equation by the method of transfer matrices with the calculation of the potential energy profile in a structure with several electrodes by the method of multiple images. The model provides for the inclusion of one or two grids in the structure, particularly of those under the same voltage. For such a structure with a double quantum well, resonant tunneling is obtained and the possibility of the existence of current densities up to 1013 A/m2 is shown. The structures can be used as high-current sources or as elements of oscillator circuits.
On port-Hamiltonian formulations of 3-dimensional compressible Newtonian fluids
Authors: Mora Luis A. , Le Gorrec Yann , Matignon Denis , Ramirez Hector , Yuz Juan I.
Published: November 2021

In this manuscript, a general formulation of 3-dimensional compressible fluids based on the port-Hamiltonian framework is presented, both for isentropic and non-isentropic assumptions, describing the energy flux between the mechanical, chemical, and thermal domains, with an explicit characterization of the first and the second law of thermodynamics. For isentropic fluids, the conversion of kinetic energy into heat by viscous friction is considered as energy dissipation associated with the rotation and compression of the fluid. A dissipative port-Hamiltonian formulation is derived for this class of fluids, including vorticity boundary conditions in the port variables. For non-isentropic fluids, we consider a fluid mixture with multiple chemical reactions. To describe the energy fluxes, we propose a pseudo port-Hamiltonian formulation, which includes the rate of irreversible entropy creation by heat flux, chemical reaction, diffusion of matter, and viscous friction.
Orientation dependent stress-induced intermartensitic transformations in Ni50.3Mn28.7Ga21.0 single crystal
Authors: Czaja P. , Szczerba M. J. , Villa E. , Villa F. , Chernenko V.
Published: November 2021

Intermartensitic transformations (IMTs) between 10, 14, and 2M martensitic phases induced by the uniaxial compression and tension have been investigated using the same Ni50.3Mn28.7Ga21.0 single crystal. One series of thermomechanical measurements was carried out in a tensile configuration along the [001]c direction and another one under a compression load along the [110]c direction of the samples cut from the same single crystal. The obtained slopes of the “stress–temperature” phase diagrams of 10M → 14M and 14M → 2M IMTs are in satisfactory agreement with the Clausius–Clapeyron relationship applied for each IMT induced under compression and tension loadings. The results are important for the development of the theory of IMTs in magnetic shape memory alloys as well as for their practical applications given large superelastic strains summed over a sequence of martensite structures and a low twining stress noted uniquely for modulated martensites.
Ionic screening in bulk and under confinement
Authors: Zeman Johannes , Kondrat Svyatoslav , Holm Christian
Published: November 2021

Recent experiments have shown that the repulsive force between atomically flat, like-charged surfaces confining room-temperature ionic liquids or concentrated electrolytes exhibits an anomalously large decay length. In our previous publication [J. Zeman, S. Kondrat, and C. Holm, Chem. Commun. 56, 15635 (2020)], we showed by means of extremely large-scale molecular dynamics simulations that this so-called underscreening effect might not be a feature of bulk electrolytes. Herein, we corroborate these findings by providing additional results with more detailed analyses and expand our investigations to ionic liquids under confinement. Unlike in bulk systems, where screening lengths are computed from the decay of interionic potentials of mean force, we extract such data in confined systems from cumulative charge distributions. At high concentrations, our simulations show increasing screening lengths with increasing electrolyte concentration, consistent with classical liquid state theories. However, our analyses demonstrate that—also for confined systems—there is no anomalously large screening length. As expected, the screening lengths determined for ionic liquids under confinement are in good quantitative agreement with the screening lengths of the same ionic systems in bulk. In addition, we show that some theoretical models used in the literature to relate the measured screening lengths to other observables are inapplicable to highly concentrated electrolytes.
Ott–Antonsen ansatz for the D-dimensional Kuramoto model: A constructive approach
Authors: Barioni Ana Elisa D. , de Aguiar Marcus A. M.
Published: November 2021

Kuramoto’s original model describes the dynamics and synchronization behavior of a set of interacting oscillators represented by their phases. The system can also be pictured as a set of particles moving on a circle in two dimensions, which allows a direct generalization to particles moving on the surface of higher dimensional spheres. One of the key features of the 2D system is the presence of a continuous phase transition to synchronization as the coupling intensity increases. Ott and Antonsen proposed an ansatz for the distribution of oscillators that allowed them to describe the dynamics of the order parameter with a single differential equation. A similar ansatz was later proposed for the D-dimensional model by using the same functional form of the 2D ansatz and adjusting its parameters. In this article, we develop a constructive method to find the ansatz, similarly to the procedure used in 2D. The method is based on our previous work for the 3D Kuramoto model where the ansatz was constructed using the spherical harmonics decomposition of the distribution function. In the case of motion in a D-dimensional sphere, the ansatz is based on the hyperspherical harmonics decomposition. Our result differs from the previously proposed ansatz and provides a simpler and more direct connection between the order parameter and the ansatz.
Precise localization of DBD plasma streamers using topographically patterned insulators for maskless structural and chemical modification of surfaces
Authors: Polonskyi O. , Hartig T. , Uzarski J. R. , Gordon M. J.
Published: November 2021

Dielectric insulators with patterned topographic relief were used in dielectric barrier discharge (DBD) plasmas operating at atmospheric pressure to spatially define the formation of filamentary microdischarges (“plasma streamers”). Precise localization of microdischarge streamers is demonstrated with concomitant treatment patterns on surfaces, enabling localized etching, surface micro-texturing, and chemically and structurally induced wettability modification without the use of lithographic masks on the sample. Proof-of-concept examples include generation of arbitrary streamer patterns (lines, arrays, and letters), anisotropic etching of PMMA films, and spatial patterning of Teflon to be hydrophilic. The approach herein allows user-defined patterning of DBD streamers for subsequent modification and treatment of surfaces (e.g., roughness, wettability, etc.), materials deposition, or etching.
Mitigating voltage loss in efficient CsPbI2Br all-inorganic perovskite solar cells via metal ion-doped ZnO electron transport layer
Authors: Xu Zuxiong , Liu Xiaohui , Fu Shiqiang , Wang Jiahao , Zhang Jing , Huang Like , Hu Ziyang , Zhu Yuejin
Published: November 2021

CsPbI2Br all-inorganic perovskite solar cells (PSCs) have attracted much attention due to their suitable bandgap and outstanding thermostability. However, the large energy loss of CsPbI2Br PSCs generally endows low open circuit voltage (VOC) and unsatisfactory power conversion efficiency (PCE), which severely hamper its further development. Herein, we proposed a facile route to modify the ZnO electron transporting layer (ETL) by in situ chemical doping strategy with metal ions. The doped ZnO ETL with Pb(Ac)2 or CsAc cannot only effectively tune its energy levels, conductivity, and charge extraction but also ameliorate the crystallization and morphology of upper perovskite films. Particularly, Pb(Ac)2-doped ZnO (ZnO:Pb) induces an energy level offset of 0.15 eV relative to the conduction band of CsPbI2Br with largely reduced Ohmic loss. Thus, the highest VOC is significantly boosted to above 1.3 V for the CsPbI2Br PSCs with a champion PCE of 16.36%, while the reference PSC just yields a moderate PCE of 14.43% with a low VOC of 1.168 V. Moreover, considerable improvements in device stability are achieved for the PSCs with doped ZnO ETLs than those of the ZnO-based device. Our work provides a promising strategy to alleviate the VOC deficit toward the attainment of highly efficient and stable PSCs.
Contactless transport of sessile droplets
Authors: Jiang Zhi Wu , Chen Rui , Wu Tao , Ding Hang , Li Er Qiang
Published: November 2021

Contactless droplet transport has gained intensive attention in recent years. In this study, the motion of a sessile binary droplet or a pure water droplet under the contactless Marangoni effect has been investigated experimentally and theoretically. The concrete form of the driving force originates from the evaporation of a pure liquid “source” droplet was achieved and verified by our experimental data. For a “target” droplet consisting of pure water, we discovered a non-negligible increase in its spreading radius R during motion. Based on the experimental results, we proposed a linear approximation between R and the droplet spacing and successfully introduced its influence on the driving force calculation through the perturbation theory.
Optimized ensemble deep learning framework for scalable forecasting of dynamics containing extreme events
Authors: Ray Arnob , Chakraborty Tanujit , Ghosh Dibakar
Published: November 2021

The remarkable flexibility and adaptability of both deep learning models and ensemble methods have led to the proliferation for their application in understanding many physical phenomena. Traditionally, these two techniques have largely been treated as independent methodologies in practical applications. This study develops an optimized ensemble deep learning framework wherein these two machine learning techniques are jointly used to achieve synergistic improvements in model accuracy, stability, scalability, and reproducibility, prompting a new wave of applications in the forecasting of dynamics. Unpredictability is considered one of the key features of chaotic dynamics; therefore, forecasting such dynamics of nonlinear systems is a relevant issue in the scientific community. It becomes more challenging when the prediction of extreme events is the focus issue for us. In this circumstance, the proposed optimized ensemble deep learning (OEDL) model based on a best convex combination of feed-forward neural networks, reservoir computing, and long short-term memory can play a key role in advancing predictions of dynamics consisting of extreme events. The combined framework can generate the best out-of-sample performance than the individual deep learners and standard ensemble framework for both numerically simulated and real-world data sets. We exhibit the outstanding performance of the OEDL framework for forecasting extreme events generated from a Liénard-type system, prediction of COVID-19 cases in Brazil, dengue cases in San Juan, and sea surface temperature in the Niño 3.4 region.
Soil carbon stocks of semi-arid grasslands in northern Mexico
Authors: Jurado-Guerra Pedro , Saucedo-Terán Ruben , Morales-Nieto Carlos , Juárez-Morales Martín , Sosa-Pérez Gabriel , Álvarez-Holguín Alan
Published: November 2021

Soil organic carbon (SOC) is important, but research on SOC in Mexican semi-arid grasslands is limited. The objective of this research was to estimate SOC and develop an ecological model to predict soil carbon stocks (SCS) in the semi-arid grasslands of northern Mexico. Sites with different plant cover were selected along the Central Valleys region, and soil samples collected at two microsites (bare soil and beneath grass) at two depths (0–15 cm and 15–30 cm) and analysed for SOC. Plant cover, precipitation, temperature, soil texture and elevation were included as predictor variables to create a SCS prediction model through correlation and regression analyses. SOC varied from 0.465% ± 0.04 (mean ± s.e.m.) in low plant cover–sandy loam soil–low rainfall grasslands to 2.77% ± 0.29 in high plant cover–clay loam soil–high rainfall grasslands. The SOC was higher under grass than bare soil at all sites, while most sites showed similar SOC across soil depth. The prediction model integrated plant cover, mean annual precipitation, elevation and soil sand content (P < 0.0001) as explanatory variables, and reasonably predicted SCS (R2 = 0.798) in semi-arid grasslands of northern Mexico. Our model can be used in grasslands with similar vegetation, climate and soil in northern Mexico, although extrapolation requires caution since further validation at different sites is required.
Innovative wood use can enable carbon-beneficial forest management in California
Authors: Cabiyo Bodie , Fried Jeremy S. , Collins Brandon M. , Stewart William , Wong Jun , Sanchez Daniel L.
Published: November 2021

Significance

Natural carbon sinks can help mitigate climate change, but climate risks—like increased wildfire—threaten forests’ capacity to store carbon. California has recently set ambitious forest management goals to reduce these risks. However, management can incur carbon losses because wood residues are often burnt or left to decay. This study applies a systems approach to assess climate change mitigation potential and wildfire outcomes across forest management scenarios and several wood products. We find that innovative use of wood residues supports extensive wildfire hazard reduction and maximizes carbon benefits. Long-lived products that displace carbon-intensive alternatives have the greatest benefits, including wood building products. Our results suggest a low-cost pathway to reduce carbon emissions and support climate adaptation in temperate forests.
Ccp1-Ndc80 switch at the N terminus of CENP-T regulates kinetochore assembly
Authors: Dong Qianhua , Liu Xue-lei , Wang Xiao-hui , Zhao Yu , Chen Yu-hang , Li Fei
Published: November 2021

Significance

Precise chromosome segregation relies on kinetochores. How kinetochores are precisely assembled on centromeres through the cell cycle remains poorly understood. Centromeres in most eukaryotes are epigenetically marked by nucleosomes containing the histone H3 variant, CENP-A. Here, we demonstrated that Ccp1, an anti–CENP-A loading factor, interacts with the N terminus of CENP-T to promote the assembly of the outer kinetochore Ndc80 complex. This work further suggests that competitive exclusion between Ccp1 and Ndc80 at the N terminus of CENP-T via phosphorylation ensures precise kinetochore assembly during mitosis. In addition, CENP-T is critical for Ccp1 centromeric localization, which in turn regulates CENP-A distribution. Our results reveal a previously unrecognized mechanism underlying kinetochore assembly through the cell cycle.
Harmful algal blooms and cyanotoxins in Lake Amatitlán, Guatemala, coincided with ancient Maya occupation in the watershed
Authors: Waters Matthew Neal , Brenner Mark , Curtis Jason Hilleary , Romero-Oliva Claudia Suseth , Dix Margaret , Cano Manuel
Published: November 2021

Significance

Harmful algal blooms (HABs) are dense populations of algae and/or cyanobacteria that can harm aquatic ecosystems by reducing water column oxygen and producing toxins. Whereas HABs are well documented in modern lakes, there has been little research on HABs associated with ancient societies. We inferred the magnitude of past HABs using a sediment core from Lake Amatitlán, Guatemala, which hosted large, prehistoric Maya populations in its watershed and currently experiences toxic HABs. About 1,000 y ago, ancient Maya in the area experienced periods of intense HABs and cyanotoxin concentrations in the lake, which rivaled the degraded conditions in the water body today. Human-associated HABs have affected both modern and ancient societies and deserve attention when exploring past human–environment interactions.
Molecular mechanisms of sperm motility are conserved in an early-branching metazoan
Authors: Speer Kelsey F. , Allen-Waller Luella , Novikov Dana R. , Barott Katie L.
Published: November 2021

Significance

Reef-building corals are the keystone species of the world’s most biodiverse yet threatened marine ecosystems. Coral reproduction, critical for reef resilience, requires that coral sperm swim through the water column to reach the egg. However, little is known about the mechanisms that regulate coral sperm motility. We found here that coral sperm motility is pH dependent and that activation of motility requires signaling via the pH-sensing enzyme soluble adenylyl cyclase. This study reveals the deep conservation of a sperm activation pathway from humans to corals, presenting the first comprehensive examination of the molecular mechanisms regulating sperm motility in an early-diverging animal. These results are critical for understanding the resilience of this sensitive life stage to a changing marine environment.
Can repurposing drugs play a role in malaria control?
Authors: Cooper Roland A. , Kirkman Laura
Published: November 2021

Innovative drug treatments for malaria, optimally with novel targets, are needed to combat the threat of parasite drug resistance. As drug development efforts continue, there may be a role for a host-targeting, repurposed cancer drug administered together with an artemisinin combination therapy that was shown to improve the speed of recovery from a malaria infection.
Tracker-assisted modelling: simultaneous validation of the conservation law of energy and the work-energy theorem
Authors: Pili Unofre B , Violanda Renante R
Published: November 2021

The video of a free-falling object was analysed in Tracker in order to extract the position and time data. On the basis of these data, the velocity, gravitational potential energy, kinetic energy, and the work done by gravity were obtained. These led to a rather simultaneous validation of the conservation law of energy and the work–energy theorem. The superimposed plots of the kinetic energy, gravitational potential energy, and the total energy as respective functions of time and position demonstrate energy conservation quite well. The same results were observed from the plots of the potential energy against the kinetic energy. On the other hand, the work–energy theorem has emerged from the plot of the total work-done against the change in kinetic energy. Because of the accessibility of the setup, the current work is seen as suitable for a home-based activity, during these times of the pandemic in particular in which online learning has remained to be the format in some countries. With the guidance of a teacher, online or face-to-face, students in their junior or senior high school—as well as for those who are enrolled in basic physics in college—will be able to benefit from this work.
Dynamics of macro- and micro-bubbles induced by nanosecond discharge in liquid water
Authors: Hoffer Petr , Bílek Petr , Prukner Václav , Bonaventura Zdeněk , Šimek Milan
Published: November 2021

Gaseous micro-bubbles dispersed in liquid water represent perturbations of the homogeneity of the liquid and influence the onset of electrical discharge in the bulk liquid. In this study, we systematically examined shadowgraph images to analyse the gaseous structures occurring in response to nanosecond micro-discharges produced in deionised water. The images revealed the dynamics of resolved bubbles and unresolved sub-micrometric structures starting from nanoseconds after the onset of discharge. We provide absolute counts and the radii distributions of micro-bubbles that occur near the anode needle and show how this depends on the amplitude and repetition frequency of the applied high-voltage pulses, when the latter varies between 0.1 and 100 Hz. A systematic statistical analysis showed that the probability of producing bubble-assisted nanosecond discharge in the liquid phase rapidly increases with the discharge repetition rate (>0.5 Hz). Although the cavitation bubble formed around the anode disintegrates and disappears from the anode region within the first millisecond, the sub-micrometric structures remain for tens of milliseconds, and fragmented micro-bubbles survive even for hundreds of milliseconds. Our findings impose strict limitations on the experimental setups used to investigate the mechanisms of direct discharge in liquid water.
Strichartz estimates for the Schrödinger equation with a measure-valued potential
Authors: Erdoğan M. , Goldberg Michael , Green William
Published: November 2021

We prove Strichartz estimates for the Schrödinger equation in

R

n

\mathbb {R}^n

,

n
≥
3

n\geq 3

, with a Hamiltonian

H
=
−
Δ
+
μ

H = -\Delta + \mu

. The perturbation

μ
\mu

is a compactly supported measure in

R

n

\mathbb {R}^n

with dimension

α
>
n
−
(
1
+

1

n
−
1

)

\alpha > n-(1+\frac {1}{n-1})

. The main intermediate step is a local decay estimate in

L
2

(
μ
)

L^2(\mu )

for both the free and perturbed Schrödinger evolution.
𝐻¹ solutions on curve integrable spacetimes
Authors: Sanchez Yafet
Published: November 2021

In this work we use a framework based on scalar linear hyperbolic equations that characterises gravitational singularities as the obstruction to well-posedness. In particular, we show existence of

H

1

H^{1}

solutions on a certain class of curve integrable spacetimes. This implies that these spacetimes are not singular in the sense of obstructions to well-posedness even if their regularity is below

C

2

C^{2}

.
The feasibility and acceptability of assessing and managing sarcopenia and frailty among older people with upper limb fracture
Authors: Ibrahim Kinda , Mullee Mark A , Cox Natalie , Russell Cynthia , Baxter Mark , Tilley Simon , Yao Guiqing Lily , Zhu Shihua , Roberts Helen C
Published: November 2021

Background

sarcopenia and frailty are associated with increased risk of falls and fractures. This study evaluated the feasibility of assessing sarcopenia and frailty among older people attending fracture clinics.

Methods

patients aged 65+ years with an arm fracture attending fracture clinics in one UK city were recruited. Sarcopenia was assessed using gait speed, grip strength, skeletal muscle mass index SMI, SARC-F questionnaire and the European Working Group on Sarcopenia in Older People (EWGSOP) I and II criteria. Frailty was assessed using Fried Frailty Phenotype (FFP), FRAIL scale, PRISMA-7, electronic Frailty Index (e-FI), Clinical Frailty Score (CFS) and Study of Osteoporotic Fracture. The sensitivity and specificity of each tool was calculated against the EWGSOP II criteria (sarcopenia) and FFP (frailty). Patients identified to have either condition were referred for Comprehensive Geriatric Assessment (CGA). Interviews with 13 patients and nine staff explored the acceptability of this process.

Results

hundred patients (Mean age 75 years) were recruited. Most sarcopenia and frailty assessments were quick with complete data collection and were acceptable to patients and staff. Sarcopenia was identified among 4–39% participants depending on the tool and frailty among 9–25%. Both conditions were more common among men than women with all tools. The SARC-F and PRISMA-7 had the best sensitivity (100 and 93%, respectively) and specificity (96 and 87%). CGA among 80% of referred participants led to three interventions per participant (e.g. medication changes and investigations).

Conclusion

SARC-F and PRISMA-7 are recommended for use in fracture clinics to screen for sarcopenia and frailty.
Multitask brain network reconfiguration is inversely associated with human intelligence
Authors: Thiele Jonas A , Faskowitz Joshua , Sporns Olaf , Hilger Kirsten
Published: November 2021

Intelligence describes the general cognitive ability level of a person. It is one of the most fundamental concepts in psychological science and is crucial for the effective adaption of behavior to varying environmental demands. Changing external task demands have been shown to induce reconfiguration of functional brain networks. However, whether neural reconfiguration between different tasks is associated with intelligence has not yet been investigated. We used functional magnetic resonance imaging data from 812 subjects to show that higher scores of general intelligence are related to less brain network reconfiguration between resting state and seven different task states as well as to network reconfiguration between tasks. This association holds for all functional brain networks except the motor system and replicates in two independent samples (n = 138 and n = 184). Our findings suggest that the intrinsic network architecture of individuals with higher intelligence scores is closer to the network architecture as required by various cognitive demands. Multitask brain network reconfiguration may, therefore, represent a neural reflection of the behavioral positive manifold – the essence of the concept of general intelligence. Finally, our results support neural efficiency theories of cognitive ability and reveal insights into human intelligence as an emergent property from a distributed multitask brain network.
Cost-effectiveness of Check It: A Novel Community-Based Chlamydia Screening and Expedited Treatment Program for Young Black Men
Authors: Stoecker Charles , Monnette Alisha , Qu Zhuolin , Schmidt Norine , Craig-Kuhn Megan Clare , Kissinger Patricia J
Published: November 2021

Background

We assessed the cost-effectiveness of the Check It program, a novel community-based chlamydia screening and expedited partner treatment program for young Black men conducted in New Orleans since 2017.

Methods

We implemented a probabilistic cost-effectiveness model using a synthetic cohort of 16 181 men and 13 419 women intended to simulate the size of the Black, sexually active population in New Orleans ages 15–24 years.

Results

The Check It program cost $196 838 (95% confidence interval [CI]: $117 320–$287 555) to implement, saved 10.2 quality-adjusted life-years (QALYs; 95% CI: 7.7–12.7 QALYs), and saved $140 950 (95% CI: −$197 018 to −$105 620) in medical costs per year. The program cost $5468 (95% CI: cost saving, $16 717) per QALY gained. All iterations of the probabilistic model returned cost-effectiveness ratios less than $50 000 per QALY gained.

Conclusions

The Check It program (a bundled seek, test, and treat chlamydia prevention program for young Black men) is cost-effective under base case assumptions. Communities where Chlamydia trachomatis rates have not declined could consider implementing a similar program.
Phenotyping of Acute and Persistent Coronavirus Disease 2019 Features in the Outpatient Setting: Exploratory Analysis of an International Cross-sectional Online Survey
Authors: Sahanic Sabina , Tymoszuk Piotr , Ausserhofer Dietmar , Rass Verena , Pizzini Alex , Nordmeyer Goetz , Hüfner Katharina , Kurz Katharina , Weber Paulina Maria , Sonnweber Thomas , Boehm Anna , Aichner Magdalena , Cima Katharina , Boeckle Barbara , Holzner Bernhard , Rumpold Gerhard , Puelacher Christoph , Kiechl Stefan , Huber Andreas , Wiedermann Christian J , Sperner-Unterweger Barbara , Tancevski Ivan , Bellmann-Weiler Rosa , Bachler Herbert , Piccoliori Giuliano , Helbok Raimund , Weiss Guenter , Loeffler-Ragg Judith
Published: November 2021

Background

Long COVID, defined as the presence of coronavirus disease 2019 (COVID-19) symptoms ≥28 days after clinical onset, is an emerging challenge to healthcare systems. The objective of the current study was to explore recovery phenotypes in nonhospitalized individuals with COVID-19.

Methods

A dual cohort, online survey study was conducted between September 2020 and July 2021 in the neighboring European regions Tyrol (TY; Austria, n = 1157) and South Tyrol (STY; Italy, n = 893). Data were collected on demographics, comorbid conditions, COVID-19 symptoms, and recovery in adult outpatients. Phenotypes of acute COVID-19, postacute sequelae, and risk of protracted recovery were explored using semi-supervised clustering and multiparameter least absolute shrinkage and selection operator (LASSO) modeling.

Results

Participants in the study cohorts were predominantly working age (median age [interquartile range], 43 [31–53] years] for TY and 45 [35–55] years] for STY) and female (65.1% in TY and 68.3% in STY). Nearly half (47.6% in TY and 49.3% in STY) reported symptom persistence beyond 28 days. Two acute COVID-19 phenotypes were discerned: the nonspecific infection phenotype and the multiorgan phenotype (MOP). Acute MOP symptoms encompassing multiple neurological, cardiopulmonary, gastrointestinal, and dermatological symptoms were linked to elevated risk of protracted recovery. The major subset of individuals with long COVID (49.3% in TY; 55.6% in STY) displayed no persistent hyposmia or hypogeusia but high counts of postacute MOP symptoms and poor self-reported physical recovery.

Conclusions

The results of our 2-cohort analysis delineated phenotypic diversity of acute and postacute COVID-19 manifestations in home-isolated patients, which must be considered in predicting protracted convalescence and allocating medical resources.
Maintenance of Measles Elimination Status in the United States for 20 Years Despite Increasing Challenges
Authors: Mathis Adria D , Clemmons Nakia S , Redd Susan B , Pham Huong , Leung Jessica , Wharton Adam K , Anderson Raydel , McNall Rebecca J , Rausch-Phung Elizabeth , Rosen Jennifer B , Blog Debra , Zucker Jane R , Bankamp Bettina , Rota Paul A , Patel Manisha , Gastañaduy Paul A
Published: November 2021

Background

Measles elimination (interruption of endemic measles virus transmission) in the United States was declared in 2000; however, the number of cases and outbreaks have increased in recent years. We characterized the epidemiology of measles outbreaks and measles transmission patterns after elimination to identify potential gaps in the US measles control program.

Methods

We analyzed national measles notification data from 1 January 2001 to 31 December 2019. We defined measles infection clusters as single cases (isolated cases not linked to additional cases), 2-case clusters, or outbreaks with ≥3 linked cases. We calculated the effective reproduction number (R) to assess changes in transmissibility and reviewed molecular epidemiology data.

Results

During 2001–2019, a total of 3873 measles cases, including 747 international importations, were reported in the United States; 29% of importations were associated with outbreaks. Among 871 clusters, 69% were single cases and 72% had no spread. Larger and longer clusters were reported since 2013, including 7 outbreaks with >50 cases lasting >2 months, 5 of which occurred in known underimmunized, close-knit communities. No measles lineage circulated in a single transmission chain for >12 months. Higher estimates of R were noted in recent years, although R remained below the epidemic threshold of 1.

Conclusions

Current epidemiology continues to support the interruption of endemic measles virus transmission in the United States. However, larger and longer outbreaks in recent postelimination years and emerging trends of increased transmission in underimmunized communities emphasize the need for targeted approaches to close existing immunity gaps and maintain measles elimination.
The Carminows and Their Arms: History, Heraldry and Myth in Late Medieval and Early Modern Cornwall
Authors: Saul Nigel
Published: November 2021

At the beginning of the eighteenth century, the Cornish antiquary William Hals recorded a story etched in the Carminow family’s memory which recalled that one of their fourteenth-century forebears had been challenged by Richard, Lord Scrope over his right to the arms Azure, a bend or. The story built on references in the Scrope–Grosvenor hearings in the Court of Chivalry in the 1380s to ‘one Carminow’, actually Thomas Carminow, who had himself mounted a challenge to Scrope in the course of Edward III’s expedition to France in 1359–60. The article examines the justifications that Carminow is reported to have offered for his use of the arms, which he claimed his family had borne since the time of King Arthur, and then considers the reworking of the story in the late sixteenth century, when the changing circumstances of the family required it to be retold in a new form.
Functional analysis of Ost3p and Ost6p containing yeast oligosaccharyltransferases
Authors: Neuhaus Julia D , Wild Rebekka , Eyring Jillianne , Irobalieva Rossitza N , Kowal Julia , Lin Chia-wei , Locher Kaspar P , Aebi Markus
Published: November 2021

The oligosaccharyltransferase (OST) is the central enzyme in the N-glycosylation pathway. It transfers a defined oligosaccharide from a lipid-linker onto the asparagine side chain of proteins. The yeast OST consists of eight subunits and exists in two catalytically distinct isoforms that differ in one subunit, Ost3p or Ost6p. The cryo-electron microscopy structure of the Ost6p containing complex was found to be highly similar to the Ost3p containing OST. OST enzymes with altered Ost3p/Ost6p subunits were generated and functionally analyzed. The three C-terminal transmembrane helices were responsible for the higher turnover-rate of the Ost3p vs. the Ost6p containing enzyme in vitro and the more severe hypoglycosylation in Ost3p lacking strains in vivo. Glycosylation of specific OST target sites required the N-terminal thioredoxin domain of Ost3p or Ost6p. This Ost3p/Ost6p dependence was glycosylation site but not protein specific. We concluded that the Ost3p/Ost6p subunits modulate the catalytic activity of OST and provide additional specificity for OST substrate recognition.
Cell wall modifications by α-XYLOSIDASE1 are required for control of seed and fruit size in Arabidopsis
Authors: Di Marzo Maurizio , Viana Vívian Ebeling , Banfi Camilla , Cassina Valeria , Corti Roberta , Herrera-Ubaldo Humberto , Babolin Nicola , Guazzotti Andrea , Kiegle Edward , Gregis Veronica , de Folter Stefan , Sampedro Javier , Mantegazza Francesco , Colombo Lucia , Ezquer Ignacio
Published: November 2021

Cell wall modifications are of pivotal importance during plant development. Among cell wall components, xyloglucans are the major hemicellulose polysaccharide in primary cell walls of dicots and non-graminaceous monocots. They can connect the cellulose microfibril surface to affect cell wall mechanical properties. Changes in xyloglucan structure are known to play an important role in regulating cell growth. Therefore, the degradation of xyloglucan is an important modification that alters the cell wall. The α-XYLOSIDASE1 (XYL1) gene encodes the only α-xylosidase acting on xyloglucans in Arabidopsis thaliana. Here, we showed that mutation of XYL1 strongly influences seed size, seed germination, and fruit elongation. We found that the expression of XYL1 is directly regulated in developing seeds and fruit by the MADS-box transcription factor SEEDSTICK. We demonstrated that XYL1 complements the stk smaller seed phenotype. Finally, by atomic force microscopy, we investigated the role of XYL1 activity in maintaining cell stiffness and growth, confirming the importance of cell wall modulation in shaping organs.
Differences in star formation activity between tidally triggered and isolated bars: a case study of NGC 4303 and NGC 3627
Authors: Iles Elizabeth J , Pettitt Alex R , Okamoto Takashi
Published: November 2021

Galactic bars are important drivers of galactic evolution, and yet how they impact the interstellar medium and correspondingly star formation, remains unclear. We present simulation results for two barred galaxies with different formation mechanisms, bars formed in isolation or via a tidal interaction, to consider the spatially and temporally varying trends of star formation. We focus on the early (<1 Gyr) epoch of bar formation so that the interaction is clearly identifiable. The nearby NGC 4303 (isolated) and NGC 3627 (interaction history) are selected as observational analogues to tailor these simulations. Regardless of formation mechanism, both models show similar internal dynamical features, although the interaction appears to promote bar-arm disconnection in the outer disc velocity structure. Both bars trigger similar boosts in star formation (79 per cent; 66 per cent), while the interaction also triggers an earlier 31 per cent burst. Significant morphological dependence is observed in the relation between surface gas and star formation rate. In both cases, the bar component is notably steepest; the arm is similar to the overall disc average; and the interarm clearly the shallowest. A distinguishable feature of the tidal disc is the presence of moderately dense, inefficiently star-forming gas mostly confined to tidal debris outside the optical disc. The tidal disc also exhibits a unique trend of radially increasing star formation efficiency and a clear dearth of star formation which persists along the bar between the centre and bar ends. These are potential signatures for identifying a barred system post-interaction.
The Jodrell bank glitch catalogue: 106 new rotational glitches in 70 pulsars
Authors: Basu A , Shaw B , Antonopoulou D , Keith M J , Lyne A G , Mickaliger M B , Stappers B W , Weltevrede P , Jordan C A
Published: November 2021

Pulsar glitches are rapid spin-up events that occur in the rotation of neutron stars, providing a valuable probe into the physics of the interiors of these objects. Long-term monitoring of a large number of pulsars facilitates the detection of glitches and the robust measurements of their parameters. The Jodrell Bank pulsar timing programme regularly monitors more than 800 radio pulsars and has accrued, in some cases, over 50 yr of timing history on individual objects. In this paper, we present 106 new glitches in 70 radio pulsars as observed up to the end of 2018. For 70 per cent of these pulsars, the event we report is its only known glitch. For each new glitch, we provide measurements of its epoch, amplitude, and any detected changes to the spin-down rate of the star. Combining these new glitches with those listed in the Jodrell Bank glitch catalogue, we analyse a total sample of 543 glitches in 178 pulsars. We model the distribution of glitch amplitudes and spin-down rate changes using a mixture of two Gaussian components. We corroborate the known dependence of glitch rate and activity on pulsar spin-down rates and characteristic ages, and show that younger pulsars tend to exhibit larger glitches. Pulsars with spin-down rates between 10−14 and 10−10.5 Hz s−1 show a mean reversal of 1.8 per cent of their spin-down as a consequence of glitches. Our results are qualitatively consistent with the superfluid vortex unpinning models of pulsar glitches.
A decade of joint MOJAVE–Fermi AGN monitoring: localization of the gamma-ray emission region
Authors: Kramarenko I G , Pushkarev A B , Kovalev Y Y , Lister M L , Hovatta T , Savolainen T
Published: November 2021

Within the MOJAVE VLBA programme (Monitoring of Jets in AGN with VLBA Experiments), we have accumulated observational data at 15 GHz for hundreds of jets in gamma-ray bright active galactic nuclei since the beginning of the Fermi scientific observations in 2008 August. We investigated a time delay between the flux density of AGN parsec-scale radio emission at 15 GHz and 0.1–300 GeV Fermi LAT photon flux, taken from constructed light curves using weekly and adaptive binning. The correlation analysis shows that radio is lagging gamma-ray radiation by up to 8 months in the observer’s frame, while in the source frame, the typical delay is about 2–3 months. If the jet radio emission, excluding the opaque core, is considered, significant correlation is found at greater time lags. We supplement these results with VLBI kinematics and core shift data to conclude that the dominant high-energy production zone is typically located at a distance of several parsecs from the central nucleus. We also found that quasars have on average more significant correlation peak, more distant gamma-ray emission region from the central engine and shorter variability time-scale compared to those of BL Lacertae objects.