bluuebunny/crossref_metadata_2025 huggingface dataset:
Theoretical and numerical perspectives on cosmic distance averages
Authors: Breton Michel-Andrès , Fleury Pierre
Published: August 2021

The interpretation of cosmological observations relies on a notion of an average Universe, which is usually considered as the homogeneous and isotropic Friedmann-Lemaître-Robertson-Walker (FLRW) model. However, inhomogeneities may statistically bias the observational averages with respect to FLRW, notably for distance measurements, due to a number of effects such as gravitational lensing and redshift perturbations. In this article, we review the main known theoretical results on average distance measures in cosmology, based on second-order perturbation theory, and we fill in some of their gaps. We then comprehensively test these theoretical predictions against ray tracing in a high-resolution dark-matter N-body simulation. This method allows us to describe the effect of small-scale inhomogeneities deep into the non-linear regime of structure formation on light propagation up to z = 10. We find that numerical results are in remarkably good agreement with theoretical predictions in the limit of super-sample variance. No unexpectedly large bias originates from very small scales, whose effect is fully encoded in the non-linear power spectrum. Specifically, the directional average of the inverse amplification and the source-averaged amplification are compatible with unity; the change in area of surfaces of constant cosmic time is compatible with zero; the biases on other distance measures, which can reach slightly less than 1% at high redshift, are well understood. As a side product, we also confront the predictions of the recent finite-beam formalism with numerical data and find excellent agreement.
Large-amplitude longitudinal oscillations in solar prominences simulated with different resolutions
Authors: Liakh V. , Luna M. , Khomenko E.
Published: August 2021

Context. Large-amplitude longitudinal oscillations (LALOs) in solar prominences have been widely studied in recent decades. However, their damping and amplification mechanisms are not well understood.

Aims. In this study, we investigate the attenuation and amplification of LALOs using high-resolution numerical simulations with progressively increasing spatial resolutions.

Methods. We performed time-dependent numerical simulations of LALOs using the 2D magnetic configuration that contains a dipped region. After the prominence mass loading in the magnetic dips, we triggered LALOs by perturbing the prominence mass along the magnetic field. We performed the experiments with four values of spatial resolution.

Results. In the simulations with the highest resolution, the period shows good agreement with the pendulum model. The convergence experiment revealed that the damping time saturates at the bottom prominence region with increasing resolution, indicating the existence of a physical reason for the damping of oscillations. At the prominence top, the oscillations are amplified during the first minutes and are then slowly attenuated. The characteristic time suggests more significant amplification in the experiments with the highest spatial resolution. The analysis revealed that the energy exchange between the bottom and top prominence regions is responsible for the attenuation and amplification of LALOs.

Conclusions. High-resolution experiments are crucial when studying the periods and the damping mechanism of LALOs. The period agrees with the pendulum model only when using a sufficiently high spatial resolution. The results suggest that numerical diffusion in simulations with insufficient spatial resolution can hide important physical mechanisms, such as amplification of oscillations.
Laser infrarouge à base de semi-conducteurs de la filière silicium
Authors: El Kurdi Moustafa , Sakat Emilie , Hartmann Jean-Michel , Reboud Vincent , Chelnokov Alexei , Pauc Nicolas , Calvo Vincent , Boucaud Philippe , Bœuf Fréderic
Published: August 2021

Nous présentons les récents développements scientifiques et techniques liés aux sources lasers infrarouges en micro-cavités à base d’alliages germanium-étain (GeSn). Ces alliages sont des matériaux semi-conducteurs de la filière silicium compatibles avec les procédés de fabrication bas coût de l’industrie de la micro-électronique. Un des enjeux est d’obtenir un alignement direct de la structure de bande électronique avec ces éléments de la colonne IV.
Prävention nicht übertragbarer chronischer Erkrankungen durch „gesunde“ Ernährung
Authors: Bosy-Westphal Anja , Müller Manfred J.
Published: August 2021

Übergewicht betrifft mehr als 50 % der Erwachsenen in Deutschland, 20 Millionen Menschen sind adipös, zwischen 10 und 30 % haben Stoffwechsel- und Herz-Kreislauf-Erkrankungen. Diese nicht übertragbaren Krankheiten („non-communicable diseases“, NCD) sind hochanteilig durch eine der Gesundheit abträgliche Ernährung verursacht und unnötig. Da die Produktion von Lebensmitteln und auch deren Konsum eng mit den aktuellen Problemen von Umwelt, Klima und ungebremstem ökonomischem Wachstum verknüpft sind, können nachhaltig wirksame Maßnahmen der Prävention von NCD nur in größeren Kontexten realisiert werden. Aus dieser Sicht ist es an uns Ärzten, sowohl die Patienten ernährungsmedizinisch angemessen zu behandeln als auch den notwendigen gesellschaftlichen Wandel zum Erhalt der Gesundheit von Mensch und Umwelt mitzugestalten.
Hepatic Meteorin-like and Krüppel-like Factor 3 are Associated with Weight Loss and Liver Injury
Authors: Grander Christoph , Grabherr Felix , Enrich Barbara , Meyer Moritz , Mayr Lisa , Schwärzler Julian , Pedrini Alisa , Effenberger Maria , Adolph Timon E. , Tilg Herbert
Published: August 2021

Objective Laparoscopic adjustable gastric banding (LAGB) was found to be effective in reducing body weight and improving insulin resistance in patients with obesity and non-alcoholic fatty liver disease (NAFLD). The adipokine/myokine meteorin-like (METNRL) is an important regulator of whole-body energy expenditure. Krüppel-like factor 3 (KLF3), a regulator of METRNL expression in eosinophils, inhibits the beiging of adipose tissue in mice and therefore regulates adipose tissue development.

Methods Thirty-three obese patients undergoing LAGB were included in the study. The hepatic and adipose tissue expression of METNRL and KLF3 was determined before (t0) and 6 months after (t6) LABG. The human liver cancer cell line (HepG2) was stimulated with cytokines and fatty acids and METNRL and KLF3 expressions were analyzed.

Results LAGB-associated weight loss was correlated with decreased hepatic METNRL expression. The expression of METNRL and KLF3 in hepatic-and adipose tissues correlated before and after LAGB. Individuals with augmented LAGB-induced weight loss (>20 kg) showed lower hepatic METNRL and KLF3 expression before and after LAGB than patients with <20 kg weight loss. METNRL and KLF3 levels were higher in patients with higher NAFLD activity scores. HepG2 stimulation with interleukin-1β, tumor necrosis factor-α, palmitic acid but not interleukin-6, oleic acid, or lipopolysaccharide, induced the expression of one or both investigated adipokines.

Conclusions The novel description of METRNL and KLF3 as hepatokines could pave the way to target their production and/or signaling in obesity, NAFLD, and related disorders. Both proteins may act as possible biomarkers to estimate weight loss after bariatric surgery.
Evaluation of Electronic Health Record-Based Suicide Risk Prediction Models on Contemporary Data
Authors: Walker Rod L. , Shortreed Susan M. , Ziebell Rebecca A. , Johnson Eric , Boggs Jennifer M. , Lynch Frances L. , Daida Yihe G. , Ahmedani Brian K. , Rossom Rebecca , Coleman Karen J. , Simon Gregory E.
Published: August 2021

Background Suicide risk prediction models have been developed by using information from patients' electronic health records (EHR), but the time elapsed between model development and health system implementation is often substantial. Temporal changes in health systems and EHR coding practices necessitate the evaluation of such models in more contemporary data.

Objectives A set of published suicide risk prediction models developed by using EHR data from 2009 to 2015 across seven health systems reported c-statistics of 0.85 for suicide attempt and 0.83 to 0.86 for suicide death. Our objective was to evaluate these models' performance with contemporary data (2014–2017) from these systems.

Methods We evaluated performance using mental health visits (6,832,439 to mental health specialty providers and 3,987,078 to general medical providers) from 2014 to 2017 made by 1,799,765 patients aged 13+ across the health systems. No visits in our evaluation were used in the previous model development. Outcomes were suicide attempt (health system records) and suicide death (state death certificates) within 90 days following a visit. We assessed calibration and computed c-statistics with 95% confidence intervals (CI) and cut-point specific estimates of sensitivity, specificity, and positive/negative predictive value.

Results Models were well calibrated; 46% of suicide attempts and 35% of suicide deaths in the mental health specialty sample were preceded by a visit (within 90 days) with a risk score in the top 5%. In the general medical sample, 53% of attempts and 35% of deaths were preceded by such a visit. Among these two samples, respectively, c-statistics were 0.862 (95% CI: 0.860–0.864) and 0.864 (95% CI: 0.860–0.869) for suicide attempt, and 0.806 (95% CI: 0.790–0.822) and 0.804 (95% CI: 0.782–0.829) for suicide death.

Conclusion Performance of the risk prediction models in this contemporary sample was similar to historical estimates for suicide attempt but modestly lower for suicide death. These published models can inform clinical practice and patient care today.
Treatment Outcomes for Osteoradionecrosis of the Central Skull Base: A Systematic Review
Authors: Shaikh Noah , Makary Chadi A. , Ryan Lindsey , Reyes Camilo
Published: August 2021

Objective Osteoradionecrosis (ORN) of the skull base can have catastrophic consequences if not detected early and managed appropriately. This is a systematic review of the different treatment modalities for skull base ORN and their outcomes.

Study Design This study is a systematic review.

Materials and Methods Two researchers extracted information including patient population, surgical technique, outcomes of interest, and study design. A computerized search of Medline, Embase, and the Cochrane library (January 1990–June 2020) looked for several papers on the subject of skull base ORN.

Results A total of 29 studies had met inclusion criteria, including data from 333 patients. Nasopharyngeal carcinoma was the most common primary tumor (85%). Average age at diagnosis of ORN was 55.9 years (range = 15–80 years) and 72.3% of patients were males. The average time to diagnosis of ORN after radiation therapy was 77 months with an average radiation dose of 76.2 Gy (range = 46–202 Gy). Nighty-eight patients (29.4%) also had chemotherapy as part of their treatment regimen. Although all parts of the central skull base were reported to be involved, the clivus and sphenoid bone were the most commonly reported subsites. Trial of medical treatment had a success rate of 41.1%. About 66% of patients needed surgical treatment, either primarily or after failing medical treatment. Success rate was 77.3%. Overall, the surgical treatment was superior to medical treatment (p < 0.0001).

Conclusion ORN is a rare complication of the treatment of skull base tumors. Most cases require surgical treatment, including endoscopic debridement or free flap reconstruction, which has a high success rate.

Level of Evidence Level 3 evidence as a systematic review of case studies, case reports, retrospective, and prospective trials with no blinding or controls.
No One Left Behind: Using Mixed-Methods Research to Identify and Learn from Socially Marginalised Adolescents in Low- and Middle-Income Countries
Authors: Baird Sarah , Camfield Laura , Haque Ashraful , Jones Nicola , Al Masri Anas , Pincock Kate , Puri Mahesh C.
Published: August 2021

This article describes the mixed-methods approach used by the Gender and Adolescence: Global Evidence (GAGE) research programme. It discusses how qualitative and quantitative methods can be used both in isolation and combined to learn about the lives of adolescents in low- and middle-income countries (LMICs), focusing on the methodological and ethical approaches used to reach socially marginalised adolescents (including adolescents with disabilities, adolescents not in school, adolescent refugees, adolescents living in urban slums, adolescents who married as children, and adolescent mothers). We reflect on the implementation of the GAGE conceptual framework, discussing its strengths and weaknesses, and the challenges to promoting inclusive and genuinely mixed-methods research practices. While these methods have been adapted in the countries where research was undertaken, the conceptual framework provides a common methodological approach, utilising an intersectional lens. We show how mixed-methods approaches can contribute to the knowledge base on research with socially marginalised adolescent girls and boys globally, serving as an important resource for future research with young people in LMICs.
On the spontaneous beauty of cities: neither design nor chaos
Authors: Cozzolino Stefano
Published: August 2021

A clear bridge connecting the theory of spontaneous order and the issue of beauty in and for cities has not yet been developed. After a general exploration of the concept of beauty, this article builds an alternative idea of beauty, namely, beauty as spontaneity. In particular, it argues that beauty in the urban realm greatly depends on forms and orders that can hardly be comprehensively designed but rather emerge as the result of the freedom granted to multiple urban agents to express themselves in space. In this article the works of Jacobs and Romano are analysed and explored. Starting from some of their main ideas, the paper suggests certain planning and design tactics to nurture this kind of beauty and provides some essential ethical principles.
Influence of thermal stratification on vertical natural convection—Experimental investigations on the example of thermal energy storage systems
Authors: Otto H. , Cierpka C.
Published: August 2021

Stratified thermal energy storages (TESs) are a promising solution for the large-scale energy storage problem of surplus renewable energy. Recent studies have shown parasitic convection occurring in near-wall regions inside such storage tanks, decreasing the working fluid's thermal stratification and reducing their exergy efficiency. This paper presents an experimental investigation of vertical convective flows in thermally stratified environments to complement the theoretical studies in this field. Specifically, we consider natural convection within a stratified laminar flow driven not by active heating but by the temperature gradient along a vertical wall, as is the case in real TES systems. The insights gained into the fundamental physical mechanisms of stratified vertical convection can promote efficiency improvements in TES systems. Therefore, we combine multiple particle image velocimetry and temperature measurements at different heights and thus obtain high-resolution vector fields of the entire wall jet flow and vertical temperature profiles for a TES model experiment. We appropriately modify scaling arguments found in the literature to develop a theory specifically suited to the experimental setup. The experimental data agree well with the modified theory. The results show two laminar counter-directed jets next to the vertical sidewall. In regions with high temperature gradients, the wall jets slow down, and flow reversals occur next to them. Moreover, the wall jets are asymmetric due to temperature-dependent fluid properties in conjunction with the ambient fluid stratification. In the stratification's upper, hot part, the wall jet is thinner and faster than the bottom jet in the cold region.
Gait phase detection based on inertial measurement unit and force-sensitive resistors embedded in a shoe
Authors: Liu Xianwen , Zhang Shimin , Yao Benchun , Yu Yang , Wang Yusong , Fan Jinchao
Published: August 2021

This study proposes a system to detect the phases of gait. It consists of an intelligent shoe equipped with an inertial measurement unit (IMU) and force-sensitive resistors (FSRs), and it uses a compound method to recognize gait. The continuous wavelet transform is applied according to accelerations obtained via the IMU to identify heel strike and toe-off events. These events are used to calculate the pressure threshold and proportional factor via the Lopez–Meyer (LM) method by using minimal leave-one-out for training and validation. The LM method can identify the entire sub-phase of the stance of the gait based on ground contact forces measured by using the FSRs and rules of gait event detection. The proposed system was tested on five healthy volunteers who used the intelligent shoe. The results show that it can detect all sub-phases of the gait with an overall accuracy (96%) higher than the LM method. The proportional factor was adaptable to variable body weights, and the reported average errors of competing systems in the literature significantly exceeded the average variation of the proposed system for all phases of gait. The range of errors in the swing phase and sub-phases of stance was also acceptable for application purposes. When the size of the subject’s foot was close to that of the intelligent shoe, the error between normative data and phases of gait identified by the detection system was minimal. Furthermore, the proposed system detected abnormalities in the gait circle, and thus, it can be used to monitor the walking activity and measure the motor recovery.
Energy exchange in two-fraction systems of charged dust particles
Authors: Vaulina O. S. , Kaufman S. V. , Lisin E. A.
Published: August 2021

A study of the processes of redistribution of stochastic kinetic energy between two fractions of dust particles with different sizes and temperatures, as well as its redistribution by degrees of freedom, is presented for conditions close to the conditions of experiments in gas-discharge plasma. The numerical simulation was carried out for two-layer ensembles and bulk clouds of charged particles in the gravity field, and for two-dimensional structures formed in the external electric fields under the influence of forces proportional to the square of dust radius. The influence of high temperatures on the energy balance in the analyzed systems is considered. A semiempirical approximation is proposed, which well describes the energy exchange in all considered cases.
Evaluation of linearity at 30 GHz for N-polar GaN deep recess transistors with 10.3 W/mm of output power and 47.4% PAE
Authors: Romanczyk Brian , Guidry Matthew , Zheng Xun , Shrestha Pawana , Li Haoran , Ahmadi Elaheh , Keller Stacia , Mishra Umesh K.
Published: August 2021

The advantage of GaN is the capability of producing amplifiers with high output power and efficiency. At microwave frequencies, this performance has been achieved; however, when transitioning device design into mm-wave frequencies, the output power and efficiency of GaN HEMTs decrease. Traditionally, the approach taken to develop Ka-band (30–40 GHz) GaN devices has been to modify a device designed for a lower frequency. By contrast, this work modified a N-polar GaN deep recess HEMT developed for W-band power performance (94 GHz), for improved performance in the Ka-band. In this Letter, we first report on improvement in the 30 GHz continuous-wave (CW) power density through modification of the W-band device with the demonstration of 10.3 W/mm at 47.4% power-added efficiency (PAE). We then report on the two-tone linearity performance of the device when measured under the same bias and matching conditions. While the evaluation of GaN HEMTs has traditionally focused on the use of one-tone CW power measurements, with the increasing adoption of GaN transistors into communication systems, such as mm-wave 5 G cellular communication, simply demonstrating high power density and efficiency does not provide a sufficient understanding of the device as high linearity is required to transmit data using complex modulation schemes. Under two-tone stimulus, the device demonstrates an OIP3 to PDC ratio greater than 6.7 dB and a C/IM3 ratio of greater than 37 dBc under backoff conditions greater than 10 dB from the peak one-tone PAE.
Active orbital preservation for multiconfigurational self-consistent field
Authors: Paz Amiel S. P. , Baleeva Nadezhda S. , Glover William J.
Published: August 2021

We introduce Active Orbital Preservation for Multiconfigurational Self-Consistent Field (AOP-MCSCF), an automated approach to improving the consistency of active space orbitals over multiple molecular configurations. Our approach is based on maximum overlap with a reference set of active space orbitals taken from a single geometry of a chromophore in the gas phase and can be used to automatically preserve the appropriate orbitals of the chromophore across multiple thermally sampled configurations, even when the chromophore is solvated by quantum-mechanically treated water molecules. In particular, using the singular value decomposition of a Molecular Orbital (MO) overlap matrix between the system and reference, we rotate the MOs of the system to align with the reference active space orbitals and use the resulting rotated orbitals as an initial guess to a MCSCF calculation. We demonstrate the approach on aqueous p-hydroxybenzylidene-imidazolinone (HBI) and find that AOP-MCSCF converges to the “correct” orbitals for over 90% of 3000 thermally sampled configurations. In addition, we compute the linear absorption spectrum and find excellent agreement with new experimental measurements up to 5.4 eV (230 nm). We show that electrostatic contributions to the solvation energy of HBI largely explain the observed state-dependent solvatochromism.
Dynamic iterative approximate deconvolution models for large-eddy simulation of turbulence
Authors: Yuan Zelong , Wang Yunpeng , Xie Chenyue , Wang Jianchun
Published: August 2021

Dynamic iterative approximate deconvolution (DIAD) models with Galilean invariance are developed for subgrid-scale (SGS) stress in the large-eddy simulation (LES) of turbulence. The DIAD models recover the unfiltered variables using the filtered variables at neighboring points and iteratively update model coefficients without any a priori knowledge of direct numerical simulation (DNS) data. The a priori analysis indicates that the DIAD models reconstruct the unclosed SGS stress much better than the classical velocity gradient model and approximate deconvolution model with different filter scales ranging from viscous to inertial regions. We also propose a small-scale eddy viscosity (SSEV) model as an artificial dissipation to suppress the numerical instability based on a scale-similarity-based dynamic method without affecting large-scale flow structures. The SSEV model can predict a velocity spectrum very close to that of DNS data, similar to the traditional implicit large-eddy simulation. In the a posteriori testing, the SSEV-enhanced DIAD model is superior to the SSEV model, dynamic Smagorinsky model, and dynamic mixed model, which predicts a variety of statistics and instantaneous spatial structures of turbulence much closer to those of filtered DNS data without significantly increasing the computational cost. The types of explicit filters, local spatial averaging methods, and initial conditions do not significantly affect the accuracy of DIAD models. We further successfully apply DIAD models to the homogeneous shear turbulence. These results illustrate that the current SSEV-enhanced DIAD approach is promising in the development of advanced SGS models in the LES of turbulence.
Cu-ion-actuated three-terminal neuromorphic synaptic devices based on binary metal-oxide electrolyte and channel
Authors: Kang Heebum , Woo Jiyong
Published: August 2021

An analogous change in lateral channel current from source to drain in three-terminal synaptic devices actuated by mobile ions vertically provided from a gate can enhance neuromorphic computing performances. We demonstrate a gradually tuned channel current in a fully complementary metal–oxide–semiconductor compatible HfOx/WOx stack with Cu ions. By examining each layer in the three-terminal device, such as the channel, electrolyte, and mobile ion supplier, we identify which device structure can modulate the channel current effectively using mobile ions. Our findings reveal that the gate-tunable channel current response can be solely achieved when the Cu ions are not locally formed but migrate throughout the HfOx electrolyte. The linear dependence of the analog current operation on the channel width further proves the area-switching mechanism. The importance of ion movement can be indirectly verified from the uncontrollable channel currents using either Ag ions with faster mobility than Cu ions or a local path is created because of the thinned HfOx electrolyte.
Linear unsaturated magnetoresistance in YSi single crystal
Authors: Saini Vikas , Sasmal Souvik , Kulkarni Ruta , Thamizhavel Arumugam
Published: August 2021

Linear magnetoresistance is a phenomenon observed in a few topological compounds originating from both classical and quantum phenomena. Here, we performed electrical transport measurements, in zero and applied magnetic fields, on the YSi single crystal along all three principal crystallographic directions of the orthorhombic crystal structure. For the J∥[001]; B∥[100] direction above ≈10 T, mobility fluctuations driven linear magnetoresistance is observed without any sign of saturation up to the 14 T magnetic field. Anisotropy in the Fermi surface is imminent from the angular dependence of the magnetoresistance. Kohler rule violation is observed in this system, and Hall data signify multiple charge carriers in YSi.
The influence of nonlinearities on jet noise modeling based on parabolized stability equation
Authors: Zhang Peng-Jun-Yi , Wan Zhen-Hua , Sun De-Jun
Published: August 2021

With the aid of a large eddy simulation (LES) model of a turbulent jet, we study the modeling of jet noise based on wavepackets by considering a certain degree of nonlinearity. Linear parabolized stability equations (PSEs) are utilized to solve the spatial evolution of wavepackets with the base flow obtained from the LES. The spectral proper orthogonal decomposition (SPOD) is performed to extract the most energetic coherent structures. Since the mean flow includes partial nonlinearity, improved agreement of hydrodynamic pressure fields between SPOD-filtered results and linear-PSE solutions is obtained in the near field. Deviations only occur when the coherent structures decay. Although linear-PSE solutions represent the near-field hydrodynamics reasonably, the far-field noise propagated from this linear model shows a large deviation from the LES results. Then, a small external harmonic forcing is added to the right-hand side of the PSE to mimic the effects of nonlinearity due to incoherent fluctuations on the late evolution of near-field wavepackets, and an adjoint approach is further utilized to search for optimal forcing distribution. Optimized forcing is mainly located near the critical layer; enhances the energy of wavepackets; and raises the sound radiation efficiency, but to a limited extent. Meanwhile, the coherence-matched PSE wavepacket is proposed to incorporate the coherence decay of wavepackets calculated based on LES. An improved agreement in far-field sound pressure levels for low-frequency components is achieved. In short, these findings all prove the vital role of nonlinearity in jet noise modeling, and the current modeling approaches have made some progress. However, a more physics-based and generalized nonlinear model is still required.
Parsing β-catenin’s cell adhesion and Wnt signaling functions in malignant mammary tumor progression
Authors: Buechel David , Sugiyama Nami , Rubinstein Natalia , Saxena Meera , Kalathur Ravi K. R. , Lüönd Fabiana , Vafaizadeh Vida , Valenta Tomas , Hausmann George , Cantù Claudio , Basler Konrad , Christofori Gerhard
Published: August 2021

Significance

Canonical, β-catenin–dependent Wnt signaling is well known to promote a variety of cancer types. However, the contribution of β-catenin’s cell adhesion function versus its transcriptional output to malignant tumor progression and metastasis has remained unexplored. We dissected β-catenin’s function in cell adhesion from its transcriptional output in Wnt signaling in the mouse mammary tumor virus (MMTV)–PyMT transgenic mouse model of metastatic breast cancer. We found that β-catenin’s dual functions are required for tumor cell survival. In contrast, its transcriptional activity is required for the regulation of epithelial–mesenchymal transition in vitro and metastasis formation in vivo. Altogether, the results delineate at a molecular and mechanistic level β-catenin’s contribution to malignant breast cancer progression.
Cooperative recruitment of RDR6 by SGS3 and SDE5 during small interfering RNA amplification in
Arabidopsis
Authors: Yoshikawa Manabu , Han Yong-Woon , Fujii Hirofumi , Aizawa Shu , Nishino Tatsuya , Ishikawa Masayuki
Published: August 2021

Significance

In plants, RNA-induced silencing complexes that contain 22-nucleotide small interfering RNA (siRNA) and Argonaute 1 protein induce siRNA amplification from their targets. In this pathway, double-stranded RNAs (dsRNAs) are synthesized by RNA-dependent RNA polymerase proteins, and the dsRNAs are processed into siRNAs by Dicer-like proteins, leading to amplification of siRNAs to targets. Because dsRNA formation from nontarget RNAs causes nonspecific siRNA production, this pathway needs to be strictly regulated. By using an in vitro siRNA amplification system, we demonstrate that RNA-dependent RNA polymerase proteins are specifically recruited to targets in coordination with two plant-specific proteins. Based on the results, we discuss how specificity of siRNA amplification is secured.
Genomic structural variants constrain and facilitate adaptation in natural populations of
Theobroma cacao
, the chocolate tree
Authors: Hämälä Tuomas , Wafula Eric K. , Guiltinan Mark J. , Ralph Paula E. , dePamphilis Claude W. , Tiffin Peter
Published: August 2021

Significance

Genomic structural variants (SVs) are frequent contributors to adaptation and speciation, but our understanding of their overall fitness consequences is limited, with data and analyses primarily available for humans and short-lived domesticated species. Here, we use 31 high-quality genome assemblies to study the evolutionary impact of SVs among natural populations of
Theobroma cacao
. We find that most SVs are deleterious and thus constrain adaptation. These detrimental effects likely arise as a direct result of impaired gene function and as an indirect result of suppressed recombination. Yet we detect several SVs that may contribute to local adaptation mainly through traits involved in pathogen resistance. Overall, we provide important insight into processes underlying the fitness effects of SVs in natural populations.
Optimized delay of the second COVID-19 vaccine dose reduces ICU admissions
Authors: Silva Paulo J. S. , Sagastizábal Claudia , Nonato Luís Gustavo , Struchiner Claudio José , Pereira Tiago
Published: August 2021

Significance

Shortages of COVID-19 vaccines hampered efforts to fight the current pandemic, leading experts to argue for delaying the second dose to provide earlier first-dose protection to twice as many people. We designed a model-based strategy for identifying the optimal second-dose delay using the hospitalization rate as the key metric. While epistemic uncertainties apply to our modeling, we found that the optimal delay was dependent on first-dose efficacy and vaccine mechanism of action. For infection-blocking vaccines, the second dose could be delayed

≥

8 weeks if the first-dose efficacy was

≥

50%. For symptom-alleviating vaccines, this delay duration is recommended if the first-dose efficacy was

≥

70%. These results suggest that delaying the second vaccine dose is a feasible option.
Cross-correlation analysis of X-ray photon correlation spectroscopy to extract rotational diffusion coefficients
Authors: Hu Zixi , Donatelli Jeffrey J. , Sethian James A.
Published: August 2021

Significance

X-ray photon correlation spectroscopy (XPCS) is a powerful technique that can probe a broad range of space and time scales and will become increasingly powerful due to coming advancements in coherence. Assessing translational and rotational diffusion is a key quantity in analyzing material structures and dynamics, with applications across molecular biology, drug discovery, and materials science. While methods for estimating translational diffusion coefficients from XPCS data are well-developed, there are no algorithms for measuring the rotational diffusion. Here, we present a mathematical formulation and algorithm based on angular-temporal cross-correlations for extracting this rotational information, providing tools for data analysis of XPCS. Although we focus on XPCS, the proposed method can be applied to other experimental techniques due to its generality.
Hepatic FGF21 preserves thermoregulation and cardiovascular function during bacterial inflammation
Authors: Huen Sarah C. , Wang Andrew , Feola Kyle , Desrouleaux Reina , Luan Harding H. , Hogg Richard , Zhang Cuiling , Zhang Qing-Jun , Liu Zhi-Ping , Medzhitov Ruslan
Published: August 2021

Sickness behaviors, including anorexia, are evolutionarily conserved responses to acute infections. Inflammation-induced anorexia causes dramatic metabolic changes, of which components critical to survival are unique depending on the type of inflammation. Glucose supplementation during the anorectic period induced by bacterial inflammation suppresses adaptive fasting metabolic pathways, including fibroblast growth factor 21 (FGF21), and decreases survival. Consistent with this observation, FGF21-deficient mice are more susceptible to mortality from endotoxemia and polybacterial peritonitis. Here, we report that increased circulating FGF21 during bacterial inflammation is hepatic derived and required for survival through the maintenance of thermogenesis, energy expenditure, and cardiac function. FGF21 signaling downstream of its obligate coreceptor, β-Klotho (KLB), is required in bacterial sepsis. However, FGF21 modulates thermogenesis and chronotropy independent of the adipose, forebrain, and hypothalamus, which are operative in cold adaptation, suggesting that in bacterial inflammation, either FGF21 signals through a novel, undescribed target tissue or concurrent signaling of multiple KLB-expressing tissues is required.
Ni self-diffusion in glass forming Pd–Ni–S melts
Authors: Wilden Johanna , Yang Fan , Günther Gerrit , Russina Margarita , Kuball Alexander , Busch Ralf , Meyer Andreas
Published: August 2021

The Ni self-diffusion in glass forming Pd40Ni40S20, Pd37Ni37S26 and Pd31Ni42S27 melts was probed by incoherent, quasielastic neutron scattering over a temperature range between 773 and 1023 K. The Ni self-diffusion coefficients are on a 10−10 m2 s−1–10−9 m2 s−1 scale and barely change with composition. Each composition exhibits an Arrhenius-type temperature dependence of the Ni self-diffusion coefficients, which results in activation energies ranging from E
A = 348 ± 16 meV for Pd40Ni40S20 to E
A = 387 ± 6 meV for Pd37Ni37S26. The structural relaxation shows a stretched exponential behavior even far above the liquidus temperatures. In addition, the viscosity of the Pd37Ni37S26 melt was measured under reduced gravity conditions. The diffusion calculated from the viscosity reveals a significant deviation from the measured Ni self-diffusion by a factor between 4 and 8. This may indicate a dynamic decoupling between the atoms within the Pd–Ni–S equilibrium melts.
Adiabatic edge-to-edge transformations in time-modulated elastic lattices and non-Hermitian shortcuts
Authors: Riva Emanuele , Castaldini Gianmaria , Braghin Francesco
Published: August 2021

The temporal modulation of a relevant parameter can be employed to induce modal transformations in Hermitian elastic lattices. When this is combined with a proper excitation mechanism, it allows to drive the energy transfer across the lattice with tunable propagation rates. Such a modal transformation, however, is limited by the adiabaticity of the process, which dictates an upper bound for the modulation speed. In this manuscript, we employ a non-Hermitian shortcut by way of a tailored gain and loss to violate the adiabatic limit and, therefore, to achieve superfast modal transformations. A quantitative condition for adiabaticity is firstly derived and numerically verified for a pair of weakly coupled time-dependent mechanical oscillators, which can be interpreted in the light of modal interaction between crossing states. It is shown that for sufficiently slow time-modulation, the elastic energy can be transferred from one oscillator to the other. A non-Hermitian shortcut is later induced to break the modal coupling and, therefore, to speed-up the modal transformation. The strategy is then generalized to elastic lattices supporting topological edge states. We show that the requirements for a complete edge-to-edge energy transfer are lifted from the adiabatic limit toward higher modulation velocities, opening up new opportunities in the context of wave manipulation and control.
Magnetoplasmon resonance in two-dimensional fluctuating superconductors
Authors: Sonowal K , Kovalev V M , Savenko I G
Published: August 2021

We develop a theory of the magnetoplasmon resonance (MPR) in two-dimensional superconductors in the fluctuating regime, where the temperature is slightly above the critical temperature of the superconducting transition. In this regime, unpaired electrons and fluctuating Cooper pairs coexist in the system and interact with each other via long-range Coulomb forces, forming a Bose–Fermi mixture. The sample is considered to be under the influence of an external time-dependent electromagnetic field with a frequency in sub-terahertz range and a permanent magnetic field. It is shown that the MPR of the system is strongly modified in the presence of superconducting fluctuations in the vicinity of the superconducting transition. In particular, the fluctuating Cooper pairs dramatically change the broadening of the MPR, which is reflected in the optical response of the system.
Characterizing the Zeeman slowing force for 40Ca19F molecules
Authors: Kaebert P , Stepanova M , Poll T , Petzold M , Xu S , Siercke M , Ospelkaus S
Published: August 2021

In this paper we investigate the feasibility of Zeeman slowing calcium monofluoride molecules originating from a cryogenic buffer gas cell. We measure the

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hyperfine spectrum of CaF in the Paschen–Back regime and find excellent agreement with theory. We then investigate the scattering rate of the molecules in a molecular Zeeman slower by illuminating them with light from a 10 mW broad repumper and a 10 mW multi-frequency slowing laser. By comparing our results to theory we can calculate the photon scattering rate at higher powers, leading to a force profile for Zeeman slowing. We show results from a simple 1D simulation demonstrating that this force is narrow enough in velocity space to lead to significant velocity compression, and slowing of the molecules to trappable velocities.
A theoretical investigation of the quarter-wavelength model-part 2: verification and extension
Authors: Liu Ying , Liu Yue , Drew Michael G B
Published: August 2021

The quarter-wavelength model states that the reflection of microwaves is minimized if the thickness of the film is mλ/4 where m is an odd integer and λ is the wavelength within the film . In part 1 of this work, published previously, it was shown that the theory behind this model is flawed and that it needs to be replaced using a wave superposition approach involving principles not beyond physics at college level. Through the verification of the results from formulae familiar to material scientists, it is shown here that many other concepts in current mainstream microwave absorption theory are used inappropriately including that reflection loss RL has been used to characterize microwave absorption from material instead of film and also that the results have been rationalized incorrectly by impedance matching theory. Impedance matching theory is developed from transmission-line theory for scattering parameter s

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but cannot be applied to RL which is an innate property only for metal-backed film.
Advances in prediction of tokamak experiments with theory-based models
Authors: Staebler G.M. , Knolker M. , Snyder P. , Angioni C. , Fable E. , Luda T. , Bourdelle C. , Garcia J. , Citrin J. , Marin M. , Kim H.-T. , Kinsey J. , Lee C.Y. , Na Yong-Su , Park J.M. , Rodriguez-Fernandez P. , Wu M.
Published: August 2021

The successful validation of theory-based models of transport, magnetohydrodynamic stability, heating and current drive, with tokamak measurements over the last 20 years, has laid the foundation for a new era where these models can be routinely used in a ‘predict first’ approach to design and predict the outcomes of experiments on tokamaks today. The capability to predict the plasma confinement and core profiles with a quantified uncertainty, based on a multi-machine, international, database of experience, will provide confidence that a proposed discharge will remain within the operational limits of the tokamak. Developing this predictive capability for the first generation of burning plasma devices, beginning with ITER, and progressing to tokamak demonstration reactors, is a critical mission of fusion energy research. Major advances have been made implementing this predict first methodology on today’s tokamaks. An overview of several of these recent advances will be presented, providing the integrated modeling foundations of the experimental successes. The first steps to include boundary plasmas, and tokamak control systems, have been made. A commitment to predicting experiments as part of the planning process is needed in order to collect predictive accuracy data and evolve the models and software into a robust whole discharge pulse design simulator.
Intuitionistic fuzzy set-based time series forecasting model via delegeration of hesitancy degree to the major grade de-i-fuzzification and arithmetic rules based on centroid defuzzification
Authors: Alam Nik Muhammad Farhan Hakim N B , Ramli Nazirah , Mohd Ainun Hafizah
Published: August 2021

De-i-fuzzification is a process of converting the intuitionistic fuzzy set into a fuzzy set. It becomes one of the core procedures in fuzzy time series forecasting model based on the intuitionistic fuzzy set. In this paper, we propose a fuzzy time series forecasting model based on intuitionistic fuzzy set via de-i-fuzzification. The de-i-fuzzification approach used is assigning the hesitancy degree to the major grade. The data are partitioned into a few intervals using the frequency density-based method. The data in the fuzzy set form is then transformed into an intuitionistic fuzzy set using the definition of intuitionistic fuzzy set. The arithmetic rules based on centroid defuzzification is used to obtain the forecasted output. The model is implemented on the data of student enrolment at the University of Alabama. The results are then compared to forecasting method using classical fuzzy set and similar de-i-fuzzification approach using max-min operation. The proposed method outperforms the other two methods, thus supports the fact that intuitionistic fuzzy set is a generalization of a classical fuzzy set and gives better performance in forecasting.
Challenges of home learning during movement control order among UiTM Pahang students
Authors: Mohamed Siti Rosiah , Samsudin Syafiza Saila , Ismail Nazihah , Alam Nik Muhammad Farhan Hakim N B , Adnan Noor Izyan Mohamad
Published: August 2021

Due to the COVID-19 pandemic, the enforcement of the Movement Control Order (MCO) by theMalaysian government since March 2020 significantly impacted many sectors such as the economy, society, and others. MCO enforcement has made Malaysians spend most of their time staying at home, and even some have lost their income source. Another sector that has been greatly affected is the educational sector. Today’s landscape of education has changed dramatically with the phenomenal rise of virtual classes from home. Learning and teaching processes are undertaken remotely and on digital platforms to curb the spreading of the virus. This situation has affected the lesson and learning process from home to many of the several students in Malaysia. Therefore, this study investigates the challenges of home learning during MCO among students in the Universiti Teknologi MARA (UiTM) Pahang Branch. A simple random sampling technique was used to distribute the online survey questionnaires, involving a sample of 213 students. Besides, a descriptive statistic was used to study the students’ demographic characteristics according to the challenges. In contrast, logistic regression analysis was used to determine the factors associated with home learning challenges during MCO. Based on the findings, most male and female students were not well prepared for home learning during MCO, with a percentage of 71.60% and 69.70%, respectively. As a result, 79.81% agreed that home learning is more stressful than the physical classes on the campus. In comparison, 79.63% of Social Science and 83.02% of Science and Technology students claimed that the workload given is way more significant during online classes. Furthermore, this study concludes that the most associated challenges of home learning faced by the students during MCO are the abundance of workload and loss of interest in the subject.
Trends in groundwater changes driven by precipitation and anthropogenic activities on the southeast side of the Hu Line
Authors: Liu Kai , Li Xueke , Long Xin
Published: August 2021

Groundwater resources consumption and management play a crucial role in food-energy- water nexus. However, the trends in groundwater storage variability and its attribution remain unclear because of the combined effects of climatic and anthropogenic terms. Here we use satellites and monitoring well observations to reveal the trends in groundwater storage change (GWSC), which exhibits geographical heterogeneity over the southeast side of the Hu Line in China during 1979–2012. The GWSC in northern China showed a slight decrease from 1979 to 1997, and the declining pattern extended to surrounding regions from 1998 to 2012. A considerable fraction of the GWSC trend can be attributed jointly to precipitation variations and human water usage. The anthropogenic factors that are primarily associated with socioeconomic development contribute to ∼31% of the variability in GWSC. Water management policies carried out in recent years reasonably explain the recovery of GWSC across regions with declining groundwater in 2013–2019. A positive trend in GWSC is further projected (2020–2029), though with uncertainties.