bluuebunny/crossref_metadata_2025 huggingface dataset:
The eigenmodes for spinor quantum field theory in global de Sitter space–time
Authors: A. Letsios Vasileios
Published: March 2021

The mode solutions of the Dirac equation on N-dimensional de Sitter space–time (dSN) with (N − 1)-sphere spatial sections are obtained by analytically continuing the spinor eigenfunctions of the Dirac operator on the N-sphere (SN). The analogs of flat space–time positive frequency modes are identified, and a vacuum is defined. The transformation properties of the mode solutions under the de Sitter group double cover [Spin(N,1)] are studied. We reproduce the expression for the massless spinor Wightman two-point function in closed form using the mode-sum method. By using this closed-form expression and taking advantage of the maximal symmetry of dSN, we find an analytic expression for the spinor parallel propagator. The latter is used to construct the massive Wightman two-point function in closed form.
On streamwise velocity spectra models with fractal and long-memory effects
Authors: Laudani Rossella , Zhang Dansong , Faouzi Tarik , Porcu Emilio , Ostoja-Starzewski Martin , Chamorro Leonardo P.
Published: March 2021

Using theoretical arguments, we present two novel spectrum models of the streamwise velocity component with robust correlation structures, which account for and decouple the fractal dimension and Hurst effect. The formulations that use isotropic concepts are adapted from the modern probability theory using the so-called generalized Cauchy and Dagum models, which belong to wide-sense-stationary random fields. A complementary inspection of these two models with field data from a met-tower-mounted sonic anemometer located within the atmospheric surface layer reveals good agreement and better performance than other conventionally used isotropic-based models of streamwise velocity spectra. The fractal dimension, D, of both models is consistent with the well-known Kolmogorov −5/3 power law in the inertial sub-range. For completeness, the study includes a derivation of the explicit forms of the energy spectral densities of the Cauchy and Dagum covariances.
Dispersion calibration for the National Ignition Facility electron–positron–proton spectrometers for intense laser matter interactions
Authors: von der Linden Jens , Ramos-Méndez José , Faddegon Bruce , Massin Devan , Fiksel Gennady , Holder Joe P. , Willingale Louise , Peebles Jonathan , Edwards Matthew R. , Chen Hui
Published: March 2021

Electron–positron pairs, produced in intense laser–solid interactions, are diagnosed using magnetic spectrometers with image plates, such as the National Ignition Facility Electron–Positron–Proton Spectrometers (EPPSs). Although modeling can help infer the quantitative value, the accuracy of the models needs to be verified to ensure measurement quality. The dispersion of low-energy electrons and positrons may be affected by fringe magnetic fields near the entrance of the EPPS. We have calibrated the EPPS with six electron beams from a Siemens Oncor linear accelerator (linac) ranging in energy from 2.7 MeV to 15.2 MeV as they enter the spectrometer. A Geant4 Tool for Particle Simulation Monte Carlo simulation was set up to match depth dose curves and lateral profiles measured in water at 100 cm source–surface distance. An accurate relationship was established between the bending magnet current setting and the energy of the electron beam at the exit window. The simulations and measurements were used to determine the energy distributions of the six electron beams at the EPPS slit. Analysis of the scanned image plates together with the determined energy distribution arriving in the spectrometer provides improved dispersion curves for the EPPS.
Collisionless particle dynamics in trap sections with helical corrugation
Authors: Chernoshtanov Ivan S. , Ayupov Dmitry A.
Published: March 2021

Collisionless particle dynamics in a helical magnetic mirror is investigated by methods of the Hamilton dynamics. In the limit of small Larmor radius, the Hamiltonian is fully integrable and particle trajectories can be divided into three types, differing in the direction of the drift velocity. The structure of the trajectories of resonant particles and the width of the resonance are studied. The influence of weak axi-symmetrical corrugation on the particle dynamics and efficiency of plasma flow suppression through a helical mirror are discussed.
Suppression of interface states between nitride-based gate dielectrics and ultrathin-barrier AlGaN/GaN heterostructure with in situ remote plasma pretreatments
Authors: Guo Fuqiang , Huang Sen , Wang Xinhua , Luan Tiantian , Shi Wen , Deng Kexin , Fan Jie , Yin Haibo , Shi Jingyuan , Mu Fengwen , Wei Ke , Liu Xinyu
Published: March 2021

A silicon nitride (SiNx) film deposited at 500 °C by plasma-enhanced atomic layer deposition (PEALD) is employed as the gate dielectric for GaN-based metal-insulator-semiconductor high electron mobility transistors (MIS-HEMTs). An interface enhancement technology featuring in situ low-damage NH3/N2 remote plasma pretreatments (RPPs) is developed prior to the SiNx gate dielectric deposition, which contributes to an improved surface morphology while remarkably suppressed interface oxides. It is revealed by constant-capacitance deep-level transient spectroscopy that both shallow and deep states at the PEALD-SiNx/III-nitride interface are reduced by about one order of magnitude by the RPP. The in situ RPP and PEALD-SiNx gate dielectric process are implemented into fabrication of enhancement-mode MIS-HEMTs on an ultrathin-barrier AlGaN/GaN heterostructure technology platform. The fabricated MIS-HEMTs deliver an improved threshold stability and maximum output current as compared with devices without the RPP.
Flexible and wearable piezoelectric nanogenerators based on P(VDF-TrFE)/SnS nanocomposite micropillar array
Authors: Zhai Wenchao , Zhu Laipan , Berbille Andy , Wang Zhong Lin
Published: March 2021

Polymer piezoelectric nanogenerators (PENGs) have attracted extensive interest in mechanical energy conversion and wearable electronics for the advantages they have to offer owing some of their characteristics, e.g., the fact that they are light weight, possess a desirable flexibility, and benefit from a high adaptability and simple large-scale manufacturing processes. In this paper, a high-performance organic flexible PENG based on a poly(vinylidene fluoride-trifluorethylene) [P(VDF-TrFE)] film doped with a SnS nanosheet (NS) micropillar array has been prepared and characterized. The piezoelectric coefficient of the P(VDF-TrFE)/SnS NSs (0.3 wt. %) nanocomposite has been greatly enhanced compared with that of the pristine P(VDF-TrFE) film, from 13 to 21 pC N−1. It also demonstrates outstanding open-circuit voltage (Voc) and short-circuit current (Isc) outputs of 17.28 V cm−2 and 0.94 μA cm−2 under the pressure of 0.5 MPa, which represents a 6-fold and 4-fold improvement, respectively, compared with what a neat P(VDF-TrFE) film was able to deliver. The device was capable of producing a high output power density of 10.69 μW cm−2 under an applied pressure of 0.5 MPa. The dramatic enhancement obtained using nanocomposite micropillar array films results from a more developed β-phase content in the organic film, the higher piezoelectric properties of SnS NSs, and the better alignment of dipoles induced by the micropillar array structure. These remarkably enhanced PENG performances seem to hold much promise for the development of wearable electronics exploiting ambient mechanical energy, thanks to its ability to produce different signals depending on the nature of the source of stimuli.
Charge collection in h-BN neutron detectors at elevated temperatures
Authors: Li J. , Maity A. , Grenadier S. J. , Lin J. Y. , Jiang H. X.
Published: March 2021

Many of the neutron detector applications are in the environments with harsh conditions such as high temperatures. We report here the measurements of charge collection parameters of hexagonal boron nitride (h-BN) detectors at elevated temperatures, including the electron mobility-lifetime product (μτ) and surface recombination field (s/μ). It was found that μτ is increased, while s/μ is decreased as temperature increases. The temperature dependence of the surface recombination field (s/μ) revealed that electrons trapped in the surface states tend to thermally activate to the bulk region at higher temperatures with an activation energy of about 0.22 eV, leading to a reduction in the density of the charged surface states at elevated temperatures. Consequently, the charge collection efficiency is enhanced at elevated temperatures due to a reduced surface recombination field and increased electron mobility-lifetime product. The results suggested that h-BN neutron detectors are favorable for high temperature operation.
Semi-analytic model of a carbon fiber thermal-field emitter
Authors: Jensen Kevin L. , Connelly Joseph M. , Petillo John J. , Harris John R. , Ovtchinnikov Serguei , Jensen Aaron J. , Burke John , Cahay Marc , Ludwick J. , Tripathi G. , Sanchez-Roddy Jacob , Puentes Daniel
Published: March 2021

Carbon fibers passing current are subject to resistive heating. When failure occurs, this is related to their local temperature. The failure temperature and its location are estimated. The temperature variation is calculated using analytical models for electrical and thermal conductivities based on the temperature dependent electron–phonon relaxation time. In the absence of radiative heat loss, an analytic expression of temperature along the fiber is given from which a maximum possible emission current is derived and is governed by a single introduced parameter ωo. A method of treating the radiative heat loss is developed and is governed by a second parameter γ, which allows a rapid numerical means to calculate the correction to the analytic form. Heat variation along a thick carbon fiber is contrasted to that along a multi-walled carbon nanotube (MWNT): it is shown that the relative magnitude of ωo compared to γ determines that the analytical formula is a good approximation for MWNTs but requires numerical correction for fibers. Furthermore, it is shown that the analytical form of ωo specified a maximum current beyond which the carbon emitter fails due to thermal runaway. The theoretical models are used to interpret observed behavior of field emission from carbon fibers and the resulting damage they endure when the extracted field-emission current is high. Results from implementing the developed temperature variation model into the MICHELLE beam optics simulation code are presented, with an example application predicting the conditions for stable equilibrium operation as well as for the onset of fiber failure.
Kaposi’s sarcoma herpesvirus is associated with osteosarcoma in Xinjiang populations
Authors: Chen Qian , Chen Jiangtao , Li Yuqing , Liu Dawei , Zeng Yan , Tian Zheng , Yunus Akbar , Yang Yong , Lu Jie , Song Xinghua , Yuan Yan
Published: March 2021

Significance

A viral etiology of osteosarcoma was proposed previously but has never been proven by identifying any virus authentically associated with human osteosarcoma. The current study revealed an association of human osteosarcoma with KSHV infection in osteosarcoma patients of Xinjiang subgroups. First, this study provides evidence that supports a viral etiology of some human osteosarcomas. The gene expression profiling study showed that KSHV-positive osteosarcoma represents a distinct subtype of osteosarcoma which is of diagnostic, prognostic, and therapeutic significance. Second, KSHV-associated osteosarcomas occur preferentially in children and young adults, predicting that KSHV-positive children in KSHV-endemic regions may be at significant risk for osteosarcoma. Third, these findings extend the range of human cancers associated with viruses.
Superoxide is promoted by sucrose and affects amplitude of circadian rhythms in the evening
Authors: Román Ángela , Li Xiang , Deng Dongjing , Davey John W. , James Sally , Graham Ian A. , Haydon Michael J.
Published: March 2021

Significance

Distinguishing the effects of light and sugars in photoautotrophic cells is challenging. The circadian system is a regulatory network that integrates light and metabolic signals and controls rhythmic physiology and growth. Our experimental approach has defined a light-independent, sugar-regulated transcriptome in
Arabidopsis
and revealed reactive oxygen species (ROS) as a prominent feature. ROS are byproducts of photosynthetic metabolism and oscillate with circadian rhythms but have not previously been demonstrated as inputs to the plant circadian oscillator. Our data suggest a role for superoxide as a rhythmic sugar signal which acts in the evening and affects circadian gene expression and growth.
Charting the sequence-activity landscape of peptide inhibitors of translation termination
Authors: Baliga Chetana , Brown Tyler J. , Florin Tanja , Colon Sarah , Shah Vallari , Skowron Kornelia J. , Kefi Amira , Szal Teresa , Klepacki Dorota , Moore Terry W. , Vázquez-Laslop Nora , Mankin Alexander S.
Published: March 2021

Significance

Apidaecin (Api) is a ribosome-targeting proline-rich antimicrobial peptide with a unique mechanism of action. Api’s activity against Gram-negative pathogens makes it an attractive candidate for developing new antibiotics. The approaches based on analyzing the antibacterial activity of chemically synthesized peptides fail to distinguish the effects upon cellular uptake from those affecting the on-target activity. By expressing a comprehensive library of
api
gene mutants in the bacterial cell and analyzing the library composition by next-generation sequencing, we identified in a single experiment the on-target activity of every single-amino-acid mutant. Location of the inactivating mutations defined the peptide’s pharmacophore, which is confined to five C-terminal residues. Identification of mutations preserving activity delineated the sequence space available for modifying the peptide’s antibiotic properties.
Second Virtual Pitch Shift in Cochlea Observed In Situ via Laser Interferometry
Authors: Long Zhang-Cai , Zhang Yan-Ping , Luo Lin
Published: March 2021

Pitch is the most important auditory perception characteristic of sound with respect to speech intelligibility and music appreciation, and corresponds to a frequency of sound stimulus. However, in some cases, we can perceive virtual pitch, where the corresponding frequency component does not exist in the stimulating sound. This virtual pitch contains a deviation from the de Boer pitch shift formula, which is known as second pitch shift. It has been theoretically suggested that nonlinear dynamics in the cochlea or in the neural network produce a nonlinear resonance with a frequency corresponding to the virtual pitch; however, there is no direct experimental observation to support this theory. The second virtual pitch shift, expressed via basilar membrane nonlinear vibration temporal patterns, and consistent with psychoacoustic experiments, is observed in situ in the cochlea via laser interferometry.
Tuning Thermal Conductivity in Si Nanowires with Patterned Structures
Authors: Zhu Gui-ping , Zhao Chang-wei , Wang Xi-wen , Wang Jian
Published: March 2021

Tuning the thermal conductivity of silicon nanowires (Si-NWs) is essential for realization of future thermoelectric devices. The corresponding management of thermal transport is strongly related to the scattering of phonons, which are the primary heat carriers in Si-NWs. Using the molecular dynamics method, we find that the scattering of phonons from internal body defects is stronger than that from surface structures in the low-porosity range. Based on our simulations, we propose the concept of an exponential decay in thermal conductivity with porosity, specifically in the low-porosity range. In contrast, the thermal conductivity of Si-NWs with a higher porosity approaches the amorphous limit, and is insensitive to specific phonon scattering processes. Our findings contribute to a better understanding of the tuning of thermal conductivity in Si-NWs by means of patterned nanostructures, and may provide valuable insights into the optimal design of one-dimensional thermoelectric materials.
Scaling Behavior between Heat Capacity and Thermal Expansion in Solids
Authors: Tang Meibo , Pan Xiuhong , Zhang Minghui , Wen Haiqin
Published: March 2021

We experimentally analyze the heat capacity and thermal expansion of reference solids in a wide temperature range from several Kelvin to melting temperature, and establish a universal double-linear relation between the experimental heat capacity C
p and thermal expansion β, which is different from the previous models. The universal behavior between heat capacity and thermal expansion is important to predict the thermodynamic parameters at constant pressure, and is helpful for understanding the nature of thermal properties in solids.
Rational Design of Two-Dimensional Magnetic Chromium Borides Based on First-Principles Calculation
Authors: Zhang Yi-Lin , Zhang Yue-Yu , Ni Jin-Yang , Yang Ji-Hui , Xiang Hong-Jun , Gong Xin-Gao
Published: March 2021

Two-dimensional (2D) magnetic materials have been experimentally recognized recently, however, the Curie temperatures (T
C) of known 2D systems are quite low. Generally, magnetic systems can be seen as constituent magnetic elements providing spins and the non-magnetic elements providing frameworks to host the magnetic elements. Short bond lengths between the magnetic and non-magnetic elements would be beneficial for strong magnetic interactions and thus high T
C. Based on this, we propose to combine the magnetic element Cr and the non-magnetic element boron to design novel 2D magnetic systems. Using our self-developed software package IM2ODE, we design a series of chromium-boride based 2D magnetic materials. Nine stable magnetic systems are identified. Among them, we find that CrB4-I, CrB4-II and CrB5-I with common structural units [CrB8] are ferromagnetic metals with estimated T
C of 270 K, 120 K and 110 K, respectively. On the other hand, five CrB3 phases with structural units [Cr2B12] are antiferromagnetic metals. Additionally, we also find one antiferromagnetic semiconductor CrB2-I. Our work may open new directions for identifying 2D magnetic systems with high T
C.
Towards Fabrication of Atomic Dopant Wires via Monolayer Doping Patterned by Resist-Free Lithography
Authors: Zhang Chufan , Li Ke , Zang Xiaoxian , Ma Fuyuan , Dan Yaping
Published: March 2021

Fabrication of atomic dopant wires at large scale is challenging. We explored the feasibility to fabricate atomic dopant wires by nano-patterning self-assembled dopant carrying molecular monolayers via a resist-free lithographic approach. The resist-free lithography is to use electron beam exposure to decompose hydrocarbon contaminants in vacuum chamber into amorphous carbon that serves as an etching mask for nanopatterning the phosphorus-bearing monolayers. Dopant wires were fabricated in silicon by patterning diethyl vinylphosphonate monolayers into lines with a width ranging from 1 μm down to 8 nm. The dopants were subsequently driven into silicon to form dopant wires by rapid thermal annealing. Electrical measurements show a linear correlation between wire width and conductance, indicating the success of the monolayer patterning process at nanoscale. The dopant wires can be potentially scaled down to atomic scale if the dopant thermal diffusion can be mitigated.
The effect of fermentation time and addition of crude cellulase to concentration of bioethanol in bagasse fermentation
Authors: Rulianah S , Prayitno P , Indiastari A , Fatmawati D
Published: March 2021

Bagasse is a solid waste from the sugar cane milling process in the sugar industry. Bagasse contains lignin, cellulose and hemicellulose, which through the fermentation process by Phanerochaete chrysosporium can produce crude cellulase, furthermore cellulase and other enzymes can be used in bagasse fermentation to produce bioethanol. The purpose of this study was to determine the effect of fermentation time and the addition of crude cellulase to the yield and concentration of bioethanol produced in bagasse fermentation. The research was carried out with the stages of the process: Preparation of raw materials (bagasse), Preparation of crude cellulase, Fermentation process, Product analysis (Bioethanol). The variables used in the experiment were fermentation time (96, 120, and 144 hours) and the addition of crude cellulase (10%, 20%, 30%, 40%, and 50% (v/v)). Analysis of crude cellulase activity using the DNS method, while the analysis of bioethanol concentration using the chromatography methods. The results showed that the maximum yield was 16.24% and the highest bioethanol concentration of 11.04% was obtained at the time of fermentation of 144 hours and the addition of crude cellulase by 50% (v/v).
Smart ecosystem for hydroponic land in the hydroponic farmers group guided by CSR PT. Otsuka Indonesia as an improved quality and quantity of harvest results
Authors: Aji D K P , Nurhasan U , Arianto R , Triswidrananta O D
Published: March 2021

Corporate Social Responsibility (CSR) is a community development program managed by PT. Otsuka Indonesia, one of which is form a hydroponic farmer community. In the activity of fostering hydroponic farmers there are several problems, namely the process of plant nursery, seeding, and harvesting are still carried out conventionally, while the assisted farmers do not have much time to supervise because they have a core job. Based on these problems, this study will focus on solving the problem of hydroponic plant supervision that can be known directly by farmers and also from the CSR of PT. Otsuka Indonesia. In completing the research, the steps carried out were based on the CRISP-DM (Cross Industry Standard Process for Data Mining) methodology. The factors used in solving the problem are the type of hydroponic plants, the acidity of the soil, the intensity of sunlight, the ambient temperature of the hydroponic plants, the water level and periodic reporting as needed in the form of a Smart Ecosystem. For this reason, it is necessary to build a device from an Arduino microcontroller based on IoT so that supervision of the hydroponic planting process can be done without having to be in hydroponic land and get reports every period of the development of hydroponic plants in the application. By using this device, it is hoped that many hydroponic farmers will use it so that during the hydroponic vegetable production process it can be in accordance with the old standards of the nursery until it is worth selling.
Deep Recurrent Q Reinforcement Learning model to Predict the Alzheimer Disease using Smart Home Sensor Data
Authors: Dhanusha C. , Senthil Kumar A.V.
Published: March 2021

Early detection of alzheimer disease is an essential process of the elderly persons when they are with the mild cognitive impairments. This work adapts the smart home based alzheimer disease detection by recording the daily activities of the resident’s equipped with the sensor devices in their appliances as smart home. Using sensor data based clinical assessment of alzheimer patient is very complex as it is uncertain to predict such vague monitoring and understanding its deep characteristics. To acquire the deep characteristics of sensor dataset unlike the existing conventional supervised learning paradigm, this paper constructs an optimized self-learning model known as reinforcement learning process. This proposed model Deep Recurrent Q Learning based Reinforcement Model (DRQLRM) Process comprised of two stages they are pretraining using recurrent neural network to overcome the overfitting and fine tuning of the parameters involved in deep neural network and Deep Q learning process is used as reinforcement approach which uses the agents rewards and penalties to determine the optimal agents and their experience to predict the unknown pattern in the uncertain condition in effective way. The proposed model produced better result in CASA smart home test bed for investigating the presence of alzheimer
Gasoline Engine Simulation Software: A Comparison Review
Authors: Ghanim Wisam S , Ahmed Omer K , Ali Obed M
Published: March 2021

In this review, a survey of previous studies has been conducted on the use of simulation software to evaluate the performance of spark igniting engines. Some of the gaps in the simulation software used by researchers requiring further research and consideration of their potential impact on the writing of the topic under discussion. The results of the simulation software have led to the ability of these models to predict engine performance, and show good agreement between the experimental results and the results predicted by the simulation software. These findings increase the reliability of simulation software, which can replace the experimental tests and in turn reduce the cost. This will also provide a platform for the researchers to expand their experimental through varying the different parameters instantaneously to get the optimum performance criteria
Single-cell genomics to study developmental cell fate decisions in zebrafish
Authors: Moreno-Ayala Roberto , Junker Jan Philipp
Published: March 2021

New developments in single-cell genomics have transformed developmental biology in recent years by enabling systematic analysis of embryonic cell types and differentiation trajectories. Ongoing efforts in experimental and computational method development aim to reveal gene-regulatory mechanisms and to provide additional spatio-temporal information about developmental cell fate decisions. Here, we discuss recent technological developments as well as biological applications of single-cell genomics, with a particular focus on analysis of developmental cell fate decisions. Although the approaches described here are generally applicable to a broad range of model systems, we focus our discussion on applications in zebrafish, which has proven to be a particularly powerful model organism for establishing novel methods in single-cell genomics.
MixTwice: large-scale hypothesis testing for peptide arrays by variance mixing
Authors: Zheng Zihao , Mergaert Aisha M. , Ong Irene M. , Shelef Miriam A. , Newton Michael A.
Published: March 2021

Peptide microarrays have emerged as a powerful technology in immunoproteomics as they provide a tool to measure the abundance of different antibodies in patient serum samples. The high dimensionality and small sample size of many experiments challenge conventional statistical approaches, including those aiming to control the false discovery rate (FDR). Motivated by limitations in reproducibility and power of current methods, we advance an empirical Bayesian tool that computes local FDR statistics and local false sign rate statistics when provided with data on estimated effects and estimated standard errors from all the measured peptides. As the name suggests, the MixTwice tool involves the estimation of two mixing distributions, one on underlying effects and one on underlying variance parameters. Constrained optimization techniques provide for model fitting of mixing distributions under weak shape constraints (unimodality of the effect distribution). Numerical experiments show that MixTwice can accurately estimate generative parameters and powerfully identify non-null peptides. In a peptide array study of rheumatoid arthritis, MixTwice recovers meaningful peptide markers in one case where the signal is weak, and has strong reproducibility properties in one case where the signal is strong.

Availabilityand implementation

MixTwice is available as an R software package https://cran.r-project.org/web/packages/MixTwice/.

Supplementary information

Supplementary data are available at Bioinformatics online.
Challenges in Implementing Restorative Justice with Older Adults: Institutional Gatekeepers and Social Barriers
Authors: Avieli Hila , Band Winterstein Tova , Gal Tali
Published: March 2021

Despite the consensus regarding the importance of restorative justice (RJ) as an alternative to the criminal justice system, some professionals and researchers have pointed out the challenges involved in its implementation with older adults who have been victimised. The aim of the present study was to explore the primary obstructions to implementing RJ intervention with older adults who have been victimised, as perceived by RJ facilitators, using the conceptual framework of social constructivism. An interpretive phenomenological analysis perspective was used to analyse the narratives of seven RJ facilitators, all of them highly experienced social workers. The narratives revealed three themes: the interpersonal and familial arena—the older person and his/her family as gatekeepers; the institutional arena—judicial and medical system personnel as gatekeepers; and the professional arena—RJ facilitators as gatekeepers. The findings suggest that some individuals and institutions maintain the conservative agenda of gatekeeping older adults to prevent them from encountering any danger. These findings indicate that, in keeping with the social work code of ethics, social workers need to consider older adults’ right to self-determination in RJ contexts.
Seismicity around the trench axis and outer-rise region of the southern Japan Trench, south of the main rupture area of the 2011 Tohoku-oki earthquake
Authors: Obana Koichiro , Fujie Gou , Yamamoto Yojiro , Kaiho Yuka , Nakamura Yasuyuki , Miura Seiichi , Kodaira Shuichi
Published: March 2021

The 2011 Mw 9.0 Tohoku-oki earthquake ruptured the subduction megathrust fault in the central Japan Trench. We investigated the aftershock activity in the southern Japan Trench to the south of the main rupture area using ocean bottom seismographs deployed both landward and seaward of the trench. In the trench-outer rise region seaward of the trench axis, we identified several ∼100-km-long linear earthquake trends both parallel and oblique to the southern Japan Trench. The earthquake trend oblique to the southern Japan Trench is a southward extension of the trench-parallel linear earthquake trend in the central to northern Japan Trench. The trench-parallel normal-faults in the trench-outer rise region could extend linearly, despite the change of the trench strike from N–S to NNE–SSW to the south of the main rupture area. Normal-faults oblique to the trench should be considered as substantial parts of large intraplate normal-faulting earthquakes. In addition, intraplate seismicity coinciding with the lower velocity oceanic mantle suggest that the structure heterogeneity would be indicative of normal-faults extending into the mantle. In the trench landward area, earthquake activity showed along-trench variations. Earthquakes along the shallow megathrust interface near the trench were observed south of 37°N. These shallow near-trench regular earthquakes, which are located close to the episodic tremors and temporally correlated with the tremor activities, suggest that the afterslip on the plate interface likely extended to the shallow plate interface close to the trench axis. Smaller spatial scale structure heterogeneity, such as the thickness variation in the channel-like low-velocity sedimentary unit, likely relate to the proximity of the regular earthquakes and slow slip which results in the formation of diverse slip behaviours in the shallow subduction zone of the southern Japan Trench.
Sleep Problems, Cumulative Risks, and Psychological Functioning in Early Childhood
Authors: Williamson Ariel A , Davenport Mattina , Cicalese Olivia , Mindell Jodi A
Published: March 2021

Background

Sleep problems and cumulative risk factors (e.g., caregiver depression, socioeconomic disadvantage) have independently been linked to adverse child development, but few studies have examined the interplay of these factors. We examined whether cumulative risk exposure moderated the link between sleep problems, including insomnia and poor sleep health, and child psychological outcomes.

Methods

205 caregiver-child dyads (child Mage = 3.3 years; 53.7% girls; 62.9% Black, 22.4% non-Latinx White, and 4.4% Latinx; 85.4% maternal caregiver reporter) completed child sleep, family sociodemographic, and child psychological functioning (internalizing, externalizing, and executive functioning) questionnaires. Indexes of cumulative risk exposure, insomnia symptoms, and poor sleep health were created.

Results

Ninety percent of children had ≥1 cumulative risks, 62.9% had ≥1 insomnia symptom, and 84.5% had ≥1 poor sleep health behavior. Increased insomnia symptoms were significantly associated with increased child internalizing, externalizing, and global executive functioning impairments controlling for child age, race/ethnicity, and sex. Poor sleep health behaviors were associated with internalizing concerns. Cumulative risk exposure was not associated with outcomes but moderated the association between insomnia symptoms and all psychological outcomes, such that children with higher cumulative risk exposure and insomnia symptoms had the greatest impairments. Children with the poorest sleep health behaviors and highest cumulative risks had the greatest internalizing concerns.

Conclusions

Insomnia symptoms in particular are associated with poor child outcomes, which are exacerbated when accompanied by greater cumulative risk exposure. Clinicians should assess sleep when treating early psychological concerns, especially within the context of increased cumulative risks.
Repriming DNA synthesis: an intrinsic restart pathway that maintains efficient genome replication
Authors: Bainbridge Lewis J , Teague Rebecca , Doherty Aidan J
Published: March 2021

To bypass a diverse range of fork stalling impediments encountered during genome replication, cells possess a variety of DNA damage tolerance (DDT) mechanisms including translesion synthesis, template switching, and fork reversal. These pathways function to bypass obstacles and allow efficient DNA synthesis to be maintained. In addition, lagging strand obstacles can also be circumvented by downstream priming during Okazaki fragment generation, leaving gaps to be filled post-replication. Whether repriming occurs on the leading strand has been intensely debated over the past half-century. Early studies indicated that both DNA strands were synthesised discontinuously. Although later studies suggested that leading strand synthesis was continuous, leading to the preferred semi-discontinuous replication model. However, more recently it has been established that replicative primases can perform leading strand repriming in prokaryotes. An analogous fork restart mechanism has also been identified in most eukaryotes, which possess a specialist primase called PrimPol that conducts repriming downstream of stalling lesions and structures. PrimPol also plays a more general role in maintaining efficient fork progression. Here, we review and discuss the historical evidence and recent discoveries that substantiate repriming as an intrinsic replication restart pathway for maintaining efficient genome duplication across all domains of life.
Bound2Learn: a machine learning approach for classification of DNA-bound proteins from single-molecule tracking experiments
Authors: Kapadia Nitin , El-Hajj Ziad W , Reyes-Lamothe Rodrigo
Published: March 2021

DNA-bound proteins are essential elements for the maintenance, regulation, and use of the genome. The time they spend bound to DNA provides useful information on their stability within protein complexes and insight into the understanding of biological processes. Single-particle tracking allows for direct visualization of protein–DNA kinetics, however, identifying whether a molecule is bound to DNA can be non-trivial. Further complications arise when tracking molecules for extended durations in processes with slow kinetics. We developed a machine learning approach, termed Bound2Learn, using output from a widely used tracking software, to robustly classify tracks in order to accurately estimate residence times. We validated our approach in silico, and in live-cell data from Escherichia coli and Saccharomyces cerevisiae. Our method has the potential for broad utility and is applicable to other organisms.
Burnout Rate and Risk Factors among Anesthesiologists in the United States
Authors: Afonso Anoushka M. , Cadwell Joshua B. , Staffa Steven J. , Zurakowski David , Vinson Amy E.
Published: March 2021

Background

Physician burnout, widespread across medicine, is linked to poorer physician quality of life and reduced quality of care. Data on prevalence of and risk factors for burnout among anesthesiologists are limited. The objective of the current study was to improve understanding of burnout in anesthesiologists, identify workplace and personal factors associated with burnout among anesthesiologists, and quantify their strength of association.

Methods

During March 2020, the authors surveyed member anesthesiologists of the American Society of Anesthesiologists. Burnout was assessed using the Maslach Burnout Inventory Human Services Survey. Additional survey questions queried workplace and personal factors. The primary research question was to assess rates of high risk for burnout (scores of at least 27 on the emotional exhaustion subscale and/or at least 10 on the depersonalization subscale of the Maslach Burnout Inventory Human Services Survey) and burnout syndrome (demonstrating all three burnout dimensions, consistent with the World Health Organization definition). The secondary research question was to identify associated risk factors.

Results

Of 28,677 anesthesiologists contacted, 13.6% (3,898) completed the survey; 59.2% (2,307 of 3,898) were at high risk of burnout, and 13.8% (539 of 3,898) met criteria for burnout syndrome. On multivariable analysis, perceived lack of support at work (odds ratio, 6.7; 95% CI, 5.3 to 8.5); working greater than or equal to 40 h/week (odds ratio, 2.22; 95% CI, 1.80 to 2.75); lesbian, gay, bisexual, transgender/transsexual, queer/questioning, intersex, and asexual status (odds ratio, 2.21; 95% CI, 1.35 to 3.63); and perceived staffing shortages (odds ratio, 2.06; 95% CI, 1.76 to 2.42) were independently associated with high risk for burnout. Perceived lack of support at work (odds ratio, 10.0; 95% CI, 5.4 to 18.3) and home (odds ratio, 2.13; 95% CI, 1.69 to 2.69) were most strongly associated with burnout syndrome.

Conclusions

The prevalence of burnout among anesthesiologists is high, with workplace factors weighing heavily. The authors identified risk factors for burnout, especially perceived support in the workplace, where focused interventions may be effective in reducing burnout.

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Evaluation of a Home Visiting Program
Authors: Lowe Kelsi , Cartagena Diana , Gudger Kaitlin
Published: March 2021

Home visiting programs provide families with an array of services that contribute to decreased infant and maternal morbidity and mortality. However, little is known as to how mothers perceive participation in home visiting programs, and questions remain regarding what improvements can be made to better serve these families. The purpose of this program evaluation was to assess mothers' perceived benefits and barriers to participation in established home visiting and outreach programs at Child Developmental Resources (CDR) in Williamsburg, Virginia. The program evaluation was a descriptive project consisting of 30-minute telephone interviews. Participants included 23 English-speaking mothers enrolled in CDR programs. Maternal demographics and perception of benefits/barriers were measured. Descriptive statistics were performed to describe sample demographics and outcome variables. Overall, most mothers perceived CDR programs as beneficial and were very satisfied with the services; however, a few changes could be made to improve programs and combat barriers to participation. Potential alternatives to supplement programs were suggested including the use of mobile technology in the participant's home.
Designing research studies in writer’s cramp dystonia: an analysis of automated writing measures
Authors: Bukhari-Parlakturk Noreen , Lutz Michael , McConnell Alec , Al-Khalidi Hussein , Wang Joyce En-Hua , Scott Burton , Termsarasab Pichet , Appelbaum Lawrence , Calakos Nicole
Published: March 2021

Background

Writer’s cramp (WC) dystonia presents with abnormal postures during the task of writing and is an ideal dystonia subtype to study disease mechanisms for all forms of focal dystonia. Development of novel therapies is contingent on identifying sensitive and specific measures that can relate to the clinical syndrome and achieve a realistic sample size to power clinical research study for a rare disease. Although there have been prior studies employing automated measures of writing kinematics, it remains unclear which measures can distinguish WC subjects with high sensitivity and specificity and how these measures relate to clinician rating scales and patient-reported disability. The goal of this study was to: 1-identify automated writing measures that distinguish WC from healthy subjects, 2-measure sensitivity and specificity of these automated measures as well as their association with established dystonia rating scales, and 3-determine the sample size needed for each automated measure to power a clinical research study.

Methods

21 WC dystonia and 22 healthy subjects performed a sentence-copying assessment on a digital tablet in a kinematic software and hand recognition software. The sensitivity and specificity of automated measures was calculated using a logistic regression model. Measures were then correlated with examiner and patient rating scales. Power analysis was performed for 2 clinical research designs using these automated measures.

Results

Of the 23 automated writing measures analyzed, only 3 measures showed promise for use in a clinical research study. The automated measures of writing legibility, duration, and peak acceleration were able to distinguish WC from healthy controls with high sensitivity and specificity, correlated with examiner-rated dystonia sub-score measures and demonstrated relatively smaller sample sizes suitable for research studies in a rare disease population.

Discussion

We identified novel automated writing outcome measures for use in clinical research studies of WC subjects which capture key aspects of the clinical disease and can serve as important readout of dystonia disease mechanism as well as future disease interventions.
COVID Symptoms, Symptom Clusters, and Predictors for Becoming a Long-Hauler: Looking for Clarity in the Haze of the Pandemic
Authors: Huang Yong , Pinto Melissa D. , Borelli Jessica L. , Mehrabadi Milad Asgari , Abrihim Heather , Dutt Nikil , Lambert Natalie , Nurmi Erika L. , Chakraborty Rana , Rahmani Amir M. , Downs Charles A.
Published: March 2021

Emerging data suggest that the effects of infection with SARS-CoV-2 are far reaching extending beyond those with severe acute disease. Specifically, the presence of persistent symptoms after apparent resolution from COVID-19 have frequently been reported throughout the pandemic by individuals labeled as “long-haulers”. The purpose of this study was to assess for symptoms at days 0-10 and 61+ among subjects with PCR-confirmed SARS-CoV-2 infection. The University of California COvid Research Data Set (UC CORDS) was used to identify 1407 records that met inclusion criteria. Symptoms attributable to COVID-19 were extracted from the electronic health record. Symptoms reported over the previous year prior to COVID-19 were excluded, using nonnegative matrix factorization (NMF) followed by graph lasso to assess relationships between symptoms. A model was developed predictive for becoming a long-hauler based on symptoms. 27% reported persistent symptoms after 60 days. Women were more likely to become long-haulers, and all age groups were represented with those aged 50 ± 20 years comprising 72% of cases. Presenting symptoms included palpitations, chronic rhinitis, dysgeusia, chills, insomnia, hyperhidrosis, anxiety, sore throat, and headache among others. We identified 5 symptom clusters at day 61+: chest pain-cough, dyspnea-cough, anxiety-tachycardia, abdominal pain-nausea, and low back pain-joint pain. Long-haulers represent a very significant public health concern, and there are no guidelines to address their diagnosis and management. Additional studies are urgently needed that focus on the physical, mental, and emotional impact of long-term COVID-19 survivors who become long-haulers.
Systematic review of the effects of pandemic confinements on body weight and their determinants
Authors: Khan Moien AB , Menon Preetha , Govender Romona , Samra Amal , Nauman Javaid , Ostlundh Linda , Mustafa Halla , Allaham Kholoud K , Smith Jane E.M. , Al Kaabi Juma M
Published: March 2021

Pandemics and subsequent lifestyle restrictions such as ‘lockdowns’ may have unintended consequences, including alterations in body weight. Understanding the impact and the mechanisms affecting body weight is paramount for planning effective public health measures for both now and future “lockdown”-type situations. This systematic review assesses and the impact of pandemic confinement on body weight and to identifies contributory factors. A comprehensive literature search was performed in seven electronic databases and in gray sources from their inception until 1stJuly 2020 with an update in PubMed and Scopus on 1stFebruary 2021. In total, 2,361 unique records were retrieved, of which 41 studies were identified eligible: 1 case control study, 14 cohort and 26 cross-sectional studies (469, 362 total participants). The participants ranged in age from 6–86 years. The proportion of female participants ranged from 37% to 100%. Pandemic confinements were associated with weight gain in 7.2%–72.4% of participants and weight loss in 11.1%–32.0% of participants. Weight gain ranged from 0.6 (±1.3) to 3.0 (±2.4) kg, and weight loss ranged from 2.0 (±1.4) to 2.9 (±1.5) kg. Weight gain occurred predominantly in participants who were already overweight or obese. Associated factors included increased consumption of unhealthy food with decreased intake of healthy fresh fruits and vegetables, changes in physical activity, and altered sleep patterns. Weight loss during the pandemic was observed in individuals with previous low weight, and those who ate less and were more physically active before lock down. Associated factors included increased intake of fruits and vegetables, drinking more water and consuming no alcohol. Maintaining a stable weight was more difficult in populations with reduced income, particularly in individuals with lower educational attainment. The findings of this systematic review highlight the short-term effects of pandemic confinements. Learning from the “lockdown” experience is fundamental if we are to prepare for the next wave; a holistic, reactive, tailored response is needed involving multiple providers.