bluuebunny/crossref_metadata_2025_split huggingface dataset:
Objective structured assessment of technical skill in temporal bone dissection: validation of a novel tool
Authors: Stavrakas M , Menexes G , Triaridis S , Bamidis P , Constantinidis J , Karkos P D 
Published: May 2021

AbstractObjectiveThis study developed an assessment tool that was based on the objective structured assessment for technical skills principles, to be used for evaluation of surgical skills in cortical mastoidectomy. The objective structured assessment of technical skill is a well-established tool for evaluation of surgical ability. This study also aimed to identify the best material and printing method to make a three-dimensional printed temporal bone model.MethodsTwenty-four otolaryngologists in training were asked to perform a cortical mastoidectomy on a three-dimensional printed temporal bone (selective laser sintering resin). They were scored according to the objective structured assessment of technical skill in temporal bone dissection tool developed in this study and an already validated global rating scale.ResultsTwo external assessors scored the candidates, and it was concluded that the objective structured assessment of technical skill in temporal bone dissection tool demonstrated some main aspects of validity and reliability that can be used in training and performance evaluation of technical skills in mastoid surgery.ConclusionApart from validating the new tool for temporal bone dissection training, the study showed that evolving three-dimensional printing technologies is of high value in simulation training with several advantages over traditional teaching methods.
Filling the Data Gaps Within GRACE Missions Using Singular Spectrum Analysis
Authors: Yi Shuang , Sneeuw Nico 
Published: May 2021

AbstractDozens of missing epochs in the monthly gravity product of the satellite mission Gravity Recovery and Climate Experiment (GRACE) and its follow‐on (GRACE‐FO) mission greatly inhibit the complete analysis and full utilization of the data. Despite previous attempts to handle this problem, a general all‐purpose gap‐filling solution is still lacking. Here we propose a non‐parametric, data‐adaptive and easy‐to‐implement approach—composed of the Singular Spectrum Analysis gap‐filling technique, cross‐validation, and spectral testing for significant components—to produce reasonable gap‐filling results in the form of spherical harmonic coefficients (SHCs). We demonstrate that this approach is adept at inferring missing data from long‐term and oscillatory changes extracted from available observations. A comparison in the spectral domain reveals that the gap‐filling result in the same signal intensity as the product of GRACE missions for spherical harmonic degrees below 30. As the degree increases above 30, the degree variance of the gap‐filling result decreases more rapidly than that of GRACE/GRACE‐FO SHCs, demonstrating effective suppression of noise. As a result, our approach can reduce noise in the oceans without sacrificing resolutions on land. The quality of the gap‐filling product is evaluated through comparison with a surface mass balance based estimate in Greenland, Swarm gravity solutions and a climate‐driven water storage model, all of which confirm the good performance of our results. This study makes a ready‐to‐use gap‐filling product in the form of SHCs together with proper error estimates available. Nonetheless, our method is also applicable to smoothed gridded observations.
Soil Microbes Transform Inorganic Carbon Into Organic Carbon by Dark Fixation Pathways in Desert Soil
Authors: Liu Zhen , Sun Yanfei , Zhang Yuqing , Feng Wei , Lai Zongrui , Qin Shugao 
Published: May 2021

AbstractSoil inorganic carbon (SIC) represents the main soil carbon pool in drylands with a high geologic residence time for carbon sequestration. Recent studies have shown that SIC is not stable as previously supposed, and can be employed by certain microbes and transformed into organics in soils; however, this transformation remains largely unexplored. We performed in situ 13C tracing in desert bulk soil and employed metagenomics to predict the microbial metabolic processes associated with carbon transformation. The tracing data showed that the 13C signature profile in soil organic carbon (SOC) originated from SIC with a carbon transformation content of 6.881 mg m−2 during the feeding periods, corresponding to a rate of 3.276 μg kg−1 d−1. Metagenomic analysis identified genes encoding enzymes related to microbial CO2 and fixation, accounting for 0.448% (based on Kyoto Encyclopedia of Genes and Genomes database) and 0.668% (based on Evolutionary genealogy of genes: Non‐supervised Orthologous Groups database) of all ascertained genes. Soil microbes, from a broad taxonomic range, harboring these genes mainly contributed toward chemoautotrophic and heterotrophic carbon fixation. Our results demonstrated that the microbes employed the chemoautotrophic and heterotrophic pathways, namely, dark microbial pathways, for SIC transformation into SOC. Although the amount of SOC derived from the dark microbial fixation process was not assessed, the present study highlights a neglected carbon transformation process mediated by soil microbes in drylands and provides insights into carbon transformation of SIC to SOC in dryland soil.
The Role of Spatial Gradient on Vertical Total Electron Content Extraction From Geodetic Very Long Baseline Interferometry Observation: Case Study CONT08 to CONT17‐L1
Authors: Etemadfard Hossein , Heinkelmann Robert , Hossainali Masoud Mashhadi , Schuh Harald 
Published: May 2021

AbstractGeodetic very long baseline interferometry (VLBI) observations are carried out, with the legacy system, using two well‐separated frequency bands in order to determine first‐order ionospheric delay corrections corresponding to the combined effect of total electron content (TEC) at two stations forming a baseline. On the other hand, it is possible to obtain the vertical TEC (VTEC) above the VLBI antennas from VLBI data. This research intends to investigate the role of the ionospheric spatial gradient on VTEC which is derived from VLBI observations based on the latest four Continuous VLBI Campaigns (CONT08 to CONT17‐L1). For this purpose, station‐based VTEC values were computed in two modes, with and without spatial gradients. Then, these two approaches were evaluated by comparison to global ionospheric maps (GIMs). The differences between the GIM‐based VTEC values and the VLBI VTEC values derived using two parameterization approaches were used to compute the Root Mean Square Error (RMSE) for each VLBI station during the CONTs. In addition, the improvement percentages of the VLBI VTEC's error were calculated to understand the spatial gradient role. Based on the obtained results, the role of spatial gradient is more significant on the equatorial region as compared to the polar area. Using the ionospheric spatial gradient decreases the RMSE values of VLBI‐derived VTEC values from CONT08, CONT11, CONT14, and CONT17‐L1 by 26.4%, 37.6%, 32.4%, and 27.4%, respectively. In addition, it is also shown that this parameter reduces the RMSE values during the high solar activity, as in 2011 and 2014.
Creating heralded hyper-entangled photons using Rydberg atoms
Authors: Ghosh Sutapa , Rivera Nicholas , Eisenstein Gadi , Kaminer Ido 
Published: May 2021

AbstractEntangled photon pairs are a fundamental component for testing the foundations of quantum mechanics, and for modern quantum technologies such as teleportation and secured communication. Current state-of-the-art sources are based on nonlinear processes that are limited in their efficiency and wavelength tunability. This motivates the exploration of physical mechanisms for entangled photon generation, with a special interest in mechanisms that can be heralded, preferably at telecommunications wavelengths. Here we present a mechanism for the generation of heralded entangled photons from Rydberg atom cavity quantum electrodynamics (cavity QED). We propose a scheme to demonstrate the mechanism and quantify its expected performance. The heralding of the process enables non-destructive detection of the photon pairs. The entangled photons are produced by exciting a rubidium atom to a Rydberg state, from where the atom decays via two-photon emission (TPE). A Rydberg blockade helps to excite a single Rydberg excitation while the input light field is more efficiently collectively absorbed by all the atoms. The TPE rate is significantly enhanced by a designed photonic cavity, whose many resonances also translate into high-dimensional entanglement. The resulting high-dimensionally entangled photons are entangled in more than one degree of freedom: in all of their spectral components, in addition to the polarization—forming a hyper-entangled state, which is particularly interesting in high information capacity quantum communication. We characterize the photon comb states by analyzing the Hong-Ou-Mandel interference and propose proof-of-concept experiments.
Conducting double-blind placebo-controlled clinical trials of transcranial alternating current stimulation (tACS)
Authors: Frohlich Flavio , Riddle Justin 
Published: May 2021

AbstractMany psychiatric and neurological illnesses can be conceptualized as oscillopathies defined as pathological changes in brain network oscillations. We previously proposed the application of rational design for the development of non-invasive brain stimulation for the modulation and restoration of cortical oscillations as a network therapeutic. Here, we show how transcranial alternating current stimulation (tACS), which applies a weak sine-wave electric current to the scalp, may serve as a therapeutic platform for the treatment of CNS illnesses. Recently, an initial series of double-blind, placebo-controlled treatment trials of tACS have been published. Here, we first map out the conceptual underpinnings of such trials with focus on target identification, engagement, and validation. Then, we discuss practical aspects that need to be considered for successful trial execution, with particular regards to ensuring successful study blind. Finally, we briefly review the few published double-blind tACS trials and conclude with a proposed roadmap to move the field forward with the goal of moving from pilot trials to convincing efficacy studies of tACS.
Mitochondrial fission and mitophagy are independent mechanisms regulating ischemia/reperfusion injury in primary neurons
Authors: Anzell Anthony R. , Fogo Garrett M. , Gurm Zoya , Raghunayakula Sarita , Wider Joseph M. , Maheras Kathleen J. , Emaus Katlynn J. , Bryson Timothy D. , Wang Madison , Neumar Robert W. , Przyklenk Karin , Sanderson Thomas H. 
Published: May 2021

AbstractMitochondrial dynamics and mitophagy are constitutive and complex systems that ensure a healthy mitochondrial network through the segregation and subsequent degradation of damaged mitochondria. Disruption of these systems can lead to mitochondrial dysfunction and has been established as a central mechanism of ischemia/reperfusion (I/R) injury. Emerging evidence suggests that mitochondrial dynamics and mitophagy are integrated systems; however, the role of this relationship in the context of I/R injury remains unclear. To investigate this concept, we utilized primary cortical neurons isolated from the novel dual-reporter mitochondrial quality control knockin mice (C57BL/6-Gt(ROSA)26Sortm1(CAG-mCherry/GFP)Ganl/J) with conditional knockout (KO) of Drp1 to investigate changes in mitochondrial dynamics and mitophagic flux during in vitro I/R injury. Mitochondrial dynamics was quantitatively measured in an unbiased manner using a machine learning mitochondrial morphology classification system, which consisted of four different classifications: network, unbranched, swollen, and punctate. Evaluation of mitochondrial morphology and mitophagic flux in primary neurons exposed to oxygen-glucose deprivation (OGD) and reoxygenation (OGD/R) revealed extensive mitochondrial fragmentation and swelling, together with a significant upregulation in mitophagic flux. Furthermore, the primary morphology of mitochondria undergoing mitophagy was classified as punctate. Colocalization using immunofluorescence as well as western blot analysis revealed that the PINK1/Parkin pathway of mitophagy was activated following OGD/R. Conditional KO of Drp1 prevented mitochondrial fragmentation and swelling following OGD/R but did not alter mitophagic flux. These data provide novel evidence that Drp1 plays a causal role in the progression of I/R injury, but mitophagy does not require Drp1-mediated mitochondrial fission.
Heterodyne sensing of microwaves with a quantum sensor
Authors: Meinel Jonas , Vorobyov Vadim , Yavkin Boris , Dasari Durga , Sumiya Hitoshi , Onoda Shinobu , Isoya Junichi , Wrachtrup Jörg 
Published: May 2021

AbstractDiamond quantum sensors are sensitive to weak microwave magnetic fields resonant to the spin transitions. However, the spectral resolution in such protocols is ultimately limited by the sensor lifetime. Here, we demonstrate a heterodyne detection method for microwaves (MW) leading to a lifetime independent spectral resolution in the GHz range. We reference the MW signal to a local oscillator by generating the initial superposition state from a coherent source. Experimentally, we achieve a spectral resolution below 1 Hz for a 4 GHz signal far below the sensor lifetime limit of kilohertz. Furthermore, we show control over the interaction of the MW-field with the two-level system by applying dressing fields, pulsed Mollow absorption and Floquet dynamics under strong longitudinal radio frequency drive. While pulsed Mollow absorption leads to improved sensitivity, the Floquet dynamics allow robust control, independent from the system’s resonance frequency. Our work is important for future studies in sensing weak microwave signals in a wide frequency range with high spectral resolution.
Hotspot exons are common targets of splicing perturbations
Authors: Glidden David T. , Buerer Jeramiah L. , Saueressig Camillo F. , Fairbrother William G. 
Published: May 2021

AbstractHigh-throughput splicing assays have demonstrated that many exonic variants can disrupt splicing; however, splice-disrupting variants distribute non-uniformly across genes. We propose the existence of exons that are particularly susceptible to splice-disrupting variants, which we refer to as hotspot exons. Hotspot exons are also more susceptible to splicing perturbation through drug treatment and knock-down of RNA-binding proteins. We develop a classifier for exonic splice-disrupting variants and use it to infer hotspot exons. We estimate that 1400 exons in the human genome are hotspots. Using panels of splicing reporters, we demonstrate how the ability of an exon to tolerate a mutation is inversely proportional to the strength of its neighboring splice sites.
Interconversion of multiferroic domains and domain walls
Authors: Hassanpour E. , Weber M. C. , Zemp Y. , Kuerten L. , Bortis A. , Tokunaga Y. , Taguchi Y. , Tokura Y. , Cano A. , Lottermoser Th. , Fiebig M. 
Published: May 2021

AbstractSystems with long-range order like ferromagnetism or ferroelectricity exhibit uniform, yet differently oriented three-dimensional regions called domains that are separated by two-dimensional topological defects termed domain walls. A change of the ordered state across a domain wall can lead to local non-bulk physical properties such as enhanced conductance or the promotion of unusual phases. Although highly desirable, controlled transfer of these properties between the bulk and the spatially confined walls is usually not possible. Here, we demonstrate this crossover by confining multiferroic Dy0.7Tb0.3FeO3 domains into multiferroic domain walls at an identified location within a non-multiferroic environment. This process is fully reversible; an applied magnetic or electric field controls the transformation. Aside from expanding the concept of multiferroic order, such interconversion can be key to addressing antiferromagnetic domain structures and topological singularities.
Equilibrium and non-equilibrium furanose selection in the ribose isomerisation network
Authors: Dass Avinash Vicholous , Georgelin Thomas , Westall Frances , Foucher Frédéric , De Los Rios Paolo , Busiello Daniel Maria , Liang Shiling , Piazza Francesco 
Published: May 2021

AbstractThe exclusive presence of β-D-ribofuranose in nucleic acids is still a conundrum in prebiotic chemistry, given that pyranose species are substantially more stable at equilibrium. However, a precise characterisation of the relative furanose/pyranose fraction at temperatures higher than about 50 °C is still lacking. Here, we employ a combination of NMR measurements and statistical mechanics modelling to predict a population inversion between furanose and pyranose at equilibrium at high temperatures. More importantly, we show that a steady temperature gradient may steer an open isomerisation network into a non-equilibrium steady state where furanose is boosted beyond the limits set by equilibrium thermodynamics. Moreover, we demonstrate that nonequilibrium selection of furanose is maximum at optimal dissipation, as gauged by the temperature gradient and energy barriers for isomerisation. The predicted optimum is compatible with temperature drops found in hydrothermal vents associated with extremely fresh lava flows on the seafloor.
Optoelectronic mixing with high-frequency graphene transistors
Authors: Montanaro A. , Wei W. , De Fazio D. , Sassi U. , Soavi G. , Aversa P. , Ferrari A. C. , Happy H. , Legagneux P. , Pallecchi E. 
Published: May 2021

AbstractGraphene is ideally suited for optoelectronics. It offers absorption at telecom wavelengths, high-frequency operation and CMOS-compatibility. We show how high speed optoelectronic mixing can be achieved with high frequency (~20 GHz bandwidth) graphene field effect transistors (GFETs). These devices mix an electrical signal injected into the GFET gate and a modulated optical signal onto a single layer graphene (SLG) channel. The photodetection mechanism and the resulting photocurrent sign depend on the SLG Fermi level (EF). At low EF (<130 meV), a positive photocurrent is generated, while at large EF (>130 meV), a negative photobolometric current appears. This allows our devices to operate up to at least 67 GHz. Our results pave the way for GFETs optoelectronic mixers for mm-wave applications, such as telecommunications and radio/light detection and ranging (RADAR/LIDARs.)
Simulating the computational mechanisms of cognitive and behavioral psychotherapeutic interventions: insights from active inference
Authors: Smith Ryan , Moutoussis Michael , Bilek Edda 
Published: May 2021

AbstractCognitive-behavioral therapy (CBT) leverages interactions between thoughts, feelings, and behaviors. To deepen understanding of these interactions, we present a computational (active inference) model of CBT that allows formal simulations of interactions between cognitive interventions (i.e., cognitive restructuring) and behavioral interventions (i.e., exposure) in producing adaptive behavior change (i.e., reducing maladaptive avoidance behavior). Using spider phobia as a concrete example of maladaptive avoidance more generally, we show simulations indicating that when conscious beliefs about safety/danger have strong interactions with affective/behavioral outcomes, behavioral change during exposure therapy is mediated by changes in these beliefs, preventing generalization. In contrast, when these interactions are weakened, and cognitive restructuring only induces belief uncertainty (as opposed to strong safety beliefs), behavior change leads to generalized learning (i.e., “over-writing” the implicit beliefs about action-outcome mappings that directly produce avoidance). The individual is therefore equipped to face any new context, safe or dangerous, remaining in a content state without the need for avoidance behavior—increasing resilience from a CBT perspective. These results show how the same changes in behavior during CBT can be due to distinct underlying mechanisms; they predict lower rates of relapse when cognitive interventions focus on inducing uncertainty and on reducing the effects of automatic negative thoughts on behavior.
Intracellular localization of the mycobacterial stressosome complex
Authors: Ramesh Malavika , Nitharwal Ram Gopal , Behra Phani Rama Krishna , Fredrik Pettersson B. M. , Dasgupta Santanu , Kirsebom Leif A. 
Published: May 2021

AbstractMicroorganisms survive stresses by alternating the expression of genes suitable for surviving the immediate and present danger and eventually adapt to new conditions. Many bacteria have evolved a multiprotein "molecular machinery" designated the "Stressosome" that integrates different stress signals and activates alternative sigma factors for appropriate downstream responses. We and others have identified orthologs of some of the Bacillus subtilis stressosome components, RsbR, RsbS, RsbT and RsbUVW in several mycobacteria and we have previously reported mutual interactions among the stressosome components RsbR, RsbS, RsbT and RsbUVW from Mycobacterium marinum. Here we provide evidence that "STAS" domains of both RsbR and RsbS are important for establishing the interaction and thus critical for stressosome assembly. Fluorescence microscopy further suggested co-localization of RsbR and RsbS in multiprotein complexes visible as co-localized fluorescent foci distributed at scattered locations in the M. marinum cytoplasm; the number, intensity and distribution of such foci changed in cells under stressed conditions. Finally, we provide bioinformatics data that 17 (of 244) mycobacteria, which lack the RsbRST genes, carry homologs of Bacillus cereus genes rsbK and rsbM indicating the existence of alternative σF activation pathways among mycobacteria.
A study of deregulated MMR pathways and anticancer potential of curcuma derivatives using computational approach
Authors: Bhattacharya Priyanjali , Patel Trupti N. 
Published: May 2021

AbstractPlant derived products have steadily gained momentum in treatment of cancer over the past decades. Curcuma and its derivatives, in particular, have diverse medicinal properties including anticancer potential with proven safety as supported by numerous in vivo and in vitro studies. A defective Mis-Match Repair (MMR) is implicated in solid tumors but its role in haematologic malignancies is not keenly studied and the current literature suggests that it is limited. Nonetheless, there are multiple pathways interjecting the mismatch repair proteins in haematologic cancers that may have a direct or indirect implication in progression of the disease. Here, through computational analysis, we target proteins that are involved in rewiring of multiple signaling cascades via altered expression in cancer using various curcuma derivatives (Curcuma longa L.andCurcuma caesia Roxb.) which in turn, profoundly controls MMR protein function. These biomolecules were screened to identify their efficacy on selected targets (in blood-related cancers); aberrations of which adversely impacted mismatch repair machinery. The study revealed that of the 536 compounds screened, six of them may have the potential to regulate the expression of identified targets and thus revive the MMR function preventing genomic instability. These results reveal that there may be potential plant derived biomolecules that may have anticancer properties against the tumors driven by deregulated MMR-pathways.