bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of tip leakage flow unsteadiness in a transonic turbine cascade using data-driven modal decomposition methods
Authors: Yang Yi , Ma Hongwei
Published: September 2022

The evolution of tip leakage flow and subsequent vortical structures is accompanied by inherent unsteadiness. This paper presents a novel characterization for the unsteady dynamics of turbine tip flow using data-driven, i.e., equation-free modal decomposition methods, which are applied to the hybrid Reynolds-averaged Navier–Stokes/large eddy simulation data at a transonic condition. By combining these techniques, the identified eigen-tuples (eigenvalues, eigenvectors, and time evolution) are well determined, and the differences between the obtained patterns (modes) are also pronounced. The snapshot proper orthogonal decomposition (POD) analysis can isolate the large-scale fluctuating structures that populate the rear part of the suction-side, which is mainly attributed to the shock-induced vortex instability. Similar to the turbulence cascade, macro-scale coherent structures that correspond to the tip leakage vortex shedding phenomena and the subsequently transitional and noisy parts closely related to the dissipation can be well derived by a quadruple reconstruction. Three dynamic mode decomposition (DMD) variants including the amplitude selecting-DMD method, the DMD with criterion method, and the sparsity promoting (SP)-DMD method are also compared in extracting dominant modes from the periodic tip flow, and the SP-DMD method which can distill modes of broadband frequencies and low dissipation is proved to be more conducive to representing and reconstructing the complex tip flow. Additional spectral-kernel-based POD (SPOD) analysis that can identify the similar primary unsteadiness frequencies as the DMD method is also encompassed in this study. Specifically, although it manifests that a physical resemblance of the pattern of pressure fluctuations to tip eddy unsteadiness can be captured by all these approaches, the behavior of small-scale vortical interaction downstream of the trailing edge can be clearly isolated with the intrinsic Karman-type vortex layer shedding process via DMD and SPOD approaches, which also demonstrates that these two techniques are more favorable to decomposing the complex tip flows into uncoupled single-frequency coherent structures compared to the conventional POD method. On this basis, resulting modes of velocity components have been accounted for verifying their contributions to the turbulent kinetic energy fields. The ensuing observations can offer a glimpse of the complex dynamics in the tip region, which also sheds light on features previously masked by conventional analysis approaches.
Electronic state influence on selective bond breaking of core-excited nitrosyl chloride (ClNO)
Authors: Salén Peter , Schio Luca , Richter Robert , Alagia Michele , Stranges Stefano , Falcinelli Stefano , Zhaunerchyk Vitali
Published: September 2022

The potential for selective bond breaking of a small molecule was investigated with electron spectroscopy and electron–ion coincidence experiments on ClNO. The electron spectra were measured upon direct valence photoionization and resonant core excitation at the N 1s- and O 1s-edges, followed by the emission of resonant-Auger (RA) electrons. The RA spectra were analyzed with particular emphasis on the assignment of the participator and spectator states. The states are of special relevance for investigating how distinct electronic configurations influence selective bond breaking. The electron–ion coincidence measurements provided branching fractions of the produced ion fragments as a function of electron binding energy. They explicitly demonstrate how the final electronic states created after photoionization and RA decay influence fragmentation. In particular, we observed a significantly different branching fraction for spectator states compared with participator states. In addition, it was also observed that the bonds broken for the spectator states correlate with the antibonding nature of the spectator–electron orbital.
Carrier capture and emission by substitutional carbon impurities in GaN vertical diodes
Authors: Wampler W. R. , Armstrong A. M. , Vizkelethy G.
Published: September 2022

A model was developed for the operation of a GaN pn junction vertical diode which includes rate equations for carrier capture and thermally activated emission by substitutional carbon impurities and carrier generation by ionizing radiation. The model was used to simulate the effect of ionizing radiation on the charge state of carbon. These simulations predict that with no applied bias, carbon is negatively charged in the n-doped layer, thereby compensating n-doping as experimentally observed in diodes grown by metal-organic chemical vapor deposition. With reverse bias, carbon remains negative in the depletion region, i.e., compensation persists in the absence of ionization but is neutralized by exposure to ionizing radiation. This increases charge density in the depletion region, decreases the depletion width, and increases the capacitance. The predicted increase in capacitance was experimentally observed using a pulsed 70 keV electron beam as the source of ionization. In additional confirming experiments, the carbon charge-state conversion was accomplished by photoionization using sub-bandgap light or by the capture of holes under forward bias.
Numerical investigation of the flow inside a precession-driven cylindrical cavity with additional baffles using an immersed boundary method
Authors: Wilbert Mike , Giesecke André , Grauer Rainer
Published: September 2022

In this paper, we present a numerical approach to solve the Navier–Stokes equations for arbitrary vessel geometries by combining a Fourier-spectral method with a direct-forcing immersed boundary method, which one allows to consider solid–fluid interactions. The approach is applied to a paradigmatic setup motivated by the precession dynamo experiment currently under construction at Helmholtz–Zentrum Dresden–Rossendorf. The experiment consists of a fluid-filled cylinder rotating about two axes, which induces a precession-driven flow inside the cavity. The cylinder is also equipped with baffles at the end caps with adjustable penetration depth to impact the flow. The numerical details and simulation results for the spin-up and precession-driven flow in a circular cylinder with additional baffles are presented. The results provide a first confirmation that the use of such baffles in the precession dynamo experiment is a useful way of influencing the flow, allowing more efficient driving without changing the known flow structure too much.
Co-existence of bipolar nonvolatile and volatile resistive switching based on WO3 nanowire for applications in neuromorphic computing and selective memory
Authors: Qin Ling , Cheng Siqi , Xie Bingyang , Wei Xianhua , Jie Wenjing
Published: September 2022

A two-terminal memristor can be used for information memory and logic operation as well as serving as an artificial synapse for neuromorphic computing. Selective memory with some enjoyable information to be remembered and other to be screened out can be emulated by an artificial synapse. In this work, a memristor based on a single WO3 nanowire can be constructed, which demonstrates the co-existence of bipolar nonvolatile and volatile resistive switching (RS) behaviors that can be tuned by the amplitude of the operation voltage. For small operation voltages (2 V), the device demonstrates nonvolatile analog RS, which can be utilized as an artificial synapse with long- and short-term plasticity. The learning–forgetting experience of human can be emulated based on the artificial synapse. Moreover, the artificial synapse can be used for image recognition with the recognition accuracy up to 94% for small hand-written image. On the other hand, volatile RS can be observed with large operation voltages (6 V). Furthermore, based on the diverse nonvolatile and volatile RS behaviors, selective memory can be emulated. Our fabricated memristor can be used as an artificial synapse to achieve image recognition and to emulate selective memory, which paves a way to construct smart neuromorphic systems facing complex information.
Contact angle hysteresis can modulate the Newtonian rod-climbing effect
Authors: Chandra Navin Kumar , Lahiri Kaustuv , Kumar Aloke
Published: September 2022

The present work investigates the role of contact angle hysteresis at the liquid–liquid–solid interface (LLS) on the rod-climbing effect of two immiscible Newtonian liquids using experimental and numerical approaches. Experiments revealed that the final steady-state contact angle, θw, at the LLS interface varies with the rod rotation speed, ω. For the present system, θw changes from ∼69° to ∼83° when the state of the rod is changed from static condition to rotating at 3.3 Hz. With further increase in ω, the θw exceeds 90°, which cannot be observed experimentally. It is inferred from the simulations that the input value of θw saturates and attains a constant value of ∼120° for ω> 5 Hz. Using numerical simulations, we demonstrate that this contact angle hysteresis must be considered for the correct prediction of the Newtonian rod-climbing effect. Using the appropriate values of the contact angle in the boundary condition, an excellent quantitative match between the experiments and simulations is obtained in terms of the climbing height, the threshold rod rotation speed for the onset of climbing, and the shape of the liquid–liquid interface. This resolves the discrepancy between the experiments and simulations in the existing literature where a constant value of the contact angle has been used for all speeds of rod rotation.
Comparative study of titanium, platinum, and titanium nitride thin films for micro-elecrto mechanical systems (MEMS) based micro-heaters
Authors: Singh Surinder , Jejusaria Alok , Singh Jaspreet , Vashishath Munish , Kumar Dinesh
Published: September 2022

This paper presents a comparative study of titanium (Ti), platinum (Pt), and titanium nitride (TiN) micro-electro mechanical systems based micro-heaters. In the present study, a common geometry and thin film thicknesses were selected to achieve comparable base resistances for all three microheater materials. Titanium, platinum, and titanium nitride thin films are deposited using DC magnetron sputtering, E-beam evaporation, and reactive DC magnetron sputtering techniques, respectively, and deposited thicknesses were verified using scanning electron microscopy. Mechanical properties such as Young’s modulus and hardness were also evaluated using nano-indentation. Later, the micro-heaters were fabricated, packaged, and characterized. The thermal coefficient of resistance (TCR) was found to be 4146, 2641, and 487 ppm/°C for Ti, Pt, and TiN micro-heaters, respectively. Power–temperature (P–T) characterization showed that the power required to reach the set temperature is comparable for all the above micro-heater materials. The TiN micro-heater exhibits a linear voltage–current (V–I) characteristic compared to platinum and titanium micro-heaters. The temperatures measured using infra-red imaging were comparable to those calculated by TCR measurements. Furthermore, thermal stability studies have been performed on all micro-heaters for 110 h. TiN microheaters were found to be more stable and resilient to external environmental conditions than Ti and Pt microheaters because of their lower TCR values.
Ecology is more chaotic than previously thought
Authors: Hill Heather M.
Published: September 2022

About a third of species show indications of unpredictable long-term behavior.
Jamming connects granulation and flow
Authors: Middleton Christine
Published: September 2022

A unified model that describes how powders behave when they get wet could inform industrial processing of such products as ceramics and chocolate.
The effect of inter-fire interval and fire severity on seedling germination and resprouting in
Authors: Berris Karleah K. , Jones Ruby M. H. , Kok Xiangning , McCafferty Adrian K. J. , Skirrow Johannes K. , Mooney Trish
Published: September 2022

Context Regeneration from seed and resprouting are life-history strategies used by plants in fire-prone landscapes; however, for some species there is a limited understanding of how different factors influence post-fire response within populations. Aims We studied the effect of inter-fire interval and degree of tree burn on post-fire seedling germination and basal resprouting in Allocasuarina verticillata within two conservation parks on Kangaroo Island. Methods We undertook seedling counts using 1 m2 quadrats. Burnt trees were assessed for signs of resprouting. Key results Seedling density 8–9 months post-fire was primarily influenced by interfire interval, and was higher in stands with an inter-fire interval time of 37–45 years (143 per m2) compared to those with an interval of >60 years (48 per m2). Resprouting in burnt A. verticillata trees was influenced by the degree of tree burn, but also varied considerably between the two parks. Conclusions Our study confirmed that A. verticillata is a facultative seeder/resprouter that can regenerate from both seedling germination and resprouting post-fire. However, the two strategies are influenced by different factors, and resprouting rates in A. verticillata can be very low in some circumstances. Implications Because A. verticillata relies primarily on seedling germination for population persistence post-fire, it may be vulnerable to drastic changes in fire frequency. Further research is required on the minimum inter-fire interval for persistence of this species within a landscape.
More smoke today for less smoke tomorrow? We need to better understand the public health benefits and costs of prescribed fire
Authors: Jones Benjamin A. , McDermott Shana , Champ Patricia A. , Berrens Robert P.
Published: September 2022

Rapidly scaling up the use of prescribed fire is being promoted as an important pathway for reducing the growing damages of wildfire events in the United States, including limiting the health impacts from smoke emissions. However, we do not currently have the science needed to understand how the health impacts associated with prescribed fire smoke in the present compare to wildfire smoke exposure in the future. In particular, we lack an understanding of how the potential long-term public health benefits of prescribed fire on future wildfire smoke and health impacts compare to prescribed fire’s short-term effects on human health. Answering the question ‘How do we learn to sustainably coexist with wildfire?’ requires a new research agenda investigating the magnitudes and distribution of the health benefits and costs associated with prescribed burning. We suggest three areas for a new research agenda: (1) improved understanding of the health costs of prescribed fire; (2) quantification of the expected health benefits of prescribed fire through possible decreased future wildfire smoke emissions; and (3) better knowledge on the distributional impacts of prescribed fire smoke. We conclude that we need to first learn to sustainably coexist with prescribed fire in order to sustainably coexist with wildfire.
(Un)masking Seoul
Authors: Milak Eldin
Published: September 2022

In March 2019, South Korea instituted a mask mandate as the main protective measure against the spread of Covid-19. The mask and the government-issued posters detailing guidance and regulations regarding masking have since become a prominent part of Korea’s semiotic landscape. This study focuses on the capital city of Seoul to explore how these changes in the semiotic landscape have resulted in a (re)negotiation of control over space between the government and the citizens, through the lens of the mask as a static and dynamic semiotic device. The data is drawn from photographs, observations, and notes made during 3 months of commuting in central Seoul. The findings are interpreted in the light of local sociocultural ideologies, and in reference to the greater global discourse of both governmental intrusion into and regulation of spaces and behaviors through the act of mask-wearing.
Covid-19 and public responsibility
Authors: Strange Louis
Published: September 2022

This paper offers an analysis of a British government publicity campaign during the third national lockdown, which began in England in January 2021. When it came to enforcing lockdown rules, the government’s messaging in the Linguistic Landscape (LL) and elsewhere focused on individualising responsibility for the pandemic. This framing favoured the political interests of the government by apportioning blame for the highest death toll in Europe to the British public’s reckless behaviour, which conveniently elides the government’s own role in the crisis. Drawing on data from social media and the LL, I analyse the publicity campaign according to a Multimodal Critical Discourse Analysis approach, taking into account the multiple semiotic systems employed to communicate the campaign’s underlying neoliberal ideology.
Citizen Linguistic Landscape, bordering practices, and semiotic ideology in the COVID-19 pandemic
Authors: Phyak Prem , Sharma Bal Krishna
Published: September 2022

This article examines how Linguistic Landscapes in the Covid-19 pandemic construct the borders of place and people. We
build on ‘semiotic ideology’ (Keane, 2018) and ‘semiotopology’ (Peck, Stroud & Williams, 2018) to analyze the bordering practices in citizen Linguistic Landscapes
during the pandemic in Nepal. Our analysis shows that citizens combine multiple semiotic resources, both linguistic and
non-linguistic, to create physical boundaries to restrict the mobility of people during the pandemic. However, the findings show
that such practices are ideological; they promote the othering of the tenants, returnees from abroad/outside the valley, and
non-locals. We argue that keeping place and people at the centre of analysis provides a critical framework to widen the scope of
Linguistic Landscapes as a broad visual and semiotic space that embodies the bordering practices and categorization of people and
their impacts on emotions, identities, and sense of belonging.
Scaling the pandemic dispositive
Authors: Androutsopoulos Jannis
Published: September 2022

This paper uses the notions of dispositive and scale to explore the emergence and transformation of pandemic signage, focusing on a subset of regulative signs, i.e. requests to wear a mask. Based on a crowdsourced dataset of pandemic signs collected in Hamburg, analysis examines the multimodal resources sign-makers mobilize to create mask-requirement signs and the change of these signs in the transition from the first to the second pandemic wave during 2020. The findings show that regulative measures within the pandemic dispositive are scaled, i.e. given a particular spatiotemporal validity that is shaped by shifting power relations between sign producers and their audiences. This scaling is dynamically iterated as mask-wearing regulation changes its scope across pandemic waves. The rescaling of directive acts such as face-mask requests is reflected in the multimodal makeup of regulative signs, whose linguistic, pictorial, and composition choices shift as mask-wearing regulations are extended to outdoor space.
New insight into anodization of aluminium with focused ion beam pre-patterning
Authors: Roslyakov I V , Kushnir S E , Tsymbarenko D M , Sapoletova N A , Trusov L A , Napolskii K S
Published: September 2022

The self-ordered anodic aluminium oxide (AAO) structure consists of micron-scale domains—defect-free areas with a hexagonal arrangement of pores. A substantial increase in domain size is possible solely by pre-patterning the aluminium surface in the form of a defect-free hexagonal array of concaves, which guide the pore growth during subsequent anodization. Among the numerous pre-patterning techniques, direct etching by focused gallium ion beam (Ga FIB) allows the preparation of AAO with a custom-made geometry through precise control of the irradiation positions, beam energy, and ion dosage. The main drawback of the FIB approach includes gallium contamination of the aluminium surface. Here, we propose a multi-step anodizing procedure to prevent gallium incorporation into the aluminium substrate. The suggested approach successfully covers a wide range of AAO interpore distances from 100 to 500 nm. In particular, anodization of FIB pre-patterned aluminium in 0.1 M phosphoric acid at 195 V to prepare AAO with the interpore distance of about 500 nm was demonstrated for the first time. The quantification of the degree of pore ordering reveals the fraction of pores in hexagonal coordination above 96% and the in-plane mosaicity below 3° over an area of about 1000 μm2. Large-scale defect-free AAO structures are promising for creating photonic crystals and hyperbolic metamaterials with distinct functional properties.
Floating potential method using a thermionic emissive probe including an ionizing and collisional presheath
Authors: Morales Crespo R , Muñoz-Serrano E , Tejero-del-Caz A
Published: September 2022

This article studies the interaction of an argon plasma with an emissive probe considering the effect of both ionization and ion–neutral collisions. The floating potential is determined from the I–V characteristic curves as a function of the probe temperature, neutral gas pressure and plasma electron temperature. This potential increases with increasing probe temperature until reaching the plasma potential, exceeding the saturation value previously indicated by other authors. Finally, a relationship between the plasma electron temperature and the probe temperature at which the floating potential reaches the plasma potential is shown, demonstrating that these probes can be used for diagnosis of the plasma electron temperature.
Roles of the transition amplitude phases in photoelectron asymmetry of single strong attosecond pulse
Authors: Liu MingQing , Khan Shahab Ullah , Wang Xin-Qiang , Yan Pei-Guang , Jiang Wei-Chao
Published: September 2022

The angular distributions of the photoelectrons in ionization of hydrogen atom by both circularly and linearly polarized intense extreme ultraviolet (XUV) attosecond pulse are investigated by numerically solving the time-dependent Schrödinger equation. We clearly identify nonperturbative features in studying the asymmetrical photoelectron angular distributions in the polarization plane for the XUV photon energy (16.3 eV) close to the ionization threshold, while such nonperturbative features are absent for higher photon energy (36 eV) in the same pulse intensity region. In addition to the carrier-envelope phase (CEP) dependence, the ejection asymmetry of the photoelectron is also sensitive to the relative phases of transition amplitudes in absorbing one photon and two photons. As a consequence, the CEPs corresponding to the maximal (or zero) asymmetry obviously vary as the pulse intensity increases in a moderately large region from 1 × 1015 W cm−2 to 30 × 1015 W cm−2. We attribute the intensity dependence of the transition amplitude phases to a consequence of the depletion of population as well as the Stark energy shift of the initial state. We show that the relative phases of transition amplitudes can be precisely decoded from the pulse intensity dependence of the ejection asymmetry and those phases are insensitive to the ellipticity of the laser pulse.
Fe3O4/TiO2/Graphene Hybrid Nanocomposite to Improve the Lifespan of Distribution Transformers
Authors: Saravanakumar K , Samson Issac J. , Dhanaselvam J. , Rajesh R. , Singh Ajith.B. , Geetha K.
Published: September 2022

The actual lifetime of a transformer is between 30-50 years, while a foundation can be in service for 100 years. The aim of this research is to get the exact remaining lifetime of the transformers and to suggest a method to improve it. Hybrid nanoparticles are used to improve the thermal properties and dielectric strength of transformer oil. Titanium oxide (TiO2), Iron oxide (Fe3O4), and Graphene is used in specific concentration to prepare the hybrid nanoparticles. Energy Dispersive X-Ray Analysis (EDX), X-Ray Diffraction Analysis (XRD), Fourier Transform Infrared Spectroscopy (FTIR) are carried out to know whether the nanoparticles are properly synthesized. Initially Infrared thermography analysis using Fluke TiX-580 is being carried out to measure the surface temperature of the transformers and transformers under analysis are grouped. Nanofluid Transformer oil is prepared and Break Down Voltage (BDV) Test is taken to analyse the strength. Transformers are filled with nanofluid transformer oil and Infrared Thermography analysis is performed again to analyse the surface temperature. It is showing that lifetime of transformers is increased from 6 to 8% after using nanofluid transformer oil.
Non-Invasive Glucose Monitoring Using NIR Spectroscopy
Authors: Reddy Pulagam Sai Kumar , Mahesh Darapu , Uday Teja C , Janaki Muthuluri , Mannem Kiran
Published: September 2022

Diabetes Mellitus (DM), a metabolic condition, can lead to major health problems if it is not adequately treated. Traditional blood glucose monitors are intrusive and give people pain and irritation. As a result, the study’s goal was to find a non-invasive way to measure blood glucose. To determine blood glucose parameters, this system uses an NIR Spectroscopy-based system with a light source of wavelength 950nm. The light source illuminates the skin of the wrist, and a photodiode receiver captures the reflected beam. An Arduino UNO microcontroller receives the conditioned signal and digitalizes it. The spectrum is calculated by the Arduino board based on the subject’s blood glucose levels. Pre-processing and segmenting the raw waveforms are required to obtain the peaks of the NIR spectrum and to compute the regression model.
Soft Computing Techniques for Driver Alertness
Authors: Reddy Penuballi Phani Srikar , Khadyoth Gunturu Sasi Pavan , Raman Vennalakanti Sri Ganesh , Reddy Gadikota Sai Dheeraj , Valiveti Hima Bindu
Published: September 2022

There has been an alarming increase in the number of accidents that occur due to drowsiness while driving. In order to reduce roadside accidents, the detection of driver fatigue or drowsiness is crucial. Detecting fatigue during driving is crucial for reducing accidents, as well as improving the safety of both the driver and the passengers. Various methods can be used to detect drowsiness among drivers, but fuzzy logic-based detection stands out for its ability to avoid false alarms. As part of the proposed system, we are using eye-tracking in combination with methods such as Haar cascade to identify the level of drowsiness of the driver. This system has been tested in real-time.
Machine Learning approach for Software Effort Estimation using Combination of Principal Component Regression and Neural Network
Authors: Priya Varshini A G , Anitha Kumari K , Bhalavaishnavi V S , Kalpana Devi C , Pranesh S
Published: September 2022

For software projects that deploy vital tasks, it is difficult to estimate the effort of a project. In order to anticipate a few hours of labour effort (either time or personal) to deploy or maintain the software programme, software measurement points must be used. It is difficult to predict the behavior of an application that is engaged in software development during the initial phases of the effort. The hybrid model technique is used in this paper. It is necessary to apply Supervised Learning techniques in the Machine Learning algorithm. It is further subdivided into different types, such as linear regression, logistic regression, SVM (Support Vector Machine) algorithm, Naive Bayes algorithm, PCR(Principal Component Regression) algorithm, (Neural Network)NNET algorithm, KNN (K-Nearest Neighbour) algorithm, K-means, Random Forest algorithm, Dimensionality reduction algorithms, Gradient boosting algorithm, and Ada Boosting algorithm, to name a few examples. PCR algorithm and the nnet algorithm have been utilised for hybrid method, as shown above. Predictions from JM1/Software have been used to create this data collection. With 10886 unique instances and 18 unique traits, this is a very large amount. Metrics for evaluating this system include Mean Absolute Error (MAE), Mean Relative Error (MRE), Mean Magnitude of Relative Error (MMRE), Percentage of Predictive Accuracy (PRED), and R-squared. Compared to single model approaches based on machine learning algorithms techniques, the proposed hybrid using principal component regression and neural networks produced the best results, as demonstrated by the results.
Observation of well-defined Kohn-anomaly in high-quality graphene devices at room temperature
Authors: Gadelha Andreij C , Nadas Rafael , Barbosa Tiago C , Watanabe Kenji , Taniguchi Takashi , Campos Leonardo C , Raschke Markus B , Jorio Ado
Published: September 2022

Due to its ultra-thin nature, the study of graphene quantum optoelectronics, like gate-dependent graphene Raman properties, is obscured by interactions with substrates and surroundings. For instance, the use of doped silicon with a capping thermal oxide layer limited the observation to low temperatures of a well-defined Kohn-anomaly behavior, related to the breakdown of the adiabatic Born–Oppenheimer approximation. Here, we design an optoelectronic device consisting of single-layer graphene electrically contacted with thin graphite leads, seated on an atomically flat hexagonal boron nitride substrate and gated with an ultra-thin gold layer. We show that this device is optically transparent, has no background optical peaks and photoluminescence from the device components, and no generation of laser-induced electrostatic doping (photodoping). This allows for room-temperature gate-dependent Raman spectroscopy effects that have only been observed at cryogenic temperatures so far, above all the Kohn-anomaly phonon energy normalization. The new device architecture, by decoupling graphene optoelectronic properties from the substrate effects, allows for observing quantum phenomena at room temperature.
On constant-time quantum annealing and guaranteed approximations for graph optimization problems
Authors: Braida Arthur , Martiel Simon , Todinca Ioan
Published: September 2022

Quantum annealing (QA) is a computational framework where a quantum system’s continuous evolution is used to find the global minimum of an objective function over an unstructured search space. It can be seen as a general metaheuristic for optimization problems, including NP-hard ones if we allow an exponentially large running time. While QA is widely studied from a heuristic point of view, little is known about theoretical guarantees on the quality of the solutions obtained in polynomial time. In this paper, we use a technique borrowed from theoretical physics, the Lieb–Robinson (LR) bound, and develop new tools proving that short, constant-time QA guarantees constant factor approximations ratios for some optimization problems when restricted to bounded degree graphs. Informally, on bounded degree graphs the LR bound allows us to retrieve a (relaxed) locality argument, through which the approximation ratio can be deduced by studying subgraphs of bounded radius. We illustrate our tools on problems MaxCut and maximum independent set for cubic graphs, providing explicit approximation ratios and the runtimes needed to obtain them. Our results are of similar flavor to the well-known ones obtained in the different but related QAOA (quantum optimization algorithms) framework.
SPARSEMODr: Rapidly simulate spatially explicit and stochastic models of COVID-19 and other infectious diseases
Authors: Mihaljevic Joseph R , Borkovec Seth , Ratnavale Saikanth , Hocking Toby D , Banister Kelsey E , Eppinger Joseph E , Hepp Crystal , Doerry Eck
Published: September 2022

Building realistically complex models of infectious disease transmission that are relevant for informing public health is conceptually challenging and requires knowledge of coding architecture that can implement key modeling conventions. For example, many of the models built to understand COVID-19 dynamics have included stochasticity, transmission dynamics that change throughout the epidemic due to changes in host behavior or public health interventions, and spatial structures that account for important spatio-temporal heterogeneities. Here we introduce an R package, SPARSEMODr, that allows users to simulate disease models that are stochastic and spatially explicit, including a model for COVID-19 that was useful in the early phases of the epidemic. SPARSEMOD stands for SPAtial Resolution-SEnsitive Models of Outbreak Dynamics, and our goal is to demonstrate particular conventions for rapidly simulating the dynamics of more complex, spatial models of infectious disease. In this report, we outline the features and workflows of our software package that allow for user-customized simulations. We believe the example models provided in our package will be useful in educational settings, as the coding conventions are adaptable, and will help new modelers to better understand important assumptions that were built into sophisticated COVID-19 models.
The neural correlates of domain-general visual ability
Authors: McGugin Rankin W , Sunday Mackenzie A , Gauthier Isabel
Published: September 2022

People vary in their general ability to compare, identify, and remember objects. Research using latent variable modeling identifies a domain-general visual recognition ability (called o) that reflects correlations among different visual tasks and categories. We measure associations between a psychometrically-sensitive measure of o and a neurometrically-sensitive measure of visual sensitivity to shape. We report evidence for distributed neural correlates of o using functional and anatomical regions-of-interest (ROIs) as well as whole brain analyses. Neural selectivity to shape is associated with o in several regions of the ventral pathway, as well as additional foci in parietal and premotor cortex. Multivariate analyses suggest the distributed effects in ventral cortex reflect a common mechanism. The network of brain areas where neural selectivity predicts o is similar to that evoked by the most informative features for object recognition in prior work, showing convergence of 2 different approaches on identifying areas that support the best object recognition performance. Because o predicts performance across many visual tasks for both novel and familiar objects, we propose that o could predict the magnitude of neural changes in task-relevant areas following experience with specific task and object category.
Diffused calcification in a patient with long-term warfarin therapy: a case report
Authors: Sasmita Bryan Richard , Luo Suxin , Huang Bi
Published: September 2022

Background

Lifelong warfarin is mandatory in patients with mechanic valvular replacement. The main adverse effect of warfarin is haemorrhage; however, there are several rare adverse events associated with long-term warfarin treatment, such as calcification, cholesterol microembolization, and nephropathy. Here we report a case of chronic warfarin use that gradually manifested with diffused calcification.

Case summary

A 78-year-old woman received a prosthetic mechanical mitral valve replacement when she was 46 years old due to rheumatic mitral stenosis. She has been taking warfarin ever since. Ten years prior to admission, the chest radiography revealed a mild diffused calcification tracheobronchial and subsequent chest imaging indicated a progressive calcification of the tracheobronchial tree. In addition, a series of echocardiography examinations indicated progressive calcific aortic stenosis and diffused calcification in abdominal aorta. Furthermore, the patient gradually presented with advanced heart failure. Finally, she received transcatheter aortic valve replacement and the symptoms of the heart failure significantly improved.

Discussion

Currently, patients with valvular atrial fibrillation or mechanical valve replacement have no other choice for anticoagulation medication except warfarin. However, long-term use of warfarin was associated with some rare complications such as diffused calcification. Therefore, close monitoring of such side effects in patients with long-term use of warfarin is warranted.
Effect of calcium fluoride nanoparticles in prevention of demineralization during orthodontic fixed appliance treatment: a randomized clinical trial
Authors: Al Tuma Rawof R , Yassir Yassir A
Published: September 2022

Background

White spot lesions (WSLs) are the most common complications of fixed appliance orthodontic treatment.

Objectives

To evaluate the effectiveness of calcium fluoride nanoparticles-containing orthodontic primer (nCaF2-primer) in preventing the incidence of WSLs during orthodontic treatment.

Trial design

Single-centre, double-blinded, split-mouth, randomized clinical trial.

Methods

The sample involved 31 orthodontic patients (≥12 years). Participants were recruited using a simple nonstratified randomization. Data collection, measurements, and analysis were performed blindly. Outcome measures included comparing the effect of nCaF2-primer with control primer (Transbond) regarding the degree of demineralization (DIAGNOdent pen), Streptococcus mutans (S. mutans) bacterial counting [real-time polymerase chain reaction device (PCR)], and WSLs incidence (pre- and post-operative photographs). The measurements were performed before bonding, 1, 3, and 6 months after bonding and after appliance removal. A two-way repeated measure analysis of variance test (for DIAGNOdent pen scores), and Wilcoxon signed-rank test (for the difference between bacterial counting and WSLs incidence) were used (P < 0.05).

Results

Thirty-one patients were recruited and randomized (mean age 17.9 ± 2.45 years). For the primary outcome (DIAGNOdent pen scores) and secondary outcome of S. mutans counting: 31 patients (310 teeth for each group) were included in scoring at T1 and T3, and 30 patients (300 teeth) were included at T6. While for the photographic scores, 26 patients were included after bracket bonding. The demineralization scores showed significant differences at all-time intervals within the 6 months after bracket bonding which was more noticeable after the first month. There was a significant difference in bacterial count between the two primer groups at the T1 only. Regarding photographic scores, there were no significant differences in the WSLs incidence between the two primers groups after brackets removal. No harm was detected during treatment, except the usual pain/gingival irritation.

Conclusions

nCaF2-primer effectively decreased demineralization scores within the 6 months after bracket bonding. Moreover, it significantly reduced S. mutans colonization after the first month. However, the tested primer did not have an extra advantage in preventing WSLs development at the clinical level after appliance removal.

Trial registration

The trial was registered with ClinicalTrials.gov on 8 May 2021 (registration number: NCT04994314).
Reduction in blood pressure for elevated blood pressure/stage 1 hypertension according to the American College of Cardiology/American Heart Association guideline and cardiovascular outcomes
Authors: Kaneko Hidehiro , Yano Yuichiro , Suzuki Yuta , Okada Akira , Itoh Hidetaka , Matsuoka Satoshi , Fujiu Katsuhito , Michihata Nobuaki , Jo Taisuke , Takeda Norifumi , Morita Hiroyuki , Node Koichi , Viera Anthony J , Lima Joao A C , Oparil Suzanne , Lam Carolyn S P , Carey Robert M , Yasunaga Hideo , Komuro Issei
Published: September 2022

Aims

Few studies have examined the relationship of blood pressure (BP) change in adults with elevated BP or stage 1 hypertension according to the American College of Cardiology (ACC)/American Heart Association (AHA) guideline with cardiovascular outcomes. We sought to identify the effect of BP change among individuals with elevated BP or stage 1 hypertension on incident heart failure (HF) and other cardiovascular diseases (CVDs).

Methods and results

We conducted a retrospective cohort study including 616 483 individuals (median age 46 years, 73.7% men) with elevated BP or stage 1 hypertension based on the ACC/AHA BP guideline. Participants were categorized using BP classification at one-year as normal BP (n = 173 558), elevated BP/stage 1 hypertension (n = 367 454), or stage 2 hypertension (n = 75 471). The primary outcome was HF, and the secondary outcomes included (separately) myocardial infarction (MI), angina pectoris (AP), and stroke. Over a mean follow-up of 1097 ± 908 days, 10 544 HFs, 1317 MIs, 11 070 APs, and 5198 strokes were recorded. Compared with elevated BP/stage 1 hypertension at one-year, normal BP at one-year was associated with a lower risk of developing HF [hazard ratio (HR): 0.89, 95% CI:0.85–0.94], whereas stage 2 hypertension at one-year was associated with an elevated risk of developing HF (HR:1.43, 95% CI:1.36–1.51). This association was also present in other cardiovascular outcomes including MI, AP, and stroke. The relationship was consistent in all subgroups stratified by age, sex, baseline BP category, and overweight/obesity.

Conclusion

A one-year decline in BP was associated with the lower risk of HF, MI, AP, and stroke, suggesting the importance of lowering BP in individuals with elevated BP or stage 1 hypertension according to the ACC/AHA guideline to prevent the risk of developing CVD.
Tooth Loss, Periodontal Disease, and Mild Cognitive Impairment Among Hispanic/Latino Immigrants: The Moderating Effects of Age at Immigration
Authors: Luo Huabin , Wu Bei , González Hector M , Stickel Ariana , Kaste Linda M , Tarraf Wassim , Daviglus Martha L , Sanders Anne E , Cai Jianwen
Published: September 2022

Background

The objectives were to assess (a) the association between poor oral health and mild cognitive impairment (MCI) in Hispanic/Latino immigrants and (b) potential modification effects on this association by age at immigration.

Methods

Data were from the Hispanic Community Health Study/Study of Latinos and its ancillary study—the Study of Latinos–Investigation of Neurocognitive Aging. MCI, a binary outcome variable, defined by the National Institute on Aging-Alzheimer’s Association criteria. The main exposure was significant tooth loss (STL), defined as a loss of 8 or more teeth, and periodontitis, classified using the Centers for Disease Control and Prevention and American Academy of Periodontology case classification. Multiple logistic regression was used to assess the association between STL/periodontitis and MCI and test moderation effects of age at immigration. The analytical sample comprised 5 709 Hispanic/Latino adult immigrants.

Results

Hispanic/Latino immigrants with STL (adjusted odds ratio [AOR] = 1.36, 95% confidence interval [CI]: 1.01–1.85) were more likely to have MCI than those with greater tooth retention. Overall, migration to the United States after age 18 was associated with greater odds of MCI than migration at a younger age. A significant interaction effect between STL and age at immigration revealed that the effect of STL on MCI is even higher in those who immigrated to the United States at ages 35–49 years.

Conclusions

STL is a significant risk factor for MCI and age at immigration had a modification effect on the association between STL and MCI. Better access to dental care, health education on risk factors of MCI, and promotion of good oral health may mitigate the burden of cognitive impairment in Hispanics/Latinos.
A high-resolution microseismic source location method based on contrast source algorithm
Authors: Wei Shuying , Chen Xiaohong , Li Jingye , Ma Jitao , Huang Guangtan
Published: September 2022

Passive source location estimation technology plays an extremely important role in microseismic monitoring. However, the energy of microseismic signals is generally weak and prone to be interrupted as noise, which will affect the detection and location accuracy of microseismic events. Besides, the existing wave-equation-based source location estimation methods are not suitable for strongly heterogeneous strata, such as faults, salt bodies, fractures filled with proppant and other fluids, etc. These complex geological structures often trigger scattered waves. Thus, based on scattering theory, a high-resolution microseismic source location estimation method with a new grouping imaging condition is proposed by implementing a contrast source numerical simulation method in the process of wavefield backpropagation. First, the contrast source algorithm is used to perform wavefield extrapolation by solving the Helmholtz equation in the frequency domain, which can provide more comprehensive, effective information to get high-precision locations. Moreover, an optimized grouping imaging condition is proposed, which can improve the imaging resolution and computational efficiency. The effectiveness of the method we propose is illustrated using numerical examples. Compared with traditional source location estimation methods, including with low signal-to-noise ratio or multisource location estimation, this method results in strong energy focusing achieved in an effecient manner.
Simple and practical sialoglycan encoding system reveals vast diversity in nature and identifies a universal sialoglycan-recognizing probe derived from AB5 toxin B subunits
Authors: Sasmal Aniruddha , Khan Naazneen , Khedri Zahra , Kellman Benjamin P , Srivastava Saurabh , Verhagen Andrea , Yu Hai , Bruntse Anders Bech , Diaz Sandra , Varki Nissi , Beddoe Travis , Paton Adrienne W , Paton James C , Chen Xi , Lewis Nathan E , Varki Ajit
Published: September 2022

Vertebrate sialic acids (Sias) display much diversity in modifications, linkages, and underlying glycans. Slide microarrays allow high-throughput explorations of sialoglycan–protein interactions. A microarray presenting ~150 structurally defined sialyltrisaccharides with various Sias linkages and modifications still poses challenges in planning, data sorting, visualization, and analysis. To address these issues, we devised a simple 9-digit code for sialyltrisaccharides with terminal Sias and underlying two monosaccharides assigned from the nonreducing end, with 3 digits assigning a monosaccharide, its modifications, and linkage. Calculations based on the encoding system reveal >113,000 likely linear sialyltrisaccharides in nature. Notably, a biantennary N-glycan with 2 terminal sialyltrisaccharides could thus have >1010 potential combinations and a triantennary N-glycan with 3 terminal sequences, >1015 potential combinations. While all possibilities likely do not exist in nature, sialoglycans encode enormous diversity. While glycomic approaches are used to probe such diverse sialomes, naturally occurring bacterial AB5 toxin B subunits are simpler tools to track the dynamic sialome in biological systems. Sialoglycan microarray was utilized to compare sialoglycan-recognizing bacterial toxin B subunits. Unlike the poor correlation between B subunits and species phylogeny, there is stronger correlation with Sia-epitope preferences. Further supporting this pattern, we report a B subunit (YenB) from Yersinia enterocolitica (broad host range) recognizing almost all sialoglycans in the microarray, including 4-O-acetylated-Sias not recognized by a Yersinia pestis orthologue (YpeB). Differential Sia-binding patterns were also observed with phylogenetically related B subunits from Escherichia coli (SubB), Salmonella Typhi (PltB), Salmonella Typhimurium (ArtB), extra-intestinal E.coli (EcPltB), Vibrio cholera (CtxB), and cholera family homologue of E. coli (EcxB).
Jones v Kernott [2011] UKSC 53, Supreme Court
Authors: Nair Aruna
Published: September 2022

Essential Cases: Land Law provides a bridge between course textbooks and key case judgments. This case document summarizes the facts and decision in Jones v Kernott [2011] UKSC 53, Supreme Court. The document also includes supporting commentary from author Aruna Nair.
Ashburn Anstalt v WJ Arnold & Co. Ltd [1989] Ch 1, Court of Appeal
Authors: Nair Aruna
Published: September 2022

Essential Cases: Land Law provides a bridge between course textbooks and key case judgments. This case document summarizes the facts and decision in Ashburn Anstalt v WJ Arnold & Co. Ltd [1989] Ch 1, Court of Appeal. The document also includes supporting commentary from author Aruna Nair.