bluuebunny/crossref_metadata_2025 huggingface dataset:
Capacitor Detection on PCB Using AdaBoost Classifier
Authors: Fang Jian , Shang Lina , Gao Guangchun , Xiong Kai , Zhang Cui
Published: September 2020

In PCB manufacturing, automatic optical inspection (AOI) is a key technology to improve production efficiency and quality. At present, most of the AOI algorithms are aimed at PCB and SMD components. An AOI algorithm for plug-in polar capacitors is proposed in this paper. The algorithm mainly uses AdaBoost classifier based on Haar-like feature to realize the recognition of plug-in capacitors. The polarity of the capacitor is detected by comparing the image features of the target capacitor. Experimental results show that the algorithm proposed in this paper can effectively detect two kinds of defects: capacitor missing and capacitor polarity opposite. The algorithm can be applied to the AOI detection of PCB before and after wave soldering.
Single-frequency, pulsed Yb3+-doped multicomponent phosphate power fiber amplifier
Authors: Balliu Enkeleda , Boetti Nadia G , Pugliese Diego , Lousteau Joris , Engholm Magnus , Milanese Daniel , Nilsson Hans-Erik
Published: September 2020

High-power, single-frequency, pulsed fiber amplifiers are required in light detection and ranging, coherent laser detection, and remote sensing applications to reach long range within a short acquisition time. However, the power-scaling of these amplifiers is limited by nonlinearities generated in the optical fibers, in particular by stimulated Brillouin scattering (SBS). In this regard, the use of multicomponent phosphate glasses maximizes the energy extraction and minimizes nonlinearities. Here, we present the development of a single-stage, hybrid, pulsed fiber amplifier using a custom-made multicomponent Yb-doped phosphate fiber. The performance of the phosphate fiber was compared to a commercial Yb-doped silica fiber. While the latter showed SBS limitation at nearly 6.5 kW for 40 cm length, the maximum achieved output peak power for the multicomponent Yb-doped phosphate fiber was 11.7 kW for 9 ns pulses using only 20 cm with no sign of SBS.
Diversiform propagation of hollow Gaussian beam clusters in non-linear media with self-induced parabolic potentials
Authors: Song Limin , Yang Zhenjun , Guo Jianli , Du Boyue , Pang Zhaoguang
Published: September 2020

We report the diversiform propagation of hollow Gaussian beam clusters in non-linear media with self-induced parabolic potentials. It is found that the beam cluster can present various periodically varying propagation forms by tuning the initial incident conditions. We roughly classify the initial incident cases into five types—parallel incidence, spiraling incidence, convergent incidence, divergent incidence, and mixed incidence—ground on the introduced transverse velocity parameter. The propagation characteristics, such as the evolutions of the intensity patterns, the projection trajectories, the rotating angle, the angular velocity, the center distance, the size and the phase distribution of the beam cluster, are illustrated graphically in detail. These novel forms of beam clusters presented in this paper possess complicated and unique spatial distribution and controllable propagation parameters for their potential applications in all-optical networks, optical switch, optical tweezers, multi-particle trapping, and other related fields.
Effect of ultrathin palladium layer in achieving a low temperature and pressure wafer level aluminum to aluminum bonding
Authors: Cheemalamarri Hemanth Kumar , Bonam Satish , Vanjari Siva Rama Krishna , Singh Shiv Govind
Published: September 2020

Metal-Metal diffusion bonding was reassuring for micro electro mechanical system (MEMS) packaging and three dimensional (3D) integration. Despite copper and gold, aluminum (Al) is also proficient for wafer-level bonding due to its CMOS compatibility. As of now, a successful bonding reported with a temperature requirement is >300 °C, due to chemically unwavering surface oxide on the aluminum surface. In this work, a facile method of successful Al–Al bonding at a low temperature and pressure by passivating Al surface with another ultrathin noble metal has been reported. Here, a systematic study for selecting a required optimum ultrathin passivation layer thickness in making the surface to be free from surface oxide formation is provided. Also, looking over in an enhancement of surface morphology and microstructure by varying the thickness of an ultrathin passivation layer. Added to this, after obtaining the required oxide-free surface, we conducted wafer-level thermo-compression bonding for optimizing low temperature (∼250 °C) and pressure (∼3 MPa) by inspecting interface quality and reliability studies. We put forward that the proposed bonding technique is promising to use at the wafer-level, to integrate high-performance chip stack interconnects and facile packaging methods for micro-electro-mechanical systems.
Structural and optical characterization of pure and SnZrO3 doped PS based polymer nanocomposite
Authors: Hussen Sarkawt A
Published: September 2020

This report presents a straightforward, an efficient and a promising methodology for the preparation of nanocomposite polymer (NCP) systems composed of polystyrene (PS) as the host polymer with addition of SnZrO3 filler. For structural study and optical properties determination of the prepared samples; x-ray diffraction (XRD), and ultraviolet-visible (UV–vis) spectroscopy was performed, respectively. From XRD pattern several new peaks of the composites appearance as an evidence of strong interaction between the polymer matrix and the filler. The crystalline size of nan-particles were estimated using Debye–Scherrer’s equation. The fundamental optical parameters, for instance refractive index (n), optical band gap energy (E

g
), optical dielectric loss (ε

i
), and optical dielectric constant (ε

r
) have been determined in which the quantity of SnZrO3 is effective. Tauc’s equation has been used in the specifying the direct and indirect band gap energy. The absorption edge (Ea) shifting from4.42 to 3.74 eV is associated to the charge-transfer complexes creation within the composite films. There is an increasing in the n from 1.2 to 2.54 for pure PS upon addition of 12 wt.% doped that indicates the existence of few interaction between photons and electrons. The optical band gap and transition type are studied in detail. The exponent value (

r

) has been identified from Tauc’s equation using the ε
i against photon energy to measure optical band gap energy and specify the electronic transition types. This doping of filler has considerably increased the ε
r from (1.5–6.4) for pure PS sample and doped SnZrO3 nanoparticles.
Toward controlled thermoelectric properties of Pb and Sb co-doped nanostructured Thallium Telluride for energy applications
Authors: Khan Waqas Muhammad , Rahman Altaf Ur , Tufail Muhammad , Ibrar Muhammad , Shah Wiqar Hussain , Syed Waqar Adil , Gul Banat
Published: September 2020

Here, the structure-dependent electronic, thermal, and transport properties of nanostructured thallium telluride (Tl8Pb
x
Sb2−x
Te6) through controlled variation in Pb and Sb (x = 1.96, 1.97, 1.98, 1.99) concentrations have been investigated. In the temperature and concentration-dependent electrical conductivity measurements, the highest electrical conductivity 131.96 × 103

Ω

−
1

m

−
1

at 300 K was measured for x = 1.99 and the maximum observed Seebeck value for the optimized Tl8Pb1.96Sb0.04Te6 nanoparticles was 110.7 μV/K at 550 K. Such an increased value of the Seebeck coefficient led to the achievement of a significantly improved high-power factor, which was found to be increasing with temperature and decreasing with the increase of Pb concentration. The density functional theory calculations performed for Pb and Sb co-doped Tl5Te3 resulted in the enhanced σ

e
and S with a significant reduction in electronic thermal conductivity (κ

e
) and is found consistent with experimentally measured κ

e
. The highest ZT = 0.35 and 0.18 were recorded experimentally and theoretically for Pb and Sb co-doped in Tl5Te3 nanoparticles.
Two-fold symmetry of in-plane magnetoresistance anisotropy in the superconducting states of BiCh2-based LaO0.9F0.1BiSSe single crystal
Authors: Hoshi Kazuhisa , Kimata Motoi , Goto Yosuke , Miura Akira , Moriyoshi Chikako , Kuroiwa Yoshihiro , Nagao Masanori , Mizuguchi Yoshikazu
Published: September 2020

Recently, two-fold symmetric in-plane anisotropy of the superconducting properties have been observed in a single crystal of BiCh2-based (Ch: S, Se) layered superconductor LaO0.5F0.5BiSSe having a tetragonal (four-fold-symmetric) in-plane structure; the phenomena are very similar to those observed in nematic superconductors. To explore the origin of the two-fold symmetric anisotropy in the BiCh2-based system, we have investigated the electron-doping dependence on the anisotropy by examining the in-plane anisotropy of the magnetoresistance in the superconducting states for a single crystal of LaO0.9F0.1BiSSe under high magnetic fields up to 15 T. We observed a two-fold symmetry of in-plane anisotropy of magnetoresistance for LaO0.9F0.1BiSSe. The results obtained for LaO0.9F0.1BiSSe are quite similar to those observed for LaO0.5F0.5BiSSe, which has a higher electron doping concentration than LaO0.9F0.1BiSSe. Our present finding suggests that the emergence of the in-plane symmetry breaking in the superconducting state is robust to the carrier concentration in the series of LaO1−x
F
x
BiSSe.
Modern Brazil: A Very Short Introduction
Authors: Pereira Anthony W.
Published: September 2020

Modern Brazil: A Very Short Introduction provides an account of modern Brazil, covering some of the major features of the country’s transformation. Brazil is alternately praised as a rising power or written off as a country forever failing to reach its potential. This VSI discusses the rise of the modern state in the mid-20th century, and the domestic economic, political, and social challenges faced by the country today. Highlighting some of the peculiar features of Brazil’s development, it also examines how its political leaders engage in informal political deals. Moreover, it looks at the state’s welfare institutions and Brazil’s long history of peaceful relations with neighbours.
Socialism: A Very Short Introduction
Authors: Newman Michael
Published: September 2020

Socialism: A Very Short Introduction looks at the history of socialism and its contemporary relevance. Is socialism an outdated ideology today? This VSI provides an overview of socialism’s origins, its relationships to communism and social democracy, its different manifestations around the world and throughout history, and its intersections with issues of ethnicity and gender. Examples of the practical implementation of socialist values are provided by case studies of social democracy in Sweden and communism in Cuba. The rise of the ‘New Left’ midway through the 20th century included feminist and green movements, followed up by radical anti-capitalist and climate justice protests and political movements.
Ovid: A Very Short Introduction
Authors: Morgan Llewelyn
Published: September 2020

Ovid: A Very Short Introduction discusses Ovid’s poetry, and the social and cultural context in which it was written. No poet of the Graeco-Roman world has had a deeper impact on subsequent literature and art than Ovid. But he was also a man of his time, and while the poetry he wrote still speaks to us today, it channels the cultural and political upheavals that Rome in his day was experiencing: its public life under Rome’s first emperor Augustus, changing sexual mores, religion, literary debt to Greece, and urban landscape. This VSI introduces Ovid’s poetry on love, heroic women, metamorphosis, Roman festivals, and his own exile by Augustus. It also explores his immense influence on later literature and art, an uninterrupted popularity through the Middle Ages and into modern times. Artists as diverse as Chaucer, Goethe, and Dali are all his heirs. But it focuses on his own poetry. Ovid was the wittiest, most inventive, and least deferential of Roman poets, his poetry a scintillating combination of high intellect and mischief.
Identifiers.org: Compact Identifier services in the cloud
Authors: Bernal-Llinares Manuel , Ferrer-Gómez Javier , Juty Nick , Goble Carole , Wimalaratne Sarala M , Hermjakob Henning
Published: September 2020

Motivation

Since its launch in 2010, Identifiers.org has become an important tool for the annotation and cross-referencing of Life Science data. In 2016, we established the Compact Identifier (CID) scheme (prefix: accession) to generate globally unique identifiers for data resources using their locally assigned accession identifiers. Since then, we have developed and improved services to support the growing need to create, reference and resolve CIDs, in systems ranging from human readable text to cloud-based e-infrastructures, by providing high availability and low-latency cloud-based services, backed by a high-quality, manually curated resource.

Results

We describe a set of services that can be used to construct and resolve CIDs in Life Sciences and beyond. We have developed a new front end for accessing the Identifiers.org registry data and APIs to simplify integration of Identifiers.org CID services with third-party applications. We have also deployed the new Identifiers.org infrastructure in a commercial cloud environment, bringing our services closer to the data.

Availabilityand implementation

https://identifiers.org.
HOPS: high-performance library for (non-)uniform sampling of convex-constrained models
Authors: Jadebeck Johann F , Theorell Axel , Leweke Samuel , Nöh Katharina
Published: September 2020

The C++ library Highly Optimized Polytope Sampling (HOPS) provides implementations of efficient and scalable algorithms for sampling convex-constrained models that are equipped with arbitrary target functions. For uniform sampling, substantial performance gains were achieved compared to the state-of-the-art. The ease of integration and utility of non-uniform sampling is showcased in a Bayesian inference setting, demonstrating how HOPS interoperates with third-party software.

Availability and implementation

Source code is available at https://github.com/modsim/hops/, tested on Linux and MS Windows, includes unit tests, detailed documentation, example applications and a Dockerfile.

Supplementary information

Supplementary data are available at Bioinformatics online.
Birth order as a source of within-genotype diversification in the clonal duckweed,Spirodela polyrhiza(Araceae: Lemnoideae)
Authors: Morris Riley S , Compton Mary E , Simons Andrew M
Published: September 2020

Organismal persistence attests to adaptive responses to environmental variation. Diversification bet hedging, in which risk is reduced at the cost of expected fitness, is increasingly recognized as an adaptive response, yet mechanisms by which a single genotype generates diversification remain obscure. The clonal greater duckweed, Spirodela polyrhiza (L.), facultatively expresses a seed-like but vegetative form, the ‘turion’, that allows survival through otherwise lethal conditions. Turion reactivation phenology is a key fitness component, yet little is known about turion reactivation phenology in the field, or sources of variation. Here, using floating traps deployed in the field, we found a remarkable extent of variation in natural reactivation phenology that could not be explained solely by spring cues, occurring over a period of ≥ 200 days. In controlled laboratory conditions, we found support for the hypothesis that turion phenology is influenced jointly by phenotypic plasticity to temperature and diversification within clones. Turion ‘birth order’ consistently accounted for a difference in reactivation time of 46 days at temperatures between 10 and 18 °C, with turions early in birth order reactivating more rapidly than turions late in birth order. These results should motivate future work to evaluate the variance in turion phenology formally as a bet-hedging trait.
Differential exposure and susceptibility to threats based on evolutionary history: how OCBIL theory informs flora conservation
Authors: Gosper Carl R , Kinloch Janine , Coates David J , Byrne Margaret , Pitt Georgie , Yates Colin J
Published: September 2020

Optimal conservation approaches have been proposed to differ for biota with contrasting evolutionary histories. Natural selection filters the distribution of plant traits over evolutionary time, with the current expression of traits mediating susceptibility to contemporary and often novel threats. We use old, climatically buffered, infertile landscape (OCBIL) theory to compile predictions regarding differences in exposure and susceptibility to key threats between OCBIL and young, often disturbed, fertile landscape (YODFEL) flora. Based on literature and existing data from the Southwest Australian Floristic Region (SWAFR), we evaluate evidence in support of our predictions, finding strong theoretical and empirical support for the proposition that exposure and/or impact of many threats differs between OCBILs and YODFELs. OCBILs have more exposure to land clearance from mining, whereas many YODFELs have greater exposure to land clearance from agriculture, and urban and industrial land uses, and greater overall levels of habitat loss and fragmentation. OCBIL flora are more susceptible to pathogens and extremes of fire interval than YODFEL flora, but conversely may have a greater capacity to persist in smaller populations if small populations featured in the evolutionary history of the species prior to anthropogenic fragmentation, and have substantial resistance to weed invasion. We argue that consideration of evolutionary history has an important role in informing conservation management.
Altered skeletal muscle glucose-fatty acid flux in amyotrophic lateral sclerosis
Authors: Steyn Frederik J , Li Rui , Kirk Siobhan E , Tefera Tesfaye W , Xie Teresa Y , Tracey Timothy J , Kelk Dean , Wimberger Elyse , Garton Fleur C , Roberts Llion , Chapman Sarah E , Coombes Jeff S , Leevy W Matthew , Ferri Alberto , Valle Cristiana , René Frédérique , Loeffler Jean-Philippe , McCombe Pamela A , Henderson Robert D , Ngo Shyuan T
Published: September 2020

Amyotrophic lateral sclerosis is characterized by the degeneration of upper and lower motor neurons, yet an increasing number of studies in both mouse models and patients with amyotrophic lateral sclerosis suggest that altered metabolic homeostasis is also a feature of disease. Pre-clinical and clinical studies have shown that modulation of energy balance can be beneficial in amyotrophic lateral sclerosis. However, the capacity to target specific metabolic pathways or mechanisms requires detailed understanding of metabolic dysregulation in amyotrophic lateral sclerosis. Here, using the SOD1G93A mouse model of amyotrophic lateral sclerosis, we demonstrate that an increase in whole-body metabolism occurs at a time when glycolytic muscle exhibits an increased dependence on fatty acid oxidation. Using myotubes derived from muscle of amyotrophic lateral sclerosis patients, we also show that increased dependence on fatty acid oxidation is associated with increased whole-body energy expenditure. In the present study, increased fatty acid oxidation was associated with slower disease progression. However, within the patient cohort there was considerable heterogeneity in whole-body metabolism and fuel oxidation profiles. Thus, future studies that decipher specific metabolic changes at an individual patient level are essential for the development of treatments that aim to target metabolic pathways in amyotrophic lateral sclerosis.
Risk Factors for In-hospital Mortality from Coronavirus Disease 2019 Infection Among Black Patients—An Urban Center Experience
Authors: Bhargava Ashish , Sharma Mamta , Riederer Kathleen , Fukushima Elisa Akagi , Szpunar Susanna M , Saravolatz Louis
Published: September 2020

Background

Racial disparities are central in the national conversation about coronavirus disease 2019 (COVID-19) , with Black/African Americans being disproportionately affected. We assessed risk factors for death from COVID-19 among Black inpatients at an urban hospital in Detroit, Michigan.

Methods

This was a retrospective, single-center cohort study. We reviewed the electronic medical records of patients positive for severe acute respiratory syndrome coronavirus 2 (the COVID-19 virus) on qualitative polymerase chain reaction assay who were admitted between 8 March 2020 and 6 May 2020. The primary outcome was in-hospital mortality.

Results

The case fatality rate was 29.1% (122/419). The mean duration of symptoms prior to hospitalization was 5.3 (3.9) days. The incidence of altered mental status on presentation was higher among patients who died than those who survived, 43% vs 20.0%, respectively (P < .0001). From multivariable analysis, the odds of death increased with age (≥60 years), admission from a nursing facility, Charlson score, altered mental status, higher C-reactive protein on admission, need for mechanical ventilation, presence of shock, and acute respiratory distress syndrome.

Conclusions

These demographic, clinical, and laboratory factors may help healthcare providers identify Black patients at highest risk for severe COVID-19–associated outcomes. Early and aggressive interventions among this at-risk population may help mitigate adverse outcomes.
Emerging RNA-Dependent RNA Polymerase Mutation in a Remdesivir-Treated B-cell Immunodeficient Patient With Protracted Coronavirus Disease 2019
Authors: Martinot Martin , Jary Aude , Fafi-Kremer Samira , Leducq Valentin , Delagreverie Heloise , Garnier Marc , Pacanowski Jérôme , Mékinian Arsène , Pirenne France , Tiberghien Pierre , Calvez Vincent , Humbrecht Catherine , Marcelin Anne-Geneviève , Lacombe Karine
Published: September 2020

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a newly discovered virus for which remdesivir is the only antiviral available. We report the occurrence of a mutation in RdRP (D484Y) following treatment with remdesivir in a 76-year-old female with post-rituximab B-cell immunodeficiency and persistent SARS-CoV-2 viremia. A cure was achieved after supplementation with convalescent plasma.
Assessment of long-term outcomes: aortic valve reimplantation versus aortic valve and root replacement with biological valved conduit in aortic root aneurysm with tricuspid valve
Authors: Yamabe Tsuyoshi , Zhao Yanling , Kurlansky Paul A , Nitta Suzuka , Borger Michael A , George Isaac , Smith Craig R , Takayama Hiroo
Published: September 2020

OBJECTIVES

We compared the long-term outcomes between aortic valve reimplantation [David V (DV)] and aortic valve and root replacement with biological valved conduit [Bentall–De Bono (BD)] for the patients with aortic root aneurysm with tricuspid valve.

METHODS

Among 876 patients who underwent aortic root replacement in our institution between 2005 and 2018, 371 patients who underwent DV (n = 199) or BD (n = 172) for aortic root aneurysm with tricuspid valve were retrospectively reviewed. Exclusion criteria included aortic stenosis, infective endocarditis, previous prosthetic aortic valve, bicuspid aortic valve, aortic dissection and mechanical Bentall procedure. Propensity score matching was performed based on the patient characteristics, matching 90 patients in each group. The primary end point was all-cause mortality. Secondary end points were reoperation for any cause and specifically for aortic valve-related cause.

RESULTS

After propensity score matching, DV and BD groups each had 1 in-hospital mortality (1.1%). Survival at 10 years was 95.3% [95% confidence interval (CI) 85.8–98.5] in DV and 98.6% (95% CI 90.8–99.8) in BD (P = 0.345). The cumulative incidences of reoperation at 10 years in DV versus BD were 3.9% (95% CI 0.7–11.8) vs 18.1% (95% CI 6.9–33.4) for any cause (P = 0.046) and 1.9% (95% CI 0.1–8.8) vs 15.9% (95% CI 5.5–31.4) for aortic valve-related causes (P = 0.032). The reasons for valve-related reoperation were aortic insufficiency (3/5 in DV vs 5/10 in BD), aortic stenosis (0/5 vs 2/10) and infective endocarditis (2/5 vs 3/10).

CONCLUSIONS

Both DV and BD procedures for patients with aortic root aneurysm with tricuspid valve resulted in excellent 10-year survival. All-cause and aortic valve-related reoperations were significantly less frequent with valve-sparing root replacement, suggesting an advantage of DV over biological BD.
Valve Academic Research Consortium 3: updated endpoint definitions for aortic valve clinical research
Authors:   VARC-3 WRITING COMMITTEE, Généreux Philippe , Piazza Nicolo , Alu Maria C , Nazif Tamim , Hahn Rebecca T , Pibarot Philippe , Bax Jeroen J , Leipsic Jonathon A , Blanke Philipp , Blackstone Eugene H , Finn Matthew T , Kapadia Samir , Linke Axel , Mack Michael J , Makkar Raj , Mehran Roxana , Popma Jeffrey J , Reardon Michael , Rodes-Cabau Josep , Van Mieghem Nicolas M , Webb John G , Cohen David J , Leon Martin B
Published: September 2020

Aims 

The Valve Academic Research Consortium (VARC), founded in 2010, was intended to (i) identify appropriate clinical endpoints and (ii) standardize definitions of these endpoints for transcatheter and surgical aortic valve clinical trials. Rapid evolution of the field, including the emergence of new complications, expanding clinical indications, and novel therapy strategies have mandated further refinement and expansion of these definitions to ensure clinical relevance. This document provides an update of the most appropriate clinical endpoint definitions to be used in the conduct of transcatheter and surgical aortic valve clinical research.

Methods and results 

Several years after the publication of the VARC-2 manuscript, an in-person meeting was held involving over 50 independent clinical experts representing several professional societies, academic research organizations, the US Food and Drug Administration (FDA), and industry representatives to (i) evaluate utilization of VARC endpoint definitions in clinical research, (ii) discuss the scope of this focused update, and (iii) review and revise specific clinical endpoint definitions. A writing committee of independent experts was convened and subsequently met to further address outstanding issues. There were ongoing discussions with FDA and many experts to develop a new classification schema for bioprosthetic valve dysfunction and failure. Overall, this multi-disciplinary process has resulted in important recommendations for data reporting, clinical research methods, and updated endpoint definitions. New definitions or modifications of existing definitions are being proposed for repeat hospitalizations, access site-related complications, bleeding events, conduction disturbances, cardiac structural complications, and bioprosthetic valve dysfunction and failure (including valve leaflet thickening and thrombosis). A more granular 5-class grading scheme for paravalvular regurgitation (PVR) is being proposed to help refine the assessment of PVR. Finally, more specific recommendations on quality-of-life assessments have been included, which have been targeted to specific clinical study designs.

Conclusions 

Acknowledging the dynamic and evolving nature of less-invasive aortic valve therapies, further refinements of clinical research processes are required. The adoption of these updated and newly proposed VARC-3 endpoints and definitions will ensure homogenous event reporting, accurate adjudication, and appropriate comparisons of clinical research studies involving devices and new therapeutic strategies.
Evolutionary full-waveform inversion
Authors: van Herwaarden Dirk Philip , Afanasiev Michael , Thrastarson Solvi , Fichtner Andreas
Published: September 2020

We present a new approach to full-waveform inversion (FWI) that enables the assimilation of data sets that expand over time without the need to reinvert all data. This evolutionary inversion rests on a reinterpretation of stochastic Limited-memory Broyden–Fletcher–Goldfarb–Shanno (L-BFGS), which randomly exploits redundancies to achieve convergence without ever considering the data set as a whole. Specifically for seismological applications, we consider a dynamic mini-batch stochastic L-BFGS, where the size of mini-batches adapts to the number of sources needed to approximate the complete gradient. As an illustration we present an evolutionary FWI for upper-mantle structure beneath Africa. Starting from a 1-D model and data recorded until 1995, we sequentially add contemporary data into an ongoing inversion, showing how (i) new events can be added without compromising convergence, (ii) a consistent measure of misfit can be maintained and (iii) the model evolves over times as a function of data coverage. Though applied retrospectively in this example, our method constitutes a possible approach to the continuous assimilation of seismic data volumes that often tend to grow exponentially.
Cavitary lung lesions and pneumothorax in a healthy patient with active coronavirus-19 (COVID-19) viral pneumonia
Authors: Afrazi Amin , Garcia-Rodriguez Sylvana , Maloney James D , Morgan Clinton T
Published: September 2020

Severe respiratory sequelae drive morbidity-associated with coronavirus 2019 (COVID-19) disease. We report a case of COVID-19 pneumonia complicated by cavitary lesions and pneumothorax in a young healthy male. Pneumothorax management with catheter thoracostomy and rapid resolution of the cavitary lesions are described. An extensive work-up for other causes a cavitation was negative and the temporal correlation of the cavities with COVID-19 infection plus their rapid resolution suggest a direct relationship. We propose a mechanism for cavitation secondary to microangiopathy, a cause of cavitation in the vasculitides and a known feature of COVID-19.
Can soluble urokinase plasminogen receptor predict outcomes after cardiac surgery?
Authors: Schultz-Swarthfigure Chase T , McCall Philip , Docking Robert , Galley Helen F , Shelley Benjamin
Published: September 2020

OBJECTIVES

Soluble urokinase plasminogen activator receptor (suPAR) is a biomarker that has been implicated in several cardiac pathologies and has been shown to be elevated in critically ill populations. We measured plasma suPAR in a cohort of cardiac surgical patients to evaluate its ability to predict prolonged intensive care unit (ICU) and hospital length of stay and development of complications following surgery. We compared suPAR against EuroSCORE II and C-reactive protein (CRP).

METHODS

Ninety patients undergoing cardiac surgery were recruited with samples taken preoperatively and on postoperative days 1, 2 and 3. suPAR was measured using enzyme-linked immunosorbent assay. Area under the receiver operator curve (AUROC) was used to test predictive capability of suPAR. Comparison was made with EuroSCORE II and CRP.

RESULTS

suPAR increased over time (P < 0.001) with higher levels in patients requiring prolonged ICU and hospital stay, and prolonged ventilation (P < 0.05). suPAR was predictive for prolonged ICU and hospital stay, and prolonged ventilation at all time points (AUROC 0.66–0.74). Interestingly, this association was also observed preoperatively, with preoperative suPAR predicting prolonged ICU (AUROC 0.66), and hospital stay (AUROC 0.67) and prolonged ventilation (AUROC 0.74). The predictive value of preoperative suPAR compared favourably to EuroSCORE II and CRP.

CONCLUSIONS

suPAR increases following cardiac surgery and levels are higher in those who require prolonged ICU stay, prolonged hospital stay and prolonged ventilation. Preoperative suPAR compares favourably to EuroSCORE II and CRP in the prediction of these outcomes. suPAR could be a useful biomarker in predicting outcome following cardiac surgery, helping inform clinical decision-making.

Clinical registration

West of Scotland Research Ethics Committee Reference: 12/WS/0179 (AM01).
Evidence for familial clustering in breast cancer age of onset
Authors: Von Holle Ann , O’Brien Katie M , Sandler Dale P , Weinberg Clarice R
Published: September 2020

Background

Familial clustering of age at onset would have implications for both personalized screening and aetiology, but has not been studied for breast cancer.

Methods

We prospectively studied a cohort of 23 145 sisters to explore whether their breast cancer risk changed near the age at diagnosis of a previously affected older sister. Using an age-time-dependent variable in a Cox regression model, we estimated hazard ratios for breast cancer when participants were near their sister’s diagnosis age, relative to similarly aged women whose sister was diagnosed at a very different age. To rule out a correlation driven by young-onset familial cancer, we separately investigated women who had enrolled at age 50 or older.

Results

Of the 23 145 women, 1412 developed breast cancer during follow-up (median 9.5 years). The estimated hazard ratio was 1.80 (95% confidence interval: 1.18, 2.74) at their sister’s age at diagnosis, suggesting a substantial increase in risk compared with women of the same age but whose sister was diagnosed at a very different age. Restriction to women who enrolled at or after age 50 produced similar results.

Conclusions

This familial clustering suggests that there may be important genetic and/or early environmental risk factors that influence the timing of breast cancer, even when onset is late in life. Personalized screening might need to account for the age at which a sister was earlier diagnosed with breast cancer.
A mathematical model of asynchronous data flow in parallel computers*
Authors: Barnard Richard C , Huang Kai , Hauck Cory
Published: September 2020

We present a simplified model of data flow on processors in a high-performance computing framework involving computations necessitating inter-processor communications. From this ordinary differential model, we take its asymptotic limit, resulting in a model which treats the computer as a continuum of processors and data flow as an Eulerian fluid governed by a conservation law. We derive a Hamilton–Jacobi equation associated with this conservation law for which the existence and uniqueness of solutions can be proven. We then present the results of numerical experiments for both discrete and continuum models; these show a qualitative agreement between the two and the effect of variations in the computing environment’s processing capabilities on the progress of the modelled computation.
Bridging theOtherSide of the Gap: Teaching “Practical Theory” to Future Practitioners
Authors: Blankshain Jessica D , Cooper David A , Gvosdev Nikolas K
Published: September 2020

Much has been written about the need to “bridge the gap” between the academic study of international relations—particularly policy-oriented subfields such as foreign policy analysis and security studies—and the needs of policymakers. This important agenda largely focuses on encouraging academics to produce more policy-relevant, accessible research. While such efforts are indispensable, they neglect another important piece of the equation: teaching future policymakers how to translate theory into practice. The bridge needs to be a two-way street. Scholars add value for policy because their work is grounded in theory, offering analytical structure to make sense of a complex world. But applying theory to policy is unlikely to resonate with practitioners who do not have the basic conceptual literacy to grasp why theory-informed research is relevant to their own hands-on concerns. We therefore propose a teaching approach we term “practical theory,” geared specifically for professionally oriented students. Drawing on our own experience in teaching, developing curriculum, and writing for students in professional master's degree programs, we recommend instructors: choose theories and frameworks that are most likely to be useful in practice, update these theories for the times as needed, reconsider nomenclature and banish unnecessary academic jargon, and apply theory early and often.
The changing epidemiology of carbapenemase-producingKlebsiella pneumoniaein Italy: toward polyclonal evolution with emergence of high-risk lineages
Authors: Di Pilato Vincenzo , Errico Giulia , Monaco Monica , Giani Tommaso , Del Grosso Maria , Antonelli Alberto , David Sophia , Lindh Erika , Camilli Romina , Aanensen David M , Rossolini Gian Maria , Pantosti Annalisa ,   the AR-ISS Laboratory Study Group on carbapenemase-producing Klebsiella pneumoniae, Manso E , Pedna M F , Mungiguerra M , Moscati Presidio Ospedaliero G , Mosca A , Vailati F , Aschbacher R , Imbriani A , Sartore P , di Cittadella Ospedale Civile , Giraldi C , di Cosenza Azienda Ospedaliera , Piana F , Pecile P , Careggi Ospedale , De Nittis R , Pini B , Manzoni Ospedale A , Mirri P , Bianchi E , Restelli A , Morelli D , Tumori Istituto , Catania M R , Barbaro A , Bernaschi P , Parisi G , Gualdi P , Dusi P A , Bona R , Paolo Ospedale S , D’Andrea M M , Cavallo R , Lanzafame P , Sartor A , Grandesso S , Milano F
Published: September 2020

Background

Previous studies showed that the epidemic of carbapenem-resistant Klebsiella pneumoniae (CR-KP) observed in Italy since 2010 was sustained mostly by strains of clonal group (CG) 258 producing KPC-type carbapenemases. In the framework of the National Antibiotic-Resistance Surveillance (AR-ISS), a countrywide survey was conducted in 2016 to explore the evolution of the phenotypic and genotypic characteristics of CR-KP isolates.

Methods

From March to July 2016, hospital laboratories participating in AR-ISS were requested to provide consecutive, non-duplicated CR-KP (meropenem and/or imipenem MIC >1 mg/L) from invasive infections. Antibiotic susceptibility was determined according to EUCAST recommendations. A WGS approach was adopted to characterize the isolates by investigating phylogeny, resistome and virulome.

Results

Twenty-four laboratories provided 157 CR-KP isolates, of which 156 were confirmed as K. pneumoniae sensu stricto by WGS and found to carry at least one carbapenemase-encoding gene, corresponding in most cases (96.1%) to blaKPC. MLST- and SNP-based phylogeny revealed that 87.8% of the isolates clustered in four major lineages: CG258 (47.4%), with ST512 as the most common clone, CG307 (19.9%), ST101 (15.4%) and ST395 (5.1%). A close association was identified between lineages and antibiotic resistance phenotypes and genotypes, virulence traits and capsular types. Colistin resistance, mainly associated with mgrB mutations, was common in all major lineages except ST395.

Conclusions

This WGS-based survey showed that, although CG258 remained the most common CR-KP lineage in Italy, a polyclonal population has emerged with the spread of the new high-risk lineages CG307, ST101 and ST395, while KPC remained the most common carbapenemase.
Different processes for translating expressive versus informative texts? A computer-assisted study of professionals’ English–Chinese translation
Authors: Zheng Jianwei , Fan Wenjun
Published: September 2020

This article explores the differences of translation processes for expressive and informative texts by professional translators primarily by triangulating pausing and revision data retrieved by Keystroke logging experiment and rational report thereof via questionnaire survey and interview. The article discovers that in terms of temporal distribution, the drafting of informative text accounts for a larger proportion of time, while orientation and checking accounts for a smaller proportion compared with those of expressive texts. At orientation interval, translators come to fully understand the source expressive text at the very beginning, while generally conducting syntactic analysis of and re-sequencing the semantic component of source text in target language in translating informative text. At drafting interval, structural modification frequency word rate (MWR) in translating the expressive text is larger than that in translating the informative texts, while spelling and lexical MWRs of both texts are similar. At checking interval, both texts hardly see any structural modification, but lexical MWR for the former is much bigger than that for the latter. These data, along with pausing and revision rational report, suggest the priority of familiarity with standardized grammar and expertise in specialized field for translating informative text, and the importance of embedded reading and writing training for translating expressive text.
From solar-like to mira stars: a unifying description of stellar pulsators in the presence of stochastic noise
Authors: Cunha M S , Avelino P P , Chaplin W J
Published: September 2020

We discuss and characterize the power spectral density properties of a model aimed at describing pulsations in stars from the main-sequence to the asymptotic giant branch. We show that the predicted limit of the power spectral density for a pulsation mode in the presence of stochastic noise is always well approximated by a Lorentzian function. While in stars predominantly stochastically driven the width of the Lorentzian is defined by the mode lifetime, in stars where the driving is predominately coherent the width is defined by the amplitude of the stochastic perturbations. In stars where both drivings are comparable, the width is defined by both these parameters and is smaller than that expected from pure stochastic driving. We illustrate our model through numerical simulations and propose a well-defined classification of stars into predominantly stochastic (solar-like) and predominately coherent (classic) pulsators. We apply the model to the study of the Mira variable U Per, and the semiregular variable L2 Pup and, following our classification, conclude that they are both classical pulsators. Our model provides a natural explanation for the change in behaviour of the pulsation amplitude-period relation noted in several earlier works. Moreover, our study of L2 Pup enables us to test the scaling relation between the mode line width and effective temperature, confirming that an exponential scaling reproduces well the data all the way from the main sequence to the asymptotic giant branch, down to temperatures about 1000 K below what has been tested in previous studies.
H i scale height in spiral galaxies
Authors: Patra Narendra Nath
Published: September 2020

We model the galactic discs of seven nearby large spiral galaxies as three-component systems consist of stars, molecular gas, and atomic gas in vertical hydrostatic equilibrium. We set up the corresponding joint Poisson–Boltzmann equation and solve it numerically to estimate the 3D distribution of H i in these galaxies. While solving the Poisson–Boltzmann equation, we do not consider a constant H i velocity dispersion (σHI); rather, we develop an iterative method to self-consistently estimate the σHI profile in a galaxy by using the observed second-moment profile of the H i spectral cube. Using the density solutions, we determine the H i vertical scale height in our galaxies. We find that the H i discs flare in a linear fashion as a function of radius. H i scale height in our galaxies is found to vary between a few hundred parsecs at the centre to ∼1–2 kpc at the outskirts. We estimate the axial ratio of the H i discs in our sample galaxies and find a median ratio of 0.1, which is much lower than what is found for dwarf galaxies, indicating much thinner H i discs in spiral galaxies. Very low axial ratios in three of our sample galaxies (NGC 5055, NGC 6946, and NGC 7331) suggest them to be potential superthin galaxies. Using the H i distribution and the H i hole sizes in NGC 6946, we find that most of the H i holes in this galaxy are broken out into the circumgalactic medium and this breaking out is more effective in the inner radii as compared to the outer radii.
Wide-field study of the peculiar globular cluster system hosted by the field lenticular NGC 1172
Authors: Ennis Ana Inés , Caso Juan Pablo , Bassino Lilia P , Salinas Ricardo , Gómez Matías
Published: September 2020

We present a wide-field study of the globular cluster system (GCS) of the field lenticular galaxy NGC 1172, based on observations from Gemini Multi-Object Spectrograph/Gemini (optical), FourStar/Magellan (NIR), and archival data from ACS/Hubble Space Telescope (optical). This analysis covers the full extension of the GCS, and results in a value of specific frequency (SN = 8.6 ± 1.5) peculiarly high for an intermediate-mass galaxy in a low-density environment such as this one. We find that the GCS appears to be bimodal, although the colour distribution is narrow and does not allow for an accurate separation of the subpopulations. However, the combination of optical and NIR filters allows us to obtain an estimation of the metallicity distribution based on the photometry, which supports bimodality. We conclude that the presence of a large fraction of metal-poor globular clusters (GCs) and the high specific frequency point to NGC 1172 having accreted a significant amount of GCs from low-mass satellites in the past.
Tensorial solution of the Poisson equation and the dark matter amount and distribution of UGC 8490 and UGC 9753
Authors: Repetto P
Published: September 2020

In the first part of this article we expand three fundamental aspects of the methodology connected to the determination of a relation among the spatial density and the gravitational potential that can be specialized to distinct mass density agglomerations. As a consequence, we obtain general relations for the diagonal entries of a square symmetric matrix without zeros, we provide an expression of the gravitational potential, suitable, to represent several different mass density configurations, and we determine relations for the semi-axes of a triaxial spheroidal mass distribution, as a function of the spheroid mass density, volume density, and radius. In the second part of this paper, we employ the tools developed in the first part, to analyse the mass density content and the inner and global structure of the dark matter haloes of UGC 8490 and UGC 9753, through the fits to the dark matter rotation curves of the two galaxies, assuming a triaxial spheroidal dark matter mass configuration. We employ the Navarro Frenk and White, Burkert, DiCintio, Einasto and Stadel dark matter models, and we obtain that both a cored Burkert and cuspy DiCintio and Navarro Frenk and White inward dark matter distributions could represent equally well the observed data, furthermore we determine an oblate spheroidal dark matter mass density configuration for UGC 8490 and UGC 9753. The latter outcome is confirmed by the estimation of the gravitational torques exerted by the dark matter halo of each analysed galaxy, on the corresponding baryonic components.