bluuebunny/crossref_metadata_2025 huggingface dataset:
Coherent optical communications enhanced by machine intelligence
Authors: Lohani Sanjaya , Glasser Ryan T
Published: June 2020

Accuracy in discriminating between different received coherent signals is integral to the operation of many free-space communications protocols, and is often difficult when the receiver measures a weak signal. Here we design an optical communication scheme that uses balanced homodyne detection in combination with an unsupervised generative machine learning and convolutional neural network (CNN) system, and demonstrate its efficacy in a realistic simulated coherent quadrature phase shift keyed (QPSK) communications system. Additionally, we design the neural network system such that it autonomously learns to correct for the noise associated with a weak QPSK signal, which is distributed to the receiver prior to the implementation of the communications. We find that the scheme significantly reduces the overall error probability of the communications system, achieving the classical optimal limit. We anticipate that these results will allow for a significant enhancement of current classical and quantum coherent optical communications technologies.
Moduli of formal torsors
Authors: Tonini Fabio , Yasuda Takehiko
Published: June 2020

We construct the moduli stack of torsors over the formal punctured disk in characteristic

p
>
0

p>0

for a finite group isomorphic to the semidirect product of a

p
p

-group and a tame cyclic group. We prove that the stack is a limit of separated Deligne-Mumford stacks with finite and universally injective transition maps.
FoldRec-C2C: protein fold recognition by combining cluster-to-cluster model and protein similarity network
Authors: Shao Jiangyi , Yan Ke , Liu Bin
Published: June 2020

As a key for studying the protein structures, protein fold recognition is playing an important role in predicting the protein structures associated with COVID-19 and other important structures. However, the existing computational predictors only focus on the protein pairwise similarity or the similarity between two groups of proteins from 2-folds. However, the homology relationship among proteins is in a hierarchical structure. The global protein similarity network will contribute to the performance improvement. In this study, we proposed a predictor called FoldRec-C2C to globally incorporate the interactions among proteins into the prediction. For the FoldRec-C2C predictor, protein fold recognition problem is treated as an information retrieval task in nature language processing. The initial ranking results were generated by a surprised ranking algorithm Learning to Rank, and then three re-ranking algorithms were performed on the ranking lists to adjust the results globally based on the protein similarity network, including seq-to-seq model, seq-to-cluster model and cluster-to-cluster model (C2C). When tested on a widely used and rigorous benchmark dataset LINDAHL dataset, FoldRec-C2C outperforms other 34 state-of-the-art methods in this field. The source code and data of FoldRec-C2C can be downloaded from http://bliulab.net/FoldRec-C2C/download.
Unexpected low genetic differentiation between Japan and Bering Sea populations of a deep-sea benthic crustacean lacking a planktonic larval stage (Peracarida: Tanaidacea)
Authors: Kakui Keiichi , Nomaki Hidetaka , Komatsu Hironori , Fujiwara Yoshihiro
Published: June 2020

Information on the extent, diversity and connectivity of populations is lacking for most deep-sea invertebrates. Species of the order Tanaidacea (Crustacea), one of the most diverse and abundant macrofaunal groups in the deep sea, are benthic, lack a planktonic larval stage, and thus would be expected to have narrow distributional ranges. However, with molecular evidence from the COI gene, we show here that the deep-sea tanaidacean Carpoapseudes spinigena has a distributional range spanning at least 3700 km, from off northern Japan to the south-eastern Bering Sea. Living individuals found in a sediment core indicated that the species is a sedentary burrower. COI analyses revealed a low level of genetic diversity overall, and low differentiation (p-distance, 0.2–0.8%) between the Japan and Bering Sea populations. One hypothesis to explain the low genetic diversity over a broad region is that the Japan population was founded by individuals transported by ocean currents from the Bering Sea. However, due to limited data, other explanations cannot be ruled out. Our results indicate that continued sampling is of fundamental importance to understanding how genetic and taxonomic diversity originate and are maintained in the deep sea.
Rapid Detection Methods for Bacterial Pathogens in Ambient Waters at the Point of Sample Collection: A Brief Review
Authors: Li Jing , Zhu Yanzhe , Wu Xunyi , Hoffmann Michael R
Published: June 2020

The world is currently facing a serious health burden of waterborne diseases, including diarrhea, gastrointestinal diseases, and systemic illnesses. The control of these infectious diseases ultimately depends on the access to safe drinking water, properly managed sanitation, and hygiene practices. Therefore, ultrasensitive, rapid, and specific monitoring platforms for bacterial pathogens in ambient waters at the point of sample collection are urgently needed. We conducted a literature review on state-of-the-art research of rapid in-field aquatic bacteria detection methods, including cell-based methods, nucleic acid amplification detection methods, and biosensors. The detection performance, the advantages, and the disadvantages of the technologies are critically discussed. We envision that promising monitoring approaches should be automated, real-time, and target-multiplexed, thus allowing comprehensive evaluation of exposure risks attributable to waterborne pathogens and even emerging microbial contaminants such as antibiotic resistance genes, which leads to better protection of public health.
Performance of Oropharyngeal Swab Testing Compared With Nasopharyngeal Swab Testing for Diagnosis of Coronavirus Disease 2019—United States, January 2020–February 2020
Authors: Patel Monita R , Carroll Darin , Ussery Emily , Whitham Hilary , Elkins Christopher A , Noble-Wang Judith , Rasheed James Kamile , Lu Xiaoyan , Lindstrom Stephen , Bowen Virginia , Waller Jessica , Armstrong Gregory , Gerber Susan , Brooks John T
Published: June 2020

Among 146 nasopharyngeal (NP) and oropharyngeal (OP) swab pairs collected ≤7 days after illness onset, Real-Time Reverse Transcriptase Polymerase Chain Reaction assay for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 RT-PCR) diagnostic results were 95.2% concordant. However, NP swab cycle threshold values were lower (indicating more virus) in 66.7% of concordant-positive pairs, suggesting NP swabs may more accurately detect the amount of SARS-CoV-2.
Asymptomatic SARS-CoV-2 Infection and COVID-19 Mortality During an Outbreak Investigation in a Skilled Nursing Facility
Authors: Patel Mahesh C , Chaisson Lelia H , Borgetti Scott , Burdsall Deborah , Chugh Rashmi K , Hoff Christopher R , Murphy Elizabeth B , Murskyj Emily A , Wilson Shannon , Ramos Joe , Akker Lynn , Bryars Debra , Thomas-Smith Evonda , Bleasdale Susan C , Ezike Ngozi O
Published: June 2020

Background

Outbreaks of coronavirus disease 2019 (COVID-19) have been reported in nursing homes and assisted living facilities; however, the extent of asymptomatic and presymptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in this high-risk population remains unclear.

Methods

We conducted an investigation of the first known outbreak of SARS-CoV-2 at a skilled nursing facility (SNF) in Illinois on 15 March 2020 and followed residents for 30 days. We tested 126/127 residents for SARS-CoV-2 via reverse-transcription polymerase chain reaction and performed symptom assessments. We calculated the point prevalence of SARS-CoV-2 and assessed symptom onset over 30-day follow-up to determine: (1) the proportion of cases who were symptomatic, presymptomatic, and asymptomatic and (2) incidence of symptoms among those who tested negative. We used the Kaplan-Meier method to determine the 30-day probability of death for cases.

Results

Of 126 residents tested, 33 had confirmed SARS-CoV-2 on 15 March. Nineteen (58%) had symptoms at the time of testing, 1 (3%) developed symptoms over follow-up, and 13 (39%) remained asymptomatic. Thirty-five residents who tested negative on 15 March developed symptoms over follow-up; of these, 3 were re-tested and 2 were positive. The 30-day probability of death among cases was 29%.

Conclusions

SNFs are particularly vulnerable to SARS-CoV-2, and residents are at risk of severe outcomes. Attention must be paid to preventing outbreaks in these and other congregate care settings. Widespread testing and infection control are key to help prevent COVID-19 morbidity and mortality in these high-risk populations.
Alterations of the Oral Microbiome and Cumulative Carbapenem Exposure Are Associated With Stenotrophomonas maltophilia Infection in Patients With Acute Myeloid Leukemia Receiving Chemotherapy
Authors: Aitken Samuel L , Sahasrabhojane Pranoti V , Kontoyiannis Dimitrios P , Savidge Tor C , Arias Cesar A , Ajami Nadim J , Shelburne Samuel A , Galloway-Peña Jessica R
Published: June 2020

Background

Stenotrophomonas maltophilia is increasingly common in patients with acute myeloid leukemia (AML). Little is known about factors that drive S. maltophilia infection. We evaluated the microbiome and cumulative antibiotic use as predictors of S. maltophilia infection in AML patients receiving remission induction chemotherapy (RIC).

Methods

Subanalysis of a prospective, observational cohort of patients with AML receiving RIC between September 2013 and August 2015 was performed. Fecal and oral microbiome samples collected from initiation of RIC until neutrophil recovery were assessed for the relative abundance of Stenotrophomonas via 16S rRNA gene quantitation. The primary outcome, microbiologically proven S. maltophilia infection, was analyzed using a time-varying Cox proportional hazards model.

Results

Of 90 included patients, 8 (9%) developed S. maltophilia infection (pneumonia, n = 6; skin–soft tissue, n = 2); 4/8 (50%) patients were bacteremic; and 7/8 (88%) patients with S. maltophilia infection had detectable levels of Stenotrophomonas vs 22/82 (27%) without infection (P < .01). An oral Stenotrophomonas relative abundance of 36% predicted infection (sensitivity, 96%; specificity, 93%). No association of S. maltophilia infection with fecal relative abundance was found. Cumulative meropenem exposure was associated with increased infection risk (hazard ratio, 1.17; 95% confidence interval, 1.01–1.35; P = .03).

Conclusions

Here, we identify the oral microbiome as a potential source for S. maltophilia infection and highlight cumulative carbapenem use as a risk factor for S. maltophilia in leukemia patients. These data suggest that real-time monitoring of the oral cavity might identify patients at risk for S. maltophilia infection.
The Role of FER rs4957796 in the Risk of Developing and Dying from a Bloodstream Infection: A 23-Year Follow-up of the Population-based Nord-Trøndelag Health Study
Authors: Rogne Tormod , Damås Jan Kristian , Flatby Helene Marie , Åsvold Bjørn Olav , DeWan Andrew Thomas , Solligård Erik
Published: June 2020

Background

Bloodstream infection and sepsis are major causes of health loss worldwide, and it is important to identify patients at risk of developing and dying from these conditions. The single-nucleotide polymorphism most strongly associated with sepsis mortality is FER rs4957796. However, it is not known how this variant is associated with bloodstream infection incidence and mortality.

Methods

We used prospective data from 1995–2017 from the population-based HUNT Study. Genotypes were ascertained from blood samples, and additional genotypes were imputed. Information on bloodstream infection and diagnosis codes at hospitalization were collected through record linkage with all hospitals in the area.

Results

A total of 69 294 patients were included. Patients with the rs4957796 CC genotype had an increased risk of developing a bloodstream infection compared with the TT genotype (hazard ratio [HR], 1.20; 95% confidence interval [CI], 1.00–1.43). However, there was a protective additive effect of the C allele in terms of mortality in the total study population (HR, 0.77; 95% CI, .64–.92 per copy of the C allele) and among bloodstream infection patients (odds ratio, 0.70; 95% CI, .58–.85 per copy of the C allele). The results did not appear to be affected by selection bias.

Conclusions

The rs4957796 CC genotype was associated with an increased risk of contracting a bloodstream infection but with a reduced risk of dying from one. The latter finding is in line with studies of sepsis case fatality, while the former expands our understanding of the immunoregulatory role of this polymorphism.
Managerial myopia and short-termism of innovation strategy: Financialisation of Korean firms
Authors: Seo Hwan Joo , Kang Sung Jin , Baek Yong Jun
Published: June 2020

This study empirically examines whether managerial myopia leads to short-termism of innovation strategy using Korean firm and USPTO data covering 1980–2017. The main finding is that payout indicators, as the proxy variables for financialisation and managerial myopia, have a negative effect on innovation, quantitatively and qualitatively. Hence, managerial myopia and short-termism of innovation strategy are related. Further, estimation by the firm’s size reveals that the hypothesis of managerial myopia leading to short-termism of innovation strategy is valid only for conglomerates.
Capital in the history of economic thought: charting the ontological underworld
Authors: Endres Anthony M , Harper David A
Published: June 2020

We undertake a comprehensive descriptive and comparative ontology of capital in the history of economic thought post-1870. Beginning with the pioneering contributions of Menger, Böhm-Bawerk, Clark and Knight, we reassess the familiar dualistic ontology of capital that contrasts ‘materialist’ and ‘fundist’ approaches. Advancing beyond this dualism, we find that the ontology of capital is an evolving mosaic presenting many nuances and overlapping with other ontologies concerning notions of time and atomism. There is no substitute for examining the diverse theories, causal explanations and conceptual systems in which capital is embedded. In episodic capital controversies, economists have employed distinctive metaphors of capital revealing hidden presuppositions that imply specific functional and dispositional properties of capital. Ontological comparison can uncover implicit ideas about capital, as evidenced in the metaphors used by Böhm-Bawerk, Hayek and Robinson. The benefits of a descriptive and comparative approach are further illustrated in our critical appraisal of the modern monetary ontology of capital associated with Piketty, business finance and growth accounting. Differentiated by their specific ontologies, each explanation of capital in market economies should be regarded as at best a very partial account, though our assessment shows that some explanations are relatively more fragmentary and impoverished than others.
Inflammatory Bowel Disease in the COVID-19 Pandemic: the Patients’ Perspective
Authors: Grunert P C , Reuken P A , Stallhofer J , Teich N , Stallmach A
Published: June 2020

Background

The coronavirus disease 2019 [COVID-19] pandemic is affecting lives worldwide. The influence of inflammatory bowel disease [IBD] medication and IBD itself on COVID-19 is controversial. Additionally, IBD-focused guidance is scarce.

Objective

Our aims were to determine COVID-19 prevalence/exposure, perception and information sources, medication compliance, patient behaviour and physician contact among patients with IBD compared with non-IBD controls.

Methods

A cross-sectional anonymous survey of patients with IBD [N = 415] at one university IBD clinic and one gastroenterology practice, matched 4:1 with control participants [N = 116], was performed.

Results

Patients with IBD had a high fear of infection. This was more pronounced in patients taking immunosuppressants and it extended to hospitals, private practices and public places, such as supermarkets. IBD patients reported leaving their homes less frequently than their peers without IBD. A total of 90% of patients with IBD reported washing their hands more frequently. Patients taking immunosuppressants were concerned about interactions between medication and COVID-19, whereas patients taking 5-aminosalicylates were not. Nonetheless, 96.4% of patients adhered to continuing their medication. Patients sought guidance primarily from television and internet news sites. Video consultations were found to be a suitable solution for a subset of patients who are young, have a high level of fear and leave their home less frequently than their peers, whereas overall acceptance of video consultations was limited.

Conclusion

Patients with IBD are significantly more affected by the COVID-19 pandemic than their non-IBD peers, but they continue to adhere to their medication regimens. IBD-focused COVID-19 information should be actively conveyed.
Left ventricular thrombosis: new perspectives on an old problem
Authors: Massussi Mauro , Scotti Andrea , Lip Gregory Y H , Proietti Riccardo
Published: June 2020

Left ventricular thrombosis (LVT) is a major risk factor for systemic thromboembolism and might complicate both the acute and the chronic phase of ischaemic heart disease after myocardial infarction and, less frequently, non-ischaemic cardiomyopathies. The pathophysiology of thrombus formation is complex and involves the three aspects of Virchow’s triad: blood stasis, prothrombotic state, and tissue injury. Advances in technology have improved the detection rate of intracardiac thrombi, but several uncertainties still remain regarding the optimal treatment strategy within daily clinical practice. Of note, anticoagulation therapy with heparin and vitamin K antagonists decreases the risk of embolic stroke though exposing patients to an undeniable risk of bleeding complications. Although limited data on the off-label use of direct oral anticoagulants have reported safety and efficacy for LVT resolution, yet more evidence is needed to justify their use in clinical practice.
Characterization of porous rocks embedded with aligned fractures from shear wave responses
Authors: Wang Ding , Li Bo
Published: June 2020

A single shear wave passing through an elastic anisotropic rock can split into two quasi-shear waves (noted by S1 and S2) with different polarization forms if the particle vibration direction of the wave source does not lie in the symmetry plane of the rock. This study focuses on the properties of shear waves penetrating a porous rock containing a set of aligned permeable fractures. The polarization characteristics of shear waves were selected to describe the dynamic properties of the rock as they are sensitive to the parameters of fractures and saturating fluids. From a physics viewpoint, in addition to the compressional wave, the shear wave (splitting) is governed by a wave-induced fluid flow (WIFF) process due to the specific shear stress decomposition happening on the fractures. The polarization formulas of S1 and S2 were derived based on the frequency-dependent Christoffel equation, which are related to the properties of fractures, fluids and wave frequency. The influence of the properties of fractures and fluids on the velocity and attenuation anisotropies of shear waves were analysed. The results showed that the particle oscillations of two shear waves are not completely mutually orthogonal, and are affected by the pressure equilibrium magnitude between the fractures and the corresponding interconnected pores. The S2 (slow) wave (i.e. particle polarized on the plane approximately perpendicular to the fractures) is more sensitive to the saturated fluids and the WIFF process than that of the S1 (fast) wave (i.e. wave polarized on the plane approximately parallel to the fractures). A frequency factor was proposed for quantifying the effects of WIFF on shear wave polarization and attenuation. Measurements on the unique polarization and the anisotropy of shear waves can provide a generalized indicator to predict the properties of fractures and the migration of infilling fluids in the rock fracture systems.
Refractory Inflammatory Bowel Disease Associated With Sclerosing Cholangitis, Diabetes Insipidus, and Myeloid Neoplasm: Langerhans Cell Histiocytosis Was Hiding Since the Beginning
Authors: Razanamahery Jerome , Humbert Sebastien , Weil-Verhoeven Delphine , Emile Jean-Francois , Vuitton Lucine , Magy-Bertrand Nadine
Published: June 2020

Langerhans cell histiocytosis is a rare histiocytic disorder characterized by histology (CD68+, CD1a+ histiocytes). Presentation is heterogenous but gastrointestinal tract involvement is rare; although it can mimic inflammatory bowel disease, such an association is unusual.
A 1-Year Cross-sectional Inflammatory Bowel Disease Surveillance Colonoscopy Cohort Comparing High-definition White Light Endoscopy and Chromoendoscopy
Authors: Coelho-Prabhu Nayantara , Bruining David H , Faubion William A , Kane Sunanda V , Kisiel John B , Papadakis Konstantinos A , Pardi Darrell S , Raffals Laura E , Schroeder Kenneth W , Tremaine William J , Fruth Kristin , Harmsen W Scott , Loftus Edward V
Published: June 2020

Background

We sought to compare the dysplasia detection rate of high-definition white light endoscopy (HDWLE) with that of chromoendoscopy in patients with long-standing inflammatory bowel disease (IBD).

Methods

This is a retrospective observational cohort of patients with IBD who underwent surveillance colonoscopy between October 1, 2016 and September 30, 2017. We assessed the association between dysplasia detection and multiple variables.

Results

A total of 808 unique colonoscopies were performed, of which 150 (18.6%) included chromoendoscopy. Primary sclerosing cholangitis was a comorbid diagnosis in 24.5% of patients. The performing endoscopist was an IBD specialist with 37.1% of patients and had >10 years’ experience with 64.9% of patients. Prior dysplasia had been seen in 245 (30.3%) patients: 102 (68.0%) and 143 (22.0%) among patients who had chromoendoscopy and HDWLE, respectively. Dysplasia in polyps was found in 129 procedures (15.1%). Among patients who had chromoendoscopy and HDWLE, polypoid dysplasia was identified in 50 (33.0%) and 79 (12.0%) patients, respectively, P < 0.01. Dysplasia in random biopsies was found in 39 patients (4.8%): 15 (10%) who had chromoendoscopy and 24 (3.6%) who had HDWLE (P < 0.001). On multivariate analysis, patient and disease characteristics significantly associated with an increased odds for polypoid dysplasia included older age at diagnosis (odds ratio [OR] = 1.3 per 10 years; 95% confidence interval [CI], 1.07-1.60), having an IBD physician endoscopist (OR = 1.6; 95% CI, 1.01-2.67), having an endoscopist with less than 10 years’ experience (OR = 1.8; 95% CI (1.16-2.89), and prior random dysplasia (OR = 4.2; 95% CI (1.93-9.17). Concomitant primary sclerosing cholangitis was significantly associated with random dysplasia (OR = 2.3; 95% CI, 1.02-5.07). After multivariate analysis adjusting for these variables, chromoendoscopy was no more likely to identify dysplasia than was HDWLE.

Conclusions

Chromoendoscopy and HDWLE had a similar diagnostic yield for dysplasia detection in patients with chronic IBD-colitis after adjusting for multiple known risk factors.
Investigating the potential for a commercial fishery in the Northeast Atlantic utilizing mesopelagic species
Authors: Grimaldo Eduardo , Grimsmo Leif , Alvarez Paula , Herrmann Bent , Møen Tveit Guro , Tiller Rachel , Slizyte Rasa , Aldanondo Naroa , Guldberg Trude , Toldnes Bendik , Carvajal Ana , Schei Marte , Selnes Merethe
Published: June 2020

During three cruises in the Mid Atlantic Ridge area in 2016 and 2017, we studied the biomass of mesopelagic fish and its potential as a source of protein and oil for animal feed and human consumption. We collected samples of mesopelagic species down to a depth of 600 m, studied fish behaviour, identified and quantified the species composition of the catches, analysed the chemical composition of the catch samples, and evaluated the presence of unwanted substances. Results showed that Maurolicus muelleri (Mueller’s pearlside) and Benthosema glaciale (Glacier lantern fish) were the most abundant fish species in our samples and catches containing 80% fish can be a good source of protein and marine lipids including eicosapentaenoic acid (C20:5n3) and docosahexaenoic acid (C22:6n3). Unwanted substances, except for Cd and As, were present at levels far lower than the limits set by European Union regulations. However, our experiments identified challenges that may limit the efficiency of commercial operations in the Northeast Atlantic. Combined real-time optical and/or multifrequency acoustic systems will be needed to improve species identification and ensure cost-effective fishing operations. Also, selective trawls that target only fish and release unwanted species are needed to secure high-quality oils and proteins.
Will Coronavirus Disease 2019 Become Seasonal?
Authors: Kanzawa Mia , Spindler Hilary , Anglemyer Andrew , Rutherford George W
Published: June 2020

This manuscript explores the question of the seasonality of severe acute respiratory syndrome coronavirus 2 by reviewing 4 lines of evidence related to viral viability, transmission, ecological patterns, and observed epidemiology of coronavirus disease 2019 in the Southern Hemispheres’ summer and early fall.
Macroeconomic Fluctuations with HANK & SAM: an Analytical Approach
Authors: Ravn Morten O , Sterk Vincent
Published: June 2020

Recently developed HANK models, which combine Heterogeneous Agents and New Keynesian frictions, have had a considerable impact on macroeconomics. However, due to the complexity of such models, the literature has focused on numerically solved models and therefore little is known about their general properties. This paper presents a tractable HANK model that integrates Search and Matching (SAM) frictions in the labor market. The model features an endogenous idiosyncratic earnings risk, which may be procyclical or countercyclical. When this risk is countercyclical, which we argue is the empirically plausible case, there is a downward pressure on real interest rates in recessions due to a precautionary savings motive. We show that in this setting (a) the economy may get stuck in a high-unemployment steady state, (b) the Taylor principle is insufficient to eliminate the local indeterminacy of the intended steady state, and (c) nominal rigidities and inincomplete markets are complementary in terms of amplifying the impact of shocks on the macroeconomy.
What Every Neuropathologist Needs to Know: The Muscle Biopsy
Authors: Nix James S , Moore Steven A
Published: June 2020

Competence in muscle biopsy evaluation is a core component of neuropathology practice. The practicing neuropathologist should be able to prepare frozen sections of muscle biopsies with minimal artifacts and identify key histopathologic features of neuromuscular disease in hematoxylin and eosin-stained sections as well as implement and interpret a basic panel of additional histochemical, enzyme histochemical, and immunohistochemical stains. Important to everyday practice is a working knowledge of normal muscle histology at different ages, muscle motor units, pitfalls of myotendinous junctions, nonpathologic variations encountered at traditional and nontraditional muscle sites, the pathophysiology of myonecrosis and regeneration, and approaches to distinguish muscular dystrophies from inflammatory myopathies and other necrotizing myopathies. Here, we provide a brief overview of what every neuropathologist needs to know concerning the muscle biopsy.
The Changing Aesthetics of Vocal Registration in the Age of ‘Verismo’
Authors: Gentili Barbara
Published: June 2020

The idea that classical singers should join the notes of the vocal line by maintaining a consistent vocal colour is a relatively recent historical construct. In the last decades of the nineteenth century, singers in the Italian tradition were loyal to a very different vocal aesthetic, which valued the distinct differences in timbre between different vocal registers, as this article shows through a comparative analysis of pedagogical writing and pre-1925 recordings. The latter reveal that, in the early twentieth century, old and new techniques for uniting the vocal registers coexisted, and reflected an aesthetic transition towards a more gendered quality of the operatic voice. This process was intertwined with profound transformations in Italian operatic culture. The demands of a new realistic idiom known as verismo required a new type of vocalism, which prompted singers to re-conceive the ‘art of vocal registration’.
On the development of a rotated-hybrid HLL/HLLC approximate Riemann solver for relativistic hydrodynamics
Authors: Townsend Jamie F , Könözsy László , Jenkins Karl W
Published: June 2020

This work presents the development of a rotated-hybrid Riemann solver for solving relativistic hydrodynamics (RHD) problems with the hybridization of the HLL and HLLC (or Rusanov and HLLC) approximate Riemann solvers. A standalone application of the HLLC Riemann solver can produce spurious numerical artefacts when it is employed in conjunction with Godunov-type high-order methods in the presence of discontinuities. It has been found that a rotated-hybrid Riemann solver with the proposed HLL/HLLC (Rusanov/HLLC) scheme could overcome the difficulty of the spurious numerical artefacts and presents a robust solution for the Carbuncle problem. The proposed rotated-hybrid Riemann solver provides sufficient numerical dissipation to capture the behaviour of strong shock waves for RHD. Therefore, in this work, we focus on two benchmark test cases (odd–even decoupling and double-Mach reflection problems) and investigate two astrophysical phenomena, the relativistic Richtmyer–Meshkov instability and the propagation of a relativistic jet. In all presented test cases, the Carbuncle problem is shown to be eliminated by employing the proposed rotated-hybrid Riemann solver. This strategy is problem-independent, straightforward to implement and provides a consistent robust numerical solution when combined with Godunov-type high-order schemes for RHD.
On the relative importance of hadronic emission processes along the jet axis of active galactic nuclei
Authors: Hoerbe Mario R , Morris Paul J , Cotter Garret , Becker Tjus Julia
Published: June 2020

With the coincident detection of a gamma-ray flare and a neutrino from the blazar TXS 0506+056, active galactic nuclei (AGNs) have been put into focus as possible sources of the diffuse neutrino flux. We present a space and time-resolved model of the high-energy particle emission of a plasmoid assumed to travel along the axis of an AGN jet at relativistic speed. This was achieved by modifying the publicly available crpropa (version 3.1+) propagation framework that in our work is capable of being applied to source physics on sub-kpc scales. The propagation of a population of primary protons is modelled in a purely turbulent magnetic field and we take into account interactions of these protons with photons scattered from the accretion disc, synchrotron radiation emitted by ambient relativistic electrons, as well with themselves and with other ambient matter. Our model produces a PeV-neutrino flare caused mainly by photohadronic interactions of primaries with the accretion disc field. Secondary high-energy gamma-rays partly attenuate with the ambient photon fields whose combined optical depths achieve their minimal opacity for photons of around 10 TeV. Thus, our model is well capable of producing neutrino flares with a significantly reduced emission of gamma-rays in jets with a hadronic jet component that in the future can be fit to specific AGN flare scenarios.
Evidence of large-scale energy cascade in the spiral galaxy NGC 5236
Authors: Nandakumar Meera , Dutta Prasun
Published: June 2020

Turbulence plays an important role in the structure and dynamics of the galaxy and influences various processes therein including star formation. In this work, we investigate the large-scale turbulence properties of the external spiral galaxy NGC 5236. We combine the Very Large Array (VLA) multiconfiguration archival data with the new GMRT observation to estimate the column density and line-of-sight velocity fluctuation power spectra for this galaxy over almost two decades of length scales. The energy input scale to the interstellar medium turbulence is found to be around 6 kpc. Power spectra of the two-dimensional turbulence in the galaxy’s disc follow a power law with a slope −1.23 ± 0.06 for the column density and −1.91 ± 0.08 for the line-of-sight velocity. The measured power spectra slopes strongly suggest in favour of a compressive forcing with a steady energy input of ∼7 × 10−11   erg cm −2 s−1. We conclude that much of these originate from the gravitational instabilities and self-gravity in the disc. This is the first and most comprehensive study of turbulence statistics for any external spiral galaxy.
The lively accretion disc in NGC 2992 – I. Transient iron K emission lines in the high-flux state
Authors: Marinucci A , Bianchi S , Braito V , De Marco B , Matt G , Middei R , Nardini E , Reeves J N
Published: June 2020

We report on one of the brightest flux levels of the Seyfert 2 galaxy NGC 2992 ever observed in X-rays, on 2019 May. The source has been monitored every few days from 2019 March 26 to 2019 December 14 by Swift-X-Ray Telescope (XRT), and simultaneous XMM–Newton (250 ks) and NuSTAR (120 ks) observations were triggered on 2019 May 6. The high count rate of the source (its 2–10 keV flux ranged between 0.7 and 1.0 × 10−10 erg cm−2 s−1) allows us to perform a time-resolved spectroscopy, probing spatial scales of tens of gravitational radii from the central black hole. By constructing a map of the excess emission over the primary continuum, we find several emission structures in the 5.0–7.2 keV energy band. From fitting the 50 European Photon Imaging Camera (EPIC)-pn spectral slices of ∼5 ks duration, we interpret them as a constant narrow iron Kα line and three variable components in the iron K complex. When a self-consistent model accounting for the accretion disc emission is considered (KYNrline), two of these features (in the 5.0–5.8 and 6.8–7.2 keV bands) can be ascribed to a flaring region of the accretion disc located at rin ≃ 15–40rg from the black hole. The third one (6.5–6.8 keV) is likely produced at much larger radii (rin > 50rg). The inner radius and the azimuthal extension retrieved from the co-added spectra of the flaring states are rin = 15 ± 3rg and ϕ = 165°–330°, suggesting that the emitting region responsible for the broad iron K component is a relatively compact annular sector within the disc. Our findings support a physical scenario in which the accretion disc in NGC 2992 becomes more active at high accretion rates ($L_{\rm bol}/L_{\rm Edd}\ge 4$ per cent).
Discovery and astrophysical properties of Galactic open clusters in dense stellar fields using Gaia DR2
Authors: Ferreira F A , Corradi W J B , Maia F F S , Angelo M S , Santos J F C
Published: June 2020

We report the discovery of 25 new open clusters resulting from a search in dense low Galactic latitude fields. We also provide, for the first time, structural and astrophysical parameters for the new findings and 34 other recently discovered open clusters using Gaia Data Release 2 (DR2) data. The candidates were confirmed by jointly inspecting the vector point diagrams and spatial distribution. The discoveries were validated by matching near known objects and comparing their mean astrometric parameters with the available literature. A decontamination algorithm was applied to the three-dimensional astrometric space to derive membership likelihoods for clusters stars. By rejecting stars with low membership likelihoods, we built decontaminated colour–magnitude diagrams and derived the clusters astrophysical parameters by isochrone fitting. The structural parameters were also derived by King-profile fittings over the stellar distributions. The investigated clusters are mainly located within 3 kpc from the Sun, with ages ranging from 30 Myr to 3.2 Gyr and reddening limited to E(B − V) = 2.5. On average, our cluster sample presents less concentrated structures than Gaia DR2 confirmed clusters, since the derived core radii are larger while the tidal radii are not significantly different. Most of them are located in the IV quadrant of the Galactic disc at low latitudes, therefore, they are immersed in dense fields characteristic of the inner Milky Way.
Towards climate resilient urban energy systems: a review
Authors: Nik Vahid M , Perera A T D , Chen Deliang
Published: June 2020

Climate change and increased urban population are two major concerns for society. Moving towards more sustainable energy solutions in the urban context by integrating renewable energy technologies supports decarbonizing the energy sector and climate change mitigation. A successful transition also needs adequate consideration of climate change including extreme events to ensure the reliable performance of energy systems in the long run. This review provides an overview of and insight into the progress achieved in the energy sector to adapt to climate change, focusing on the climate resilience of urban energy systems. The state-of-the-art methodology to assess impacts of climate change including extreme events and uncertainties on the design and performance of energy systems is described and discussed. Climate resilience is an emerging concept that is increasingly used to represent the durability and stable performance of energy systems against extreme climate events. However, it has not yet been adequately explored and widely used, as its definition has not been clearly articulated and assessment is mostly based on qualitative aspects. This study reveals that a major limitation in the state-of-the-art is the inadequacy of climate change adaptation approaches in designing and preparing urban energy systems to satisfactorily address plausible extreme climate events. Furthermore, the complexity of the climate and energy models and the mismatch between their temporal and spatial resolutions are the major limitations in linking these models. Therefore, few studies have focused on the design and operation of urban energy infrastructure in terms of climate resilience. Considering the occurrence of extreme climate events and increasing demand for implementing climate adaptation strategies, the study highlights the importance of improving energy system models to consider future climate variations including extreme events to identify climate resilient energy transition pathways.
Human variation in response to food and nutrients
Authors: Head Richard J , Buckley Jonathan D
Published: June 2020

The application of science to human nutrition over the centuries has served societies well. One example is the identification of key nutrients to overcome nutritional deficiencies, which has enhanced life expectancy. Enhanced life expectancy, however, is associated with an increased prevalence of chronic disorders related to food and nutrition. Findings of studies indicating that individual responses to nutrients differ substantially between individuals make it necessary to re-examine the relationship between nutrition and human health. The emergence of new genomic-based technologies illustrates the complexity and scale of the interactions between nutrition and genetic factors. Epigenetic modifications resulting from interactions of the genetic profile, aging, and lifestyle can influence the time course of chronic disorders and contribute to human variability in response to nutritional interventions. Developing a better understanding of human variability as it applies to human nutrition will involve embracing the approaches and principles of complex science.
Recent developments in the history of economics
Authors: Backhouse Roger E , Forder James
Published: June 2020

This volume contains a small sample of papers presented to the fiftieth UK History of Economic Thought Conference, held at Balliol College, Oxford, on 29–31 August 2018. Over forty papers were presented, and this special issue contains nine of the thirty-one submitted for possible publication.
Coronavirus 2019 Silver Linings
Authors: Santosa Amelia , Cross Gail , Oon Jolene Ee Ling , Archuleta Sophia , Dan Yock Young
Published: June 2020

A heightened state of alert due to the Coronavirus Disease 2019 (COVID-19) outbreak was declared by the Singapore Ministry of Health on February 7, 2020. Within the hospital, team reorganizations, workflow revisions, and physical segregation caused anxiety among healthcare workers (HCWs). Fear of the unknown and emotional and physical fatigue started to take their toll on HCWs. We share our learning journey over the first 8 weeks of COVID-19: the importance of acknowledging fears and questions, and transforming them to collective knowledge; the role of empathic, hands-on leadership that brings camaraderie and calms scepticism; the importance of validating efforts and acknowledging hardship; and, most importantly, the security that comes from camaraderie, breaking down hierarchical barriers, and motivating each other to keep on going.
The Effectiveness of Cervical Medial Branch Thermal Radiofrequency Neurotomy Stratified by Selection Criteria: A Systematic Review of the Literature
Authors: Engel Andrew , King Wade , Schneider Byron J , Duszynski Belinda , Bogduk Nikolai
Published: June 2020

Objective

To determine the effectiveness of cervical medial branch thermal radiofrequency neurotomy in the treatment of neck pain or cervicogenic headache based on different selection criteria.

Design

Comprehensive systematic review.

Methods

A comprehensive literature search was conducted, and the authors screened and evaluated the studies. The Grades of Recommendation, Assessment, Development, and Evaluation system was used to assess all eligible studies.

Outcome Measures

The primary outcome measure assessed was the success rate of the procedure, defined by varying degrees of pain relief following neurotomy. Data are stratified by number of diagnostic blocks and degree of pain relief.

Results

Results varied by selection criteria, which included triple placebo-controlled medial branch blocks, dual comparative medial branch blocks, single medial branch blocks, intra-articular blocks, physical examination findings, and symptoms alone. Outcome data showed a greater degree of pain relief more often when patients were selected by triple placebo-controlled medial branch blocks or dual comparative medial branch blocks, producing 100% relief of the index pain. The degree of pain relief was similar when triple or dual comparative blocks were used.

Conclusions

Higher degrees of relief from cervical medial branch thermal radiofrequency neurotomy are more often achieved, to a statistically significant extent, if patients are selected on the basis of complete relief of index pain following comparative diagnostic blocks. If selected based on lesser degrees of relief, patients are less likely to obtain complete relief.
Misallocation in the Market for Inputs: Enforcement and the Organization of Production*
Authors: Boehm Johannes , Oberfield Ezra
Published: June 2020

The strength of contract enforcement determines how firms source inputs and organize production. Using microdata on Indian manufacturing plants, we show that production and sourcing decisions appear systematically distorted in states with weaker enforcement. Specifically, we document that in industries that tend to rely more heavily on relationship-specific intermediate inputs, plants in states with more-congested courts shift their expenditures away from intermediate inputs and have a greater vertical span of production. To quantify the effect of these distortions on aggregate productivity, we construct a model in which plants have several ways of producing, each with different bundles of inputs. Weak enforcement exacerbates a holdup problem that arises when using inputs that require customization, distorting both the intensive and extensive margins of input use. The equilibrium organization of production and the network structure of input-output linkages arise endogenously from the producers’ simultaneous cost-minimization decisions. We identify the structural parameters that govern enforcement frictions from cross-state variation in the first moments of producers’ cost shares. A set of counterfactuals show that enforcement frictions lower aggregate productivity to an extent that is relevant on the macro scale.
INTERNAL CHANDELIER-ASSISTED MACULAR BUCKLING FOR MYOPIC FOVEOSCHISIS
Authors: Grewal Parampal S. , Seamone Mark , Greve Mark , Deveau Adam , Gupta R. Rishi
Published: June 2020

Purpose:

To present a surgical technique and case presentation of internal chandelier-assisted macular buckling for myopic foveoschisis.

Methods:

Review of patient clinical features, visual acuity, and optical coherence tomography results after internal chandelier-assisted macular buckling for myopic foveoschisis.

Results:

A 48-year-old highly myopic woman (axial length 29.85 mm) underwent internal chandelier-assisted macular buckling for myopic foveoschisis with macular detachment. The best-corrected visual acuity improved from 20/150 to 20/40. Postoperative optical coherence tomography confirmed central buckle positioning and demonstrated resolved foveoschisis and macular detachment. There were no complications.

Conclusion:

Internal chandelier-assisted macular buckling is a valuable tool to optimize buckle position and patient outcomes.
An Assessment of Clinical and System Drivers of Family Satisfaction in the PICU*
Authors: Hummel Kevin , Presson Angela P. , Millar Morgan M. , Larsen Gitte , Kadish Howard , Olson Lenora M.
Published: June 2020

Objective:

Investigate clinical and system drivers of family satisfaction in the PICU.

Design:

Mixed methods qualitative and quantitative (observational) study. Qualitative interviews with families were performed as a pilot to inform modality of survey distribution based on family preferences. A validated pediatric satisfaction survey deployed to family members for 7 months with a corresponding chart review and administrative data collection.

Setting:

PICU in a tertiary children’s hospital.

Patients:

Two hundred six families of patients admitted to the PICU more than 48 hours.

Interventions:

None.

Measurements and Main Results:

Families preferred surveys distributed electronically on a tablet in the PICU setting. The Pediatric Family Satisfaction-ICU survey was used to assess comfort with medical decision-making and communication with the care team. Capture rate of all eligible patients was 69.5% and response rate was 90.8%. Overall, 64.7% of respondents were highly satisfied, whereas over one third were not highly satisfied; families of Hispanic ethnicity (odds ratio of lower satisfaction of families with Hispanic ethnicity: 2.09; 95% CI, 1.01–4.33; p = 0.047) and high social stressors (odds ratio of higher satisfaction among high stressed subgroup: 0.49; 95% CI, 0.24–0.99; p = 0.047) reported statistically significant lower satisfaction. Additional free-text responses were identified in 21% of respondents, with the majority of comments indicating wishes for improvements clustered around communication with the medical team or sleeping environment of families and patients.

Conclusions:

High capture rates of family satisfaction in the PICU can be obtained with a PICU-specific survey, limiting barriers to completion by including family preferences, and distributing in the PICU setting. Less than two-third of PICU families are highly satisfied; patients of Hispanic ethnicity and those with high social stressors predict low satisfaction, whereas illness severity, age, and PICU length of stay did not have statistical significance. Local improvement teams can use this approach to drive enhanced satisfaction.