bluuebunny/crossref_metadata_2025 huggingface dataset:
Real-time single-frequency multi-GNSS positioning with ultra-rapid products
Authors: Bahadur Berkay , Nohutcu Metin
Published: July 2020

Ultra-rapid products, which do not require any external connection unlike real-time services, are an important alternative for real-time global navigation satellite system (GNSS) applications. Especially, the inclusion of newly-emerged satellite systems in ultra-rapid products opens up considerable opportunities to improve the positioning performance. In this regard, this study concentrates on the employment of the most recent ultra-rapid products besides traditional ones for real-time single-frequency multi-GNSS positioning using code and carrier phase measurements. In the study, experimental tests were conducted for the ionosphere-free code-carrier combination to evaluate the performance of single-receiver single-frequency positioning. The results reveal that single-frequency positioning is able to provide sub-meter level positioning accuracy with ultra-rapid products despite its performance alters depending on the applied product. Also, the performance of single-frequency positioning which based on code-carrier combination is not influenced significantly from the possible decline in the precision of ultra-rapid products over time due to the convergence of phase ambiguities. On the other hand, the results demonstrate that the accuracy of pseudorange positioning can significantly be improved with the integration of multi-constellation and the improvement ratio can reach 30% compared with the GPS-only solutions. Furthermore, the convergence time of GPS-only solution can be decreased by a ratio of 37% on average with multi-GNSS combinations. Finally, the results show that for the multi-constellation analyses, the solutions which utilize the ultra-rapid product of Wuhan University provide the best performance in terms of positioning accuracy and convergence time.
Direct determination of

kB⃗,Q,Q0

for cylindrical ionization chambers in a 6 MV 0.35 T MR-linac
Authors: Krauss A , Spindeldreier C K , Klüter S
Published: July 2020

To ensure accurate reference dosimetry with ionization chambers in magnetic resonance linear accelerators (MR-linacs), the influence of the magnetic field on the response of the ionization chambers must be considered. The most direct method considering the influence of magnetic fields in dosimetry is to apply an appropriate absorbed-dose-to-water primary standard. At PTB, a new water calorimeter has been designed which is capable to determine Dw,Q
in an MR-linac. The new device allows the direct calibration of ionization chambers in terms of absorbed dose to water for MR-linac irradiation conditions. Hence, the correction factors

k

B
⃗

,
Q
,

Q
0

can be determined which replace the current radiation-quality dependent correction factors

k

Q
,

Q
0

for dosimetry in the presence of magnetic fields. In cooperation with Heidelberg University Hospital,

 

k

B
⃗

,
Q
,

Q
0

factors were measured at the 6 MV 0.35 T Viewray MR-linac for different cylindrical ionization chambers with sensitive volumes ranging from 0.015 cm3 to 0.65 cm3. The chambers were placed both perpendicular and parallel in respect to the magnetic field. Standard uncertainties of about 0.5% were achieved.
Comparison of different modulations of photoplethysmography in extracting respiratory rate: from a physiological perspective
Authors: Liu Haipeng , Chen Fei , Hartmann Vera , Khalid Syed Ghufran , Hughes Stephen , Zheng Dingchang
Published: July 2020

Objective: Based on different physiological mechanisms, the respiratory modulations of photoplethysmography (PPG) signals differ in strength and resultant accuracy of respiratory frequency (RF) estimations. We aimed to investigate the strength of different respiratory modulations and the accuracy of resultant RF estimations in different body sites and two breathing patterns. Approach: PPG and reference respiratory signals were simultaneously measured over 60 s from 36 healthy subjects in six sites (arm, earlobe, finger, forehead, wrist-under (volar side), wrist-upper (dorsal side)). Respiratory signals were extracted from PPG recordings using four demodulation approaches: amplitude modulation (AM), baseline wandering (BW), frequency modulation (FM) and filtering. RFs were calculated from the PPG-derived and reference respiratory signals. To investigate the strength of respiratory modulations, the energy proportion in the range that covers 75% of the total energy in the reference respiratory signal, with RF in the middle, was calculated and compared between different modulations. Analysis of variance and the Scheirer–Ray–Hare test were performed with post hoc analysis. Main
results: In normal breathing, FM was the only modulation whose RF was not significantly different from the reference RF (p > 0.05). Compared with other modulations, FM was significantly higher in energy proportion (p < 0.05) and lower in RF estimation error (p < 0.05). As to energy proportion, measurements from the finger and the forehead were not significantly different (p > 0.05), but both were significantly different from the other four sites (p < 0.05).
In deep breathing, the RFs derived by BW, filtering and FM were not significantly different from the reference RF (p > 0.05). The RF estimation error of FM was significantly less than that of AM or BW (p < 0.05). The energy proportion of FM was significantly higher than that of other modulations (p < 0.05). Significance: Of all the respiratory modulations, FM has the highest strength and is appropriate for accurate RF estimation from PPG signals recorded at different sites and for different breathing patterns.
The formation of atomic oxygen and hydrogen in atmospheric pressure plasmas containing humidity: picosecond two-photon absorption laser induced fluorescence and numerical simulations
Authors: Schröter Sandra , Bredin Jérôme , Gibson Andrew R , West Andrew , Dedrick James P , Wagenaars Erik , Niemi Kari , Gans Timo , O’Connell Deborah
Published: July 2020

Atmospheric pressure plasmas are effective sources for reactive species, making them applicable for industrial and biomedical applications. We quantify ground-state densities of key species, atomic oxygen (O) and hydrogen (H), produced from admixtures of water vapour (up to 0.5%) to the helium feed gas in a radio-frequency-driven plasma at atmospheric pressure. Absolute density measurements, using two-photon absorption laser induced fluorescence, require accurate effective excited state lifetimes. For atmospheric pressure plasmas, picosecond resolution is needed due to the rapid collisional de-excitation of excited states. These absolute O and H density measurements, at the nozzle of the plasma jet, are used to benchmark a plug-flow, 0D chemical kinetics model, for varying humidity content, to further investigate the main formation pathways of O and H. It is found that impurities can play a crucial role for the production of O at small molecular admixtures. Hence, for controllable reactive species production, purposely admixed molecules to the feed gas is recommended, as opposed to relying on ambient molecules. The controlled humidity content was also identified as an effective tailoring mechanism for the O/H ratio.
Low-temperature positive magnetoresistance in ZnO-based heterostructures
Authors: Ma X R , Zhang X H , Gao Y F , Li Q L , Gao K H
Published: July 2020

The positive magnetoresistance (MR) usually appears at cryogenic temperature in ZnO-based transport systems, the origin of which is reported to be related to the localized magnetic moment. Here we find a different origin of the positive MR in Zn1−x
Mg
x
O/ZnO heterostructures prepared by magnetron sputtering. The large positive MR is observed in all samples at 2 K. On increasing temperature, the observed positive MR is gradually suppressed and transformed into the negative MR at higher temperature. Similarly, the suppression of the positive MR also occurs in the samples with the higher electron density. The experimental data can be well described by applying a two-band model combined with the weak localization (WL) theory. This indicates that the observed positive MR originates from the impurity-band-related two-band transport, while the observed negative MR arises from the WL.
Multi-label learning for improving discretely-modulated continuous-variable quantum key distribution
Authors: Liao Qin , Xiao Gang , Zhong Hai , Guo Ying
Published: July 2020

We propose a novel scheme for discretely-modulated continuous-variable quantum key distribution (CVQKD) using machine learning technologies, which called multi-label learning-based CVQKD (ML-CVQKD). In particular, the proposed scheme divides the whole quantum system into state learning process and state prediction process. The former is used for training and estimating classifier, and the latter is used for generating final secret key. Meanwhile, a multi-label classification algorithm (MLCA) is also designed as an embedded classifier for distinguishing coherent state. Feature extraction for coherent state and related machine learning-based metrics for the quantum classifier are successively suggested. Security analysis based on the linear bosonic channel assumption shows that MLCA-embedded ML-CVQKD outperforms other existing discretely-modulated CVQKD protocols, such as four-state protocol and eight-state protocol, as well as the original Gaussian-modulated CVQKD protocol, and it will be further enhanced with the increase of modulation variance.
Dynamical structure factors of a two-dimensional Fermi superfluid within random phase approximation
Authors: Zhao Huaisong , Gao Xiaoxu , Liang Wen , Zou Peng , Yuan Feng
Published: July 2020

Based on random phase approximation, we numerically calculate dynamical structure factors of a balanced two-dimensional (2D) Fermi superfluid, and discuss their energy, momentum and interaction strength dependence in the 2D BEC–BCS crossover. At a small transferred momentum, a stable Higgs mode is observed in the unitary 2D Fermi superfluid gas where the particle–hole symmetry is not satisfied. Stronger interaction strength will make the visibility of the dispersion of Higgs mode harder to be observed. We also discuss the dimension effect and find that the signal of the Higgs mode in two dimension is more obvious than that in 3D case. At a large transferred momentum regime, stronger interaction strength will induce the weight of the molecules excitation increasing, while in verse the atomic one decreasing, which shows the pairing information of Fermi superfluid. The theoretical results qualitatively agree with the corresponding quantum Monte Carlo data.
Ecological building design based on the optimization of thermal performance of stilt houses in Guangxi Province
Authors: Jimin Zhong , Jiang He , Xiang Lv
Published: July 2020

Traditional stilt houses in Guangxi Province are ventilated and breathable in summer with good dehumidification and heat insulation performance. In winter, however, their airtightness and thermal insulation abilities are relatively poor. In order to analyze the advantages and disadvantages of the thermal performance of stilt houses in Guangxi Province, this study designs four ecological buildings: Building A is a traditional stilt house with a sloping roof and wooden fences; Building B is a reinforced concrete structured house with a flat roof; Building C is a reinforced concrete structured house with a sloping roof and surrounding self-insulating blocks; Building D has the same conditions as C, except its louvers. Through the Swire energy consumption simulation, we can obtain an ideal multi-layer ecological civil building with a thermal-insulation top layer that can be opened as well as louvers and self-insulating blocks used for the outer wall.
Research of Three-Dimension Design in Infrastructure Project Application
Authors: Lin Xing , Wang Ning , Linjie Chai , Hongmei Zhang , Nan Cheng
Published: July 2020

The three-dimensional design of transmission and transformation projects is a new development trend of State Grid Corporation. This article examines the key technical and management constraints of three-dimensional design of transmission and transformation projects from multiple perspectives, and uses three-dimensional design results to carry out exploration and control of construction process. Accumulate experience from collision testing, simulation construction, cost saving, time saving and dynamic management and control of materials and equipment resources to form a three-dimensional construction management and control measure for power transmission and transformation projects. By building the engineering data platform of Hebei Company, the design-infrastructure-operation and maintenance integration is realized. Provide a platform for storage, display and interaction for data sharing and integration in design, construction and operation. Realize the three-dimensional integration, monitoring and analysis of power grid information. To achieve the goal of comprehensively improving the technical and management level of the design and management of transmission and transformation projects of Hebei Company, and to promote the application of digital results in the design of transmission and transformation projects of Hebei Company.
Sound attenuation performance of periodic expansion chamber mufflers
Authors: Shi Xiaofeng
Published: July 2020

Expansion chamber mufflers are often used for duct noise control of building ventilation systems. In this paper, the periodic arrangement of expansion chamber muffler is proposed to improve the sound attenuation performance. The sound attenuation of periodic expansion chamber mufflers is investigated theoretically with Bloch wave theory and a case is calculated for the distance between mufflers and the length of the expansion chamber are the same. The results reveal that the transmission loss of the expansion muffler is enhanced by the periodic arrangement.
Experimental research on failure mode of reinforced concrete beams under contact explosion
Authors: Wang Huiming , Liu Fei , Wang Jianhui , Yan Luhui , Lv Linmei , Shan Wei
Published: July 2020

In order to research the failure mode of reinforced concrete(RC) beams under contact explosion, experiments were carried out to explore the damage of RC prototype beams fixed at both ends under four TNT charge masses, the damage failure model and damage effect of RC beams under different charge masses were analyzed. The results show that the beam presents three local failure modes: crater damage, collapse, spall failure and punching failure. The degree of local damage has a serious impact on the overall bending deformation of the beam. Besides, reasonable reinforcement could effectively improve the anti-explosion performance of the beam. The research results could provide a theoretical basis for the design of the anti-blast structures and the damage analysis on the structure subjected to explosive action.
Research on synthesis and property of anti-clay polycarboxylate superplasticizer
Authors: Xiong Qiumin , Chen Xiaobin , Dang Wei , Guo Xiujuan , Xu Han , Li Guangzhou , Guan Jican , Huang Xiaohu
Published: July 2020

With isopentenyl polyoxyethylene polyether (TPEG), maleic anhydride (MAH), acrylic acid (AA) and binary ester (DBE) as monomers, hydrogen peroxide (H2O2) as initiator and mercaptoacetic acid (MAA) as chain transfer agent, the anti-clay polycarboxylate superplasticizer (APC) was synthesized. The structure of polymer was characterized by infrared spectroscopy (FTIR) and gel permeation chromatography (GPC). The fluidity of cement paste mixed with montmorillonite (MMT) and the slump of concrete were used as evaluation indicators to investigate its mud resistance and dispersion properties. The results showed that when the content of bentonite (MMT) in the cement was 3% and the content of APC was 0.15% of the cement quality, the initial fluidity of the cement paste was 235 mm and the fluidity in 2 hours was 187 mm. The concrete test was carried out with the machine-made sand with high mud content: the slump flow was 560 mm, and the slump flow was 500 mm after 2 hours. APC has good mud resistance and good dispersion and retention properties.
Seepage control effect of a concrete face rockfill dam on a deep overburden foundation
Authors: Wen Lifeng , Li Yanlong
Published: July 2020

This study addresses the seepage field characteristics of a concrete face rockfill dam (CFRD) built on a deep overburden foundation. The seepage barriers and anti-seepage effect for the dam and foundation are analysed using the finite element method (FEM). Based on the numerical analysis, it is concluded that the anti-seepage wall in the overburden foundation can achieve good anti-seepage effect. A relative depth ratio of 0.7 between the wall and overburden is suggested when a suspended cut-off wall is used. The permeability of the overburden has a significant effect on the foundation seepage field.
Near-surface Temperature Inversion over the East China Sea
Authors: Zhang Zhiwei , Li Yunying
Published: July 2020

Temperature inversion structure affects the boundary layer activity and convective activity. The frequency, strength, and formation mechanism of near-surface temperature inversion are studied using sounding data at three stations over the East China Sea from 2000 to 2015. The results show that the frequency and strength of the inversion are larger in summer (over Cheju station) than in winter (over ROIG station). The inversion is mainly classified as advection inversion over Cheju station, while mainly classified as radiation inversion over ROIG station. Low cloud amount in winter is larger than that in summer over the East China Sea, which is opposite to the inversion frequency. The reason is that the frequent and strong inversions hinder the height of convection in summer, it is difficult for moist air to reach the lifting condensation level and form clouds.
Review and feasibility analysis of prefabricated recycled concrete structure
Authors: Ma X C , Luo W J , Yin J
Published: July 2020

Recycled concrete is a resource utilization technology of building rubbish, which is of great significance to environmental protection and socio-economics. And because prefabricated structure buildings adopt standardized design, factory production, information management, assembly construction and intelligent applications, it can meet the needs of sustainable development. The combination of these two technologies can give full play to the environmental advantages of this structure. This article starts from the three aspects of work performance, mechanical performance and anti-seismic performance, and summarizes the research status and analyzes the feasibility of applying recycled concrete to prefabricated structures to promote the further integration of these two environmentally friendly construction technologies.
Influence of Valve Core Structure on Flow Rate and Internal Flow Field of Pressure Independent Control Valve
Authors: Fan Y L , Wang J , Huang J , Peng L , Li Z
Published: July 2020

To study the influence of valve core structure on pressure independent control valve, based on the computational fluid dynamics method, the 3D model of pressure independent control valve under different control valve core structure is established. Then the influence of different control core structure on valve flow rate under different pressure was studied, the pressure and velocity distribution of the internal flow field are obtained. The results show that, under the same flow characteristics, a maximum flow capacity under different valve core difference of 20%, the pressure and velocity distribution of the internal flow field is different. Reasonable choice of different valve core structures for different working conditions can improve the stability of the flow field in the valve.
Comparative study on calculation methods of wave force on breast wall in Chinese, Japanese and European codes
Authors: Jian Huang , Xiu-min Zhang , Xiao Bing , Li-hong Dong , Yun Peng
Published: July 2020

The stability calculation of breast wall is an important content in the design of slope marine structures. The main damage load of breast wall on rubble-mound breakwater is wave force. In the absence of physical model test data, wave force is often differently calculated according to the methods specified in the different codes and design manuals. In this paper, different calculation methods for wave force based on the codes of China, Japan and Europe are discussed and analyzed. Then, a revetment project in Africa is taken as an example to compare the calculation results. Finally, important conclusions can be obtained that (1) the results calculated by the Chinese code are relatively reasonable; (2) When calculating the wave force imposed on breast wall placed on vertical wall, the Goda’s method in the Japanese code is practicable. As for the relevant calculation of the wave force on slope structures, it can only be used for approximate estimation. (3) In the method of BS6349, the range of K value is relatively large, which has great influence on the calculation results. When using this method, more attention should be paid to the selection of K value. The results can provide a reference for structure design of breast wall without physical model test data.
Research on the Application of BIM + VR Technology in the Project
Authors: Wu Bei , Chen Yanxiu , You Yang , Liu Liping , Gao Zhanwang
Published: July 2020

At present, the research of BIM + VR technology is the forefront of BIM technology application research. BIM technology can solve some design problems and provide collaborative design solutions for various professions. Virtual reality technology (VR) technology can make up for some of the shortcomings of BIM technology BIM technology and VR technology can complement each other and be used in actual engineering projects. For this case, the actual application results show that BIM + VR technology can effectively solve the visualized expression of the integrated design of the interior pipe of the building, the decorative design and management.
Study on the mixing and separation of UHF signals with multiple insulation defects in GIS
Authors: Zhao Xiaoxiao , Mu Wei , Yun Yuxin
Published: July 2020

In order to explore the mixing characteristics of ultra-high frequency (UHF) partial discharge (PD) signals in GIS, simulation tools and Antenna Theory concerning the electromagnetic field (XFDTD) have been adopted in investigating the mixed features of UHF signals in GIS environment. Simulation results and theoretical analysis in this paper demonstrate that convolution is the basic relationship between PD current signal and the single UHF PD signal; the PD mixing signals are the linear and instantaneous mixture of single PD signals and they are also the linear and convolution mixture of PD current signals. The reverse process of those mixing modes are also been discussed based on blind sources separation and find out that it is an over complete blind source separation problem to gain single UHF PD signal from mixed one. Moreover, it can be approximated to conventional blind source separation when the layout of ultra-high frequency sensors is compact.
Spectral-detector based x-ray absorptiometry (SDXA): in-vivo bone mineral density measurements in patients with and without osteoporotic fractures
Authors: Laugerette Alexis , Baum Thomas , Gersing Alexandra S , Schwaiger Benedikt J , Brown Kevin , Frerking Lena C , Shapira Nadav , Pfeiffer Daniela , Rummeny Ernst J , Proksa Roland , Pfeiffer Franz , Noël Peter B
Published: July 2020

Objectives: To study whether a dual-layer spectral CT scout scan-based areal BMD estimation method, called Spectral-detector based x-ray absorptiometry (SDXA), can differentiate patients with versus without osteoporotic fractures. Methods: The ability of the method to differentiate patients with osteoporosis was evaluated by assessing the areal BMD at the spine (L1 to L4) in a group of 19 patients presenting at least one fracture and comparing these results to the areal BMD of age- and gender-matched controls (57 patients). Finally, the reproducibility of SDXA was evaluated in-vivo through the calculation of coefficients of variation (CV), using three repeated analyses performed on each patient. Results: The average areal BMD of patients presenting fractures, measured with the scout scan-based method (0.86 ± 0.17 g cm−2), was found to be significantly lower than the average BMD of the control group (1.00 ± 0.17 g cm−2, p = 0.043). The reproducibility of the method in-vivo was found to be reasonable, with CVs ranging between 3.1 and 6.9%. Conclusions: The results illustrate that the SDXA method for DXA-equivalent areal BMD estimation -delivers the ability to distinguish patients presenting osteoporotic fractures. Considering the total number of CT examinations worldwide, SDXA could develop to be a useful tool for truly opportunistic osteoporosis screening for a future clinical day-to-day routine.
Resolution of the Plane-symmetric Einstein-Maxwell fields with a generalization of the Lambert W function
Authors: Mező István , Corcino Cristina B , Corcino Roberto B
Published: July 2020

Here, the Einstein-Maxwell field equation with plane-symmetry is resolved and a solution involving a generalized Lambert W function is obtained. This generalized Lambert W function is studied and its derivative, Taylor series, Mellin transform and approximation formula are derived and its real branches are determined. Implications of these analytic properties to the solution function are also presented.
Design of a motorised plasma delivery system for ultra-precision large optical fabrication
Authors: Zhou Hui , Bennett Adam , Castelli Marco , Jourdain Renaud , Guo Jiang , Yu Nan
Published: July 2020

A unique plasma figuring (PF) process was created and demonstrated at Cranfield University for manufacturing extremely large telescopes. The atmospheric pressure processing is faster and more cost-effective than other finishing processes; thus, providing an important alternative for large optical surfaces. The industrial scale manufacturing of thousands of ultra-precision metre-scale optics requires a robust PF machine: this requirement is achieved by making the plasma delivery system (PDS) performance repeatable. In this study, a dedicated PDS for large optical manufacturing was proposed to meet the industrial requirement. The PDS is based on an L-type radiofrequency (RF) network, a power supply, and an inductively coupled plasma torch. However, the complexities of these technologies require an in depth understanding of the integrated components that from the PDS. A smart control system for the modified PDS was created. This novel control system aims to make the characterization process deterministic: by automating the tuning of critical electrical components in the RF network, which is achieved by the use of in-line metrology. This paper describes the main design aspects. The PDS was tested with a good correlation between capacitance and RF frequencies. The robust PDS design enables a stable discharge of plasma with a low deviation of RF signals during the total 15 hours’ test.
K-means-driven Gaussian Process data collection for angle-resolved photoemission spectroscopy
Authors: Melton Charles N , Noack Marcus M , Ohta Taisuke , Beechem Thomas E , Robinson Jeremy , Zhang Xiaotian , Bostwick Aaron , Jozwiak Chris , Koch Roland J , Zwart Petrus H , Hexemer Alexander , Rotenberg Eli
Published: July 2020

We propose the combination of k-means clustering with Gaussian Process (GP) regression in the analysis and exploration of 4D angle-resolved photoemission spectroscopy (ARPES) data. Using cluster labels as the driving metric on which the GP is trained, this method allows us to reconstruct the experimental phase diagram from as low as 12% of the original dataset size. In addition to the phase diagram, the GP is able to reconstruct spectra in energy-momentum space from this minimal set of data points. These findings suggest that this methodology can be used to improve the efficiency of ARPES data collection strategies for unknown samples. The practical feasibility of implementing this technology at a synchrotron beamline and the overall efficiency implications of this method are discussed with a view on enabling the collection of more samples or rapid identification of regions of interest.
Modeled Air Pollution from In Situ Burning and Flaring of Oil and Gas Released Following the Deepwater Horizon Disaster
Authors: Pratt Gregory C , Stenzel Mark R , Kwok Richard K , Groth Caroline P , Banerjee Sudipto , Arnold Susan F , Engel Lawrence S , Sandler Dale P , Stewart Patricia A
Published: July 2020

The GuLF STUDY, initiated by the National Institute of Environmental Health Sciences, is investigating the health effects among workers involved in the oil spill response and clean-up (OSRC) after the Deepwater Horizon (DWH) explosion in April 2010 in the Gulf of Mexico. Clean-up included in situ burning of oil on the water surface and flaring of gas and oil captured near the seabed and brought to the surface. We estimated emissions of PM2.5 and related pollutants resulting from these activities, as well as from engines of vessels working on the OSRC. PM2.5 emissions ranged from 30 to 1.33e6 kg per day and were generally uniform over time for the flares but highly episodic for the in situ burns. Hourly emissions from each source on every burn/flare day were used as inputs to the AERMOD model to develop average and maximum concentrations for 1-, 12-, and 24-h time periods. The highest predicted 24-h average concentrations sometimes exceeded 5000 µg m−3 in the first 500 m downwind of flaring and reached 71 µg m−3 within a kilometer of some in situ burns. Beyond 40 km from the DWH site, plumes appeared to be well mixed, and the predicted 24-h average concentrations from the flares and in situ burns were similar, usually below 10 µg m−3. Structured averaging of model output gave potential PM2.5 exposure estimates for OSRC workers located in various areas across the Gulf. Workers located nearest the wellhead (hot zone/source workers) were estimated to have a potential maximum 12-h exposure of 97 µg m−3 over the 2-month flaring period. The potential maximum 12-h exposure for workers who participated in in situ burns was estimated at 10 µg m−3 over the ~3-month burn period. The results suggest that burning of oil and gas during the DWH clean-up may have resulted in PM2.5 concentrations substantially above the U.S. National Ambient Air Quality Standard for PM2.5 (24-h average = 35 µg m−3). These results are being used to investigate possible adverse health effects in the GuLF STUDY epidemiologic analysis of PM2.5 exposures.
Coronavirus Disease 2019 Outbreak in a San Francisco Homeless Shelter
Authors: Imbert Elizabeth , Kinley Patrick M , Scarborough Ashley , Cawley Caroline , Sankaran Madeline , Cox Sarah N , Kushel Margot , Stoltey Juliet , Cohen Stephanie , Fuchs Jonathan D
Published: July 2020

We report the public health response to a coronavirus disease 2019 (COVID-19) outbreak in a San Francisco shelter where 67% of residents and 17% of staff tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We describe the limited utility of case investigation, person-based contact tracing and symptom screening, and the benefits of mass testing in outbreak response.
Type 2 Myocardial Infarction: Evolving Approaches to Diagnosis and Risk-Stratification
Authors: Chapman Andrew R , Sandoval Yader
Published: July 2020

Background

Type 2 myocardial infarction (T2MI) is frequently encountered in clinical practice and associated with adverse outcomes.

Content

T2MI occurs most frequently due to noncoronary etiologies that alter myocardial oxygen supply and/or demand. The diagnosis of T2MI is often confused with acute nonischemic myocardial injury, in part because of difficulties in delineating the nature of symptoms and misunderstandings about disease categorization. The use of objective features of myocardial ischemia using electrocardiographic (ECG) or imaging abnormalities may facilitate more precise T2MI diagnosis. High-sensitivity cardiac troponin (hs-cTn) assays allow rapid MI diagnosis and risk stratification, yet neither maximum nor delta values facilitate differentiation of T2MI from T1MI. Several investigational biomarkers have been evaluated for T2MI, but none have robust data. There is interest in evaluating risk profiles among patients with T2MI. Clinically, the magnitude of maximum and delta cTn values as well as the presence and magnitude of ischemia on ECG or imaging is used to indicate disease severity. Scoring systems such as GRACE, TIMI, and TARRACO have been evaluated, but all have limited to modest performance, with substantial variation in time intervals used for risk-assessment and endpoints used.

The diagnosis of T2MI requires biomarker evidence of acute myocardial injury and clear clinical evidence of acute myocardial ischemia without atherothrombosis. T2MIs are most often caused by noncoronary etiologies that alter myocardial oxygen supply and/or demand. They are increasingly encountered in clinical practice and associated with poor short- and long-term outcomes. Clinicians require novel biomarker or imaging approaches to facilitate diagnosis and risk-stratification.
Medea is a Good Boy: performing, subverting, and unmasking tragic gender
Authors: Baldwin Oliver
Published: July 2020

In 1981, the Spanish playwright Luis Riaza published the play Medea es un buen chico (Medea is a Good Boy). In it, two male actors perform the main roles of Medea and the Nurse, who comment, with references to other fictional love stories, on the relationship between Medea and Jason. When Jason fails to arrive, the fiction is dismantled, revealing Medea’s identity as Jason’s rejected homosexual lover. Medea es un buen chico mixes elements of performativity, meta-theatricality, and myth in order to explore the limits of gender, sexuality, and the perceived social roles and norms they entail. This article explores how Riaza theatrically reflects on the social performativity of gender through the tragic character and story of Medea, her performance and subversion of her own gendered self, and her eventual rejection and social displacement.
Patient-reported outcomes and medication adherence in patients with heart failure
Authors: Rasmussen Anne Ankerstjerne , Wiggers Henrik , Jensen Martin , Berg Selina Kikkenborg , Rasmussen Trine Bernholdt , Borregaard Britt , Thrysoee Lars , Thorup Charlotte Brun , Mols Rikke Elmose , Larsen Signe Holm , Johnsen Søren Paaske
Published: July 2020

Aims

Patient-reported outcome measures (PROMs) may predict poor clinical outcome in patients with heart failure (HF). It remains unclear whether PROMs are associated with subsequent adherence to HF medication. We aimed to determine whether health-related quality of life, anxiety, and depression were associated with long-term medication adherence in these patients.

Methods and results

A national cohort study of Danish patients with HF with 3-year follow-up (n = 1464). PROMs included the EuroQol five-dimensional, five-level questionnaire (EQ-5D-5L), the HeartQoL and the Hospital Anxiety and Depression Scale (HADS). Patient-reported outcomes (PRO) data were linked to demographic and clinical data at baseline, and data on all redeemed prescriptions for angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers/angiotensin receptor neprilysin inhibitors (ACEI/ARB/ARNI), β-blockers, and mineralocorticoid receptor antagonists during follow-up. Medication non-adherence was defined as <80% of proportion of days covered. In adjusted regression analyses, lower health-related quality of life (EQ-5D and HeartQoL) and symptoms of depression (HADS-D) at discharge were associated with non-adherence. After 3 years of follow-up, lower health-related quality of life (EQ-5D) was associated with non-adherence for ACEI/ARB/ARNI [adjusted OR 2.78, 95% confidence interval (CI): 1.19–6.49], β-blockers (adjusted OR 2.35, 95% CI: 1.04–5.29), whereas HADS-D was associated with non-adherence for ACEI/ARB/ARNI (adjusted OR 1.07, 95% CI: 1.03–1.11) and β-blockers (adjusted OR 1.06, 95% CI: 1.02–1.10).

Conclusion

Lower health-related quality of life and symptoms of depression were associated with non-adherence across HF medications at 1 and 3 years of follow-up. Person-centred care using PROMs may carry a potential for identifying patients at increased risk of future medication non-adherence.
Examining vaccination coverage in Germany: spatiotemporal clustering of MMR coverage, 2008–14
Authors: Spencer Cory N , Delamater Paul L
Published: July 2020

Vaccine hesitancy is an increasing global health threat but much of the recent research has centred on the USA. European countries provide an interesting context due to increases in vaccine-preventable disease outbreaks as well as variability in vaccination laws. We investigated the spatiotemporal clustering of Measles, Mumps, and Rubella vaccination coverage in Germany, a country with a historic absence of compulsory vaccination laws. We also examined measles incidence in the context of the spatiotemporal clustering results. While we did not identify strong spatial patterns of geographic clustering in Germany, our results suggest a potential relationship between measles incidence and vaccination coverage cluster status.
Chlamydia suisis associated with intestinal NF-κB activation in experimentally infected gnotobiotic piglets
Authors: Aumayer Helen , Leonard Cory Ann , Pesch Theresa , Prähauser Barbara , Wunderlin Sabina , Guscetti Franco , Borel Nicole
Published: July 2020

Chlamydia suis intestinal infection of single-animal experimental groups of gnotobiotic newborn piglets was previously reported to cause severe, temporary small intestinal epithelium damage. We investigated archived intestinal samples for pro-inflammatory nuclear factor kappa B (NF-κB) activation, Interleukin (IL)-6 and IL-8 production and immune cell influx. Samples were collected 2, 4 and 7 days post-inoculation with C. suis strain S45/6 or mock inoculum (control). Increased nuclear localization of epithelial NF-κB, representative of activation, in the jejunum and ileum of C. suis-infected animals, compared to uninfected controls, began by 2 days post-infection (dpi) and persisted through 7 dpi. Infected animals showed increased production of IL-8, peaking at 2 dpi, compared to controls. Infection-mediated CD45-positive immune cell influx into the jejunal lamina propria peaked at 7 dpi, when epithelial damage was largely resolved. Activation of NF-κB appears to be a key early event in the innate response of the unprimed porcine immune system challenged with C. suis. This results in an acute phase, coinciding with the most severe clinical symptoms, diarrhea and weight loss. Immune cells recruited shortly after infection remain present in the lamina propria during the recovery phase, which is characterized by reduced chlamydial shedding and restored intestinal epithelium integrity.
DOCK3 is a dosage-sensitive regulator of skeletal muscle and Duchenne muscular dystrophy-associated pathologies
Authors: Reid Andrea L , Wang Yimin , Samani Adrienne , Hightower Rylie M , Lopez Michael A , Gilbert Shawn R , Ianov Lara , Crossman David K , Dell’Italia Louis J , Millay Douglas P , van Groen Thomas , Halade Ganesh V , Alexander Matthew S
Published: July 2020

DOCK3 is a member of the DOCK family of guanine nucleotide exchange factors that regulate cell migration, fusion and viability. Previously, we identified a dysregulated miR-486/DOCK3 signaling cascade in dystrophin-deficient muscle, which resulted in the overexpression of DOCK3; however, little is known about the role of DOCK3 in muscle. Here, we characterize the functional role of DOCK3 in normal and dystrophic skeletal muscle. Utilizing Dock3 global knockout (Dock3 KO) mice, we found that the haploinsufficiency of Dock3 in Duchenne muscular dystrophy mice improved dystrophic muscle pathologies; however, complete loss of Dock3 worsened muscle function. Adult Dock3 KO mice have impaired muscle function and Dock3 KO myoblasts are defective for myogenic differentiation. Transcriptomic analyses of Dock3 KO muscles reveal a decrease in myogenic factors and pathways involved in muscle differentiation. These studies identify DOCK3 as a novel modulator of muscle health and may yield therapeutic targets for treating dystrophic muscle symptoms.
Advancements towards selective barrier passage by automatic species identification: applications of deep convolutional neural networks on images of dewatered fish
Authors: Eickholt Jesse , Kelly Dylan , Bryan Janine , Miehls Scott , Zielinski Dan
Published: July 2020

Invasive species negatively affect enterprises such as fisheries, agriculture, and international trade. In the Laurentian Great Lakes Basin, threats include invasive sea lamprey (Petromyzon marinus) and the four major Chinese carps. Barriers have proven to be an effective mechanism for managing invasive species but are detrimental in that they also limit the migration of desirable, native species. Fish passage technologies that selectively pass desirable species while blocking undesirable species are needed. Key to an automated selective barrier passage system is a high precision fish classifier to assign fish to be passed or blocked. Presented is an evaluation of two classifiers developed using images of partially dewatered fish captured from a commercial, high-speed camera array. For a lamprey vs. non-lamprey classification task, an ensemble prediction approach achieved near perfect accuracy on both a validation and test dataset. For a species classification task for 13 species found in the Great Lakes region, an ensemble prediction approach achieved accuracies of 96% and 97% on a validation and test dataset, respectively. Both prediction approaches were based on deep convolutional neural networks constructed using transfer learning and image augmentation. The study provides an important proof-of-concept for the viability in fully automated, selective fish passage systems.
Delayed surgery after mechanical circulatory support for ventricular septal rupture with cardiogenic shock
Authors: Morimura Hayato , Tabata Minoru
Published: July 2020

OBJECTIVES

The effectiveness of delayed surgery for ventricular septal rupture (VSR) following myocardial infarction (MI) in patients with cardiogenic shock remains unknown. We aimed to investigate the outcomes of delayed surgery following mechanical circulatory support for patients in cardiogenic shock after VSR.

METHODS

We reviewed 8 patients with post-MI VSR and cardiogenic shock who underwent delayed surgery at our institution between July 2015 and November 2017. Surgery was delayed until haemodynamic stabilization and improved organ ischaemia were achieved by initiating intra-aortic balloon pumping with or without veno-arterial extracorporeal membrane oxygenation (ECMO). We investigated the operative mortality, morbidity and late survival.

RESULTS

All 8 patients had preoperative intra-aortic balloon pump support, and 5 had additional veno-arterial ECMO support. Emergency repair was successfully avoided in all cases. The median time from the onset of MI to operation was 7.1 (3.7–9.9) days, and that from the diagnosis of VSR to operation was 1.9 (1.3–2.3) days. The operative mortality was 12.5%, and complications related to mechanical circulatory support occurred in 1 case (12.5%). The 2-year survival rate was 62.5%.

CONCLUSIONS

A combination of preoperative mechanical circulatory support and delayed surgery may improve the outcomes of patients with post-MI VSR, which was complicated by cardiogenic shock. The key to a better surgical outcome may be delaying the surgery for improving end-organ perfusion. This requires further investigation, especially for determining the optimal duration of support.
Plant foods, dietary fibre and risk of ischaemic heart disease in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort
Authors: Perez-Cornago Aurora , Crowe Francesca L , Appleby Paul N , Bradbury Kathryn E , Wood Angela M , Jakobsen Marianne Uhre , Johnson Laura , Sacerdote Carlotta , Steur Marinka , Weiderpass Elisabete , Würtz Anne Mette L , Kühn Tilman , Katzke Verena , Trichopoulou Antonia , Karakatsani Anna , La Vecchia Carlo , Masala Giovanna , Tumino Rosario , Panico Salvatore , Sluijs Ivonne , Skeie Guri , Imaz Liher , Petrova Dafina , Quirós J Ramón , Yohar Sandra Milena Colorado , Jakszyn Paula , Melander Olle , Sonestedt Emily , Andersson Jonas , Wennberg Maria , Aune Dagfinn , Riboli Elio , Schulze Matthias B , di Angelantonio Emanuele , Wareham Nicholas J , Danesh John , Forouhi Nita G , Butterworth Adam S , Key Timothy J
Published: July 2020

Background

Epidemiological evidence indicates that diets rich in plant foods are associated with a lower risk of ischaemic heart disease (IHD), but there is sparse information on fruit and vegetable subtypes and sources of dietary fibre. This study examined the associations of major plant foods, their subtypes and dietary fibre with risk of IHD in the European Prospective Investigation into Cancer and Nutrition (EPIC).

Methods

We conducted a prospective analysis of 490 311 men and women without a history of myocardial infarction or stroke at recruitment (12.6 years of follow-up, n cases = 8504), in 10 European countries. Dietary intake was assessed using validated questionnaires, calibrated with 24-h recalls. Multivariable Cox regressions were used to estimate hazard ratios (HR) of IHD.

Results

There was a lower risk of IHD with a higher intake of fruit and vegetables combined [HR per 200 g/day higher intake 0.94, 95% confidence interval (CI): 0.90–0.99, P-trend = 0.009], and with total fruits (per 100 g/day 0.97, 0.95–1.00, P-trend = 0.021). There was no evidence for a reduced risk for fruit subtypes, except for bananas. Risk was lower with higher intakes of nuts and seeds (per 10 g/day 0.90, 0.82–0.98, P-trend = 0.020), total fibre (per 10 g/day 0.91, 0.85–0.98, P-trend = 0.015), fruit and vegetable fibre (per 4 g/day 0.95, 0.91–0.99, P-trend = 0.022) and fruit fibre (per 2 g/day 0.97, 0.95–1.00, P-trend = 0.045). No associations were observed between vegetables, vegetables subtypes, legumes, cereals and IHD risk.

Conclusions

In this large prospective study, we found some small inverse associations between plant foods and IHD risk, with fruit and vegetables combined being the most strongly inversely associated with risk. Whether these small associations are causal remains unclear.
Coronavirus Disease 2019 Epidemic Doubling Time in the United States Before and During Stay-at-Home Restrictions
Authors: Lurie Mark N , Silva Joe , Yorlets Rachel R , Tao Jun , Chan Philip A
Published: July 2020

Background

Coronavirus disease 2019 (COVID-19) has spread rapidly in the United States since January 2020.

Methods

We estimated mean epidemic doubling time, an important measure of epidemic growth, nationally, by state, and in association with stay-at-home orders.

Results

The epidemic doubling time in the United States was 2.68 days (95% confidence interval [CI], 2.30–3.24 days) before widespread mitigation efforts, increasing by 460% to 15 days (12.89–17.94 days) during the mitigation phase. Among states without stay-at-home orders, the median increase in doubling time was 60% (95% CI, 9.2–223.3), compared with 269% (95% CI, 277.0–394.0) for states with stay-at-home orders.

Conclusions

Statewide mitigation strategies were strongly associated with increased epidemic doubling time.