bluuebunny/crossref_metadata_2025 huggingface dataset:
Statistical analysis of vehicular accidents and alternatives for critical points
Authors: Rojas Suárez J P , Prada Botía G C , Orjuela Abril M S
Published: December 2020

There are different factors that can cause a vehicular accident, starting with the carelessness of the driver or pedestrian, putting in risk his life and the life of third parties; by roads in bad conditions and lack of signaling, without warning him of the adversities that continue in the road, for this reason, the research work was developed on the causes of road accidents in four sectors, compiling information on the roads corresponding to the proposed streets and avenues, followed by defining the possible causes of the problems in the critical sites and thus defining the potential factors of an accident. Finally, solutions are proposed to reduce the percentages of vehicle accidents at the critical points found, decreasing the indicators of accident and mortality in this vehicle sector, giving people peace of mind when leaving their homes.
Aeroelastic and sloshing stability of slender hypersonic vehicle
Authors: Qiao Haiyan , Yang Ya , Meng Hao , Ke Wei , Xu Jiangtao
Published: December 2020

This paper focuses on the problem of the coupling between the rigid body mode and elastic mode caused by the light structure design and slender geometry of the hypersonic vehicle, and the influence of the liquid sloshing on the aircraft. In order to analyze the complex dynamics of hypersonic vehicle, the nonlinear dynamic model of a flexible vehicle is established in the case of the vehicle’s elastic deformation. The yields terms that produce nonlinear coupling between the elastic deflections, liquid sloshing and the rigid-body motion parameters are obtained by Lagrangian approach. Then, the equations are reduced to a linear set for stability analysis. Finally, some numerical simulations are given that reveal a destabilizing influence of elastic deflections and liquid sloshing at stability for a particular vehicle configuration.
Experimental investigation of a five-spring vibration isolator
Authors: Liu Shuyong , Su Pan , Yang Lihua , Feng Xuejiao , Liu Haisong
Published: December 2020

In order to suppress low frequency vibration more effectively, a quasi-zero stiffness vibration isolation device is designed by using five parallel linear springs. The stiffness characteristic of the system is analyzed, and the quasi-zero stiffness (QZS) condition of the system is given. The dynamic behavior analysis of the system is analyzed by harmonic balance method, and the force transmissibility is obtained. The effects of damping ratio and excitation force on the system transfer rate are analyzed. In order to verify the vibration isolation performance of QZS vibration system, a series of experiments were carried out. The experimental results show that the low frequency vibration isolation performance of the QZS vibration system is much better than that of the corresponding linear system.
An investigation of soft impacts on selected aerospace grade alloys based on Johnson-Cook Material Model
Authors: Azeem Aslam Muhammad , Ke Zhang , Rayhan Saiaf Bin , Faizan Muhammad , Mamuda Bello Inuwa
Published: December 2020

In aerospace industry, metallic alloys are regularly used to manufacture various components ranging from stabilizers to engine shafts. These components must withstand foreign objective damage (FOD), which includes bird strikes, hail, ice, or any metal or concrete debris from the runway. In this current research, some selected aerospace grade alloys, namely, Al-2024-T3, Al-7075-T6, Ti-6Al-4V, and Inconel-718, which are regularly used to build potential aircraft components exposed to bird strike (otherwise known as soft impact) phenomena, is numerically tested to investigate their ability to resist the collision under two different impact velocities (117 m/s and 147 m/s). Finite element explicit code Ansys is adopted to run the test cases. Johnson-Cook flow stress and damage parameters are selected to model the alloy materials while Mooney-Rivlin parameters are utilized to represent the Lagrange bird model. From the investigation, it is found that the Inconel-718 plate is the best candidate to resist the bird impact and further analysis reveals that it can withstand an impact velocity of 327 m/s without being penetrated. Apart from Inconel-718 alloy, both Al-2024-T3 and Ti-6Al-4V plates are found to be damaged at the impact velocity of 147 m/s, while Al- 7075-T6 is completely penetrated even at a lower impact velocity, 117 m/s. Finally, some recommendations and future research directions are suggested based on numerical outcomes.
An epidemic model with the closed management in Chinese universities for COVID-19 prevention
Authors: Wang Chaoqian , Huang Chaochao
Published: December 2020

COVID-19 has deeply changed people’s way of life. While the anti-epidemic work in Chine has been successful, many Chinese universities still prohibit students from leaving the campus. In the meanwhile, faculty and staff can be on or off campus at will. This paper establishes an SI model to describe such a phenomenon. It is assumed that the latent population in society is a tiny constant, to which only a fraction of university population is exposed. Due to the closed management, a single individual cannot be exposed to the university and social population at the same time. A set of differential equations are proposed, and the standard solution is found. The results show that the entire closeness makes the virus not transmit in the university, and partial closeness leads the virus to spread on campus. By numerical simulation, the latent proportion as a function of different off-campus-allowed proportions is presented. It is found that to minimize the latent proportion, as many individuals should be allowed to be off-campus as possible when they are less likely to leave the campus, and there exists optimum allowed proportion when they are more likely to leave the campus. Furthermore, based on theoretical analysis, a quantitative formula describing the optimum allowed proportion in the general situations is given, providing the university administration with a method to calculate the optimum policy.
Research on women’s career choice based on MADM with IFS
Authors: Lv Zhiying , Gong Jixing
Published: December 2020

Role positioning of women is an important research topic, which seriously affects women’s life path. This paper constructs three-way decision models based on intuitive multi-attribute decision making method (MADM) to help women choose roles. First, by analysing the factors that affect the role positioning of modern women, the decision-making evaluation system is constructed. Second, decision attribute values for every female are given by intuitionistic fuzzy sets (IFS). Third, the conditional possibilities of becoming a professional female is computed combined with the attribute weights. Finally, each female’s role is defined by comparing conditional probabilities and decision initial values computed by loss functions.
Various formulations of inequivalent Leggett–Garg inequalities
Authors: Kumari Swati , Pan A K
Published: December 2020

In two-party, two-input and two-output measurement scenario only relevant Bell’s inequality is the Clauser–Horne–Shimony–Holt (CHSH) form. They also provide the necessary and sufficient conditions (NSCs) for local realism. Any other form, such as, Clauser–Horne and Wigner forms reduce to the CHSH one. The standard Leggett–Garg inequalities, proposed for testing incompatibility between macrorealism and quantum theory, are often considered to be the temporal analog of CHSH inequalities. However, they do not provide the NSCs for macrorealism. There is thus scope of formulating new macrorealist inequalities inequivalent and stronger than the standard Leggett–Garg inequalities. In this paper, we propose two different classes of macrorealistic inequalities. A class of inequalities which are equivalent to the standard ones in macrorealist model but inequivalent and stronger in quantum theory, and the other class of inequalities are inequivalent to the all the other formulations of Leggett–Garg inequalities both in macrorealist model and in quantum theory. The latter class of macrorealist inequalities reveals the incompatibility between macrorealism and quantum theory for specific cases even when any other formulation of Leggett–Garg inequalities fails to do so. We extend the formulations of inequivalent Leggett–Garg inequalities to the four-time and two-time measurement scenarios. Further, we provide a brief discussion about the alternative formulation of macrorealism known as the no-signaling in time (NSIT) conditions.
Providing pharmacy services in a basketball arena: Reflections on building a pharmacy in a COVID-19 surge facility
Authors: Warr Dillon , Storey Eileen , Denys Mark , Brown Suzanne , Rose Christina
Published: December 2020

Purpose

As Coronavirus disease 19 (COVID-19) has spread globally, hospital systems have seen an increasing strain on their ability to accommodate the growing caseload. This demand has led countries to adopt varying surge-facility or alternate care site (ACS) models to manage patient overflow. This report describes the experience of setting up pharmacy services at a city-run surge facility in Philadelphia.

The COVID-19 Surge Facility at the Liacouras Center (CSF-L) was initially developed to serve as a site for patients convalescing from acute inpatient stays in order to free up healthcare resources in surrounding hospitals. The CSF-L site required a distinct set of services to provide the desired level of care. This report details the preparations and challenges faced by the CSF-L pharmacy team in this endeavor, including identifying a pharmacy location that met regulatory requirements, obtaining proper licenses, coordinating drug procurement, filling staffing requirements, developing a formulary, defining the pharmacy and medication management workflow, and ensuring safety protocols were followed. This report explains the rational for developing certain processes and suggests alternative options and ideal plans for developing future pharmacy services in an ACS.

Conclusion

Identifying a pharmacy leadership team early in the ACS planning process can lead to more efficient plans for pharmacy services. This report details the important steps taken, decisions made, and challenges faced in setting up pharmaceutical services at a COVID-19 field hospital.
The permissible scope of witness testimony in arbitral hearings—five proposed rules
Authors: Risse Jörg , Baumann Antje
Published: December 2020

At least one surprise occurs in every arbitral hearing. One of those surprises is when a witness testifies beyond what has been submitted in his written witness statement. Often, such ‘out-of-scope’ testimony is unexpected, astonishing, and crucial for the outcome of the case. Surprisingly, the adequate handling of such unexpected testimony is unchartered territory: neither arbitral statutes, institutional rules nor the ever-expanding arbitral soft law addresses this important issue. This article reviews if and when arbitral tribunal should permit or reject such ‘out-of-scope’ testimony. The article establishes five clear-cut rules to deal with that issue.
The cost-effectiveness of one-time opportunistic screening for atrial fibrillation in different age cohorts of inhabitants in Denmark aged 65 years and above: a Markov modelled analysis
Authors: Sciera Lucca Katrine , Frost Lars , Dybro Lars , Poulsen Peter Bo
Published: December 2020

Aims

The objective was to evaluate the cost-effectiveness of one-time opportunistic screening for atrial fibrillation (AF) in general practice in citizens aged ≥65 years in Denmark compared to a no-screening alternative following current Danish practice.

Methods and results

A decision tree and a Markov model were designed to simulate costs and quality-adjusted life years (QALYs) in a hypothetical cohort of citizens aged ≥65 years equivalent to the Danish population (1 M citizens) over the course of 19 years, using a healthcare and societal perspective. Share of detected AF patients following opportunistic screening was retrieved from a recent Danish screening study, whereas the risk stroke and bleedings in AF patients were based on population data from national registries and their associated costs was obtained from published national registry studies. The present study showed that one-time opportunistic screening for AF was more costly, but also more effective compared to a no-screening alternative. The analysis predicts that one-time opportunistic screening of all Danes aged ≥65 years potentially can identify an additional 10 300 AF patients and prevent 856 strokes in the period considered. The incremental cost of such a screening programme is €56.4 M, with a total gain of 6000 QALYs, resulting in an incremental cost-effectiveness ratio of €9400 per QALY gained.

Conclusion

Opportunistic screening in general practice in citizens aged ≥65 years in Denmark is cost-effective compared to a willingness-to-pay threshold of €22 000. The study and its findings support a potential implementation of opportunistic screening for AF at the general practitioner level in Denmark.
Atlas-based methods for efficient characterization of patient-specific ventricular activation patterns
Authors: Vincent Kevin P , Forsch Nickolas , Govil Sachin , Joblon Jake M , Omens Jeffrey H , Perry James C , McCulloch Andrew D
Published: December 2020

Aims

Ventricular activation patterns can aid clinical decision-making directly by providing spatial information on cardiac electrical activation or indirectly through derived clinical indices. The aim of this work was to derive an atlas of the major modes of variation of ventricular activation from model-predicted 3D bi-ventricular activation time distributions and to relate these modes to corresponding vectorcardiograms (VCGs). We investigated how the resulting dimensionality reduction can improve and accelerate the estimation of activation patterns from surface electrogram measurements.

Methods and results

Atlases of activation time (AT) and VCGs were derived using principal component analysis on a dataset of simulated electrophysiology simulations computed on eight patient-specific bi-ventricular geometries. The atlases provided significant dimensionality reduction, and the modes of variation in the two atlases described similar features. Utility of the atlases was assessed by resolving clinical waveforms against them and the VCG atlas was able to accurately reconstruct the patient VCGs with fewer than 10 modes. A sensitivity analysis between the two atlases was performed by calculating a compact Jacobian. Finally, VCGs generated by varying AT atlas modes were compared with clinical VCGs to estimate patient-specific activation maps, and the resulting errors between the clinical and atlas-based VCGs were less than those from more computationally expensive method.

Conclusion

Atlases of activation and VCGs represent a new method of identifying and relating the features of these high-dimensional signals that capture the major sources of variation between patients and may aid in identifying novel clinical indices of arrhythmia risk or therapeutic outcome.
Comparative analysis of Methicillin-Resistant Staphylococcus aureus (MRSA) and Borderline Oxacillin Resistant Staphylococcus aureus (BORSA) in community and food of animal origin
Authors: Zehra Asima , Gulzar Maliha , Singh Randhir , Kaur Simranpreet , Gill J P S
Published: December 2020

The aim of this study was to illustrate the relative pervasiveness of Borderline Oxacillin Resistant Staphylococcus aureus (BORSA) and Methicillin-Resistant Staphylococcus aureus (MRSA) in community and food of animal origin and their relationship with other genetic determinants. Staphylococcus aureus isolates were subjected to E-test using the antibiotics: oxacillin, ceftriaxone, cotrimoxazole, vancomycin, genotypic tests for the genes mecA, vanA, blaZ, pvl gene and SCCmec typing. The prevalence of S. aureus (MRSA) in the food of animal origin and community settings was 21% (1.8% MRSA) and 21.9% (7.4% MRSA), respectively. SCCmec type V was prevalent among the food of animal origin, while SCCmec type IVa among the community isolates. The likelihood of MRSA presence among community isolates was three times more than in isolates from chicken and milk samples. Likewise, the likelihood of detecting pvl positive MRSA (pvl+MRSA) isolates was 4-fold higher in the community setting than in the food of animal origin. The mecA negative BORSA (mecA−BORSA) was a frequently observed phenotype among S. aureus isolates. Also, co-detection of pvl and cotrimoxazol resistance was reported in this study although there was no noteworthy correlation of cotrimoxazol resistance with the type of sample. Isolates from milk and community settings exhibit higher minimum inhibitory concentration to vancomycin (Vancomycin MIC creep, 2–4 µg/mL).

Significance

Current study provides the information on the statistical relationship between the genetic determinants of S. aureus with respect to sample type, and additionally the correlation that exists between the pvl and MRSA, pvl and cotrimoxazol resistance, vancomycin MIC and MRSA/Methicillin-Susceptible S. aureus (MSSA).
On negative induced polarization in frequency domain measurements
Authors: Wang Chen , Binley Andrew , Slater Lee D
Published: December 2020

Induced polarization (IP) has been widely used to non-invasively characterize electrical conduction and polarization in the subsurface resulting from an applied electric field. Earth materials exhibit a lossy capacitance defined by a negative intrinsic phase in frequency-domain IP (FDIP) or a positive intrinsic chargeability in time-domain IP (TDIP). However, error-free positive apparent phase or negative apparent chargeability (i.e. negative IP effects) can occur in IP measurements over heterogeneous media. While negative IP effects in TDIP data sets have been discussed, no studies have addressed this topic in detail for FDIP measurements. We describe theory and numerical modelling to explain the origin of negative IP effects in FDIP measurements. A positive apparent phase may occur when a relatively high polarizability feature falls into negative sensitivity zones of complex resistivity measurements. The polarity of the apparent phase is determined by the distribution of subsurface intrinsic phase and resistivity, with the resistivity impacting the apparent phase polarity via its control on the sensitivity distribution. A physical explanation for the occurrence of positive apparent phase data is provided by an electric circuit model representing a four-electrode measurement. We also show that the apparent phase polarity will be frequency dependent when resistivity changes significantly with frequency (i.e. in the presence of significant IP effects). Consequently, negative IP effects manifest themselves in the shape of apparent phase spectra recorded with multifrequency (spectral IP) data sets. Our results imply that positive apparent phase measurements should be anticipated and should be retained during inversion and interpretation of single frequency and spectral IP data sets.
Risk Factors for Poor Outcome or Death in Young Children With Respiratory Syncytial Virus–Associated Acute Lower Respiratory Tract Infection: A Systematic Review and Meta-Analysis
Authors: Shi Ting , Vennard Sophie , Mahdy Sara , Nair Harish ,   RESCEU investigators, Nair Harish , Campbell Harry , Shi Ting , Li You , Openshaw Peter , Beutels Philippe , Bont Louis , Pollard Andrew , Molero Eva , Martinon-Torres Federico , Heikkinen Terho , Meijer Adam , Fischer Thea Kølsen , van den Berge Maarten , Giaquinto Carlo , Abram Michael , Swanson Kena , Stoszek Sonia K , Gallichan Scott , Demont Clarisse , Aerssens Jeroen , Cheret Arnaud , Rosen Brian , Fuentes Robert
Published: December 2020

Background

Respiratory syncytial virus (RSV)–associated acute lower respiratory tract infection (RSV-ALRTI) constitutes a substantial disease burden in young children. We aimed to identify all studies investigating the risk factors for RSV-ALRTI poor outcome or death in young children.

Methods

We carried out a systematic literature review across 7 databases with data from studies published from January 1995 to December 2019. We defined poor outcome as need for prolonged hospital stay, oxygen supplementation, mechanical ventilation, or intensive care unit admission. The quality of all eligible studies was assessed according to modified Grading of Recommendations, Assessment, Development and Evaluations (GRADE) criteria. We conducted meta–analyses to estimate odds ratios (ORs) with 95% confidence intervals (CIs) for individual risk factors.

Results

We identified 27 eligible studies, which investigated 20 risk factors for RSV-ALRTI poor outcome and/or death in children <5 years old, compared with children with RSV-ALRTI who did not have poor outcome or who did not die. Among the risk factors, 6 were significantly associated with RSV-ALRTI poor outcome: any comorbid condition (OR, 2.69; 95% CI, 1.89–3.83), congenital heart disease (3.40; 2.14–5.40), prematurity with gestational age (GA) <37 weeks (1.75 (1.31–2.36), prematurity with GA ≤32 weeks (2.68; 1.43–5.04), age <3 months (4.91; 1.64–14.71), and age <6 months (2.02; 1.73–2.35). The meta-estimate ORs for all risk factors other than age <3 months were based on studies using multivariable analysis. For death, only prematurity with GA <37 weeks had a significant meta-estimated OR—3.81 (95% CI, 1.68–8.63)—based on univariable analysis.

Conclusions

This study represents a comprehensive report of the association between various risk factors and RSV-ALRTI poor outcome or death in young children. More research should be carried out to elucidate risk factors associated with poor outcome or death using multivariable analysis.
Analysis of Diglycolic Acid after Mass Poisoning by Diethylene Glycol
Authors: Goulart Cristiano O L , Bordoni Leonardo S , Nascentes Clésia C , Costa Letícia M
Published: December 2020

In December 2019, unusual cases of acute renal failure with neurological changes were observed in the State of Minas Gerais, Brazil. Criminal investigations indicated cases of intoxication after consumption of beers contaminated with diethylene glycol (DEG). The elimination of DEG by the body is fast, but its metabolite, diglycolic acid (DA), may persist for a long time. To assess the level of intoxicated victims who consumed the contaminated beers, qualitative and quantitative methods were developed to determine DA in biological matrices by gas chromatography coupled to a mass spectrometer (GC–MS) and gas chromatography coupled to a mass spectrometer with triple-quadrupole mass filter (GC–MS-MS), respectively. The validated qualitative method presents good selectivity and limit of detection of 1 µg/mL (whole blood, urine, vitreous humor and cerebrospinal fluid) and 5 µg/g (liver and kidney), respectively. A quantitative method for whole blood presented satisfactory performance to determine DA. Twelve victims presented positive results for DA in whole blood, with concentrations ranging from 2 to 108 µg/mL. The toxicology laboratory of the Institute of Forensic Medicine of Minas Gerais was the first governmental agency to identify DA in whole blood, vitreous humor, cerebrospinal fluid, kidney and urine in victims affected by this contaminant. The results of this study legally supported the prohibition of the continued consumption of the beer and avoided further intoxications. Our results showed, for real cases of human intoxication, that DA can still be detected in alternative matrices, even when non-detectable in blood, demonstrating the importance of collecting different kinds of samples for a proper investigation.
The systematics of the amphidromous shrimpMacrobrachium americanumSpence Bate, 1868 (Decapoda: Caridea: Palaemonidae) from the Mexican Pacific slope
Authors: García-Velazco Humberto , Maeda-Martínez Alejandro M , Obregón-Barboza Hortencia , Ruiz-Campos Gorgonio , Rodríguez-Almaraz Gabino A , Murugan Gopal
Published: December 2020

The amphidromous species of Macrobrachium Spence Bate, 1868 occurring on the Mexican Pacific slope (M. americanum Spence Bate, 1868, M. digueti (Bouvier, 1895), M. hobbsi Nates & Villalobos in Villalobos Hiriart & Nates Rodríguez, 1990, M. occidentale Holthuis, 1950 (Holthuis, 1950b), and M. tenellum (Smith, 1871)) show a disjunct distribution, with the abscence of records along about 2000 km of the coastal margins in the northern Gulf of California. Recent morphological and genetic studies using the mitochondrial genes 16S rRNA (16S) and cytochrome oxidase I (COI) show that individuals of the putative M. digueti, M. hobbsi, and M. occidentale from the Baja California Peninsula are conspecific to their respective taxonomic entities found along the Pacific slope of mainland Mexico. We review the systematics of M. americanum from the Mexican Pacific slope and found that individuals of putative M. americanum from the Baja California Peninsula belong to the same lineage of individuals from the Pacific slope of mainland Mexico based on newly generated fragments of the mitochondrial genes 16S (491 bp) and COI (548 bp). We present a systematic account for M. americanum, including a taxonomic treatment of the studied populations with a report of their genetic identity and phylogenetic relationships.
Creep hardening damage constitutive model of coal with fracture proppant
Authors: Cheng Qingying , Li Haoze , Huang Bingxiang , Zhao Xinglong
Published: December 2020

Fracture is the flow channel of gas (fluid) body in the exploitation of coalbed methane and other energy sources. It has a great influence on gas (fluid) production and work efficiency. Creep results in the proppant embedded in the coal seam leading to fracture damage, reducing fracture permeability. However, there are few studies on a creep model considering proppant embedding in fractures. In this paper, a creep test of proppant embedment in a fracture of a coal seam is carried out, and a creep model considering the damage to proppant embedment is established. The results show that with an increase of closure stress, the range of strain rate first increases and then decreases, and the mean value of strain rate increases slowly and then increases rapidly when the closure stress levels increases in the stable creep stage. During the creep of coal with a fracture proppant, there is not only the hardening and damage of coal, but there is also the damage to proppant embedding. A creep hardening damage model considering the viscosity damage factor of coal, the stress hardening model, the elastic-plastic damage factor, proppant compaction and the embedded viscosity loss factor is established. The creep hardening damage model can better describe the whole process of decelerating creep, stable creep and accelerating creep of coal with proppant fracture.
The collection of Fabio Fani: Carracci, Luti, Garzi, sharks’ teeth and the ‘nail of the Great Beast’
Authors: Serafinelli Guendalina
Published: December 2020

This article examines the collection of the neglected nobleman Fabio Fani, based on the evidence of his inventory drawn up in 1730. Housed in his Roman palace facing Piazza Borghese, Fabio’s collection consisted of more than 400 paintings, including works by notable artists. Prominent among them were two unusually monumental cycles by Benedetto Luti and Luigi Garzi, which now can be reconstructed and partly identified with paintings in public and private collections. In Fani’s palace there was also a cabinet of curiosities featuring naturalia, artificialia and objects from distant lands, as well as two rooms in which books on a variety of subjects were kept. A study of the display of art in Fabio’s residence and its dialogue with the space of the palace, the objects in the cabinet and the books furthers our understanding of collecting and display in early modern Rome.
TheCulexMosquitoes (Diptera: Culicidae) of French Guiana: A Comprehensive Review With the Description of Three New Species
Authors: Talaga Stanislas , Duchemin Jean-Bernard , Girod Romain , Dusfour Isabelle
Published: December 2020

The taxonomically intricate genus Culex Linnaeus includes numerous known vector species of parasites and viruses to humans. The aim of this article is to comprehensively review the Culex species which occur in French Guiana to provide a stronger taxonomic foundation for future studies on this genus in South America. The occurrence of Culex species was investigated in light of current taxonomic knowledge through an extensive examination of voucher specimens deposited in the entomological collections of four French depositories and additional specimens recently collected at various localities in French Guiana. Based on this review, 104 Culex species classified in eight subgenera are confirmed to occur in French Guiana. Compared to the most recent checklist, 18 species are added, and 10 species excluded, resulting in a total number of 242 valid mosquito species known to occur in French Guiana. Three nominal species are synonymized, three others are newly described, and a last one is transferred to another informal infrasubgeneric group. Overall, this review also highlights the limits of the use of only bibliographic data when dealing with taxonomically complex groups of insects.
Tracking computability of GPAC-generable functions
Authors: Poças Diogo , Zucker Jeffery
Published: December 2020

Analog computation attempts to capture any type of computation, that can be realized by any type of physical system or physical process, including but not limited to computation over continuous measurable quantities. A pioneering model is the General Purpose Analog Computer (GPAC), initially presented by Shannon in 1941. The GPAC is capable of manipulating real-valued data streams; however, it has been shown to be strictly less powerful than other models of computation on the reals, such as computable analysis.

In previous work, we proposed an extension of the Shannon GPAC, denoted LGPAC, designed to overcome its limitations. Not only is the LGPAC model capable of expressing computation over general data spaces $\mathcal{X}$, but it also directly incorporates approximating computations by means of a limit module. An important feature of this work is the generalisation of the framework of the computation theory from Banach to Fréchet spaces.

In this paper, we compare the LGPAC with a digital model of computation based on effective representations (tracking computability). We establish general conditions under which LGPAC-generable functions are tracking computable.
Baryon acoustic oscillations reconstruction using convolutional neural networks
Authors: Mao Tian-Xiang , Wang Jie , Li Baojiu , Cai Yan-Chuan , Falck Bridget , Neyrinck Mark , Szalay Alex
Published: December 2020

We propose a new scheme to reconstruct the baryon acoustic oscillations (BAO) signal, which contains key cosmological information, based on deep convolutional neural networks (CNN). Trained with almost no fine tuning, the network can recover large-scale modes accurately in the test set: the correlation coefficient between the true and reconstructed initial conditions reaches $90{{\ \rm per\ cent}}$ at $k\le 0.2 \, h\mathrm{Mpc}^{-1}$, which can lead to significant improvements of the BAO signal-to-noise ratio down to $k\simeq 0.4\, h\mathrm{Mpc}^{-1}$. Since this new scheme is based on the configuration-space density field in sub-boxes, it is local and less affected by survey boundaries than the standard reconstruction method, as our tests confirm. We find that the network trained in one cosmology is able to reconstruct BAO peaks in the others, i.e. recovering information lost to non-linearity independent of cosmology. The accuracy of recovered BAO peak positions is far less than that caused by the difference in the cosmology models for training and testing, suggesting that different models can be distinguished efficiently in our scheme. It is very promising that our scheme provides a different new way to extract the cosmological information from the ongoing and future large galaxy surveys.
AstroSat view of IGR J17091−3624 and GRS 1915 + 105: decoding the ‘pulse’ in the ‘Heartbeat State’
Authors: Katoch Tilak , Baby Blessy E , Nandi Anuj , Agrawal Vivek K , Antia H M , Mukerjee Kallol
Published: December 2020

IGR J17091−3624 is a transient galactic black hole which has a distinct quasi-periodic variability known as ‘heartbeat’, similar to the one observed in GRS 1915 + 105. In this paper, we report the results of ∼125 ks AstroSat observations of this source during the 2016 outburst. For the first time, a double-peaked QPO (DPQ) is detected in a few time segments of this source with a difference of δf  ∼ 12 mHz between the two peaks. The nature of the DPQ was studied based on hardness ratios and using the static as well as the dynamic power spectrum. Additionally, a low-frequency (25–48 mHz) ‘heartbeat’ single-peak QPO (SPQ) was observed at different intervals of time along with harmonics (50–95 mHz). Broad-band spectra in the range 0.7–23 keV, obtained with Soft X-ray Telescope and Large Area X-ray Proportional Counter, could be fitted well with combination of a thermal Comptonization and a multicolour disc component model. During AstroSat observation, the source was in the soft-intermediate state (SIMS) as observed with Swift/XRT. We present a comparative study of the ‘heartbeat’ state variability in IGR J17091−3624 with GRS 1915 + 105. Significant difference in the timing properties is observed although spectral parameters (Γ ∼ 2.1–2.4 and Tmax ∼ 0.6–0.8 keV) in the broad energy band remain similar. Spectral properties of segments exhibiting SPQ and DPQ are further studied using simple phase-resolved spectroscopy which does not show a significant difference. Based on the model parameters, we obtain the maximum ratio of mass accretion rate in GRS 1915 + 105 to that in IGR J17091−3624 as ∼25: 1. We discuss the implications of our findings and comment on the physical origin of these exotic variabilities.
Simple application of adipose-derived stem cell-derived extracellular vesicles coating enhances cytocompatibility and osteoinductivity of titanium implant
Authors: Chen Lifeng , Mou Shan , Hou Jinfei , Fang Huimin , Zeng Yuyang , Sun Jiaming , Wang Zhenxing
Published: December 2020

Surface modification using bioactive molecules is frequently performed to improve the biological properties of medical metal biomaterial titanium (Ti) implants. Developmental evidence suggests that mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) served as potent bioactive component. As a subset of MSC-EV, adipose-derived stem cell-derived extracellular vesicles (ADSC-EVs) could be obtained from abundant adipose tissue. Meanwhile, it possesses multiple regenerative properties and might be used to endow biological activities to medical Ti implant. Here, we present a simple ADSC-EV coating strategy based on physisorption of fibronectin. This ADSC-EV functionalized Ti implants (EV-Ti) revealed enhanced osteoblast compatibility and osteoinductive activity. Cell spreading area of EV-Ti group was 1.62- and 1.48-fold larger than that of Ti group after 6 and 12 h of cell seeding, respectively. Moreover, EV-Ti promoted alkaline phosphatase, collagen 1 and osteocalcin gene expression in osteoblast by 1.51-, 1.68- and 1.82-fold compared with pristine Ti, respectively. Thus, the MSC-EVs modification method reported here provide a clinically translatable strategy to promote the bioactivity of Ti implants.
The study of dry biological valve crosslinked with a combination of carbodiimide and polyphenol
Authors: Yang Li , Xie Shuang , Ding Kailei , Lei Yang , Wang Yunbing
Published: December 2020

The glutaraldehyde crosslinked pericardium has been used in bioprosthetic valves for about 50 years. However, problems such as glutaraldehyde residue and calcification still exist in current commercial products. Non-glutaraldehyde crosslinked dry valve is an important strategy to solve those problems. In this study, a non-glutaraldehyde crosslinked dry biological valve material was obtained by the combined crosslinking of carbodiimide (EDC) and polyphenol. The results showed that the comprehensive properties of EDC and curcumin crosslinked pericardium were superior to glutaraldehyde crosslinked pericardium, including unfolding property, anti-calcification, cytotoxicity, anticoagulant properties, mechanical properties, enzyme degradation resistance and thermal shrinkage temperature. EDC and curcumin crosslinked dry pericardium could flatten after being folded at 40°C for 3 days while glutaraldehyde crosslinked pericardium could not. The calcification of pericardium treated with EDC and curcumin was 1.21 ± 0.36 mg/g in rats after 60 days’ subdermal implantation, much lower than that of glutaraldehyde treated control group (22.06 ± 3.17 mg/g).
Concurrent Retropubic Midurethral Sling and OnabotulinumtoxinA for Mixed Urinary Incontinence
Authors: Komar Alix , Bretschneider Carol E. , Mueller Margaret G. , Lewicky-Gaupp Christina , Collins Sarah , Geynisman-Tan Julia , Tavathia Meera , Kenton Kimberly
Published: December 2020

OBJECTIVE:

To evaluate whether retropubic midurethral sling combined with onabotulinumtoxinA is more effective than sling alone in improving mixed urinary incontinence symptoms.

METHODS:

We conducted a prospective, double-blind, randomized, controlled trial of women with mixed urinary incontinence, planning to undergo midurethral sling. Women were randomly assigned to receive 100 unites of intradetrusor onabotulinumtoxinA or placebo during surgery. Participants completed the PGI-S (Patient Global Impression of Severity), the UDI-6 (Urinary Distress Inventory, Short Form), and the PFIQ-7 (Pelvic Floor Impact Questionnaire–Short Form 7) before and 3 months after surgery, and the primary outcome, PGI-I (Patient Global Impression of Improvement), 3 months postoperatively. Primary outcome was PGI-I score at 3 months for overall incontinence. We considered women “improved” with answers of “very much better” or “much better” on the PGI-I. Assuming a PGI-I response of “improved” in 66% of placebo and 93% of onabotulinumtoxinA participants, 68 women were needed to show a significant difference with 80% power at 0.05 significance level.

RESULTS:

From March 2016 to November 2019, 78 women completed a 3-month follow-up (onabotulinumtoxinA: 41; placebo: 37). Mean age was 51 years (±10). On the PGI-I, the number who “improved” did not differ between groups at 3 months (83% vs 84%, P=1.0). The onabotulinumtoxinA group had less severe urgency symptoms as indicated by median urgency PGI-S scores (1 [interquartile range 1–2] vs 2 [interquartile range 1–3], P=.033) and greater improvement in urgency symptoms based on median urgency PGI-I score (1 [interquartile range 1–3] vs 2 [interquartile range 2–4], P=.028). At 3 months, median UDI-6, PFIQ-7, and PGI-S scores improved significantly from baseline in both groups. Similarly, UDI-6 and PFIQ-7 scores did not differ between groups. More women in the onabotulinumtoxinA arm initiated intermittent self-catheterization, (3% placebo; 12% onabotulinumtoxinA, P=.20) and experienced urinary tract infections (5% placebo; 22% onabotulinumtoxinA, P=.051), but these did not differ statistically.

CONCLUSION:

Concurrent intradetrusor onabotulinumtoxinA injection did not improve overall incontinence symptoms at 3 months compared with placebo among women with mixed urinary incontinence undergoing midurethral sling placement. Women with mixed urinary incontinence undergoing sling report significant improvement in overall incontinence symptoms, regardless of the addition of onabotulinumtoxinA injections, but those receiving concurrent onabotulinumtoxinA injections reported less urgency severity and greater improvement in urgency symptoms at 3 months.

CLINICAL TRIAL REGISTRATION:

ClinicalTrials.gov, NCT02678377.
Preoperative Pelvic Floor Injections With Bupivacaine and Dexamethasone for Pain Control After Vaginal Prolapse Repair
Authors: Giugale Lauren E. , Baranski Lindsey A. , Meyn Leslie A. , Schott Nicholas J. , Emerick Trent D. , Moalli Pamela A.
Published: December 2020

OBJECTIVE:

To test the hypothesis that preoperative pelvic floor muscle injections and pudendal nerve blocks with bupivacaine and dexamethasone would decrease postoperative pain after vaginal native tissue prolapse repairs, compared with saline and bupivacaine.

METHODS:

We conducted a three-arm, double-blind, randomized trial of bilateral transobturator levator ani muscle injections and transvaginal pudendal nerve blocks before vaginal reconstructive and obliterative prolapse procedures (uterosacral ligament suspension, sacrospinous ligament fixation, levator myorrhaphy, or colpocleisis). Women were randomized to one of three study medication groups: 0.9% saline, 0.25% bupivacaine, or combination 0.25% bupivacaine with 4 mg dexamethasone. Our primary outcome was a numeric rating scale pain score on postoperative day 1. Using an analysis of variance evaluated at the two-sided 0.05 significance level, an assumed variance of the means of 0.67, and SD of 1.75, we calculated 21 women per arm to detect a 2-point change on the numeric rating scale (90% power), which we increased to 25 per arm to account for 20% attrition and the use of nonparametric statistical methods.

RESULTS:

From June 2017 through April 2019, 281 women were screened and 75 (26.7%) were randomized with no differences in baseline demographics among study arms. There was no significant difference in median pain scores on postoperative day 1 among study groups (median [interquartile range] pain score 4.0 [2.0–7.0] for placebo vs 4.0 [2.0–5.5] for bupivacaine vs 4.0 [1.5–5.0] for bupivacaine with dexamethasone, P=.92).

CONCLUSION:

Preoperative pelvic floor muscle injections and pudendal nerve blocks with bupivacaine and dexamethasone did not improve postoperative pain after vaginal native tissue prolapse procedures.

CLINICAL TRIAL REGISTRATION:

ClinicalTrials.gov, NCT03040011.
The “Spinal Metastasis Invasiveness Index”
Authors: Kumar Naresh , Ramos Miguel Rafael David , Patel Ravish , Tan Barry Wei Loong , Lopez Keith Gerard , Nolan Colum Patrick , Kumar Aravind , Kumar Dinesh Shree , Liu Gabriel , Benneker Lorin Michael
Published: December 2020

Study Design.

Retrospective review.

Objective.

The aim of this study was to develop a surgical invasiveness index for metastatic spine tumor surgery (MSTS) that can serve as a standardized tool in predicting intraoperative blood loss and surgical duration; for the purpose of ascertaining resource requirements and aiding in patient education.

Summary of Background Data.

Magnitude of surgery is important in the metastatic spine disease (MSD) population since these patients have a continuing postoperative oncological process; a consideration that must be taken into account to maintain or improve quality of life. Surgical invasiveness indices have been established for general spine surgery, adult deformity, and cervical deformity, but not yet for spinal metastasis.

Methods.

Demographic, oncological, and procedural data were collected from consecutive patients that underwent MSTS. Binary logistic regression, using median values for surgical duration and intraoperative estimated blood loss (EBL), was used to determine statistical significance of variables to be included in the “spinal metastasis invasiveness index” (SMII). The corresponding weightage of each of these variables was agreed upon by experienced spine surgeons. Multivariable regression analysis was used to predict operative time and EBL while controlling for demographical, procedural, and oncological characteristics.

Results.

Two hundred and sixty-one MSD patients were included with a mean age of 59.7-years and near equal sex distribution. The SMII strongly predicted extended surgical duration (R
2 = 0.28, P < 0.001) and high intraoperative blood loss (R
2 = 0.18, P < 0.001). When compared to a previously established surgical invasiveness index, the SMII accounted for more variability in the outcomes. For every unit increase in score, there was a 42-mL increase in mean blood loss (P < 0.001) and 5-minute increase in mean operative time (P < 0.001).

Conclusion.

Long surgical duration and high blood loss were strongly predicted by the newly developed SMII. The use of the SMII may aid in preoperative risk assessment with the goal of improving patient outcomes and quality of life.

Level of Evidence: 4
Long-term Outcome of Ahmed Glaucoma Valve Implantation in Eyes With Intractably Raised Intraocular Pressure Following Pars Plana Vitrectomy
Authors: Pandav Surinder S. , Thattaruthody Faisal , Singh Simar R. , Chandra Kedarisetti K. , Seth Natasha G. , Kaur Savleen , Kaushik Sushmita , Raj Srishti
Published: December 2020

Precis:

Ahmed glaucoma valve (AGV) implantation led to a significant reduction in intraocular pressure (IOP) and in antiglaucoma medications in vitrectomized eyes in previously nonglaucomatous eyes. The most common indication for vitrectomy was ocular trauma-related complications.

Purpose:

The purpose of this study was to report the long-term outcomes of AGV implantation in patients of uncontrolled IOP after pars plana vitrectomy (PPV).

Materials and Methods:

Medical records of patients (age 18 y and above) who underwent AGV implantation between January 2006 and December 2017 for uncontrolled IOP following PPV with ≥2 years follow-up were reviewed. The underlying etiology for PPV, IOP, best-corrected visual acuity, and number of antiglaucoma medications (AGMs) were recorded at baseline. The main outcomes measures were IOP, number of AGM, best-corrected visual acuity, and postoperative complications. Postoperative complications were classified as early (≤3 mo)/intermediate (>3 mo to ≤1 y), or late (>1 y).

Results:

In all, 78 eyes of 78 patients with a mean age of 38.06±17.83 years were included. The mean follow-up was 70.46±36.96 (range: 24 to 180) months. The main underlying etiology for PPV was trauma (38.4%) followed by rhegmatogenous retinal detachment (28.2%). The mean preoperative IOP was 29.33±9.84 mm Hg with an average of 4.07±1.2 AGM. The mean IOP and number of AGM was significantly reduced in all follow-up visits (P<0.0001) following AGV implantation. The cumulative probability of success was 92.3%, 80.7%, and 74% at 2, 5, and 10 years, respectively. Thirty-one complications were observed in 25 (32%) eyes and reoperation (23 procedures) was performed in 22 (28.2%) eyes.

Conclusions:

AGV implantation had good outcome in patients with intractably elevated IOP following PPV. Trauma-related pathologies were a major contributor to the indications for PPV and had more chances of failure following AGV implantation.