bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of the energy consumption in the production of natural and recycled concrete aggregate: A case study in Kerala, India
Authors: Ittyeipe Alan V , Thomas Anu V , Ramaswamy K P
Published: December 2020

The growth of construction sector in India is gaining pace to cater to the overwhelming demands of the rising urban population and this has in turn resulted in overexploitation of natural resources for production of natural aggregates (NA). The prospects of recycling demolition debris to produce recycled concrete aggregate (RCA) is little explored, due to the underestimation of actual data on the construction and demolition (C&D) waste generated in India. The different stages involved in the production of NA and RCA were investigated by field study in an aggregate quarry and a demolition site in Kerala, India. The energy consumption involved in the recycling of the demolition debris from a reinforced concrete (RC) structure and the production of NA was determined. The energy consumed to produce 1 tonne of NA and RCA was determined as 21112 KJ/tonne and 16178 KJ/tonne respectively. The production of RCA showed a 30.5% savings in the energy consumption compared to that of NA. A specific sensitivity analysis suggested that the energy consumed to produce RCA was less than that to produce NA for a maximum distance of 13.5 km. As the energy consumption was evaluated based on the diesel consumption of the machinery involved, the reduced diesel consumption and its subsequent cost savings could also add to the prospects of using RCA. Although the results are site specific, such local case studies could contribute to the development of C&D waste recycling infrastructure in the country.
Mechanical properties of alkali-activated mortar in organic acid environment
Authors: Ajay Athira , Ramaswamy K P , Thomas Anu V
Published: December 2020

Ingression of acid into the concrete results in early degradation by microstructural alteration of phases leading to mass changes, weakening of mechanical properties and increase in porosity due to calcium leaching. This paper discusses the resistance of geopolymer composites (GP) and conventional concrete system (OPC) in 0.125M and 0.25M concentrations of acetic acid medium by investigating the changes in the mechanical properties of mortar. The results of the study reveal that the GP samples display increased resistance to acetic acid attack not only in terms of mass and strength loss but also with reference to the variation in ultrasonic pulse velocity and relative dynamic modulus of elasticity. The results also manifest that blends of ground granulated blast furnace slag (GGBS) and fly ash (class F) (FA) with red mud (RM) offer increased acid resistance due to the nature of the main binder gel produced in GP systems.
An experimental study on assessing the corrosion performance of steel reinforcement for the durability of concrete
Authors: Naveen Kumar V , Daniel Ronald Joseph J , Ashok M , Suresh Kumar MP
Published: December 2020

Durability of structures made of steel-reinforced concrete is greatly to scale back the speed of moisture transport or the ingress of aggressive ions. An experimental study to assess the initial corrosion behaviour of Thermo-Mechanically Treated rebar (TMT), Corrosion Resistant rebar (CRS) and Fusion bonded Epoxy Coated rebar (EC) under controlled condition (CC) and in simulated marine environment condition (SME). Rebars of 12 mm dia with a span of 250 mm are enclosed in specimens having and length and breadth of 350 mm and a thickness of 138 mm then initial study was carried out. The corrosion potential is noted throughout the specified duration and once in three days of observing the corrosion potential gives the likelihood of corrosion rise. The A. C Impedance and Polarization resistance methods are used to study the corrosion rate in the surface of the rebar. The polarisation resistance (Rp) of TMT rebar is found to be 1.8 times but that of CRS rebar. A. C Impedance used for EC showed that epoxy coating is harmed and affected because of chloride attack. Initial quantitative study from this research gives clear interpretation of rust production which can be utilized in fragility of the structure.
Imitation model for keystroke dynamics base on state context representation
Authors: Pashchenko Dmitry V. , Martyshkin Alexey I. , Trokoz Dmitry A. , Balzannikova Elena A.
Published: December 2020

This paper describes different methods of keystroke dynamics. As part of a study on the development of methods for the dynamic analysis of keystroke dynamics, a method is proposed for representing the process of typing on the keyboard in the form of a successive change of states. Based on states it is proposed to define certain sequences called the state context as feature of a biometric image.

Based on this representation, an imitation model of keystroke dynamics was developed, which allows replacing the physical source of biometric data for the purpose of testing and debugging the identification system of keystroke dynamics
Frequency Analysis of Hydraulic Modeling As A Way to Forecast Flooding on the Allala River
Authors: Abdennour Kastali , Ayoub Zeroual , Lyudmila Kravchenko , Anna Khadzhidi , BoukhanefIssam
Published: December 2020

The article presents research on modeling the recurrence of emergency situations caused by flooding on the Allala river. It is proposed to predict the frequency of floods using the Saint-Venant equation for hydrodynamic modeling. The HEC RAS model was used to compare flood intensity with different water level positions in the river. The parameters of the water source were measured on a section of 8 km long. As a result of research, it was found that the existing coastal protection structures on the banks of the Allala river are insufficient to prevent an emergency flood situation at peak river flows.
Closed Loop Control of PV System Using Grey Wolf Optimization Algorithm under Partial Shading Condition
Authors: Jayaudhaya Dr. J. , Rajasekaran D. , Sumithra J. , Vinitha J. C. , Karkuzhali S.
Published: December 2020

Globally there is an increased awareness of the havoc that climate change and rising pollution are due to the over consumption of carbon riddled fossil fuels making the environment unfit for living. Thus, it is important to make discerning choices to incorporate more clean energy to produce power. Therefore, Renewable energy emerges as an obvious alternative. Renewable resources like solar and wind are now being utilized for power generation. The power output of a solar panel depends on the amount of irradiance of sunlight which is also called insolation. The main drawback in solar is the power output of a PV panel for a particular irradiance is not a linear function of voltage and the power is maximum only at a particular voltage called optimum voltage. When the solar panel is subjected to non-uniform irradiance which is referred to us partial shaded condition, then there will be multiple power peaks in the P-V characteristics and it becomes unable to meet the load requirements. The proposed system will help to overcome this drawback as it consists of two cascaded boost converters. A battery is connected in parallel to output of MPPT boost converter so that load power demand is met by parallel combination of PV panel and battery. The system is optimized for best performance using multi objective GWO optimization technique. Thus, maximum power is extracted even under partial shading condition and constant power is supplied.
Design and Modelling of Multi-Source Self-Charging Electric Bike
Authors: Thiyagesan M , Nair Akshaya R , Kumar Mr. Akshay , r Ms. Vanitha
Published: December 2020

The concept of electric vehicles is not new to us, the 1st documented electric vehicle was in the late 1890s, electric vehicles were far forgotten and suppressed for so long because of the domination of conventional vehicles in the commercial market. Conventional vehicles are fuelled by petroleum products which are non-renewable and not much environment friendly. We have reached a situation where we cannot depend on these fast depleting non-renewable sources of energy for better future. Hence, we are in need to develop and utilize the renewable sources of energy that are less/non-polluting and does not get depleted. Only by the late 1960s, people started to realize the need for electric vehicles. Electric vehicles are a better replacement or the conventional vehicles and are more efficient and Eco-friendlier.
Contigency Analysis in Multiline Distributed System using Dynamic Voltage Restorer
Authors: Antony Charles A , Joshua Jeyasekar D , Ramya G , Suresh P , Manimaran B
Published: December 2020

Power system security analysis involves a vital role in improving the system security and helps preventing the system collapse condition. This paper shows the conception and simulation of nine bus system with generator outage contingency. The objective of this work is to improve the real and reactive powers by employing DVR. Nine bus systems with generator outage contingency condition healthy, unhealthy without IDVR and unhealthy with DVR are simulated. The comparative study is presented to demonstrate the improvement in the power quality by adding DVR. The results indicate that real and reactive powers are improved by adding DVR.
Radio Frequency Identification (RFID) based ubiquitous health care data handling
Authors: Tamilvizhi T , Surendran R , Bommi R M
Published: December 2020

The Health care data is a most important and essential data compare with other types of data in the world. So the Health care Industry need to increase the data handling ability with a help of modern techniques. The Health care data handling must be improve with modern techniques like Cloud Computing and Radio Frequency Identification (RFID). The proposed framework merge the features of Cloud computing and RFID. The proposed framework provide the unique features to achieve the efficient data handling. RFID establish the data collection process from varies medical devices or centers. The cloud computing provide storage facility for Healthcare. The security feature is provided by the RFID for Healthcare data. Here Ubiquitous health care data accessibility represents the health care data can be access at anywhere, anytime, and from anything in Cloud computing. The proposed framework provide security in the form of the RFID tag to the patients and medical devices/centers. The RFID provides the security for the following data’s like patient records, doctors and nurse details caring the patient and hospital bed details. The proposed data handling produces the higher data accuracy, richer security and less energy consumption with help of Quality of Service factors.
A Contrast Adjusted Wavelet and Curvelet Transform Based Fusion of Breast Images
Authors: Vijayalakshmi G. , Shanthakumar M. , Muthukumar K.
Published: December 2020

Restoration is one of the image processing techniques to restore the distorted image. The distorted image can be any type like blurred image, noise added either while storing or capturing of the images. the traditional restoration techniques are geometric correction, different types of filters to remove the noises. Generally, the restoration is applied to the single image to retrives its information. In this, the restoration process is applied in the application of image fusion of medical images. the reason to chose the image fusion process is to improve its entropy. The medical images used in this paper is the mammogram and MRI-breast image. In this, the image fusion is performed with the help of wavelet and curvelet transform. The curvelet transform is applied to the restored mammogram image with the help of contrast adjusted top-hat filter process. The wavelet transform is applied to the MRI image because it has more volume of data to acquire important details. The fused image is evaluated with the help of entropy, mean standard deviation and variance. The fused image has efficient value as compared to its original image but it is higher than the DTCWT-fused image. To verify the quality of the proposed method, the psnr is evaluated to determine the noise present in the image. From the evaluation, the noise is less and entropy is higher in the proposed method. Hence, the contrast adjusted wavelet curvelet fusion is the best restoration and fusion process in the breast images.
Effective Timer Count Scheduling with Spectator Routing Using Stifle Restriction Algorithm in Manet
Authors: Anand R. P. Prem , Rajaram A.
Published: December 2020

Mobile nodes are provides unstable communication among mobile nodes, since nodes energy levels are abnormally changed. So, difficult to manage those node activities, packets are missed to collect by target node. Multi packet is broadcasted by sender node is not easy to manage frequently, since it does not have high capacity nodes. It reduces packet integrity rate, and network lifetime. In proposed algorithm is Timer count scheduling with spectator routing (TCSSR) scheme. Spectator monitors the packet transmission use of timer count. Clustering method is used to main stability for all mobile nodes available in coverage area. Stifle restriction algorithm is used to maintaining information about communication nodes, continuous sequence used to limiting sharing of the residence state of a communicate shields. Effective path selects for communication with the support of timer count report is analyzed. It enhances packet integrity rate, and network lifetime.
Application of hyperoperations for engineering practice
Authors: Rubtsov Konstantin A. , Konstantinov Igor S. , Lazarev Sergey A. , Polshchykov Konstantin A. , Kiselev Vladimir E.
Published: December 2020

This article presents some of the main points of the study for the practical application of various hyperoperations in engineering practice. The authors examined the use of hyperoperations in mathematical formalization of analytical solutions of branching algorithms, the use of new number formats for encoding information based on large numbers. The methods of applying hyperoperations considered by the authors allow them to be effectively used on modern microprocessor-based computers with a built-in mathematical coprocessor, which is an integral part of the processor core, which allows implementing algorithms based on operations of the order higher than “addition” and “subtraction”.
Design of 12T SRAM cell for low power dissipation
Authors: Suresh Kumar R , Ranjani K , Rasheedha A
Published: December 2020

The present semiconductor industry is developing quite quickly. Mobile and portable devices are becoming small for each day and moreover there is a rising demand for extended battery power. With these demands it is significant for researchers to emphasis on the leakage capacity in standby mode. For the exact communication, SRAM was intended with DSP, processor and applications with low power devices. The design engineer emphases mostly on the making of low energy consuming, higher bandwidth and large memory capacity. Memory is an essential part of majority of these systems as well asit is also reduced as the system size reduces. High processing architecture as well as low power is consequently a foremost concern. The robustness of static random access memory cells is other important factor. This paper proposed the architecture design of 12T SRAM for the reduction minimization of power leakages or power consumption during the sleep transistor. This supports in the minimization of the leakage in the CMOS transistor. Based on the parameters like write delay, read delay, write voltage, read voltage, and power consumption at various temperature are compared to the existing SRAM architecture of 6T, 7T and 8T, we acquire reduced power consumption in the proposed 12T SRAM architecture..
Tuning electro-mechanical properties of EAP-based haptic actuators by adjusting layer thickness and number of stacked layers—a comparison
Authors: Stubning Tobias , Denes Istvan , Gerhard Reimund
Published: December 2020

In our fast-changing world, human-machine interfaces (HMIs) are of ever-increasing importance. Among the most ubiquitous examples are touchscreens that most people are familiar with from their smartphones. The quality of such an HMI can be improved by adding haptic feedback—an imitation of using mechanical buttons—to the touchscreen. Thin-film actuators on the basis of electro-mechanically active polymers (EAPs), with the electroactive material sandwiched between two compliant electrodes, offer a promising technology for haptic surfaces. In thin-film technology, the thickness and the number of stacked layers of the electroactive dielectric are key parameters for tuning a system. Therefore, we have experimentally investigated the influence of the thickness of a single EAP layer on the electrical and the electro-mechanical performance of the transducer. In order to achieve high electro-mechanical actuator outputs, we have employed relaxor-ferroelectric ter-fluoropolymers that can be screen-printed. By means of a model-based approach, we have also directly compared single- and multi-layer actuators, thus providing guidelines for optimized transducer configurations with respect to the system requirements of haptic applications for which the operation frequency is of particular importance.
From Litigation to Rights: The Case of the European Court of Human Rights
Authors: Haglund Jillienne , Welch Ryan M
Published: December 2020

Do regional human rights courts influence respect for rights? Beyond providing remedy for individual human rights abuse, case outcomes help frame potential social mobilization by setting standards and raising the rights consciousness of civil society actors. The expectation of mobilization can increase the government’s costs of flouting the court’s rulings. We argue that an enabling domestic environment characterized by two features increases government expectation of mobilization following regional court litigation. First, a robust civil society creates strong horizontal ties between potential mobilizing groups. Second, a national human rights institution (NHRI) creates vertical ties that both transfer information down from the court to civil society; and transfer demands up from civil society to political elites in position to make stronger human rights policy. Using data for all Council of Europe countries from 1980 to 2012, we find European Court of Human Rights litigation associated with higher respect for rights in an enabling domestic environment characterized by strong civil society and the presence of a NHRI.
The FDA MyStudies app: a reusable platform for distributed clinical trials and real-world evidence studies
Authors: Wyner Zachary , Dublin Sascha , Chambers Christina , Deval Shyam , Herzig-Marx Chayim , Rao Shanthala , Rauch Adam , Reynolds Juliane , Brown Jeffrey S , Martin David
Published: December 2020

We developed a mobile application and secure patient data storage platform, FDA MyStudies, to address privacy, engagement, and extensibility challenges in mobile clinical research. The system extends the capabilities of the mobile frameworks Apple ResearchKit and ResearchStack through an intuitive front-end application and secure storage environment that can support health research studies. The platform supports single or multisite studies via role-based access and can be implemented within highly secure data environments. As a proof-of-concept, pregnant women participated in a descriptive study via the app in which data not routinely captured in electronic health records (EHR) were collected and linked with existing patient data to provide a more wholistic view of the patient and illustrate how patient data combined with EHR data could be used to support public health research.
Religion at Work in Bioethics and Biopolicy: Christian Bioethicists, Secular Language, Suspicious Orthodoxy
Authors: Blackford Russell , Schüklenk Udo
Published: December 2020

The proper role, if any, for religion-based arguments is a live and sometimes heated issue within the field of bioethics. The issue attracts heat primarily because bioethical analyses influence the outcomes of controversial court cases and help shape legislation in sensitive biopolicy areas. A problem for religious bioethicists who seek to influence biopolicy is that there is now widespread academic and public acceptance, at least within liberal democracies, that the state should not base its policies on any particular religion’s metaphysical claims or esoteric moral system. In response, bioethicists motivated by religious concerns have adopted two identifiable strategies. Sometimes they rely on slippery-slope arguments that, sometimes at least, have empirically testable premises. A more questionable response is the manipulation and misuse of secular-sounding moral language, such as references to “human dignity,” and the plights of groups of people labeled “vulnerable.”
Technological issues
Authors: Scherrenberg Martijn , Bonneux Cindel , Frederix Ines , Dendale Paul
Published: December 2020

Technology has become increasingly important in cardiac rehabilitation (CR). New technologies, such as smartwatches, have changed the landscape of real-time monitoring of ambulatory patients. Implementation of new technology is always accompanied by issues of concern. Relevant examples are inter-operability and data protection. However, new technologies mainly offer new opportunities such as improvements in tele-rehabilitation (teleCR), persuasive design and big data analysis.
The EXPERT tool: how to make exercise prescription easy
Authors: Hansen Dominique , Coninx Karin
Published: December 2020

Exercise training (ET) is a cornerstone of the multidisciplinary rehabilitation of patients with and at risk of cardiovascular disease (CVD). However, evidence indicates that clinicians experience difficulties in prescribing exercise for patients with different CVDs and risk factors (RFs). Different exercise intensities, duration, volume, frequency, and type will lead to different changes in CVD RFs. The Exercise Prescription in Everyday Practice & Rehabilitative Training (EXPERT) tool has been developed to overcome this limitation. It is a potential method for encouraging standardization of exercise prescription in CVD (risk) and enhancing the implementation of integrated exercise guidelines into clinical practice. The aim of this chapter is to guide clinicians on how to use the EXPERT tool to optimize their exercise prescription (skills).
Validation of the Strawberry Advisory System in the Mid-Atlantic Region
Authors: Hu Mengjun , Cosseboom Scott D. , Schoeneberg Anita , Johnson Charles S. , Peres Natalia A. , Lea-Cox John
Published: December 2020

Anthracnose fruit rot (AFR) and Botrytis fruit rot (BFR) are primary diseases affecting strawberry (Fragaria × ananassa), which typically drive fungicide applications throughout the growing season. The Strawberry Advisory System (StAS), a disease forecasting tool, was originally developed in Florida to better time the fungicide sprays by monitoring AFR and BFR infection risk based on leaf wetness and temperature input in real-time. Thirteen field trials were conducted in Maryland and Virginia between 2017 and 2019 to evaluate the StAS performance in the Mid-Atlantic region. As a result, 55, 18, and 31% fewer sprays were recorded on average in the model-based StAS treatment compared with the grower standard treatment in 2017, 2018, and 2019, respectively. Marketable yield, as well as AFR and BFR incidence, were largely comparable between the two treatments. However, poor disease control occurred during the StAS treatment in four trials in 2017, presumably because of a missed fungicide spray during a high-risk infection event and attributable to heavy rainfall that led to impassable fields. The implementation of the StAS may be further challenged by the employment of floating row covers that are essential for growing strawberries in plasticulture systems in open fields in the Mid-Atlantic region. Preliminary results indicated that row covers can alter canopy-level microclimatic conditions, possibly increasing the risk for disease occurrence. Overall, the StAS can be a valuable tool for Mid-Atlantic growers to control AFR and BFR, but sprays may need to be promptly applied when consecutive or heavy rainfalls are predicted, especially for highly susceptible cultivars. Complications in disease forecasting and management arising from the use of row covers need to be further addressed in this region because of its highly diverse climate.
Uterine fibroids increase the risk of hypertensive disorders of pregnancy: a prospective cohort study
Authors: Chen Yequn , Lin Mengyue , Guo Pi , Xiao Jiaxin , Huang Xiru , Xu Lan , Xiong Nianling , O’Gara Mary Clare , O’Meara Michael , Tan Xuerui
Published: December 2020

Objective:

It is unclear whether uterine fibroids are associated with the occurrence of hypertensive disorders of pregnancy (HDP). Thus, this study aimed to evaluate the association between uterine fibroids and HDP in a prospective cohort.

Methods:

Overall, 2404 pregnant women who received antenatal care were enrolled in a prospective cohort in China between 2014 and 2016; 2277 women met the inclusion criteria of this study. The clinical characteristics of participants were assessed via questionnaires and physical examinations at baseline (before the 20th week of gestation), 21st–27th, 28th–34th, and 35th–39th gestational weeks. Ultrasound examination was performed before the 20th week of pregnancy to determine the presence of uterine fibroids. Linear mixed-effect and Cox proportional hazard regression models were used to analyze the association of uterine fibroids with blood pressure and HDP.

Results:

Of 2277 pregnant women, 242 (10.6%) had uterine fibroids, and 45 (2.0%) subsequently developed HDP. The incidence of HDP in women with and without uterine fibroids was 5% (n = 12) and 1.6% (n = 33), respectively. The longitudinal SBPs and DBPs were significantly higher in women with uterine fibroids than in those without. The multivariable Cox model showed that the presence of uterine fibroids was associated with increased HDP risk (adjusted hazard radio: 2.95, 95% confidence interval: 1.35–6.44).

Conclusion:

Uterine fibroids in early pregnancy were associated with an increased HDP risk. Blood pressure of women with uterine fibroids should be closely monitored, and HDP preventive measures are crucial.
Towards blood flow in the virtual human: efficient self-coupling of HemeLB
Authors: McCullough J. W. S. , Richardson R. A. , Patronis A. , Halver R. , Marshall R. , Ruefenacht M. , Wylie B. J. N. , Odaker T. , Wiedemann M. , Lloyd B. , Neufeld E. , Sutmann G. , Skjellum A. , Kranzlmüller D. , Coveney P. V.
Published: December 2020

Many scientific and medical researchers are working towards the creation of a virtual human—a personalized digital copy of an individual—that will assist in a patient’s diagnosis, treatment and recovery. The complex nature of living systems means that the development of this remains a major challenge. We describe progress in enabling the HemeLB lattice Boltzmann code to simulate 3D macroscopic blood flow on a full human scale. Significant developments in memory management and load balancing allow near linear scaling performance of the code on hundreds of thousands of computer cores. Integral to the construction of a virtual human, we also outline the implementation of a self-coupling strategy for HemeLB. This allows simultaneous simulation of arterial and venous vascular trees based on human-specific geometries.
Deep medical image analysis with representation learning and neuromorphic computing
Authors: Getty N. , Brettin T. , Jin D. , Stevens R. , Xia F.
Published: December 2020

Deep learning is increasingly used in medical imaging, improving many steps of the processing chain, from acquisition to segmentation and anomaly detection to outcome prediction. Yet significant challenges remain: (i) image-based diagnosis depends on the spatial relationships between local patterns, something convolution and pooling often do not capture adequately; (ii) data augmentation, the de facto method for learning three-dimensional pose invariance, requires exponentially many points to achieve robust improvement; (iii) labelled medical images are much less abundant than unlabelled ones, especially for heterogeneous pathological cases; and (iv) scanning technologies such as magnetic resonance imaging can be slow and costly, generally without online learning abilities to focus on regions of clinical interest. To address these challenges, novel algorithmic and hardware approaches are needed for deep learning to reach its full potential in medical imaging.
Applicability assessment of a stent-retriever thrombectomy finite-element model
Authors: Luraghi Giulia , Rodriguez Matas Jose Felix , Dubini Gabriele , Berti Francesca , Bridio Sara , Duffy Sharon , Dwivedi Anushree , McCarthy Ray , Fereidoonnezhad Behrooz , McGarry Patrick , Majoie Charles B. L. M. , Migliavacca Francesco ,   on behalf of the INSIST investigators
Published: December 2020

An acute ischaemic stroke appears when a blood clot blocks the blood flow in a cerebral artery. Intra-arterial thrombectomy, a mini-invasive procedure based on stent technology, is a mechanical available treatment to extract the clot and restore the blood circulation. After stent deployment, the clot, trapped in the stent struts, is pulled along with the stent towards a receiving catheter. Recent clinical trials have confirmed the effectiveness and safety of mechanical thrombectomy. However, the procedure requires further investigation. The aim of this study is the development of a numerical finite-element-based model of the thrombectomy procedure.
In vitro
thrombectomy tests are performed in different vessel geometries and one simulation for each test is carried out to verify the accuracy and reliability of the proposed numerical model. The results of the simulations confirm the efficacy of the model to replicate all the experimental setups. Clot stress and strain fields from the numerical analysis, which vary depending on the geometric features of the vessel, could be used to evaluate the possible fragmentation of the clot during the procedure. The proposed
in vitro
/
in silico
comparison aims at assessing the applicability of the numerical model and at providing validation evidence for the specific
in vivo
thrombectomy outcomes prediction.
Coupling one-dimensional arterial blood flow to three-dimensional tissue perfusion models for
in silico
trials of acute ischaemic stroke
Authors: Padmos Raymond M. , Józsa Tamás I. , El-Bouri Wahbi K. , Konduri Praneeta R. , Payne Stephen J. , Hoekstra Alfons G.
Published: December 2020

An acute ischaemic stroke is due to the sudden blockage of an intracranial blood vessel by an embolized thrombus. In the context of setting up
in silico
trials for the treatment of acute ischaemic stroke, the effect of a stroke on perfusion and metabolism of brain tissue should be modelled to predict final infarcted brain tissue. This requires coupling of blood flow and tissue perfusion models. A one-dimensional intracranial blood flow model and a method to couple this to a brain tissue perfusion model for patient-specific simulations is presented. Image-based patient-specific data on the anatomy of the circle of Willis are combined with literature data and models for vessel anatomy not visible in the images, to create an extended model for each patient from the larger vessels down to the pial surface. The coupling between arterial blood flow and tissue perfusion occurs at the pial surface through the estimation of perfusion territories. The coupling method is able to accurately estimate perfusion territories. Finally, we argue that blood flow can be approximated as steady-state flow at the interface between arterial blood flow and tissue perfusion to reduce the cost of organ-scale simulations.
Integration of rare large-effect expression variants improves polygenic risk prediction
Authors: Smail Craig , Ferraro Nicole M. , Durrant Matthew G. , Rao Abhiram S. , Aguirre Matthew , Li Xin , Gloudemans Michael J. , Assimes Themistocles L. , Kooperberg Charles , Reiner Alexander P. , Hui Qin , Huang Jie , O’Donnell Christopher J. , Sun Yan V. ,   Million Veteran Program, Rivas Manuel A. , Montgomery Stephen B.
Published: December 2020

Polygenic risk scores (PRS) aim to quantify the contribution of multiple genetic loci to an individual’s likelihood of a complex trait or disease. However, existing PRS estimate genetic liability using common genetic variants, excluding the impact of rare variants. We identified rare, large-effect variants in individuals with outlier gene expression from the GTEx project and then assessed their impact on PRS predictions in the UK Biobank (UKB). We observed large deviations from the PRS-predicted phenotypes for carriers of multiple outlier rare variants; for example, individuals classified as “low-risk” but in the top 1% of outlier rare variant burden had a 6-fold higher rate of severe obesity. We replicated these findings using data from the NHLBI Trans-Omics for Precision Medicine (TOPMed) biobank and the Million Veteran Program, and demonstrated that PRS across multiple traits will significantly benefit from the inclusion of rare genetic variants.
Impact of Convalescent Plasma Transfusion (CCP) In Patients With Previous Circulating Neutralizing Antibodies (nAb) to COVID-19
Authors: Yokoyama Ana Paula H , Wendel Silvano , Bonet-Bub Carolina , Fachini Roberta M , Dametto Ana Paula F , Blumm Fernando , Dutra Valeria F , Candelaria Gabriela , Sakashita Araci M , Machado Rafael Rahal Guaragna , Fontao-Wendel Rita , Hamerschlak Nelson , Achkar Ruth , Assuncao Murillo , Scuracchio Patricia , Nudelman Victor , Pastore Laerte , Pinho Joao R R , Dal Ben Mirian , Filho Roberto Kalil , Marra Alexandre R. , Amano Mariane T. , Kallas Esper , Helito Alfredo Salim , de Carvalho Carlos Roberto Ribeiro , Araujo Danielle Bastos , Durigon Edison Luiz , Camargo Anamaria A , Rizzo Luiz V , Reis Luiz F Lima , Kutner Jose M
Published: December 2020

INTRODUCTION

COVID-19 convalescent plasma (CCP) transfusion has emerged in the past months as an alternative approach to treat pneumonia cases of SARS-CoV-2. Current evidence regarding characteristics of the plasma product, the titer of neutralizing antibodies (nAbs) in the transfused units, time to onset of intervention, and impact of nAbs produced by the patient are limited and heterogeneous.

MATERIAL AND METHODS

We describe the preliminary results of 104 patients with severe pneumonia due to SARS-CoV-2 transfused with CCP at three medical centers in Brazil. All enrolled patients were transfused with doses between 200 mL through 600mL of ABO compatible CCP on days 0-2 after enrolment. Clinical parameters were monitored and nAbs titration was performed using the cytopathic effect-based virus neutralization test with SARS-CoV-2 (GenBankMT126808.1).

RESULTS

Forty-one patients achieved clinical improvement on day 14, and multivariable logistic regression showed that nAbs T (from CCP units transfused) (p= 0.001), nAbs P0 (on day of enrolment) (p=0.009) and use of other supportive therapies (p<0.001) were associated with higher odds for this clinical improvement. Considering ICU length of stay (LOS) and length of mechanical ventilation, in our analysis, nAbs P0 were associated with a significant reduction in ICU LOS (p=0.018) and duration of mechanical ventilation (p<0.001). Administration of CCP after 10 days of symptom onset was associated with increases in ICU length of stay (p<0.001).

DISCUSSION/CONCLUSION

Despite the study limitations, our data have shown an association between patients’ previously acquired nAbs and clinical outcomes. The potential value of timely administration of CCP transfusion before day 10 of disease onset was demonstrated and nAbsP0, but not nAbsT, were associated with ICU LOS, and duration of mechanical ventilation on the improvement of clinical outcomes was also demonstrated. In conclusion, we consider these data are useful parameters to guide future CPP transfusion strategies to COVID-19.
Effect of clustering and correlation of belief systems on infectious disease outbreaks
Authors: Kadelka Claus , McCombs Audrey
Published: December 2020

Contact between people with similar opinions and characteristics occurs at a higher rate than among other people, a phenomenon known as homophily. The presence of clusters of unvaccinated people has been associated with increased incidence of infectious disease outbreaks despite high vaccination coverage. The epidemiological consequences of homophily regarding other beliefs and correlations among belief systems are however poorly understood. Here, we use a simple compartmental disease model as well as a more complex COVID-19 model to study how homophily and correlation of belief systems in a social interaction network affect the probability of disease outbreak and COVID-19-related mortality. We find that the current social context, characterized by the presence of homophily and correlations between who vaccinates, who engages in risk reduction, and individual risk status, corresponds to a situation with substantially worse disease burden than in the absence of heterogeneities. In the presence of an effective vaccine, relative effects of homophily and correlation of belief systems become stronger. Further, the optimal vaccination strategy depends on the degree of homophily regarding vaccination status as well as the relative level of risk mitigation high- and low-risk individuals practice. The developed methods are broadly applicable to any investigation in which node attributes in a graph might reasonably be expected to cluster or exhibit correlations.
BNT162b2 induces SARS-CoV-2-neutralising antibodies and T cells in humans
Authors: Sahin Ugur , Muik Alexander , Vogler Isabel , Derhovanessian Evelyna , Kranz Lena M. , Vormehr Mathias , Quandt Jasmin , Bidmon Nicole , Ulges Alexander , Baum Alina , Pascal Kristen , Maurus Daniel , Brachtendorf Sebastian , Lörks Verena , Sikorski Julian , Koch Peter , Hilker Rolf , Becker Dirk , Eller Ann-Kathrin , Grützner Jan , Tonigold Manuel , Boesler Carsten , Rosenbaum Corinna , Heesen Ludwig , Kühnle Marie-Cristine , Poran Asaf , Dong Jesse Z. , Luxemburger Ulrich , Kemmer-Brück Alexandra , Langer David , Bexon Martin , Bolte Stefanie , Palanche Tania , Schultz Armin , Baumann Sybille , Mahiny Azita J. , Boros Gábor , Reinholz Jonas , Szabó Gábor T. , Karikó Katalin , Shi Pei-Yong , Fontes-Garfias Camila , Perez John L. , Cutler Mark , Cooper David , Kyratsous Christos A. , Dormitzer Philip R. , Jansen Kathrin U. , Türeci Özlem
Published: December 2020

BNT162b2, a lipid nanoparticle (LNP) formulated nucleoside-modified messenger RNA (mRNA) encoding the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein (S) stabilized in the prefusion conformation, has demonstrated 95% efficacy to prevent coronavirus disease 2019 (COVID-19). Recently, we reported preliminary BNT162b2 safety and antibody response data from an ongoing placebo-controlled, observer-blinded phase 1/2 vaccine trial1. We present here antibody and T cell responses from a second, non-randomized open-label phase 1/2 trial in healthy adults, 19-55 years of age, after BNT162b2 prime/boost vaccination at 1 to 30 µg dose levels. BNT162b2 elicited strong antibody responses, with S-binding IgG concentrations above those in a COVID-19 human convalescent sample (HCS) panel. Day 29 (7 days post-boost) SARS-CoV-2 serum 50% neutralising geometric mean titers were 0.3-fold (1 µg) to 3.3-fold (30 µg) those of the HCS panel. The BNT162b2-elicited sera neutralised pseudoviruses with diverse SARS-CoV-2 S variants. Concurrently, in most participants, S-specific CD8+ and T helper type 1 (TH1) CD4+ T cells had expanded, with a high fraction producing interferon-γ (IFNγ). Using peptide MHC multimers, the epitopes recognised by several BNT162b2-induced CD8+ T cells when presented on frequent MHC alleles were identified. CD8+ T cells were shown to be of the early-differentiated effector-memory phenotype, with single specificities reaching 0.01-3% of circulating CD8+ T cells. In summary, vaccination with BNT162b2 at well tolerated doses elicits a combined adaptive humoral and cellular immune response, which together may contribute to protection against COVID-19.
Research on Recognition Method of COVID-19 Images Based on Deep Learning
Authors: Ji Dongsheng , Zhao Yanzhong , Zhang Zhujun , Zhao Qianchuan
Published: December 2020

In view of the large demand for new coronary pneumonia covid19 image recognition samples,the recognition accuracy is not ideal.In this paper,a new coronary pneumonia positive image recognition method proposed based on small sample recognition. First, the CT image pictures are preprocessed, and the pictures are converted into the picture formats which are required for transfer learning. Secondly, perform small-sample image enhancement and expansion on the converted picture, such as miscut transformation, random rotation and translation, etc.. Then, multiple migration models are used to extract features and then perform feature fusion. Finally,the model is adjusted by fine-tuning.Then train the model to obtain experimental results. The experimental results show that our method has excellent recognition performance in the recognition of new coronary pneumonia images,even with only a small number of CT image samples.
Predictors of COVID-19 vaccine acceptance across time and countries
Authors: Kerr John R. , Schneider Claudia R. , Recchia Gabriel , Dryhurst Sarah , Sahlin Ullrika , Dufouil Carole , Arwidson Pierre , Freeman Alexandra L. J. , van der Linden Sander
Published: December 2020

Understanding the drivers of vaccine acceptance is crucial to the success of COVID-19 mass vaccination campaigns. Across 25 national samples from 12 different countries we examined the psychological correlates of willingness to receive a COVID-19 vaccine (total N = 25,334), with a focus on risk perception and trust in a number of relevant actors, both in general and specifically regarding the COVID-19 pandemic. Male sex, trust in medical and scientific experts and worry about the virus emerge as the most consistent predictors of reported vaccine acceptance across countries. In a subset of samples we show that these effects are robust after controlling for attitudes towards vaccination in general. Our results indicate that the burden of trust largely rests on the shoulders of the scientific and medical community, with implications for how future COVID-19 vaccination information should be communicated to maximize uptake.
Infant Mental Health Prevention and Treatment: A Systematic Review Examining the Role of Homelessness
Authors: Landis Taylor D. , Hare Megan M. , Graziano Paulo A.
Published: December 2020

Purpose

Whereas many prevention and treatment programs exist for children and families, there have been no reviews specifically examining infant mental health outcomes. Furthermore, despite high rates of infants and families experiencing homelessness, little work has evaluated the effectiveness of these parenting programs in such vulnerable populations. Therefore, the purpose of this study was to a) systematically examine prevention and treatment parenting programs targeting infant mental health outcomes in infants from birth to age 2 years, b) highlight strengths and limitations of current interventions, and c) identify gaps in the existing literature to inform future mental health intervention science in areas of greatest need, specifically within the context of homelessness.

Methods

From over 15,000 publications initially identified, thirty-three prevention and treatment programs met inclusion criteria for this review. Each program was reviewed for level of scientific evidence.

Results

Of the thirty-three programs reviewed, eleven (33%) were classified as promising. An additional 18% were classified as ineffective, emerging, and effective. Lastly, only four programs (12%; Attachment and Biobehavioral Catch-Up, Parent-Child Interaction Therapy, Triple P-Positive Parenting Program, and Video-feedback Intervention Parenting Program) were classified as evidence-based based on infant mental health outcomes. Few of the identified programs have been implemented in homeless shelters, with no randomized control trials to date.

Conclusions

There is a dearth of literature examining programs targeting infant mental health. Even those programs considered evidence-based have not been thoroughly examined among families in shelter settings.
Early initiation of prophylactic anticoagulation for prevention of COVID-19 mortality: a nationwide cohort study of hospitalized patients in the United States
Authors: Rentsch Christopher T , Beckman Joshua A , Tomlinson Laurie , Gellad Walid F , Alcorn Charles , Kidwai-Khan Farah , Skanderson Melissa , Brittain Evan , King Joseph T , Ho Yuk-Lam , Eden Svetlana , Kundu Suman , Lann Michael F , Greevy Robert A , Ho P. Michael , Heidenreich Paul A , Jacobson Daniel A , Douglas Ian J , Tate Janet P , Evans Stephen JW , Atkins David , Justice Amy C , Freiberg Matthew S
Published: December 2020

Importance

Deaths among patients with coronavirus disease 2019 (COVID-19) are partially attributed to venous thromboembolism and arterial thromboses. Anticoagulants prevent thrombosis formation, possess anti-inflammatory and anti-viral properties, and may be particularly effective for treating patients with COVID-19.

Objective

To evaluate whether initiation of prophylactic anticoagulation within 24 hours of admission is associated with decreased risk of death among patients hospitalized with COVID-19.

Design

Observational cohort study.

Setting

Nationwide cohort of patients receiving care in the Department of Veterans Affairs, the largest integrated healthcare system in the United States.

Participants

All patients hospitalized with laboratory-confirmed SARS-CoV-2 infection March 1 to July 31, 2020, without a history of therapeutic anticoagulation.

Exposures

Prophylactic doses of subcutaneous heparin, low-molecular-weight heparin, or direct oral anticoagulants.

Main Outcomes and Measures

30-day mortality. Secondary outcomes: inpatient mortality and initiating therapeutic anticoagulation.

Results

Of 4,297 patients hospitalized with COVID-19, 3,627 (84.4%) received prophylactic anticoagulation within 24 hours of admission. More than 99% (n=3,600) received subcutaneous heparin or enoxaparin. We observed 622 deaths within 30 days of admission, 513 among those who received prophylactic anticoagulation. Most deaths (510/622, 82%) occurred during hospitalization. In inverse probability of treatment weighted analyses, cumulative adjusted incidence of mortality at 30 days was 14.3% (95% CI 13.1-15.5) among those receiving prophylactic anticoagulation and 18.7% (95% CI 15.1-22.9) among those who did not. Compared to patients who did not receive prophylactic anticoagulation, those who did had a 27% decreased risk for 30-day mortality (HR 0.73, 95% CI 0.66-0.81). Similar associations were found for inpatient mortality and initiating therapeutic anticoagulation. Quantitative bias analysis demonstrated that results were robust to unmeasured confounding (e-value lower 95% CI 1.77). Results persisted in a number of sensitivity analyses.

Conclusions and Relevance

Early initiation of prophylactic anticoagulation among patients hospitalized with COVID-19 was associated with a decreased risk of mortality. These findings provide strong real-world evidence to support guidelines recommending the use of prophylactic anticoagulation as initial therapy for COVID-19 patients upon hospital admission.