bluuebunny/crossref_metadata_2025 huggingface dataset:
The Neuroprotective Effect of GPR4 Inhibition through Attenuation of Caspase Mediated Apoptotic Cell Death in MPTP Induced Mouse Model of Parkinson’s Disease
Authors: Haque Md. Ezazul , Azam Shofiul , Akther Mahbuba , Cho Duk-Yeon , In Su Kim , Choi Dong-Kug
Published: April 2021

GPR4, a member of proton activated GPCRs group. Previously we have reported that GPR4 is constitutively active at physiological pH and knockout of GPR4 has shown to protect dopaminergic neuronal cells from caspase-dependent mitochondrial apoptotic cell death. In this study we have investigated the role of GPR4 in 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP) treated mice model of Parkinson’s disease. Subchronic administration of MPTP in mice produces oxidative stress induced apoptotic cell death of dopaminergic neurons in the substantia nigra pars compacta (SNpc) and motor deficits. Treatment with NE52-QQ57, a selective antagonist of GPR4 reduced dopaminergic neuronal loss MPTP-intoxicated C57BL6/J mice and improved motor deficit and memory impairment. Co-treatment with NE52-QQ57 significantly decreases the protein level of proapoptotic marker (Bax), and increases the antiapoptotic marker (Bcl-2) in the SNpc and striatum tissue collected from the brain of MPTP inflicted mice. Further, MPTP induced activation of caspase 3 and cleavage of poly (ADP-ribose) polymerase (PARP) was significantly decreased in the SNpc and striatum tissue of NE52-QQ57 cotreated mice. Further mice receiving both MPTP and NE52-QQ57 mice showed significantly higher TH positive cells in the SNpc and striatum than MPTP treated mice alone. Moreover, NE52-QQ57 cotreatment improved the motor activity in the rotarod test and pole test and also improved spatial memory in Y maze test. Our findings suggest GPR4 as a potential therapeutic target for PD whereas the activation GPR4 is involved in the caspase mediated apoptotic cell death in SNpc and striatum of MPTP-intoxicated mice.
Tiltification — An Accessible App to Popularize Sonification
Authors: Asendorf Malte , Kienzle Moritz , Ringe Rachel , Ahmadi Fida , Bhowmik Debaditya , Chen Jiumeng , Huynh Kelly , Kleinert Steffen , Kruesilp Jatawan , Lee Ying Ying , Wang Xin , Luo Wei , Jadid Navid Mirzayousef , Awadin Ahmed , Raval Varun , Schade Eve Emily Sophie , Jaman Hasanur , Sharma Kashish , Weber Colin , Winkler Helena , Ziemer Tim
Published: April 2021

This paper presents Tiltification, a multi modal spirit level application for smartphones. The non-profit app was produced by students in the master project “Sonification Apps” in winter term 2020/21 at the University of Bremen. In the app, psychoacoustic sonification is used to give feedback on the device’s rotation angles in two plane dimensions, allowing users to level furniture or take perfectly horizontal photos. Tiltification supplements the market of spirit level apps with the unique feature of auditory information processing. This provides for additional benefit in comparison to a physical spirit level and for more accessibility for visu- ally and cognitively impaired people. We argue that the distribution of sonification apps through mainstream channels is a contribution to establish sonification in the market and make it better known to users outside the scientific domain. We hope that the auditory display community will support us by using and recommending the app and by providing valuable feedback on the app functionality and design, and on our communication, advertisement and distribution strategy.
Hesitancy of Arab Healthcare Workers Towards COVID-19 Vaccination: A Large-Scale Multinational Study
Authors: Qunaibi Eyad , Basheti Iman , Soudy Mohamed , Sultan Iyad
Published: April 2021

Background: Health Care Workers (HCWs) are at increased risk of acquiring and transmitting COVID-19 infection. Also, they present role models for communities with regards to attitudes towards COVID-19 vaccination. Hence, hesitancy of HCWs towards vaccination can crucially affect the efforts aiming to contain the pandemic. Previously published studies paid little attention to HCWs in Arab countries, which has a population of over 440 million. Objectives: to assess the rates of COVID-19 vaccine hesitancy in Arabic-speaking HCWs residing in and outside the Arab countries, and their perceived barriers towards vaccination. Methods: a cross-sectional study based on an online survey was conducted from 14-Jan 2021 to 29-Jan 2021, targeting Arabic-speaking HCWs from all around the world. Results: the survey recruited 5,708 eligible participants (55.6% males, 44.4% females, age 30.6±10 years) from 21 Arab countries (87.5%) and 54 other countries (12.5%). Our analysis shows a significant rate of vaccine hesitancy among Arabic-speaking HCWs residing in and outside Arab countries (25.8% and 32.8%, respectively). The highest rates of hesitancy were among participants from the west region of the Arab world (Egypt, Morocco, Tunisia, and Algeria). The most cited reasons for hesitancy were concerns about side effects and distrust in vaccine expedited production and healthcare policies. Factors associated with higher hesitancy included age of 30-59, previous or current suspected or confirmed COVID-19, female gender, not knowing the vaccine type authorized in the participant’s country, and not regularly receiving the influenza vaccine. Conclusion: this is the first large-scale, multinational, post-vaccine-availability study on COVID-19 vaccine hesitancy among HCWs. It reveals high rates of hesitancy among Arab-speaking HCWs. Unless addressed properly, this hesitancy can impede the efforts for achieving widespread vaccination and collective immunity.
Hesitancy of Arab Healthcare Workers Towards COVID-19 Vaccination: A Large-Scale Multinational Study
Authors: Qunaibi Eyad , Basheti Iman , Soudy Mohamed , Sultan Iyad
Published: April 2021

Background: Health Care Workers (HCWs) are at increased risk of acquiring and transmitting COVID-19 infection. Also, they present role models for communities with regards to attitudes towards COVID-19 vaccination. Hence, hesitancy of HCWs towards vaccination can crucially affect the efforts aiming to contain the pandemic. Previously published studies paid little attention to HCWs in Arab countries, which has a population of over 440 million. Objectives: to assess the rates of COVID-19 vaccine hesitancy in Arabic-speaking HCWs residing in and outside the Arab countries, and their perceived barriers towards vaccination. Methods: a cross-sectional study based on an online survey was conducted from 14-Jan 2021 to 29-Jan 2021, targeting Arabic-speaking HCWs from all around the world. Results: the survey recruited 5,708 eligible participants (55.6% males, 44.4% females, age 30.6±10 years) from 21 Arab countries (87.5%) and 54 other countries (12.5%). Our analysis shows a significant rate of vaccine hesitancy among Arabic-speaking HCWs residing in and outside Arab countries (25.8% and 32.8%, respectively). The highest rates of hesitancy were among participants from the west region of the Arab world (Egypt, Morocco, Tunisia, and Algeria). The most cited reasons for hesitancy were concerns about side effects and distrust in vaccine expedited production and healthcare policies. Factors associated with higher hesitancy included age of 30-59, previous or current suspected or confirmed COVID-19, female gender, not knowing the vaccine type authorized in the participant’s country, and not regularly receiving the influenza vaccine. Conclusion: this is the first large-scale, multinational, post-vaccine-availability study on COVID-19 vaccine hesitancy among HCWs. It reveals high rates of hesitancy among Arab-speaking HCWs. Unless addressed properly, this hesitancy can impede the efforts for achieving widespread vaccination and collective immunity.
Coordination Chemistry of a bis(tetrazine) tweezer: A Case of Host-guest Behavior With Silver Salts
Authors: Mboyi Cleve Dionel , Amamou Ons , Fleurat-Lessard Paul , Roger Julien , Cattey Hélène , Devillers Charles H. , Meyer Michel , Boubaker Taoufik , Hierso Jean-Cyrille
Published: April 2021

The carbon-carbon cross-coupling of phenyl s-tetrazine (Tz) units at their ortho-phenyl positions allows to form constrained bis(tetrazines) with original tweezer structures. In these compounds, the face-to-face positioning of the central tetrazine cores is endorsed by pi-staking of the electron-poor nitrogen-containing heteroaromatic moieties. The resulting tetra-aromatic structure can be used as a weak coordinating ligand with cationic silver. This coordination generates a set of bis(tetrazine)‐silver(I) coordination complexes tolerating a large variety of counter anions of various geometries, namely, PF6–, BF4–, SbF6–, ClO4–, NTf2–, OTf2–. These compounds were characterized in the solid-state by single crystal XRD and reflectance spectra, and in solution by 1H NMR, mass spectrometry, electroanalysis and UV-visible absorption spectroscopy. The X-ray diffraction (XRD) structure of complexes {[Ag(3)][PF6]}∞ (4) and {[Ag(3)][SbF6]∞ (6), where 3 is 3,3'-[(1,1'-biphenyl)-2,2'-diyl]-6,6'-bis[phenyl]-1,2,4,5-tetrazine, revealed the formation of 1D polymeric chains, characterized by an evolution to a large opening of the original tweezer and a coordination of silver(I) via two chelating nitrogen atom and some C=C pi-interactions. Electrochemical and UV spectroscopic properties of the original tweezer and of the corresponding silver complex are reported and compared. 1H NMR titrations with AgNTf2 allowed to determine the stoichiometry, and apparent stability of two solution species, namely [Ag(3)]+ and [Ag(3)2]2+, that formed in CDCl3/CD3OD 2:1 v/v mixtures.
Forensic Speaker Verification: Case Report at Brazilian Justice
Authors: Machado Thyago J. , Filho Jozue Vieira , de Oliveira Mario A.
Published: April 2021

This case report investigates 5 real cases which followed legal channels and were judged by Mato Grosso Court in Brazil. Audio systems served as elements of key evidence on those lawsuits. The goal here is to analyze the cases by using a methodology based on the forensic speaker verification by using the Ordinary Least Squares (OLS) algorithm and to compare results with analyses obtained on real cases. The comparative analysis is assessed for time elapsed for obtaining results, as well as results quality. In Brazil, the lawsuit duration is very important, since the Penal Code foresees prescription after a given time, and it may lead to impunity. Results show that the analysis, by using OLS, generates immediate, effective results when compared to those obtained with traditional methodologies on the studied Brazilian lawsuits.
Guaranted Diversity and Optimality in Cost Function Network Based Computational Protein Design Methods
Authors: Ruffini Manon , Vucinic Jelena , de Givry Simon , Katsirelos George , Barbe Sophie , Schiex Thomas
Published: April 2021

Proteins are the main active molecules of Life. While natural proteins play many roles, as enzymes or antibodies for example, there is a need to go beyond the repertoire of natural proteins to produce engineered proteins that precisely meet application requirements, in terms of function, stability, activity or other protein capacities. Computational Protein Design aims at designing new proteins from first principles, using full-atom molecular models. However, the size and complexity of proteins require approximations to make them amenable to energetic optimization queries. These approximations make the design process less reliable and a provable optimal solution may fail. In practice, expensive libraries of solutions are therefore generated and tested. In this paper, we explore the idea of generating libraries of provably diverse low energy solutions by extending Cost Function Network algorithms with dedicated automaton-based diversity constraints on a large set of realistic full protein redesign problems. We observe that it is possible to generate provably diverse libraries in reasonable time and that the produced libraries do enhance the Native Sequence Recovery, a traditional measure of design methods reliability.
Determining Levels of Biological Geometric Information at Polygonal Shape Patterns
Authors: von Bülow Philipp , Lopez-Sauceda Juan , Carrillo-Gonzalez Jose Gerardo , Ortega-Laurel Carlos , Laguna-Sánchez Gerardo Abel , Sandoval-Gutierrez Jacobo , Perez-Martinez Francisco , Miranda-Perkins Kalina
Published: April 2021

Based on a measuring system to determine the statistical heterogeneity of individual polygons we propose a method to use polygonal shape patterns as a source of data in order to determine the Shannon entropy of biological organizations. In this research, the term entropy is a particular amount of data related with levels of spatial heterogeneity in a series of different geometrical meshes and sets of random polygons. We propose that this notion of entropy is important to measure levels of information in units of bits, measuring quantities of heterogeneity in geometrical systems. In fact, one important result is that binarization of heterogeneity frequencies yields a supported metric to determine geometrical information from complex configurations. Thirty-five geometric aggregates are tested; biological and non-biological, in order to obtain experimental results of their spatial heterogeneity which is verified with the Shannon entropy parameter defining low particular levels of geometrical information in biological samples. Geometrical aggregates (meshes) include a spectrum of organizations ranging from cell meshes to ecological patterns. Experimental results show that a particular range (0.08 and 0.27) of information is intrinsically associated with low rates of heterogeneity. We conclude it as an intrinsic feature of geometrical organizations in multi-scaling biological systems.
Strategic Pathways to Scale Up Forest and Landscape Restoration: Insights From Nepal’s Terai
Authors: Bhattarai Sushma , Pant Basant , Laudari Hari Krishna , Rai Rajesh Kumar , Mukul Sharif A.
Published: April 2021

Deforestation and forest degradation mostly caused by human interventions affects the capacity of forest ecosystem to provide ecosystem services and livelihood benefits. Forest Land Restoration (FLR) is an emerging concept which focuses on the improvement of ecosystem as well as livelihood of the people at the landscape level. Nepal has successfully recovered degraded forest land mainly from the hilly region through forest restoration initiatives especially community based forestry. However, the Terai region is still experiencing deforestation and forest degradation. This study navigated the gaps related to forest restoration in the existing policies and practices and revealed that the persistence of deforestation and forest degradation in Terai is a result of a complex socio-economic structure, limitation of government to implement appropriate management modality, unplanned infrastructure, and urban development. We suggest that forest restoration should focus on ecological and social wellbeing pathways at the landscape level, to reverse the trend of deforestation and forest degradation in the Terai regions of Nepal. The study provides a critical insight to the policy makers and practitioners of Nepal and other countries (with similar context) who are engaged in forest/ecosystem restoration enterprise.
ICHTHYOFAUNA IN THE INNER CONTINENTAL SHELF NEXT TO THE PARANAGUÁ ESTUARINE COMPLEX, SOUTHERN BRAZIL
Authors: SANTOS Cesar , SCHWARZ JUNIOR Roberto , PICHLER Helen Audrey , CARDOSO Olímpio Rafael , LAMOUR Marcelo Renato , SPACH Henry Louis
Published: April 2021

The composition and structure of fish assemblages in the inner continental shelf of the Paraná State are affected by cold fronts and the rainfall regime. Data from fishing activities in this region, as well as the analysis of environmental characteristics, are the main tools available for understanding fish dynamics, under influence of increasing human activities. In order to better understand patterns and temporal variations in fish assemblages in the inner continental shelf of the Paraná State, a total of 24 double trawls were performed with an otter trawl between August 2000 and July 2001, in two sampling areas, the North area in front of the northern mouth of the Paranaguá Estuary Complex, and the South area, in front of the Leste beach. A total of 45,277 fish specimens belonging to 35 families and 97 species were caught. Sciaenidae was the most abundant family, with 37.1% of the total number of individuals caught, and with the highest richness (18 species). Statistical analyses evidenced significant differences in environmental characteristics and in fish fauna, and that both areas disturbances were observed in the fish assemblages during the dry and wet season, being more intense in the Southern area, disturbances that would be related to the shrimp fishing present in the two areas sampled in this study.
PROTOTIPE PORTAL KOMPLEK PERUMAHAN DENGAN SISTEM RFID (Radio Frequency Identification) BERBASIS ARDUINO MEGA 2560
Authors: Candra S Ben , Sunawar Aris , Hanifah Y Nur
Published: April 2021

Abstract

Issue in this paper is to explain about the making of "The Prototype of portal housing with RFID-based system arduino Mega 2560". Recently, many cases of theft and robbery in housing, especially in the elite residential State, which is due to a weak security system and there is no limit access to people in entering a residential State environment.In this thesis, the author intends to answer questions and provide solutions on the weakness of the security system and the restrictions in the access using RFID card that serves to open access doorstop contained in post enters into a residential state. The method used in this paper is a method book study and discussion by collecting the information by finding references related to the research conducted. In this prototype Arduino Mega 2560 is a control device used for this prototype system, because the Arduino Mega 2560 has a number of inputs and outputs and having an Ethernet port to facilitate for the settings. This prototype so is suitable implementation of her for use in residential complexes and commercial resident, as it helps in running the security system where every vehicle that does not have access cards (RFID Card) / registered in the database, cannot enter into a residential housing that implement this prototype.

 

Abstrak

Pokok pembahasan dalam skripsi ini adalah menjelaskan tentang pembuatan “prototype portal komplek perumahan dengan sistem RFID berbasis arduino mega 2560”. Belakangan ini banyak terjadi kasus pencurian dan perampokan pada perumahan, terutama di lingkungan kompleks perumahan elit, yang dikarenakan lemahnya system keamanan dan tidak ada batasan akses orang dalam memasuki sebuah lingkungan komplek perumahan. Pada skripsi ini penulis bermaksud untuk menjawab pertanyaan dan memberikan solusi tentang lemahnya system keamanan dan pembatasan orang dalam akses masuk dengan menggunakan kartu RFID yang berfungsi untuk akses membuka palang pintu yang terdapat di pos masuk dalam sebuah komplek perumahan. Metode yang digunakan penulis dalam penulisan skripsi ini adalah metode studi pustaka dan diskusi dengan melakukan pengumpulan informasi yang dilakukan dengan mencari referensi-referensi yang berhubungan dengan penelitian yang dilakukan. Pada prototype ini Arduino Mega 2560 adalah perangkat kendali yang dipakai untuk system prototype ini, karena Arduino Mega 2560 memiliki jumlah input dan output yang banyak dan mempunyai port Ethernet sehingga memudah kan dalam pengaturannya.Prototipe ini sangat lah cocok implementasi nya untuk digunakan pada kompleks perumahan maupun niaga perkomplekan, karena membantu dalam menjalankan system keamanan dimana setiap kendaraan yang tidak mempunyai access card (RFID Card)/ terdaftar dalam database, tidak dapat masuk kedalam kompleks perumahan yang mengimplementasikan prototype ini.

database, tidak dapat masuk kedalam kompleks perumahan yang mengimplementasikan prototype ini.
Deformation–sedimentation feedback and the development of anomalously thick aggradational turbidite lobes: Outcrop and subsurface examples from the Hikurangi Margin, New Zealand
Authors: McArthur Adam D. , Bailleul Julien , Mahieux Geoffroy , Claussmann Barbara , Wunderlich Alex , McCaffrey William D.
Published: April 2021

Concepts of the interaction between autogenic (e.g., flow process) and allogenic (e.g., tectonics) controls on sedimentation have advanced to a state that allows the controlling forces to be distinguished. Here we examine outcropping and subsurface Neogene deep-marine clastic systems that traversed the Hikurangi subduction margin via thrust-bounded trench-slope basins, providing an opportunity to examine the interplay of structural deformation and deep-marine sedimentation. Sedimentary logging and mapping of Miocene outcrops from the exhumed portion of the subduction wedge record heavily amalgamated, sand-rich lobe complexes, up to 200 m thick, which accumulated behind NE–SW-oriented growth structures. There was no significant deposition from low-density parts of the gravity flows in the basin center, although lateral fringes demonstrate fining and thinning indicative of deposits from low-density flows. Seismic data from the offshore portion of the margin show analogous lobate reflector geometries. These deposits accumulate into complexes up to 5 km wide, 8 km long, and 300 m thick, comparable in scale with the outcropping lobes on this margin. Mapping reveals lobe complexes that are vertically stacked behind thrusts. These results illustrate repeated trapping of the sandier parts of turbidity currents to form aggradational lobe complexes, with the finer-grained suspended load bypassing to areas downstream. However, the repeated development of lobes characterized by partial bypass implies that a feedback mechanism operates to perpetuate a partial confinement condition, via rejuvenation of accommodation. The mechanism proposed is a coupling of sediment loading and deformation rate, such that load-driven subsidence focuses stress on basin-bounding faults and perpetuates generation of accommodation in the basin, hence modulating tectonic forcing. Recognition of such a mechanism has implications for understanding the tectono-stratigraphic evolution of deep-marine fold and thrust belts and the distribution of resources within them.
Use of Trained Non-Medical Staff to Improve Access to HIV Testing Services in Africa: Implementation of the World Health Organization Opt-out Approach in Cameroon
Authors: Kouanfack Charles , Lekelem Skinner , Bede Fala , Nkfusai Ngwayu Claude , Nouafo Yvette , Tchokonte Christian , Zephirin Nicaise , Fouda Pierre Joseph
Published: April 2021

Background: The Joint United Nations Programme on HIV/AIDS (UNAIDS) in 2019 estimated that 450,000 to 50,000 people in Cameroon were living with HIV, yet only 79% knew their HIV status which is far from the 90% target for 2020. To address this situation, Cameroon adopted the “Opt-out” strategyof the World Health Organization (WHO) and use of trained non-medical cadre (psychosocial agents) to reach out to more people with HIV testing services (HTS). This describes the implementation and outcomes of this strategy by reviewing the activity of a typical day in the Yaoundé Central Hospital (YCH) in Cameroon.
Methods: HTS were offered to hospitalized and ambulatory patients (including their companions) in different departments of the YCH. Following screening for recent HIV testing, those with unknown HIV status that gave consent or did not explicitly refuse testing (as per the “Opt-out Strategy”), were counseled and tested for HIV. Testing followed the “National HIV Rapid Testing Algorithm” using rapid diagnostic test kits. Results were either positive, negative or indeterminate. Patients with positive HIV results were linked to the Care and Treatment Center for treatment initiation.
Results: Of the 350 patients screened and offered HTS using non-medical cadre (psychosocial agents), 193 (55.1%) were hospitalized and 157 (44.9%) came for outpatient visits. The age of participants ranged from 14 to 92 years and the yield of HIV testing in the sample population was 5.1% (6.2% for hospitalized patients and 3.8% for outpatient clinics). Statistics revealed that five HIV-positive patients had never been offered HTS before the study. The study revealed that HTS acceptance rate among hospitalized patients was 69.6% and that all new positive patients started antiretroviral treatment on the same day.
Conclusion and Global Health Implications: It is feasible to use trained non-medical staff for HIV testing services (HTS). Task-shifting by using trained psychosocial agents can help in case identification and linkage to HIV treatment services.
 
Copyright © 2021 Kouanfack et al. Published by Global Health and Education Projects, Inc. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work, first published in this journal, is properly cited.
Justification on Choosing Screw Pumping Units as Energy Efficient Artificial Lift Technology
Authors: Sidorkin D. I. , Kupavykh K. S.
Published: April 2021

The paper analyzes the main techniques and technologies of oil fluid recovery in the context of energy consumption, significantly rising over the latest decade. It is recognized that the number of publications in the area of energy efficiency is growing steadily. Currently Russian oil and gas industry are facing the task of accelerating reduction of energy consumption while preserving, or even increasing, production rates. The task is complicated by the fact that the majority of deposits in Russia either have already entered (primarily, Volga-Ural region) or are now entering (West Siberia) their last stage of exploration, whereas new deposits in East Siberia are only being brought into production. Furthermore, a lot of new deposits, which provide for high recovery rates, are profitable a priori as at the first stage of exploration they do not need any artificial lift due to their free flow production without any oil well pumps. However, there is a significant share of new deposits with low-permeability reservoirs, which require either a system of reservoir pressure maintenance or periodic hydraulic fracturing. At the same time deposits at the late stages of exploration, apart from the use of pump units, systems of reservoir pressure maintenance and hydraulic fracturing, require regular repair and restoration, measures against salt and heavy oil sediments, mechanical impurities, flooding, etc., which all has a negative effect on well profitability. In order to solve these problems, the authors review existing methods and calculate specific energy consumption using various pump systems for hypothetical wells, varying in yield. According to the research results, it has been revealed that from the point of view of energy efficiency, it is desirable to equip low- and low-yield wells with sucker rod progressive cavity pump units, medium-yield ones – with electric progressive cavity pumps driven by permanent magnet motor, medium- and high-yield wells – with electric progressive cavity pumps or electric submersible pumps driven by permanent magnet motor, depending on the characteristics of the pumpedout oil fluid.
Approximate Solution of Mixed Problem for Telegrapher Equation with Homogeneous Boundary Conditions of First Kind Using Special Functions
Authors: Lasy P. G. , Meleshko I. N.
Published: April 2021

The mixed problem for the telegraph equation well-known in electrical engineering and electronics, provided that the line is free from distortions, is reduced to a similar problem for one-dimensional inhomogeneous wave equation. An effective way to solve this problem is based on the use of special functions – polylogarithms, which are complex power series with power coefficients, converging in the unit circle. The exact solution of the problem is expressed in integral form in terms of the imaginary part of the first-order polylogarithm on the unit circle, and the approximate one – in the form of a finite sum in terms of the real part of the dilogarithm and the imaginary part of the third-order polylogarithm. All the indicated parts of the polylogarithms are periodic functions that have polynomial expressions of the corresponding degrees on an interval of length in the period, which makes it possible to obtain a solution to the problem in elementary functions. In the paper, we study a mixed problem for the telegrapher’s equation which is well-known in applications. This problem of linear substitution of the desired function witha time-exponential coefficient is reduced to a similar problem for the Klein – Gordon equation. The solution of the latter can be found by dividing the variables in the form of a series of trigonometric functions of a line point with time-dependent coefficients. Such a solution is of little use for practical application, since it requires the calculation of a large number of coefficients-integrals and it is difficult to estimate the error of calculations. In the present paper, we propose another way to solve this problem, based on the use of special He-functions, which are complex power series of a certain type that converge in the unit circle. The exact solution of the problem is presented in integral form in terms of second-order He-functions on the unit circle. The approximate solution is expressed in the final form in terms of third-order He-functions. The paper also proposes a simple and effective estimate of the error of the approximate solution of the problem. It is linear in relation to the line splitting step with a time-exponential coefficient. An example of solving the problem for the Klein – Gordon equation in the way that has been developed is given, and the graphs of exact and approximate solutions are constructed.
On Fulfillment of Energy Conservation Law in Theory of Elastic Waves V. V. Nevdakh1)
Authors: Nevdakh V. V.
Published: April 2021

In accordance with the energy conservation law, the total energy of a closed physical system must remain constant at any moment of time. The energy of a traveling elastic wave consists of the kinetic energy in the oscillating particles of the medium and the potential energy of  its elastic deformation. In the existing theory of elastic waves, it is believed that the kinetic and potential energy densities of a traveling wave without losses  are the same at any moment of time and vary according to the same law. Accordingly, the total energy density of such wave is different at various moment of time, and only its time-averaged value remains constant. Thus, in the existing theory of elastic waves, the energy conservation law is not fulfilled. The purpose of this work is to give a physically correct description of these waves. A new description of a sound wave in an ideal gas has been proposed and it is based on the use of a wave equation system for perturbing the oscillation velocity of gas particles, which determines their kinetic energy, and for elastic deformation, which determines their potential energy. It has been shown that harmonic solutions describing the oscillations of the gas particles velocity perturbation and their elastic deformation, which are phase shifted by p/2, are considered as physically correct solutions of such equations system for a traveling sound wave. It has been found that the positions of the kinetic and potential energy maxima in the elastic wave, described by such solutions, alternate in space every quarter of the wavelength. It has been established that every quarter of a period in a wave without losses, the kinetic energy is completely converted to potential and vice versa, while at each spatial point of the wave its total energy density is the same at any time, which is consistent with the energy conservation law. The energy flux density of such traveling elastic wave is described by the expression for the Umov vector. It has been concluded that such traveling sound wave without losses  in an ideal gas can be considered as a harmonic oscillator.
Coupling Peridynamics with the Classical Methods for Modeling Hydraulic Fracture Growth in Heterogeneous Reservoirs
Authors: Agrawal Shivam , York Jason , Foster John T. , Sharma Mukul M.
Published: April 2021

Hydraulic fracture (HF) modeling is a multiscale and multiphysics problem. It should capture various effects, including those of in-situ stresses, poroelasticity, and reservoir heterogeneities at different length scales. A peridynamics (PD)-based hydraulic fracturing simulator has been demonstrated to reproduce this physics accurately. However, accounting for such details leads to a reduction in computational speed. In this paper, we present a novel coupling of the PD-based simulator with numerically efficient finite element methods (FEMs) and finite volume methods (FVMs) to achieve a significant improvement in computational performance.

Unlike classical methods, such as FEM and FVM that solve differential equations, PD uses an integral formulation to circumvent the undefined spatial derivatives at crack tips. We implemented four novel coupling schemes of our PD-based simulator with FEM and FVM: static PD region scheme, dynamic PD region scheme, adaptive mesh refinement scheme, and dynamic mesh coarsening scheme. PD equations are solved using a refined mesh close to the fracture, whereas FE/FV equations are solved using a progressively coarser mesh away from the fracture. As the fracture grows, a dynamic conversion of FE/FV cells to PD nodes and adaptive mesh refinement are incorporated. To improve the performance further, the dynamic mesh coarsening scheme additionally converts the fine PD nodes back to coarse FE/FV cells as the HF grows in length.

The coupling schemes are verified against the Kristianovich-Geertsma-de Klerk (KGD) fracture propagation problem. No spurious behavior is observed near the transition between PD and FE/FV regions. In the first three coupling schemes, the computational runtime for single fracture propagation is reduced by up to 10, 20, and 50 times, respectively, compared to a pure PD model.

Laboratory experiments on the interaction of an HF with a natural fracture (NF) are revisited. The model captures complex fracture behavior, such as turning in the case of low stress contrast and low angle of interaction, kinking for higher stress contrast or higher angle of interaction, and fracture crossing for near-orthogonal NFs. Moreover, several previously reported phenomena, including fracture propagation at an angle to the principal stress directions, competing fracture growth from multiple closely spaced clusters, and interaction with layers of varying mechanical properties are successfully modeled.

Thus, the coupling of PD with FEM and FVM offers an innovative and fundamentally comprehensive solution to alleviate the high computational costs typically associated with the pure PD-based hydraulic fracturing simulations. At the same time, these coupling schemes retain the versatility of the nonlocal PD formulation at modeling the evolution of arbitrary material damage, commonly observed during HF propagation in complex heterogeneous reservoirs.
Selective scandium ion capture via coordination templating in a covalent organic framework
Authors: Yuan Ye , Yang Yajie , Meihaus Katie R. , Zhang Shenli , Ge Xin , Zhang Wei , Faller Roland , Long Jeffrey , Zhu Guangshan
Published: April 2021

The use of coordination complexes as building units within covalent organic frameworks (COFs) has significant potential to diversify the structures and properties of this class of materials. Here, we present a synergistic coordination and reticular chemistry approach to the design of a series of crystalline scandium–covalent organic frameworks (Sc–COFs), featuring tunable levels of metal incorporation. Removal of scandium from the material with the highest metal content results in a metal-imprinted COF (MICOF) that exhibits high affinity and capacity for Sc3+ ions in acidic environments and in the presence of competing metal ions. In particular, the selectivity of this MICOF for Sc3+ over common impurity ions such as La3+ and Fe3+ surpasses that of all reported scandium adsorbents. Importantly, analogous materials can be prepared starting from earth-abundant transition metals, highlighting the versatility of this approach for the development of tailor-made metal–COFs and MICOFs for applications involving selective metal ion capture.
Spinal Cord Injury and Spinal Fracture in Patients with Ankylosing Spondylitis
Authors: Tu Po-Hsun , Liu Zhuo-Hao , Yeap Mun-Chun , Liu Yu-Tse , Li Ying-Ching , Huang Yin-Cheng , Lin Tzu-Min , Chen Ching-Chang
Published: April 2021

Background: Spinal cord injury (SCI) and spinal fracture are major complications in patients with ankylosing spondylitis (AS) who sustain spinal trauma. The purpose of this study is to investigate the incidence, predictors, and sequelae of spinal trauma in patients with AS.Methods: This study evaluated our AS patients who had spinal traumas between January 1, 2006, and June 30, 2016 and a comparison of those patients with SCI alone, fracture alone and both SCI and spinal fracture.Results: 105 patients were enrolled. Of these patients, 89.5% had spinal fractures, and 57.1% had SCI. Among the patients with spinal fractures, 52.1% had SCI. The existence of bamboo spine was significantly more frequent in the fracture group (78.7% vs. 36.4%; P = 0.006) than in the non-fracture group. The SCI patients had more subluxation or dislocation (48.3% vs. 8.9%; P <0.001), and more cases of spinal epidural hematoma (SEH) (21.7% vs. 2.2%; P = 0.003) than the non-SCI patients. The rate of delayed diagnosis for spinal fracture was 31.4%, where 1/3 of these patients developed delayed SCI. Among the incomplete SCI patients, 58.3% had neurological improvement after treatment (P = 0.004). Conclusions: The patients with existing bamboo spine at X-ray had a higher spinal fracture rate. Spinal fractures involving the C3-C7 region, subluxation or dislocation, spinal fracture severity, and a SEH were found to be predictive of SCI. SCI in AS patients resulted in a high mortality and complication rates.
The fault re-decision method based on the different decreasing functions
Authors: Cui Jianyuan , Ren Bin , Li Gang , Jia Zhi-Xin
Published: April 2021

The fault diagnosis method (FDM) is widely used in machine operation and maintenance. However, the wrong decision made by the FDM might cause the machine unnecessarily to shut down. To reduce the number of false alarms, this paper proposes a fault re-decision method based on the key-delay technology. The original data from sensors are inputted into the inner fault diagnosis method (IFDM) and the proposed method only employs the results from the IFDM as the input. Then according to the improved key-delay technology and comprehensive consideration of current result and previous results, the re-decision is given. To illustrate the proposed method, a case study on gear is presented in this paper, which shows that the proposed method does decrease the false negative rate.
​Point-of-Care Ultrasound (POCUS) practices in the Helicopter Emergency Medical Services in Europe
Authors: Hilbert-Carius Peter , Struck Manuel F , Rudolph Marcus , Knapp Jürgen , Rognås Leif , Adler Jürgen , Slagt Cor , Jacobsen Lars , Pich Henryk , Christian Michael D , Dandrifosse Didier , Abu-Zidan Fikri
Published: April 2021

Background: The extent to which Point-of-care of ultrasound (POCUS) is used in different European helicopter EMS (HEMS) is unknown. We aimed to study the availability, perception, and future aspects of POCUS in the European HEMS. Methods: A survey about the use of POCUS in HEMS was conducted by a multinational steering expert committee and was carried out from November 30, 2020 to December 30, 2020 via an online web portal. Invitations for participation were sent via email to the medical directors of the European HEMS organizations including two reminders. Results: During the study period, 69 participants from 25 countries and 41 different HEMS providers took part in the survey. 96% (n=66) completed the survey. POCUS was available in 75% of the responding HEMS organizations when needed (56% always, and 19% occasionally). 17% were planning to establish POCUS in the near future. Responders who provided POCUS used it in approximately 15% of the patients. Participants thought that POCUS is important in both trauma and non-trauma-patients (73%, n=46). The extended focused assessment sonography for trauma (eFAST) protocol (77%) was the most common used protocol. A POCUS credentialing process including documented examinations was requested in less than one third of the HEMS organizations.Conclusions: The majority of the HEMS organizations in Europe are able to provide different POCUS protocols in their services. The most used POCUS protocols were eFAST, FATE and RUSH. Despite the enthusiasm for POCUS, comprehensive training and clear credentialing processes are lacking in about two thirds of the European HEMS organizations.
Stable 3D seam tracking for thick plate GMAW manufacturing with T-joints using Kalman filter and machine learning
Authors: He Yinshui , Yu Zhuohua , Xiao Ziyi , Le Jian
Published: April 2021

In this paper, a robust stable three-dimensional (3D) seam tracking method is investigate based on the Kalman filter (KF) and machine learning during the multipass gas metal arc welding process with a T-joint of 60 mm thickness. The laser vision sensor is used to profile the weld seam, and with the reference image captured before arcing a scheme is proposed to extract the variable weld seam profiles (WSPs) using scale-invariant feature transform and the clustering algorithm. An effective slope mutation detection method is presented to identify the feature points of the extracted WSP, namely the candidate welding positions. In order to lower the impact of fake welding positions on seam tracking, a Bayesian Network model is first built to implement fault detection and diagnosis for the visual feature measurement process using the involved process parameters and the trigger rule. A KF, as an estimator, is then established to further stabilize the tracking process combing with a self determination algorithm of the measurement result. With the visual calibration technology, 3D seam tracking is realized. Seam tracking results show that the proposed method overcomes the tremor of the tracking position and multiple fake candidate welding positions on tracking accuracy, and the tracking accuracy is 0.6 mm. This method provides potential industrial application value for industrial manufacturing with large-scale components.
Highly anisotropic resonant dynamics in the aligned-aligned scattering of cold diatoms
Authors: Zhou Haowen , Perreault William , Mukherjee Nandini , Zare Richard
Published: April 2021

The dynamics of a resonant oriented scattering process dominated by a single partial wave provide the most sensitive probe of the long-range anisotropic forces important to chemical reactions. Here, we control the collision temperature and geometry to probe the dynamics of the cold (<2 K) rotationally inelastic scattering of a pair of optically state-prepared D2 molecules. The collision temperature is manipulated by combining the strobing action of laser state preparation and detection with the velocity dispersion of the molecular beam. When the bond axes are aligned parallel to the collision velocity, the scattering rate drops by nearly an order of magnitude when collision energies >1 K are removed, demonstrating a clear geometry-dependent resonance. Using partial wave analysis of the measured scattering angular distribution, we determine that an l = 2 shape resonance originates from the collisions between a pair of aligned D2 molecules. Our experiment illustrates the strong anisotropy of the long-range quadrupole-quadrupole interaction that controls the dynamic resonance for diatom-diatom collisions.
Determinants of Hyperemesis Gravidarum Among Pregnant Women in Public Hospitals of Mekelle City, North Ethiopia, 2019: Unmatched Case-Control Study
Authors: Tefera Zenebe , Assefaw Mandefro , W/Selassie Mulugeta
Published: April 2021

Background: Globally, hyperemesis gravidarum affects 0.3 to 3.6% of pregnant women. The etiology of hyperemesis gravidarum is unclear. In Ethiopia, limited studies have been conducted on the determinants of hyperemesis gravidarum. Therefore this study is aim to identify the determinants of hyperemesis gravidarum among pregnant women in public hospitals of Mekelle city, North Ethiopia. Methods: An unmatched case-control study was conducted from May to October 2019, with the ratio of 1:2(109 cases and 218 controls). Cases were women with hyperemesis gravidarum and controls were women who had no hyperemesis gravidarum. Cases were enrolled using consecutive sampling techniques and controls were selected by a systematic random sampling technique. Data were collected by interview using a structured questionnaire and analyzed using SPSS version 22. Statistical significance was considered at p- 0.05, and the strength of association was assessed by odds ratio and 95% confidence intervals. Result: Being housewife (AOR=2.43; 95% CI; 1.27, 4.62), unplanned pregnancy (AOR=2.58; 95% CI; 1.27, 5.24), had family history of hyperemesis gravidarum (AOR=3.85; 95% CI; 1.69, 8.75). H. pylori infection (AOR=3.50; 95% CI; 1.92, 6.39), high perceived stress (AOR=7.01; 95% CI; 2.56, 19.18) and being in the first and second trimester (AOR=6.01; 95% CI; 1.87, 19.26), and (AOR=4.73; 95% CI; 1.59, 14.00) were determinant of hyperemesis gravidarum. Conclusion and Recommendations: In this study; being a housewife, unplanned pregnancy, had a family history of hyperemesis gravidarum, H. pylori infection, high perceived stress, and being in the 1st and 2nd trimester of pregnancy were found to be the determinants of hyperemesis gravidarum. We recommend stress should be minimized through psychological support during follow up of pregnancy. Screening for H. Pylori should be taken as routine investigations for pregnant women who complain of nausea and vomiting.
A Bayesian Approach to Estimate Weights for GMPE Models in a Logic Tree
Authors: Bo Saran Srikanth , Keller Merlin , Gupta Abhinav , Senfaute Gloria
Published: April 2021

In current practice, the seismic hazard curves are generated by combining all possible choices for seismotectonic model (SM), earthquake magnitude recurrence models, and ground motion prediction equation (GMPE) models using logic trees. However, studies have shown that significant uncertainties exist in the evaluation of the seismic hazard, especially in low-to-moderate seismicity regions, such as Central \& Eastern United States and Europe, due to the scarcity of the recorded earthquake data and lack of precise knowledge concerning the earthquake generation and propagation mechanisms. Specifically, these uncertainties lead to conservatisms in the seismic hazard which poses a considerable risk for nuclear facilities. Designing or upgrading facilities with such conservative estimates of seismic hazard results in large capital costs. In standard probabilistic seismic hazard assessment (PSHA) practices, the estimate of branch weights for the GMPE models is based on expert judgment and there is no holistic approach for estimating the weights under uncertainty. In this research, we focus on the GMPE part of the PSHA and we propose a statistical methodology that is based on Bayesian inference, to evaluate the GMPE model weights from a list of GMPE models in the logic tree. In this study, Bayesian model averaging (BMA) approach with Bayesian linear models (BLM) is employed to combine GMPE models and the performance of the BMA model is tested against European Strong-Motion (ESM) database. It is shown that the proposed methodology can calculate the weights at different time periods without any approximations using analytical formulas and it is computationally inexpensive.
Polycationic Silver Nanoclusters Comprising Nanoreservoirs of Ag+-Ions with High Antimicrobial and Antibiofilm Activity
Authors: Haidari Hanif , Bright Richard , Kopecki Zlatko , Zilm Peter , Garg Sanjay , Cowin Allison , Vasilev Krasimir , Goswami Nirmal
Published: April 2021

The authors have requested that this preprint be removed from Research Square.