bluuebunny/crossref_metadata_2025 huggingface dataset:
Os movimentos estudantis na América Latina [Ruy Mauro Marini]
Authors: Jamount Jonathan Henri Sebastião
Published: March 2021

O presente artigo, datado de julho de 1969, foi publicado em francês no ano de 1970 pela revista Les temps modernes (n° 291, p. 718-731). Fundada em 1945 por Jean-Paul Sartre e Simone de Beauvoir, Les temps modernes segue sendo editada até os dias atuais, sob a direção de Claude Lanzmann. Originalmente escrito em espanhol, o texto também foi reproduzido, naquele mesmo ano, na Revista Rocinante, editada entre 1968 e 1971 em Caracas, Venezuela; o número desta revista em que foi publicado o artigo de Marini, no entanto, não consta na Biblioteca Nacional da Venezuela e é de impossível acesso no Brasil. Posteriormente, o artigo foi reproduzido em diferentes revistas da América Latina: em 1972, em Cuadernos Universitarios, revista de Ciências Sociais da Universidad Autónoma de Santo Domingo – primeira universidade da América Latina – e, mais recentemente, em 1997, na revista do Centro de Estudios Miguel Enríquez, no Chile. É ilustrativo o fato de que, para a presente reprodução, foi mais fácil ter acesso à versão francesa de Temps Modernes do que qualquer outra publicada na América Latina.Para esta tradução, além da versão francesa, o texto foi cotejado ao artigo em espanhol publicado em 1970 na revista Ciencia Social do Instituto Central de Sociologia da Universidade de Concepción, no Chile, que se encontra disponível em: http://marini-escritos.unam.mx/pdf/038_movimientos_estudiantiles.pdf. Optamos por incluir os subtítulos presentes na versão em espanhol acima destacada e ausentes na versão francesa. Por fim, é preciso sinalizar as valiosas contribuições de Fernando Corrêa Prado e do Comitê Editorial dos Cadernos Cemarx que, através de revisõescriteriosas, colaboraram para uma melhor tradução.
“A martelada da revolução”
Authors: Lemos Patrícia Rocha , Areco Sabrina
Published: March 2021

Este texto foi apresentado originalmente como intervenção de Michael Löwy na conferência organizada pela Société internationale Rosa Luxemburg realizada em 2013 na cidade de Paris. Foi publicado, em setembro de 2016, na revista Agone 59 – Révolution et démocratie. Actualité de Rosa Luxemburg [Revolução e democracia. Atualidade de Rosa Luxemburgo], sob o título de “Le coup de marteau de la révolution”: La critique de la démocratie bourgeoise chez Rosa Luxemburg. A publicação do número especial da revista e o evento dedicado à Rosa inserem-se no conjunto de atividades vinculadas ao trabalho, ainda em andamento, de publicação de suas obras completas na França pelas edições Agone e o coletivo Smolny. A tradução e a apresentação deste artigo aos Cadernos Cemarx foram motivadas pelo significativo movimento de difusão das obras de Rosa Luxemburgo nos últimos anos no Brasil e pelo crescente debate em torno de suas ideias. O autor Michael Löwy é conhecido do público marxista e seu texto chega a nós em momento bastante pertinente em que a questão da democracia está no centro do debate político do país.
Gostaríamos de agradecer imensamente a Michael Löwy, por autorizar a publicação traduzida de seu texto. Esclarecemos que as palavras destacadas em negrito ou itálico foram reproduzidas exatamente como o original enviado pelo autor. Aos livros citados no original adicionamos a referência da edição brasileira para aquelas que encontramos traduzidas. As notas da tradução foram identificadas como N. T. Esperamos que as reflexões aqui postas possam contribuir para revisitarmos as ideias de Rosa tanto como um corpo teórico, por muito tempo secundarizado pelos estudiosos marxistas, como também enquanto estímulo para repensar os limites e possibilidades da democracia burguesa e os caminhos necessários para a transformação da nossa sociedade.
Apresentação
Authors: Redação Conselho de
Published: March 2021

Com a publicação, em dois volumes, do número 2 dos Cadernos Cemarx, disponibilizamosao público as comunicações apresentadas no 3º Colóquio Marx e Engels,evento organizado em 2003 pelo Cemarx – Centro de Estudos Marxistas – da UniversidadeEstadual de Campinas – Unicamp.Esse Colóquio, intitulado Marxismo e socialismo no século XXI, elegeu como objetivoanalisar as condições de luta e os desafios a serem enfrentados pelo socialismo hoje,buscando abordar as seguintes questões:1. A situação do movimento socialista do século XX (experiências revolucionárias,partidos, sindicatos, programa);2. A reconstrução do movimento socialista diante das condições materiais do capitalismocontemporâneo;3. Os desafios ideológicos e organizativos do movimento socialista no século XXI;4. A contribuição do marxismo para a reorganização e a renovação do movimentosocialista no século XXI;5. A questão da transição ao socialismo hoje.
Tecnologias para a colaboração
Authors: Matta Alfredo Eurico Rodrigues
Published: March 2021

O trabalho versa sobre As (novas?) forças produtivas do capitalismo e trata deestudar em caráter teórico as abordagens capazes de analisar e exercitar a compreensãodos avanços da sociedade informatizada de nosso tempo. De fato, o texto se refereà emergência e implantação das tecnologias da informação e comunicação (TIC), ouseja, ao campo da interpretação das recentes inovações tecnológicas advindas do avançoda computação e de suas aplicações.
Financeirização global e Estados Nacionais
Authors: Souza Angelita Matos
Published: March 2021

Nossa exposição organizar-se-á em torno de três temas: 1. as transformações docapitalismo contemporâneo: a financeirização global; 2. o debate sobre o futuro dos Estadosnacionais diante de tais transformações; 3. Imperialismo e Estados nacionais.
Formação em tempos de diminuição da taxa de uso da mercadoria força de trabalho
Authors: Rodrigues Daniel Alvares
Published: March 2021

O presente trabalho é um ensaio sobre as exigências hegemônicas constitutivas daidéia de formação dos trabalhadores, a partir do conceito da diminuição da taxa de usodas mercadorias, utilizado por Mészáros. Este trabalho levanta o desafio de uma definiçãometodológica para o estudo, pois entende que este fenômeno está subalternoàs relações sociais produtivas capitalistas. Portanto, esse fenômeno não deve ser vistoem si, mas dentro do desenvolvimento histórico das lutas de classe.
A panacéia tecnológica e a perspectiva do valor de uso
Authors: Moura Mauro Castelo Branco de
Published: March 2021

A modernidade, sobretudo em seu apogeu iluminista, ensejou a crença numdevir auspicioso fundado, segundo Adam Smith, no desenvolvimento das forçasprodutivas do trabalho [productive powers of labour]. Porém, ainda no séculoXVIII, em meio a um otimismo generalizado, que se consagrou com a gêneseda historicidade (entendida como “progresso”) e espraiou-se através de autorescomo Kant ou Condorcet, já se insurgia Rousseau contra a crença datécnica como panacéia para a resolução dos problemas humanos. À esteira deambos (Smith e Rousseau), Marx demonstra que o capital é um poderoso estimulanteao desenvolvimento das forças produtivas, mas traz aparelhado em si asubmissão estranhada do processo de reprodução social à valorização do valor[Verwertungs des Werts], com o quinhão de barbárie que lhe é inerente. O crescimentopermanente e ilimitado da riqueza abstrata que carateriza o capital, figuraapoteótica da tríade fetichóide (mercadoria, dinheiro e capital), só se podeconsumar às expensas da subordinação da satisfação das necessidades (e davida) humanas a seu desiderato, pela imposição de seu automatismo, que subalternizatodas as apetências.
O procedimento metódico marxista no campo das ciências sociais
Authors: Felismino Sandra Cordeiro
Published: March 2021

Nesta comunicação pretendemos discutir o significado do procedimento metódicomarxista enquanto o modo de exposição das múltiplas determinações da realidadehumano-social que não são apreendidas pelas investigações de cunho positivista efenomenológico, pois estas não ultrapassam à imediatez dos processos sociais e dasinstituições, além de considerarem a objetividade dada como o fundamento ontológicodo pensamento científico.
Socialismo ou cidadania planetária? Os paradigmas educacionais dominantes e a crítica marxista
Authors: Jimenez Susana Vasconcelos
Published: March 2021

Essa comunicação refere-se a uma pesquisa voltada para o exame das principaisteorizações que têm dominado o cenário pedagógico, sob o crivo da propalada crisedos paradigmas das ciências sociais.
Resistências e adaptações à precarização do trabalho docente na UFU
Authors: Teixeira Karla Viana
Published: March 2021

Este estudo pretende investigar - a partir da crise instalada no sistema capitalista ede sua resposta, a mundialização do capital - as mudanças, objetivas e subjetivas,ocorridas nas condições do trabalho docente. O universo de investigação empíricaconsiste nos docentes da Universidade Federal de Uberlândia (UFU) que, apesar dasparticularidades, apresentam características muito similares, no referente às condiçõesde trabalho, aos demais professores do ensino superior público do Brasil.
A teoria crítica de habermas frente à perspectiva onto-prática de Marx
Authors: Vieira Zaira Rodrigues
Published: March 2021

O presente texto busca suscitar os pontos centrais de divergência do Habermas de fins da década de 60 até metade da década de 70 com Marx no que diz respeito às estruturas de dominação social e à emancipação humana objetivada por cada um deles. A teoria social de Habermas volta-se, já neste período, de forma decisiva para o campo da ‘prática’ – entendido como sen-do o campo da formação da vontade e das tomadas de decisões pela intera-ção comunicativa.
A inserção de classe dos assalariados não-manuais
Authors: Trópia Patrícia Vieira
Published: March 2021

Uma das polêmicas que tem motivado a teoria social, particularmen-te a marxista, é a inserção de classe dos trabalhadores assalariados não-manuais. A diversidade terminológica conferida a este segmento social – classe média, proletários educados, terciários, colarinhos brancos, nova pe-quena burguesia, posições contraditórias de classe, assalariados médios, grupos funcionais – é apenas uma mostra diante da polêmica propriamente dita travada pela bibliografia.O objetivo deste texto é discutir o encaminhamento dado pelo pen-samento marxista à inserção daqueles trabalhadores na estrutura de classes.
The prospects for lasting peace and security in Burundi towards development
Authors: Chigudu Daniel
Published: March 2021

Since independence, Burundi has endured civil war episodes, five successful and two unsuccessful coup d’états. The instability resulted in the collapse of the economy despite the consummation of the Arusha Agreement. This study moves away from the propensity to only view the security challenges as pitting Tutsis and Hutus.  Such an analytical tendency generates distortions. This study was qualitative and employed a systematic review research methodology in identifying relevant texts. Document analysis was then used to interpret meaning from documents giving them voice over the study area. The main findings were hinged on conflict causes, key assumptions, violence and instability in the past, impunity and governance, the approach to political realism, truth and reconciliation constraints. This study concludes that although power-sharing could be a necessary move as a measure of building confidence, sharing power is not an adequate condition for sustainable development and peace.
Working capital management practices and sustainability of Barangay Micro Business Enterprises (BMBEs) in Ilocos Norte, Philippines
Authors: Macatumbas Corpuz Bibeth , Bool Nelson
Published: March 2021

This study examines the relationship between the working capital management practices and sustainability of Barangay Micro Business Enterprises (BMBEs) in Ilocos Norte, Philippines. This study employed a correlational-descriptive research design. Data were gathered using a self-constructed questionnaire, which has been pre-tested to 30 other microenterprises and validated using Cronbach alpha. The participants were the owners of the 301 registered BMBEs in Ilocos Norte. This study was conducted from July to December 2020. The findings demonstrated that most of the BMBEs belong to the wholesale and retail trade sector, are registered as single proprietorships, and have no employees. The results also showed that the BMBEs have low economic, social, and environmental sustainability. Moreover, the study revealed that cash management was significantly related to economic and social sustainability, while accounts receivable and inventory management were significantly related to economic, social, and environmental sustainability.
Exploring the relationship between Job autonomy and employee engagement in turbulent times
Authors: Kidane Abay , Xuefeng Zhao
Published: March 2021

This study aims to develop and test a holistic model that depicts and examines the relationships among job autonomy, its drivers, as well as autonomous motivation and influence employee engagement. This research is among the first works to deal with such a complex framework that considers the interrelationships among numerous constructs and their effects on employee engagement. A questionnaire was designed to measure the influence of Job autonomy and its drivers on employee engagement while taking into consideration the impact of turbulent times and organizational commitment on these relationships. Data collected from a sample of 317 respondents working in Ethiopian commercial banks were used to test the proposed relationships. The relationships were analyzed using partial least squares structural equation modeling (PLS-SEM) using the Smart PLS 3 software and SPSS version 26. PLS is a well-established technique for estimating path coefficients in structural models and has been widely used in a number of research studies.  The proposed model proved to be fit. The findings of this study suggest that creating job autonomy and assuring autonomous motivation, may help companies gain employee engagement and enhance their performance. The adoption and implementation of such activities are driven by method, criteria, and scheduling autonomy. The successful implementation of these practices requires considering the level of turbulent environment and organizational tenure. The hypotheses were supported, and implications were discussed
PENINGKATAN KEMAMPUAN PROMOSI MELALUI PELATIHAN DESAIN PROMOSI BERBASIS TEKNOLOGI QR-CODE
Authors: Muliyati Dewi , Siswoyo S
Published: March 2021

Information and communication technology (ICT) contributes significantly to the optimization of the promotional design. QR-Code is one of the technologies that can improve promotional media to be more informative and interactive, especially visual media. The various information embedded in the QR-Code can provide varied impressions to the user. On many occasions, QR-Code can even direct to transactions. This advantage is packaged in a simple appearance because it is a one-dimensional to two-dimensional development of barcodes. These characteristics make QR-Code as a designing promotional media technology that every business actor must mastering. This paper describes the training conducted to improve promotional design skills that are integrated with QR-Code technology. The training is carried out in collaboration with Rumah Siap Kerja, through the video conference platform. The training results show an increase in knowledge and skills in integrating QR-Code technology into promotional media.

Teknologi informasi dan komunikasi (TIK) berkontribusi besar dalam optimasi desain promosi. QR-Code menjadi salah satu pilihan teknologi yang mampu meningkatkan media promosi menjadi lebih informatif dan interaktif, terutama media promosi jenis visual. Berbagai informasi yang ditanamkan dalam QR-Code dapat memberikan impresi yang bervariatif kepada pengguna. Dalam banyak kesempatan, QR-Code bahkan dapat mengarahkan terjadinya transaksi. Keunggulan ini dikemas dalam tampilan yang sederhana karena pada dasarnya merupakan pengembangan barcode satu dimensi ke dua dimensi. Karakteristik ini menjadikan QR-Code sebagai teknologi yang wajib dikuasai oleh setiap pelaku usaha dalam mendesain media promosi. Makalah ini memaparkan pelatihan yang dilakukan untuk meningkatkan kemampuan desain promosi yang terintegrasi dengan teknologi QR-Code. Pelatihan dilaksanakan atas kerjasama dengan Rumah Siap Kerja secara daring melalui platform video conferences. Hasil pelatihan menunjukkan peningkatan pengetahuan dan keterampilan dalam mengintegrasikan teknologi QR-Code ke dalam media promosi.
Effect of Postoperative Analgesic Exposure to the Cannabinoid Receptor Agonist WIN55 on Osteogenic Differentiation and Spinal Fusion in Rats
Authors: Yun Chawon , Haleem Meraaj S. , Jeong Soyeon , Oyer Mark A. , Driscoll Adam J. , Chang Kevin Y. , Yun Jonghwa , Paul Jonathan , Lubbe Ryan J. , Stock Stuart R. , Hsu Wellington K. , Hsu Erin L.
Published: March 2021

Background:

After spinal surgery and other orthopaedic procedures, most patients receive opioids for pain, leading to potential complications such as pseudarthrosis and opioid abuse associated with long-term use. As an alternative, the endocannabinoid system has been shown to have antinociceptive activity, while contributing to bone homeostasis via the CB1 and CB2 cannabinoid receptors. This study evaluates the impact of the cannabinoid receptor agonist WIN55,212-2 (WIN55) on osteogenic differentiation in vitro as well as bone regeneration and spinal fusion in a preclinical rat model.

Methods:

Primary rat bone marrow stromal cells were cultured in standard or osteogenic media and exposed to vehicle alone or WIN55. Runx2 and Alkaline phosphatase (Alpl) were quantified via qPCR (quantitative real-time polymerase chain reaction), followed by assessment of ALP activity and matrix mineralization. For in vivo evaluation, 45 female Sprague Dawley rats (n = 15 per group) underwent L4-L5 posterolateral spinal fusion with bilateral placement of collagen scaffolds preloaded with low-dose rhBMP-2 (recombinant human bone morphogenetic protein-2; 0.5 μg/implant). Postoperatively, rats received the vehicle alone or 0.5 or 2.5 mg/kg WIN55 via daily intraperitoneal injections for 5 days. Bone regeneration and spinal fusion were assessed using radiography, manual palpation-based fusion scoring, microcomputed tomography imaging, and histology.

Results:

mRNA expression levels of Runx2 and Alp were similar among cells treated with vehicle alone and WIN55. Likewise, exposure to WIN55 did not inhibit ALP activity or bone matrix mineralization. In this animal model, no significant differences were found among groups with regard to mean fusion score, fusion rate, or new bone volume.

Conclusions:

WIN55 showed no adverse impact on osteogenic differentiation, bone regeneration, and spinal fusion. This supports that cannabinoid receptor agonists should be further investigated as a potential alternative approach for postoperative analgesia following spinal fusion and other orthopaedic procedures requiring bone-healing.

Clinical Relevance:

The identification of alternative treatments for postoperative pain following orthopaedic surgical procedures is crucial in combating the ongoing opioid abuse crisis. The endocannabinoid system may represent a viable alternative target for addressing orthopaedic postoperative pain.
Hydromechanical-Coupled Cohesive Interface Simulation of Complex Fracture Network Induced by Hydrofracturing with Low-Viscosity Supercritical CO2
Authors: Cai Xin , Liu Wei
Published: March 2021

Hydraulic fracturing experiments with low-viscosity fluids, such as supercritical CO2, demonstrate the formation of complex fracture networks spread throughout the rocks. To study the influence of viscosity of the fracturing fluids on hydraulic fracture propagation, a hydromechanical-coupled cohesive zone model is proposed for the simulation of mechanical response of rock grains boundary separation. This simulation methodology considers the synergistic effects of unsteady flow in fracture and rock grain deformation induced by hydraulic pressure. The simulation results indicate a tendency of complex fracture propagation with more branches as the viscosity of fracturing fluids decrease, which is in accord with experimental results. The low-viscosity fluid can flow into the microfractures with extremely small aperture and create more shear failed fracture. This study confirms the possibility of effective well stimulations by hydraulic fracturing with low-viscosity fluids.
An Accurate, Robust and Low Dimensionality Deep Learning Localization Approach in DM-MIMO Systems Based on RSS
Authors: Moosavi Seyedeh Samira , Fortier Paul
Published: March 2021

Currently, localization in distributed massive MIMO (DM-MIMO) systems based on the fingerprinting (FP) approach has attracted great interest. However, this method suffers from severe multipath and signal degradation such that its accuracy is deteriorated in complex propagation environments, which results in variable
received signal strength (RSS).
Therefore, providing robust and accurate localization is the goal of this work. In this paper, we propose an FP-based approach to improve the accuracy of localization by reducing the noise and the dimensions of the RSS data. In the proposed approach, the fingerprints rely solely on the RSS from the single-antenna MT collected at each of the receive antenna elements of the massive MIMO base station. After creating a radio map, principal component analysis (PCA) is performed to reduce the noise and redundancy. PCA reduces the data dimension which leads to the selection of the appropriate antennas and reduces complexity. A clustering algorithm based on K-means and affinity propagation clustering (APC) is employed to divide the whole area into several regions which improves positioning precision and reduces complexity and latency. Finally, in order to have high precise localization estimation, all similar data in each cluster are modeled using a well-designed deep neural network (DNN) regression.
Simulation results show that the proposed scheme improves positioning accuracy significantly. This approach has high coverage and improves average root-mean-squared error (RMSE) performance to a few meters, which is expected in 5G and beyond networks. Consequently, it also proves the superiority of the proposed method over the previous location estimation schemes.
Mitigating the effect of COVID lockdown period on Channel and Bandwidth Utilization in Mobile Communication Network in North Western Rajasthan (India)
Authors: PUROHIT HEMANT , Kaur Parneet , Choudhary Shilpa
Published: March 2021

The COVID – 19 lockdown has led all the citizens (mobile subscribers) of India to stay at home and rather work from home. The people have started consuming more channel utilization (in mobile communication) through a continuous long duration conversations and more internet data through more streaming content as well as logging on to work from home. It was also reflected in how data demand from residential areas rose as compared to commercial areas. Consequently the bandwidth and channel saturation has evolved out to be a severe problem thereby affecting the work performance of all online offices and multi-national companies. This research paper proposes the simulation based experimental study of DITMC technique for mitigating this effect with a special concern in North Western Rajasthan part of India. The simulation results show that significant enhancement of 60.52% in channel utilization and bandwidth optimization is possible with negligible overhead of 0.23%. This technique also enables the telecom operators to ponder research in this field that will promisingly lead to manage augmented number of mobile subscribers (independent of any lockdown period) in limited bandwidth thereby using the spectrum efficiently.
A Fresh Design of Power Effective Adapted Vedic Multiplier for Modern Digital Signal Processors
Authors: Gavaskar K , Malathi D , Ravivarma G , Devi V Krithika , Megala M , Begam S Megaraj
Published: March 2021

The Multiply Accumulate (MAC) unit constructed using antiquated Vedic mathematical practice and the efficiency of the vertical and transversely of Vedic approach for multiplication, which gives a distinction in genuine cycle of Multiplier itself. Vedic-Mathematics is depend on 16-Sutras, in that Urdhva-Triyakbhyam (UT) more productive one. It literally means vertical and cross wise operations. It eliminates unwanted multiplication and allows the parallel creation of partial products and addition steps. The adders are utilized to append the partial-product generated in the Vedic mathematics methodology to drops the combinational lag. MAC is an essential unit in the digital signal processors, to show the characters like speed, power as well as area. Hence, finer multiplier plans are to increase the order of the system. The Modified sum product algorithm based Vedic multiplier is one such promising solution. It has a rapid multiplication process and reaches a less calculation complexity above its traditional multiplier. Array multiplier, Baugh-Wooley multiplier, Wallace-tree multiplier and Vedic multiplier were created in the existing work. In proposed work Vedic multiplier, using modified sum product algorithm was designed. The structure design coded in verilog and parameter analysis was done in Xilinx. The parameters like delay as well as power were compare between existing and proposed. When comparing with different multiplier with our proposed work delay get reduced. Comparing with existing multiplier the proposed 4x4 Vedic multiplier have 49.12% reduction in delay. Comparing with existing multiplier the proposed Vedic 4x4 multiplier have 42.51% reduction in power.
A Facile and Versatile Approach for the Synthesis of Degradable Polymers via Controlled Ring-Opening Metathesis Copolymerization
Authors: Feist John , Lee Daniel , Xia Yan
Published: March 2021

The authors have requested that this preprint be removed from Research Square.
Reflective and Transparent Cellulose-Based Passive Radiative Coolers
Authors: Gamage Sampath , Alam Md. Mehebub , Hallberg Tomas , Akerlind Chriatina , Sultana Ayesha , Berggren Magnus , Crispin Xavier , Kariis Hans , Zhao Dan , Jonsson Magnus
Published: March 2021

Radiative cooling passively removes heat from objects via emission of thermal radiation to cold space. Suitable radiative cooling materials absorb infrared light while they avoid solar heating by either reflecting or transmitting solar radiation, depending on the application. Here, we demonstrate a reflective radiative cooler and a transparent radiative cooler solely based on cellulose derivatives manufactured via electrospinning and casting, respectively. By modifying the microstructure of cellulose materials, we can control the solar light interaction from highly reflective (>90%, porous structure) to highly transparent (≈90%, homogenous structure). Both cellulose materials show strong thermal emissivity and minimal solar absorption, making them suitable for daytime radiative cooling. Used as coatings on silicon samples exposed to sun light at daytime, the reflective and transparent cellulose coolers could passively reduce sample temperatures by up to 32 °C and 15 °C, respectively.
Preparation of Cerium Oxide-MWCNTs Nanocomposite Bulk Modified Carbon Ceramic Electrode: A Sensitive Sensor for Tamoxifen Determination in Human Serum Samples
Authors: Shafaei Sepideh , Hosseinzadeh Elyas , Kanberoglu Gulsah Saydan , Khalilzadeh Balal , Mohammad-Rezaei Rahim
Published: March 2021

In this study, cerium oxide and multi-walled carbon nanotubes nanocomposite was incorporated into the carbon ceramic electrode (CeO2-MWCNTs/CCE) as a renewable electrode for the electrocatalytic purposes. To demonstrate capability of the fabricated electrode, determination of Tamoxifen as an important anticancer drug with differential pulse voltammetry technique was evaluated. Linear range, limit of detection and sensitivity of the developed sensor were found to be 0.2-40 nM, 0.132 nM and 1.478 µA nM-1 cm-2, respectively. Ease of production, low cost and high electron transfer rate of CeO2-MWCNTs/CCE promise it as a novel electro-analytical tool for determination of important species in real samples.
Fast Cluster-based Computation of Exact Betweenness Centrality in Large Graphs
Authors: Daniel Cecile , Furno Angelo , Goglia Lorenzo , Zimeo Eugenio
Published: March 2021

Nowadays a large amount of data is originated by complex systems, such as social networks, transportation systems, computer and service networks. These systems can be modeled by using graphs and studied by exploiting graph metrics, such as Betweenness Centrality (BC), a popular metric to analyze node centrality of graphs. In spite of its great potential, this metric requires long computation time, especially for large graphs.

In this paper, we present a very fast algorithm to compute BC of undirected graphs by exploiting clustering. The algorithm leverages structural properties of graphs to find classes of equivalent nodes: by selecting one representative node for each class, we are able to compute BC by significantly reducing the number of single-source shortest path explorations adopted by Brandes' algorithm. We formally prove the graph properties that we exploit to define the algorithm and present an implementation based on Scala for both sequential and parallel map-reduce executions.

The experimental evaluation of both versions, conducted with synthetic and real graphs, reveals that our solution largely outperforms Brandes' algorithm and significantly improves known heuristics.
A Comparative Analysis of Clinical Characteristics and Laboratory Findings of COVID-19 between Intensive Care Unit and Non-Intensive Care Unit Pediatric Patients: A Multicenter, Retrospective, Observational Study from Iranian Network for Research in Viral Diseases (INRVD)
Authors: Fahimzad Alireza , Sedighi Iraj , Pak Neda , Khalili Mitra , Farahmand Mohammad , Shokrollahi Mohammad Reza , Heydari Hosein , Movahedi Zahra , Dashti Anahita Sanaei , Cheraghali Fatemeh , Shamsizadeh Ahmad , Mirkarimi Mohammadreza , Alisamir Mohsen , Hashemian Houman , Soltani Jafar , Hosseininasab Ali , Hamedi Abdolkarim , Rezai Mohammad Sadegh , Sayyahfar Shirin , Kahbazi Manijeh , Abedini Aliakbar , Akhondzadeh Afsaneh , Sherkatolabbasieh Hamid Reza , Razlansari Ali Akbar , Alibeik Mina , Malayeri Soheil Omid , Shalchi Zohreh , Shahabinezhad Ali , Asl Parinaz Khalkhali , Monfared Fatemeh Nafe , Maleki Shiva , Kakavand Rezvan , Shahbaz Babak , Poortahmasebi Vahdat , Rezayat Sara Akhavan , Karimi Mohammad Reza , Jafarpour Ali , Soltani Saber , Ghaziasadi Azam , Dowran Razieh , Azimi Shohreh , Marvi Shima Sadeghipour , Abazari Foad , Zandi Milad , Yaghoobzadeh Delaram , Jazayeri Seyed Mohammad , Tavakoli Ahmad
Published: March 2021

Background: To date, less is known about the clinical features of COVID-19 pediatric patients admitting to ICUs. Herein, we aimed to describe the differences in demographic characteristics, laboratory findings, clinical presentations, and outcomes between COVID-19 pediatric patients admitting to ICU and non-ICU settings.Methods: This multicenter study involved 15 general and pediatrics hospitals on confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection by positive real-time reverse transcription polymerase chain reaction (RT-PCR) between March 19 and May 31, 2020, during the initial peak of the COVID-19 pandemic in Iran.Results: Overall, 166 patients were included, of which 61 (36.7%) required ICU admission, especially in <5 years old age group. Malignancy and heart diseases were the most frequent underlying condition. There was significant decrease in platelet counts, PH, HCO3 and base excess as well as increases in creatinine, creatine phosphokinase and potassium levels between ICU-admitted and non-ICU patients. Dyspnea was the major symptom for ICU group patients. Acute respiratory distress syndrome (ARDS), shock and acute cardiac injury were the most common features among ICU-admitted patients. The mortality rate was substantially higher in the ICU than in non-ICU patients (45.9% vs. 1.9%, respectively; P<0.001).Conclusions: Underlying diseases were the major contributing factors in COVID-19 pediatric patients for the increased ICU admissions and mortality rates. There are few paraclinical parameters for differentiating pediatrics in terms of prognosis and serious outcomes of COVID-19. Healthcare providers should consider children as a high-risk group, especially those with younger age and underlying medical conditions and define strategies to control and prevent COVID-19 transmission in this population.
Yak Dung Seed Bank on the Qinghai-Tibetan Plateau: Effects of Grazing Season, Seed Characteristics and Forage Preferences
Authors: Wang Shulin , Hou Fu-Jiang
Published: March 2021

AimsViable seeds in herbivore dung constitute the dung seed bank, and the contribution of livestock dung to this seed bank in grazing pastures is often overlooked. Grazing season (warm and cold), seed characteristics (mass and shape), and forage preference are the main factors that affect the size and composition of the dung seed bank and ultimately affect grassland ecology. However, how these three factors interact is unclear. Methodswe collected yak dung as well as seeds of the common plant species from warm- and cold-season alpine meadows in northeastern Qinghai-Tibetan Plateau, and explored how grazing season (warm and cold), seed characteristics (size and shape) and foraging preferences (temporary cages method) affects yak dung seedling density, richness and diversity in an alpine pasture on the northeastern Qinghai-Tibetan Plateau. ResultsForty-three plant species (mainly perennials) could germinate from yak dung. Dung seedling density, richness, and diversity did not differ significantly between the two grazing seasons. Small-to-medium-sized spherical seeds (seed mass < 10 mg, shape index < 0.5) had the greatest germination potential. ConclusionsYaks vary their forage preference depending on the season (phenological period), and endozoochory occurs throughout both grazing seasons. Seed shape and mass directly regulate the dung seedling density, richness, and diversity. Dung seedlings increase the heterogeneity of the aboveground vegetation near the microsites of the dung pieces and therefore promote grassland patching. Our study demonstrates that grazing season, seed characteristics, and yak forage preferences affect the dung seed bank in grazing ecosystems.
An Eye Tracking Based Virtual Reality System for Use Inside Magnetic Resonance Imaging Systems
Authors: Qian Kun , Arichi Tomoki , Price Anthony , Dall’Orso Sofia , Eden Jonathan , Noh Yohan , Rhode Kawal , Burdet Etienne , Neil Mark , Edwards A David , Hajnal Joseph V
Published: March 2021

Patients undergoing Magnetic Resonance Imaging (MRI) often experience anxiety and sometimes distress prior to and during scanning. Here a full MRI compatible virtual reality (VR) system is described and tested with the aim of creating a radically different experience. Potential benefits could accrue from the strong sense of immersion that can be created with VR, which could create sense experiences designed to avoid the perception of being enclosed and could also provide new modes of diversion and interaction that could make even lengthy MRI examinations much less challenging. Most current VR systems rely on head mounted displays combined with head motion tracking to achieve and maintain a visceral sense of a tangible virtual world, but this technology and approach encourages physical motion, which would be unacceptable and could be physically incompatible for MRI. The proposed VR system uses gaze tracking to control and interact with a virtual world. MRI compatible cameras are used to allow real time eye tracking and robust gaze tracking is achieved through an adaptive calibration strategy in which each successive VR interaction initiated by the subject updates the gaze estimation model. A dedicated VR framework has been developed including a rich virtual world and gaze-controlled game content. To aid in achieving immersive experiences physical sensations, including noise, vibration and proprioception associated with patient table movements, have been made congruent with the presented virtual scene. A live video link allows subject-carer interaction, projecting a supportive presence into the virtual world.
Willingness to use HIV pre-exposure prophylaxis and associated factors among men who have sex with men in Liuzhou, China
Authors: Fu Yuansheng , Ashuro Akililu Alemu , Feng Xianxiang , Wang Ting , Zhang Sichen , Ye Dongqing , Fan Yin Guang
Published: March 2021

Background: HIV pre-exposure prophylaxis (PrEP) is a key component of HIV combination prevention strategies, which has the potential to decrease the incidence of HIV in men who have sex with men (MSM). This study aimed to evaluate the levels of PrEP acceptability and explore the factors associated with willingness to use PrEP among MSM in Liuzhou, China.Methods: Between November 2017 and May 2019, a cross-sectional survey was conducted among 829 MSM. The study participant were recruited through nonprobability sampling method. Participants’ demographics, HIV/AIDS knowledge, sexual behaviors, drug use and HIV test history were collected. Multivariate logistic regression was performed to identify factors associated with willingness to use PrEP.Results: A total of 829 MSM completed the survey, and 30.28%(95%CI: 27.3-33.4) were willing to use PrEP. In multivariate logistic regression, factors associated with a higher willingness to use PrEP include, being Zhuang or Han ethnic origin, recruited through peer introduction or gay venues, pursing higher education level, previous HIV testing and having oral sex with a man. However, had a casual sex in the past six months were associated with lower willingness to use PrEP.Conclusions: MSM in Liuzhou reported a relatively low level of willingness to use PrEP. The results indicate the need for effective education, targeted intervention, and define implementation strategies to promote PrEP acceptance among MSM.
Hanging glacier avalanche (Raunthigad - Rishiganga) and Debris flow disaster of 7th February 2021, Uttarakhand, India, A Preliminary assessment
Authors: Thayyen Renoj J , Mishra P.K , Jain Sanjay K. , Wani John Mohd , Singh Hemant , Singh Mritunjay K. , Yadav Bankim
Published: March 2021

A catastrophic debris flow in the Rishiganga and Dhauli ganga river in Uttarakhand, India on 7th February 2021 left a trail of disaster. Around 200 people lost their lives, two hydro-power project were badly damaged and a bridge across the Rishiganga River was washed off in the event. Study shows that the debris flow is caused due detachment of 0.59 km2 right lobe of a hanging glacier and resultant ice-rock avalanche. This right lobe of the glacier was located over a mountain slope having an average slope of 35o at 4700–5555 m a.s.l. and travelled 12.4 km before hitting the infrastructure projects. Role of precipitation, snow cover, land surface temperature and permafrost processes were investigated for identifying causes of the event. Since 2012, monsoon precipitation and mean annual land surface temperature (LST) showed significant increasing trend. Snow cover during monsoon months showed increasing trend and September, October and November experienced decreasing trend at glacier elevations. Mean annual LST increased from − 0.3 oC in 2012 to a peak of 0.4 oC in 2016. Central lobe of the glacier advanced during this period and eventually fell off in 2016 suggesting that the LST warming forced reduction of frictional drag at the interface facilitating it advancement and eventual dislodgement. Permafrost modelling suggest warm permafrost below 50 m and conditions favorable for intense frost cracking at to 10–15 m. At ~ 40 m depth, the delayed response of 2012–2016 warming produced peak positive temperature conditions by December and probably facilitated the formation of thin film of water at the deeper layers acting as a lubricant for glacier sliding. It is also suggested that the increase in summer precipitation might have forced thickening of the accumulation area and thereby increasing the shear stress for sliding of the glacier. It is proposed that the recent change in the weather conditions in the region is primarily responsible for this event through geological, glaciological and permafrost processes. Flood modeling study suggest a flood volume of ~ 10 MCM generating 24.5 m flow depth at the bridge site with 12.7 m/s flow velocity. The event highlighted the need for improved monitoring of the cryospheric areas of the Himalaya to capture the early warning signs for better preparedness.
Model Order Reduction based on Direct Normal Form: Application to Large Finite Element MEMS Structures Featuring Internal Resonance
Authors: Opreni Andrea , Vizzaccaro Alessandra , Frangi Attilio , Touzé Cyril
Published: March 2021

Dimensionality reduction in mechanical vibratory systems poses challenges for distributed structures including geometric nonlinearities, mainly because of the lack of invariance of the linear subspaces. A reduction method based on direct normal form computation for large finite element (FE) models is here detailed. The main advantage resides in operating directly from the physical space, hence avoiding the computation of the complete eigenfunctions spectrum. Explicit solutions are given, thus enabling a fully non-intrusive version of the reduction method. The reduced dynamics is obtained from the normal form of the geometrically nonlinear mechanical problem, free of non-resonant monomials, and truncated to the selected master coordinates, thus making a direct link with the parametrisation of invariant manifolds. The method is fully expressed with a complex-valued formalism by detailing the homological equations in a systematic manner, and the link with real-valued expressions is established. A special emphasis is put on the treatment of second-order internal resonances and the specific case of a 1:2 resonance is made explicit. Finally, applications to large-scale models of Micro-Electro-Mechanical structures featuring 1:2 and 1:3 resonances are reported, along with considerations on computational efficiency.
Achieving Macroscale Liquid Superlubricity Using Lubricant Mixtures of Glycerol and Diols
Authors: Ma Qiang , Wang Wei , Dong Guangneng
Published: March 2021

Friction and wear are ubiquitous in moving mechanical systems, and achieving vanishing friction and wear could significantly improve energy efficiency and extend the service life of mechanical components. In this paper, various diols, viz. ethylene glycol (EG), 1,3-propanediol (13-PD), and 1,2-propdiol (12-PD), have been selected to be mixed with glycerol for superlubricity performance. The results show that the lubricant mixture of EG and glycerol (EG/glycerol) and the mixture of 13-PD and glycerol (13-PD/glycerol) are effective in providing superlow friction (COF < 0.01) for steel tribopairs under ambient atmosphere environment with little surface damage caused. However, 12-PD, which exhibits the same chemical formula as 13-PD except for the configuration of hydroxyl groups, is ineffective for superlubrication. Furthermore, compared with 13-PD, EG is more efficient in preparing superlubric lubricants. Experimental and molecular dynamics simulation results show that the superlow friction realized by the lubricant mixtures of glycerol and diols is related to their intermolecular hydrogen-bonding interaction and the adsorbed formation of adsorbed molecular layers. The intermolecular interaction could affect the rheological property of lubricant mixtures and the hydrodynamic lubricant film-forming capability at the interface, while the quality of the adsorbed molecular layers determines the passivating efficiency for asperity interactions between opposite surfaces. Due to the atomic structure difference, EG is the most desirable diol for this objective, followed by 13-PD, while 12-PD is ineffective. These findings could help enable the rational design of novel lubricants for superlubricating performance and push the development of liquid superlubricity for future engineering applications.
Characterization of Three GADs from Bacillus spp. for Efficient γ-Aminobutyric Acid Production
Authors: Sun Lei , Bai Yingguo , Zhang Xiu , Zhou Cheng , Zhang Jie , Su Xiaoyun , Luo Huiying , Yao Bin , Wang Yuan , Tu Tao
Published: March 2021

BackgroundGamma-aminobutyric acid (GABA) is an important bio-product used in pharmaceuticals and functional foods and as a precursor of the biodegradable plastic polyamide 4. Glutamate decarboxylase (GAD) converts l-glutamate (l-Glu) into GABA via decarboxylation. Compared with other methods, develop a bioconversion platform to produce GABA is of considerable interest for industrial use.ResultsThree GAD genes were identified from three Bacillus strains and heterologously expressed in Escherichia coli BL21 (DE3). The optimal reaction temperature and pH values for three enzymes were 40 °C and 5.0, respectively. Of the GADs, GADZ11 had the highest catalytic efficiency towards l-Glu (2.19 mM− 1·s− 1). The engineered E. coli strain that expressed GADZ11 was used as a whole-cell biocatalyst for the production of GABA. After repeated use 8 times, the cells produced GABA with an average molar conversion rate of 97% within 8 h.ConclusionsThree recombinant GADs from Bacillus strains have been conducted functional identification. And engineered E. coli strain heterologous expressing GADZ1, GADZ11, and GADZ20 could accomplish the biosynthesis of l-Glu to GABA in a buffer-free reaction at a high l-Glu concentration. The novel engineered E. coli strain has the potential to be a cost-effective biotransformation platform for the industrial production of GABA.
Analysis the characteristic of energy and damage of coal-rock composite structure under cycle loading
Authors: Li Tan , Chen Guangbo , Qin Zhongcheng , Li Qinghai
Published: March 2021

The stability of coal-rock composite structures is of great significance to coal mine safety production. To study the stability and deformation failure characteristics of the coal-rock composite structure, the uniaxial cyclic loading tests of the coal-rock composite structures with different coal-rock height ratios were carried out. Lithology and coal-rock height ratio play an important role in the energy dissipation of coal-rock composite structures. The higher the coal-rock height ratio, the greater the average elastic energy and dissipated energy produced per cycle of coal-rock composite structures, the smaller the total elastic energy and dissipated energy produced in the process of cyclic loading. Based on the difference of damage variables calculated by dissipative energy method and acoustic emission method, a more sensitive joint calculation method for calculating damage variable was proposed. The joint damage variable calculation method can more accurately and sensitively reflect the damage of coal-rock composite structure under cyclic loading. The macroscopic crack first appears in the coal specimen in the coal-rock composite structure, the degree of broken coal specimens in the composite structure is inversely proportional to the coal-rock height ratio. The strength and deformation characteristics of the coal-rock composite structure are mainly affected by coal sample in the composite structure.