bluuebunny/crossref_metadata_2025 huggingface dataset:
Sedimentation rate and organic matter dynamics shape microbiomes across a continental margin
Authors: Bhattacharya Sabyasachi , Mapder Tarunendu , Fernandes Svetlana , Roy Chayan , Sarkar Jagannath , Rameez Moidu Jameela , Mandal Subhrangshu , Sar Abhijit , Chakraborty Amit Kumar , Mondal Nibendu , Chatterjee Sumit , Dam Bomba , Peketi Aditya , Chakraborty Ranadhir , Mazumdar Aninda , Ghosh Wriddhiman
Published: February 2021

Abstract. Marine sedimentation rate and bottom-water O2 concentration control the remineralization/sequestration of organic carbon across continental margins; but whether/how they shape microbiome architecture (the ultimate effector of all biogeochemical phenomena), across shelf/slope sediments, is unknown. Here we reveal distinct microbiome structures and functions, amidst comparable pore fluid chemistries, along 300 cm sediment horizons underlying the seasonal (shallow coastal) and perennial (deep sea) oxygen minimum zones (OMZs) of the Arabian Sea, situated across the western-Indian margin (water-depths: 31 m and, 530 and 580 m, respectively). The sedimentary geomicrobiology was elucidated by analyzing metagenomes, metatranscriptomes, and enrichment cultures, and also sedimentation rates measured by radiocarbon and lead excess (210Pbxs); the findings were then evaluated in the light of the other geochemical data available for the cores investigated. Along the perennial- and seasonal-OMZ sediment cores, microbial communities were dominated by Gammaproteobacteria and Alphaproteobacteria, and Euryarchaeota and Firmicutes, respectively. As a perennial-OMZ signature, a cryptic methane production-consumption cycle was found to operate near the sediment-surface (within the sulfate reduction zone); overall diversity, as well as the relative abundances of simple-fatty-acids-requiring anaerobes (methanogens, anaerobic methane-oxidizers, sulfate-reducers and acetogens), peaked in the topmost sediment-layer and then declined via synchronized fluctuations until the sulfate-methane transition zone was reached. The entire microbiome profile was reverse in the seasonal-OMZ sediment horizon. In the perennial-OMZ sediments organic carbon deposited was higher in concentration and marine components-rich, so it potentially degraded readily to simple fatty acids; lower sedimentation rate afforded higher O2 exposure time for organic matter degradation despite perennial hypoxia in the bottom-water; thus, the resultant abundance of reduced carbon substrates sustained multiple inter-competing microbial processes in the upper sediment-layers. Remarkably, the whole geomicrobial scenario was opposite in the sediments of the seasonal/shallow-water OMZ. Our findings create a microbiological baseline for understanding carbon-sulfur cycling across distinct marine depositional settings and water-column oxygenation regimes.
Evaluation of changes in some physico-chemical properties of bottled water exposed to sunlight in Bauchi State, Nigeria
Authors: Daffi Rose E. , Wamyil Fwangmun B.
Published: February 2021

Abstract. It is common for bottled water and other assorted drinks to be seen displayed outside stores and in the sun in most parts of Nigeria. The country is mostly hot year-round, and over the course of the year, temperatures can rise to as high as 40 ∘C around March–April in the study area. The leaching effect of chemicals from polyethylene terephthalate (PET) bottled water was investigated for five commercially available bottled water brands. Temperature, pH, antimony, bisphenol A (BPA), and nitrate levels were measured on days 0, 14, and 28 for control samples and samples exposed to direct sunlight, using destructive sampling technique. Antimony was not detected in brands A, B, and E in the baseline measurement at day 0, while brands C and D had low values; after 28 d all the control
samples still had antimony levels within the United States Environmental
Protection Agency (US EPA) standard. Meanwhile, all the samples exposed to
sunlight exceeded US EPA standard levels at 14 and 28 d, except brand A
which was within limit at 14 d with value of 4.59 µg L−1. All control
and exposed samples were below the European Union Drinking Water Directive
(EU DWD) total daily intake (TDI) of BPA (0.05 mg per kilogram of body
weight)−1 d−1. Values obtained for nitrate showed that all control samples did not exceed the US EPA guideline level for nitrates in drinking water for days 0, 14, and 28, while three of the samples, i.e. brands C, D, and E, exceeded the guideline level at day 28. Exposure of bottled water to sunlight was seen to impair the quality of the water for consumption.
Database of global glendonite and ikaite records throughout the Phanerozoic
Authors: Rogov Mikhail , Ershova Victoria , Vereshchagin Oleg , Vasileva Kseniia , Mikhailova Kseniia , Krylov Aleksei
Published: February 2021

Abstract. This database of Phanerozoic occurrences and isotopic
characteristics of metastable cold-water calcium carbonate hexahydrate
(ikaite; CaCO3⚫6H2O) and their associated carbonate
pseudomorphs (glendonites) has been compiled from academic publications,
explanatory notes, and reports. Our database including more than 700
occurrences reveals that glendonites characterize cold-water environments,
although their distribution is highly irregular in space and time. A
significant body of evidence suggests that glendonite occurrences are
restricted mainly to cold-water settings; however they do not occur during
every glaciation or cooling event of the Phanerozoic. While Quaternary
glendonites and ikaites have been described from all major ocean basins,
older occurrences have a patchy distribution, which may suggest poor
preservation potential of both carbonate concretions and older sediments. The data file described in this paper is available on Zenodo at
https://doi.org/10.5281/zenodo.4386335 (Rogov et al., 2020).
A zero-dimensional view of atmospheric degradation of levoglucosan (LEVCHEM_v1) using numerical chamber simulations
Authors: Suciu Loredana G. , Griffin Robert J. , Masiello Caroline A.
Published: February 2021

Abstract. Here, we developed a zero-dimensional (0-D) modeling framework (LEVCHEM_v1) to provide insights into the atmospheric degradation of a key tracer emitted during biomass burning – levoglucosan (LEV), while additionally exploring its effects on the dynamics of secondary organic aerosols (SOA) and other gases. For this, we updated existing chemical mechanisms (homogeneous gas-phase chemistry and heterogeneous chemistry) in the BOXMOXv1.7 model to include the chemical degradation of LEV and its intermediary degradation products in both phases (gas and aerosol). In addition, we added a gas-particle partitioning mechanism to the model to account for the effect of evaporation and condensation on the phase-specific concentrations of LEV and its degradation products. Comparison of simulation results with measurements from various chamber experiments (spanning summer and winter conditions) show that the degradation timescale of LEV varied by phase, with gas-phase degradation occurring over ∼1.5–5 d and aerosol-phase degradation occurring over ∼8–36 h. These relatively short timescales suggest that most of the initial LEV concentration can be lost chemically or deposited locally before being transported regionally. We varied the heterogeneous reaction rate constant in a sensitivity analysis (for summer
conditions only) and found that longer degradation timescales of LEV are
possible, particularly in the aerosol phase (7 d), implying that some LEV may be transported regionally. The multiphase chemical degradation of LEV has effects on SOA and other
gases. Several first- or second-generation products resulted from its
degradation; most of the products include one or two carbonyl groups, one
product contains a nitrate group, and a few products show the cleavage of C−C
bonds. The relative importance of the products varies depending on the phase
and the timing of the maximum concentration achieved during the
simulation. Our estimated secondary organic aerosol SOA yields
(4 %–32 %) reveal that conversion of LEV to secondary products is
significant and occurs rapidly in the studied scenarios. LEV degradation
affected other gases by increasing the concentrations of radicals and
decreasing those of reactive nitrogen species. Decreases of the mixing ratios
of nitrogen oxides appear to drive a more rapid increase in ozone compared with
changes in volatile organic compounds levels. An important next step to confirm longer degradation timescales will be to
extend the evaluation of the modeled LEV degradation beyond 3–6 h by
using more extensive data from chambers and, possibly, from fire plumes. The
mechanism developed here can be used in chemical transport models applied to
fire plumes to trace LEV and its degradation products from source to
deposition, to assess their atmospheric implications and to answer questions
relevant to fire tracing, carbon and nitrogen cycling, and climate.
Investigating the impact of exit effects on solute transport in macroporous media
Authors: Raimbault Jérôme , Peyneau Pierre-Emmanuel , Courtier-Murias Denis , Bigot Thomas , Gil Roca Jaime , Béchet Béatrice , Lassabatère Laurent
Published: February 2021

Abstract. The effect of macropore flow on solute transport has spurred much research over the last forty years. In this study, non-reactive solute transport in water-saturated columns filled with porous media crossed by a macropore was experimentally and numerically investigated. The emphasis was put on the study of exit effects, whose very existence is inherent to the finite size of any experimental column. We specifically investigated the impact of a filter at the column outlet on water flow and solute transport in macroporous systems. Experiments involving breakthrough measurements and magnetic resonance imaging (MRI) showed that solute transport displayed some significant non-unidirectional features, with a strong mass exchange at the interface between the macropore and the matrix. Fluid dynamics and transport simulations indicated that this was due to the non-unidirectional nature of the flow field close to the outlet filter. The flow near the exit of the column was shown to be strongly impacted by the presence of the outlet filter, which acts as a barrier and redistributes water from the macropore to the matrix. This impact was apparent on the breakthrough curves and the MRI images. It was also confirmed by computer simulations and could, if not properly taken into account, impede the accurate inference of the transport properties of macroporous media from breakthrough experiments.
Formation mechanism analysis and experimental investigation of single-step printing customized circuits by liquid-metal direct writing
Authors: Chao Yan Pu , Yi Hao , Cen Hui , Li Yao Hui
Published: February 2021

Abstract. Liquid-metal direct writing is a cost-effective and green
technology, which is very promising for the customized fabrication of
flexible circuits and functional devices. However, owing to the high surface
tension of metal ink, the printed circuits are prone to intermittent
outflow, large forming size error, and unstable forming. The smooth flowing
and conveying of liquid-metal ink are still huge challenges that need
significant attention. Herein, the force mechanism of liquid-metal ink
transported by ball rotation and translation of the printing head was analysed,
and the wetting characteristics of liquid metal on the surface of different
substrates and its influence on forming morphology were investigated. The
stable output printing of gallium indium alloy (GaIn24.5) liquid metal was
realized. The changing characteristics of the shape and size of the liquid-metal circuits formed under different printing speeds and writing pressures were
experimentally studied. The effective process window for obtaining the best
circuit quality was established. Based on this, a flexible printed circuit
board and functional electronic pattern were successfully printed under the
writing pressure W=1 N and printing speed F800 mm min−1. The printed
lines of GaIn24.5 exhibited a smooth surface, uniform width, small size error,
and ability to connect electronic components and conduct electricity. This
research proposes a new technical approach for customized printing of
personalized electronic circuits and has important application prospects in
the future.
Recent acceleration of Denman Glacier (1972–2017), East Antarctica, driven by grounding line retreat and changes in ice tongue configuration
Authors: Miles Bertie W. J. , Jordan Jim R. , Stokes Chris R. , Jamieson Stewart S. R. , Gudmundsson G. Hilmar , Jenkins Adrian
Published: February 2021

Abstract. After Totten, Denman Glacier is the largest contributor to sea
level rise in East Antarctica. Denman's catchment contains an ice volume
equivalent to 1.5 m of global sea level and sits in the Aurora Subglacial
Basin (ASB). Geological evidence of this basin's sensitivity to past warm
periods, combined with recent observations showing that Denman's ice speed
is accelerating and its grounding line is retreating along a retrograde
slope, has raised the prospect that its contributions to sea level rise
could accelerate. In this study, we produce the first long-term
(∼50 years) record of past glacier behaviour (ice flow speed,
ice tongue structure and calving) and combine these observations with
numerical modelling to explore the likely drivers of its recent change. We
find a spatially widespread acceleration of the Denman system since the
1970s across both its grounded (17±4 % acceleration; 1972–2017)
and floating portions (36±5 % acceleration; 1972–2017). Our
numerical modelling experiments show that a combination of grounding line
retreat, ice tongue thinning and the unpinning of Denman's ice tongue from a
pinning point following its last major calving event are required to
simulate an acceleration comparable with observations. Given its bed
topography and the geological evidence that Denman Glacier has retreated
substantially in the past, its recent grounding line retreat and ice flow
acceleration suggest that it could be poised to make a significant
contribution to sea level in the near future.
Crystallographic analysis of temperate ice on Rhonegletscher, Swiss Alps
Authors: Hellmann Sebastian , Kerch Johanna , Weikusat Ilka , Bauder Andreas , Grab Melchior , Jouvet Guillaume , Schwikowski Margit , Maurer Hansruedi
Published: February 2021

Abstract. Crystal orientation fabric (COF) analysis provides information about the c-axis orientation of ice grains and the associated anisotropy and microstructural information about deformation and recrystallisation processes within the glacier. This information can be used to introduce modules that fully describe the microstructural anisotropy or at least direction-dependent enhancement factors for glacier modelling.
The COF was studied at an ice core that was obtained from the temperate Rhonegletscher, located in the central Swiss Alps.
Seven samples, extracted at depths between 2 and 79 m, were analysed with an automatic fabric analyser.
The COF analysis revealed conspicuous four-maxima patterns of the c-axis orientations at all depths.
Additional data, such as microstructural images, produced during the ice sample preparation process, were considered to interpret these patterns.
Furthermore, repeated high-precision global navigation satellite system (GNSS) surveying allowed the local glacier flow direction to be determined.
The relative movements of the individual surveying points indicated longitudinal compressive stresses parallel to the glacier flow.
Finally, numerical modelling of the ice flow permitted estimation of the local stress distribution. An integrated analysis of all the data sets provided indications and suggestions for the development of the four-maxima patterns.
The centroid of the four-maxima patterns of the individual core samples and the coinciding maximum eigenvector approximately align with the compressive stress directions obtained from numerical modelling with an exception for the deepest sample.
The clustering of the c axes in four maxima surrounding the predominant compressive stress direction is most likely the result of a fast migration recrystallisation.
This interpretation is supported by air bubble analysis of large-area scanning macroscope (LASM) images.
Our results indicate that COF studies, which have so far predominantly been performed on cold ice samples from the polar regions, can also provide valuable insights into the stress and strain rate distribution within temperate glaciers.
Aprendizagem da docência em uma escola do campo: ressignificações na trajetória de professores. DOI: 10.5212/OlharProfr.v.15i1.0008
Authors: Araújo Juliana Pereira de , Oliveira Rosa Maria Moraes Anunciato de
Published: February 2021

Tendo como fonte um trabalho de doutorado, procuramos compreender os aspectos sobre a aprendizagem da docência em uma escola do campo através do olhar dos sujeitos envolvidos. A revisão bibliográfica enfoca alguns conceitos como a oposição “urbano/rural” e “saberes docentes”. A partir da análise de narrativas de quatro professores que atuam em uma escola do campo situada em Araraquara-SP, procuramos evidenciar que para os professores vindos do ambiente urbano e que atuam no campo a docência se constrói inicialmente influenciada por sua experiência urbana e pela frágil elaboração de ideias sobre a história de marginalidade e de luta pela reforma agrária que marca o ruralismo pedagógico para os sujeitos da escola do campo. Nesse sentido, os docentes acionam conhecimentos superficiais para adaptação ao contexto, sem considerar várias experiências e elementos específicos dessas escolas que, quando vivenciados, potencializam processos de ressignificação profissional, mobilizando novas conformações dos conhecimentos docentes e impulsionando a constituição de outros saberes ainda pouco desenvolvidos. A docência nesse espaço precisa ser mapeada e melhor compreendida para enriquecimento da educação e concretização de um projeto nacional que possa integrar campo e cidade. Palavras-chave: Formação de professores. Educação do campo. Aprendizagem da docência.
Educação Sexual no ensino fundamental: o trabalho com alunos do 9º ano. DOI: 10.5212/OlharProfr.v.15i1.0012
Authors: Figueiredo Adda Daniela Lima , Silva Rayane Priscila
Published: February 2021

A sexualidade faz parte da vida de todas as pessoas e especificamente na adolescência acontece de maneira muito diferenciada e peculiar. Este trabalho objetivou promover a adolescentes, discentes do 9º ano do ensino fundamental de uma escola pública de Anápolis, a aquisição de conhecimentos sobre sexualidade, através da educação sexual. O estudo pautou sua revisão bibliográfica a partir dos autores: Abramovay et al. (2004); Biscoli (2005); Brandão e Heilborn (2006); Brêtas (2009); Junqueira (2009); Torres et al. (2008), dentre outros. Trata-se de uma pesquisa de abordagem qualitativa, que utilizou para coleta de informação, um questionário semiestruturado, aplicado em dois momentos, antes e após o trabalho com os adolescentes. Foram minitradas11 aulas, totalizando 15 horas de atividade. O grupo de estudo foi formado por adolescentes com idade entre 13 e 17 anos. A maioria dos adolescentes (83,3%) conversa sobre assuntos relacionados à sexualidade com amigos e obtêm informações na mídia (55,5%). 17% adolescentes afirmaram que já tiveram a primeira relação sexual, destes apenas 5,5% usou preservativo. Os métodos contraceptivos mais citados no pré-teste foram camisinha (72,2%) e a pílula anticoncepcional (33,3%). No pós-teste houve uma variedade na citação de métodos. Verificou-se com o pré-teste que as únicas doenças sexualmente transmissíveis citadas foram AIDS, Sífilis e Gonorreia. O trabalho comprovou a necessidade de atividades de educação sexual com turmas de 9º ano, em especial, de forma contínua, contribui para um desenvolvimento sexual saudável e a utilização do conhecimento para proteção pelos adolescentes.
Por uma educação do campo que contemple as parcerias nos processos formativos e as formas identitárias dos povos do campo. DOI: 10.5212/OlharProfr.v.15i1.0003
Authors: Rodrigues Priscila Andrade Magalhães
Published: February 2021

Este ensaio acadêmico constitui um esforço analítico sobre as questões que emergem sobre a produção em educação do e no campo, de modo a pensar uma proposta que contemple a construção de parcerias entre os envolvidos no movimento “por uma educação do campo” e que considere as formas identitárias dos povos do campo. Buscou-se, primeiramente, a partir da literatura dedicada ao tema, levantar as principais questões ligadas à educação do campo, em momento de grande efervescência de estudos e produção acadêmica sobre o assunto.  Em um segundo momento, buscou-se reconhecer o lugar da escola do campo na formação de docentes, e especialmente o estabelecimento de parcerias entre universidade, movimentos sociais, ONGs, e demais parceiros, e as escolas do campo, na tentativa de fomentar processos formativos que articulem teoria e prática, e que se atentem para as questões identitárias dos povos do campo e sua luta por reconhecimento social. Por fim, buscou-se olhar especialmente para a legislação e compreender como a questão da identidade dos povos do campo é tratada nestes textos, e trazer as contribuições analíticas para a construção da identidade dos povos do campo, na perspectiva de que toda análise cultural precisa considerar a complexidade da relação social entre os sujeitos.
Escolhas, percursos e trajetórias de formação: reflexões sobre a aprendizagem profissional da docência de professores iniciantes de Geografia
Authors: Bernardes Alessandra , Pereira Julio Emilio Diniz
Published: February 2021

Este artigo tem como objetivo central a compreensão dos processos de aprendizagem da docência por parte de professores iniciantes de Geografia da Educação Básica. Por meio da leitura e análise de questionários aplicados a nove professores, construímos um breve perfil dos respondentes e avançamos na discussão sobre: (1) os processos que conduziram a escolha pela licenciatura em Geografia como curso superior e (2) as relações entre formação acadêmico-profissional, iniciação e aprendizagem da docência. Quase totalidade dos professores, mesmo que de maneira crítica, reconhece as contribuições da formação na universidade para sua prática profissional. Entendem a formação como processo contínuo e não restrito aos saberes técnicos. Dessa maneira, valorizam a chamada “teoria” na formação acadêmica, porém afirmam sobre a necessidade de que as disciplinas que tenham esse caráter tomem a realidade escolar como referência para sua organização e desenvolvimento. Nos relatos desses professores, a entrada na escola desencadeou uma série de aprendizagens e reflexões em torno da própria prática e uma avaliação problematizadora da formação na universidade. Conhecer e analisar as trajetórias desses docentes nos trouxe uma série de elementos e indícios fundamentais para uma compreensão mais ampliada e complexificada dos processos de aprendizagem profissional da docência por parte dos professores iniciantes.
Nuevas tendencias en el proceso de formación y mentoría de profesores universitarios noveles en su primer año de docencia
Authors: Yot Domínguez Carmen , Mayor Ruiz Cristina
Published: February 2021

En el presente artículo se describe el programa de iniciación a la docencia de la Universidad de Sevilla a partir de la propia vivencia y se proponen líneas de mejora a cada una de sus fases, entre otras: crear y dinamizar una red social donde profesores principiantes y expertos puedan interactuar y comunicarse, incorporar el blog como herramienta útil para el desarrollo de un portfolio que ayude a la reflexión sobre la práctica pedagógica y utilizar los juegos y simulaciones como una estrategia o herramienta de aprendizaje más.
Dilemas de professores tutores iniciantes na educação a distância
Authors: Costa Sirlene Fabris , Rausch Rita Buzzi
Published: February 2021

Socializamos nesta produção algumas reflexões sobre os dilemas de professores tutores iniciantes na educação a distância, a EaD, que tem produzido modificações nas relações sociais e na forma de ensinar e de aprender na contemporaneidade. Diante destas mudanças, autores como Tardif (1997; 2002; 2008), Nóvoa (2009); Pimenta (1999); Schlemmer (2009; 2012), Moran (2011), Belloni (2008), entre outros contribuem na discussão desta nova modalidade de ensinar e de aprender. A investigação buscou respostas para a seguinte questão: quais os principais dilemas que se fazem presentes na EaD, nos dizeres de professores tutores iniciantes em cursos ofertados por  uma faculdade privada do estado de Santa Catarina? O objetivo geral foi compreender os dilemas de professores tutores iniciantes na EaD.  De abordagem qualitativa, realizamos entrevistas com nove professores tutores iniciantes. As categorias de análise foram definidas a posteriori, a partir das regularidades encontradas nas manifestações dos participantes. Os principais dilemas apresentados pelos professores iniciantes foram quanto à dificuldade de desenvolver um processo de mediação da aprendizagem dos alunos; a necessidade de conhecer o conteúdo de diversas disciplinas;  a não autonomia nos processos de avaliação da aprendizagem dos alunos; a pouca maturidade de alguns alunos; a falta de formação  continuada específica e a necessidade de constituir uma identidade profissional docente na EaD. Conclui-se que a pesquisa propiciou uma reavaliação dos dilemas presentes na EaD  e identificou a  necessidade de avanços no desenvolvimento profissional docente do professor tutor iniciante.
Buscando Caminhos - a integração do Ser ao Saber
Authors: Davantel Maria de Fátima
Published: February 2021

Percebe-se que a falta do hábito de ler tem contribuído para a produção de um discurso pobre, truncado e restrito. Neste artigo apresento minha busca de caminhos para se chegar à construção da contrapalavra através da leitura e sua exteriorização oral e/ou escrita. Dessa forma a leitura deverá ser trabalhada como fonte e instrumento criador de estruturas e inteligências que permitam o aluno, através do processo metsfórico, construir, reconstruir e ampliar conhecimentos, criando competências e tornando-se sujeito do conhecimento e da história. Além disso defende-se que a prática da conscientização de valores humanos universais, sob uma perspectiva filosófica, religiosa e cultural, através de texto-pretexto, criam e/ou ampliam o espírito de cooperação, de criatividade, de respeito às diferenças, de reverência e de amor pelos seres humanos, pois tais valores são fundamentais ao bom andamento do cotidiano escolar. Tal abordagem implica na certeza de que sem o resgate humano e o uso de metodologias alternativas PE impossível trabalhar a formação holística do ser.
Diferenças no saber em função do locus do aprender
Authors: Sales Luís Carlos
Published: February 2021

Tomando como referência o prédio escolar e suas implicações no processo de legitimação do saber, este trabalho faz uma análise dos processos semióticos, simbólicos e representacionais que levam uma pessoa a não legitimar o seu próprio saber, pelo fato de não ter estudado em espaços não legitimados socialmente ou que se distancie da configuração tradicional de prédio escolar.
Formação de professores: a didática como um processo reflexivo
Authors: De Carvalho Marlene Araújo
Published: February 2021

Este artigo objetiva discorrer sobre a didática como articuladora do processo de formação de professores e suas implicações na prática pedagógica dos sujeitos envolvidos em processo de desenvolvimento pessoal e profissional, tanto inicial quanto continuado.
Didática da UEPG: contribuições e repercussões
Authors: Althaus Maiza Taques Margraf
Published: February 2021

O presente artigo relata um estudo integrante da dissertação de mestrado defendida pela autoria onde buscou-se proceder a uma análise das contribuições da didática nos cursos de licenciatura da Universidade Estadual de Ponta Grossa, investigando também a sua repercussão na prática pedagógica dos professores de escola pública. O trabalho empreendido oportunizou compreender as dificuldades encontradas no desenvolvimento do trabalho pedagógico na disciplina de Didática, bem como os avanços necessários para o seu aprimoramento no contexto da formação de professores da UEPG. Parte também do suporte teórico de alguns autores que subsidiaram seu estudo, destacando alguns dos relatos das entrevistas realizadas com os interlocutores de sua pesquisa.
O paradigma emergente e a integração das novas tecnologias no Projeto Tv Escola
Authors: Vitkowski José Rogério
Published: February 2021

A proposta desse texto é apresentar nossas reflexões sobrea ainserção das novas tecnologias no espaço-tempo escolar, como o vídeo e a TV, através da análise crítica de uma modalidade de educação a distância, o programa TV Escola. É fruto de estudos e de experiências profissionais, que culminaram no trabalho apresentado como dissertação de Mestrado, em 1999, na Universidade de Ponta Grossa/Pr.
Incidental Durotomy in Lumbar Spine Surgery; Risk Factors, Complications, and Perioperative Management
Authors: Hassanzadeh Hamid , Bell Joshua , Bhatia Manminder , Puvanesarajah Varun
Published: February 2021

Incidental durotomy (ID) can occur in up to 14% of all lumbar spine surgeries. The risk of this complication is markedly higher among elderly patients with advanced spinal pathology. In addition, revision cases and other more invasive procedures increase the risk of ID. When unrepaired, IDs can increase the risk of developing meningitis and can lead to the formation of cerebrospinal fluid fistulas and pseudomeningoceles. Intraoperative recognition and repair are essential to ID management, although repair techniques vary considerably. Although primary suture repair is considered the “benchmark,” indirect repair alone has shown comparable outcomes. Given the concern for infection after ID, many have indicated for prolonged prophylactic antibiotic regimens. However, there is little clinical evidence that this is necessary after adequate repair. The addition of subfascial drains have been shown to promote wound healing and early ambulation, whereas no consensus on duration of indwelling drains exists and such management is largely case dependent. Early ambulation after surgery has not shown to be associated with increased risk of further ID complications and decreases rehabilitation time, length of stay, and risk of venous thromboembolism. However, there remains a role for conservation mobilization protocols in more severe cases where notable symptoms are observed.
Low Incidence of Asymptomatic Positive Patients Detected During Preoperative Testing for Total Joint Arthroplasty During the COVID-19 Pandemic
Authors: Zangrilli Julian , Hameed Daniel , Chisari Emanuele , Vannello Chris , Courtney P. Maxwell , Krueger Chad A.
Published: February 2021

Introduction:

Although the pause in elective surgery was necessary to preserve healthcare resources at the height of the novel coronavirus disease 2019 (COVID-19) pandemic, recent data have highlighted the worsening pain, decline in physical activity, and increase in anxiety among cancelled total hip and knee arthroplasty patients. The purpose of this study was to evaluate the effectiveness of our staged reopening protocol and the incidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among elective arthroplasty patients.

Methods:

We identified all elective hip and knee arthroplasty patients who underwent our universal COVID-19 testing protocol during our phased reopening between May 1, 2020, and July 21, 2020, at our institution. We recorded the SARS-CoV-2 test results of each patient along with their demographics, medical comorbidities, and symptoms at the time of testing. We followed each of these positive patients through their rescheduled cases and recorded any complications or potential SARS-CoV-2 healthcare exposures.

Results:

Of the 2,329 patients, we identified five patients (0.21%) with a reverse transcription-polymerase chain reaction--confirmed SARS-CoV-2 positive test, none with symptoms. All patients were successfully rescheduled and underwent their elective arthroplasty procedure within 6 weeks of their original surgery date. None of these patients experienced a perioperative complication at the time of their rescheduled arthroplasty procedure. No orthopaedic surgeon or staff member caring for these patients reported a positive SARS-CoV-2 test.

Conclusion:

Our phased reopening protocol with universal preoperative virus testing was safe and identified a low incidence of SARS-CoV-2 among asymptomatic, elective arthroplasty patients at our institution. With uncertainty regarding the trajectory of the COVID-19 pandemic, we hope that this research can guide future policy decisions regarding elective surgery.
Case – Spontaneous thrombosis of varix in childhood
Authors: Quisias Joshua , Chan Ernest Pang , Miao Timothy Liu , Ramirez Alvaro , Ross Ian , Wang Peter Zhan Tao
Published: February 2021

Not required
Case – Conservative management of deep penile skin infection post-three-piece penile prosthesis implantation
Authors: Alkandari Mohammad , Sadri Iman , Carrier Serge
Published: February 2021

Not required
Predominance of Cryptococcus neoformans Var. grubii in Ahvaz, Molecular Identification and Evaluation of Virulence Factors
Authors: Moslem Maryam , Fatahinia Mahnaz , Kiasat Neda , Zarei Mahmoudabadi Ali
Published: February 2021

Background: Cryptococcus neoformans is an encapsulated yeast pathogen with worldwide distribution, and the highest incidence of cryptococcosis was attributed to C. neoformans (var. grubii. The pathogenicity of Cryptococcus species is associated with several factors, including capsule and melanin production, growth at 37 ºC, and secretion of extracellular enzymes. Objectives: The present study aimed to isolate and identify Cryptococcus species from pigeon guano in Ahvaz, Iran and investigate important virulence factors in the isolates. Methods: Seventy-three isolates of C. neoformans var. grubii were identified based on classical and molecular microbiology methods. Capsule size was measured by the grow yeasts in the presence of 5% CO2. Specific media demonstrated the activity of extracellular enzymes (phospholipase, hemolysin, proteinase, esterase, urease, catalase, and gelatinase). Besides, melanin production was evaluated by the niger seed agar medium. Results: Two hundred and seventeen samples were examined for the presence of Cryptococcus over 165 days in Ahvaz. All tested isolates were contained capsules with variable sizes under 5% CO2 concentration. Moreover, 100% of isolates were produced extracellular enzymes (urease, hemolysin, and catalase), whereas no proteinase and gelatinase activities were observed among isolates. Furthermore, most isolates had phospholipase (93.1%) and esterase activities (86.3%). Also, melanin was produced by all of the isolates. Conclusions: Although two methods were used for recovery of Cryptococcus, only Cryptococcus was isolated from pigeon guano, and swabs from the cage walls were negative. Cryptococcus neoformans var. grubii was the only species from pigeon droppings from Ahvaz with more pathogenic factors. Owing to the high pathogenicity of the isolates, the frequency of the disease is expected to be higher.
In vitro antioxidant properties of 2-imino-benzimidazole and 1,3-thiazolo[3,2-a]benzimidazolone derivatives
Authors: Tomović Katarina , Mrmošanin Jelena , Yancheva Denitsa , Mavrova Anelia , Šmelcerović Andrija
Published: February 2021

Antioxidant properties of 2-[2-imino-5-nitro-3-(2-oxo-2-phenylethyl)-2,3-dihydro-1H-benzimidazol1-yl]-1-phenylethanone (compound 1) and 2-(4-fluorobenzylidene)-6-(phenylcarbonyl)[1,3]thiazolo[3,2a]benzimidazol-3(2H)-one (compound 2) were evaluated in vitro. Compounds 1 and 2 did not show significant radical scavenging activity. It has been suggested that antioxidant strategies should not be based on direct scavengers but rather on the potentiation of endogenous antioxidant defenses, or on the reduction of the sources of reactive species. Although a direct scavenging mechanism is missing, the assayed compounds (1 and 2) as evidenced inhibitors of xanthine oxidase and dipeptidyl peptidase-4 might act antioxidatively by employing other mechanisms.
Evaluating the loads on bulldozer undercarriage under longitudinal trim
Authors: Kirichenko Igor
Published: February 2021

Based on the air-wheel type machines simulation, a bulldozer mathematic model for all its operating modes has been worked out. Evaluation of loads on the bulldozer undercarriage under longitudinal trim has been considered as an example of possible implementing the potential of the mathematical model proposed.
Development of methodology for the industrial noise control in the case of the dedusting system of a foundry
Authors: Radičević Branko , Bjelić Mišo , Savković Mile , Zdravković Nebojša , Petrović Aleksandra
Published: February 2021

The article presents the methodology for industrial noise control in the case of the dedusting system of a foundry. The developed methodology starts from the fact that noise protection is possible at the source of noise itself, on the paths of sound waves, and at the place of reception. The model for noise prediction is the basis of the methodology for solving specific examples, which consists of two parts, the source model and the noise propagation model. The result of the model is a noise field, based on noise map creation time. The activities in the procedure of noise protection are defined on a concrete example, and their interdependence is determined. Designing a noise protection system involves taking into account several functional, technological, and other limitations. Based on the required noise reduction of 15 dB in the nearest residential unit, variant noise protection solutions have been formed. The selection of the final noise protection solution was based on the techno-economic analysis.
Erratum: Sudden death syndrome caused by cardiac tumor (2020, vol. 54, iss. 1, pp. 44-49)
Authors: Uredništvo U
Published: February 2021

There is an inaccuracy regarding DOI number for article that appeared on pages 44-49 of the year 2020, volume 54, issue 1 of Medicinski Časasopis [Dusica Petrovic Rodic, Marko Spasic, Biljana Popovska Jovicic, Danijela Milosev, Slobodanka Lj. Mitrovic. Sudden death syndrome caused by cardiac tumor. Med. čas. 2020; 54(1): 44-49. doi: 10.5937/mckg54-25981]. The DOI number should be in fact: doi:10.5937/mckg54-25547. The editors and publisher apologize for the inaccuracy.
Anatomical variants of circle of Willis
Authors: Milenković Aleksandra , Petrović Slađana , Nikolić Simon , Radović Branislava , Ilić Aleksandra , Gašić Miloš , Tomić Bojan
Published: February 2021

Introduction: The circle of Willis is the major source of collateral blood flow between the carotid and vertebrobasilar system. Its potential depends on the presence and size of arteries that vary greatly among normal individuals and therefore their adequate observation by a radiologist is necessary. Aim: Determine the type of the circle of Willis and their frequency. Determine the type, frequency and localization of anatomical variants of arteries, as well as their average diameter. Compare these variables according to the age and gender of the examinees. Material and methods: A retrospective study was performed at the Center for Radiology of the Clinical Center Nis during 2017. All subjects underwent CT or MR angiography according to a standard endocranial protocol. The anterior and posterior parts of the circle were specially observed, with an emphasis on the presence or absence of anatomical variants of the arteries, with the measurement of their diameter. The obtained data were classified into variants of the front or rear part of the ring as well as the type of ring according to integrity. The frequency of these variables and their comparison by sex and age were measured. Results: The research included 92 examinees. According to the configuration of the Willis arterial ring, the adult type was the most often represented (71.7%). The most common type in terms of integrity was partially complete. The most common anatomical variants obtained in our work was aplasia of AcoA (27.2%) and aplasia of one or both PCoA (21%). PcoA hypoplasia was occured in women with a frequency of 13.5% while in men it was not present. Conclusion: Adequate understanding of the morphology of the circle of Willis by radiological methods is a good guide for neurosurgical and radiological intervention procedures. In this way, potentially significant neurological complications and the risk of morbidity and mortality could be reduced.
The frequency of bucal and palatal impaction maxillary canines
Authors: Simić Sanja , Pavlović Jasna , Vukićević Vladanka , Vujačić Amila
Published: February 2021

Introduction: Maxillary canines are usually impacted teeth the second after third molar. Frequency of impacted maxillary canines is about 1 to 3% of population (in 85% of the cases palataly, and in 15% of the cases bucaly). The aim of this research was to find the frequency of bucal and palatal impacted maxillary canines in relation to sex and position of impacted tooth. Matherial and method: We analyzed three-dimensional computed tomography images (CBCT) of 64 examinees (aged 12 to 33 years) with 80 unerupted maxillary canines to plan the orthodontic therapy. Results: Among 64 examines with impactions, 80 impacted maxillary canines are diagnosed. The average age of all respondents in the survey is 16,3±4,3. Of 64 examinees in research 41(64.1%) were female which is significantly more important than the representation of male examinees whose number was 23(35.9%). Frequency of unilateral impactions of maxillary canines is three times higher 48 (75%) in comparison to bilateral impactions 16 (25%). Of total 80 impacted maxillary canines 19 (23.75%) were bucal impacted, 3 (2.75%) in the middle of alveolus and 58 (72.5%) palatally. With the bucal and palatal impaction usually was represented partially vertical impaction (70%); completely horizontal impaction (10%) was represented only in the palatal impaction. Conclusion: The analysis of CBCT images of maxilla shows a statistically significant frequency of partially vertical, unilateral and paltally localized impacted maxillary canines.
Diagnostic, prognostic and predictive parameters in prostate cancer
Authors: Mijović Milica , Nedeljković Vladica , Vukićević Danica , Mitić Nebojša , Đerković Branislav , Rašić Julijana , Premović Vesna
Published: February 2021

Prostate cancer (CP) is the most common malignancy in men in America, while it is the second most common in Europe. It is responsible for about 10% of cancer deaths in the same population. It is clinically manifested in various forms, from slow-growing to aggressive forms with pronounced metastatic potential. Diagnosis is made by a well-defined algorithm, which begins with the determination of serum prostate specific antigen values and ends with prostate biopsy as the "gold standard". Pathohistological diagnostic criterias are based on architectural, cytoplasmic, nuclear and characteristics of intraluminal structures, as well as periacinar cleftings, which are deffined as helpfull diagnostic criteria of undoubted importance. Prognostic and predictive parameters are classified into three categories. Some of them are an integral part of routine pathohistologicat report, while others are considered as the diagnostic process progresses. Modern knowledge introduces biomarkers into the everyday practice of personalized medicine, especially when is necessary to treat prostate cancer patients.
Redefining the concept of security from the aspect of modern imigrations
Authors: Ilijić Ljeposava , Vujičić Nikola
Published: February 2021

The paper analyses the contemporary security concept, with a special review of the security aspects of migrations. After the introduction, which primarily offers certain terminological concerns, and a review of the historical development of the term security, the paper points to the impact of globalization to national security, and the existence of interdependence of countries in modern age. For this reason, the paper especially emphasizes the importance of international organizations, as well as international documents, which present the basic guidelines for treatment of security risks modern society is facing. Although literature points to a series of security challenges and threats, it seems that in recent years the problem of mass migrations is a special problem, which was the reason for the other part of the paper to be dedicated to security aspects of migrations, in two basic directions: first, pointing to the principal problems appearing as the consequence of migrations, and second, presentation of the model for a response to the migration crisis. The last part of the paper is dedicated to conclusive contemplations.
General characteristics of the basic concept of terrorism
Authors: Petrović Dragana
Published: February 2021

Scientists trying to reach a consensus on the meaning of the term "terrorism" and how to deal with it have concluded that it is almost impossible to find a framework for a single generally accepted definition. When considering the conceptual determination of the word "terrorism", fragmented attitudes should serve as a warning that we are walking on thin ice where there is a collision of numerous definitions, a wealth of determinations with numerous discrepancies, contradictions, inaccuracies, and ambiguities. Some of the definitions are short and precise, and some implicitly explain what 'terrorism' means, some concepts coincide with those on which the content of the notion of terrorism is based, whereas some formulations are based on the delimitation of this criminal act in the field of national legislation. Ultimately, to summarize, at no point in history has this complex theme been discussed as it is today, while the results have been modest, even unsatisfactory. In short, progress in that sense has not been made. However, individual and collective scientific thought has contributed to defining the legal outlines of terrorism. Finally, its features have been determined significantly by international contracts and case law, which have clarified this concept, its main features. Based on this reference, as the author points out, significant differences exist between the aforementioned theoretical positions. The author says that a look at the level of substantial delimitation of concept terrorism will enable us to obtain interesting and applicable conclusions, which can be further used in explaining and scrutinizing both the characteristics and the specific content of the notion of terrorism, all in the function of looking for the most suitable model to fight against it.