bluuebunny/crossref_metadata_2025 huggingface dataset:
Mental health and illness of medical students and newly graduated doctors during the pandemic of SARS-Cov-2/COVID-19
Authors: Ferreira Lis Campos , Amorim Rívia Siqueira , Melo Campos Fellipe Matos , Cipolotti Rosana
Published: May 2021

Introduction: SARS-Cov-2 virus pandemic causes serious emotional consequences. It has occurred widespread medical courses suspension, and graduations were anticipated. Field hospitals, set up to treat patients with mild to moderate COVID-19, were the main workplaces of newly graduated doctors. Objective: To assess the impact of SARS-Cov-2/COVID-19 pandemic on mental health of medical interns and newly graduated doctors. Method: This is a cross-sectional study performed using a digital platform. Links to forms were sent in two moments: moment 1 (M1), at the beginning of the pandemic, in the first half of April/2020 and moment 2 (M2), after six months of pandemic, in the second half of September/2020. All students from the medical internship and all doctors graduated since 2018 from the three medical schools in Sergipe-NE-Brazil were invited. Results: 335 forms were answered in April and 148 in September. In M1 88.9% considered themselves exposed to excess of information about COVID-19, which was associated with anxiety symptoms (p = 0.04). Long family physical distance was also associated with these symptoms, as increased appetite (p = 0.01), feeling shortness of breath (p = 0.003) and sweating (p = 0.007). Fear of acquire COVID-19 was reported as intense by almost half of participants, and of transmitting by 85.7% in M1. In M2 41.2% reported the death of friends or relatives. Psychiatric illness was described by 38.5% and psychotropic drugs use by 30.1% in M1, especially those who lived alone (p = 0.03) and the single ones (p = 0.01). Alcohol intake was reported by 54.3%, and among doctors graduated in 2020 it increased from 50% in M1 to 85% in M2 (p = 0.04). Conclusion: The pandemic had a negative impact on the mental health of medical students and newly graduated doctors. Exposure to excessive COVID-19 information and family physical distance were associated to anxiety symptoms. Among doctors graduated in 2020, alcohol intake increased during pandemic evolution.
Physical properties of lactic acid bacteria influence the level of protection against influenza infection in mice
Authors: Watanabe Takumi , Hayashi Kyoko , Takahashi Isao , Ohwaki Makoto , Kan Tatsuhiko , Kawahara Toshio
Published: May 2021

We evaluated whether the water dispersibility of lactic acid bacteria (Enterococcus faecalis KH2) affects their efficacy. When cultured lactic acid bacteria are washed, heat-killed, and powdered, adhesion occurs between results in aggregation (non-treated lactic acid bacteria, n-LAB). However, dispersed lactic acid bacteria (d-LAB) with a lower number of aggregates can be prepared by treating them with a high-pressure homogenizer and adding an excipient during powdering. Mice were administered n-LAB or d-LAB Peyer’s patches in the small intestine were observed. Following n-LAB administration, a high amount of aggregated bacteria drifting in the intestinal mucosa was observed; meanwhile, d-LAB reached the Peyer’s patches and was absorbed into them. Evaluation in a mouse influenza virus infection model showed that d-LAB was more effective than n-LAB in the influenza yield of bronchoalveolar lavage fluids on day 3 post-infection and neutralizing antibody titers of sera and influenza virus-specific immunoglobulin A in the feces on day 14 post-infection. Therefore, the physical properties of lactic acid bacteria affect their efficacy; controlling their water dispersibility can improve their effectiveness.
Use of seat belts among public transport drivers in Tacna, Peru: Prevalence and risk factors
Authors: Miñan-Tapia Armando , Torres-Riveros Gloria S. , Choque-Vargas José , Aycachi-Incacoña Madeleyni , Flores-Valdez Neil , Vargas-Anahua Orlando , Mejia Christian R.
Published: May 2021

Introduction

There are individuals who still refuse to wear seat belts, despite its effectiveness in reducing morbidity and mortality in road traffic accidents. We aimed to determine the prevalence and risk factors according to the use of seat belts among public transport drivers in Tacna, Peru.

Methodology

This analytical transversal study was carried out among public transport drivers (buses and taxis) in a Peruvian city. Questionnaires were used to evaluate the general and occupational characteristics and the use of seat belts (observed). Descriptive statistics and risk factors were obtained, these latter through generalized linear models.

Results

Of the 460 drivers, 77% used their seat belts, with a difference in use depending on the type of public transport (p<0.001). In the multivariate model, the risk of not using the belt was associated with the following: older age (p<0.001), having complete studies (p<0.001), a higher level/category of driving license (3 categories had p<0.001), having a higher number of previous road traffic accidents (p = 0.011), and received medical attention in that accident (p<0.001), those who reported using a cell phone while driving (p = 0.005), if the co-driver’s belt had 3 anchorage points (p<0.001), and working for > 5 hours that day (p = 0.002). However, male drivers and those who had their belt with 3 anchorage points had greater use (both p<0.001).

Conclusions

One in five drivers did not use a seat belt, and important characteristics of those who did not comply with this traffic law were evaluated to generate control and intervention measures.
LINC00958 promotes proliferation, migration, invasion, and epithelial-mesenchymal transition of oesophageal squamous cell carcinoma cells
Authors: Wang Biqi , Tang Duo , Liu Zijia , Wang Qian , Xue Shan , Zhao Zijie , Feng Dongdong , Sheng Chao , Li Jintao , Zhou Zhixiang
Published: May 2021

Oesophageal cancer is one of the deadliest cancers in the world. Oesophageal squamous cell carcinoma (ESCC) is the most prevalent histological type of oesophageal cancer. Oesophageal cancer has a poor prognosis because of its invasiveness. Thus, it is especially important to seek effective treatment methods. Research indicates that long non-coding RNAs (lncRNAs) play a significant role in the occurrence and development of oesophageal cancer. The aim of this study was to describe the role of LINC00958 in ESCC. Bioinformatics and real-time quantitative polymerase chain reaction (RT-qPCR) methods were utilized to predict and verify the expression of LINC00958 in ESCC. Related functional experiments, including cell proliferation, migration and invasion, were performed. In addition, a western blot and a dual luciferase reporter gene experiment were used to study the detailed carcinogenic mechanism of LINC00958. The results indicated there was a high expression of LINC00958 in ESCC, which promoted proliferation, migration, invasion and Epithelial–Mesenchymal Transition (EMT) of ESCC cells, and this effect may be via regulating miR-510-5p.
Application of naïve Bayesian approach in detecting reproducible fatal collision locations on freeway
Authors: Kim Eui-Jin , Kwon Oh Hoon , Park Shin Hyoung , Kim Dong-Kyu , Chung Koohong
Published: May 2021

Detecting high-collision-concentration locations based solely on collision frequency may produce different results compared to those considering the severities of the collisions. In particular, it can lead government agencies focusing sites with a high collision frequency while neglecting those with a lower collision frequency but a higher percentage of injury and fatal collisions. This study developed systematic ways of detecting reproducible fatal collision locations (R) using the naïve Bayes approach and a continuous risk profile (CRP) that estimates the true collision risk by filtering out random noise in the data. The posterior probability of fatal collisions being reproducible at a location is estimated by the relationship between the spatial distribution of fatal-collision locations (i.e., likelihood) and the CRP (i.e., prior probability). The proposed method can be used to detect sites with the highest proxy measure of the posterior probability (PMP) of observing R. An empirical evaluation using 5-year traffic collision data from six routes in California shows that detecting R based on the PMP outperform those based on the SPF-based approaches or random selection, regardless of various conditions and parameters of the proposed method. This method only requires traffic collision and annual traffic volume data to estimate PMP that prioritize sites being R and the PMPs can be compared across multiple routes. Therefore, it helps government agencies prioritizing sites of multiple routes where the number of fatal collisions can be reduced, thus help them to save lives with limited resources of data collection.
Activation of the β-adrenergic receptor exacerbates lipopolysaccharide-induced wasting of skeletal muscle cells by increasing interleukin-6 production
Authors: Matsukawa Shino , Kai Shinichi , Seo Hideya , Suzuki Kengo , Fukuda Kazuhiko
Published: May 2021

The skeletal muscle mass has been shown to be affected by catecholamines, such as epinephrine (Epi), norepinephrine (NE), and isoproterenol (ISO). On the other hand, lipopolysaccharide (LPS), one of the causative substances of sepsis, induces muscle wasting via toll-like receptors expressed in skeletal muscle. Although catecholamines are frequently administered to critically ill patients, it is still incompletely understood how these drugs affect skeletal muscle during critical illness, including sepsis. Herein, we examined the direct effects of catecholamines on LPS-induced skeletal muscle wasting using the C2C12 myoblast cell line. Muscle wasting induced by catecholamines and/or LPS was analyzed by the use of the differentiated C2C12 myotubes, and its underlying mechanism was explored by immunoblotting analysis, quantitative reverse transcription polymerase chain reaction (qRT-PCR), enzyme-linked immunosorbent assay (ELISA), and the TransAM kit for p-65 NF-κB. Epi augmented myosin heavy chain (MHC) protein loss and reduction of the myotube diameter induced by LPS. LPS induced C/EBPδ protein, Atrogin-1 and inteleukin-6 (IL-6), and these responses were potentiated by Epi. An IL-6 inhibitor, LMT28, suppressed the potentiating effect of Epi on the LPS-induced responses. NF-κB activity was induced by LPS, but was not affected by Epi and recombinant IL-6, and the NF-κB inhibitor, Bay 11–7082, abolished Atrogin-1 mRNA expression induced by LPS with or without Epi. NE and ISO also potentiated LPS-induced IL-6 and Atroign-1 mRNA expression. Carvedilol, a nonselective β-adrenergic receptor antagonist, suppressed the facilitating effects of Epi on the Atrogin-1 mRNA induction by LPS, and abolished the effects of Epi on the MHC protein loss in the presence of LPS. It was concluded that Epi activates the β-adrenergic receptors in C2C12 myotubes and the IL-6-STAT3 pathway, leading to the augmentation of LPS-induced activation of the NF-κB- C/EBPδ-Atrogin-1 pathway and to the exacerbation of myotube wasting.
Respiratory syncytial virus M2-1 protein associates non-specifically with viral messenger RNA and with specific cellular messenger RNA transcripts
Authors: Braun Molly R. , Noton Sarah L. , Blanchard Emmeline L. , Shareef Afzaal , Santangelo Philip J. , Johnson W. Evan , Fearns Rachel
Published: May 2021

Respiratory syncytial virus (RSV) is a major cause of respiratory disease in infants and the elderly. RSV is a non-segmented negative strand RNA virus. The viral M2-1 protein plays a key role in viral transcription, serving as an elongation factor to enable synthesis of full-length mRNAs. M2-1 contains an unusual CCCH zinc-finger motif that is conserved in the related human metapneumovirus M2-1 protein and filovirus VP30 proteins. Previous biochemical studies have suggested that RSV M2-1 might bind to specific virus RNA sequences, such as the transcription gene end signals or poly A tails, but there was no clear consensus on what RSV sequences it binds. To determine if M2-1 binds to specific RSV RNA sequences during infection, we mapped points of M2-1:RNA interactions in RSV-infected cells at 8 and 18 hours post infection using crosslinking immunoprecipitation with RNA sequencing (CLIP-Seq). This analysis revealed that M2-1 interacts specifically with positive sense RSV RNA, but not negative sense genome RNA. It also showed that M2-1 makes contacts along the length of each viral mRNA, indicating that M2-1 functions as a component of the transcriptase complex, transiently associating with nascent mRNA being extruded from the polymerase. In addition, we found that M2-1 binds specific cellular mRNAs. In contrast to the situation with RSV mRNA, M2-1 binds discrete sites within cellular mRNAs, with a preference for A/U rich sequences. These results suggest that in addition to its previously described role in transcription elongation, M2-1 might have an additional role involving cellular RNA interactions.
Association of Spinal Alignment Correction With Patient-Reported Outcomes in Adult Cervical Deformity: Review of the Literature
Authors: Massaad Elie , Hadzipasic Muhamed , Kiapour Ali , Lak Asad M. , Shankar Ganesh , Zaidi Hasan A. , Hershman Stuart H. , Shin John H.
Published: May 2021

Objective: Adult cervical deformity (ACD) is a debilitating spinal condition that causes significant pain, neurologic dysfunction, and functional impairment. Surgery is often performed to correct cervical alignment, but the optimal amount of correction required to improve patient-reported outcomes (PROs) are not yet well-defined.Methods: A review of the literature was performed and Fisher z-transformation (Zr) was used to pool the correlation coefficients between alignment parameters and PROs. The strength of correlation was defined according to the following: poor (0 < r ≤ 0.3), fair (0.3 < r ≤ 0.5), moderate (0.5 < r ≤ 0.8), and strong (0.8 < r ≤ 1).Results: Increased C2–7 sagittal vertical axis was fairly associated with increased Neck Disability Index (NDI) (pooled Zr = 0.31; 95% confidence interval [CI], -0.03 to 0.58). Changes in T1 slope minus cervical lordosis poorly correlated with NDI (pooled Zr = -0.04; 95% CI, -0.23 to 0.30). Increased C7–S1 was poorly associated with worse EuroQoL 5-Dimension (pooled Zr = -0.22; 95% CI, -0.36 to -0.06). Correction of horizontal gaze did not correlate with legacy metrics. Modified Japanese Orthopedic Association correlated with C2-slope, C7–S1, and C2–S1.Conclusion: Spinal alignment parameters variably correlated with improved health-related quality of life and myelopathy after corrective surgery for ACD. Further studies evaluating legacy PROs, Patient-Reported Outcomes Measurement System, and ACD specific instruments are needed for further validation.
Vállalati tőkeszerkezet-politika : Empirikus elemzés a tőzsdei cégek tőkeszerkezet-választásáról 1995-2000 között
Authors: Balla Andrea
Published: May 2021

A szerző a magyar tőzsdei vállalatok példáján keresztül a leíró statisztika módszerével és ökonometriai modellekkel vizsgálja a tőkeszerkezetet befolyásoló tényezők körét, melyeket az eddigi hasonló tanulmányokhoz képest jelentősen kibővít. Fő következtetése az, hogy a rövid lejáratú források túlsúlya miatt tartósan és tömegesen sérül az eszközforrás lejárati illesztésének elve, ami hátrányosan befolyásolhatja a vállalatok növekedési lehetőségeit, ugyanakkor a különböző tőkestruktúra-teóriák egyszerre és egymást kiegészítve magyarázzák a vállalatok tőkestruktúra-döntéseit, melyek nem elsődlegesek a vállalati döntések sorában.
Versenyelőny-e a vállalati környezettudatosság?
Authors: Dudás Katalin
Published: May 2021

A cikk célja annak a kérdésnek a megválaszolása, hogy versenyelőnynek tekinthető-e a vállalati környezettudatosság. A szerző által áttekintett szakirodalmi elemzések, kutatási eredmények szerint az a vállalat tud előnyre szert tenni, amely környezettudatos lépéseit megfelelő módon teszi meg: a fenntartható fejlődés jegyében igyekszik kifejleszteni egyedi és másolhatatlan pozíciót létrehozó megkülönböztető kompetenciáit; amelyek áthatják a vállalat összes funkcióját, és kompatibilisek stratégiájával; ügyel az ezekhez szükséges erőforrások, képességek és képzettségek meglétére; olyan értékekre helyezi a hangsúlyt, amelyeket egy megfelelő nagyságú, elérhető fogyasztói szegmens ténylegesen értékel, és a költségeket meghaladó ár megfizetésével honorál.
ACG Clinical Guidelines: Prevention, Diagnosis, and Treatment of Clostridioides difficile Infections
Authors: Kelly Colleen R. , Fischer Monika , Allegretti Jessica R. , LaPlante Kerry , Stewart David B. , Limketkai Berkeley N. , Stollman Neil H.
Published: May 2021

Clostridioides difficile infection occurs when the bacterium produces toxin that causes diarrhea and inflammation of the colon. These guidelines indicate the preferred approach to the management of adults with C. difficile infection and represent the official practice recommendations of the American College of Gastroenterology. The scientific evidence for these guidelines was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation process. In instances where the evidence was not appropriate for Grading of Recommendations Assessment, Development, and Evaluation but there was consensus of significant clinical merit, key concept statements were developed using expert consensus. These guidelines are meant to be broadly applicable and should be viewed as the preferred, but not the only, approach to clinical scenarios.
Development of destructive thyroiditis and diabetes mellitus after three injections of pembrolizumab for skin melanoma
Authors: Glibka A. A. , Mel`nichenko G. A. , Mikhina M. S. , Mazurina N. V. , Kharkevich G. Yu.
Published: May 2021

The exponential rise in the use of immune checkpoint inhibitors (Ipilimumab, Nivolumab, Pembrolizumab, Atezolizumab, Durvalumab, and Avelumab) as the new standard for cancer treatment increase the incidence the immune-related adverse events due to immune activation. Endocrine immune-related adverse events are the third most commonly reported. Thyroid gland is most susceptible to autoimmune dysfunctions from immune checkpoint inhibitors and associated with the use of anti-PD-1 monoclonal antibodies. Hypophysitis develops more often during therapy with anti-CTLA-4 monoclonal antibodies. But such immune-related adverse events as diabetes mellitus, hypoparathyroidism are rare (about 1% of cases).We present a clinical case of the patient with skin melanoma who was prescribed therapy with immune checkpoints inhibitors (Pembrolizumab). Immune-related adverse events developed with damage to the endocrine organs after 3 Pembrolizumab injections. Of greatest interest is the development of two endocrine immune-related adverse events at once: destructive thyroiditis (with a short phase of thyrotoxicosis and subsequent persistent hypothyroidism) and diabetes mellitus. We tried to reflect the chronology of diseases and their features as fully as possible for endocrinologists, oncologists, therapists, family doctors and other medical doctors of related specialties.
Vitamin D deficiency in Russia: the first results of a registered, non-interventional study of the frequency of vitamin D deficiency and insufficiency in various geographic regions of the country
Authors: Avdeeva V. A. , Suplotova L. A. , Pigarova E. A. , Rozhinskaya L. Y. , Troshina E. A.
Published: May 2021

BACKGROUND. In Russian Federation, there are no large-scale cross-sectional multicenter epidemiological studies assessing the prevalence of vitamin D deficiency and insufficiency in different geographical latitudes. Insufficient solar insolation and inadequate vitamin D content in food dictate the need to study the epidemiological structure of low vitamin D status in Russia.AIM. To assess the incidence of vitamin D deficiency and insufficiency among the population living in the regions of the Russian Federation located at latitudes from 45 ° to 70 °.MATERIALS AND METHODS. The first stage of the Russian multicenter non-interventional registry study using the «crosssectional» method was carried out from March 2020 to May 2020.RESULTS. In regions that represent a geographically representative sample of regions of the Russian Federation with a high risk of developing low levels of vitamin D, it’s deficiency was noted in 55.96%, and the level of deficiency and insufficiency was recorded in 84.01%.CONCLUSION. Close attention to the wide scale of the problem of vitamin D deficiency and insufficiency in the Russian Federation will contribute to the progressive formation of various educational and preventive programs necessary to strengthen health and improve the quality of life of the population.
Nodular toxic goiter in children: clinical features, morphological variants
Authors: Ivannikova T. E. , Bezlepkina O. B. , Abdulhabirova F. M. , Abrosimov A. U. , Degtyarev M. V. , Zubkova N. A.
Published: May 2021

BACKGROUND: Toxic nodular goiter (TNG) is a rare disease in which the cause of hyperthyroidism is the presence of a node or nodes that autonomously secrete thyroid hormones. With children and adolescents this condition is extremely rare — in 5–7.5% of all cases of nodular goiter. Therapy of toxic nodular goiter is aimed at relieving the symptoms of hyperthyroidism taking into account the malignant potential of the nodular formation. In the available literature, there are no data on the clinical course, comparative results of cytological and histological data in patients with toxic nodular goiter, which debuted in their childhood.AIM: Analysis of the features of the clinical course, comparison of the results of cytological and histological studies of toxic nodular goiter in children and adolescents.MATERIALS AND METHODS: A retrospective, single-center study of 21 patients with single-nodular toxic goiter, hospitalized at the Endocrinology Research Centre in the period from January 2016 to December 2019.RESULTS: The mean age at the time of the survey was 13.9 years. Thirteen patients (65%) had manifest thyrotoxicosis, and seven (35%) had subclinical hyperthyroidism. More than half of children — 57.1% (n = 12) did not receive thyreostatic therapy. The cytological picture in 11 patients (61.1%) corresponded to benign changes (nodular colloid goiter or adenomatous goiter) — Bethesda II, in 4 patients — follicular tumor — Bethesda IV, in 4 children the study was not informative. 19 patients (90.5%) underwent surgical treatment (hemithyroidectomy). According to the results of histological examination, follicular adenoma was found in 44.4% of children with nodular toxic goiter with benign results of TAB (Bethesda II) and was found in 50% with revealing follicular neoplasia (Bethesda IV).CONCLUSION: For the first time in the Russian Federation was carried out a comparative analysis of the characteristics of cytological and histological studies in children with toxic nodular goiter. It is significant that only in 10.5% (n=2) cytological and morphological results were consistent. The choice of radical treatment tactics should take into account the high frequency of mismatches between histological and morphological studies.
The role of cytokines in the processes of adaptive integration of immune and neuroendocrine reactions of the human body
Authors: Troshina E. A.
Published: May 2021

The immune, endocrine and nervous systems are integrated due to the existence of reciprocal pathways for transmitting information about changes in their actual functional state. The main task of the brain is to receive, integrate and store information, and there is strong evidence that this also applies to information obtained through the body’s immune responses. It has been proven that the production of cytokines in the brain can be caused not only by peripheral immune stimulation, but also by the nerve cells themselves, stimulated by certain neurosensory signals. Evolutionarily preserved antihomeostatic mechanisms characteristic of specific diseases are the subject of further research, the results of which may be very important for the development of therapeutic strategies that would prevent the undesirable combined effects of immune and neuroendocrine mediators.
Scholars and Literati at the Old University of Aberdeen (1495–1800)
Authors: De la Croix David , Jay Hugo
Published: May 2021

This note is a summary description of the set of scholars and literati who taught at the Old University of Aberdeen, also called King’s College, from its inception in 1495 to the eve of the Industrial Revolution in 1800.
A presença da não neutralidade da ciência-tecnologia em literatura sobre a educação básica
Authors: Regina Hansen Taís , Marsango Daniel , Dos Santos Rosemar Ayres
Published: May 2021

A partir de meados do século XX, uma parcela da população passou a observar o desenvolvimento científico-tecnológico com um olhar mais crítico, surgindo o Movimento Ciência-Tecnologia-Sociedade que, ao passar dos anos, ganha força e adentra a educação. O ensino baseado nesse enfoque visa, entre outros aspectos, a formação de um cidadão crítico capaz de atuar positivamente na sociedade em que está inserido. Assim, a partir de temáticas relacionadas as vivências do estudante pretende-se que o mesmo seja capaz de perceber aspectos ligados ao desenvolvimento da Ciência-Tecnologia, bem como, sua não neutralidade, a fim de desmistificar diversas visões inadequadas referentes às mesmas. Dessa forma, investigamos como comparecem e quais encaminhamentos são dados às práticas educativas de perspectiva Ciência-Tecnologia-Sociedade na discussão da não neutralidade da Ciência-Tecnologia. O corpus de análise foi composto por trabalhos publicadas nos anais das edições dos; Encontro Nacional de Ensino de Química, Encontro Nacional de Ensino de Biologia e Encontro de Pesquisa em Ensino de Física, esse corpus foi submetido a análise textual discursiva, objetivando identificar e caracterizar a abordagem dada à dimensão da não neutralidade da Ciência-Tecnologia. Sintetizamos os resultados em: 1) Visões inadequadas sobre o desenvolvimento científico-tecnológico e a abordagem Ciência-Tecnologia-Sociedade; 2) Não neutralidade da Ciência-Tecnologia, superação dos mitos; 3) Participação social, postura crítico-reflexiva apresentadas após a implementação das práticas. Sinalizamos que ao trabalharmos com o enfoque Ciência-Tecnologia-Sociedade estamos promovendo ampliação das concepções de não neutralidade da Ciência-Tecnologia, assim como, promovendo a formação de sujeitos responsáveis e habilitados em intervir positivamente no meio em que estão inseridos na sociedade.
Competencias matemáticas: una mirada desde las estrategias de enseñanza en educación a distancia
Authors: Valderrama Martínez Daniel Alberto
Published: May 2021

El enfoque por competencias se constituye como una alternativa frente a la enseñanza tradicional centrada en la memorización y la mecanización, porque supone la combinación de conocimientos y el desarrollo de habilidades puestos en acción en una situación contextualizada. Dentro de las competencias transversales requeridas para el ejercicio profesional, las matemáticas desempeñan un papel importante al crear habilidades de pensamiento que permiten razonar de manera lógica y eficiente en resolución de problemas o situaciones cotidianas y tomar decisiones de forma eficiente. En educación a distancia, el desarrollo de competencias matemáticas está mediado por el uso de TIC, el deseo por aprender, el autoaprendizaje, el contexto y en el rol del docente, quien conducirá al estudiantado a la consecución de objetivos pertinentes para afrontar problemas.  En ese sentido, el presente artículo tiene como objetivo establecer algunos elementos centrados en las competencias matemáticas en educación a distancia que deben considerarse para identificar las estrategias empleadas por los docentes en una institución de educación superior se integran al enfoque por competencias. La metodología utilizada corresponde al enfoque cualitativo de tipo fenomenológico interpretativo, fundamentada en la aplicación de una entrevista semiestructurada. Los resultados muestran que es necesario realizar transformaciones en algunas estrategias docentes.
Análise de discursos de estudantes de ensino superior sobre radioatividade EM UMA PERSPECTIVAe suas relações Ciência-Tecnologia-Sociedade
Authors: Silva Brito Lourdilene , Nobre de Abreu Ferreira Luciana
Published: May 2021

Nesta pesquisa apresentamos a análise de perguntas formuladas por estudantes de ensino superior provenientes de diferentes cursos de Ciências da Natureza. A proposta foi desenvolvida em um curso de extensão universitária destinado ao ensino de radioatividade e estruturado segundo a abordagem Ciência-Tecnologia-Sociedade. Com o objetivo de promover reflexões para uma tomada de decisão, provocamos questionamentos nos estudantes a partir da exibição de vídeos concernentes à temática. As perguntas foram analisadas com base na linha francesa da análise de discurso, na perspectiva de Eni Orlandi, especialmente a Tipologia do Discurso. O estudo permitiu verificar indagações de cunho conceitual, científico, histórico, social, tecnológico e de saúde, as quais tenderam para discursos predominantemente autoritários. No entanto, também foram observados deslocamentos de sentido, configurando discursos que tendiam ao polêmico, o que demonstra um posicionamento desejável em ambientes de ensino por parte dos alunos. Os resultados apontam indícios de desenvolvimento do pensamento crítico dos estudantes, de modo que, ao produzirem múltiplos sentidos sobre o tema, ampliam a rede de conhecimentos e valores necessários ao processo de tomada de decisão.
Inclusión educativa de estudiantes con diversidad funcional visual en clases de ciencias naturales: un análisis desde la política pública
Authors: Castro Castillo Diana Carolina , Tuay Sigua Rosa Nidia
Published: May 2021

En los últimos años se han emprendido un conjunto de acciones que han posibilitado la inclusión en la escuela, de personas con diversidad funcional visual, ciegos, en los procesos de enseñanza y aprendizaje de las ciencias naturales, los cuales se dan como consecuencia de los movimientos dados a nivel mundial, desde la Declaración sobre la Educación para Todos (Unesco, 1990). En este orden de ideas, algunas instituciones de la ciudad de Bogotá, Colombia, han sido dotadas de recursos físicos y humanos para atender estas comunidades, sin embargo, se hace necesario, mayor reflexión y propuestas teóricas sobre las implicaciones que tiene el abordaje de los objetos de conocimiento de las ciencias y cómo estos deben ser enseñados desde el reconocimiento de las capacidades sensoriales de los estudiantes. En este artículo de investigación se realiza un análisis de algunos documentos de política pública a nivel nacional e internacional relacionados con la enseñanza de la ciencia y su perspectiva de inclusión para estudiantes con diversidad funcional visual y documentos particulares sobre la inclusión educativa.  El estudio se enmarca en una tesis del Doctorado Interinstitucional en Educación de la Universidad Pedagógica Nacional.
XXIII Semana de la Enseñanza de La Física. 200 años del Electromagnetismo.
Authors: Mancera Martínez Brian Mateo , Salamanca Bernal Julián Andrés , Hurtado Alejandro
Published: May 2021

Evento desarrollado del 23 al 27 de noviembre de 2020, en el Proyecto Curricular de Licenciatura en Física, de la Facultad de Ciencias y Educación. Universidad Distrital Francisco José de Caldas, Bogotá, Colombia.

A comienzos de 1820 el físico danés Hans Christian Ørsted descubrió experimentalmente la relación existente entre el magnetismo y la electricidad, publicando su descubrimiento en un corto artículo titulado: Experimenta circa effectum conflictus electrici in acum magneticam. Dando origen al electromagnetismo y a una serie de trabajos de diversos científicos, que culminaron con la unificación, lograda por James Clerk Maxwell, de la electricidad, el magnetismo y la luz como diversas manifestaciones de un mismo fenómeno físico. Trabajo que fue publicado bajo el título de: A Dynamical Theory of the Electromagnetic Field. Se cumplen así 200 años de un descubrimiento que cambiaría la concepción física de la época y potenciaría un desarrollo que aún hoy día continúa.
Los efectos de la pandemia en las universidades y su relevancia en los estudios comparados internacionales
Authors: Arenas Jorge
Published: May 2021

La vulnerabilidad de las sociedades a consecuencia de la intervención de los humanos en los ecosistemas planetarios, junto con los procesos de la globalización que expanden los impactos de fenómenos  locales al resto del mundo, han sido descritos de forma lúcida por el sociólogo alemán Ulrich Beck, quien en su obra clásica “La Sociedad del Riesgo” (1998) advertía ya de la permanente condición de peligro que enfrentan las sociedades modernas, como resultado de la aplicación intensiva del conocimiento en el dominio de la naturaleza. De alguna forma, las previsiones de este autor se tornaron ominosa realidad tras la alerta de la Organización Mundial de la Salud (OMS), el 11 de marzo de 2020, en el sentido de que la humanidad enfrentaba una pandemia de alcances imprevistos como la del COVID-19.
Entrevista con Mabel Alicia Rodriguez
Authors: Vizcaíno Arevalo Diego Fabian
Published: May 2021

Mabel Alicia Rodriguez: Licenciada en Ciencias Matemáticas 1991 y Doctora de la Universidad de Buenos Aires, área Ciencias Matemáticas, 1997. Categoría 1 en el Programa de Incentivos. Profesora Asociada regular de la Universidad Nacional de General Sarmiento a cargo de la Dirección de la Especialización en Didáctica de las Ciencias (con orientación Matemática, Física o Química). Dirigió el Profesorado de Matemática desde 2019 a 2021. Fue Coordinadora de Investigación del Instituto del Desarrollo Humano (2014-2018). Fue Profesora titular regular de la Universidad Nacional de Tierra del Fuego (2014-2019).
Especie nueva de Weinmannia (Cunoniaceae) de los Bosques andinos altimontanos de La Paz, Bolivia
Authors: Fuentes Alfredo F.
Published: May 2021

Weinmannia epicae is described and illustrated. It grows in Andean high-montane forests of the Yungas region in the department of La Paz, northwestern Bolivia, between 2900 and 3300 m. It differs from other morphologically similar species as W. cundinamarcensis, W. haenkeana and W. pubescens by having the maximum number of leaflets pairs usually between 10 to 14, medial leaflets of 1.3 to 2.3 cm, with more or less rough surface and undersurfaces with hirsute to hirsute-villous indument, and mature capsules villous-pubescent of 5-7 × 1.8-2.7 mm, conspicuously pedicellated. The differences with morphological similar species are pointed out, and information on their geographical distribution, ecology, phenology and the assessment of conservation status according to IUCN criteria are provided.
Synthesis of (PVA/PEG: ZnO and Co3O4) Nanocomposites: Characterization and Gamma Ray Studies
Authors: Jassim Hanan H. , Hashim Fouad Sh.
Published: May 2021

Polymer blend (PVA/PEG) and its nanocomposites with constant ZnO and different ratios of Co3O4 NPs films synthesized using solution cast technique. The obtained products were identified by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). Optical characteristics have been studied by UV-visible spectroscopy. FT-IR spectra confirmed of the produce the functional groups present in polymer nanocomposite systems. XRD analysis confirmed the formation nanocomposite films more crystalline from the polymeric matrix. SEM showed a powerful dispersion of ZnO and Co3O4 NPs on the surface of the polymeric matrix. The D.C electrical conductivity of the polymeric system (PVA/PEG) increases after addition of and Co3O4 NPs for all temperatures under test. D.C measurements indicate that all films having one activation energy, and that its value increases with the increase in the percentage of addition. The A.C electrical properties showed that the dielectric constant and dielectric loss for all films decreases with the increase of the electric field frequency, and that its values increase with the increasing of the wt.% of Co3O4 NPs. The (PVA/PEG) and its nanocomposite with ZnO and different wt.% of Co3O4 films have good linear attenuation coefficients for gamma ray radiation.
“Stay home, be safe, and be kind”: University of Auckland’s Italian
course goes online in a week
Authors: Martelli Barbara
Published: May 2021

On March 23rd, at the University of Auckland (New Zealand), all lectures
were suspended for a week. During this time, both students and staff made a
considerable effort to prepare the online delivery of courses. In this
chapter we discuss the impact of COVID-19 on the Italian beginners courses
offered in Semester 1. With no certainty of when the campus would reopen,
and with the well-being of students always considered as a priority, the
courses were quickly adapted for distance learning. This change involved
multiple aspects and the experience gained, denoted by urgency and
flexibility, proving to be a precious resource to face the second semester
and, above all, a less predictable and more frightening future; in which not
only safety and adaptability, but kindness and mutual respect, should also
be the keywords. Designing blended, easily migratable online courses that
make use of both technology and up-to-date approaches to language teaching
has emerged as a viable strategy for an uncertain future.
Wprowadzenie
Authors: Churski Paweł
Published: May 2021

Przedstawiamy Państwu nr 53 czasopisma „Rozwój Regionalny i Polityka Regionalna” przygotowywanego przez Wydział Geografii Społeczno-Ekonomicznej i Gospodarki Przestrzennej Uniwersytetu im. Adama Mickiewicza w Poznaniu. Jest to zbiór ośmiu artykułów opracowanych przez autorów z ośrodków naukowych z całej Polski w formule Varia. Trzy z nich zostały napisane przez uczestników konferencji „Rewitalizacja miast i odnowa wsi”, która odbyła się w dniach 22–23 października 2020 r. na Wydziale Geografii Społeczno-Ekonomicznej i Gospodarki Przestrzennej UAM i była trzecią edycją cyklu Dni Planisty organizowanego przez Akademickie Koło Naukowe Gospodarki Przestrzennej, bardzo prężnie działające przy naszym wydziale.
Análise da dinâmica e dependência espaciais da produção de milho no território rural “Sertão Ocidental” sergipano
Authors: Silva Damaris Santos da , Silva Marcos Aurélio Santos da , Carvalho Hélio Wilson Lemos de , Dompieri Márcia Helena Galina , Cuenca Manuel Alberto Gutierrez
Published: May 2021

O presente trabalho emprega análise exploratória espacial para investigar a dinâmica e a dependência espaciais da produção de milho no Território Rural Sertão Ocidental (TRSO) sergipano. Foram calculadas as autocorrelações espaciais global e local pelos índices Moran e LISA a partir das seguintes variáveis agregadas por município: área plantada (ha), quantidade produzida (t) e rendimento médio (kg/ha) para o período de 1974 a 2016. Também foram analisados os baricentros para cada ano e variável de forma a identificar possíveis deslocamentos da produção. Conclui-se que houve deslocamento da produção e da área plantada no sentido do TRSO, e que rendimentos elevados sempre se mantiveram localizados no TRSO. Todas as três variáveis apresentaram forte dependência espacial demonstrada pela estatística I de Moran, e heterogeneidade espacial local detectada pelo índice LISA, principalmente para a variável rendimento.
Avaliação das características poliméricas do biofilme do resíduo de melancia
Authors: De Menezes Filho Antonio Carlos Pereira , Souza João Carlos Perbone de , Castro Carlos Frederico de Souza
Published: May 2021

O trabalho teve por objetivo avaliar as características poliméricas do biofilme a partir do resíduo do fruto de Citrullus lanatus. O biopolímero foi produzido a partir de uma suspensão aquosa farinácea do albedo e avaliado quanto às características físico-químicas, antioxidantes, mecânicas e por análises em microscopia óptica e eletrônica por varredura. O biofilme do resíduo de melancia apresentou importantes resultados nos testes físico-químicos, mecânicos e de atividade antioxidante, importante quantitativo de fenóis totais e boa eficiência nas características estruturais. Este novo biopolímero a partir do resíduo de melancia poderá ser aplicado no desenvolvimento de embalagens biodegradáveis, bem como no revestimento de salames defumados na indústria alimentícia.
The geometric average of curl-free fields in periodic geometries
Authors: Poelstra Klaas Hendrik , Schweizer Ben , Urban Maik
Published: May 2021

In periodic homogenization problems, one
considers a sequence

(

u
η

)

η

{(u^{\eta})_{\eta}}

of solutions to periodic
problems and derives a homogenized equation for an effective
quantity

u
^

{\hat{u}}

. In many applications,

u
^

{\hat{u}}

is the weak
limit of

(

u
η

)

η

{(u^{\eta})_{\eta}}

, but in some applications

u
^

{\hat{u}}

must
be defined differently. In the homogenization of Maxwell’s
equations in periodic media, the effective magnetic field is
given by the geometric average of the two-scale limit. The notion
of a geometric average has been introduced in [G. Bouchitté, C. Bourel and D. Felbacq,
Homogenization of the 3D Maxwell system near resonances and artificial magnetism,
C. R. Math. Acad. Sci. Paris 347 2009, 9–10, 571–576]; it associates to a
curl-free field

Y
∖

Σ
¯

→

ℝ
3

{Y\setminus\overline{\Sigma}\to\mathbb{R}^{3}}

, where
Y is the periodicity cell and Σ an inclusion, a vector
in

ℝ
3

{\mathbb{R}^{3}}

. In this article, we extend previous definitions to
more general inclusions, in particular inclusions that are not
compactly supported in the periodicity cell. The physical
relevance of the geometric average is demonstrated by various
results, e.g., a continuity property of limits of tangential traces.
Multiplicity and Concentration of Solutions for Kirchhoff Equations with Magnetic Field
Authors: Ji Chao , Rădulescu Vicenţiu D.
Published: May 2021

In this paper, we study the following nonlinear magnetic Kirchhoff equation:

{

-

(

a
⁢

ϵ
2

+

b
⁢
ϵ
⁢

[
u
]

A
/
ϵ

2

)

⁢

Δ

A
/
ϵ

⁢
u

+

V
⁢

(
x
)

⁢
u

=

f
⁢

(

|
u
|

2

)

⁢
u

in 
⁢

ℝ
3

,

u
∈

H
1

⁢

(

ℝ
3

,
ℂ
)

,

\left\{\begin{aligned} &\displaystyle{-}(a\epsilon^{2}+b\epsilon[u]_{A/% \epsilon}^{2})\Delta_{A/\epsilon}u+V(x)u=f(\lvert u\rvert^{2})u&&\displaystyle% \phantom{}\text{in }\mathbb{R}^{3},\\ &\displaystyle u\in H^{1}(\mathbb{R}^{3},\mathbb{C}),\end{aligned}\right.

where

ϵ
>
0

{\epsilon>0}

,

a
,
b

>
0

{a,b>0}

are constants,

V
:

ℝ
3

→
ℝ

{V:\mathbb{R}^{3}\rightarrow\mathbb{R}}

and

A
:

ℝ
3

→

ℝ
3

{A:\mathbb{R}^{3}\rightarrow\mathbb{R}^{3}}

are continuous potentials, and

Δ
A

⁢
u

{\Delta_{A}u}

is the magnetic Laplace operator. Under a local assumption on the potential V, by combining variational methods, a penalization technique and the Ljusternik–Schnirelmann theory, we prove multiplicity properties of solutions and concentration phenomena for ϵ small. In this problem, the function f is only continuous, which allows to consider larger classes of nonlinearities in the reaction.
Dimensionally Consistent Preconditioning for Saddle-Point Problems
Authors: Herzog Roland
Published: May 2021

The preconditioned iterative solution of large-scale saddle-point systems is of great importance in numerous application areas, many of them involving partial differential equations.
Robustness with respect to certain problem parameters is often a concern, and it can be addressed by identifying proper scalings of preconditioner building blocks.
In this paper, we consider a new perspective to finding effective and robust preconditioners.
Our approach is based on the consideration of the natural physical units underlying the respective saddle-point problem.
This point of view, which we refer to as dimensional consistency, suggests a natural combination of the parameters intrinsic to the problem.
It turns out that the scaling obtained in this way leads to robustness with respect to problem parameters in many relevant cases.
As a consequence, we advertise dimensional consistency based preconditioning as a new and systematic way to designing parameter robust preconditoners for saddle-point systems arising from models for physical phenomena.
Eisenstein series and the top degree cohomology of arithmetic subgroups of SL
n
/ℚ
Authors: Schwermer Joachim
Published: May 2021

The cohomology

H
*

⁢

(
Γ
,
E
)

{H^{*}(\Gamma,E)}

of a torsion-free arithmetic subgroup Γ of the special linear

ℚ

{\mathbb{Q}}

-group

𝖦
=

SL
n

{\mathsf{G}={\mathrm{SL}}_{n}}

may be interpreted in terms of the automorphic spectrum of Γ. Within this framework, there is a decomposition of the cohomology into the cuspidal cohomology
and the Eisenstein cohomology.
The latter space is decomposed according to the
classes

{
𝖯
}

{\{\mathsf{P}\}}

of associate proper parabolic

ℚ

{\mathbb{Q}}

-subgroups of

𝖦

{\mathsf{G}}

. Each summand

H

{
P
}

*

⁢

(
Γ
,
E
)

{H^{*}_{\mathrm{\{P\}}}(\Gamma,E)}

is built up by Eisenstein series (or residues of such) attached to cuspidal automorphic forms
on the Levi components of elements in

{
𝖯
}

{\{\mathsf{P}\}}

.

The cohomology

H
*

⁢

(
Γ
,
E
)

{H^{*}(\Gamma,E)}

vanishes above the degree given by the cohomological dimension

cd
⁢

(
Γ
)

=

1
2

⁢
n
⁢

(

n
-
1

)

{\mathrm{cd}(\Gamma)=\frac{1}{2}n(n-1)}

.
We are concerned with the internal structure of the cohomology in this top degree. On the one hand, we explicitly describe the associate classes

{
𝖯
}

{\{\mathsf{P}\}}

for which the corresponding summand

H

{
𝖯
}

cd
⁢

(
Γ
)

⁢

(
Γ
,
E
)

{H^{\mathrm{cd}(\Gamma)}_{\mathrm{\{\mathsf{P}\}}}(\Gamma,E)}

vanishes. On the other hand, in the remaining cases of associate classes
we construct various families of non-vanishing Eisenstein cohomology classes which span

H

{
𝖰
}

cd
⁢

(
Γ
)

⁢

(
Γ
,
ℂ
)

{H^{\mathrm{cd}(\Gamma)}_{\mathrm{\{\mathsf{Q}\}}}(\Gamma,\mathbb{C})}

.

Finally, in the case of a principal congruence subgroup

Γ
⁢

(
q
)

{\Gamma(q)}

,

q
=

p
ν

>
5

{q=p^{\nu}>5}

,

p
≥
3

{p\geq 3}

a prime, we give lower bounds for the size of these spaces. In addition, for certain associate classes

{
𝖰
}

{\{\mathsf{Q}\}}

, there is a precise formula for their dimension.
Modification of sodium bicarbonate and its effect on foaming behavior of polypropylene
Authors: Luo Dan , Pei Xianglin , Fu Hai , Yang Xin , Long Siyu , Zhang Linyu , Gong Wei
Published: May 2021

As a potential physical blowing agent, sodium bicarbonate (SB) is environmentally friendly and low in cost, but its low decomposition temperature cannot meet the requirements of polyolefin foam materials. Herein, for enhancing the thermal properties of SB, a modified way was offered to fabricate various SB-based capsules via suspension polymerization. As the modified SB-based capsules, epoxy resin (EP) accompanied with several organic acids was successfully coated on the surface of SB, serving as heat-insulation layer of SB. Various physicochemical characterizations provided reliable evidences for the good coating effect, and the thermal performance of the modified SB was improved. Further, the composite SB capsules were applied for the foaming of polypropylene (PP), and the foaming behavior of the SB-based capsules in PP was significantly improved, with more uniform distribution, smaller cell diameter, and higher cell density. In all, this work fully proved that the coated shells enhanced the thermal properties of SB, and the modified SB capsules significantly improved the foaming quality of foamed PP.