bluuebunny/crossref_metadata_2025 huggingface dataset:
Oleuropein modulates over-proliferation
of keratinocytes in mice with imiquimodmediated
psoriasis and inhibits differentiation of TH17 cells
through the JAK3/STAT3 axis
Authors: Shi Quan , He Qi , Chen Weiming , Long Jianwen , Zhang Bo
Published: March 2021

Introduction

Oleuropein (OLP) is polyphenol obtained from olive oil; it is proved in Chinese traditional medicine for its use in disorders including autoimmune and inflammatory disorders. Psoriasis (PSR) is an autoimmune and inflammatory disorder triggered by T-helper-17 (Th17) cells.

Material and methods

We developed an imiquimod (IMQ)-mediated PSR model in mice to study the anti-inflammatory role of OLP in psoriasis. The mice were given 50 mg/kg and 100 mg/kg dose of OLP. Histology was done to assess the inflammation of lesions. Western blot analysis was done for JAK3/STAT3 in isolated T cells, expression of RORgt was done by RT-PCR. The In silico molecular docking studies were done for interaction of OLP with target protein STAT3 and JAK3.

Results

Treatment of OLP attenuated proliferation in IMQ-mediated keratinocytes, improved infiltration of CD3+ cells in the skin lesions and in CD4+ and CD8+ T cells and also ameliorated the levels of cytokines. In in vitro studies in isolated T cells, OLP blocked the differentiation of Th17 cells and also the levels of IL-17 and the JAK3/STAT3 pathway. The in silico docking showed that OLP had potential binding affinity with JAK3 and STAT3 which was parallel to in vivo and in vitro findings.

Conclusions

OLP ameliorates psoriasis skin lesions by blocking Th17-mediated inflammation. OLP may be an interesting molecule for treating autoimmunity in psoriasis.
Important role of long non-coding RNA UBE2R2-AS1 in diabetes-induced renal injury
Authors: Chen Chuanqi , Yan Yanqiong , Luo Qianjun , Li Sufen
Published: March 2021

Introduction

The present study examined the effects and mechanisms underlying long non-coding RNA (lncRNA) UBE2R2-AS1 in diabetes-induced renal injury.

Material and methods

High glucose was used to imitate diabetes-induced renal injury in a cell model. Cell apoptosis rate was measured using flow cytometry, tumour necrosis factor-a (TNF-a) and interleukin-6 (IL-6) concentrations were evaluated using ELISA, and relative protein expression and amount were measured using western blot (WB) analysis and immunofluorescence, respectively. Correlations between lncRNA UBE2R2-AS1, miRNA-877-3p and TLR4 were analysed using the luciferase reporter assay.

Results

Cell apoptosis rate and TNF-a and IL-6 concentrations were significantly higher (p < 0.001) in the high glucose (model) group compared with those of the Control group (CG) group. Following shRNA knockdown of lncRNA UBE2R2-AS1, the cell apoptosis rate and TNF-a and IL-6 concentrations were significantly lower (p < 0.001, respectively) compared with those of the model group. However, under high-glucose conditions, shRNA knockdown of UBE2R2-AS1 and miRNA-877-3p significantly increased (p < 0.001) the cell apoptosis rate as well as TNF-a and IL-6 concentrations compared with the shRNA UBE2R2-AS1 knockdown group. WB and immunofluorescence analysis showed that toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88)/nuclear factor kB (p65) (NF-kB(p65)) pathway proteins were significantly stimulated in the model group compared with those in the CG, whereas shRNA transfection with miRNA-877-3p stimulation suppressed the TLR4/MyD88/NF-kB(p65) pathway.

Conclusions

Knockdown of lncRNA UBE2R2-AS1 improves diabetes-induced renal injury via regulation of the miRNA-877-3p/TLR4 axis in vitro.
Vitamin D ameliorated endothelial cell damage induced by diabetes via regulation of lncRNA MEG3 in human umbilical vein endothelial cells
Authors: Wei Hua , Zhang Qiongfang , Li Jun , Yang Jing , Huang Bin , Huang Chun-chun , Wang Ying-chuan , Hu Jing-qian , Wei Xi
Published: March 2021

Introduction

The purpose of this study was to investigate long non-coding RNA (lncRNA) maternally expressed gene 3 (MEG3) effects in vitamin D (Vit. D) treatment in endothelial cell damage induced by diabetes.

Material and methods

We used human umbilical vein endothelial cells (HUVECs) as a research objective in our study and used high glucose in a diabetic cell model. We evaluated cell apoptosis by flow cytometry, inflammatory factors (IL-6, IL-1β and TNF-α) concentrations by ELISA assay, relative gene and protein expression by RT-qPCR and WB assay, and NF-κB(p65) nuclear volume by cellular immunofluorescence.

Results

Compared with the NC (normal control) group, the cell apoptosis rate was significantly increased, inflammatory factor (IL-6, IL-1β and TNF-α) concentrations were significantly up-regulated, lncRNA MEG3 gene expression was significantly depressed, Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88) and nuclear factor B p65 (NF-κB(p65)) gene and protein expression levels were significantly increased and NF-κB(p65) nuclear volume was significantly up-regulated (p < 0.001, respectively). With Vit. D supplementation, compared with the Model group, Vit. D improved endothelial cell damage induced by diabetes, while lncRNA MEG3 was significantly increased and the TLR4/MyD88/NF-κB(p65) pathway was significantly depressed dose-dependently (all p < 0.05). With sh-MEG3 transfection, the Vit. D treatment effects were significantly reduced.

Conclusions

Vit. D improved endothelial cell damage induced by diabetes via lncRNA MEG3 up-regulation in vitro study.
The mechanism of treatment of multiple myeloma
with metformin by way of metabolism
Authors: Song Yanyan , Chen Song , Xiang Wei , Xiao Muran , Xiao Hui
Published: March 2021

Introduction

Multiple myeloma (MM) is a malignant hematologic tumor. Although many new drugs are currently found to significantly improve the median survival, MM is still not curable due partly to drug resistance recurrence. Epidemiological studies have shown that patients with type 2 diabetes have a high risk of malignancy, and patients’ treatment with metformin could reduce the risk of cancer as well as associated mortality.

Material and methods

We used chemotherapeutics – melphalan combined with metformin or the single drug – to treat RPMI8226 cells and used a series of tests to detect the drug sensitivity, apoptotic rate, DNA damage and the concentration of ATP. SPSS 17.0 was used to analyze the data.

Results

The inhibitory effect of melphalan on RPMI8226 cells was significantly increased after metformin was added (p < 0.05), and the inhibitory effect was enhanced with the increasing concentration of melphalan. The comet assay showed that metformin increased melphalan-induced DNA damage and increased the apoptotic rate from 12.7 ±2.8% to 18.8 ±1.5% (p < 0.05). In the ATP concentration test, the concentration of ATP in the tumor cells was significantly decreased from 0.42 ±0.01 µmol/l to 0.08 ±0.02 µmol/l (p < 0.05).

Conclusions

Metformin can promote DNA damage induced by melphalan and decrease the concentration of ATP in the process of repairing DNA damage to hinder the anti-apoptotic process of tumor cells, which showed the pesticide effect of the enhanced sensitivity of multiple myeloma cells to melphalan.
Gastrointestinal haemorrhage in extracorporeal membrane oxygenation: insights from the national inpatient sample
Authors: Solanki Shantanu , Haq Khwaja , Jolly George , Chakinala Raja Chandra , Khan Muhammad Ali , Patel Neil , Bhurwal Abhishek , Haq Khwaja , Nabors Christopher , Ganatra Sarju , Aronow Wilbert
Published: March 2021

Introduction

Extracorporeal membrane oxygenation (ECMO) is associated with gastrointestinal haemorrhage (GIH), which may result from coagulo­pathy, systemic inflammation, reduced gastric perfusion, and arteriovenous malformation from non-pulsatile blood flow. Data are limited regarding the burden of this complication in the United States.

Material and methods

We analysed the National Inpatient Sample (NIS) database for the years 2007 to 2011 to identify hospitalisations in which an ECMO procedure was performed. Hospitalizations complicated by GIH in this cohort were then identified by relevant codes.

Results

Between 2007 and 2011, ECMO hospitalisations increased from 1869 to 3799 (p < 0.01). The proportion of hospitalisations complicated by GIH increased from 2.12% in 2007 to 7.46% in 2011 (p < 0.01). Gastrointestinal haemorrhage was more common in men (56.7%) and in Caucasians (57.4%). Common comorbidities in this population were renal failure (71%), anaemia (55%), and hypertension (26%). All-cause inpatient mortality showed a numerical but nonsignificant increase from 56.7% to 61.9% (p = 0.49). The average cost of care per hospitalisation with GIH associated with ECMO use increased from $132,420 in 2007 to $215,673 in 2011 (p < 0.01).

Conclusions

Gastrointestinal haemorrhage during ECMO hospitalisations occurred in small but significantly increasing proportions. The inpatient mortality rate and costs associated with GIH were substantial and increased significantly during the study period.
Correlation analysis of adjuvant chemotherapy duration and postoperative death in Chinese patients with colorectal cancer: a retrospective cohort study
Authors: Chen Weiwei , Wang Gang , Dong Hongmin , Wang Wenling
Published: March 2021

Introduction

It is not known whether adjuvant chemotherapy duration is non-linearly associated with postoperative mortality risk. This study was designed to examine this relationship in Chinese patients with colorectal cancer.

Material and methods

This cohort study was conducted in 1171 participants with stage III and high-risk stage II colorectal cancer, who were treated in China between July 1, 2011, and September 1, 2018. The target independent variable was adjuvant chemotherapy duration, and the dependent variable was postoperative death.

Results

After adjusting for confounding factors, an increase in adjuvant chemotherapy duration was negatively correlated with the risk of postoperative death (hazard ratio (HR) = 0.95, 95% confidence interval (CI): 0.900.99). However, a non-linear relationship between therapy duration and postoperative death was observed in the group with bolus and infused fluorouracil with oxaliplatin (FOLFOX). In this group, the incidence of death decreased only when chemotherapy duration was more than 14 weeks (HR = 0.78, 95% CI: 0.630.97). A stronger association between adjuvant chemotherapy duration and postoperative death was detected in the capecitabine and oxaliplatin (CAPOX) group (HR = 0.71, 95% CI: 0.55–0.94) compared with the FOLFOX group (HR = 0.96, 95% CI: 0.92–1.01).

Conclusions

The duration of adjuvant chemotherapy with the FOLFOX regimen is associated with a non-linear reduction in postoperative deaths, which is only apparent after at least 14 weeks of treatment. However, patients with colorectal cancer may receive CAPOX adjuvant treatment for a longer duration.
Unprovoked pulmonary embolism in older adults: incidence and prognosis
Authors: Aharoni Mor , Horesh Nir , Rogowski Ori , Kremer Anjelika , Mayan Haim , Justo Dan
Published: March 2021

Introduction

Unprovoked pulmonary embolism (UPE) is not rare and it is associated with an unfavorable prognosis in adults. However, the incidence and the prognosis of UPE in older adults have never been studied.

Material and methods

This was a historical prospective study. We reviewed all the medical charts of all older adults (aged 70 years or more) with UPE, provoked pulmonary embolism (PPE), and malignancy-associated PE (MAPE), admitted to a tertiary medical center between 2010 and 2012. The all-cause 3-year mortality rates and cumulative survival following admission were compared between the groups.

Results

The final cohort included 249 patients with PE: 161 (64.7%) were women; the mean age was 79.8 ±5.7 years. Overall, 36 (14.5%) patients had UPE, 81 (32.5%) patients had MAPE, and 132 (53.0%) patients had PPE. Overall, 39 (15.7%) patients died within 30 days, 76 (30.5%) patients died within 6 months, 101 (40.6%) patients died within 1 year, and 136 (54.6%) patients died within 3 years of admission. Relative to PPE and MAPE patients, the cumulative survival was significantly higher in UPE patients at each time point within 1 year of admission (p < 0.05 and p < 0.001, respectively). However, 3 years after admission, the cumulative survival was comparable between PPE patients and UPE patients, and was significantly lower in MAPE patients (p < 0.001).

Conclusions

UPE is not rare in older adults with PE, and it is associated with a favorable prognosis within 1 year of admission in this population.
Reframing the Arab Spring : On Data Mining and the Field of Arab Internet Studies
Authors: Sakr Laila Shereen
Published: March 2021

This chapter presents a basic genealogy of the existing literature on the
2010–2012 era of the Arab Spring within Middle East studies and media
studies more broadly. The aim is to map the plurality of patterns, stories,
ideas, and analyses networked across media forms. This chapter is designed
to refute the possibility of a monolithic narrative about contemporary
Egypt. It also situates the study within the growing scholarship on social
media and political change and introduces key concepts in design research
methodology.
A formação do complexo florestal celulósico brasileiro
Authors: Lima de Aquino Silvia
Published: March 2021

O artigo analisa o surgimento da indústria de papel e celulose e a consolidação do complexo celulósico florestal no Brasil. Com este intuito examina o modo pelo qual o setor se transformou de um conjunto de pequenas fábricas em um complexo agroindustrial, com uma cadeia produtiva articulada. Entende-se que a consolidação do referido complexo teve como fator central a articulação entre interesses agrários e industriais, mediados pelo Estado, que esteve e se mantém vinculado ao mesmo, ora como orquestrador de interesses; ora como investidor; e por vezes como promotor de políticas públicas. Para fundamentar a reflexão realizou-se pesquisa bibliográfica e análise de documentos relacionados ao aparato legal destinado ao setor no Brasil. Conclui-se que o uso do eucalipto e da celulose de fibra curta na fabricação de papéis, nos anos 1950, provocou uma guinada na indústria brasileira do setor, até então, muito rudimentar. Esta passou a fabricar sua matéria-prima, antes, majoritariamente, importada. Devido às condições favoráveis a eucalipto cultura e em virtude do importante papel do Estado na concessão de incentivos fiscais, por meio de legislações, planos de desenvolvimento e políticas públicas destinados não só a introdução dos plantios e a fabricação de papéis, mas, também a produção de celulose, o Brasil se tornou um dos maiores fabricantes de celulose de fibra curta do mundo.
Avaliação do Programa Nacional de Produção e Uso de Biodiesel no Contexto do Desenvolvimento Regional e Inclusão Social
Authors: Gilberto Cavalcante Filho Pedro , Buainain Antônio Márcio , Pereira da Cunha Marcelo
Published: March 2021

Este trabalho tem o objetivo de avaliar a experiência do Programa Nacional de Produção e Uso do Biodiesel (PNPB) no contexto do desenvolvimento regional nos últimos dez anos. A metodologia utilizada neste trabalho tem natureza descritiva, exploratória e explicativa mediante o levantamento bibliográfico, documental e análise do banco de dados da Agência Nacional do Petróleo, Gás Natural e Biocombustíveis (ANP) e do Selo Combustível Social (SCS). Os resultados indicam que as usinas se estabeleceram nas regiões tradicionalmente produtoras de soja, como Sul e Centro-Oeste, mostrando uma coordenação das forças de mercado e não da ação norteadora do Estado brasileiro e distorceu os objetivos de promoção do desenvolvimento regional no Norte e Nordeste. Essa condição se refletiu na concentração da inclusão social dos agricultores familiares sulistas, especificamente o Rio Grande do Sul, que apresenta um modelo de desenvolvimento agrícola e configurações sociais distintas das demais regiões, possibilitando maior nível de inclusão.
MODELAGEM DAS VARIÁVEIS DO ENSAIO DE DESGASTE DO REVESTIMENTO DE CARBONETO DE CROMO
Authors: Alves Manoel Henrique , Alves Annelise Kopp
Published: March 2021

Este trabalho tem como objetivo avaliar numericamente a taxa média de desgaste do revestimento de carboneto de cromo na matriz NiCr aspergido via HVOF em aço, através da regressão multivariada. A modelagem é realizada através de variáveis importantes de entrada no mecanismo de desgaste, a carga estática, velocidade e distância de deslizamento. Para isso foi feito uma pesquisa em artigos publicados em revistas internacionais para formar um banco de dados sobre esse revestimento, com dados experimentais já realizados. Com isso é modelado uma previsão da taxa média de desgaste do revestimento de acordo com tais variáveis gerando uma equação previsora.  A modelagem se mostrou forte numericamente para prever o quanto o revestimento vai se desgastar. Pode-se verificar que a carga estática é uma variável determinante na previsão da taxa média de desgaste, sendo uma grandeza diretamente proporcional.
SABERES DOCENTES: AS PERSPECTIVAS PROFISSIONAIS DE PROFESSORES DE ENSINO TÉCNICO
Authors: Oliveira André Luís Pinto de , Romano Alessandro Segala , Prados Rosália Maria Netto
Published: March 2021

Este artigo discute as perspectivas profissionais de professores que atuam em uma instituição pública de educação técnica e tecnológica do Estado de São Paulo. Baseia-se em estudos sobre saberes docentes, educação profissional e formação de professores. Seus objetivos são descrever os saberes que constituem o professor e analisar suas perspectivas profissionais. No desenvolvimento desta discussão, propõe-se, de acordo com uma metodologia de abordagem qualitativa a partir dos saberes docentes estudados, uma análise das perspectivas dos professores em relação à sua profissão. Nesta análise, foi aplicado o programa IRAMUTEQ, software de análise de conteúdo, para identificar e visualizar os saberes docentes e suas perspectivas profissionais. Os estudos mostraram que a profissão docente em educação profissional requer vivência em sala de aula, bem como nas demais atividades profissionais, além de atualização constante de conhecimentos.
A PERCEPÇÃO DE ALUNOS DO 4.º ANO DO ENSINO FUNDAMENTAL DO MUNICÍPIO DO RIO DE JANEIRO SOBRE INSETOS COMO BASE PARA A FORMULAÇÃO DE UM CURRÍCULO DE ENTOMOLOGIA
Authors: D’Escoffier Luiz Ney
Published: March 2021

Popularmente, os insetos são relacionados a doenças, ditos nojentos, nocivos ou perigosos e animais que não pertencem a esta classe são confundidos com eles. Para a definição de metas visando a eliminação destes preconceitos, é preciso inteirar-se dos conhecimentos prévios sobre insetos. Nosso objetivo foi levantar que conhecimentos, conceitos e influências alunos do 4.º ano do ensino fundamental de escolas públicas da cidade do Rio de Janeiro possuem sobre insetos. Através de um questionário, concluímos que conhecem pouco, não conseguem distingui-los de outras classes de animais, trazem conceitos negativos e agressivos reproduzindo concepções familiares. Propomos que ao elaborar um currículo de entomologia as percepções dos alunos sejam consideradas, já que são influenciadas pelas concepções culturais.
PROPOSTA DE PROGRAMA DE PREVENÇÃO DE RISCOS AMBIENTAIS PARA UMA EMPRESA DE PEQUENO PORTE
Authors: Farias Júnior Artur Alves
Published: March 2021

Povoadas de detalhes e exceções, as leis trabalhistas brasileiras podem até não ser consideradas das mais simples para um entendimento rápido, mas é certo que, apesar disso, alguns termos já fazem parte do dia a dia de empregadores e empregados nas empresas e entre esses está o Programa de Prevenção de Riscos Ambientais (PPRA). O presente artigo tem por objetivo demonstrar de forma prática a aplicação de um PPRA numa empresa de pequeno porte, prestadora de serviços na construção civil, situada no município de Aracaju-Sergipe. Este trabalho, baseado nos parâmetros mínimos e diretrizes gerais estabelecidos pela Norma Regulamentadora NR-9, é resultado de uma consultoria de segurança do trabalho e meio ambiente numa empresa que, em 2018, passava a atuar em prédio próprio e buscava estabelecer medidas para redução, controle ou eliminação desses riscos em prol da preservação da integridade física dos seus colaboradores, bem como adequação à legislação e normativas.
OBJETO DE APRENDIZAGEM — ENSINO DE SISTEMAS DE EQUAÇÕES LINEARES APLICADOS EM CIRCUITOS
Authors: Ramos Fábio Mendes
Published: March 2021

O presente estudo, apesar de não se tratar de assunto novo no âmbito educacional, vem a colaborar com o tema é Prática pedagógica, no Ensino de Sistemas de Equações Lineares, teve como pressuposto a elaboração de um Objeto de Aprendizagem para o Ensino Médio e Educação Profissional, o qual foi desenvolvido como método dinâmico e interativo para o ensino-aprendizagem desse conteúdo. A metodologia empregada buscou instrumentar da tecnologia informática na elaboração de um Objeto de Aprendizagem, desenvolvido e implementado em sua pluralidade nos softwares GeoGebra e Notpad++ por meio de uma sequência didática. As atividades dessa sequência foram elaboradas e aplicadas a estudantes do Ensino Médio e Educação Profissional. Espera-se que o Objeto de Aprendizagem contribua para a reflexão e melhor compreensão dos alunos, possibilitando uma relação entre os conteúdos de Matemática e das áreas técnicas na resolução de problemas de Circuito de malhas. O Objeto de Aprendizagem foi disponibilizado no site (http://www.fabioramos.mat.br/), visando a (re)utilização por professores, pesquisadores e alunos.
Assessment of avalanche hazards using remote sensing in the lower Yellow River, China
Authors: Gao Lu , Xu Xiangzhou , Zhao Ying , Tarolli Paolo
Published: March 2021

Abstract: Riverbank collapses frequently occur in the lower reaches of the Yellow River, China, which cause environmental changes around the riverbanks and result in a great loss of farmland. An analysis was carried out to understand the riverbanks of the Jiyang Reach via Google Earth. The results show that the three representative segments in the Jiyang Reach, the maximum annual-lateral displacement and average retreat area were 26.0 m/a and 1083.8 m2 during the period 3/31/2016–5/10/2018, respectively. Several factors such as the soil properties, upstream river-control works, bridge piers, and channel bends may change the river flow direction and the scour intensity, thereby increasing the probability of downstream riverbank collapse, which are all causes of riverbanks collapse in the lower Yellow River. Field investigation and research data show that the lower reaches of the Yellow have serious bank-collapse disasters and their riverbanks are still in an unstable state.

keywords: Riverbank collapse; Yellow River; Channel evolution; Riverbank protection
Formation of solar coronal loops through magnetic reconnection in an emerging active region
Authors: Hou Zhenyong , Tian Hui , Chen Hechao , Zhu Xiaoshuai , He Jiansen , Bai Xianyong , Huang Zhenghua , Xia Lidong
Published: March 2021

Coronal loops are building blocks of solar active regions (ARs). However, their formation is not well understood. Here we present direct observational evidence for the formation of coronal loops through magnetic reconnection as new magnetic fluxes emerge to the solar atmosphere. Observations in the EUV passbands of SDO/AIA clearly show the newly formed loops following magnetic reconnection within a vertical current sheet. Formation of the loops is also seen in the Hα images taken by NVST. The SDO/HMI observations show that a positive-polarity flux concentration moves toward a negative-polarity one with a speed of ~0.5 km s-1 before the apparent formation of coronal loops. During the formation of coronal loops, we found signatures of flux cancellation and subsequent enhancement of the transverse field between the two polarities. We have reconstructed the three-dimensional magnetic field structure through a magnetohydrostatic model, which shows field lines consistent with the loops in AIA images. Numerous bright blobs with a width of ~1.5 Mm appear intermittently in the current sheet and move upward with apparent velocities of ~80 km s-1. We have also identified plasma blobs moving to the footpoints of the newly formed large loops, with apparent velocities ranging from 30 to 50 km s-1. A differential emission measure analysis shows that the temperature, emission measure and density of the bright blobs are 2.5-3.5 MK, 1.1-2.3×1028 cm-5 and 8.9-12.9×109 cm-3, respectively. Power spectral analysis of these blobs indicates that the magnetic reconnection is inconsistent with the turbulent reconnection scenario.
Characteristics of Rainfall- Groundwater Level Response in Taipei City, Taiwan
Authors: Chen Shih-Kai , Lin Yuan-Jie , Lee Yuan-Yu
Published: March 2021

The Taipei Basin, Taiwan has been densely populated and highly economically developed in recent decades. Global climate change has led to frequently flooding and drought events in recent years, formulating suitable measures to mitigate climatic disaster has become a crucial issue in this city. The sponge city concept is one of the most important options for disaster mitigation in highly urbanization areas. However, the city is also potentially threatened by soil liquefaction due to its sedimentary geology and increasing groundwater level. High groundwater level might be a key limiting factor in the promotion of sponge city. The aim of this study was to understand the relationship between rainfall and groundwater level and the impacts of cumulative rainfall, depth to groundwater table, and impervious pavement ratio on the rainfall/groundwater level response in study area. The cross-correlation function (CCF) was applied to analyze the correlation between rainfall and groundwater level data obtained from 20 observed wells and nearby rainfall gages during dry and wet seasons from 2012 to 2017. The significance groundwater recharge response can be found in 61% and 37% of the observation wells during the wet and dry seasons, respectively. Compared with the factors such as cumulative rainfall, and depth to groundwater table, the ratio of surface impervious pavement is the primary affecting factor behind the correlation between rainfall and groundwater level response. The analysis results also show the areas with shallow groundwater level, high imperious pavement ratio, and the groundwater level with no significant response to rainfall, are almost overlapped with the middle and high level liquefaction potential areas in this city. Measures such as the application of the sponge city concept to increase infiltration should be carefully reevaluated in this city. The research results can provide a reference for the future development of urban water resources management and disaster mitigation strategies under the challenge of globe climate change.
Effect of decreasing sediment supply and sea level rise on the long-term morphodynamics of a large estuary
Authors: Yuan Bing , Sun Jian , Lin Binliang , Zhang Fanyi
Published: March 2021

Globally the riverine sediment supply to estuaries is decreasing and the mean sea level is rising, while the effects of these changes on the long-term estuarine morphodynamics have not been fully investigated. An idealized numerical model was used to explore the long-term morphodynamics of a large estuary subject to these changes. In the model, a funnel-shaped channel with fixed banks, constant riverine water and sediment fluxes, a single grain size and a semi-diurnal tide were used. A range of values of changes in the sediment supply (50-90% reduction) and sea level (1-5~mm/yr increase) were considered. Starting from an equilibrium state for an initial sediment supply, the estuary shifts to a new equilibrium for the considered changes on a timescale of millennia. Half of the bed level change occurs within several hundreds of years. A larger decrease in the sediment supply leads to a stronger bed erosion, while the corresponding adjustment time has minor changes in its range for the considered settings. When combined with sea level rise, the erosion is weakened and the adjustment time is shortened. The equilibrium state under sea level rise is characterized by a bed level keeping pace with the sea level and a significant amount of sediment being trapped in the estuary. Additional numerical experiments that use more realistic geometry and forcing of the Yangtze Estuary show that overall erosion of the estuary is expected for centuries.
Preliminary results for stratigraphy and chronology of blue ice in Larsen Glacier, East Antarctica
Authors: Lee Giyoon , Ahn Jinho , Ju Hyeontae , Ritterbusch Florian , Oyabu Ikumi , Kim Songyi , Kawamura Kenji , Lu Zheng-Tian , Han Sangyoung , Ghosh Sambit , Han Yeongcheol , Hong Sangbum , Han Changhee , Hur Soon Do , Jiang Wei , Yang Guomin
Published: March 2021

Among the paleoclimate archives, we may take advantage of ice cores to directly measure greenhouse compositions of ancient air. Nevertheless, ice cores from deep drilling projects recover limited amount of ice for a given time period and hence limiting the studies that need an extensive amount of ice such as trace gas isotopes. In contrast, blue ice areas (BIAs) may provide a large amount of ancient ice outcropped at the surface. However, ice flow makes the blue ice stratigraphy complicated in many areas, and accordingly makes it difficult to reconstruct a continuous stratigraphy. Recently, the oldest ice was discovered at Allan Hills BIA (about 2.7 Ma). However, the stratigraphy is not continuous for the older part. Here we show preliminary results from Larsen Glacier, East Antarctica. The Ground Penetrating Radar (GPR) results show parallel ice layers near the surface with dips of 1-5° and indicate that the ice thickness ranges of 200–400 m. δDice of a vertical core sample matches well with that in the horizontally spaced surface ice samples. Greenhouse gas concentrations are significantly altered at shallow depths of < ~4.5 m. The δ18Oatm, CH4 concentration and stable isotopes of ice (δ18Oice, δDice) indicate that the Larsen BIA cover the Last Glacial Termination at the studied sites. 81Kr ages, corrected by 85Kr for the modern air contamination, are less than 54 ka, supporting the ages constrained by the other chemistry data.
Natural disasters and architecture: the 2016 Venice Architecture Biennale "Reporting from the front"
Authors: Bostenaru Dan Maria
Published: March 2021

Napoleon founded, after drainage and demolition, the Giardini in Venice, which in the 19th century (1985 first edition) started to be the ground for the Venice Biennale. Pavillions were built for different countries, after the model of World Exhibitions. The Venice Biennale was at the begin an art exhibition. Since 1975 the Art Biennale takes place alternatively with the architecture Biennale, each of them every two years. In 2016, the 15th Architecture Biennale was curated by Alejandro Aravena and had the title "Reporting from the front". The Biennale features central pavillions at the Giardini and at the Arsenale (a younger extension), and in the free spaces, and also 61 national pavillions. Google Arts and Culture archived the Biennale 2016 as a museum and it can be consulted also afterwards by anyone. Among others, it called for contributions presenting how architecture is dealing with natural disasters. The overall call and interdependence between natural disasters mitigation and sustainability will be presented. The response to the call was mainly approaching man-made disasters, but also installations on climate change dedicated museums or on disaster resistant infrastructure by Marte architects. The curator himself received 2016 the Pritzker prize, the most prestigious one for architecture, among others for acclaimed work in reconstructing 2010 after an earthquake and tsunami in Chile, using participatory means. Participatory means have an important footprint at the Biennale. 2006 already the USA presented at the Biennale in their Pavillion dealing with the aftermath of Kathrina.

The contribution at the EGU will compare this approach with the latest developments in participatory approaches to disaster management, also approached in other research works of the author (ex. NHESS publication from 2004, present in the encyclopedia entry), and of dedicated associations (ex. i-REC). It is an endeavour of the contribution of the author to show how architecture and urban planning can contribute to disaster mitigation, also in this session. The author visited the 2016 Venice Architecture Biennale and will report a first hand experience with artistic presentation of the approach to disasters.
Parcels 2.2 - An increasingly versatile, open-source Lagrangian ocean simulation tool
Authors: Kehl Christian , Reijnders Daan , Fischer Reint , Brouwer Roel , Schram Raoul , van Sebille Erik
Published: March 2021

Lagrangian simulations contribute to the study and comprehension of particulate-matter transport, its dissolution and dispersion in the oceans. Parcels is an open-source, Python-based module for Lagrangian ocean simulations. It is a known tool in the oceanographic community that has been applied to a variety of case studies, such as the tracing of microplastics, the backtracking of ocean floor plankton, and the migration of fish. In this module, particles are advected over time according to a selected flow field, where those particles can represent particulate-matter, biota or other objects with physical, hydrodynamic or biogeochemical properties. In this contribution, we present the substantial extensions of Parcels with respect to usability, physics modelling aspects of particle advection, and computational aspects of versatile, scalable and efficient simulations.

Specifically, a suite of simple, concise notebook tutorials are tailored to novice user, covering step-by-step simulation setup instructions, whereas self-contained special-issue tutorials address advanced- and proficient user requirements. The considerable expansion of supported OGCM flow field input formats (e.g. MITgcm, POP and MOM5, among others) is a major interest in Parcels v2.2 for our steadily-growing user base.

The new version further integrates previously-published physics methods into practical lagrangian particle simulations. As such, we implement an analytical advection scheme in addition to existing Runge-Kutta advection schemes. Furthermore, two-dimensional advection-diffusion is upgraded with the Milstein stochastic integration scheme and improved documentation. Those capabilities enable a more consistent modelling of diffusion- and uncertainty-dominated fluid transport processes.

The case studies performed with previous versions indicate increased computational demands. Simulations are run over long decadal time scales as well as over day-periods with sub-second temporal increments, involving multiple basins and global scenarios, while also modelling increasingly complex particle processes. Overall, our developments respond to the big-data requirements of modern oceanographic studies, which include the aspects of (i) high record volume (i.e. large number of particles), (ii) high dimensionality in multi-variate records, (iii) high spatial resolution, (iv) high temporal resolution, (v) high scenario (i.e. case study) variability and (vi) the prevention of numerical error accumulation over long simulation time scales.

The novel features of Parcels v2.2 are illustrated on distinct case studies within our contribution, in order to connect the technical features to their impact on particulate-matter ocean transport studies.
Respective and combined impacts of regional SST anomalies on tropical cyclogenesis in different sectors of the western North Pacific
Authors: Wu Renguang
Published: March 2021

Tropical cyclone activity over the western North Pacific (WNP) is subjected to impacts of sea surface temperature (SST) anomalies in the three tropical oceans. In this talk, the interannual variations in the tropical cyclone (TC) over the WNP and the influences of regional SST anomalies are documented by separating the WNP into four quadrants considering SST-induced non-uniform environmental changes. It will be shown that the TC variations in the northwest and southeast quadrants are related to both equatorial central-eastern Pacific (EPO) and tropical Indian Ocean (TIO) SST anomalies. The TC variation in the northeast quadrant is mainly related to tropical North Atlantic Ocean (TNA) SST anomalies. The main environmental variables differ for the TC variations in the four quadrants. Low-level (850-hPa) vorticity is important for the TC variations in the northwest, southwest and southeast quadrants. Mid-level (700-hPa) humidity contributes to the TC variations in the northwest, northeast and southeast quadrants. The vertical shear has a supplementary contribution to the TC variation in the southeast quadrant. The potential intensity negatively affects the TC variations in the southwest and southeast quadrants. The remote SST anomalies modulate different environmental variables over the WNP. The TIO SST influence is manifested in the low-level vorticity and vertical motion. The TNA SST impact occurs through the low-level vorticity change. The EPO SST effect occurs via changing the low-level vorticity and vertical motion as well as the mid-level moisture and vertical shear. The environmental variables experience more prominent changes when SST anomalies coexist in two remote regions. Numerical experiments confirm the EPO and TIO SST anomaly impacts on the environmental conditions affecting the WNP TC variations.
Characteristic of daytime F-region backscatter plume structures over low latitude of China
Authors: Xie Haiyong
Published: March 2021

Ionospheric F‐region irregularity backscatter plumes are commonly regarded as a nighttime phenomenon at equatorial and low latitudes. At daytime, there are very few reported cases of F‐region backscatter echoes. It is still not clear what caused the daytime echoes. In order to understand the occurrence of daytime F‐region echoes, we carried out an experiment with Sanya VHF radar (18.4°N, 109.6°E, dip lat. 12.8°N) during November 2016 to August 2020. Some basic characteristics were released: (1) The daytime F‐region echoing structures have an unexpected high occurrence in June solstice of solar minimum. (2) The echoing structures could appear at any time during 0700–1800 LT, with a maximum occurrence around 0900 LT. (3) The echoing structures appeared mostly above 350 km altitude, extending up to 650 km or more (F region topside) with apparent westward drifts at times. Radar interferometry and ICON satellite in situ results show that the daytime F‐region echoes were from plume structures consisting of field‐aligned irregularities. It is suggested that the plume structures could be remnants of equatorial plasma bubble (EPB) irregularities generated on the previous night around 100–125°E. They rise to high altitudes and drift zonally together with background plasma, causing the daytime F‐region backscattering structure over Sanya. With simultaneous observations of several VHF radars at different locations, satellite in-situ measurements and/or EPB model, the dynamics of daytime F-region backscatter plume structures could be better understood in the future.
Geochemical modeling and multivariate statistical approach for assessing the groundwater quality, and mechanism of arsenic mobilization in Bahraich region, Indo-Gangetic plains, India
Authors: Khan Mohd Usman , Rai Nachiketa , Sharma Mukesh Kumar
Published: March 2021

As contamination in groundwater has been reported from various regions of the Indian subcontinent but no data related to heavy metal contamination of groundwater has been reported for the Bahraich area in the Indo-Gangetic plains. We report the first dataset on arsenic contamination and groundwater hydrogeochemistry, in Bahraich. This includes concentrations of heavy metal such as As, Mn, and Fe, along with major cations (Na+, K+, Ca2+and Mg2+) and anions (F-, Cl-, NO3-, SO42- and PO43-), and dissolved organic carbon (DOC), along with various physico-chemical parameters such as EC, pH, and Eh from samples collected during two extensive field campaigns conducted during pre-monsoon, and post-monsoon seasons respectively. The combined use of geochemical modeling and multivariate statistical approaches such as principal component analysis (PCA) and correlation analysis (CA) suggest several processes affecting the geochemistry of groundwater including the lithological characteristics of aquifers and anthropogenic activities.

The groundwater of the study area predominantly belongs to the Ca-Mg-HCO3 type hydrochemical facies. HCO3−/Na+ and Ca2+/Na+ signatures of groundwater indicate the influence of silicate weathering and carbonate dissolution processes with the insignificant role of evaporate dissolution mechanism. As concentration was found to range from 0.6 μg/L to ~100 μg/L with almost 40% of the collected samples exceeding the WHO defined limit of 10 μg/L for drinking water. 70 % of the groundwater samples were found to have very high Fe concentrations exceeding the WHO guideline of 0.3 mg/l in drinking water. Mn concentrations in the groundwater samples were relatively low with only ~10 % of the samples exceeding the WHO defined limit for Mn (400 μg/L). The majority of the groundwater samples were found to be anoxic in nature showing low NO3− & SO42- concentrations, high Fe & Mn and DOC concentrations, and negative Eh values.

Results from this study show that the reductive dissolution mechanism of iron oxyhydroxide is the dominant mechanism responsible for arsenic release in groundwater of the region, ruling out any role of sulfide oxidation and alkali desorption.

 

 
Understanding change in hydrometeorological extremes with statistical models - the importance of model parametrization
Authors: Prosdocimi Ilaria , Kjeldsen Thomas
Published: March 2021

The potential for changes in hydrometeorological extremes is routinely investigated by fitting change-permitting extreme value models to long-term observations, allowing one or more distribution parameters to change as a function of time or some physically-motivated covariate. In most practical extreme value analyses, the main quantity of interest though is the upper quantiles of the distribution, rather than the parameters' values. This study focuses on the changes in quantile estimates under different change-permitting models. First, metrics which measure the impact of changes in parameters on changes in quantiles are introduced. The mathematical structure of these change metrics is investigated for several models based on the Generalised Extreme Value (GEV) distribution. It is shown that for the most commonly used models, the predicted changes in the quantiles are a non-intuitive function of the distribution parameters, leading to results which are difficult to interpret. Next, it is posited that commonly used change-permitting GEV models do not preserve a constant coefficient of variation, a property that is typically assumed to hold and that is related to the scaling properties of extremes. To address these shortcomings a new (parsimonious) model is proposed: the model assumes a constant coefficient of variation, allowing the location and scale parameters to change simultaneously. The proposed model results in more interpretable changes in the quantile function. The consequences of the different modelling choices on quantile estimates are exemplified using a dataset of extreme peak river flow measurements.
Pre-seismic geomagnetic anomalous signature related to the Mw7.0 earthquake generated in the northern coastal zone of Samos island – Greece, on October 30, 2020
Authors: Stanica Dumitru , Stanica Dragos Armand
Published: March 2021

A strong earthquake of magnitude Mw7.0 struck the northern coastal zone of Samos Island, Aegean See, Greece, on October 30, 2020, at 11:51 UTC. This earthquake was felt at a wide area including Athens (at 270km) and city of Heraklion, Crete (at 320km), causing over 120 deaths and a lot of damages on houses, buildings and infrastructures mainly in Samos Island and Izmir (Turkey). With the aim to identify an anomalous geomagnetic signature before the onset of this earthquake, we have retrospectively analyzed the data collected, on the interval September 16 - October 31, 2020, at the two geomagnetic observatories, Pedeli (PEG)-Greece and Panagjurishte (PAG)-Bulgaria, by using the polarization parameter (BPOL) and the strain effect–related to geomagnetic signal identification. Thus, for the both observation sites (PEG and PAG), the daily mean distribution of the BPOL and its standard deviation (SD) are carried out using a FFT band-pass filtering in the ULF range (0.001-0.0083Hz). Further on, a statistical analysis based on a standardized random variable equation was applied for the following two particular cases: a) to assess on the both time series BPOL*(PEG) and BPOL*(PAG) the anomalous signature related to Mw7.0 earthquake; b) to differentiate transient local anomalies associated with Mw7.0 earthquake from the internal and external parts of the geomagnetic field, taking the PAG Observatory as reference. Finally, on the BPOL*(PEG-PAG) time series, carried out on the interval 1-31 October, 2020, a very clear anomaly of maximum, greater than 1.2SD, was detected on October 27, with 3days before the onset of Mw7.0 earthquake.
Intensified paraglacial slope failures due to accelerating downwasting of a temperate glacier in Mt. Gongga, Southeastern Tibet Plateau
Authors: Zhong Yan , Liu Qiao , Nie Yong , Westoby Matthew , Zhang Bo , Cai Jialun , Liao Haijun , Liu Guoxiang
Published: March 2021

Topographic development via paraglacial slope failure (PSF) represents a complex interplay between geological structure, climate, and glacial denudation. Where debris generated by PSFs is deposited on the surface of a glacier, this debris can increase the extent or thickness of a supraglacial debris-cover, in turn modifying glacier ablation and affecting meltwater generation. To date, little attention has been paid to intensity and frequency of PSFs and their significance as a geomorphic agent and hazard in glacierised, monsoon temperate regions of Southeast Tibet. We mapped PSFs along the 5 km-long, west-east trending ice tongue of Hailuogou Glacier (HLG), Mt. Gongga, using repeat satellite- and UAV-derived imagery between 1990 and 2020. Three types of PSF were identified: (A) rock fall, (B) slide and collapse of sediment-mantled slopes, and (C) gulley headwards erosion. We analyzed the formation, evolution and current state of these PSFs and discuss these aspects with relation to glacier dynamics and paraglacial geomorphological history. South-facing slopes (true left of HLG) showed more destabilization and higher PSF activity than north-facing slopes. We observed annual average rates of downslope sliding for type B PSFs of 1.6-2.6 cm d-1, whereas the average upward denudation rate for type C PSFs was 0.7-3.39 cm d-1. We show that type A PSFs are non-ice-contact rock collapses that occur as a long-term paraglacial response following glacier downwasting and the exposure of steep rocky cliffs and which could also be influenced by precipitation, freeze-thaw cycling, earthquakes or other factors. In contrast, type B and C PSFs are a more immediate response to recent glacier downwasting. We further argue that the accelerating downwasting of glacier are used as a preparatory or triggering factor, which could directly or indirectly cause the PSFs.