Benthic foraminifera as tracers of brine production in the Storfjorden "sea ice factory"

The rapid response of benthic foraminifera to environmental factors (e.g. organic matter quality and quantity, salinity, pH) and their high fossilisation potential make them promising bio-indicators for the intensity and recurrence of brine formation in Arctic seas. Such an approach, however, requires a thorough knowledge of their modern ecology in such extreme settings. To this aim, seven stations along a north-south transect across the Storfjorden (Svalbard archipelago) have been sampled using an interface multicorer. This fjord is an area of intense sea ice formation characterised by the production of brine-enriched shelf waters (BSW) as a result of a recurrent latent-heat polynya. Living (rose bengal-stained) foraminiferal assemblages were analysed together with geochemical and sedimentological parameters in the top 5 cm of the sediment. Three major biozones were distinguished. (i) The inner fjord zone, dominated by typical glacier proximal calcareous species, which opportunistically respond to fresh organic matter inputs. (ii) The deep basins and sill zone, characterised by glacier distal agglutinated fauna; these are either dominant because of the mostly refractory nature of organic matter and/or the brine persistence that hampers the growth of calcareous species and/or causes their dissolution. (iii) The outer fjord zone, characterised by typical North Atlantic species due to the intrusion of the North Atlantic water in the Storfjordrenna. The stressful conditions present in the deep basins and sill (i.e. acidic waters and low food quality) result in a high agglutinated = calcareous ratio (A=C). This supports the potential use of the A=C ratio as a proxy for brine persistence and overflow in Storfjorden

Benthic foraminifera as tracers of brine production in the Storfjorden "sea ice factory"

Abstract. The rapid response of benthic foraminifera to environmental factors (e.g. organic matter quality and quantity, salinity, pH) and their high fossilisation potential make them promising bio-indicators for the intensity and recurrence of brine formation in Arctic seas. Such an approach, however, requires a thorough knowledge of their modern ecology in such extreme settings. To this aim, seven stations along a north–south transect across the Storfjorden (Svalbard archipelago) have been sampled using an interface multicorer. This fjord is an area of intense sea ice formation characterised by the production of brine-enriched shelf waters (BSW) as a result of a recurrent latent-heat polynya. Living (rose bengal-stained) foraminiferal assemblages were analysed together with geochemical and sedimentological parameters in the top 5 cm of the sediment. Three major biozones were distinguished. (i) The "inner fjord" zone, dominated by typical glacier proximal calcareous species, which opportunistically respond to fresh organic matter inputs. (ii) The "deep basins and sill" zone, characterised by glacier distal agglutinated fauna; these are either dominant because of the mostly refractory nature of organic matter and/or the brine persistence that hampers the growth of calcareous species and/or causes their dissolution. (iii) The "outer fjord" zone, characterised by typical North Atlantic species due to the intrusion of the North Atlantic water in the Storfjordrenna. The stressful conditions present in the deep basins and sill (i.e. acidic waters and low food quality) result in a high agglutinated ∕ calcareous ratio (A∕C). This supports the potential use of the A∕C ratio as a proxy for brine persistence and overflow in Storfjorden

Un décor peint médiéval découvert et restauré au XIXe siècle dans l’église Notre-Dame-du-bourg à Rabastens (Tarn) : critique d’authenticité et sa restauration aujourd’hui

La quasi-totalité des élévations intérieures de l’église Notre-Dame-du-bourg à Rabastens (Tarn), environ 3 560 m2, est recouverte de peintures murales d’époques différentes restaurées principalement au XIXe, puis ponctuellement au XXe siècle.Oubliés et cachés sous des badigeons depuis 1594, des décors peints d’époque médiévale ont été découverts et restaurés de 1860 à 1863 par Joseph Engalière, artiste peintre. Aujourd’hui, la commune s’engage dans un programme de restauration générale du bâtiment et de ses peintures intérieures. Une étude de diagnostic de ces dernières s’est déroulée de 2017 à 2020. Dans la connaissance des décors et leur critique d’authenticité, la principale difficulté a été de mettre en évidence l’ampleur de la restauration - parties originales repeintes, parties reconstituées ou parties créées par Joseph Engalière. Plusieurs moyens ont été mis en œuvre : corrélations entre documents d’archives et observations sur place sous différents angles d’éclairage, sondages stratigraphiques, repérage des différents matériaux avec l’imagerie de fluorescence sous UV et leur identification grâce aux analyses élémentaires avec la spectroscopie d’émission atomique dans le plasma induit par le laser et la spectroscopie de fluorescence X. Cette approche combinée a permis de caractériser et de différencier précisément la peinture d’origine de l’intervention de Joseph Engalière.Aujourd’hui, comment envisageons-nous la conservation et la restauration de cet ensemble unique ? Une méthodologie à adapter à « grande échelle » en cours des différentes phases de travaux est proposée.Almost all the interior elevations of the church Notre-Dame-du-Bourg in Rabastens (Tarn), about 3 500 m2, are covered with mural paintings from different periods that were mainly restored in the 19th century, then punctually in the 20th century.Hidden under whitewash and forgotten since 1562, the 14th century painted decorations were discovered and restored by Joseph Engalière from 1860 to 1863. Today, the municipality is embarking on a program of general restoration to the building and its painted scenes. A diagnostic study of the latter took place from 2017 to 2020. With the knowledge of the decorations and their criticism of authenticity, the main difficulty was to highlight the extent of the restoration – originals repainted parts, reconstituted parts or parts created by Joseph Engalière. Several means have been implemented: correlations between archival documents and observations on site under different lighting angles, stratigraphic soundings, identification of different materials with UV fluorescence imaging and elemental analyses with atomic emission spectroscopy in plasma induced by laser as well as X-ray fluorescence spectroscopy. This combined approach made it possible to precisely characterize and differentiate the original painting from Joseph Engalière’s intervention.Today, how do we envisage the conservation and restoration of this unique ensemble, a methodology to be adapted on a "large scale" during renovations

Procjena akutne toksičnosti umjetnih aroma grožđa, šljive i naranče pomoću testova in vivo

The present study evaluates the acute toxicity of synthetic grape, plum and orange flavourings in root meristem cells of Allium cepa at the doses of 3.5, 7.0 and 14.0 mL/kg and exposure times of 24 and 48 h, and in bone marrow erythrocytes of mice treated orally for seven days with 0.5, 1.0, 2.0, 5.0 and 10.0 mL/kg of flavouring. The results of the plant test showed that grape, plum and orange flavourings, at both exposure times, inhibited cell division and promoted the formation of a significant number of micronuclei and mitotic spindle changes. These alterations were observed in at least one exposure time analysed, demonstrating a significant cytotoxic, genotoxic and mutagenic activity. In mouse bioassay, animals treated with 2.0, 5.0 and 10.0 mL/kg of flavouring died before the seventh day of treatment. The amounts of 0.5 and 1.0 mL/kg of the three additives were cytotoxic to erythrocytes, and treatment with the grape flavouring significantly induced the formation of micronucleated cells in the bone marrow of animals. Therefore, under the study conditions, the grape, plum and orange flavouring additives promoted significant toxicity to cells of the test systems used.U radu je ispitan akutni toksični učinak umjetnih aroma grožđa, šljive i naranče u dozama od 3,5; 7 i 14 mL/kg tijekom 24 i 48 sati na meristemske stanice korijena luka (Allium cepa) te u peroralnim dozama od 0,5; 1; 2; 5 i 10 mL/kg tijekom 7 dana na eritrocite iz koštane srži miševa. Rezultati pokazuju da je izlaganje meristemskih stanica korijena luka umjetnim aromama grožđa, šljive i naranče tijekom 24 i 48 sata inhibiralo diobu stanica te potaklo tvorbu većeg broja mikronukleusa i promjenu strukture diobenog vretena. Promjene su uočene već nakon 24 sata, što potvrđuje znatnu citotoksičnost, genotoksičnost i mutagenost umjetnih aroma. Miševi hranjeni s 2, 5 i 10 mL/kg umjetnih aroma uginuli su prije sedmog dana tretmana. Dodatak umjetnih aroma u dozama od 0,5 i 1 mL/kg smanjio je broj eritrocita u koštanoj srži miševa, a dodatak arome grožđa znatno je potaknuo tvorbu mikronukleusa. Stoga je zaključeno da arome grožđa, šljive i naranče pri navedenim uvjetima imaju izraženi toksični učinak na meristemske stanice korijena luka i eritrocite iz koštane srži miševa

Hepatitis E Virus Genotype 3 Diversity, France

We characterized 42 hepatitis E virus (HEV) genotype 3 strains from infected patients in France in 3 parts of the genome and sequenced the full-length HEV genotype 3f genome found in Europe. These strains are closely related to swine strains in Europe, which suggests zoonotic transmission of HEV in France

Avaliação da importância de modelos no ensino de biologia através da aplicação de um modelo demonstrativo da junção intercelular desmossomo

The present work involved the development of a representative model of the desmosome junction and its application to 172 students divided into beginners (1o semester of Nutrition and Biological Sciences) and veterans (2o of Nutrition and 4o of Biological Sciences) to test its effectiveness on the teaching-learning process. It was found that 78% of beginners and 82% of veterans were female; 98% had between 17 and 30 years-old; the majority (61% and 50%, beginners and veterans, respectively) assumed it was the first occasion they had contact with a model although at least 90% of them recognized the main represented structure (the desmosome); the majority of both groups said that the model allowed the recognition of junctional structures; 97% of beginners and 99% of the veterans declared that their knowledge about intercellular junctions and desmosome enhanced and 72% of beginners affirmed that their teachers possess models for practical classes compared to 33% in veterans. The attribution of scores exceeding 7 to the model revealed that its use in practical lessons is productive.O presente trabalho consistiu na elaboração de um modelo demonstrativo da junção desmossomo e na sua aplicação a 172 estudantes divididos em iniciantes (1o semestres de Nutrição e Ciências Biológicas) e veteranos (2o de Nutrição e 4o de Ciências Biológicas) para testar sua eficácia para o processo de ensino-aprendizagem. Verificou-se que 78% dos iniciantes e 82% dos veteranos eram do sexo feminino; 98% tinham entre 17 e 30 anos de idade; a maioria (61% e 50%, iniciantes e veteranos, respectivamente) afirmaram que era a primeira vez que tiveram contato com um modelo embora pelo menos 90% deles reconheceram a principal estrutura representada (o desmossomo); a maioria de ambos os grupos afirmaram que o modelo permitiu o reconhecimento das estruturas juncionais; 97% dos iniciantes e 99% dos veteranos afirmaram que seu conhecimento sobre junções intercelulares e desmossomo melhorou e 72% dos iniciantes disseram que seus professores dispõem de modelos para as aulas práticas contra apenas 33% dos veteranos. A atribuição de notas acima de 7 ao modelo revelou que sua utilização em aulas práticas é profícua.Palavras-chave: instrumentos, junções, aulas práticas

Potencial citotóxico, genotóxico e citoprotetor de extratos aquosos de Caesalpinia pyramidalis Tul., Caesalpinia ferrea Mart. e Caesalpinia pulcherrima Sw.

The legumenous Caesalpinia pyramidalys, Caesalpinia ferrea and Caesalpinia pulcherrima are widely used in folk medicine in many countries. Thus, this study aimed to cytogenetically evaluate, through the use of meristematic roots cells of Allium cepa, after the exposure times 24 and 48 hours, the cytotoxic potential of aqueous extracts, at concentrations 1 g/500 mL and 1 g/1000 mL, obtained from the inner bark of Caesalpinia pyramidalis, the pod of Caesalpinia ferrea and the leaves of Caesalpinia pulcherrima, and also verify the modulatory potential of these extracts on cellular alterations induced by Paracetamol. The treatment groups used were: negative control – distilled water; positive control – 0.008 mg/mL Paracetamol solution; plant aqueous extract control – water fraction from the plants at concentrations 1 g/500 mL and 1 g/1000 mL; and simultaneous treatment – water fraction from the plants at concentrations 1 g/500 mL and 1g/1000 mL associated with 0.008 mg/mL Paracetamol solution. The Chi-square statistical test was used at 5% probability for data analysis. The results showed that C. pyramidalis and C. ferrea had a significant antiproliferative effect on the cells of the test organism, at both concentrations (1 g/500 mL and 1 g/1000 mL) and at both times of exposure, thus being cytotoxic. All three plants promoted significant cytoprotective effect on the Paracetamol-treated meristematic root cells of A. cepa, thus showing, under the studied conditions, antimutagenic potential. Further studies using these plants should be carried out in order to properly define the cytotoxic and cytoprotective potential of pau-ferro’s pod, catingueira’s inner bark and flamboyazinho’s leaves.Os objetivos do presente trabalho foram avaliar, por meio das células meristemáticas de raízes de Allium cepa, nos tempos de exposição 24 e 48 horas, o potencial citotóxico de extratos aquosos, nas concentrações de 1g/500ml e 1g/1000ml, provenientes da entrecasca de Caesalpinia pyramidalis, da vagem de Caesalpinia ferrea e das folhas de Caesalpinia pulcherrima, e verificar o potencial modulador destes extratos frente as aberrações celulares induzidas por Paracetamol a partir dos seguintes grupos tratamentos:  controle negativo – água destilada; controle positivo – solução de Paracetamol a 0,008mg/ml, controle extrato aquoso da planta – fração aquosa de uma das plantas na concentração de 1g/500ml ou 1g/1000ml,  tratamento simultâneo - fração aquosa de uma das plantas na concentração de 1g/500ml ou 1g/1000ml associada a solução de Paracetamol a 0,008mg/ml. As raízes de A. cepa após os tratamentos foram fixadas em solução de Carnoy, hidrolisadas em ácido e coradas com orceína acética a 2%. Em seguida fez-se o esmagamento dos meristemas e montagem das lâminas. Analisou-se 5.000 células para cada grupo tratamento em microscopia de campo claro (40x), e utilizou-se o teste estatístico Qui-quadrado a 5% para análise dos dados. A partir dos resultados obtidos verificou-se que C. pyramidalis e C. ferrea nas duas concentrações e nos dois tempos de exposição avaliados tiveram efeito antiproliferativo significativo as células do organismo de prova utilizado, mostrando-se citotóxicas. Também foi observado que os respectivos tratamentos simultâneos de cada planta, nas duas concentrações e nos dois tempos de exposição avaliados, não diferiram do índice de divisão celular do seu respectivo controle extrato aquoso da planta. As três plantas promoveram efeito citoprotetor significativo as células meristemáticas de raízes de A. cepa tratadas com Paracetamol, demonstrando, nas condições analisadas, potencial antimutagênico. Os resultados obtidos aqui com A. cepa sugerem a realização de mais estudos, com outros sistemas testes e diferentes esquemas de tratamento, para assim se definir, com propriedade, o real potencial citotóxico e antimutagênico destas plantas

Action of Aqueous Extracts of Phyllanthus niruri L. (Euphorbiaceae) leaves on Meristematic Root Cells of Allium cepa L.

This study aimed to evaluate the effects of aqueous extracts of dried Phyllanthus niruri L. (stonebreaker) leaves on Allium cepa L. root meristem cells at four concentrations, 0.02 (usual concentration), 0.04, 0.06 and 0.08mg/mL and exposure times of 24 and 48 hours. For each concentration we used a group of five onion bulbs that were first embedded in distilled water and then transferred to their respective concentrations. The radicles were collected and fixed in acetic acid (3:1) for 24 hours. The slides were prepared by the crushing technique and stained with 2% acetic orcein. Cells were analyzed throughout the cell cycle, totaling 5000 for each control and exposure time. The calculated mitotic indices were subjected to the Chi-squared statistical analysis (p<0.05). From the results obtained it was observed that all four concentrations tested had significant antiproliferative effect on the cell cycle of this test system. We also found the presence of cellular aberrations such as colchicined metaphases, anaphasic and telophasic bridges, and micronuclei in the two exposure times for all concentrations evaluated. Therefore, under the conditions studied the concentrations of aqueous extracts of leaves of P. niruri showed to be cytotoxic and genotoxic