3,807 research outputs found
Fossil bubble structure related to microbial activity coeval with the middle Ediacaran Oceanic Oxygenation Event in the Tandilia System
The well-preserved limestone succession, Loma Negra Formation (~40 m), in the Tandilia System was deposited in a shallow carbonate ramp under low energy conditions. The evolution in the depositional settings of the unit was indicated as deepening upwards varying from shallow-middle to outer ramp environment. The limestone fabric is assumed as the product of biologically controlled precipitation of micrite, where the terrigenous supply was limited. From detailed meso- and microscopic descriptions it is possible to recognize microbially induced sedimentary structures ?MISS? represented by typical microtextures related to microbial activity that appear represented throughout the entire formation. In addition, micro-stromatolites are observed in the unit associated with the microbial mats showing micro-columnar conical to domical morphologies.In the basal and middle Loma Negra Formation, hemispherical structures are recognized in the bed-tops and interpreted as bubbles-like and gas escape features associated with the microbial mat interaction. Their morphology is compared with oxygen bubbles produced by modern experimental modelling with photosynthetic cyanobacteria microbial mats. Moreover, hemispherical structures are associated with increasing gas pressure lifting grains and the organic components to the surface.This paper provides evidence to understand the possible causal relationship between microbial activity and seawater oxygenation. The high oxygen production revealed by geochemistry proxies and here proposed as probably associated with photosynthetic microbial activity might be a plausible explanation for the record of the documented Middle Ediacaran Oceanic Oxygenation Event in the Loma Negra Formation.Fil: Arrouy, Maria Julia. Comisión de Investigaciones Científicas de la Provincia de Buenos Aires. Instituto de Hidrología de Llanuras "Dr. Eduardo Jorge Usunoff". - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Instituto de Hidrología de Llanuras "Dr. Eduardo Jorge Usunoff". - Universidad Nacional del Centro de la Provincia de Buenos Aires. Instituto de Hidrología de Llanuras "Dr. Eduardo Jorge Usunoff"; ArgentinaFil: Gómez Peral, Lucia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; ArgentinaFil: Penzo, Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; ArgentinaFil: Ferreyra, Camila. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; ArgentinaFil: Poire, Daniel Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; Argentin
Controls on the dedolomitization of top of Villa Mónica Formation, Tandilia System
Dedolomitization is the process of replacement of dolomite by calcite which mostly occurs under meteoric water influence. The shallow marine deposits of the Villa Mónica Formation (VMF) (~1150-720 Ma) constitute here is a good example of where to study this process. VMF is the older unit of the sedimentary basin infill in Tandilia System (Buenos Aires, Argentina), and it is formed by a lower section (22 m) mainly composed of quartz-arkosic sandstones, and an upper mainly dolomitic section (36-52 m) with thin interbedded green claystone levels and ending with red claystone and purple marl. The contact between the top of VMF and the base of the Colombo Formation is an erosive surface. Previous studies indicate that the VMF was affected by deep burial diagenesis followed by telogenesis. However, the expression of the weathering processes over the dolostones is poorly known. Thus, the proposal of this work is to recognize and characterize features related to weathering processes in the last meters of the upper section of the VMF.Fil: Ferreyra, Camila. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; ArgentinaFil: Gómez Peral, Lucia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; ArgentinaFil: Raigemborn, María Sol. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; ArgentinaFil: Arrouy, Maria Julia. Comisión de Investigaciones Científicas de la Provincia de Buenos Aires. Instituto de Hidrología de Llanuras "Dr. Eduardo Jorge Usunoff". - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Instituto de Hidrología de Llanuras "Dr. Eduardo Jorge Usunoff". - Universidad Nacional del Centro de la Provincia de Buenos Aires. Instituto de Hidrología de Llanuras "Dr. Eduardo Jorge Usunoff"; ArgentinaFil: Penzo, Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; ArgentinaFil: Sial, Alcides N.. Universidad Federal Rural Pernambuco; BrasilXVIII Reunión Argentina de Sedimentología y IX Congreso Latinoamericano de SedimentologíaLa PlataArgentinaAsociación Argentina de Sedimentologí
Cyclic nucleotide signalling in malaria parasites.
The cyclic nucleotides 3', 5'-cyclic adenosine monophosphate (cAMP) and 3', 5'-cyclic guanosine monophosphate (cGMP) are intracellular messengers found in most animal cell types. They usually mediate an extracellular stimulus to drive a change in cell function through activation of their respective cyclic nucleotide-dependent protein kinases, PKA and PKG. The enzymatic components of the malaria parasite cyclic nucleotide signalling pathways have been identified, and the genetic and biochemical studies of these enzymes carried out to date are reviewed herein. What has become very clear is that cyclic nucleotides play vital roles in controlling every stage of the complex malaria parasite life cycle. Our understanding of the involvement of cyclic nucleotide signalling in orchestrating the complex biology of malaria parasites is still in its infancy, but the recent advances in our genetic tools and the increasing interest in signalling will deliver more rapid progress in the coming years
The nucleolar size is associated to the methylation status of ribosomal DNA in breast carcinomas.
BACKGROUND: There is a body of evidence that shows a link between tumorigenesis
and ribosome biogenesis. The precursor of mature 18S, 28S and 5.8S ribosomal RNAs
is transcribed from the ribosomal DNA gene (rDNA), which exists as 300-400 copies
in the human diploid genome. Approximately one half of these copies are
epigenetically silenced, but the exact role of epigenetic regulation on ribosome
biogenesis is not completely understood. In this study we analyzed the
methylation profiles of the rDNA promoter and of the 5' regions of 18S and 28S in
breast cancer.
METHODS: We analyzed rDNA methylation in 68 breast cancer tissues of which the
normal counterpart was partially available (45/68 samples) using the MassARRAY
EpiTYPER assay, a sensitive and quantitative method with single base resolution.
RESULTS: We found that rDNA locus tended to be hypermethylated in tumor compared
to matched normal breast tissues and that the DNA methylation level of several
CpG units within the rDNA locus was associated to nuclear grade and to nucleolar
size of tumor tissues. In addition we identified a subgroup of samples in which
large nucleoli were associated with very limited or absent rDNA hypermethylation
in tumor respect to matched normal tissue.
CONCLUSIONS: In conclusion, we suggest that rDNA is an important target of
epigenetic regulation in breast tumors and that rDNA methylation level is
associated to nucleolar size
Editorial
Editorial da Revista Palíndromo vol. 14 n. 32 janeiro-abril 2022
Dossiê Formação de professores de artes no brasil: problematizações a partir do projeto em rede observatório
Organizadoras:
Profa. Dra. Maria Cristina da Rosa Fonseca da Silva (UDESC)
Profa. Dra. Vera Fernandez Penzo (UFMS
Plasmodium subtilisin-like protease 1 (SUB1): insights into the active-site structure, specificity and function of a pan-malaria drug target.
Release of the malaria merozoite from its host erythrocyte (egress) and invasion of a fresh cell are crucial steps in the life cycle of the malaria pathogen. Subtilisin-like protease 1 (SUB1) is a parasite serine protease implicated in both processes. In the most dangerous human malarial species, Plasmodium falciparum, SUB1 has previously been shown to have several parasite-derived substrates, proteolytic cleavage of which is important both for egress and maturation of the merozoite surface to enable invasion. Here we have used molecular modelling, existing knowledge of SUB1 substrates, and recombinant expression and characterisation of additional Plasmodium SUB1 orthologues, to examine the active site architecture and substrate specificity of P. falciparum SUB1 and its orthologues from the two other major human malaria pathogens Plasmodium vivax and Plasmodium knowlesi, as well as from the rodent malaria species, Plasmodium berghei. Our results reveal a number of unusual features of the SUB1 substrate binding cleft, including a requirement to interact with both prime and non-prime side residues of the substrate recognition motif. Cleavage of conserved parasite substrates is mediated by SUB1 in all parasite species examined, and the importance of this is supported by evidence for species-specific co-evolution of protease and substrates. Two peptidyl alpha-ketoamides based on an authentic PfSUB1 substrate inhibit all SUB1 orthologues examined, with inhibitory potency enhanced by the presence of a carboxyl moiety designed to introduce prime side interactions with the protease. Our findings demonstrate that it should be possible to develop 'pan-reactive' drug-like compounds that inhibit SUB1 in all three major human malaria pathogens, enabling production of broad-spectrum antimalarial drugs targeting SUB1
Observatório da Formação de Professores de Artes Visuais: um estudo da materialidade das condições de trabalho do professor de Arte no Brasil
This study aims to systematize the bases for analysis of the 803 questionnaires that were answered by Basic Education teachers who work teaching art in school. The team network project Observatory of Teacher Education in the field of Arts Education: Comparative Studies Brazil and Argentina, from two working groups, organized the process of data analysis. The bibliographic study was used as a research procedure, as well as the analysis of the methodological process of data collection and pre-organization, as a phase prior to the analysis. The bibliographical study intended to reflect on the materiality of the working conditions of the art teacher. As a result of this phase, it was possible to perceive the need for data formatting to use the NVIVO software, as well as identifying that the precariousness of work and lack of public policies are fundamental elements for the analysis process, because it directly invol[1]ves the pedagogical work. It is true that the appreciation of the teacher and of art and the investment in pedagogical work are constituted both by legal aspects and by the praxis that develops within the scope of the characteristics of teaching. However, investment in professional qualification, in access to art and culture, as well as in working conditions, are determining factors for professionals in the field of arts at school to fulfill their social role. Therefore, educational praxis cannot be dissociated from the conditions that the state performs in fulfilling its obligations related to the quality of Public Education.Este estudio tiene como objetivo sistematizar las bases para el análisis de los 803 cuestionarios que fueron respondidos por docentes que laboran con enseñanza de Educación Artística en Educación Básica en escuelas. El equipo del proyecto en la red Observatorio de Formación Docente en el campo de la Educación Artística: Estudios Comparados Brasil y Argentina, a partir de dos grupos de trabajo, organizó el proceso de análisis de datos. El estudio bibliográfico se utilizó como procedimiento de investigación, así como el análisis del proceso metodológico de recolección y pre organización de datos, como fase previa al análisis. El estudio bibliográfico pretendía reflexionar sobre la materialidad de las condiciones laborales del profesor de arte. Como resultado de esta fase, se pudo percibir la necesidad de formateo de datos para el uso del software NVIVO, así como identificar que la precariedad del trabajo y la falta de políticas públicas son elementos fundamentales para el proceso de análisis, porque implica directamente el trabajo pedagógico. Es cierto que la valoración del docente y el arte, así como la inversión en el trabajo pedagógico, están constituidos tanto por los aspectos legales como por la praxis que se desarrolla en el ámbito de las características de la docencia. Sin embargo, la inversión en la capacitación de los profesionales, en las políticas de acceso al arte y la cultura, así como en las condiciones laborales, son factores determinantes para que los docentes de arte cumplan con su rol social. Por tanto, la praxis educativa no puede disociarse de las condiciones que desempeña el Estado en el cumplimiento de sus obligaciones vinculadas a la calidad de la Educación Pública.O presente estudo tem como objetivo sistematizar as bases para análise dos 803 questionários que foram respondidos por professores da Educação Básica que atuam nas escolas ensinando artes. A equipe do projeto em rede Observatório da Formação de Professores no âmbito do Ensino de Artes: Estudos comparados Brasil e Argentina, a partir de dois grupos de trabalho, organizou o processo de análise dos dados. Utilizou como procedimento de pesquisa o estudo bibliográfico, também a análise do processo metodológico de coleta e pré-organização dos dados, como fase anterior à análise. O estudo bibliográfico pretendeu refletir acerca da materialidade das condições de trabalho do professor de arte. Como resultado dessa fase, foi possível perceber a necessidade de formatação dos dados para a utilização do software NVIVO, assim como identificou que a precarização do trabalho e a falta de políticas públicas são elementos fundamentais para o processo de análise, porque implica diretamente no trabalho pedagógico. É certo que a valorização do professor e da arte e ainda o investimento no trabalho pedagógico são constituídos tanto por aspectos legais quanto pela práxis que se desenvolve no âmbito das características da docência. No entanto, o investimento na qualificação dos profissionais, em políticas de acesso à arte e à cultura, bem como nas condições de trabalho são fatores determinantes para que professores de arte cumpram com o seu papel social. Por isso, a práxis educativa não pode ser dissociada das condições que o estado desempenha no cumprimento de suas obrigações vinculadas à qualidade da Educação Pública
Instrucció i aprenentatge en Ciències de la Salut. IASC
Podeu consultar la Setena trobada de professorat de Ciències de la Salut completa a: http://hdl.handle.net/2445/4335
Incorporació de metodologies d'e-learning per a l'aprenentatge de la farmacologia
Podeu consultar la Vuitena trobada de professorat de Ciències de la Salut completa a: http://hdl.handle.net/2445/66524Introducció: En el nostre grup d’innovació docent per tal d’aconseguir una docència funcional, aquella en que l’alumne és capaç de fer servir els seus coneixements en situacions el més semblants a la realitat professional, utilitzem les següents eines: resolució d’activitats d’aplicació i problemes, treball en grup i aprenentatge col·laboratiu. D’aquesta manera el professorat esdevé una figura de referència per discutir els punts crítics i problemàtics de l’aprenentatge i no es limita a ser només una simple font d’informació. Considerem que l’ús de les TICs ens pot ésser de gran utilitat per assolir, al màxim nivell possible, la docència funcional
Targeting the Malaria Parasite cGMP-Dependent Protein Kinase to Develop New Drugs.
The single-celled apicomplexan parasite Plasmodium falciparum is responsible for the majority of deaths due to malaria each year. The selection of drug resistance has been a recurring theme over the decades with each new drug that is developed. It is therefore crucial that future generations of drugs are explored to tackle this major public health problem. Cyclic GMP (cGMP) signaling is one of the biochemical pathways that is being explored as a potential target for new antimalarial drugs. It has been shown that this pathway is essential for all of the key developmental stages of the complex malaria parasite life cycle. This gives hope that targeting cGMP signaling might give rise to drugs that treat disease, block its transmission and even prevent the establishment of infection. Here we review previous work that has been carried out to develop and optimize inhibitors of the cGMP-dependent protein kinase (PKG) which is a critical regulator of the malaria parasite life cycle
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