67 research outputs found

    Locally conformal SKT structures

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    A Hermitian metric on a complex manifold is called SKT (strong K\"ahler with torsion) if the Bismut torsion 33-form HH is closed. As the conformal generalization of the SKT condition, we introduce a new type of Hermitian structure, called \emph{locally conformal SKT} (or shortly LCSKT). More precisely, a Hermitian structure (J,g)(J,g) is said to be LCSKT if there exists a closed non-zero 11-form α\alpha such that dH=α∧Hd H = \alpha \wedge H. In the paper we consider non-trivial LCSKT structures, i.e. we assume that dH≠0d H \neq 0 and we study their existence on Lie groups and their compact quotients by lattices. In particular, we classify 6-dimensional nilpotent Lie algebras admitting a LCSKT structure and we show that, in contrast to the SKT case, there exists a 66-dimensional 33-step nilpotent Lie algebra admitting a non-trivial LCSKT structure. Moreover, we show a characterization of even dimensional almost abelian Lie algebras admitting a non-trivial LCSKT structure, which allows us to construct explicit examples of 66-dimensional unimodular almost abelian Lie algebras admitting a non-trivial LCSKT structure. The compatibility between the LCSKT and the balanced condition is also discussed, showing that a Hermitian structure on a 6-dimensional nilpotent or a 2n2n-dimensional almost abelian Lie algebra cannot be simultaneously LCSKT and balanced, unless it is K\"{a}hler.Comment: references update

    Locally conformal SKT structures

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    A Hermitian metric on a complex manifold is called SKT (strong K ̈ahler with torsion) if the Bismut torsion 3-form H is closed. As the conformal generalization of the SKT condition, we introduce a new type of Hermitian structure, called locally conformal SKT (or shortly LCSKT). More precisely, a Hermitian structure (J, g) is said to be LCSKT if there exists a closed nonzero 1-form α such that dH = α∧H. In this paper, we consider nontrivial LCSKT structures, i.e. we assume that dH ̸= 0 and we study their existence on Lie groups and their compact quotients by lattices. In particular, we classify six-dimensional nilpotent Lie algebras admitting a LCSKT structure and we show that, in contrast to the SKT case, there exists a six-dimensional 3- step nilpotent Lie algebra admitting a nontrivial LCSKT structure. Moreover, we show a characterization of even dimensional almost abelian Lie algebras admitting a nontrivial LCSKT structure, which allows us to construct explicit examples of six-dimensional unimodular almost abelian Lie algebras admitting a nontrivial LCSKT structure. The compatibility between the LCSKT and the balanced condition is also discussed, showing that a Hermitian structure on a six-dimensional nilpotent or a 2n-dimensional almost abelian Lie algebra cannot be simultaneously LCSKT and balanced, unless it is K ̈ahler.By GNSAGA of INdAM, by the project PRIN 2017 “Real and Complex Manifolds: Topology, Geometry and Holomorphic Dynamics and by a grant from the Simons Foundation (#944448

    A utilização de objetos de aprendizagem e modelagem matemática para o ensino de probabilidade

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    Orientador : Roberto de Fino BentesArtigo (especialização) - Universidade Federal do Paraná, Setor de Educação Profissional e Tecnológica, Curso de Especialização em Mídias Integradas na Educação.Inclui referência

    Recovery of humic acids from anaerobic sewage sludge: Extraction, characterization and encapsulation in alginate beads

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    Wastewater production is rising all over the world and one of the most difficult problems is the disposal of sewage sludge (SS). It is known that SS contains certain quantities of added-value compounds, such as humic acids (HA) which in turn have beneficial effects on soil quality and plant growth. On the other hand, SS can retain many pollutants, such as heavy metals. The present work aimed to implement an HA alkaline extraction protocol from anaerobic sewage sludge (ASS). Subsequently, the HA were quantified in ASS, in HA extract and in commercial HA, used as a benchmark, which gave results of 12.53%, 26.87% and 77.87% (on dry matter basis), respectively. FESEM and EDX analyses on lyophilized HA extract confirmed that no heavy metals had passed into the extract. Afterwards, in order to allow controlled release of the HA in soils, alginate beads containing the HA extract were created. Finally, a pot experiment in a greenhouse was performed using Chilean lettuce plants (Lactuca sativa L.) treated with alginate-HA extract beads. At the end of the greenhouse experiments, the hypogean dry biomass of the treated plants was significantly higher than for non-treated plants. The relevance of this study relies not only on the exploitation of green chemistry principles, by converting a waste stream into a high-value product, but also on the application of an approach following a circular economy model

    Evolución de la función renal de pacientes portadores del Virus de la Inmunodeficiencia Humana/ Síndrome de la Inmunodeficiencia Adquirida

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    OBJETIVO: Avaliar a evolução da função renal em pacientes portadores do Vírus da Imunodeficiência Humana que iniciaram acompanhamento no Centro de Controle de Doenças Infecciosas do Hospital São Paulo/ Universidade Federal de São Paulo. MÉTODOS: Estudo retrospectivo realizado através da análise de 200 prontuários selecionados de forma aleatória. RESULTADOS: Perfil predominante masculino, cor branca, idade média de 45 anos, mais de 50 meses de diagnóstico, co-morbidades adquiridas variando de zero a nove doenças, creatinina média de 0,93mg/dl e a grande maioria realizando tratamento medicamentoso. CONCLUSÃO: O grupo analisado não mostrou alteração significativa em relação à função renal entre a primeira e a última consulta.OBJECTIVE: To evaluate the renal function in patients with Human Immunodeficiency Virus who were attending the Center for Infectious Diseases Control of the São Paulo Hospital of the Federal University of São Paulo. METHODS: This retrospective study consisted of the review of 200 randomly selected medical records. RESULTS: Patients were predominant white males with a mean age of 45 years. They had been diagnosed with the disease over 50 months ago, had from 0 to up 9 comorbidities, and a mean creatinine of .93mg/dl. The majority of patients were receiving antiviral medication. CONCLUSION: There was no significant alteration in renal function in the patients between the first and last visit.OBJETIVO: Evaluar la evolución de la función renal en pacientes portadores del Virus de la Inmunodeficiencia Humana que iniciaron acompañamiento en el Centro de Control de Enfermedades Infecciosas del Hospital Sao Paulo/ Universidad Federal de Sao Paulo. MÉTODOS: Estudio retrospectivo realizado a través del análisis de 200 historias clínicas seleccionadas de forma aleatoria. RESULTADOS: Perfil predominante masculino, raza blanca, edad promedio de 45 años, más de 50 meses de diagnóstico, comorbidades adquiridas variando de cero a nueve enfermedades, creatinina promedio de 0,93mg/dl y la gran mayoría realizando tratamiento medicamentoso. CONCLUSIÓN: El grupo analizado no mostró alteración significativa en relación a la función renal entre la primera y la última consulta

    Tracking the immunopathological response to Pseudomonas aeruginosa during respiratory infections

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    Repeated cycles of infections, caused mainly by Pseudomonas aeruginosa, combined with a robust host immune response and tissue injury, determine the course and outcome of cystic fibrosis (CF) lung disease. As the disease progresses, P. aeruginosa adapts to the host modifying dramatically its phenotype; however, it remains unclear whether and how bacterial adaptive variants and their persistence influence the pathogenesis and disease development. Using in vitro and murine models of infection, we showed that P. aeruginosa CF-adaptive variants shaped the innate immune response favoring their persistence. Next, we refined a murine model of chronic pneumonia extending P. aeruginosa infection up to three months. In this model, including CFTR-deficient mice, we unveil that the P. aeruginosa persistence lead to CF hallmarks of airway remodelling and fibrosis, including epithelial hyperplasia and structure degeneration, goblet cell metaplasia, collagen deposition, elastin degradation and several additional markers of tissue damage. This murine model of P. aeruginosa chronic infection, reproducing CF lung pathology, will be instrumental to identify novel molecular targets and test newly tailored molecules inhibiting chronic inflammation and tissue damage processes in pre-clinical studies

    Anterior pituitary gland synthesises dopamine from l-3,4-dihydroxyphenylalanine (l-dopa)

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    Prolactin (PRL) is a hormone principally secreted by lactotrophs of the anterior pituitary gland. Although the synthesis and exocytosis of this hormone are mainly under the regulation of hypothalamic dopamine (DA), the possibility that the anterior pituitary synthesises this catecholamine remains unclear. The present study aimed to determine if the anterior pituitary produces DA from the precursor l-3,4-dihydroxyphenylalanine (l-dopa). Accordingly, we investigated the expression of aromatic l-amino acid decarboxylase (AADC) enzyme and the transporter vesicular monoamine transporter 2 (VMAT2) in the anterior pituitary, AtT20 and GH3 cells by immunofluorescence and western blotting. Moreover, we investigated the production of DA from l-dopa and its release in vitro. Then, we explored the effects of l-dopa with respect to the secretion of PRL from anterior pituitary fragments. We observed that the anterior pituitary, AtT20 and GH3 cells express both AADC and VMAT2. Next, we detected an increase in DA content after anterior pituitary fragments were incubated with l-dopa. Also, the presence of l-dopa increased DA levels in incubation media and reduced PRL secretion. Likewise, the content of cellular DA increased after AtT20 cells were incubated with l-dopa. In addition, l-dopa reduced corticotrophin-releasing hormone-stimulated adrenocorticotrophic hormone release from these cells after AADC activity was inhibited by NSD-1015. Moreover, DA formation from l-dopa increased apoptosis and decreased proliferation. However, in the presence of NSD-1015, l-dopa decreased apoptosis and increased proliferation rates. These results suggest that the anterior pituitary synthesises DA from l-dopa by AADC and this catecholamine can be released from this gland contributing to the control of PRL secretion. In addition, our results suggest that l-dopa exerts direct actions independently from its metabolisation to DA.Fil: Orrillo, Santiago Jordi. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: de Dios, Nataly. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Asad, Antonela Sofía. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: de Fino, Fernanda Teresa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Imsen, Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Romero, Ana Clara. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Zarate, Sandra Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Ferraris, Maria Jimena. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Pisera, Daniel Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; Argentin

    IL-17A impairs host tolerance during airway chronic infection by Pseudomonas aeruginosa

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    Resistance and tolerance mechanisms participate to the interplay between host and pathogens. IL-17-mediated response has been shown to be crucial for host resistance to respiratory infections, whereas its role in host tolerance during chronic airway colonization is still unclear. Here, we investigated whether IL-17-mediated response modulates mechanisms of host tolerance during airways chronic infection by P. aeruginosa. First, we found that IL-17A levels were sustained in mice at both early and advanced stages of P. aeruginosa chronic infection and confirmed these observations in human respiratory samples from cystic fibrosis patients infected by P. aeruginosa. Using IL-17a(-/-) or IL-17ra(-/-) mice, we found that the deficiency of IL-17A/IL-17RA axis was associated with: i) increased incidence of chronic infection and bacterial burden, indicating its role in the host resistance to P. aeruginosa; ii) reduced cytokine levels (KC), tissue innate immune cells and markers of tissue damage (pro-MMP-9, elastin degradation, TGF-β1), proving alteration of host tolerance. Blockade of IL-17A activity by a monoclonal antibody, started when chronic infection is established, did not alter host resistance but increased tolerance. In conclusion, this study identifies IL-17-mediated response as a negative regulator of host tolerance during P. aeruginosa chronic airway infection

    CAESAR: Space Weather archive prototype for ASPIS

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    The project CAESAR (Comprehensive spAce wEather Studies for the ASPIS prototype Realization) is aimed to tackle all the relevant aspects of Space Weather (SWE) and realize the prototype of the scientific data centre for Space Weather of the Italian Space Agency (ASI) called ASPIS (ASI SPace Weather InfraStructure). This contribution is meant to bring attention upon the first steps in the development of the CAESAR prototype for ASPIS and will focus on the activities of the Node 2000 of CAESAR, the set of Work Packages dedicated to the technical design and implementation of the CAESAR ASPIS archive prototype. The product specifications of the intended resources that will form the archive, functional and system requirements gathered as first steps to seed the design of the prototype infrastructure, and evaluation of existing frameworks, tools and standards, will be presented as well as the status of the project in its initial stage.Comment: 4 pages, 2 figures, ADASS XXXII (2022) Proceeding
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