32 research outputs found
Extracellular matrix and nuclear abnormalities in skeletal muscle of a patient with Walker–Warburg syndrome caused by POMT1 mutation
AbstractWalker–Warburg syndrome (WWS) is an autosomal recessive disorder characterized by congenital muscular dystrophy, structural eye abnormalities and severe brain malformations. We performed an immunohistochemical and electron microscopy study of a muscle biopsy from a patient affected by WWS carrying a homozygous frameshift mutation in O-mannosyltransferase 1 gene (POMT1). α-Dystroglycan glycosylated epitope was not detected in muscle fibers and intramuscular peripheral nerves. Laminin α2 chain and perlecan were reduced in muscle fibers and well preserved in intramuscular peripheral nerves. The basal lamina in several muscle fibers showed discontinuities and detachment from the plasmalemma. Most nuclei, including myonuclei and satellite cell nuclei, showed detachment or complete absence of peripheral heterochromatin from the nuclear envelope. Apoptotic changes were detected in 3% of muscle fibers. The particular combination of basal lamina and nuclear changes may suggest that a complex pathogenetic mechanism, affecting several subcellular compartments, underlies the degenerative process in WWS muscle
A chemical survey of exoplanets with ARIEL
Thousands of exoplanets have now been discovered with a huge range of masses, sizes and orbits: from rocky Earth-like planets to large gas giants grazing the surface of their host star. However, the essential nature of these exoplanets remains largely mysterious: there is no known, discernible pattern linking the presence, size, or orbital parameters of a planet to the nature of its parent star. We have little idea whether the chemistry of a planet is linked to its formation environment, or whether the type of host star drives the physics and chemistry of the planet’s birth, and evolution. ARIEL was conceived to observe a large number (~1000) of transiting planets for statistical understanding, including gas giants, Neptunes, super-Earths and Earth-size planets around a range of host star types using transit spectroscopy in the 1.25–7.8 μm spectral range and multiple narrow-band photometry in the optical. ARIEL will focus on warm and hot planets to take advantage of their well-mixed atmospheres which should show minimal condensation and sequestration of high-Z materials compared to their colder Solar System siblings. Said warm and hot atmospheres are expected to be more representative of the planetary bulk composition. Observations of these warm/hot exoplanets, and in particular of their elemental composition (especially C, O, N, S, Si), will allow the understanding of the early stages of planetary and atmospheric formation during the nebular phase and the following few million years. ARIEL will thus provide a representative picture of the chemical nature of the exoplanets and relate this directly to the type and chemical environment of the host star. ARIEL is designed as a dedicated survey mission for combined-light spectroscopy, capable of observing a large and well-defined planet sample within its 4-year mission lifetime. Transit, eclipse and phase-curve spectroscopy methods, whereby the signal from the star and planet are differentiated using knowledge of the planetary ephemerides, allow us to measure atmospheric signals from the planet at levels of 10–100 part per million (ppm) relative to the star and, given the bright nature of targets, also allows more sophisticated techniques, such as eclipse mapping, to give a deeper insight into the nature of the atmosphere. These types of observations require a stable payload and satellite platform with broad, instantaneous wavelength coverage to detect many molecular species, probe the thermal structure, identify clouds and monitor the stellar activity. The wavelength range proposed covers all the expected major atmospheric gases from e.g. H2O, CO2, CH4 NH3, HCN, H2S through to the more exotic metallic compounds, such as TiO, VO, and condensed species. Simulations of ARIEL performance in conducting exoplanet surveys have been performed – using conservative estimates of mission performance and a full model of all significant noise sources in the measurement – using a list of potential ARIEL targets that incorporates the latest available exoplanet statistics. The conclusion at the end of the Phase A study, is that ARIEL – in line with the stated mission objectives – will be able to observe about 1000 exoplanets depending on the details of the adopted survey strategy, thus confirming the feasibility of the main science objectives.Peer reviewedFinal Published versio
Sepse: avaliação da qualidade do atendimento em setor de urgência e emergência: Sepsis: assessment of the quality of emergency and emergency care
A Sepse corresponde à presença de uma disfunção orgânica fatal provocada por uma resposta anormal do hospedeiro a um processo infeccioso, que pode progredir para um choque séptico. No decorrer dessa pesquisa, cuja metodologia foi a revisão integrativa de literatura, foram utilizados artigos científicos publicados em periódicos nacionais entre os anos de 2015 e 2022, retirados da base de dados Medline e Lilacs, sendo buscados a partir dos descritores: “Sepse”, “Qualidade do atendimento” e “Urgência e Emergência”. Com o objetivo de analisar a efetividade das ações de cuidados de Enfermagem aplicadas ao sepse adulto, a partir da análise de dados reunidos nesta revisão integrativa, foi possível concluir que a implantação de protocolos para o tratamento resultou em melhorias significativas nos indicadores de qualidade nos cuidados com a sepse, a exemplo da melhoria do fluxo e de atenção aos pacientes e redução da mortalidade nos setores de urgência e emergência
IMMAGINI DI SCIENZA NELLA DIDATTICA DEL PRIMO '900 - TAVOLE ENTOMOLOGICHE DELL'ISTITUTO DI ENTOMOLOGIA AGRARIA DI PISA
Se il rapporto tra Arte e Scienza ha riempito con parole migliaia di pagine di letteratura artistica; se ha coinvolto schiere di appassionati intellettuali, di estrazione scientifica e non solo umanistica; e ancora: se il confronto tra le due Culture ha brillantemente attraversato indenne ogni tentativo di conciliazione dei termini e altrettanto efficacemente superato l’estremismo di posizioni che le vorrebbero in competizione, una plausibile causa potrebbe essere cercata nell’originale prolificità di documenti che evidentemente deriva proprio dal loro confronto. Discussioni e confronti dunque che stimolano nuove curiosità e da queste, nuove idee; sono queste che dischiudono nuovi spazi e nuovi spiragli da cui affacciarsi e magari con sorpresa scoprire un più ampio raggio di orizzonte; quella porzione in più di paesaggio che sia al contempo finale approdo e nuovo impulso per successivi e stimolanti percorsi
Improved subpixel monitoring of seasonal snow cover: a case study in the Alps
International audienceThe snow coverage area (SCA) is one of the most important parameters for cryospheric studies. The use of remote sensing imagery can complement field measurements by providing means to derive SCA with a high temporal frequency and covering large areas. Images acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) are perhaps the most widely used data to retrieve SCA maps. Some MODIS derived algorithms are available for subpixel SCA estimation, as MODSCAG and MODImLab. Both algorithms make use of spectral unmixing techniques using a fixed set of snow, rocks and other materials spectra (endmembers). We aim to improve the performance of a modified version of MODIm-Lab algorithm by exploring advanced spectral unmixing techniques. Furthermore, we make use of endmember induction algorithms to obtain the endmembers from the data itself instead of using a fixed spectral library. We validate the proposed approach on a case study in the mountainous region of the Alps