905 resultados para Museum Exhibits


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Background: The temporal and geographical diversification of Neotropical insects remains poorly understood because of the complex changes in geological and climatic conditions that occurred during the Cenozoic. To better understand extant patterns in Neotropical biodiversity, we investigated the evolutionary history of three Neotropical swallowtail Troidini genera (Papilionidae). First, DNA-based species delimitation analyses were conducted to assess species boundaries within Neotropical Troidini using an enlarged fragment of the standard barcode gene. Molecularly delineated species were then used to infer a time-calibrated species-level phylogeny based on a three-gene dataset and Bayesian dating analyses. The corresponding chronogram was used to explore their temporal and geographical diversification through distinct likelihood-based methods. Results: The phylogeny for Neotropical Troidini was well resolved and strongly supported. Molecular dating and biogeographic analyses indicate that the extant lineages of Neotropical Troidini have a late Eocene (33-42 Ma) origin in North America. Two independent lineages (Battus and Euryades + Parides) reached South America via the GAARlandia temporary connection, and later became extinct in North America. They only began substantive diversification during the early Miocene in Amazonia. Macroevolutionary analysis supports the "museum model" of diversification, rather than Pleistocene refugia, as the best explanation for the diversification of these lineages. Conclusions: This study demonstrates that: (i) current Neotropical biodiversity may have originated ex situ; (ii) the GAARlandia bridge was important in facilitating invasions of South America; (iii) colonization of Amazonia initiated the crown diversification of these swallowtails; and (iv) Amazonia is not only a species-rich region but also acted as a sanctuary for the dynamics of this diversity. In particular, Amazonia probably allowed the persistence of old lineages and contributed to the steady accumulation of diversity over time with constant net diversification rates, a result that contrasts with previous studies on other South American butterflies.

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Abstract Background The current treatments for anxiety disorders and depression have multiple adverse effects in addition to a delayed onset of action, which has prompted efforts to find new substances with potential activity in these disorders. Citrus aurantium was chosen based on ethnopharmacological data because traditional medicine refers to the Citrus genus as useful in diminishing the symptoms of anxiety or insomnia, and C. aurantium has more recently been proposed as an adjuvant for antidepressants. In the present work, we investigated the biological activity underlying the anxiolytic and antidepressant effects of C. aurantium essential oil (EO), the putative mechanism of the anxiolytic-like effect, and the neurochemical changes in specific brain structures of mice after acute treatment. We also monitored the mice for possible signs of toxicity after a 14-day treatment. Methods The anxiolytic-like activity of the EO was investigated in a light/dark box, and the antidepressant activity was investigated in a forced swim test. Flumazenil, a competitive antagonist of benzodiazepine binding, and the selective 5-HT1A receptor antagonist WAY100635 were used in the experimental procedures to determine the mechanism of action of the EO. To exclude false positive results due to motor impairment, the mice were submitted to the rotarod test. Results The data suggest that the anxiolytic-like activity observed in the light/dark box procedure after acute (5 mg/kg) or 14-day repeated (1 mg/kg/day) dosing was mediated by the serotonergic system (5-HT1A receptors). Acute treatment with the EO showed no activity in the forced swim test, which is sensitive to antidepressants. A neurochemical evaluation showed no alterations in neurotransmitter levels in the cortex, the striatum, the pons, and the hypothalamus. Furthermore, no locomotor impairment or signs of toxicity or biochemical changes, except a reduction in cholesterol levels, were observed after treatment with the EO. Conclusion This work contributes to a better understanding of the biological activity of C. aurantium EO by characterizing the mechanism of action underlying its anxiolytic-like activity.

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Reflections on the university campus usually focus on its relevancy as a research and teaching area; however, the need for preservation, protection, maintenance and cleaning only become visible in the event of inadequacy or lack thereof. The aim of this study is to address the characteristics of the preservation and security measures performed at the Science and Technology Park of the University of São Paulo (Parque de Ciência e Tecnologia da Universidade de São Paulo), agency subjected to the Dean’s Office for Culture and University Extension (Pró-Reitoria de Cultura e Extensão Universitária). Because of its history and location, the Park requires special care. The Park’s land formerly housed the Astronomical Observatory of São Paulo and the Institute of Astronomy and Geophysics of the University of São Paulo (Instituto de Astronomia e Geofísica – IAG-USP), within the Fontes do Ipiranga State Park (Parque Estadual das Fontes do Ipiranga – PEFI), in the city of São Paulo. Preservation and reconversion activities relative to historical buildings are developed at the Park. The institution’s location and its specificities require security in its borders, as well as in relation to the users of the park.

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A proposal for a virtual museum of computer science

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La presente tesi di laurea si concentra sulla localizzazione in inglese di varie sezioni del nuovo sito web della Pinacoteca di Brera. Il progetto di localizzazione è stato contestualizzato da un lato all’interno della letteratura sulla comunicazione museale, e dall’altro sulla comunicazione web, per poter avanzare proposte di miglioramento alla luce di ricerche nel campo della SEO (Search Engine Optimization). Lo studio della comunicazione museale si è arricchito grazie all’esperienza di documentazione presso la University of Leicester (UK). La tesi mira a porre le basi per la produzione di contenuti museali adatti ad una lettura sul web, in modo da offrire non solo una traduzione ben fatta dal punto di vista linguistico e culturale, ma anche facilmente fruibile per un utente online e reperibile attraverso motori di ricerca. L’elaborato intende fornire ai musei italiani alcuni spunti di riflessione circa possibili miglioramenti delle proprie piattaforme online grazie alla localizzazione e ad un’analisi approfondita dei contenuti web secondo principi di usabilità e visibilità. Il capitolo 1 introduce la letteratura sugli studi museali, prestando particolare attenzione alla comunicazione. Il capitolo 2 fornisce una panoramica generale sul web: vengono suggerite buone pratiche di web writing, analizzate le strategie di SEO per migliorare la visibilità dei siti e delineato le principali caratteristiche del processo di localizzazione. Il capitolo 3 riunisce i due universi finora esplorati individualmente, ovvero i musei e il web, concentrandosi sulla comunicazione online dei musei e concludendo con uno schema di valutazione dei siti dei musei. Il capitolo 4 applica le strategie precedentemente discusse al caso specifico della Pinacoteca di Brera, concentrandosi sulla valutazione del sito, sulla localizzazione di alcune sezioni e sulla proposta di strategie SEO. Infine, il capitolo 5 tira le fila dell’intero lavoro mettendo in evidenza i principali risultati ottenuti.

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Garlic extracts have been shown to decrease drug exposure for saquinavir, a P-glycoprotein and cytochrome P450 3A4 substrate. In order to explore the underlying mechanisms and to study the effects of garlic on pre-systemic drug elimination, healthy volunteers were administered garlic extract for 21 days. Prior to and at the end of this period, expression of duodenal P-glycoprotein and cytochrome P450 3A4 protein were assayed and normalized to villin, while hepatic cytochrome P450 3A4 function and simvastatin, pravastatin and saquinavir pharmacokinetics were also evaluated. Ingestion of garlic extract increased expression of duodenal P-glycoprotein to 131% (95% CI, 105-163%), without increasing the expression of cytochrome P450 3A4 which amounted to 87% (95% CI, 67-112%), relative to baseline in both cases. For the erythromycin breath test performed, the average result was 96% (95% CI, 83-112%). Ingestion of garlic extract had no effect on drug and metabolite AUCs following a single dose of simvastatin or pravastatin, although the average area under the plasma concentration curve (AUC) of saquinavir decreased to 85% (95% CI, 66-109%), and changes in intestinal P-glycoprotein expression negatively correlated with this change. In conclusion, garlic extract induces intestinal expression of P-glycoprotein independent of cytochrome P450 3A4 in human intestine and liver.

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Cupiennin 1a, a cytolytic peptide isolated from the venom of the spider Cupiennius salei, exhibits broad membranolytic activity towards bacteria, trypanosomes, and plasmodia, as well as human blood and cancer cells. In analysing the cytolytic activity of synthesised all-d- and all-l-cupiennin 1a towards pro- and eukaryotic cells, a stereospecific mode of membrane destruction could be excluded. The importance of negatively charged sialic acids on the outer leaflet of erythrocytes for the binding and haemolytic activity of l-cupiennin 1a was demonstrated. Reducing the overall negative charges of erythrocytes by partially removing their sialic acids or by protecting them with tri- or pentalysine results in reduced haemolytic activity of the peptide.