444 research outputs found
Comparison of Flight Simulators Based on Human Motion Perception Metrics
In flight simulation, motion filters are used to transform aircraft motion into simulator motion. When looking for the best match between visual and inertial amplitude in a simulator, researchers have found that there is a range of inertial amplitudes, rather than a single inertial value, that is perceived by subjects as optimal. This zone, hereafter referred to as the optimal zone, seems to correlate to the perceptual coherence zones measured in flight simulators. However, no studies were found in which these two zones were compared. This study investigates the relation between the optimal and the coherence zone measurements within and between different simulators. Results show that for the sway axis, the optimal zone lies within the lower part of the coherence zone. In addition, it was found that, whereas the width of the coherence zone depends on the visual amplitude and frequency, the width of the optimal zone remains constant
Biomanipulação nas lagoas das Sete Cidades e das Furnas (São Miguel, Açores)
XII congresso da Associação Espanhola de Limnologia/IV Congresso Ibérico de Limnologia, organizado pela Associação Espanhola de Limnologia, de 5 a 9 de Julho de 2004 no Porto, Portugal.A qualidade da água de um sistema lacustre de baixa profundidade não deve ser avaliada apenas segundo a concentração de nutrientes, uma vez que esses sistemas podem existir em dois estados alternativos: um de água transparente, dominado por macrófitos, e outro de água turva dominado por fitoplâncton
Sectional anatomic and magnetic resonance imaging features of coelomic structures of loggerhead sea turtles
Efficient extraction of the RuBisCO enzyme from spinach leaves using aqueous solutions of biocompatible ionic liquids
Ribulose-1,5-biphosphate carboxylase/oxygenase (RuBisCO) is the most abundant protein
on the planet, being present in plants, algae and various species of bacteria, with application in the
pharmaceutical, chemical, cosmetic and food industries. However, current extraction methods of
RuBisCO do not allow high yields of extraction. Therefore, the development of an efficient and
selective RuBisCOs’ extraction method is required. In this work, aqueous solutions of biocompatible
ionic liquids (ILs), i.e., ILs derived from choline and analogues of glycine-betaine, were applied
in the RuBisCO’s extraction from spinach leaves. Three commercial imidazolium-based ILs were
also investigated for comparison purposes. To optimize RuBisCO’s extraction conditions, response
surface methodology was applied. Under optimum extraction conditions, extraction yields of 10.92
and 10.57 mg of RuBisCO/g of biomass were obtained with the ILs cholinium acetate ([Ch][Ac])
and cholinium chloride ([Ch]Cl), respectively. Circular dichroism (CD) spectroscopy results show
that the secondary structure of RuBisCO is better preserved in the IL solutions when compared to
the commonly used extraction solvent. The obtained results indicate that cholinium-based ILs are a
promising and viable alternative for the extraction of RuBisCO from vegetable biomass.publishe
A construção do mercado para o café em Alto Paraíso de Goiás.
Este estudo apresenta os principais resultados da análise de como habitantes de Alto Paraíso de Goiás estão buscando alternativas para o desenvolvimento sustentável do município, por meio da implantação, pela Embrapa, de projeto relativo ao resgate do café. A mineração e as atividades agropecuárias foram exercidas na região até os anos 60, quando a atividade principal passou a ser o turismo, a partir da criação do Parque Nacional da Chapada dos Veadeiros e da inauguração de Brasília. Em 2000, o fluxo de turistas decaiu devido a problemas relativos à saúde pública, acarretando estagnação da economia local. Nos últimos anos, produtores familiares despertaram para a existência, ali, de um café que pode ser comercializado em nichos de mercado de grãos especiais: orgânicos e de origem definida, e buscaram, na Embrapa, o desenvolvimento de projeto de pesquisa. O estudo na região revelou que por meio do desvelamento de valores - história, cultura e tradições - é possível estabelecer estratégia mais eficiente de busca de mercado, a partir da experiência revelada no trabalho concreto e na cultura dos produtores. E que o desenvolvimento rural deve ser buscado por meio do desenvolvimento de atividades da nova ruralidade e da aplicação de abordagem territorial de desenvolvimento
Crosstalk between glial and glioblastoma cells triggers the "go-or-grow" phenotype of tumor cells
Background: Glioblastoma (GBM), the most malignant primary brain tumor, leads to poor and unpredictable clinical outcomes. Recent studies showed the tumor microenvironment has a critical role in regulating tumor growth by establishing a complex network of interactions with tumor cells. In this context, we investigated how GBM cells modulate resident glial cells, particularly their paracrine activity, and how this modulation can influence back on the malignant phenotype of GBM cells.
Methods: Conditioned media (CM) of primary mouse glial cultures unexposed (unprimed) or exposed (primed) to the secretome of GL261 GBM cells were analyzed by proteomic analysis. Additionally, these CM were used in GBM cells to evaluate their impact in glioma cell viability, migration capacity and activation of tumor-related intracellular pathways.
Results: The proteomic analysis revealed that the pre-exposure of glial cells to CM from GBM cells led to the upregulation of several proteins related to inflammatory response, cell adhesion and extracellular structure organization within the secretome of primed glial cells. At the functional levels, CM derived from unprimed glial cells favored an increase in GBM cell migration capacity, while CM from primed glial cells promoted cells viability. These effects on GBM cells were accompanied by activation of particular intracellular cancer-related pathways, mainly the MAPK/ERK pathway, which is a known regulator of cell proliferation.
Conclusions: Together, our results suggest that glial cells can impact on the pathophysiology of GBM tumors, and that the secretome of GBM cells is able to modulate the secretome of neighboring glial cells, in a way that regulates the "go-or-grow" phenotypic switch of GBM cells.Fundação para a Ciência e Tecnologia (IF/00601/2012 to B.M.C.; IF/00111 to A.J.S; SFRH/BD/52287/2013 to A.I.O.; SFRH/BD/81495/2011 to S.I.A.; SFRH/BD/88121/2012 to J.V.C.; projects PTDC/SAU-GMG/113795/2009 to B.M.C.; PTDC/NEU-NMC/0205/2012, PTDC/NEU-SCC/7051/2014, PEst-C/SAU/LA0001/2013–2014 and UID/NEU/04539/2013 to B.M.), Liga Portuguesa Contra o Cancro (B.M.C.), Fundação Calouste Gulbenkian (B.M.C.) and Inter-University Doctoral Programme in Ageing and Chronic Disease (PhDOC; to A.I.O.). Project co-financed by Programa Operacional Regional do Norte (ON.2—O Novo Norte), Quadro de Referência Estratégico Nacional (QREN), Fundo Europeu de Desenvolvimento Regional (FEDER), Programa Operacional Factores de Competitividade (COMPETE), and by The National Mass Spectrometry Network (RNEM) under the contract REDE/1506/REM/2005info:eu-repo/semantics/publishedVersio
A new insight for monitoring ungulates : density surface modelling of roe deer in a Mediterranean habitat
We would like to thank the University of Aveiro (Department of Biology) and FCT/MEC for the financial support to CESAM RU (UID/AMB/50017) through national funds and, where applicable, co-financed by the FEDER, within the PT2020 Partnership Agreement. TAM is partially funded by FCT, Fundação para a Ciência e a Tecnologia, Portugal, through the project UID/MAT/00006/2013.Ungulates are especially difficult to monitor, and population estimates are challenging to obtain; nevertheless, such information is fundamental for effective management. This is particularly important for expanding species such as roe deer (Capreolus capreolus), whose populations dramatically increased in number and geographic distribution over the last decades. In an attempt to follow population trends and assess species ecology, important methodological advances were recently achieved by combining line or point sampling with geographic information systems (GIS). In this study, we combined density surface modelling (DSM) with line transect survey to predict roe deer density in northeastern Portugal. This was based on modelling pellet group counts as a function of environmental factors while taking into account the probability of detecting pellets and conversion factors to relate pellet density to animal density. We estimated a global density of 3.01 animals/100 ha (95 % CI 0.37–3.51) with a 32.82 % CV. Roe deer densities increased with increasing distance to roads as well as with higher percentage of cover areas and decreased with increasing distance to human populations. This recently developed spatial method can be advantageous to predict density over space through the identification of key factors influencing species abundance. Furthermore, surface maps for subset areas will enable to visually depict abundance distribution of wild populations. This will enable the assessment of areas where ungulate impacts should be minimized, allowing an adaptive management through time.PostprintPeer reviewe
Affective state dependence and relative trait stability of perfectionism in sleep disturbances
OBJECTIVE: To evaluate the degree of absolute change, relative stability and state dependence of trait perfectionism in sleep disturbances in a sample of university students. METHOD: Participants completed the Multidimensional Perfectionism Scale and two items concerning sleep difficulties. The mean age at T0 (baseline) was 19.59 years (SD = 1.61, range = 17-25) and 62.5% of the sample were female. RESULTS: Absolute changes in self-oriented and socially-prescribed perfectionism were found. Relative stability was found for all perfectionism dimensions. Prior and concurrent sleep disturbances explained a significant amount of variance in perfectionism. Controlling for the effects of sleep measures, prior selforiented perfectionism and other-oriented perfectionism were the only significant predictors of subsequent self-oriented perfectionism and otheroriented perfectionism, at T1 and T2. Difficulties falling asleep at T1 and socially-prescribed perfectionism at T0 were significant predictors of socially-prescribed perfectionism at T1. CONCLUSION: Despite significant changes in perfectionism mean scores over the follow-up, the correlation analyses demonstrated that participants remained quite stable in regard to their relative levels of perfectionism. As concurrent difficulties initiating sleep also predicted concurrent socially-prescribed perfectionism, this seems to be one dimension of perfectionism with trait-state characteristics.OBJETIVOS: Avaliar o grau de mudança absoluta, de estabilidade relativa e dependência do estado do perfeccionismo nas perturbações de sono numa amostra de estudantes universitários. MÉTODO: Os sujeitos completaram a Escala Multidimensional do Perfeccionismo e dois itens sobre dificuldades em dormir. Os dados foram recolhidos em três momentos de avaliação, separados por um intervalo de um ano acadêmico. A idade média dos sujeitos noT0 era de 19,59 anos (DP = 1,61, variação = 17-25); 62,5% eram mulheres. RESULTADOS: Foram encontradas ao longo do follow-up mudanças absolutas para o Perfeccionismo Autoorientado e para o Perfeccionismo Socialmente Prescrito. Foi encontrada estabilidade relativa para todas as dimensões do perfeccionismo. As dificuldades de sono prévias e concorrentes explicaram significativamente a variância do perfeccionismo. Controlando o efeito das dificuldades em dormir, o Perfeccionismo Autoorientado e o POO prévios foram os únicos preditores significativos de Perfeccionismo Autoorientado e POO subsequente (T1 e T2). As dificuldades em iniciar o sono no T1 e o Perfeccionismo Socialmente Prescrito prévio (T0) revelaram-se preditores significativos dePerfeccionismoSocialmente PrescritonoT1. CONCLUSÃO: Apesar das mudanças significativas nas pontuações médias de perfeccionismo ao longo do follow-up, as análises de correlação demonstraram que os participantes permaneceramrelativamenteestáveisnosseusníveisdeperfeccionismo.Umavezque asdificuldades em iniciar o sono concorrentes serevelaram um preditor significativo de Perfeccionismo Socialmente Prescrito, o Perfeccionismo Socialmente Prescrito é a dimensão do perfeccionismo que possui características traço-estado
One-pot intercalation strategy for the encapsulation of a CO-releasing organometallic molecule in a layered double hydroxide
The photoactivatable CO‐releasing molecule (photoCORM) [Mo(CO)3(CNCH2COOH)3] (ALF795) has been incorporated into a Zn,Al layered double hydroxide (LDH) host by a coprecipitation synthesis strategy. Powder X‐ray diffraction (PXRD) of the resultant material Zn,Al‐ALF795 showed that the ALF795 guest molecules assembled into a monolayer to give a basal spacing of 16.0 Å. FTIR and 13C{1H} CP MAS NMR spectroscopy confirmed that the molecular structure of the tricarbonyl complex was retained upon intercalation. Scanning electron microscopy (SEM), energy‐dispersive X‐ray spectroscopy (EDS) and elemental analyses confirmed the phase‐purity of Zn,Al‐ALF795. The myoglobin assay was used to demonstrate that intercalated ALF795 retains the photoactive behavior of the free CORM, with a substantial fraction (42 %) of the high CO payload (2.46 mmol g–1) being released after exposure to UV light for 3 h under simulated physiological conditions. In addition, gas chromatography was used to track sequential light‐ and H2O2‐triggered decarbonylation of free and intercalated ALF795. In biological buffer solution (HEPES), less than 2 % Mo leaching from Zn,Al‐ALF795 took place after 5 h, showing the strong capacity of the LDH host to retain the unaltered complex and decarbonylation fragments.publishe
Ruthenium-cyclopentadienyl bipyridine-biotin based compounds: Synthesis and biological effect
Prospective anticancer metallodrugs should consider target-specific components in their design in order to overcome the limitations of the current chemotherapeutics. The inclusion of vitamins, which receptors are overexpressed in many cancer cell lines, has proven to be a valid strategy. Therefore, in this paper we report the synthesis and characterization of a set of new compounds [Ru(eta(5)-C5H5)(P(C6H4R)(3))(4,4'-R'-2,2'-bpy)](+) (R = F and R' = H, 3; R = F and R' = biotin, 4; R = OCH3 and R' = H, 5; R = OCH3 and R' = biotin, 6), inspired by the exceptional good results recently obtained for the analogue bearing a triphenylphosphane ligand. The precursors for these syntheses were also described following modified literature procedures, [Ru(eta(5)-C5H3)(P(C6H4R)(3))(2)Cl], where R is -F (1) or -OCH3 (2). The structure of all compounds is fully supported by spectroscopic and analytical techniques and by X-ray diffraction studies for compounds 2, 3, and 5. All cationic compounds are cytotoxic in the two breast cancer cell lines tested, MCF7 and MDA-MB-231, and much better than cisplatin under the same experimental conditions. The cytotoxicity of the biotinylated compounds seems to be related with the Ru uptake by the cells expressing biotin receptors, indicating a potential mediated uptake. Indeed, a biotin-avidin study confirmed that the attachment of biotin to the organometallic fragment still allows biotin recognition by the protein. Therefore, the biotinylated compounds might be potent anticancer drugs as they show cytotoxic effect in breast cancer cells at low dose dependent on the compounds' uptake, induce cell death by apoptosis and inhibit the colony formation of cancer cells causing also less severe side effects in zebrafish.This work was financed by the Portuguese Foundation for Science and Technology (Fundacao para a Crencia e Tecnologia, FCT) within the scope of Projects UID/QUI/00100/2019 and PTDC/QUI-QIN/28662/2017. This work was supported by the strategic program UID/BIA/04050/2013 (POCI-01-0145-FEDER-007569) funded by national funds through the FCT I.P. and by the ERDF through the COMPETE2020 -Programa Operacional Competitividade e Intemacionalizacao (POCI). A.V. acknowledges the Investigator FCT2013 Initiative for the Project IF/01302/2013 and CEEC-IND/01974/2017 (acknowledging FCT, as well as POPH and FSE, the European Social Fund). L.C.-R, A.R.B. and A.P. thank FCT for their Ph.D. Grants (SFRH/BD/100515/2014, SFRH/BD/139271/2018, and SFRH/BD/139412/2018, respectively). L.C.-R also acknowledges Fulbright Research Grant 2017/2018 with the support of FCT. Brittany Karas acknowledges NJAES-RutgersNJ01201 and NIEHS Training Grant T32-ES 007148 and B.T.B. and C.D. acknowledge NIH-NIEHS P30 ES005022. K.R.C. acknowledges NJAES Project 01202 (W2045) and NIH ES005022
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