Blood flow of bubbles moving in microchannels with bifurcations

The gas embolism is a well-known phenomenon. Previous studies have been performed to understand the formation, the behavior and the influence of air bubbles in microcirculation. This study aims to investigate the flow of bubbles in a microchannel network with bifurcations. For that purpose, a microchannel network was fabricated by soft lithography. The working fluids used were composed by sheep red blood cells (RBCs) suspended in dextran 40 and two different hematocrits were studied, 5% and 10%. The in vitro blood flow was analyzed for a flow rate of lO ~-tllmin, by using an inverted microscope and a high-speed camera. It was possible to visualize the formation of the bubbles and their behavior along the network. The results show that the passage of air bubbles influences the cells local concentration, since a higher concentration of cells was seen upstream to the bubble and lower concentrations downstream to the bubble.This work was supported by Fundação para a Ciência e a Tecnologia (FCT), Portugal, under the strategic grants UID/EMS/04077/2019, UID/EEA/04436/2019 and UID/EMS/00532/2019. The authors are also grateful for the partial funding of FCT through the projects POCI-01-0145-FEDER-016861 (ref: PTDC/QEQ-FIT/4287/2014), NORTE-01-0145- FEDER-029394, NORTE-01-0145-FEDER-030171, funded by COMPETE2020, NOR1E2020, PORTUGAL2020, and FEDER. D. Bento acknowledges the PhD scholarship SFRH/BD/911921 2012 granted by FCT.info:eu-repo/semantics/publishedVersio

Evolution of squeezed states under the Fock-Darwin Hamiltonian

We develop a complete analytical description of the time evolution of squeezed states of a charged particle under the Fock-Darwin Hamiltonian and a time-dependent electric field. This result generalises a relation obtained by Infeld and Pleba\'nski for states of the one-dimensional harmonic oscillator. We relate the evolution of a state-vector subjected to squeezing to that of state which is not subjected to squeezing and for which the time-evolution under the simple harmonic oscillator dynamics is known (e.g. an eigenstate of the Hamiltonian). A corresponding relation is also established for the Wigner functions of the states, in view of their utility in the analysis of cold-ion experiments. In an appendix, we compute the response functions of the FD Hamiltonian to an external electric field, using the same techniques as in the main text

Arbuscular mycorrhizal fungi inoculation reduced the growth of pre-rooted olive cuttings in a greenhouse

The effect of commercial mycorrhizal fungi on pre-rooted olive cuttings was assessed. The study consisted of two experiments, the first arranged as a factorial design with three cultivars (Cobrançosa, Madural, and Verdeal Transmontana) and three soil treatments (commercial mycorrhizal fungi, zeolites, and control) and the second as a completely randomized design with three treatments (commercial mycorrhizal fungi, sterilized soil, and control). Cobrançosa grew better than the other cultivars, showing good rooting and initial growth features. Mycorrhizal plants showed reduced growth in comparison to those of the untreated control. This result was explained by competition for photosynthates between plant growth and the expansion of fungi hyphae. Cuttings of reduced leaf area and a twin-wall polycarbonate cover of the greenhouse, somewhat opaque to photosynthetic active radiation, may also have contributed to limit the maximum photosynthetic rate and delay the growth of the inoculated plants. Accordingly, in the mycorrhizal pots, the soil organic carbon (C) increased, probably due to the presence of fungi hyphae in soil samples. Zeolites reduced plant dry matter (DM) yield and tissue phosphorus (P) concentration compared to the control, while increasing the availability in the soil of the cations present in their initial composition. Soil sterilization seems to have reduced soil P bioavailability by inactivating soil enzymes. This study showed that the inoculation with mycorrhizal fungi of pre-rooted cuttings can delay their initial growth. Although these plants may be better prepared to grow in the field, in the short term, their lower development can be a problem for the nurseryman.This research was funded by the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO (UIDB/00690/2020) and CITAB (UIDB/04033/2020). The research was integrated in the activities of the operational group “Novas práticas em olivais de sequeiro: estratégias de mitigação e adaptação às alterações climáticas”, funded by PT2020 and EAFRD (European Agricultural Fund for Rural Development).info:eu-repo/semantics/publishedVersio

Renormalisation scheme for vector fields on T2 with a diophantine frequency

We construct a rigorous renormalisation scheme for analytic vector fields on the 2-torus of Poincare type. We show that iterating this procedure there is convergence to a limit set with a ``Gauss map'' dynamics on it, related to the continued fraction expansion of the slope of the frequencies. This is valid for diophantine frequency vectors.Comment: final versio

Tendão cricoesofágico no furão (Mustela putorius furo)

The AA. examined the original band of the esophageal striated musculature in ferret (MUSTELA PUTORIUS FURO). They recognized it as being the cricoesophageal tendon, by its anatomical and histologic disposition, similar to the men’s dog’s and cat’s.O artigo apresenta resumo em inglês

Sustainable woody biomass production systems: a novel solution for energy, agriculture and the environment in Portugal

Bioenergy is a major current issue within the agriculture and energy sectors and the society in general. The environmental and social concerns raised by first generation biofuel crops increased the interest on woody biomass. Biomass production for direct conversion to heat and/or electricity is common in northern European countries, the USA, and, more recently, southern Europe, mainly based on short rotation woody crops (SRWC). These crops are renewable sources of energy, CO2 neutral, able to preserve biodiversity and water, and to contribute to socio-economic development. In Portugal, there is an increasing demand of renewable and sustainable sources of energy. Portugal also presents conditions to expand biomass production and use for energy, namely through SRWCs. There is, however, a lack of experience in this field. With the purpose of studying short rotation woody crops dedicated to energy production, we have launched in Bragança, Portugal, a research project aiming to develop technology for the sustainable production, processing, and use of woody biomass for energy. The goal is to analyse environmental and socio-economic aspects of these crops considering carbon cycle, conservation of water, soils, and biodiversity, as well as creation of wealth locally. It also aims to evaluate the potential of northeastern Portugal for biomass production and carbon sequestration. In this presentation we address the rational behind the project, the methodologies followed, and the results obtained during the first year of the study. We also present our perspectives on the role of woody biomass production at several scales and for several scenarios.Fundação para a Ciência e Tecnologia. (PTDC/AGR‐CFL/64500/2006

Contributo para o conhecimento da biodiversidade marinha da ilha das Flores

XIII Expedição Científica do Departamento de Biologia - Flores e Corvo 2007.No âmbito da XIII Expedição Científica Flores e Corvo/2007, organizada pelo Departamento de Biologia da Universidade dos Açores, efectuaram-se várias observações e recolhas de organismos marinhos, utilizando 3 metodologias: mergulho (bentos), arrasto (plâncton) e prospecção no intertidal

Preschool literacy and reading performance in primary school

A literacia pré-escolar tem recebido uma crescente atenção. Neste estudo, participaram 70 crianças que iniciaram o 1.º ano de escolaridade no ano letivo 2009/10 e que, na educação pré-escolar, frequentaram três instituições com abordagens diferenciadas de leitura e de escrita. O estudo inclui quatro medidas repetidas no tempo nas áreas da fonologia, reconhecimento de letras, palavras e velocidade de leitura. Os resultados sugerem que a abordagem específica à leitura na educação pré-escolar condiciona o desempenho da leitura na instrução primária. Contudo, essa influência parece ser atenuada com o tempo. Por outro lado, verificou-se que sujeitos que receberam instrução direta de leitura em idade pré-escolar (mas não treino fonológico) obtêm resultados significativamente superiores em tarefas fonológicas aos de sujeitos que receberam treino fonológico prolongado (mas não de leitura).The debate regarding kindergarten literacy has received increasing attention and social visibility. In this study, participants are 70 children who attended first grade in 2009/2010. Participants attended three kindergartens with unique approaches to reading. A four wave repeated measure design was conducted to investigate the growth of the children in phonological awareness, letter recognition, word recognition, and reading speed. Results suggest that the approach towards reading and writing in kindergarten affects children's performance in grades 1 and 2 of elementary school. This influence, however, seems to fade over time. Moreover, results show that children who received formal reading instruction in kindergarten, perform significantly better in phonological tasks than children who received direct and extended phonological instruction.(undefined)info:eu-repo/semantics/publishedVersio

The long-term evolution of the Douro River as evidenced by strath terrace staircases located at NE Portugal (western Iberia)

In western Iberia, mechanisms that explain the transition from endorheic to exorheic continental-scale drainage reorganisation are foreland basin overspill, headwards erosion and capture by an Atlantic river, or a combination of both. To explore these controls we have investigated the Portuguese sector of the Douro River, the site of drainage re-organsation. The Douro River routes downstream through weak sedimentary infill of the Douro Cenozoic Basin (Spain), after which the river cuts down through granitic and metamorphic rocks cut by active fault zones (NE Portugal), before reaching the Atlantic coast. We investigated the drainage reorganisation using an integrated remote sensing, field survey and geochronological approach applied to Pliocene-Quaternary fluvial sediments and landforms. The older drainage record is documented by a series of high and intermediate landform levels comprising 1) a high level (1000-600 m) faulted regional fluvial erosion surface, the North Iberian Meseta Planation Surface (NIMPS); 2) an inset level (650-600 m altitude) comprising a broad fluvial surface formed onto a large ENE-WSW depression that overlies resistant ProterozoicandPaleozoic bedrock and 3) an inset (500450m) fluvial surface. The younger drainage record comprises an entrenched fluvial strath terrace sequence of up to 9 levels (T9 = oldest positioned at 246-242 m above the modern river base (a.r.b); T1 = youngest positioned at 17-13 m a.r.b.). Levels T1 and T3 display fault offsets where the cross active NNE-SSW fault zones. The three lowest terrace levels (T1-T3) were dated using optically stimulated luminescence (OSL) techniques using Quartz-OSL and post infra-red stimulated luminescence (pIRIR). Results ranged from 39-12ka (T1), 57ka (T2) and >360ka (minimum) (T3). Fluvial incision rates of the younger (terrace) drainage record were quantified and temporally exptrapolated to model the ages of the high to intermediate elevation levels of the early drainage record. Integration of incision data with fault zone derived crustal uplift values informs on the timing of the endorheic to exhoreic drainage reorganization. We interpret the NIMPS to be part of the endorehic Douro Cenozoic Basin drainage divide erosion. The inset wide fluvial surface at 650-600 m altitude represents the overspill level in the area of the Mesão Frio ridges (drainage divide with the Atlantic drainage). Development of the exhoreic ancestral Douro valley is documented in the 500-450 m fluvial surface with our age and uplift modelling suggesting this became established during the upper Pleistocene (3.6 Ma) through to the Early Pleistocene (1.8 Ma). The entrenched river terrace sequence spans the Pleistocene, developing via spatial and temporal variations in rock strength, uplift and cyclic cool climate variability as the river adjusts to the Atlantic base level

Photocatalytic removal of benzene over Ti3C2Tx MXene and TiO2–MXene composite materials under solar and NIR irradiation

MXenes, a family of two-dimensional (2D) transition metal carbides, nitrides and carbonitrides based on earth-abundant constituents, are prospective candidates for energy conversion applications, including photocatalysis. While the activity of individual MXenes towards various photocatalytic processes is still debatable, these materials were proved to be excellent co-catalysts, accelerating the charge separation and suppressing the exciton recombination. Titanium-containing MXenes are well compatible with the classical TiO2 photocatalyst. The TiO2 component can be directly grown on MXene sheets by in situ oxidation, representing a mainstream processing approach for such composites. In this study, an essentially different approach has been implemented: a series of TiO2-MXene composite materials with controlled composition and both reference end members were prepared, involving two different strategies for mixing sol-gel-derived TiO2 nanopowder with the Ti3C2Tx component, which was obtained by HF etching of self-propagating high-temperature synthesis products containing modified MAX phase Ti3C2Alz (z > 1) with nominal aluminium excess. The prospects of such composites for the degradation of organic pollutants under simulated solar light, using benzene as a model system, were demonstrated and analysed in combination with their structural, microstructural and optical properties. A notable photocatalytic activity of bare MXene under near infrared light was discovered, suggesting further prospects for light-to-energy harvesting spanning from UV-A to NIR and applications in biomedical imaging and sensors.publishe