794 research outputs found

    Semiclassical Propagation of Wavepackets with Real and Complex Trajectories

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    We consider a semiclassical approximation for the time evolution of an originally gaussian wave packet in terms of complex trajectories. We also derive additional approximations replacing the complex trajectories by real ones. These yield three different semiclassical formulae involving different real trajectories. One of these formulae is Heller's thawed gaussian approximation. The other approximations are non-gaussian and may involve several trajectories determined by mixed initial-final conditions. These different formulae are tested for the cases of scattering by a hard wall, scattering by an attractive gaussian potential, and bound motion in a quartic oscillator. The formula with complex trajectories gives good results in all cases. The non-gaussian approximations with real trajectories work well in some cases, whereas the thawed gaussian works only in very simple situations.Comment: revised text, 24 pages, 6 figure

    Synonymy of Orthomus susanae Serrano & Borges, 2009 with Orthomus annae (Donabauer, 2008) (Coleoptera: Carabidae)

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    Copyright © 2012 Magnolia Press.[...]. Some time after the publication of their paper in Zootaxa, the authors found out that another Madeiran Orthomus species had been described one month earlier (Donabauer 2008). Taking in consideration the morphological characteristics of the specimens described in both papers and the coincidence of the type localities no doubts remained regarding the synonymy between the two species

    Colonisation resistance in the sand fly gut:Leishmania protects Lutzomyia longipalpis from bacterial infection

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    BACKGROUND: Phlebotomine sand flies transmit the haemoflagellate Leishmania, the causative agent of human leishmaniasis. The Leishmania promastigotes are confined to the gut lumen and are exposed to the gut microbiota within female sand flies. Here we study the colonisation resistance of yeast and bacteria in preventing the establishment of a Leishmania population in sand flies and the ability of Leishmania to provide colonisation resistance towards the insect bacterial pathogen Serratia marcescens that is also pathogenic towards Leishmania. METHODS: We isolated microorganisms from wild-caught and laboratory-reared female Lutzomyia longipalpis, identified as Pseudozyma sp. Asaia sp. and Ochrobactrum intermedium. We fed the females with a sugar meal containing the microorganisms and then subsequently fed them with a bloodmeal containing Leishmania mexicana and recorded the development of the Leishmania population. Further experiments examined the effect of first colonising the sand fly gut with L. mexicana followed by feeding with, Serratia marcescens, an insect bacterial pathogen. The mortality of the flies due to S. marcescens was recorded in the presence and absence of Leishmania. RESULTS: There was a reduction in the number of flies harbouring a Leishmania population that had been pre-fed with Pseudozyma sp. and Asaia sp. or O. intermedium. Experiments in which L. mexicana colonised the sand fly gut prior to being fed an insect bacterial pathogen, Serratia marcescens, showed that the survival of flies with a Leishmania infection was significantly higher compared to flies without Leishmania infection. CONCLUSIONS: The yeast and bacterial colonisation experiments show that the presence of sand fly gut microorganisms reduce the potential for Leishmania to establish within the sand fly vector. Sand flies infected with Leishmania were able to survive an attack by the bacterial pathogen that would have killed the insect and we concluded that Leishmania may benefit its insect host whilst increasing the potential to establish itself in the sand fly vector. We suggest that the increased ability of the sand fly to withstand a bacterial entomopathogen, due to the presence of the Leishmania, may provide an evolutionary pressure for the maintenance of the Leishmania-vector association

    Caracterização física e mecânica de argamassas com incorporação de resíduos industriais

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    A indústria da fundição produz milhões de toneladas de resíduos descartados em todo o mundo. Atualmente, o aumento dos custos e os problemas ambientais relacionados com a deposição de resíduos em aterros é um enorme problema. Assim, muitos estudos têm-se concentrado nas areias de fundição, contudo outros resíduos são gerados durante o processo de fundição e não se conhecem soluções de reutilização, tais como as ceras parafínicas e as cascas de moldes cerâmicos. O objetivo principal deste estudo foi a incorporação de ceras parafínicas e cascas de moldes cerâmicos em argamassas de cimento, avaliando a influência de diferentes teores de parafina nas propriedades físicas e mecânicas das argamassas. Os resultados obtidos mostraram uma diminuição da trabalhabilidade, absorção de água, resistência à flexão e à compressão das argamassas. No entanto, as argamassas apresentaram um comportamento físico e mecânico satisfatório, evidenciando uma possível aplicação prática.The foundry industry produces millions of tonnes of discarded waste worldwide. Currently, increasing costs and environmental problems related to landfilling waste is a huge problem. Thus, many studies have focused on foundry sands, however other wastes are generated during the casting process and no reuse solutions are known, such as paraffin waxes and ceramic mold shells. The main objective of this study was the incorporation of paraffin waxes and ceramic mold shells in cement mortars, evaluating the influence of different paraffin wax contents in the mortars physical and mechanical properties. The obtained results showed a decrease in the workability, water absorption, flexural and compressive strengths of the mortars. However, the mortars presented a satisfactory physical and mechanical behavior, evidencing a possible practical application.Este trabalho foi apoiado pela FCT/MCTES através de fundos nacionais (PIDDAC) sob a referência UIDB/04047/2020 da Unidade de I&D do Centro de Território, Ambiente e Construção (CTAC)

    Treatment of facial aging with calcium hydroxyapatite - filling and lifting concept

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    The face is organized in five different layers (skin, muscles, supportive ligaments, fat pads and bones), which are continuous and interconnected with each other from the scalp to the neck. As a result of aging, changes occur in all its tissues and structures, triggering a cascade of effects in the adjacent areas. Actually, the more it is known about the loss of volume, the better it is to establish the target spots for volume replacement, with consequent more natural- and harmonious-looking outcomes. However, the skin is the outer envelope of the face, which, in the natural process of aging, has a lower capacity to completely accommodate any underlying volume loss or displacement. The result is the formation of creases and folds due to skin sagging. To describe the effects of the injection of calcium hydroxyapatite (CaHA) targeting two objectives at the same time: the restoration of volume loss to compensate the changes in the tridimensional structure and the improvement in skin texture caused by the stimulus to collagen synthesis, thus reducing the sagging of soft tissues envelope. Owing to the mechanism of action of CaHA, its application can be done in two differentiated and little invasive ways so that these objectives can be reached simultaneously. This technique can provide safe, natural and long-lasting rejuvenating effects. DOI: http://dx.doi.org/10.5281/zenodo.356983

    Brain Pathways Involved in the Modulatory Effects of Noradrenaline in Lateral Septal Area on Cardiovascular Responses

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    We have previously reported that stimulation of alpha-1 adrenoceptors by noradrenaline (NA) injected into the lateral septal area (LSA) of anaesthetized rats causes pressor and bradycardic responses that are mediated by acute vasopressin release into the circulation through activation of the paraventricular nucleus (PVN). Although the PVN is the final structure of this pathway, the LSA has no direct connections with the PVN, suggesting that other structures may connect these areas. To address this issue, the present study employed c-Fos immunohistochemistry to investigate changes caused by NA microinjection into the LSA in neuronal activation in brain structures related to systemic vasopressin release. NA microinjected in the LSA caused pressor and bradycardic responses, which were blocked by intraseptal administration of alpha-1 adrenoceptor antagonist (WB4101, 10 nmol/200 nL) or systemic V-1 receptor antagonist (dTyr(CH2)5(Me)AVP, 50 mu g/kg). NA also increased c-Fos immunoreactivity in the prelimbic cortex (PL), infralimbic cortex (IL), dorsomedial periaqueductal gray (dmPAG), bed nucleus of the stria terminalis (BNST), PVN, and medial amygdala (MeA). No differences in the diagonal band of Broca, cingulate cortex, and dorsolateral periaqueductal gray (dlPAG) were found. Systemic administration of the vasopressin receptor antagonist dTyr AVP (CH2)5(Me) did not change the increase in c-Fos expression induced by intra-septal NA. This latter effect, however, was prevented by local injection of the alpha-1 adrenoceptor antagonist WB4101. These results suggest that areas such as the PL, IL, dmPAG, BNST, MeA, and PVN could be part of a circuit responsible for vasopressin release after activation of alpha-1 adrenoceptors in the LSA.CAPES [PNPD0176087]CNPqFAPES

    Spatial Factors Play a Major Role as Determinants of Endemic Ground Beetle Beta Diversity of Madeira Island Laurisilva

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    The development in recent years of new beta diversity analytical approaches highlighted valuable information on the different processes structuring ecological communities. A crucial development for the understanding of beta diversity patterns was also its differentiation in two components: species turnover and richness differences. In this study, we evaluate beta diversity patterns of ground beetles from 26 sites in Madeira Island distributed throughout Laurisilva – a relict forest restricted to the Macaronesian archipelagos. We assess how the two components of ground beetle beta diversity (βrepl – species turnover and βrich - species richness differences) relate with differences in climate, geography, landscape composition matrix, woody plant species richness and soil characteristics and the relative importance of the effects of these variables at different spatial scales. We sampled 1025 specimens from 31 species, most of which are endemic to Madeira Island. A spatially explicit analysis was used to evaluate the contribution of pure environmental, pure spatial and environmental spatially structured effects on variation in ground beetle species richness and composition. Variation partitioning showed that 31.9% of species turnover (βrepl) and 40.7% of species richness variation (βrich) could be explained by the environmental and spatial variables. However, different environmental variables controlled the two types of beta diversity: βrepl was influenced by climate, disturbance and soil organic matter content whilst βrich was controlled by altitude and slope. Furthermore, spatial variables, represented through Moran’s eigenvector maps, played a significant role in explaining both βrepl and βrich, suggesting that both dispersal ability and Madeira Island complex orography are crucial for the understanding of beta diversity patterns in this group of beetles.Peer reviewe

    Ranking protected areas in the Azores using standardised sampling of soil epigean arthropods

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    Copyright © Springer 2005.Nineteen areas in seven of the nine Azorean islands were evaluated for species diversity and rarity based on soil epigean arthropods. Fifteen out of the 19 study areas are managed as Natural Forest Reserves and the remaining four were included due to their importance as indigenous forest cover. Four of the 19 areas are not included in the European Conservation network, NATURA 2000. Two sampling replicates were run per study area, and a total of 191 species were collected; 43 of those species (23%) are endemic to the archipelago and 12 have yet to be described. To produce an unbiased multiple-criteria index (importance value for conservation, IV-C) incorporating diversity and rarity based indices, an iterative partial multiple regression analysis was performed. In addition, an irreplaceability index and the complementarity method (using both optimisation and heuristic methods) were used for priority-reserves analyses. It was concluded that at least one well-managed reserve per island is absolutely necessary to have a good fraction of the endemic arthropods preserved. We found that for presence/absence data the suboptimal complementarity algorithm provides solutions as good as the optimal algorithm. For abundance data, optimal solutions indicate that most reserves are needed if we want that at least 50% of endemic arthropod populations are represented in a minimum set of reserves. Consistently, two of the four areas not included in the NATURA 2000 framework were considered of high priority, indicating that vascular plants and bird species used to determine NATURA 2000 sites are not good surrogates of arthropod diversity in the Azores. The most irreplaceable reserves are those located in older islands, which indicates that geological history plays an important role in explaining faunal diversity of arthropods in the Azores. Based both on the uniqueness of species composition and high species richness, conservation efforts should be focused on the unmanaged Pico Alto region in the archipelago’s oldest island, Santa Maria

    Patient-physician discordance in assessment of adherence to inhaled controller medication: a cross-sectional analysis of two cohorts

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    We aimed to compare patient's and physician's ratings of inhaled medication adherence and to identify predictors of patient-physician discordance.(SFRH/BPD/115169/2016) funded by Fundação para a Ciência e Tecnologia (FCT); ERDF (European Regional Development Fund) through the operations: POCI-01-0145-FEDER-029130 ('mINSPIRERS—mHealth to measure and improve adherence to medication in chronic obstructive respiratory diseases—generalisation and evaluation of gamification, peer support and advanced image processing technologies') cofunded by the COMPETE2020 (Programa Operacional Competitividade e Internacionalização), Portugal 2020 and by Portuguese Funds through FCT (Fundação para a Ciência e a Tecnologia).info:eu-repo/semantics/publishedVersio

    A comparative analysis of terrestrial arthropod assemblages from a relict forest unveils historical extinctions and colonization differences between two oceanic islands

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    During the last few centuries oceanic island biodiversity has been drastically modified by human-mediated activities. These changes have led to the increased homogenization of island biota and to a high number of extinctions lending support to the recognition of oceanic islands as major threatspots worldwide. Here, we investigate the impact of habitat changes on the spider and ground beetle assemblages of the native forests of Madeira (Madeira archipelago) and Terceira (Azores archipelago) and evaluate its effects on the relative contribution of rare endemics and introduced species to island biodiversity patterns. We found that the native laurel forest of Madeira supported higher species richness of spiders and ground beetles compared with Terceira, including a much larger proportion of indigenous species, particularly endemics. In Terceira, introduced species are well-represented in both terrestrial arthropod taxa and seem to thrive in native forests as shown by the analysis of species abundance distributions (SAD) and occupancy frequency distributions (OFD). Low abundance range-restricted species in Terceira are mostly introduced species dispersing from neighbouring man-made habitats while in Madeira a large number of true rare endemic species can still be found in the native laurel forest. Further, our comparative analysis shows striking differences in species richness and composition that are due to the geographical and geological particularities of the two islands, but also seem to reflect the differences in the severity of human-mediated impacts between them. The high proportion of introduced species, the virtual absence of rare native species and the finding that the SADs and OFDs of introduced species match the pattern of native species in Terceira suggest the role of man as an important driver of species diversity in oceanic islands and add evidence for an extensive and severe human-induced species loss in the native forests of Terceira.Peer reviewe
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