Scalar Casimir Effect on a D-dimensional Einstein Static Universe

We compute the renormalised energy momentum tensor of a free scalar field coupled to gravity on an (n+1)-dimensional Einstein Static Universe (ESU), RxS^n, with arbitrary low energy effective operators (up to mass dimension n+1). A generic class of regulators is used, together with the Abel-Plana formula, leading to a manifestly regulator independent result. The general structure of the divergences is analysed to show that all the gravitational couplings (not just the cosmological constant) are renormalised for an arbitrary regulator. Various commonly used methods (damping function, point-splitting, momentum cut-off and zeta function) are shown to, effectively, belong to the given class. The final results depend strongly on the parity of n. A detailed analytical and numerical analysis is performed for the behaviours of the renormalised energy density and a quantity `sigma' which determines if the strong energy condition holds for the `quantum fluid'. We briefly discuss the quantum fluid back-reaction problem, via the higher dimensional Friedmann and Raychaudhuri equations, observe that equilibrium radii exist and unveil the possibility of a `Casimir stabilisation of Einstein Static Universes'.Comment: 37 pages, 15 figures, v2: minor changes in sections 1, 2.5, 3 and 4; version published in CQ

Evaluation of Road Signs conformity for improving road safety in urban Areas: a Case Study in Guimarães, Portugal

A segurança rodoviária depende da existência de uma rede de sinalética apropriada e de uma correta manutenção dos sinais ao longo do tempo. Os sinais verticais de trânsito, para serem efetivamente funcionais, devem permanecer adequadamente visíveis e percetíveis. Neste artigo apresenta-se uma metodologia para avaliar o nível de conformidade dos sinais, procurando identificar eventuais deficiências funcionais. A metodologia baseia-se numa análise multicritério, onde são considerados dois critérios e oito subcritérios relacionados com as características físicas e operacionais dos sinais. A visibilidade dos sinais foi avaliada através de uma análise em SIG, considerando as distâncias de travagem e de paragem. O nível de intervenção obtido é constituído por quatro níveis, em função da necessidade e da urgência em recuperar a função dos sinais. A metodologia foi aplicada na cidade de Guimarães, Portugal. Os resultados comprovam a funcionalidade da metodologia e revelam que mais de metade dos sinais analisados não estão totalmente em conformidade com as normas, muito por culpa da estrutura urbana compacta e da presença de vegetação nas ruas. Uma vez que, para vários sinais, as distâncias de travagem e de paragem não são adequadas, pode-se concluir que os utilizadores destas ruas estão expostos a riscos que ameaçam a sua segurança.Road safety depends on the existence of an adequate network of signs and an effective management for proper conservation. Vertical traffic signs will only be effectively functional if they still provide adequate visibility and legibility. This paper presents a methodology to evaluate the level of conformity of traffic signs, in order to identify where to improve their functionality. The methodology is based on a multicriteria analysis, using two criteria and eight subcriteria that are related with signs physical and operational attributes. Their visibility was evaluated through a spatial analysis in a geographical information system, taking into account the braking and stopping distances. The intervention level is defined by four levels related with the necessity and urgency in restoring signs functionality. This methodology was applied in the city of Guimarães, Portugal. The results showed the usefulness of the methodology and revealed that more than half of the analyzed signs not fully complied with the norms, mainly due to the compactness of the urban structure e the presence of vegetation in streets. Since the braking and stopping distances of many signs are not adequate, it can be concluded that road users are exposed to risks and their safety can be threated.info:eu-repo/semantics/publishedVersio

Galactodendritic Phthalocyanine Targets Carbohydrate- Binding Proteins Enhancing Photodynamic Therapy

Photosensitizers (PSs) are of crucial importance in the effectiveness of photodynamic therapy (PDT) for cancer. Due to their high reactive oxygen species production and strong absorption in the wavelength range between 650 and 850 nm, where tissue light penetration is rather high, phthalocyanines (Pcs) have been studied as PSs of excellence. In this work, we report the evaluation of a phthalocyanine surrounded by a carbohydrate shell of sixteen galactose units distributed in a dendritic manner (PcGal16) as a new and efficient third generation PSs for PDT against two bladder cancer cell lines, HT-1376 and UMUC- 3. Here, we define the role of galacto-dendritic units in promoting the uptake of a Pc through interaction with GLUT1 and galectin-1. The photoactivation of PcGal16 induces cell death by generating oxidative stress. Although PDT with PcGal16 induces an increase on the activity of antioxidant enzymes immediately after PDT, bladder cancer cells are unable to recover from the PDT-induced damage effects for at least 72 h after treatment. PcGal16 co-localization with galectin-1 and GLUT1 and/or generation of oxidative stress after PcGal16 photoactivation induces changes in the levels of these proteins. Knockdown of galectin-1 and GLUT1, via small interfering RNA (siRNA), in bladder cancer cells decreases intracellular uptake and phototoxicity of PcGal16. The results reported herein show PcGal16 as a promising therapeutic agent for the treatment of bladder cancer, which is the fifth most common type of cancer with the highest rate of recurrence of any cancer

The secretome of stem cells isolated from the adipose tissue and wharton jelly acts differently on central nervous system derived cell populations

Introduction: It is hypothesized that administration of stromal/stem cells isolated from the adipose tissue (ASCs) and umbilical cord (HUCPVCs) can ameliorate the inured CNS. However it is still not clear whether they have similar or opposite effects on primary cultures of neuronal populations. The objective of the present work was to determine if ASCs and HUCPVCs preferentially act, or not, on specific cell populations within the CNS. Methods: Primary cultures of hippocampal neurons were exposed to ASCs and HUCPVCs conditioned media (CM) (obtained 24, 48, 72 and 96 hours after 3 days of culture) for 1 week. Results: Cell viability experiments (MTS test) revealed that CM obtained from both cell populations at all time points did not cause any deleterious effects on neuronal cells. In fact, it was determined that whenever the ASCs CM were supplemented with bFGF and B27, there was a significant increase on the metabolic viability and neuronal cell density of the cultures. On the other hand in the absence of CM supplementation, it was the HUCPVCs secretome that had the highest impact on the metabolic viability and cell density. In an attempt to unveil which factors could be involved in the observed effects, a screening for the presence of basic fibroblast growth factor (bFGF), nerve growth factor (NGF), stem cell factor (SCF), hepatocyte growth factors (HGF) and vascular endothelial growth factor (VEGF) in the CM was performed. Results revealed the presence of all these factors in ASCs CM, except bFGF; in contrast, in HUCPVCs CM it was only possible to detect robust NGF expression. Conclusions: Overall the results herein confirm important differences on the secretome of ASCs and HUCPVCs, which leads to distinct effects on the metabolic viability and neuronal cell densities in primary cultures of hippocampal neurons; however, the factor(s) that promote the stronger effect of the HUCPVCs CM in neuronal survival is (are) still to be identified.Pennington Biomedical Research FoundationFoundation Calouste de Gulbenkian - The Gulbenkian Programme to Support Research in the Life Sciences and Ciência 2007 ProgramFundação para a Ciência e a Tecnologia (FCT

Avaliação da visibilidade de sinais de trânsito com base numa análise multicritério implementada num SIG. Uma aplicação no centro de Guimarães, Portugal

Publicado em "Anais do 7º Congresso Luso-Brasileiro para o Planejamento Urbano, Regional, Integrado e Sustentável"A visibilidade dos sinais de trânsito é fundamental para regular o tráfego rodoviário, auxiliar os condutores e garantir a segurança dos utilizadores das vias. Neste artigo apresenta-se uma metodologia para avaliar a visibilidade dos sinais verticais de trânsito. Com base numa análise multicritério, atribuiram-se pesos a três parâmetros que condicionam a visibilidade dos sinais: a dimensão do sinal, a dimensão do poste e a visibilidade do sinal. A análise da visibilidade foi realizada através do geoprocessamento num SIG a partir da rasterização do terreno. Com a aplicação da análise multicritério obteve-se uma escala de prioridades de intervenção associada à visibilidade dos sinais. Esta metodologia foi aplicada a um conjunto de sinais na cidade de Guimarães, Portugal. Os resultados comprovam a funcionalidade da metodologia e revelam que os sinais na cidade de Guimarães têm problemas de visibilidade resultantes da estrutura urbana compacta e da presença de vegetação nas ruas

Sustainable smart tags with two‐step verification for anticounterfeiting triggered by the photothermal response of upconverting nanoparticles

No abstract available.This work was developed within the scope of the projects CICECO-Aveiro Institute of Materials (UIDB/50011/2020 and UIDP/50011/2020) and Shape of Water (PTDC/NAN-PRO/3881/2020) financed by Portuguese funds through the FCT/MEC and when appropriate cofinanced by FEDER under the PT2020 Partnership Agreement. F.E.M. acknowledges the funding received from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement no. 823941. The support of the European Union’s Horizon 2020 FET Open program under grant agreement no. 801305 (NanoTBTech) is also acknowledged. R.R.S. acknowledges the financial support from the Brazilian agency FAPESP (process no. 16/06612-6).publishe

Integrating of the seahorse Hippocampus reidi in multi-trophic organic farms of oysters and shrimp: Effects of density and diet

The goal of this study was to demonstrate the feasibility of culturing the seahorse Hippocampus reidi in an organic integrated multi-trophic aquaculture farm that produces the oyster Crassostrea brasiliana and the shrimp Litopenaeus vannamei. Experiments were conducted to evaluate the effects stocking density and food (natural zooplankton, Artemia nauplii, or both) for the juvenile I, which are fish from 1 to 15 days after birth. Stocking density effect was studied on growth and survival of juveniles II from 30 days to commercial size in net cages. Survival of the juvenile I was not affected by stocking densities from 2 to 5 ind L-1 and was greater than 70% in all treatments. Seahorse length, however, was inversely related to stocking density. Both treatments with wild zooplankton promoted higher seahorse survival and growth than diet composed exclusively by Artemia sp. during the first 15 days of life. Juvenile II growth decreased with stocking density from 5 to 40 ind m-3 but survival was not affected by it. The total benefit and proportion of colored animals increased significantly with stocking density. The present study confirms the technical feasibility of organic multi-trophic seahorse production in net cages. Even at the highest density tested the seahorses grew well and could generate high profits

Urban Physiology: City Ants Possess High Heat Tolerance

Urbanization has caused regional increases in temperature that exceed those measured on a global scale, leading to urban heat islands as much as 12°C hotter than their surroundings. Optimality models predict ectotherms in urban areas should tolerate heat better and cold worse than ectotherms in rural areas. We tested these predications by measuring heat and cold tolerances of leaf-cutter ants from South America's largest city (São Paulo, Brazil). Specifically, we compared thermal tolerances of ants from inside and outside of the city. Knock-down resistance and chill-coma recovery were used as indicators of heat and cold tolerances, respectively. Ants from within the city took 20% longer to lose mobility at 42°C than ants from outside the city. Interestingly, greater heat tolerance came at no obvious expense of cold tolerance; hence, our observations only partially support current theory. Our results indicate that thermal tolerances of some organisms can respond to rapid changes in climate. Predictive models should account for acclimatory and evolutionary responses during climate change