1,321 research outputs found
Management of estuarine beaches on the Amazon coast though the application of recreational carrying capacity indices
The purpose of this paper is to determine the Recreational Carrying Capacity of three estuarine beaches (Colares, Marudá and Murubira) on the Amazon coast of Brazil, based on the combined assessment of natural conditions and visitor facilities. In the final analysis, the carrying capacity of Colares beach was estimated to be 1089 visitors per day, and that of Murubira beach, 238 visitors per day. At Marudá beach, however, the inadequate quality of the water resulted in an RCC of zero, indicating that the beach should not be visited for recreational use. The results of this study may provide a valuable diagnostic tool for the development of future state and municipal coastal management programs. We believe that the procedures adopted in this study are applicable to other estuarine beaches on the Amazon coast, as well as in other estuarine beaches elsewhere with similar natural characteristics.Peer ReviewedPostprint (author's final draft
Mesenchymal stem cells secretome as a modulator of the neurogenic niche: Basic insights and therapeutic opportunities
Neural stem cells (NSCs) and mesenchymal stem cells (MSCs) share few characteristics apart from self-renewal and multipotency. In fact, the neurogenic and osteogenic stem cell niches derive from two distinct embryonary structures; while the later originates from the mesoderm, as all the connective tissues do, the first derives from the ectoderm. Therefore, it is highly unlikely that stem cells isolated from one niche could form terminally differentiated cells from the other. Additionally, these two niches are associated to tissues/systems (e.g., bone and central nervous system) that have markedly different needs and display diverse functions within the human body. Nevertheless they do share common features. For instance, the differentiation of both NSCs and MSCs is intimately associated with the bone morphogenetic protein family. Moreover, both NSCs and MSCs secrete a panel of common growth factors, such as nerve growth factor (NGF), glial derived neurotrophic factor (GDNF), and brain derived neurotrophic factor (BDNF), among others. But it is not the features they share but the interaction between them that seem most important, and worth exploring; namely, it has already been shown that there are mutually beneficially effects when these cell types are co-cultured in vitro. In fact the use of MSCs, and their secretome, become a strong candidate to be used as a therapeutic tool for CNS applications, namely by triggering the endogenous proliferation and differentiation of neural progenitors, among other mechanisms. Quite interestingly it was recently revealed that MSCs could be found in the human brain, in the vicinity of capillaries. In the present review we highlight how MSCs and NSCs in the neurogenic niches interact. Furthermore, we propose directions on this field and explore the future therapeutic possibilities that may arise from the combination/interaction of MSCs and NSCs.Portuguese Foundation for Science and Technology (FCT; IF Development Grant to AJS; IF Starting Grant to BMC); Bial Foundation (Grant 217/12 to JCS); co-funded by Programa Operacional Regional do Norte (ON.2 – O Novo Norte), ao abrigo do Quadro de Referência Estratégico Nacional (QREN),atravésdoFundoEuropeudeDesenvolvimentoRegional (FEDER)
Promover a continuidade do ensino antes da ocorrência de um sismo
Portugal and Spain are countries prone to earthquake hazard. An earthquake that occurs in the sea
may trigger a tsunami threat, so in this case they are also prone to tsunami. After a disaster, the size and
severity of the event, undermines the availability of systems and services to function properly, resulting in
losses and impacts in human, social, environmental and economic spheres. One of the potential negative
effectsfor children’s education is caused by damaged school buildings and lack of road access to schools. The
PERSISTAH project aims to study the seismic risk of primary schools located in the regions of Algarve
(Portugal) and Huelva (Spain). The present research has specific objectives: 1) to improve school seismic
safety; 2) to protect learners and education workers from death, injury and harm in schools; 3) to safeguard
education investments; and 4) to strengthen risk reduction and resilience through educationThis project was funded by the INTERREG-POCTEP España-Portugal program and the European Regional
Development Fund.info:eu-repo/semantics/publishedVersio
Assessment of metallic element contamination in sediments from the Santos - São Vicente Estuarine System
Three approaches were applied to evaluate metal contamination in 41 sediment samples from the Santos - São Vicente Estuarine System: normalization to Al, statistical analysis and sediment quality guidelines (SQGs). The results showed increases in the concentrations of Zn, Ni, Pb, Cd, Cr and Hg, which seemed to be associated with human activities. The levels of Al, Fe and Co probably were associated with crustal material or natural weathering processes. About 45% of the samples presented concentrations exceeding TEL-ERL, levels occasionally associated with adverse biological effects. Four of these samples presented concentrations above PEL-ERM, levels frequently associated with adverse biological effects.FAPES
Unveiling the Dynamics of the Universe
We explore the dynamics and evolution of the Universe at early and late
times, focusing on both dark energy and extended gravity models and their
astrophysical and cosmological consequences. Modified theories of gravity not
only provide an alternative explanation for the recent expansion history of the
universe, but they also offer a paradigm fundamentally distinct from the
simplest dark energy models of cosmic acceleration. In this review, we perform
a detailed theoretical and phenomenological analysis of different modified
gravity models and investigate their consistency. We also consider the
cosmological implications of well motivated physical models of the early
universe with a particular emphasis on inflation and topological defects.
Astrophysical and cosmological tests over a wide range of scales, from the
solar system to the observable horizon, severely restrict the allowed models of
the Universe. Here, we review several observational probes -- including
gravitational lensing, galaxy clusters, cosmic microwave background temperature
and polarization, supernova and baryon acoustic oscillations measurements --
and their relevance in constraining our cosmological description of the
Universe.Comment: 94 pages, 14 figures. Review paper accepted for publication in a
Special Issue of Symmetry. "Symmetry: Feature Papers 2016". V2: Matches
published version, now 79 pages (new format
Germinação in vitro do pólen de cupuaçuzeiro.
Estudo de vários parâmetros, como a caracterização de cinco estádios da antese da flor de cupuaçuzeiro e a determinação do tamanho da amostra para a contagem dos grãos de pólen germinados, com o objetivo de desenvolver uma metodologia para germinação in vitro do pólen de cupuaçuzeiro.bitstream/CPAA-2009-09/8139/1/BP_8.pd
Power quality phenomena in electrified railways: Conventional and new trends in power quality improvement toward public power systems
Nowadays, railway electrification is the most efficient way to power the trains. However, power quality (PQ) phenomena toward public power systems (PPSs) have always a main concern to the railway operators, especially when the single phase traction power system is interconnected to the three phase PPS. The last decades have witnessed an on going evolution of PQ improvement and traction power supply systems, contributing to diminish the negative impacts of AC railway networks on PQ of the three phase PPS. In this context, this paper presents a global overview of the PQ phenomena in AC railway electrification, as well as the impacts of the potential hazards on the safe operation of electrified railways. The paper also reviews PQ improvement methods from the early use of AC railway electrification until the emergence of the new power electronics devices in railways industry.Mohamed Tanta was supported by FCT (Fundação para a Ciência e Tecnologia) PhD grant with a reference PD/BD/127815/2016. This work has been supported by COMPETE: POCI-01-0145–FEDER–007043 and FCT within the Project Scope: UID/CEC/00319/2013.info:eu-repo/semantics/publishedVersio
Técnica para germinação do pólen de cupuaçuzeiro, em laboratório.
Este trabalho teve como objetivo descrever a técnica inédita do preparo da solução e do meio para a germinação do pólen de cupuaçuzeiro usada por Antonio et al. (2000)
Técnica para germinação do pólen de cupuaçuzeiro, em laboratório.
Este trabalho tem como objetivo descrever a técnica inédita do preparo da solução e do meio para a germinação do pólen de cupuaçuzeiro usada por Antonio et al. (2000)
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