10,257 research outputs found
Ilha das Flores, estatura e peso em crianças dos 6 aos 11 anos.
IV Expedição Científica do Departamento de Biologia – Flores 1989.0s estudos de crescimento físico humano têm-se revelado de grande interesse pois
permitem conhecer as características de diferentes populações e a variabilidade
existente intra e interpopulações. Mas um dos aspectos mais importantes destes
estudos talvez o de, ao se analisar o estado de crescimento e tempo de desenvolvimento
do indivíduo, permitir destrinçar factores que influenciam nefastamente o crescimento.
As diferenças existentes entre populações são o resultado da interacção do ambiente
com os factores genéticos. 0s factores ambientais influênciadores do crescimento são: nutrição, doenças, status sócio-económico, urbanismo, actividade física, stress psicológico, estado do ano e clima. A nutrição é considerado o agente mais influenciador no processo de crescimento (Eveleth, 1979; Malcolm, 1979). Neste estudo consideraram-se a estatura e o peso como os indicadores do crescimento das crianças, de idades entre os 6 e 11 anos, na sua maioria naturais da Ilha das Flores. 0s objectivos foram comparar os valores obtidos com existentes para crianças continentais, descrever a sua variação em função dos indicadores sócio-económicos: profissão do pai, número de irmãos e ordem de nascimento
Neural mechanisms of stimulus generalization in auditory fear conditioning
Dissertation presented to obtain the Ph.D degree in Neuroscience Instituto de Tecnologia Química e Biológica, Universidade Nova de LisboaFear is a physiological trait with a strong weight on survival and
adaptation. Great progress has been made to understand the
mechanisms of fear learning, mainly using auditory fear conditioning
(AFC). In this behavioral paradigm, an initial neutral tone (conditioned
stimulus, CS) acquires aversive predictive properties after successive
pairings with a footshock (unconditioned stimulus, US) and comes to
elicit responses characteristically elicited by threatening stimuli. In this
behavioral paradigm, the amygdala has been identified has a key
neural substrate for associative fear learning, and the site where
unconditioned stimuli (US) and conditioned (CS) auditory stimuli come
to be associated.
Auditory information may reach the amygdala either directly
from the auditory thalamus or indirectly via thalamo-cortico-amygdala
projections. The “high route/low route” hypothesis has thus been
proposed, which claims that the cortical pathway (“high route”) is
crucial for discrimination between fearful and neutral sounds, while the
direct thalamic pathway (“low route”) provides a rapid but less
accurate relay of auditory information to the amygdala. This
hypothesis relies on the assumption that more complex processing
requires cortical activity and that thalamic relay is faster then cortical
transmission to the amygdala. The present work essentially aims at
putting to test this largely accepted hypothesis.Auditory fear
conditioning was used as the behavioral paradigm to unravel the
possible functional explanation for the coexistence of two parallel
auditory pathways converging into the amygdala, and the high route/low route hypothesis was the working model for the identification
of neuronal substrates of auditory discrimination.(...)This work was supported by Fundação para a Ciência e a Tecnologia (Grant SFRH/BD/27500/2006)
A new method based on noise counting to monitor the frontend electronics of the LHCb muon detector
A new method has been developed to check the correct behaviour of the
frontend electronics of the LHCb muon detector. This method is based on the
measurement of the electronic noise rate at different thresholds of the
frontend discriminator. The method was used to choose the optimal discriminator
thresholds. A procedure based on this method was implemented in the detector
control system and allowed the detection of a small percentage of frontend
channels which had deteriorated. A Monte Carlo simulation has been performed to
check the validity of the method
Predicting the critical density of topological defects in O(N) scalar field theories
O(N) symmetric field theories describe many critical
phenomena in the laboratory and in the early Universe. Given N and ,
the dimension of space, these models exhibit topological defect classical
solutions that in some cases fully determine their critical behavior. For N=2,
D=3 it has been observed that the defect density is seemingly a universal
quantity at T_c. We prove this conjecture and show how to predict its value
based on the universal critical exponents of the field theory. Analogously, for
general N and D we predict the universal critical densities of domain walls and
monopoles, for which no detailed thermodynamic study exists. This procedure can
also be inverted, producing an algorithm for generating typical defect networks
at criticality, in contrast to the canonical procedure, which applies only in
the unphysical limit of infinite temperature.Comment: 4 pages, 3 figures, uses RevTex, typos in Eq.(11) and (14) correcte
The Ginzburg regime and its effects on topological defect formation
The Ginzburg temperature has historically been proposed as the energy scale
of formation of topological defects at a second order symmetry breaking phase
transition. More recently alternative proposals which compute the time of
formation of defects from the critical dynamics of the system, have been
gaining both theoretical and experimental support. We investigate, using a
canonical model for string formation, how these two pictures compare. In
particular we show that prolonged exposure of a critical field configuration to
the Ginzburg regime results in no substantial suppression of the final density
of defects formed. These results dismiss the recently proposed role of the
Ginzburg regime in explaining the absence of topological defects in 4He
pressure quench experiments.Comment: 8 pages, 5 ps figure
NOSTROMO - D5.1 - ATM Performance Metamodels - Preliminary Release
This deliverable presents the results obtained with the meta-modelling process presented in D3.1 and D3.2 applied to the two micromodels (or simulators), Mercury and FLITAN, themselves implementing concepts from four SESAR solutions, PJ01.01, PJ07.02, PJ08-01, and PJ02.08.
The objective of the meta-modelling process is explained briefly again in the introduction, in particular with respect to performance assessment. The rationale for the selection of the SESAR solutions implemented in the simulators are briefly explained too.
The simulators are presented in two distinct chapters. First, a general presentation of each simulator is given, with past challenges and development, before explaining the development steps carried out to implement the concepts from the chosen solutions. Domain research questions that could be answered by these implementations are highlighted along the way.
The meta-modelling process is then briefly explained again, followed by the results obtained with the two simulators, in distinct sections. The results highlight the performance of the meta-model with respect to approximating the output of the micromodels, but not the performance of the models themselves with respect to the research questions, which will be explored in WP7 instead.
The deliverable closes with some considerations on the meta-modelling performance and next steps for this line of work
The Creation of Defects with Core Condensation
Defects in superfluid 3He, high-Tc superconductors, QCD colour superfluids
and cosmic vortons can possess (anti)ferromagnetic cores, and their
generalisations. In each case there is a second order parameter whose value is
zero in the bulk which does not vanish in the core. We examine the production
of defects in the simplest 1+1 dimensional scalar theory in which a second
order parameter can take non-zero values in a defect core. We study in detail
the effects of core condensation on the defect production mechanism.Comment: 9 pages, 7 figures, small corrections, 2 references added, final
version to be published in PR
The effect of nanocoatings enriched with essential oils on ‘Rocha’ pear long storage
The effect of coating 'Rocha' pears with alginate-based nanoemulsions enriched with lemongrass essential oil (LG) or citral (Cit) was investigated. Fruit were treated with the nanoemulsions: sodium alginate 2% (w/w) + citral 1% (w/w) (Cit1%); sodium alginate 2% (w/w) + citral 2% (w/w) (Cit2%); sodium alginate 2% (w/w) + lemongrass 1.25% (w/w) (LG1.25%); sodium alginate 2% (w/w) + lemongrass 2.5% (w/w) (LG2.5%). Then, fruit were stored at 0 °C and at 95% relative humidity, for six months. Fruit samples were taken after two, four and six months, and then placed at 22 °C. Upon removal and after 7 d shelf-life, fruit were evaluated for colour CIE (L*, h◦), firmness, soluble solids content (SSC), titratable acidity (TA), weight loss, electrolytic leakage, microbial growth, symptoms of superficial scald and internal browning. All nanoemulsions had droplets in the nano range <500 nm, showed uniformity of particle size and stable dispersion. Cit-nanoemulsions had lower droplet size and higher stability than LG. No nanoemulsion showed cytotoxicity. Coatings reduced fruit colour evolution and preserved better firmness than control. After shelf-life, better firmness was found in LG-coated fruit. Coatings did not affect SSC and TA. Microbial growth was below the safety limits in all treatments. Fruit treated with LG-nanoemulsions did not show scald symptoms and panelists preferred LG1.25% coated fruit. Cit2% treated fruit showed the highest scald and internal browning symptoms, while LG1.25% did not show any disorders. This study suggests that LG-nanocoatings have the potential for preserving the quality of 'Rocha' pear.FCT (SFRH/BPD/108831/2015); UID/BIA/04325/2019/ UID/Multi/00631/2019/ UID/AMB/50017/2019info:eu-repo/semantics/publishedVersio
Anisakis infection in allis shad, Alosa alosa (Linnaeus, 1758), and twaite shad, Alosa fallax (Lacépède, 1803), from Western Iberian Peninsula Rivers : zoonotic and ecological implications
Acknowledgments The authors would like to thank M. N. Cueto and J.M. Antonio (ECOBIOMAR) for their excellent technical support and also Rodrigo López for making the map of the study area. We also thank the personal of the Vigo IEO, for providing information about shad captures at sea collected on the basis of national program (AMDES) included in the European Data Collection Framework (DCF) project. We are also grateful to Comandancia Naval de Tui for providing fishing data. M. Bao is supported by a PhD grant from the University of Aberdeen and also by financial support of the contract from the EU Project PARASITE (grant number 312068). This study was partially supported by a PhD grant from the Portuguese Foundation for Science and Technology (FCT) SFRH/BD/44892/2008) and partially supported by the European Regional Development Fund (ERDF) through the COMPETE—Operational Competitiveness Programme and national funds through Foundation for Science and Technology (FCT), under the project BPEst-C/MAR/ LA0015/2013. The authors thank the staff of the Station of Hydrobiology of the USC BEncoro do Con^ due their participation in the surveys. This work has been partially supported by the project 10PXIB2111059PR of the Xunta de Galicia and the project MIGRANET of the Interreg IV BSUDOE (South-West Europe) Territorial Cooperation Programme (SOE2/P2/E288). D.J. Nachón is supported by a PhD grant from the Xunta de Galicia (PRE/2011/198)Peer reviewedPostprin
- …