72 research outputs found
Experimental Investigation and CFD Modelling of a Thermosyphon-equipped Heat Exchanger used in Low-grade Waste Heat Recovery
Fixed-point elimination in the Intuitionistic Propositional Calculus (extended version)
It is a consequence of existing literature that least and greatest
fixed-points of monotone polynomials on Heyting algebras-that is, the alge-
braic models of the Intuitionistic Propositional Calculus-always exist, even
when these algebras are not complete as lattices. The reason is that these
extremal fixed-points are definable by formulas of the IPC. Consequently, the
-calculus based on intuitionistic logic is trivial, every -formula
being equiv- alent to a fixed-point free formula. We give in this paper an
axiomatization of least and greatest fixed-points of formulas, and an algorithm
to compute a fixed-point free formula equivalent to a given -formula. The
axiomatization of the greatest fixed-point is simple. The axiomatization of the
least fixed- point is more complex, in particular every monotone formula
converges to its least fixed-point by Kleene's iteration in a finite number of
steps, but there is no uniform upper bound on the number of iterations. We
extract, out of the algorithm, upper bounds for such n, depending on the size
of the formula. For some formulas, we show that these upper bounds are
polynomial and optimal.Comment: extended version of arXiv:1601.0040
Psychometric Properties of the Portuguese Version of The PERMA-Profiler
This study evaluates the psychometric properties of a Portuguese version of The PERMA Profiler in a sample of 1258 Portuguese adults (72.3% females) with a mean age of 36.74 years (SD = 11.313). The PERMA Profiler is a questionnaire that assesses the five dimensions of psychological flourishing, according to Seligman’s well-being theory. According to this theory, the well-being pillars known by the acronym PERMA are positive emotions, engagement, relationships, meaning, and accomplishment. Confirmatory factor analysis was conducted to test Seligman’s model. Results support a reasonable model fit for the five-factor model, but based on the results of bootstrap sample analysis the model was not confirmed. There is also a lack of discriminant validity between PERMA constructs and a lack of validity and reliability of engagement factor. Internal consistency was satisfactory for all five sub-scales, except for engagement. Concurrent validity was demonstrated through the strong and very strong correlations between the PERMA factors and Flourishing Scale. A Portuguese version of The PERMA Profiler is a new tool to assist researchers to refine the measurement and understanding of well-being in Portuguese cultures. Future recommendations and limitations are highlighted.info:eu-repo/semantics/publishedVersio
The Effects of Light Quality in the Morphology and Hydrocarbon Production of Botryococcus braunii
Botryococcus braunii is a green, colonial microalga that can produce up to 75
% of its dry weight as liquid hydrocarbons that can be converted to a sustainable
biofuel. Until now, no studies have been performed on the effects of light quality on
B. braunii cell morphology and hydrocarbon production. This investigation focused
on the effects of white light (WL), blue light (BL), green light (GL) and red light (RL)
on cell morphology and hydrocarbon synthesis in B. braunii, strain Guadeloupe
(race B). B. braunii dry biomass increased in WL and RL, but in BL and GL there
was no growth. The average cell size was significantly larger (P < 0.05) in WL
than the average cell size in RL and BL and GL. The amount of hydrocarbons
synthesised was not affected by light quality, with a relative hydrocarbon of 38 %
to 42 % per dry biomass across the different light regimes. Moreover, there was
no change to the composition of hydrocarbons produce by B. braunii in the
different light treatments
MUDANÇAS CLIMÁTICAS E O PROTOCOLO DE QUIOTO: IMPLICAÇÕES PARA INSERÇÃO DA REGIÃO AMAZÔNICA NO MERCADO DE CARBONO
O presente trabalho teve por objetivo analisar o desempenho financeiro de um projeto de reflorestamento sustentável de Teca (Tectona grandis L.f.) na região amazônica, especificamente no Estado do Acre, visando à comercialização de créditos de carbono no âmbito do Protocolo de Quioto por meio do Mecanismo de Desenvolvimento Limpo (MDL). Para o caso específico da região amazônica, foi uma oportunidade para avaliar estratégias de políticas ambientais baseadas em instrumentos econômicos, e suas possíveis repercussões na região. Em relação à análise da viabilidade econômica do projeto como candidato a participação no mercado de carbono, obteve-se primeiramente um rendimento aproximado de 160 Reduções Certificadas de Emissões (RCEs) de carbono equivalente (CO2 eq.) por hectare. Sem a incorporação dos custos e receitas advindas da geração das RCEs, em 1 (um) hectare o projeto é viável a uma taxa mínima de atratividade (TMA) de 10 %, porém, havendo a incorporação das RCEs no projeto, este torna-se inviável economicamente de acordo com todos indicadores utilizados (TIR, VET, VPL, B(C)PE, B/C), passando a ser atrativo somente no caso de aumento da área do projeto para no mínimo 150 hectares. Por meio das análises de sensibilidade, constatou-se que o projeto, submetido à comercialização de créditos de carbono no âmbito do MDL, depende mais de fatores inerentes a produção e comercialização da madeira, do que as próprias RCEs. Para as condições vivenciadas pelos pequenos e médios produtores rurais da região amazônica, em especial no Estado do Acre, a estrutura de custos, principalmente àqueles relacionados à transação no Protocolo de Kyoto, é pouco atrativa.---------------------------------------------This study had as the main objective to analyze the financial performance of a sustainable reforestation project with Teka (Tectona grandis L.f.) in the Amazon region, more specifically in the State of Acre, seeking the commercialization of carbon credits concerning the Kyoto Protocol by the Clean Development Mechanism (CDM). In the specific case of the Amazon region, it was an opportunity to evaluate strategies related to environment policies supposedly based in economics instruments, and their possible impacts on the region. Concerning the feasibility economic analysis of this project as a candidate to participate in the carbon merket it was, firstly, obtained a yield around of 160 Certified Emission Reduction (CER) of CO2 equivalent (CO2e) by hectare. If no incorporation of costs and income from the CERs generation, for 1 hectare, this project would be viable at minimal attractive rate (MAR) of 10 %, on the another hand, taking into account the CER incorporation into this project, it turn to be not viable in economic terms, which would just be economically attractive if the increasing of the project area to at least 150 hectares. Taking into account sensitivity analysis, was verified that the project submitted to commercialization of carbon credits in the CDM setting, depend more on factors related to the timber production and commercialization, than the CER itself. For the conditions observed by small and medium rural producer, living in the Amazon region, in special those living in the State of Acre, the costs structure, mainly those concerning the transaction costs related to Kyoto Protocol, is less attractive.Desenvolvimento Sustentável, Amazônia, Economia Florestal, ustainable Development, Amazon, Forest Economy, Resource /Energy Economics and Policy,
Urinary estrogen metabolites and self-reported infertility in women infected with Schistosoma haematobium
Background
Schistosomiasis is a neglected tropical disease, endemic in 76 countries, that afflicts more than 240 million people. The impact of schistosomiasis on infertility may be underestimated according to recent literature. Extracts of Schistosoma haematobium include estrogen-like metabolites termed catechol-estrogens that down regulate estrogen receptors alpha and beta in estrogen responsive cells. In addition, schistosome derived catechol-estrogens induce genotoxicity that result in estrogen-DNA adducts. These catechol estrogens and the catechol-estrogen-DNA adducts can be isolated from sera of people infected with S. haematobium. The aim of this study was to study infertility in females infected with S. haematobium and its association with the presence of schistosome-derived catechol-estrogens. Methodology/Principal Findings
A cross-sectional study was undertaken of female residents of a region in Bengo province, Angola, endemic for schistosomiasis haematobia. Ninety-three women and girls, aged from two (parents interviewed) to 94 years were interviewed on present and previous urinary, urogenital and gynecological symptoms and complaints. Urine was collected from the participants for egg-based parasitological assessment of schistosome infection, and for liquid chromatography diode array detection electron spray ionization mass spectrometry (LC/UV-DAD/ESI-MSn) to investigate estrogen metabolites in the urine. Novel estrogen-like metabolites, potentially of schistosome origin, were detected in the urine of participants who were positive for eggs of S. haematobium, but not detected in urines negative for S. haematobium eggs. The catechol-estrogens/ DNA adducts were significantly associated with schistosomiasis (OR 3.35; 95% CI 2.32–4.84; P≤0.001). In addition, presence of these metabolites was positively associated with infertility (OR 4.33; 95% CI 1.13–16.70; P≤0.05). Conclusions/Significance
Estrogen metabolites occur widely in diverse metabolic pathways. In view of the statistically significant association between catechol-estrogens/ DNA adducts and self-reported infertility, we propose that an estrogen-DNA adduct mediated pathway in S. haematobium-induced ovarian hormonal deregulation could be involved. In addition, the catechol-estrogens/ DNA adducts described here represent potential biomarkers for schistosomiasis haematobia
Evaluating the ability of an artificial-intelligence cloud-based platform designed to provide information prior to locoregional therapy for breast cancer in improving patient's satisfaction with therapy: the CINDERELLA trial
Background: Breast cancer therapy improved significantly, allowing for different surgical approaches for the same disease stage, therefore offering patients different aesthetic outcomes with similar locoregional control. The purpose of the CINDERELLA trial is to evaluate an artificial-intelligence (AI) cloud-based platform (CINDERELLA platform) vs the standard approach for patient education prior to therapy. Methods: A prospective randomized international multicentre trial comparing two methods for patient education prior to therapy. After institutional ethics approval and a written informed consent, patients planned for locoregional treatment will be randomized to the intervention (CINDERELLA platform) or controls. The patients in the intervention arm will use the newly designed web-application (CINDERELLA platform, CINDERELLA APProach) to access the information related to surgery and/or radiotherapy. Using an AI system, the platform will provide the patient with a picture of her own aesthetic outcome resulting from the surgical procedure she chooses, and an objective evaluation of this aesthetic outcome (e.g., good/fair). The control group will have access to the standard approach. The primary objectives of the trial will be i) to examine the differences between the treatment arms with regards to patients' pre-treatment expectations and the final aesthetic outcomes and ii) in the experimental arm only, the agreement of the pre-treatment AI-evaluation (output) and patient's post-therapy self-evaluation. Discussion: The project aims to develop an easy-to-use cost-effective AI-powered tool that improves shared decision-making processes. We assume that the CINDERELLA APProach will lead to higher satisfaction, better psychosocial status, and wellbeing of breast cancer patients, and reduce the need for additional surgeries to improve aesthetic outcome
Observation of Higgs boson production in association with a top quark pair at the LHC with the ATLAS detector
The observation of Higgs boson production in association with a top quark pair ( tt¯H ), based on the analysis of proton–proton collision data at a centre-of-mass energy of 13 TeV recorded with the ATLAS detector at the Large Hadron Collider, is presented. Using data corresponding to integrated luminosities of up to 79.8 fb −1 , and considering Higgs boson decays into bb¯ , WW⁎ , τ+τ− , γγ , and ZZ⁎ , the observed significance is 5.8 standard deviations, compared to an expectation of 4.9 standard deviations. Combined with the tt¯H searches using a dataset corresponding to integrated luminosities of 4.5 fb −1 at 7 TeV and 20.3 fb −1 at 8 TeV, the observed (expected) significance is 6.3 (5.1) standard deviations. Assuming Standard Model branching fractions, the total tt¯H production cross section at 13 TeV is measured to be 670 ± 90 (stat.) −100+110 (syst.) fb, in agreement with the Standard Model prediction.Peer Reviewe
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