1,466 research outputs found
Meta-Level Inference and Program Verification
In [Bundy and Sterling 81] we described how meta-level inference was useful for controlling search and deriving control information in the domain of algebra. Similar techniques are applicable to the verification of logic programs. A developing meta-language is described, and an explicit proof plan using this language is given. A program, IMPRESS, is outlined which executes this plan
The effect of drought on energy and water vapour exchange above a mediterranean C3/C4 grassland in Southern Portugal
We studied the seasonal and interannual variation in surface energy fluxes – net radiation
(Rn), soil heat (G), sensible heat (H) and latent heat (lE) fluxes – and water vapour exchange
above a Mediterranean C3/C4 grassland in Portugal, during two hydrological years, i.e., the
period from 1 October to 30 September of the next year, of contrasting rainfall. The first year,
2004–2005, was dry, with total precipitation 45% below the long-term mean (669 mm),
whereas the following, 2005–2006, was normal, with total precipitation only 12% above
the long-term mean. Soil water availability and plant canopy growth were the most
important factors in determining the seasonal and interannual variation in energy partitioning.
During autumn, winter and early spring the ratio lE/Rn dominated over H/Rn, in the
two years of the study, whereas on an annual basis, the major portion of Rn was consumed in
H and lE in the dry and normal years, respectively. The total annual evapotranspiration (E)
and its daily maximum were 316 mmand 2.8 mmper day, respectively, for the dry year, and
481mmand 4.5 mmper day for the normal year. After the senescence of the C3 species, the
warm-season perennial C4 grass, Cynodon dactylon L., played a preponderant role in maintaining
substantial E rates contributing to soil water depletion. In this study, we assessed the
effects of the most relevant biophysical factors on surface conductance (gs) and E.We found
that the Priestley–Taylor coefficient and gs were substantially reduced when the average
volumetric soil moisture content in the top 15 cm of the soil profile dropped below 14%. With
abundant soil moisture and leaf area index (LAI) greater than 1, the evaporative fractions
(lE/Rn) were linearly related to LAI (R2 = 0.73). The decoupling coefficient (V) ranged from a
maximum of about 0.7, under non-limiting soil moisture conditions, to a minimumof about
0.1, under soil moisture deficit. This suggests that E was strongly controlled by the vapour
pressure deficit of the air and gs during the periods with limiting soil moisture
Nitric oxide synthesis and biological functions of nitric oxide released from ruthenium compounds
During three decades, an enormous number of studies have demonstrated the critical role of nitric oxide (NO) as a second messenger engaged in the activation of many systems including vascular smooth muscle relaxation. The underlying cellular mechanisms involved in vasodilatation are essentially due to soluble guanylyl-cyclase (sGC) modulation in the cytoplasm of vascular smooth cells. sGC activation culminates in cyclic GMP (cGMP) production, which in turn leads to protein kinase G (PKG) activation. NO binds to the sGC heme moiety, thereby activating this enzyme. Activation of the NO-sGC-cGMP-PKG pathway entails Ca2+ signaling reduction and vasodilatation. Endothelium dysfunction leads to decreased production or bioavailability of endogenous NO that could contribute to vascular diseases. Nitrosyl ruthenium complexes have been studied as a new class of NO donors with potential therapeutic use in order to supply the NO deficiency. In this context, this article shall provide a brief review of the effects exerted by the NO that is enzymatically produced via endothelial NO-synthase (eNOS) activation and by the NO released from NO donor compounds in the vascular smooth muscle cells on both conduit and resistance arteries, as well as veins. In addition, the involvement of the nitrite molecule as an endogenous NO reservoir engaged in vasodilatation will be described
Impact of dietary plant protein levels on the consumer acceptability of senegalese sole (Solea senegalensis Kaup, 1858)
The aim of the present work was to assess the impact of different vegetable diets in the sensory
acceptability of Senegalese sole.This work was carried out by Project PROAMBIENTE for enhancing SMEs organizational and management structure
to enter foreign markets. PROAMBIENTE has the financial support of Quadro de Referência Estratégico Nacional –
QREN and Programa Operacional Regional do Norte – ON2, supported by the European fund for regional
development FEDER
Monte Carlo study of the critical temperature for the planar rotator model with nonmagnetic impurities
We performed Monte Carlo simulations to calculate the
Berezinskii-Kosterlitz-Thouless (BKT) temperature for the
two-dimensional planar rotator model in the presence of nonmagnetic impurity
concentration . As expected, our calculation shows that the BKT
temperature decreases as the spin vacancies increase. There is a critical
dilution at which . The effective interaction
between a vortex-antivortex pair and a static nonmagnetic impurity is studied
analytically. A simple phenomenological argument based on the pair-impurity
interaction is proposed to justify the simulations.Comment: 5 pages, 5 figures, Revetex fil
Massive lower gastrointestinal bleeding from idiopathic ileocolonic varix: report of a case
Dis Colon Rectum. 2006 Apr;49(4):524-6.
Massive lower gastrointestinal bleeding from idiopathic ileocolonic varix: report of a case.
Lopes LM, Ramada JM, Certo MG, Pereira PR, Soares JM, Ribeiro M, Areias J, Pinho C.
SourceGastroenterology Department, Hospital Geral Santo António, Porto, Portugal. [email protected]
Abstract
Idiopathic varices of the entire colon are very rare. We report on a 64-year-old patient with massive lower gastrointestinal hemorrhage from an extensive ileocolonic varix. Diagnosis was established by colonoscopy. The patient underwent an emergency ileocolectomy with satisfactory results. This rare case shows the importance of colonoscopy in the evaluation of patients with lower gastrointestinal hemorrhage and reminds us that sometimes the diagnosis is not what we expect. Recognition of this abnormality is important because varices may be the cause of massive lower gastrointestinal hemorrhage.
PMID: 16395635 [PubMed - indexed for MEDLINE
Social capital and factors associated with the caries experience in adults : a population-based study in Brazil
The objective of this study was to investigate the experience of caries related to social capital and associated factors in adults in large-scale population-based study. A Cross-sectional study was performed in 163 municipalities in the State of São Paulo, Brazil (SBSP-2015). 17,560 people were evaluated, of which 6051 were adults aged 35-44 years. Hierarchical logistic regression analysis was proposed. Outcome variables (decayed teeth, missing teeth and DMFT) and independent variables were included in the model, considering the distal (income and schooling); intermediate (social capital) and proximal levels (sex and ethnicity). Results showed that income up to 1,500 reais - US$ 367.6 in 11/11/2019 - (OR = 1.91;1.75-2.08), schooling up to 8 years (OR = 1.32;1.12-1.56) and non-white ethnicity (OR = 1.54;1.35-1.76) were more likely to have decayed teeth. Income up to 1500 reais (OR = 1.29;1.15-1.44), schooling up to 8 years (OR = 2.13;1.90-2.38), low social capital (OR = 1.84;1.65-2.04), medium social capital (OR = 1.15;1.01-1.30) and females were more likely to have lost teeth (OR = 1.13;1.03-1.23). Schooling up to 8 years (OR = 1.51;1.35-1.69), low social capital (OR = 1.25; 1.14-1.37) and female (OR = 1.40,1.19-1.53) were associated with DMFT. It was concluded that sociodemographic factors and low social capital were associated with the experience of caries, which should be taken into account in the formulation of public policies3
A systematic literature review on the semi-automatic configuration of extended product lines
Product line engineering has become essential in mass customisation given its ability to reduce production costs and time to market, and to improve product quality and customer satisfaction. In product line literature, mass customisation is known as product configuration. Currently, there are multiple heterogeneous contributions in the product line configuration domain. However, a secondary study that shows an overview of the progress, trends, and gaps faced by researchers in this domain is still missing. In this context, we provide a comprehensive systematic literature review to discover which approaches exist to support the configuration process of extended product lines and how these approaches perform in practice. Extend product lines consider non-functional properties in the product line modelling. We compare and classify a total of 66 primary studies from 2000 to 2016. Mainly, we give an in-depth view of techniques used by each work, how these techniques are evaluated and their main shortcomings. As main results, our review identified (i) the need to improve the quality of the evaluation of existing approaches, (ii) a lack of hybrid solutions to support multiple configuration constraints, and (iii) a need to improve scalability and performance conditions
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