31 research outputs found
Generalized Totalizer Encoding for Pseudo-Boolean Constraints
Pseudo-Boolean constraints, also known as 0-1 Integer Linear Constraints, are
used to model many real-world problems. A common approach to solve these
constraints is to encode them into a SAT formula. The runtime of the SAT solver
on such formula is sensitive to the manner in which the given pseudo-Boolean
constraints are encoded. In this paper, we propose generalized Totalizer
encoding (GTE), which is an arc-consistency preserving extension of the
Totalizer encoding to pseudo-Boolean constraints. Unlike some other encodings,
the number of auxiliary variables required for GTE does not depend on the
magnitudes of the coefficients. Instead, it depends on the number of distinct
combinations of these coefficients. We show the superiority of GTE with respect
to other encodings when large pseudo-Boolean constraints have low number of
distinct coefficients. Our experimental results also show that GTE remains
competitive even when the pseudo-Boolean constraints do not have this
characteristic.Comment: 10 pages, 2 figures, 2 tables. To be published in 21st International
Conference on Principles and Practice of Constraint Programming 201
Estimation of the solubility parameters of model plant surfaces and agrochemicals: a valuable tool for understanding plant surface interactions
Background
Most aerial plant parts are covered with a hydrophobic lipid-rich cuticle, which is the interface between the plant organs and the surrounding environment. Plant surfaces may have a high degree of hydrophobicity because of the combined effects of surface chemistry and roughness. The physical and chemical complexity of the plant cuticle limits the development of models that explain its internal structure and interactions with surface-applied agrochemicals. In this article we introduce a thermodynamic method for estimating the solubilities of model plant surface constituents and relating them to the effects of agrochemicals.
Results
Following the van Krevelen and Hoftyzer method, we calculated the solubility parameters of three model plant species and eight compounds that differ in hydrophobicity and polarity. In addition, intact tissues were examined by scanning electron microscopy and the surface free energy, polarity, solubility parameter and work of adhesion of each were calculated from contact angle measurements of three liquids with different polarities. By comparing the affinities between plant surface constituents and agrochemicals derived from (a) theoretical calculations and (b) contact angle measurements we were able to distinguish the physical effect of surface roughness from the effect of the chemical nature of the epicuticular waxes. A solubility parameter model for plant surfaces is proposed on the basis of an increasing gradient from the cuticular surface towards the underlying cell wall.
Conclusions
The procedure enabled us to predict the interactions among agrochemicals, plant surfaces, and cuticular and cell wall components, and promises to be a useful tool for improving our understanding of biological surface interactions
A study of 82 extended HLA haplotypes in HFE-C282Y homozygous hemochromatosis subjects: relationship to the genetic control of CD8+ T-lymphocyte numbers and severity of iron overload
BACKGROUND: It has been recently demonstrated that CD8+ T-lymphocyte numbers are genetically transmitted in association with the MHC class I region. The present study was designed with the objective of narrowing the region associated with the setting of CD8+ T-lymphocyte numbers in a population of C282Y homozygous hemochromatosis subjects, in whom a high prevalence of abnormally low CD8+ T-lymphocyte counts has been described. METHODS: The study includes 43 C282Y homozygous subjects fully characterized both phenotypically and genotypically. Clinical characterization includes measurements of iron parameters at diagnosis (transferrin saturation and serum ferritin), total body iron stores and T-cell immunophenotyping determined by flow cytometry. Genetic characterization includes HLA class I alleles (A, B and C) and four additional microsatellite markers (D6S265, D6S2222, D6S105 and D6S2239) spanning 5 Megabases in the 6p21.3 region. RESULTS: Eighty-two extended C282Y carrying haplotypes were defined. Single-locus analysis revealed that the HLA-A region was associated with CD8+ T-cell numbers. Multivariate analysis showed that the combinations of the most common HLA-A alleles (HLA-A*03, -A*02 and -A*01) were associated with significantly lower numbers of CD8+ T-lymphocytes (0.30 ± 0.14 × 10(6)/ml), in comparison with subjects carrying only one copy of those alleles (0.46 ± 0.19 × 10(6)/ml) and subjects without any copy of those alleles (0.79 ± 0.15 × 10(6)/ml;p = 0.0001). No differences were observed in CD8+ T-cell counts among control subjects carrying the same combinations of HLA-A alleles (0.47 ± 0.14; 0.45 ± 0.21 and 0.41 ± 0.17 × 10(6)/ml, respectively), therefore not supporting a direct effect of HLA specificity but rather an indirect association with a locus close to HLA-A. Multivariate analysis showed that the combination of the most common HLA-A alleles also have an impact on the clinical expression of HH in terms of iron stores, in males(p = 0.0009). CONCLUSION: The present study provides evidence supporting an inextricable link between extended HLA haplotypes, CD8+ T-lymphocyte numbers and severity of iron overload in hereditary hemochromatosis(HH). It gives additional information to better define a candidate region involved in the regulation of CD8+ T-lymphocyte numbers. A new evolutionary hypothesis concerning the inheritance of the phenotype of low CD8+ T-lymphocyte numbers associated with particular ancestral HLA haplotypes carrying the C282Y mutation and its implication on the clinical heterogeneity of HH is discussed
Heme activates TLR4-mediated inflammatory injury via MyD88/TRIF signaling pathway in intracerebral hemorrhage
<p>Abstract</p> <p>Background</p> <p>Inflammatory injury plays a critical role in intracerebral hemorrhage (ICH)-induced neurological deficits; however, the signaling pathways are not apparent by which the upstream cellular events trigger innate immune and inflammatory responses that contribute to neurological impairments. Toll-like receptor 4 (TLR4) plays a role in inflammatory damage caused by brain disorders.</p> <p>Methods</p> <p>In this study, we investigate the role of TLR4 signaling in ICH-induced inflammation. In the ICH model, a significant upregulation of TLR4 expression in reactive microglia has been demonstrated using real-time RT-PCR. Activation of microglia was detected by immunohistochemistry, cytokines were measured by ELISA, MyD88, TRIF and NF-κB were measured by Western blot and EMSA, animal behavior was evaluated by animal behavioristics.</p> <p>Results</p> <p>Compared to WT mice, TLR4<sup>−/− </sup>mice had restrained ICH-induced brain damage showing in reduced cerebral edema and lower neurological deficit scores. Quantification of cytokines including IL-6, TNF-α and IL-1β and assessment of macrophage infiltration in perihematoma tissues from TLR4<sup>−/−</sup>, MyD88<sup>−/− </sup>and TRIF<sup>−/− </sup>mice showed attenuated inflammatory damage after ICH. TLR4<sup>−/− </sup>mice also exhibited reduced MyD88 and TRIF expression which was accompanied by decreased NF-κB activity. This suggests that after ICH both MyD88 and TRIF pathways might be involved in TLR4-mediated inflammatory injury possibly via NF-κB activation. Exogenous hemin administration significantly increased TLR4 expression and microglial activation in cultures and also exacerbated brain injury in WT mice but not in TLR4<sup>−/− </sup>mice. Anti-TLR4 antibody administration suppressed hemin-induced microglial activation in cultures and in the mice model of ICH.</p> <p>Conclusions</p> <p>Our findings suggest that heme potentiates microglial activation <it>via </it>TLR4, in turn inducing NF-κB activation <it>via </it>the MyD88/TRIF signaling pathway, and ultimately increasing cytokine expression and inflammatory injury in ICH. Targeting TLR4 signaling may be a promising therapeutic strategy for ICH.</p
Development of new microalgae-based sourdough "crostini": functional aspects of Arthrospira platensis (spirulina) addition
The aim of this work was to evaluate the influence of Arthrospira platensis F&M-C256 (spirulina)
incorporation on the nutritional and functional properties of “crostini”, a leavened bakery product
largely consumed in Italy and Europe. Sourdough was used as leavening and fermentation agent and
three concentrations of A. platensis F&M-C256 were tested: 2%, 6% and 10% (w/w). Despite a lower
volume increase compared to the control, the A. platensis F&M-C256 “crostini” doughs reached a
technological appropriate volume after fermentation. At the end of fermentation, no significant
differences in microorganisms concentrations were observed. A. platensis F&M-C256 “crostini” showed
higher protein content compared to the control. Considering the European Commission Regulation on
nutritional claims, “crostini” incorporated with 6% and 10% biomass can be claimed to be a “source
of protein”. Six and ten percent A. platensis “crostini” also presented significantly higher antioxidant
capacity and phenolics. A significantly lower value of in vitro dry matter and protein digestibility
between A. platensis F&M-C256 “crostini” and the control was found. The overall acceptability
decreased with increasing A. platensis F&M-C256 addition. The combination of spirulina biomass
addition and the sourdough technology led to the development of a novel microalgae-based bakery
product with nutritional and functional featuresinfo:eu-repo/semantics/publishedVersio
Investigation of the midgut structure and ultrastructure in Cimex lectularius and Cimex pipistrelli (Hemiptera, Cimicidae)
Cimicidae are temporary ectoparasites, which means that they cannot obtain food continuously. Both Cimex species examined here, Cimex lectularius (Linnaeus 1758) and Cimex pipistrelli (Jenyns 1839), can feed on a non-natal host, C. lectularius from humans on bats, C. pipistrelli on humans, but never naturally. The midgut of C. lectularius and C. pipistrelli is composed of three distinct regions—the anterior midgut (AMG), which has a sack-like shape, the long tube-shaped middle midgut (MMG), and the posterior midgut (PMG). The different ultrastructures of the AMG, MMG, and PMG in both of the species examined suggest that these regions must fulfill different functions in the digestive system. Ultrastructural analysis showed that the AMG fulfills the role of storing food and synthesizing and secreting enzymes, while the MMG is the main organ for the synthesis of enzymes, secretion, and the storage of the reserve material. Additionally, both regions, the AMG and MMG, are involved in water absorption in the digestive system of both Cimex species. The PMG is the part of the midgut in which spherites accumulate. The results of our studies confirm the suggestion of former authors that the structure of the digestive tract of insects is not attributed solely to diet but to the basic adaptation of an ancestor
Aspectos epidemiológicos de um foco de malária no município de São Luis, MA Epidemilogical aspects of a malaria focus in the districts of São Luis, MA
O estudo foi realizado na localidade de Residencial Paraíso, São Luis, Maranhão, de 1999 a 2001, com o objetivo de analisar os aspectos epidemiológicos da malária, tendo sido constatado que a localidade é receptiva e vulnerável. Houve 129 casos, com maior acometimento do sexo masculino e da faixa etária de 20 a 29 anos. O Plasmodium vivax foi o agente responsável pelas infecções, tendo como vetor o Anopheles aquasalis. Foram identificadas evidências de transmissão extradomiciliar.<br>The study was developed in the neighborhood of Residencial Paraíso, São Luis, Maranhão, Brazil, from 1999 to 2001. The aim was to analyze the epidemiological aspects of malaria. The location is receptive and vulnerable to malaria. There were 129 cases. Men from 20 to 29 years of age were most involved. Plasmodium vivax was the agent of all cases and Anopheles aquasalis was the vector. There was no evidence of transmission occurring outside of the houses
Expectativas de resultados frente ao uso de álcool, maconha e tabaco Outcome expectancy considering the use of alcohol, cannabis and tobacco
Este artigo teve como objetivo realizar uma revisão teórica acerca do construto expectativas de resultados frente ao uso de álcool, maconha e tabaco. As expectativas de resultados são determinadas a partir do que as pessoas acreditam acerca dos efeitos de determinada droga, sendo uma variável importante no tratamento de dependentes químicos. Foram realizadas buscas de artigos publicados nas bases de dados MEDLINE, PsycINFO, ProQuest, Ovid, LILACS e Cork, usando os descritores belief, expectancy, expectation, drugs, psychoactive e effect. Os resultados demonstraram que as expectativas de resultados frente ao uso dessas substâncias podem surgir de fontes como: exposição a estímulos condicionados, dependência física, crenças pessoais e culturais e fatores situacionais e ambientais. Conclui-se que ainda há necessidade de novas pesquisas quanto às expectativas relacionadas às diferentes substâncias psicoativas e faixas etárias para uma melhor compreensão deste construto.<br>This article aims to perform a theoretical review about the outcome expectancy construct considering the use of alcohol, cannabis and tobacco. Outcome expectancy is determined by people's belief about the effects of a drug. It is an important variable for the treatment of chemically dependent patients. Searches in the electronic databases MEDLINE, PsycINFO, ProQuest, Ovid, LILACS and Cork were carried out, using the following descriptors: belief, expectancy, expectation, drugs, psychoactive, and effect. Results showed that outcome expectancy considering the use of those substances can be generated from: exposure to conditioning stimuli, physical dependence, personal and cultural beliefs, and situational and environmental factors. In conclusion, there is the need of new researches on expectancies related to psychoactive substances and age groups in order to have a better understanding of this construct