Papers by Eric Soares silva
Resumos do..., 2019
The aim of this study was to evaluate the influence of high-intensity ultrasound (HIUS) specific ... more The aim of this study was to evaluate the influence of high-intensity ultrasound (HIUS) specific energy on the microbial inactivation and physicochemical properties of gallic acid enriched-apple juice. The beverage was enriched with 0.1 g gallic acid per100 g apple juice. The treatments were performed using two HIUS processes, low power and long time (LPLT) and high power and short time (HPST); both operating at the same specific energy levels (1, 3, 5, and 7 kJ/g). The most effective aerobic mesophilic heterotrophic bacteria (AMHB) inactivation was obtained by using the HPST process at the specific energies of 5 and 7 kJ/g, which of them resulted in the same log reduction of 3.14. Physicochemical properties, such as pH, soluble solids content, zeta potential, and color difference (ΔE) were not influenced by the HIUS processes or specific energy levels. The gallic acid content also was preserved in all HIUS treatments.
Resumos do..., 2019
There is a new industrial trend, which aims to develop new processes in order to better exploit t... more There is a new industrial trend, which aims to develop new processes in order to better exploit the agro-industrial waste, taking advantage of all the fractions originated from a single raw material. Therefore, this study presents the processing of the annatto seed aiming for the integral use of this vegetable matrix. The effects of high-intensity ultrasound (HIUS) technology on the chemical modification of the annatto seed starch through the insertion of the lipophilic component octenyl succinic anhydride (OSA) were evaluated aiming to develop of a new emulsifier for food applications. The chemical modification procedure of the starch molecules was performed employing different HIUS energy density levels (0, 1.2, 2.4 and 3.6 kJ / mL).
Chemical Reviews, 2015
Introduction: properties and potential applications of glycerol ethers 2. Glycerol ether synthesi... more Introduction: properties and potential applications of glycerol ethers 2. Glycerol ether synthesis from already existing industrial building blocks 2.1. From 3-chloro-1,2-propanediol as starting material 2.2. From allyl halides or allyl alcohols as starting materials 2.3. From epichlorohydrin as starting material 2.4. From glycidol as starting material 2.5. Glycerol ethers via hydrolysis of epoxides The synthesis of glycerol ethers was earlier studied in order to modify the hydrophilic (glycerol, diglycerol, triglycerol) and hydrophobic parts (branched or linear chains) allowing the possibility to develop a large class of compounds with useful biological and physical properties. 5 Several studies have demonstrated their original surfactant properties compared to classical nonionic surfactants such as polyethylene glycols (PEGs) synthesized from petrochemicals. 6,7,8,9,10,11 For example, Aubry recently defined hydrotropic properties for some short alkylated chain glycerol mono-ethers (GMEs). 12 These compounds also possess some original biological properties such as immunostimulating, 13 antimicrobial, 14,15,16 and antitumor activity 17,18,19 or can be used in equine anesthesia. 20 This class of compound is also present as additives in the pharmaceutical domain, as they allow the transport of active substances through the skin, 21 lipid membrane 22 and hemato-encephalic barrier. 23,24,25 They can be found in dermatological preparations 26,27,28 for the treatment of allergic diseases, especially asthma, 29 as they have activity towards mycobacteria. 30,31,32,33,34 Cosmetics 35,36 also use GMEs, specifically in the composition of deodorants, 37,38 hair dyes, 39 shampoos 40,41 and creams for the skin. 42,43 One of the most widespread molecules used in skin creams is 3-[(2-ethylhexyl)oxy]-1,2propanediol which is also known as SENSIVA® SC50. This compound is industrially synthesized from epichlorohydrin (ECH) by SCHÜLKE & MAYR (Scheme 2). 44 The KAO company produces glycerol isostearyl ether which is commercialized as PENETOL GE-IS. 45 GMEs are also used as emulsifiers 46 and in liquid detergent compositions. 47,48,49 They are present in the formulation of inks, 50,51 herbicides, 52 polymers, 53,54 and lubricants. 55 Furthermore, glycerol diethers increase performance as fuel additives. 56,57 Finally, this class of compound can also be used as intermediates in the preparation of chemicals or materials for example 1,3-dioxolan-2
Astronomy & Geophysics, 2007
Eric de Silva champions a group of early-career scientists who have been finding out more about t... more Eric de Silva champions a group of early-career scientists who have been finding out more about the use of science to sell untested and often untestable devices to an unsuspecting public.
Crystal Engineering, 2003
The crystal structure of the 2:1 1,6-diamino-hexane: para-H-calix-4-arene-25,27-di-phosphonate co... more The crystal structure of the 2:1 1,6-diamino-hexane: para-H-calix-4-arene-25,27-di-phosphonate complex shows a designed encapsulation of a calix-arene dimer within a three-dimensional matrix formed by the diamine molecules, the slight mismatch in the length of the diamine molecules compared to the size of the calix-arene molecule is compensated by chain folding in the diamine
Human Genomics, 2004
We havestudied the recombination rateb ehaviour ofaseto f140genesw hich werei nvestigated for the... more We havestudied the recombination rateb ehaviour ofaseto f140genesw hich werei nvestigated for theirp otentialimportance in inflammatorydisease.Each genewasextensively sequenced in24individuals ofAfricandescent and23 individuals ofEuropeandescent,and the recombination process wass tudied separately int he two population samples. The results obtained fromt he two populations were highly correlated, suggestingthatdemographic biasdoesn ot affecto ur population genetic estimation procedure.We founde vidence that levels ofrecombination correlatewithlevels ofnucleotide diversity.High markerdensity allowed us to studyr ecombination ratevariation on avery finespatials cale.We foundthatabout 40p ercent ofg eness howed evidence ofuniform recombination,whilea pproximately 12 percent ofgenescarried distinctsignaturesofrecombination hotspots. Onstudyingthe locations ofthesehotspots,wefoundthattheyare not always confined to introns but canalso stretch across exons. Aninvestigation ofthe proteinp roducts oftheseg eness uggested that recombination hotspots cans ometimess eparatee xons belongingto different proteindomains; however,thiso ccurs much less frequently thanm ightbe expected based on evolutionary studiesinto the origins ofrecombination. Thiss uggests thatevolutionary analysiso fthe recombination process isgreatly aided byconsideringnucleotide sequencesandproteinp roducts jointly.
RNA (New York, N.Y.), 2012
The essential eukaryote release factor eRF1, encoded by the yeast SUP45 gene, recognizes stop cod... more The essential eukaryote release factor eRF1, encoded by the yeast SUP45 gene, recognizes stop codons during ribosomal translation. SUP45 nonsense alleles are, however, viable due to the establishment of feedback-regulated readthrough of the premature termination codon; reductions in full-length eRF1 promote tRNA-mediated stop codon readthrough, which, in turn, drives partial production of full-length eRF1. A deterministic mathematical model of this eRF1 feedback loop was developed using a staged increase in model complexity. Model predictions matched the experimental observation that strains carrying the mutant SUQ5 tRNA (a weak UAA suppressor) in combination with any of the tested sup45(UAA) nonsense alleles exhibit threefold more stop codon readthrough than that of an SUQ5 yeast strain. The model also successfully predicted that eRF1 feedback control in an SUQ5 sup45(UAA) mutant would resist, but not completely prevent, imposed changes in eRF1 expression. In these experiments, the...
Revue internationale d'éducation de Sèvres, 2013
Revue internationale d'éducation de Sèvres 64 | 2013 Les espaces scolaires Redéfinir le pouvoir e... more Revue internationale d'éducation de Sèvres 64 | 2013 Les espaces scolaires Redéfinir le pouvoir et l'espace au sein de l'école Une expérience d'autogestion communautaire au Chili Redefining authority and space within the school. An experience of community self-management in Chile Redefinir el poder y el espacio dentro de la escuela. Una experiencia de autogestión comunitaria en Chile
Le Journal des psychologues, 2009
Distribution électronique Cairn.info pour Martin Média. © Martin Média. Tous droits réservés pour... more Distribution électronique Cairn.info pour Martin Média. © Martin Média. Tous droits réservés pour tous pays. La reproduction ou représentation de cet article, notamment par photocopie, n'est autorisée que dans les limites des conditions générales d'utilisation du site ou, le cas échéant, des conditions générales de la licence souscrite par votre établissement. Toute autre reproduction ou représentation, en tout ou partie, sous quelque forme et de quelque manière que ce soit, est interdite sauf accord préalable et écrit de l'éditeur, en dehors des cas prévus par la législation en vigueur en France. Il est précisé que son stockage dans une base de données est également interdit.
Le Journal des psychologues, 2013
The Astrophysical Journal, 2002
We assess the global properties of associated C ivλλ1548,1550 absorption lines measured in the sp... more We assess the global properties of associated C ivλλ1548,1550 absorption lines measured in the spectra of radio-loud quasars drawn from a near-complete, low-frequency selected sample. The observations span restframe C iv in two redshift ranges-0.7 < z < 1.0 and 1.5 < z < 3.0-which were targetted in the UV with HST/STIS and in the optical with ground-based telescopes, respectively. First, we corroborate trends for C iv associated absorption to be found preferentially in steep-spectrum and lobedominated quasars, implying the absorbing material tends to lie away from the radio-jet axis. Furthermore, we find a clear anticorrelation between C iv absorption strength and the projected linear size of steep-spectrum quasars, indicative of an evolutionary sequence. We also find that heavily-absorbed quasars are systematically redder, implying dust is mixed in with the C iv-absorbing gas. No redshift dependence was found in any of the trends considered. These new results show that radio sources are triggered in galaxies which are exceptionally rich in gas and dust, which then dissipates on a timescale comparable with, but less than, that of the radio source. This observational sequence, together with the lack of redshift-dependence, points to a direct causal link between the event which triggered the radio source and the build-up of absorbing gas and dust, whose make-up is tantalisingly similar to the products of a post-merger starburst. Thus, these new results provide direct evidence for the clearing of absorbing material around quasars with time, as well as the probable association of starburst activity with the onset of the radio activity in AGN.
Proceedings of the National Academy of Sciences, 2008
After the completion of the human and other genome projects it emerged that the number of genes i... more After the completion of the human and other genome projects it emerged that the number of genes in organisms as diverse as fruit flies, nematodes, and humans does not reflect our perception of their relative complexity. Here, we provide reliable evidence that the size of protein interaction networks in different organisms appears to correlate much better with their apparent biological complexity. We develop a stable and powerful, yet simple, statistical procedure to estimate the size of the whole network from subnet data. This approach is then applied to a range of eukaryotic organisms for which extensive protein interaction data have been collected and we estimate the number of interactions in humans to be ≈650,000. We find that the human interaction network is one order of magnitude bigger than the Drosophila melanogaster interactome and ≈3 times bigger than in Caenorhabditis elegans .
Philosophical Transactions of the Royal Society B: Biological Sciences, 2005
The variation of the recombination rate along chromosomal DNA is one of the important determinant... more The variation of the recombination rate along chromosomal DNA is one of the important determinants of the patterns of linkage disequilibrium. A number of inferential methods have been developed which estimate the recombination rate and its variation from population genetic data. The majority of these methods are based on modelling the genealogical process underlying a sample of DNA sequences and thus explicitly include a model of the demographic process. Here we propose a different inferential procedure based on a previously introduced framework where recombination is modelled as a point process along a DNA sequence. The approach infers regions containing putative hotspots based on the inferred minimum number of recombination events; it thus depends only indirectly on the underlying population demography. A Poisson point process model with local rates is then used to infer patterns of recombination rate estimation in a fully Bayesian framework. We illustrate this new approach by app...
Journal of Theoretical Biology, 2010
Translation is the final stage of gene expression where messenger RNA is used as a template for p... more Translation is the final stage of gene expression where messenger RNA is used as a template for protein polymerisation from appropriate amino acids. Release of the completed protein requires a release factor protein acting at the termination/stop codon to liberate it. In this paper we focus on a complex feedback control mechanism involved in the translation and synthesis of release factor proteins, which has been observed in different systems. These release factor proteins are involved in the termination stage of their own translation. Further, mutations in the release factor gene can result in a premature stop codon. In this case translation can result either in early termination and the production
Journal of The Royal Society Interface, 2012
Using sequence data to infer population dynamics is playing an increasing role in the analysis of... more Using sequence data to infer population dynamics is playing an increasing role in the analysis of outbreaks. The most common methods in use, based on coalescent inference, have been widely used but not extensively tested against simulated epidemics. Here, we use simulated data to test the ability of both parametric and non-parametric methods for inference of effective population size (coded in the popular BEAST package) to reconstruct epidemic dynamics. We consider a range of simulations centred on scenarios considered plausible for pandemic influenza, but our conclusions are generic for any exponentially growing epidemic. We highlight systematic biases in non-parametric effective population size estimation. The most prominent such bias leads to the false inference of slowing of epidemic spread in the recent past even when the real epidemic is growing exponentially. We suggest some sampling strategies that could reduce (but not eliminate) some of the biases. Parametric methods can c...
Journal of The Royal Society Interface, 2005
The analysis of molecular networks, such as transcriptional, metabolic and protein interaction ne... more The analysis of molecular networks, such as transcriptional, metabolic and protein interaction networks, has progressed substantially because of the power of models from statistical physics. Increasingly, the data are becoming so detailed—though not always complete or correct—that the simple models are reaching the limits of their usefulness. Here, we will discuss how network information can be described and to some extent quantified. In particular statistics offers a range of tools, such as model selection, which have not yet been widely applied in the analysis of biological networks. We will also outline a number of present challenges posed by biological network data in systems biology, and the extent to which these can be addressed by new developments in statistics, physics and applied mathematics.
Journal of Inclusion Phenomena and Macrocyclic Chemistry, 2006
Electrospray Ionization Mass Spectrometry (ESI/MS) has been used to determine the association con... more Electrospray Ionization Mass Spectrometry (ESI/MS) has been used to determine the association constants (K As) and binding stoichiometries for parent para-Sulphonato-calix[n]arenes and their derivatives with bovine serum albumin (BSA). K A values were determined by titration experiments using a constant concentration of protein. K A measurements were carried out in a methanol-formic acid solution. 5,11,17,23-tetra-Sulphonato-calix[4]arene (1a) and 25-mono-(2-aminoethoxy)-5,11,17,23-tetra-Sulphonato-calix[4]arene (1d) interact strongly with BSA showing 3 non-equivalent binding sites with K A1 = 7.
Journal of Inclusion Phenomena and Macrocyclic Chemistry, 2005
A spectrometric assay for the determination of concentration of para-sulphonato-calix[n]arenes an... more A spectrometric assay for the determination of concentration of para-sulphonato-calix[n]arenes and their derivatives has been developed using dimethylmethylene blue (DMMB) as a probe. Interaction with para-sulphonatocalix[n]arenes leads to a metachromatic shift in the spectrum of DMMB with appearance of a peak at 536 nm and diminution of the spectral intensity of the peaks at 594 and 649 nm. The method shows good linearity in the concentration range 0-6 lg/ml for para-sulphonato-calix[n]arenes.
International Journal of Heat and Fluid Flow, 2013
A numerical investigation of the behaviour of a cavitation pocket developing along a Venturi geom... more A numerical investigation of the behaviour of a cavitation pocket developing along a Venturi geometry has been performed using a compressible one-fluid hybrid RANS/LES solver. The interplay between turbulence and cavitation regarding the unsteadiness and structure of the flow is complex and not well understood. This constitutes a determinant point to accurately simulate the dynamic of sheet cavities. Various turbulent approaches are tested: a new Scale-Adaptive model and the Detached Eddy Simulation. 2D and 3D simulations are compared with the experimental data. An oblique mode of the sheet is put in evidence.
Uploads
Papers by Eric Soares silva