39 research outputs found
Asymptotic behavior of solutions to perturbed superstable wave equations
The paper deals with initial-boundary value problems for the linear wave equation whose solutions stabilize to zero in a finite time. We prove that problems in this class remain exponentially stable in L2 as well as in C2 under small bounded perturbations of the wave operator. To show this for C2, we prove a smoothing result implying that the solutions to the perturbed problems become eventually C2-smooth for any H1 × L2-initial data.Peer Reviewe
Sheep rumen shotgun sequencing for biomass-degrading genes discovery.
Abstract: The lignocellulose present in the plant biomass, is a promising source of energy generation. However, the breakdown of plant biomass into simple sugars for bioethanol production is still inefficient and costly due to the recalcitrant nature of plant fiber. Sheep rumen microbiome is specialized in degradation of plant material, but most members of this complex community are non-cultivable in laboratory. Therefore, the search for new lignocellulolytic enzymes in microbial communities naturally evolved in the biomass degradation, in environments such as the rumen, using the exploration of the metagenome, is a promising strategy for the exploration of genes. In this context, this study aimed to obtain plant biomass-degrading genes, selected from the sheep rumen microorganisms. The rumen samples were collected from 6 fistulated animals (Ovis aries), divided into two groups and subjected to two diets: control and sugarcane bagasse, 60 days after the beginning of the experiment. To characterize biomass-degrading genes, the metagenomic DNA was extracted from the solid contents of rumen followed by sequencing in MiSeq Personal Sequencer platform (Illumina®). We analyzed, 4,68 gigabases of metagenomic total DNA from microbes adherent to plant fiber, using on the CLC Genomic Workbench v.5.5.1 platform (CLC Bio, Denmark). The assembled contigs that allowed identification of 27 putative partial carbohydrate-active enzymes (CAE) (NCBI-nr) representing a total of 11 lignocellulases, 13 amylases and 3 other putative CAE from animals fed with control diet and 106 putative partial CAE representing a total of 52 lignocellulases, 46 amylases and 8 other putative CAE from animals fed with diet amended with sugarcane bagasse. These data sets shows the sheep rumen microbiome as an untapped source of potential new fibrolytic enzymes. Using a diet amended with sugarcane bagasse increases the abundance of CAE and provide a substantially expanded catalog of genes participating in the deconstruction of plant biomas
Exploring the sheep rumen shotgun sequencing for funcional analysis and lignocellulolitic enzyme discovery.
The rumen harbors complex microbial communities which participate in an efficient process to digest plant biomass. This ecosytem represents an untapped source of hydrolytic enzymes with potential application for second?generation biofuel production from lignocellulosic biomass. The search for new lignocellulolytic enzymes in microbial communities naturally evolved in the biomass degradation, in environments such as the rumen, using the exploration of the metagenome, is a promising strategy for the exploration of genes. In this context, this study aimed to describe the functions and explores the potential for lignocellulolitic enzyme in the sheep rumen microbiome. The rumen samples were collected from 6 fistulated animals (Ovis aries), divided into two groups and subjected to two diets: control and sugarcane bagasse, 60 days after the beginning of the experiment. Metagenomic DNA was extracted from the solid rumen contents and sequencing was performed in MiSeq Personal Sequencer platform (Illumina®). We analyzed, 4,68 GB of metagenomic DNA from microbes adherent to plant fiber using MGRAST metagenomics analysis server. The functional annotation was performed at MG?RAST for the total functional profile using the KEGG orthology level 2. The shotgun metagenomic reads of all animals samples was assigned to putative lignocellulolitic enzymes when considering nine protein databases at MG?RAST. The predictive functional profiling of the sheep rumen microbiome revealed that amino acid and carbohydrate metabolism, translation, DNA replication and repair, and membrane transport are dominant functions in the rumen microbiome. This functional pattern was similar across all animals. As expected, carbohydrate metabolism was highly represented in our data set, supporting the importance of the rumen microbiome for fiber degradation. Reads classification using nine databases resulted in 22 lignocellulases. For instance, the TrEMBL representing 76,77% out of a total 933639 protein abundance, followed by SwissProt representing 39,95 %, Seed 20,71%, PATRIC 5,92%, IMG 3,63%, KEEG 3,44%, GenBank 3,13%, RefSeq 3,09%, eggnog 1,48%. Based on Cazy search for glycosyl hydrolase (GH) families, more than 50 GH families were detected . The most abundant enzymes were ??glucosidase (GH1; GH30), Endo?1,4???xylanase (GH5; GH10; GH51) , ??N?arabinofuranosidase (GH7; GH51; GH54), ??galactosidase( GH27; GH31; GH36), Acetylesterase, Cellulase (GH5; GH9, GH7), Cellobiose phosphorylase (GH94), ??mannosidase(GH2; GH5), ??galactosidase(GH1; GH2; GH35). This results showing the sheep rumen microbiome as a promising source of new fibrolytic enzymes
Heart rate variability and cortisol levels in school-age children with different cognitive tests
Background. An urgent task of age-related physiology is to study the functional state of the body of school-age children in cognitive activity due to the large academic load and the use of information and computer technologies in the educational process to identify the characteristics of the reactivity of the body of students when performing cognitive load of various types, including on electronic devices, is necessary for the organization of the school educational environment.The aim. To assess the nature of vegetative, cardiovascular and hormonal reactivity in cognitive load of various types in school-age children.Materials and methods. By methods of heart rate variability analysis, electrocardiography, tonometry and enzyme immunoassay of cortisol in saliva, 117 school-age children were examined while performing cognitive load of various types.Results. There is a change in heart rate variability indicators while performing cognitive load. Oral counting causes an increase in sympathetic influences on the heart rate with a decrease in parasympathetic activity, as well as a shift in the vagosympathetic balance. Operation on the electronic devices causes a decrease in the total power density of the spectrum and an increase in the index of low-frequency and highfrequency vibrations ratio due to a decrease in parasympathetic activity. Two types of reaction were revealed: type I – an increase in the concentration of cortisol in saliva, an increase in sympathetic effects on Heart rate with a simultaneous decrease in parasympathetic activity (counting), a decrease in the total power of the spectrum density (laptop), a decrease in parasympathetic activity (tablet). Type II – a decrease in hormone levels and a decrease in very low-frequency vibrations and parasympathetic activity, regardless of the type of load presentedConclusion. The results obtained indicate that the nature of the reactivity of heart rate indicators and the stress hormone cortisol in students depends not so much on which electronic device it is performed on, but on the type of cognitive load
Measurements of CFTR-Mediated Cl- Secretion in Human Rectal Biopsies Constitute a Robust Biomarker for Cystic Fibrosis Diagnosis and Prognosis
BACKGROUND: Cystic Fibrosis (CF) is caused by ∼1,900 mutations in the CF transmembrane conductance regulator (CFTR) gene encoding for a cAMP-regulated chloride (Cl(-)) channel expressed in several epithelia. Clinical features are dominated by respiratory symptoms, but there is variable organ involvement thus causing diagnostic dilemmas, especially for non-classic cases.
METHODOLOGY/PRINCIPAL FINDINGS: To further establish measurement of CFTR function as a sensitive and robust biomarker for diagnosis and prognosis of CF, we herein assessed cholinergic and cAMP-CFTR-mediated Cl(-) secretion in 524 freshly excised rectal biopsies from 118 individuals, including patients with confirmed CF clinical diagnosis (n=51), individuals with clinical CF suspicion (n=49) and age-matched non-CF controls (n=18). Conclusive measurements were obtained for 96% of cases. Patients with "Classic CF", presenting earlier onset of symptoms, pancreatic insufficiency, severe lung disease and low Shwachman-Kulczycki scores were found to lack CFTR-mediated Cl(-) secretion (<5%). Individuals with milder CF disease presented residual CFTR-mediated Cl(-) secretion (10-57%) and non-CF controls show CFTR-mediated Cl(-) secretion ≥ 30-35% and data evidenced good correlations with various clinical parameters. Finally, comparison of these values with those in "CF suspicion" individuals allowed to confirm CF in 16/49 individuals (33%) and exclude it in 28/49 (57%). Statistical discriminant analyses showed that colonic measurements of CFTR-mediated Cl(-) secretion are the best discriminator among Classic/Non-Classic CF and non-CF groups.
CONCLUSIONS/SIGNIFICANCE: Determination of CFTR-mediated Cl(-) secretion in rectal biopsies is demonstrated here to be a sensitive, reproducible and robust predictive biomarker for the diagnosis and prognosis of CF. The method also has very high potential for (pre-)clinical trials of CFTR-modulator therapies.This work was supported by grants TargetScreen2 (EU/FP6/LSH/2005/037365), PIC/IC/83103/2007; PTDC/MAT/118335/2010; PEstOE/BIA/UI4046/2011
(to BioFIG) and PEstOE/MAT/UI0006/2011 (to CEAUL) from FCT (Portugal); and FAPESP (SPRF, Brazil), CNPq (40.8924/2006/3, Brazil) and Mukoviszidose e.V. S02/10
(Germany). MS and IU are recipients of SFRH/BD/35936/2007 and SFRH/BD/69180/2010 PhD fellowships (FCT, Portugal), respectively. The funders had no role in
study design, data collection and analysis, decision to publish, or preparation of the manuscript
Isolation, Production And Culture Of Primary Epithelial Cells From Patient's Airways For The Testing Of New Drugs To Cystic Fibrosis Treatment
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Calcium-activated and apoptotic phospholipid scrambling induced by Ano6 can occur independently of Ano6 ion currents
Immune cells and platelets maintain plasma membrane phospholipid asymmetry. Upon activation, this asymmetry is disrupted by phospholipid scrambling (PS), which is a major step during activation of immune cells, hemostasis and apoptosis. Anoctamin 6 (Ano6; TMEM16F) causes chloride (Cl(−)) and cation currents and is required for Ca(2+)-dependent PS. It is defective in blood cells from patients with Scott syndrome, a rare bleeding disorder. We examined if Cl(−) currents and PS are related, whether both processes are Ca(2+) dependent, and whether Ca(2+)-independent scrambling during intrinsic and extrinsic apoptosis is controlled by Ano6. Ca(2+) increase by ionomycin activated Ano6 Cl(−) currents and PS in normal lymphocytes, but not in B-lymphocytes from two different patients with Scott syndrome. Fas ligand (FasL) did not increase intracellular Ca(2+), but activated Cl(−) currents in normal but not in Scott lymphocytes. Whole-cell currents were inhibited by Cl(−) channel blockers and by siRNA knockdown of Ano6. In contrast, intrinsic mitochondrial apoptosis by ABT-737 did not induce Cl(−) currents in lymphocytes. PS was not inhibited by blockers of Ano6 or removal of Cl(−) ions. Remarkably, Ca(2+)-independent scrambling due to extrinsic (FasL) or intrinsic (ABT-737) apoptosis was unchanged in Scott cells. We conclude that: (i) Ano6 Cl(−) currents are activated by increase in cytosolic Ca(2+), or Ca(2+) independent by stimulation of Fas receptors; (ii) Ca(2+)-dependent PS induced by Ano6 does not require Cl(−) currents; (iii) Ca(2+)-independent PS does not require Ano6; (iv) Ano6 is necessary for Ca(2+)-dependent PS, but not by increasing intracellular Ca(2+)