oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2018 ( 5 )

2017 ( 11 )

2016 ( 12 )

2015 ( 330 )

Custom range...

Search Results: 1 - 10 of 4711 matches for " Laurent Bazinet "
All listed articles are free for downloading (OA Articles)
Page 1 /4711
Display every page Item
Ultrathin Sicopion Composite Cation-Exchange Membranes: Characteristics and Electrodialytic Performance following a Conditioning Procedure
Erik Ayala-Bribiesca,Mario Boucher,Laurent Bazinet
International Journal of Chemical Engineering , 2012, DOI: 10.1155/2012/932723
Abstract: The aim of this work was to investigate the properties of Sicopion membranes: an ultrathin (≈20?μm) composite cation-exchange membrane (CEM) made from sulphonated poly(ether-ether-ketone) (SPEEK) containing different levels of sulphonic-functionalized silica particles (SFSPs). Sicopion membranes were conditioned according to the French Normalization Association procedure, consisting in a series of acid and alkaline washes, and their electrodialytic characteristics were compared to an existent commercial food-grade membrane (CMX-SB). Electrical conductivity of Sicopion membranes was higher than that of CMX-SB membranes (9.92 versus 6.98?mS/cm), as well as their water content (34.0 versus 27.6%). As the SFSP level was reduced, the ion-exchange capacity (IEC) of Sicopion membranes increased. Concerning their electrodialytic performances, Sicopion membranes presented a lower demineralization rate than CMX-SB membranes (35.9 versus 45.5%), due to an OH? leakage through the pores created by dislodging the SFSP particles during the conditioning procedure. 1. Introduction Sicopion is a novel type of membranes made of a composite material combining sulphonic-functionalized silica particles (SFSP) and sulphonated poly(ether-ether-ketone) (SPEEK). In this composite material, the functionalization of silica particles is accomplished by covalently grafting sulphonic acid groups [1]. In the case of SPEEK, concentrated H2SO4 is used to sulphonate, also by covalent bonding, an aromatic chain of poly(ether-ether-ketone) (PEEK) [1, 2]. Once the organic and the inorganic phases prepared, they are mixed in specific proportions according to the application requirements. The resulting composite material is then prepared in a membrane form. Among the factors affecting the membrane properties there is the sulphonation degree of the components and the type and amount of SFSP used. A PEEK should be partially sulphonated to decrease its hydrophobicity and produce an ion-exchanging material, but high degrees of sulphonation are to be avoided, since the polymer would then become water soluble, which is the case of 100% SPEEK [1, 2]. The amount of SFSPs, as well as their size, determines the formation of a continuous hydrophilic phase and the mechanical properties of the material. A high content of inorganic particles (i.e., SFSP) produces higher membrane hydration and water retention capacity but, in contrast, yields a brittle membrane with lower tear resistance [1]. These materials impart to the membrane a highly functional ion-exchanging structure without inert fillers. At the
Inhibitory Effects of Commercial and Enriched Green Tea Extracts on the Growth of Brochothrix thermosphacta, Pseudomonas putida and Escherichia coli
Elodie Rozoy,Laurent Bazinet,Monica Araya-Farias,Anthony Guernec
Journal of Food Research (JFR) , 2012, DOI: 10.5539/jfr.v2n1p1
Abstract: The major catechin found in green tea, called epigallocatechin gallate (EGCG), have been reported to have antimicrobial properties. In this study, we examined in vitro the antimicrobial effects of a commercial green tea extract sold in a capsule form, and two prepared green tea extracts enriched in catechins against Brochothrix thermosphacta, Pseudomonsas putida and Escherichia coli which have been associated with meat spoilage. The antimicrobial activity of the different tea extracts was evaluated by Spot-On-Lawn and Well Diffusion assays and the Minimum Inhibitory Concentration (MIC) was also determined in Brain Heart Infusion broth. The three methods used showed an inhibition of Brochothrix thermosphacta, whereas the inhibition of Pseudomonas putida and Escherichia coli was only detected with the MIC assay. The determination of the MIC in broth culture appeared to be the most reliable method to determine the inhibitory activity of catechin compounds.
A comparative evaluation of sequence classification programs
Adam L Bazinet, Michael P Cummings
BMC Bioinformatics , 2012, DOI: 10.1186/1471-2105-13-92
Abstract: We divided the very large number of programs that have been released in recent years for solving the sequence classification problem into three main categories based on the general algorithm they use to compare a query sequence against a database of sequences. We also evaluated the performance of the leading programs in each category on data sets whose taxonomic and functional composition is known.We found significant variability in classification accuracy, precision, and resource consumption of sequence classification programs when used to analyze various metagenomics data sets. However, we observe some general trends and patterns that will be useful to researchers who use sequence classification programs.
Neurotransmitter Transporter-Like: A Male Germline-specific SLC6 Transporter Required for Drosophila Spermiogenesis
Nabanita Chatterjee,Janet Rollins,Anthony P. Mahowald,Christopher Bazinet
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0016275
Abstract: The SLC6 class of membrane transporters, known primarily as neurotransmitter transporters, is increasingly appreciated for its roles in nutritional uptake of amino acids and other developmentally specific functions. A Drosophila SLC6 gene, Neurotransmitter transporter-like (Ntl), is expressed only in the male germline. Mobilization of a transposon inserted near the 3′ end of the Ntl coding region yields male-sterile mutants defining a single complementation group. Germline transformation with Ntl cDNAs under control of male germline-specific control elements restores Ntl/Ntl homozygotes to normal fertility, indicating that Ntl is required only in the germ cells. In mutant males, sperm morphogenesis appears normal, with elongated, individualized and coiled spermiogenic cysts accumulating at the base of the testes. However, no sperm are transferred to the seminal vesicle. The level of polyglycylation of Ntl mutant sperm tubulin appears to be significantly lower than that of wild type controls. Glycine transporters are the most closely related SLC6 transporters to Ntl, suggesting that Ntl functions as a glycine transporter in developing sperm, where augmentation of the cytosolic pool of glycine may be required for the polyglycylation of the massive amounts of tubulin in the fly's giant sperm. The male-sterile phenotype of Ntl mutants may provide a powerful genetic system for studying the function of an SLC6 transporter family in a model organism.
Suppression of Autoimmune Retinal Inflammation by an Antiangiogenic Drug
Takeru Yoshimura, Ofra Benny, Lauren Bazinet, Robert J. D’Amato
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0066219
Abstract: Chronic and recurrent uveitis account for approximately 10% of legal blindness in the western world. Autoimmune uveitis is driven by activated CD4+ T cells that differentiate into effector T helper cells (Th1, Th2, and Th17) which release proinflammatory cytokines that damage the retina. In this study we investigated the effect of the methionine aminopeptidase 2 (MetAP2) inhibitor, Lodamin, on T cell activation and differentiation. MetAp2 is an enzyme which regulates cellular protein synthesis and is highly expressed in T cells. Lodamin was found to suppress T cell receptor (TCR) mediated T cell proliferation and reduced the production of Th1 and Th17 cells. Further, Lodamin suppressed overall inflammation in the mouse model of experimental autoimmune uveitis (EAU) by a six fold. This effect was attributed in part to a reduction in retinal proinflammatory cytokines, down regulation of MetAP2 expression in purified lymph node CD4+ T cells, and a general normalization of the systemic immune reaction.
Marine Biology: A Sub-Sample of a Vast Topic  [PDF]
Laurent Seuront
Open Journal of Marine Science (OJMS) , 2013, DOI: 10.4236/ojms.2013.32A001
Abstract:

Marine Biology: A Sub-Sample of a Vast Topic

Generalized Powers of Substitution with Pre-Function Operators  [PDF]
Laurent Poinsot
Applied Mathematics (AM) , 2013, DOI: 10.4236/am.2013.47A004
Abstract:

An operator on formal power series of the form S \"\" μS , where μ is an invertible power series, and σ is a series of the form t+\"\"(t2) is called a unipotent substitution with pre-function. Such operators, denoted by a pair (μ σ )  , form a group. The objective of this contribution is to show that it is possible to define a generalized powers for such operators, as for instance fractional powers \"\"σ for every\"\" .

The Mediating Role of the Sense of Relatedness and Task Cohesion in the Relation between Psychological Power Distance and Efficicency of a Working Team  [PDF]
Laurent Auzoult
Psychology (PSYCH) , 2013, DOI: 10.4236/psych.2013.410105
Abstract:

Understanding of the effectiveness of work-teams is a major issue in the business world, where they are expected to facilitate developing individual skills and increasing organizations’ efficiency. Eighty-three engineers working in teams have responded to a questionnaire devised to measure perceptual power distances, the sense of relatedness, cohesion measured by integration around the task, and teams’ effectiveness. Results reveal that “task cohesion” and sense of relatedness mediate the relationship between power distance and perceived effectiveness. These results are related with those observed in the context of the self-determination theory and presented in order to highlight their practical implications.

Selective remodeling of cardiolipin fatty acids in the aged rat heart
Ho-Joo Lee, Jana Mayette, Stanley I Rapoport, Richard P Bazinet
Lipids in Health and Disease , 2006, DOI: 10.1186/1476-511x-5-2
Abstract: The concentration (nmol/g) of linoleic acid was decreased in 24 month old rats (3965 ± 617, mean ± SD) vs 4 month old rats (5525 ± 656), while the concentrations of arachidonic and docosahexaenoic acid were increased in 24 month old rats (79 ± 9 vs 178 ± 27 and 104 ± 16 vs 307 ± 68 for arachidonic and docosahexaenoic acids, 4 months vs 24 months, respectively). Similar changes were not observed in ethanolamine glycerophospholipids or plasma unesterified fatty acids, suggesting specificity of these effects to cardiolipin.These results demonstrate that cardiolipin remodeling occurs with aging, specifically an increase in highly unsaturated fatty acids.Cardiolipin (1'- [1,2-diacyl-sn-glycero-3-phosphoryl]-3'- [1",2"-diacyl-sn-glycero-3"-phosphoryl]-sn-glycerol; 1,3-diphosphatidylglycerol) is a phospholipid found in particularly high concentrations in the heart. In mammalian cells, it is localized to the inner mitochondrial membrane [1] and is known for its unique and specific acyl structure. Cardiolipin, unlike other mammalian phospholipids, contains 4 stereospecifically numbered acyl groups. Heart cardiolipin is predominately acylated with linoleic acid [2]. The acyl specificity of cardiolipin is believed to occur via remodeling, as the enzymes responsible for its de novo synthesis are not acyl group specific [3,4].Despite being discovered a relatively long time ago [5], fairly little is known about the function of cardiolipin, especially in mammalian cells. Several excellent reviews have summarized the known biochemistry and functions of cardiolipin which is thought to regulate several mitochondrial proteins [6-9]. It also is known that cardiolipin acyl chains vary greatly by species [10-13] and tissue, and can be modified by diet [14-17]. However, the functional significance of these changes is not known. It is controversial whether the acyl-chain composition of cardiolipin is altered with ageing. Several studies have reported that heart and liver total cardiolipin
Can RNA-Seq Resolve the Rapid Radiation of Advanced Moths and Butterflies (Hexapoda: Lepidoptera: Apoditrysia)? An Exploratory Study
Adam L. Bazinet, Michael P. Cummings, Kim T. Mitter, Charles W. Mitter
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0082615
Abstract: Recent molecular phylogenetic studies of the insect order Lepidoptera have robustly resolved family-level divergences within most superfamilies, and most divergences among the relatively species-poor early-arising superfamilies. In sharp contrast, relationships among the superfamilies of more advanced moths and butterflies that comprise the mega-diverse clade Apoditrysia (ca. 145,000 spp.) remain mostly poorly supported. This uncertainty, in turn, limits our ability to discern the origins, ages and evolutionary consequences of traits hypothesized to promote the spectacular diversification of Apoditrysia. Low support along the apoditrysian “backbone” probably reflects rapid diversification. If so, it may be feasible to strengthen resolution by radically increasing the gene sample, but case studies have been few. We explored the potential of next-generation sequencing to conclusively resolve apoditrysian relationships. We used transcriptome RNA-Seq to generate 1579 putatively orthologous gene sequences across a broad sample of 40 apoditrysians plus four outgroups, to which we added two taxa from previously published data. Phylogenetic analysis of a 46-taxon, 741-gene matrix, resulting from a strict filter that eliminated ortholog groups containing any apparent paralogs, yielded dramatic overall increase in bootstrap support for deeper nodes within Apoditrysia as compared to results from previous and concurrent 19-gene analyses. High support was restricted mainly to the huge subclade Obtectomera broadly defined, in which 11 of 12 nodes subtending multiple superfamilies had bootstrap support of 100%. The strongly supported nodes showed little conflict with groupings from previous studies, and were little affected by changes in taxon sampling, suggesting that they reflect true signal rather than artifacts of massive gene sampling. In contrast, strong support was seen at only 2 of 11 deeper nodes among the “lower”, non-obtectomeran apoditrysians. These represent a much harder phylogenetic problem, for which one path to resolution might include further increase in gene sampling, together with improved orthology assignments.
Page 1 /4711
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.