52,040 research outputs found

    Application of lactic acid bacteria for the biopreservation of meat products: A systematic review

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    .The increasing concern of consumers about food quality and safety and their rejection of chemical additives has promoted the breakthrough of the biopreservation field and the development of studies on the use of beneficial bacteria and their metabolites as potential natural antimicrobials for shelf life extension and enhanced food safety. Control of foodborne pathogens in meat and meat products represents a serious challenge for the food industry which can be addressed through the intelligent use of bio-compounds or biopreservatives. This article aims to systematically review the available knowledge about biological strategies based on the use of lactic acid bacteria to control the proliferation of undesirable microorganisms in different meat products. The outcome of the literature search evidenced the potential of several strains of lactic acid bacteria and their purified or semi-purified antimicrobial metabolites as biopreservatives in meat products for achieving longer shelf life or inhibiting spoilage and pathogenic bacteria, especially when combined with other technologies to achieve a synergistic effect.S

    Study on the concordance between different SNP‚Äźgenotyping platforms in sheep

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    .Different SNP genotyping technologies are commonly used in multiple studies to perform QTL detection, genotype imputation, and genomic predictions. Therefore, genotyping errors cannot be ignored, as they can reduce the accuracy of different procedures applied in genomic selection, such as genomic imputation, genomic predictions, and false-positive results in genome-wide association studies. Currently, whole-genome resequencing (WGR) also offers the potential for variant calling analysis and high-throughput genotyping. WGR might overshadow array-based genotyping technologies due to the larger amount and precision of the genomic information provided; however, its comparatively higher price per individual still limits its use in larger populations. Thus, the objective of this work was to evaluate the accuracy of the two most popular SNP-chip technologies, namely, Affymetrix and Illumina, for high-throughput genotyping in sheep considering high-coverage WGR datasets as references. Analyses were performed using two reference sheep genome assemblies, the popular Oar_v3.1 reference genome and the latest available version Oar_rambouillet_v1.0. Our results demonstrate that the genotypes from both platforms are suggested to have high concordance rates with the genotypes determined from reference WGR datasets (96.59% and 99.51% for Affymetrix and Illumina technologies, respectively). The concordance results provided in the current study can pinpoint low reproducible markers across multiple platforms used for sheep genotyping data. Comparing results using two reference genome assemblies also informs how genome assembly quality can influence genotype concordance rates among different genotyping platforms. Moreover, we describe an efficient pipeline to test the reliability of markers included in sheep SNP-chip panels against WGR datasets available on public databases. This pipeline may be helpful for discarding low-reliability markers before exploiting genomic information for gene mapping analyses or genomic predictionS

    Interactive Sonic Environments: Sonic artwork via gameplay experience

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    The purpose of this study is to investigate the use of video-game technology in the design and implementation of interactive sonic centric artworks, the purpose of which is to create and contribute to the discourse and understanding of its effectiveness in electro-acoustic composition highlighting the creative process. Key research questions include: How can the language of electro-acoustic music be placed in a new framework derived from videogame aesthetics and technology? What new creative processes need to be considered when using this medium? Moreover, what aspects of 'play' should be considered when designing the systems? The findings of this study assert that composers and sonic art practitioners need little or no coding knowledge to create exciting applications and the myriad of options available to the composer when using video-game technology is limited only by imagination. Through a cyclic process of planning, building, testing and playing these applications the project revealed advantages and unique sonic opportunities in comparison to other sonic art installations. A portfolio of selected original compositions, both fixed and open are presented by the author to complement this study. The commentary serves to place the work in context with other practitioners in the field and to provide compositional approaches that have been taken

    Bioinformatic characterization of a triacylglycerol lipase produced by Aspergillus flavus isolated from the decaying seed of Cucumeropsis mannii

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    Lipases are enzymes of industrial importance responsible for the hydrolysis of ester bonds of triglycerides. A lipolytic fungus was isolated and subsequently identified based on the ITS sequence analysis as putative Aspergillus flavus with accession number LC424503. The gene coding for extracellular triacylglycerol lipase was isolated from Aspergillus flavus species, sequenced, and characterised using bioinformatics tools. An open reading frame of 420 amino acid sequence was obtained and designated as Aspergillus flavus lipase (AFL) sequence. Alignment of the amino acid sequence with other lipases revealed the presence GHSLG sequence which is the lipase consensus sequence Gly-X1-Ser-X2-Gly indicating that it a classical lipase. A catalytic active site lid domain composed of TYITDTIIDLS amino acids sequence was also revealed. This lid protects the active site, control the catalytic activity and substrate selectivity in lipases. The 3-Dimensional structural model shared 34.08% sequence identity with a lipase from Yarrowia lipolytica covering 272 amino acid residues of the template model. A search of the lipase engineering database using AFL sequence revealed that it belongs to the class GX-lipase, superfamily abH23 and homologous family abH23.02, molecular weight and isoelectric point values of 46.95‚ÄČKDa and 5.7, respectively. N-glycosylation sites were predicted at residues 164, 236 and 333, with potentials of 0.7250, 0.7037 and 0.7048, respectively. O-glycosylation sites were predicted at residues 355, 358, 360 and 366. A signal sequence of 37 amino acids was revealed at the N-terminal of the polypeptide. This is a short peptide sequence that marks a protein for transport across the cell membrane and indicates that AFL is an extracellular lipase. The findings on the structural and molecular properties of Aspergillus flavus lipase in this work will be crucial in future studies aiming at engineering the enzyme for biotechnology applications

    Ionic Liquids on Oxide Surfaces

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    Ionic liquids supported on oxide surfaces are being investigated for numerous applications including catalysis, batteries, capacitors, transistors, lubricants, solar cells, corrosion inhibitors, nanoparticle synthesis and biomedical applications. The study of ionic liquids with oxide surfaces presents challenges both experimentally and computationally. The interaction between ionic liquids and oxide surfaces can be rather complex, with defects in the oxide surface playing a key role in the adsorption behaviour and resulting electronic properties. The choice of the cation/anion pair is also important and can influence molecular ordering and electronic properties at the interface. These controllable interfacial behaviours make ionic liquid/oxide systems desirable for a number of different technological applications as well as being utilised for nanoparticle synthesis. This topical review aims to bring together recent experimental and theoretical work on the interaction of ionic liquids with oxide surfaces, including TiO2, ZnO, Al2O3, SnO2 and transition metal oxides. It focusses on the behaviour of ionic liquids at model single crystal surfaces, the interaction between ionic liquids and nanoparticulate oxides, and their performance in prototype devices

    The Caribbean Syzygy: a study of the novels of Edgar Mittelholzer and Wilson Harris

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    The problem of racial inheritance - the "search for identity" - is a recurring theme in the criticism of Caribbean literature. It is a pre-occupation with Caribbean writers, affecting both subject matter and literary quality, as FM. Birbalsingh, for example, has shown with reference to the novels of John Hearne and E,R. Braithwaite (Caribbean quarterly Vols. 14, December 1968 and 16, March 1970). This study of the work of Edgar Mittelholzer and Wilson Harris will attempt to show that there are important areas still to be explored relating Caribbean literature to its complex racial and cultural background. Both Mittelholzer and Harris deserve close, critical study in their own right; but a parallel examination reveals similarities and differences which bring into sharper focus wider concerns of Caribbean literature. The two important directions of West Indian writing are more clearly seen: the one, pioneered by Mittelholzer, in which the writer looks outward towards a "parent" culture, and the other looking inward, seeking in its own, complex inheritance the raw material for new and original growth. Mittelholzer and Harris are both Guyanese of mixed racial stock, both deeply concerned with the psychological effects of this mixture, and both writers have a profound awareness of the Guyanese historical and cultural heritage. They also share a deep feeling for the Guyenese landscape which appears in their work as a brooding presence affecting radically -the lives of those who live within i-t. Mittelholzer's attitude to his mixed racial and cultural origins, however, produces in his work a schizophrenic Imbalance while Harris, by accepting racial and cultural complexity as a starting-point, initiates a uniquely creative and experimental art. Mittelholzer, in his approach to history, human character eM landscape, remains a vi "coastal" writer never really concerned (as Harris is) with. the deeper significance of the "Interior" and all that this implies, both in a geographical and psychological sense. The fact that Mittelbolzer's work reflects a psychological imbalance induced by a pre-occupation with racial identity has been demonstrated by Denis Williams in the 1968 Mittelholzer Lectures, and by Joyce Sparer in a series of articles in the Guyana Graphic. Mittelholzer's awareness of this imbalance, however, and his attempt to come to terms with it in his art remain to be examined and documented, as does Harris's attempt to create am "associative" art aimed at healing the breach in the individual consciousness of Caribbean Man. The aim of this study is to demonstrate that Mitteholzer and. Harris, although antithetical in impact and style (each representing an approach to fiction directly opposed to the other) are, in fact, the opposite elements of a dichotomy. Their work illustrates the negative and positive aspects of the racial and cultural schizophrenia of the Caribbean, for both writers in their different ways are preoccupied with (and therefore have embodied in their work) the juxtaposition and, contrasting of apparently irreconcilable emotional and intellectual qualities - the Caribbean Syzygy

    In search of 'The people of La Manche': A comparative study of funerary practices in the Transmanche region during the late Neolithic and Early Bronze Age (250BC-1500BC)

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    This research project sets out to discover whether archaeological evidence dating between 2500 BC - 1500 BC from supposed funerary contexts in Kent, flanders and north-eastern Transmanche France is sufficient to make valid comparisons between social and cultural structures on either side of the short-sea Channel region. Evidence from the beginning of the period primarily comes in the form of the widespread Beaker phenomenon. Chapter 5 shows that this class of data is abundant in Kent but quite sparse in the Continental zones - most probably because it has not survived well. This problem also affects the human depositional evidence catalogued in Chapter 6, particularly in Fanders but also in north-eastern Transmanche France. This constricts comparative analysis, however, the abundant data from Kent means that general trends are still discernible. The quality and volume of data relating to the distribution, location, morphology and use of circular monuments in all three zones is far better - as demonstrated in Chapter 7 -mostly due to extensive aerial surveying over several decades. When the datasets are taken as a whole, it becomes possible to successfully apply various forms of comparative analyses. Most remarkably, this has revealed that some monuments apparently have encoded within them a sophisticated and potentially symbolically charged geometric shape. This, along with other less contentious evidence, demonstrates a level of conformity that strongly suggests a stratum of cultural homogeneity existed throughout the Transmanche region during the period 2500 BC - 1500 BC. The fact that such changes as are apparent seem to have developed simultaneously in each of the zones adds additional weight to the theory that contact throughout the Transmanche region was endemic. Even so, it may not have been continuous; there may actually have been times of relative isolation - the data is simply too course to eliminate such a possibility

    Electromethanogenesis at medium-low temperatures: Impact on performance and sources of variability

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    .In this study we aimed to understand the impact of medium‚Äďlow temperatures on the two main steps that usually comprise the electromethanogenesis (EM) process: electrothrophic hydrogenesis and hydrogenothrophic methanogenesis. Results revealed that pure CO2 could effectively be converted into a high-purity biogas (‚ąľ90:10 CH4/CO2) at 30 ¬įC. However, when temperature was reduced to 15 ¬įC, methane richness greatly decreased (‚ąľ40:60 CH4/CO2). This deterioration in performance was mostly attributed to a decline in methanogenic activity (represented mainly by Methanobacterium and Methanobrevibacter). In contrast, the hydrogenic activity (mostly Desulfomicrobium) did not suffer any significant decay. Results also seemed to indicate that methanogenesis, rather than hydrogenesis, is the main source of variability in EM. Increasing the temperature again to 30 ¬įC restored previous performance, which highlights the resilience of EM to wide temperature fluctuations (from 30 to 15 and back 30 ¬įC).S

    Elasticidad de membrana plasmática de levaduras mediante estudios de retracción de Nanotubo

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    27 h. figuras; tabls.; ilus. Abstract en espa√Īol e ingl√©s. Contiene Referencia Bibliogr√°fica.Las membranas biol√≥gicas constituyen la estructura celular m√°s com√ļn en la materia viva, pudiendo ser consideradas como un ejemplo de alta tecnolog√≠a natural de microencapsulaci√≥n. Las membranas se comportan como barreras mec√°nicas semipermeables, regulando el tr√°nsito y la se√Īalizaci√≥n de los compartimentos celulares con el exterior. A su vez, son extremadamente din√°micas tanto de manera global como a peque√Īa escala espacial. Las interacciones de los l√≠pidos entre s√≠ y con otras mol√©culas presentes en las membranas (principalmente prote√≠nas) son determinantes para muchas funciones, como la se√Īalizaci√≥n, los procesos de fusi√≥n y fisi√≥n o la adhesi√≥n celular. La forma f√≠sica de una estructura membranosa est√° determinada b√°sicamente por su grado de curvatura intr√≠nseca. De igual manera, esta propiedad evidencia la tendencia que tienen los l√≠pidos a formar fases no lamelares. La disposici√≥n de los l√≠pidos en la bicapa est√° directamente relacionada con su forma intr√≠nseca o geom√©trica, que tambi√©n condiciona el modo en que estas mol√©culas se empaquetan e interaccionan entre s√≠. En este trabajo de tesina se puso foco en la capacidad que tiene la membrana plasm√°tica de cambiar localmente su curvatura. Para realizar estos estudios, deformamos la membrana plasm√°tica localmente, generando tubos de membrana de di√°metro nanom√©trico mediante el empleo de pinzas √≥pticas. El trabajo se realiz√≥ sobre membranas de levaduras Saccharomyces cerevisiae de la cepa BY4741. Estudios previos han demostrado que cuando una bicapa lip√≠dica es sometida a un cambio local de curvatura presenta un comportamiento el√°stico, mientras que las membranas celulares de mam√≠feros son marcadamente viscoel√°sticas. Por otro lado, no se han reportado estudios de deformaciones locales de curvatura en membranas de organismos de otros reinos, que no contienen colesterol sino otros esteroles u hopanoides. Mediante estos experimentos se pretendi√≥ poner a punto la metodolog√≠a a fin de estudiar c√≥mo es la energ√©tica de deformaci√≥n fuera del plano de membrana plasm√°tica de levaduras S. cerevisiae cepa BY4741, la cual contiene un alto porcentaje del esterol ergosterol, en comparaci√≥n con el comportamiento ya conocido de membrana plasm√°tica de c√©lulas de mam√≠fero. En este trabajo se encontr√≥ que la relajaci√≥n de nanotubos de membranas plasm√°ticas de levaduras S. cerevisiae cepa BY4741 ocurre con tiempos caracter√≠sticos en el intervalo 0,02-0,5 s, y si promediamos todos los valores encontrados, obtenemos un valor promedio de 0,2 s ¬Ī 0,1 s. Este valor es similar a lo informado para eritrocitos, as√≠ como para c√©lulas tumorales cerebrales en humanos y c√©lulas de ovario de h√°mster chino. Hasta donde sabemos, no hay estudios de este tipo reportados en microorganismos eucariotas.Fil: Bischof, Andrea Alejandra. Universidad Nacional de C√≥rdoba. Facultad de Ciencias Exactas, F√≠sicas y Naturales; Argentina.Fil: Bischof, Andrea Alejandra. Universidad Nacional de C√≥rdoba. Facultad de Ciencias Qu√≠micas. Departamento de Qu√≠mica Biol√≥gica; Argentina.Fil: Bischof, Andrea Alejandra. Consejo Nacional de Investigaciones Cient√≠ficas y T√©cnicas. Centro de Investigaciones en Qu√≠mica Biol√≥gica de C√≥rdoba; Argentina
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