552 research outputs found

    Parameters of oxidative stress in saliva from patients with aggressive and chronic periodontitis

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    Objectives: Free radicals play an important role in the onset and progression of many diseases. The aim ofthis study was to investigate the contribution of oxidative stress in the pathology of aggressive (AgP) andchronic (CP) periodontitis and its relation with the clinical periodontal status.Methods: Eighty subjects were divided into two groups: 20 patients with AgP and 20 patients with CP withtheir 20 corresponding matched controls, based on clinical attachment loss (CAL), probing pocket depth(PPD), and bleeding on probing (BOP). Saliva reactive oxygen species (ROS), lipid peroxidation, and nonenzymaticantioxidant defences were measured by luminol-dependent chemiluminescence assay, asthiobarbituric acid-reactive substances (TBARs) and total radical-trapping antioxidant potential (TRAP),respectively. Pearson?s correlation and multivariate analysis were used to determine the relationshipbetween ROS and TBARs and the clinical parameters.Results: ROS and TBARs were increased in AgP while TRAP was decreased, comparing with CP. In AgP, astrong and positive correlation was observed between ROS and TBARs and they were closely associatedwith CAL and PPD.Discussion: In AgP, but not in CP, oxidative stress is a high contributor to periodontal pathology and it isclosely associated with the clinical periodontal status.Fil: Acquier, Andrea Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: de Couto Pita, Alejandra Karina. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Farmacología; ArgentinaFil: Busch, Lucila. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Farmacología; ArgentinaFil: Sanchez, Gabriel A.. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Biofísica; Argentin

    Sensorische Akzeptanz ökologischer Lebensmittel bei Kindern im Alter von 2 bis 7 Jahren - Testmöglichkeiten, Einflussfaktoren und Perspektiven

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    In der vorliegenden Studie ‚Äě Sensorische Akzeptanz √∂kologischer Lebensmittel bei Kindern im Alter von 2 bis 7 Jahren - Testm√∂glichkeiten, Einflussfaktoren und Perspektiven‚Äú wurden √ľber zwei Jahre Pr√§ferenz- und Akzeptanzpr√ľfungen mit 138 Kindern durchgef√ľhrt. Grundlegendes Ziel war die Untersuchung der sensorischen Akzeptanz von √∂kologischen Lebensmitteln. Pr√§ferenzen sollten ermittelt und im Zusammenhang mit potentiellen sensorischen Pr√§gungen durch die Ern√§hrung im 1. Lebensjahr betrachtet werden. √Ėkologische und konventionelle Lebensmittel wurden verkostet. Frageb√∂gen lieferten Informationen √ľber das aktuelle Ern√§hrungsverhalten. Erg√§nzend wurden die Lebensmittel von geschulten Pr√ľfern sensorisch beurteilt. Die Auswertung erfolgte unter Einbezug von Ern√§hrungsprotokollen aus dem 1. Lebensjahr und den Folgejahren. Die einzelnen Lebensmittel wurden von den Kindern z. T. unterschiedlich stark bevorzugt, aber eine eindeutige Vorliebe f√ľr √∂kologisch oder konventionell angebaute Lebensmittel gab es nicht. Lebensmittel beider Anbauformen wurden gut akzeptiert. Ausschlaggebend f√ľr die Beliebtheit oder Bevorzugung schienen die aktuellen sensorischen Merkmalseigenschaften eines Lebensmittels zu sein. Lebensmittel, die weniger sauer schmeckten, wurden pr√§feriert. Das aktuelle Ern√§hrungsverhalten und die Ern√§hrungshistorie ab dem 2. Lebensjahr zeigten nur vereinzelnd Zusammenh√§nge mit den, in den Testsituationen ermittelten, Pr√§ferenzen. F√ľr den Verzehr selbst hergestellter Beikost im 1. Lebensjahr konnten einige, wenige Zusammenh√§nge mit den sensorischen Entscheidungen im Alter von 2-7 Jahren beschrieben werden. Die Stilldauer und die Muttermilchmengen hatten keinen Einfluss auf die sensorischen Entscheidungen im Kindesalter zu haben

    Factors driving rodent abundance in agricultural landscapes of Central Argentina

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    Los cambios en el uso de la tierra en la regi√≥n Pampeana han conducido a un aumento de pasturas y campos cultivados y a una disminuci√≥n de pastizales nativos, los cuales permanecen principalmente en los bordes de campos. En esta regi√≥n existe una tendencia al aumento en el tama√Īo de los campos, a la eliminaci√≥n de los bordes entre ellos y a un aumento en la proporci√≥n del √°rea cultivada con soja. Los bordes funcionan como corredores y refugio para la fauna nativa, por tanto, su reducci√≥n puede afectar a la abundancia de roedores, dependiendo de las afinidades de h√°bitat de cada especie. Nuestro objetivo fue evaluar el efecto del tama√Īo de los campos y de la disminuci√≥n en el √°rea relativa de los bordes. El estudio se realiz√≥ en la provincia de Buenos Aires, Argentina central. Se muestrearon 12 campos y sus bordes. La abundancia total de roedores y las de ambas especies de Calomys mostraron efectos negativos del tama√Īo de los campos. Calomys laucha fue m√°s abundante en los campos de cultivo de ma√≠z, mientras que la abundancia de Calomys musculinus en campos aument√≥ con la cobertura de malezas. A. azarae mostr√≥ fuerte selecci√≥n por los bordes. En resumen, los cambios en el paisaje agr√≠cola, con un aumento de las √°reas cultivadas a expensas de ambientes naturales y seminaturales afecta a las comunidades de roedores y este efecto puede trasladarse a otros niveles tr√≥ cos, debido a su papel como consumidores de plantas e insectos y como fuente de alimento para aves y mam√≠feros predadores.Changes in land use in the Pampean region have led to an increase in pastures and cultivated fields and a decrease in native grasslands, which mainly remain at borders of cultivated fields. In Buenos Aires province there is a trend to increase the size of fields, eliminating the edges between them, and to increase the proportion of area cultivated with soybean. Borders function as corridors and refuges for native fauna, so this reduction may affect rodent abundance, although this effect may vary according to the species habitat affinities. Our goal was to evaluate the effect of the size of fields and the decrease in the proportion of border habitats on the rodent community. The study was conducted in Buenos Aires Province, Central Argentina. Rodents were surveyed in 12 fields and their borders. Overall rodent density and both species of Calomys showed negative effects of field size on their abundance, while for A. azarae there were no significant effects. Calomys laucha was more abundant in maize crop- fields, and Calomys musculinus did not show an effect of habitat, but its abundance in crop- fields increased with weed cover. Akodon azarae showed a strong habitat selection for borders. In summary, changes in the agricultural landscape with an increase in cropland at the expense of natural and semi natural habitats affect rodent communities and this effect would have consequences through their trophic interactions, both as consumers of plant and insect species as well as food sources for mammalian and avian predators.Fil: Adduci, Luciana Beatriz. Consejo Nacional de Investigaciones Cient√≠ficas y T√©cnicas. Oficina de Coordinaci√≥n Administrativa Ciudad Universitaria. Instituto de Ecolog√≠a, Gen√©tica y Evoluci√≥n de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecolog√≠a, Gen√©tica y Evoluci√≥n de Buenos Aires; ArgentinaFil: Busch, Maria. Consejo Nacional de Investigaciones Cient√≠ficas y T√©cnicas. Oficina de Coordinaci√≥n Administrativa Ciudad Universitaria. Instituto de Ecolog√≠a, Gen√©tica y Evoluci√≥n de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecolog√≠a, Gen√©tica y Evoluci√≥n de Buenos Aires; ArgentinaFil: Leon, Vanina Andrea. Consejo Nacional de Investigaciones Cient√≠ficas y T√©cnicas. Oficina de Coordinaci√≥n Administrativa Ciudad Universitaria. Instituto de Ecolog√≠a, Gen√©tica y Evoluci√≥n de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecolog√≠a, Gen√©tica y Evoluci√≥n de Buenos Aires; ArgentinaFil: Fraschina, Jimena. Consejo Nacional de Investigaciones Cient√≠ficas y T√©cnicas. Oficina de Coordinaci√≥n Administrativa Ciudad Universitaria. Instituto de Ecolog√≠a, Gen√©tica y Evoluci√≥n de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecolog√≠a, Gen√©tica y Evoluci√≥n de Buenos Aires; Argentin

    Chloroflexi Dominate the Deep-Sea Golf Ball Sponges Craniella zetlandica and Craniella infrequens Throughout Different Life Stages

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    Deep-sea sponge grounds are underexplored ecosystems that provide numerous goods and services to the functioning of the deep-sea. This study assessed the prokaryotic diversity in embryos, recruits, and adults of Craniella zetlandica and Craniella infrequens, common and abundant representatives of deep-sea sponge grounds in the North Atlantic. Our results reveal that symbiont transmission in the two Craniella sponge species likely occurs vertically, as highly similar microbial consortia have been identified in adults, embryos, and recruits. Moreover, transmission electron microscopy revealed high abundances of sponge-associated microorganisms, among which Chloroflexi (SAR202) were identified as common representatives by amplicon sequencing and fluorescence in situ hybridization (FISH). Equal diversity metrices, a similar overall prokaryotic community composition and a distinct dominance of the phylum Chloroflexi within all life stages are the key findings of our analyses. Information such as presented here provide understanding on the recruitment of deep-sea sponge holobionts which is needed to develop integrated management tools of such vulnerable marine ecosystems

    Microscopic evidence of the connection between liquid-liquid transition and dynamical crossover in an ultraviscous metallic glass former

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    Liquid-liquid transitions are interesting to many researchers since they occur in systems as diverse as monoatomic liquids, multicomponent oxides, and metallic glass formers. In some cases, the crossover is accompanied by changes in the dynamical properties. By combining state-of-the-art synchrotron techniques, we followed the structure and atomic motion during quasistatic cooling of the Au49Cu26.9Si16.3Ag5.5Pd2.3 metallic glass former from the low-temperature supercooled liquid. With this thermal protocol, we were able to lower the glass transition temperature far enough to reveal a liquid-liquid crossover between two amorphous structures corresponding to two ultraviscous liquids with different kinetic behavior. This transition is in competition with vitrification, which occurs at conventional cooling rates, and is accompanied by structural changes not affecting the average density. Our results provide a direct connection between polyamorphism and dynamical crossover, and an alternative case to add to the highly debated topic on the low-temperature divergence of the dynamics in supercooled liquids.Peer ReviewedPostprint (published version

    Conectividad entre las subpoblaciones de rata noruega (Rattus norvegicus) que habitan granjas avícolas de Exaltación de la Cruz, Buenos Aires, Argentina

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    Despite of the substantial economic and human health problems produced by rodents of the genus Rattus almost nothing is known about its actual dispersal. In the present study we analyze the genetic subdivision of R. norvegicus inhabiting poultry farms of Buenos Aires, Argentina, and the relation between geographic and genetic distances by means of variation in microsatellite loci. We genotyped 40 rats captured between April-06 and June-07 from nine poultry farms distributed in an area of 110 km2 . No genetic subdivision was found among di erent poultry farms. This result supports the hypothesis of high connectivity between R. norvegicus inhabiting poultry farms in Buenos Aires. Because this species is a known host of diverse zoonosis as leptospirosis and trichinosis, our results point out that there is a great risk of transmission for distances lower than 12 km. Health control and preventive measures should therefore be applied simultaneously in all nearby poultry farms.A pesar de los problemas econ√≥micos y de salud producidos por roedores del g√©nero Rattus, se conoce muy poco sobre su dispersi√≥n efectiva. En el presente estudio analizamos la subdivisi√≥n gen√©tica de las subpoblaciones de R. norvegicus que habitan granjas av√≠colas de Buenos Aires, Argentina, y la relaci√≥n entre las distancias geogr√° cas y gen√©ticas por medio de la variabilidad en loci de microsat√©lites. Se genotiparon 40 ratas capturadas entre abril-06 y junio-07 en nueve granjas av√≠colas distribuidas dentro de un √°rea de 110 km2 . No se encontr√≥ subdivisi√≥n gen√©tica entre las diferentes granjas av√≠colas. Esto apoya la hip√≥tesis de alta conectividad entre R. norvegicus que habitan granjas av√≠colas en Buenos Aires. Debido a que R. norvegicus es un conocido hospedador de diversas zoonosis como leptospirosis y triquinosis, nuestros resultados indican que existe un gran riesgo de transmisi√≥n para distancias menores a 12 km. La medidas de control y prevenci√≥n sanitarias deber√≠an, por lo tanto, aplicarse en todas las granjas cercanas en forma simult√°nea.Fil: Gomez Villafa√Īe, Isabel Elisa. Consejo Nacional de Investigaciones Cient√≠ficas y T√©cnicas. Oficina de Coordinaci√≥n Administrativa Ciudad Universitaria. Instituto de Ecolog√≠a, Gen√©tica y Evoluci√≥n de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecolog√≠a, Gen√©tica y Evoluci√≥n de Buenos Aires; ArgentinaFil: Guzman, Noelia Veronica. Consejo Nacional de Investigaciones Cient√≠ficas y T√©cnicas. Oficina de Coordinaci√≥n Administrativa Ciudad Universitaria. Instituto de Ecolog√≠a, Gen√©tica y Evoluci√≥n de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecolog√≠a, Gen√©tica y Evoluci√≥n de Buenos Aires; ArgentinaFil: Ortiz, Natalia. Consejo Nacional de Investigaciones Cient√≠ficas y T√©cnicas. Centro Cient√≠fico Tecnol√≥gico Conicet - C√≥rdoba. Instituto de Diversidad y Ecolog√≠a Animal. Universidad Nacional de C√≥rdoba. Facultad de Ciencias Exactas F√≠sicas y Naturales. Instituto de Diversidad y Ecolog√≠a Animal; ArgentinaFil: Gonz√°lez Ittig, Ra√ļl Enrique. Consejo Nacional de Investigaciones Cient√≠ficas y T√©cnicas. Centro Cient√≠fico Tecnol√≥gico Conicet - C√≥rdoba. Instituto de Diversidad y Ecolog√≠a Animal. Universidad Nacional de C√≥rdoba. Facultad de Ciencias Exactas F√≠sicas y Naturales. Instituto de Diversidad y Ecolog√≠a Animal; Argentina. Universidad Nacional de C√≥rdoba. Facultad de Ciencias Exactas, F√≠sicas y Naturales. Departamento de Fisiolog√≠a. C√°tedra de Gen√©tica de Poblaciones y Evoluci√≥n; ArgentinaFil: Leon, Vanina Andrea. Consejo Nacional de Investigaciones Cient√≠ficas y T√©cnicas. Oficina de Coordinaci√≥n Administrativa Ciudad Universitaria. Instituto de Ecolog√≠a, Gen√©tica y Evoluci√≥n de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecolog√≠a, Gen√©tica y Evoluci√≥n de Buenos Aires; ArgentinaFil: Busch, Maria. Consejo Nacional de Investigaciones Cient√≠ficas y T√©cnicas. Oficina de Coordinaci√≥n Administrativa Ciudad Universitaria. Instituto de Ecolog√≠a, Gen√©tica y Evoluci√≥n de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecolog√≠a, Gen√©tica y Evoluci√≥n de Buenos Aires; Argentin

    Conservation of core complex subunits shaped the structure and function of photosystem I in the secondary endosymbiont alga Nannochloropsis gaditana

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    Photosystem I (PSI) is a pigment protein complex catalyzing the light-driven electron transport from plastocyanin to ferredoxin in oxygenic photosynthetic organisms. Several PSI subunits are highly conserved in cyanobacteria, algae and plants, whereas others are distributed differentially in the various organisms. Here we characterized the structural and functional properties of PSI purified from the heterokont alga Nannochloropsis gaditana, showing that it is organized as a supercomplex including a core complex and an outer antenna, as in plants and other eukaryotic algae. Differently from all known organisms, the N. gaditana PSI supercomplex contains five peripheral antenna proteins, identified by proteome analysis as type-R light-harvesting complexes (LHCr4-8). Two antenna subunits are bound in a conserved position, as in PSI in plants, whereas three additional antennae are associated with the core on the other side. This peculiar antenna association correlates with the presence of PsaF/J and the absence of PsaH, G and K in the N. gaditana genome and proteome. Excitation energy transfer in the supercomplex is highly efficient, leading to a very high trapping efficiency as observed in all other PSI eukaryotes, showing that although the supramolecular organization of PSI changed during evolution, fundamental functional properties such as trapping efficiency were maintained
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