Effects of different tooth bleaching systems on the roughness and superficial morphology of enamel and a restorative composite resin

Objetivo: Avaliar as alterações de rugosidade e morfologia superficial do esmalte e da resina composta após diferentes técnicas de clareamento dental. Material e método: incisivos bovinos íntegros foram selecionados, sendo que cavidades padronizadas foram confeccionadas na face vestibular, as quais foram restauradas com resina composta. Os dentes foram distribuídos em grupos, de acordo com o tratamento proposto: G1-clareamento com peróxido de carbamida (PC) 10%; G2 - clareamento com peróxido de hidrogênio (PH) a 38%; G3- clareamento com PH a 38% associado à foto-ativação com LED. Para G1, o agente clareador foi aplicado por 8 horas diárias durante 21 dias. Para\ud G2 e G3, foram realizadas 3 sessões de clareamento, caracterizadas por 3 aplicações do gel clareador por 15 minutos, com intervalos de 7 dias entre as sessões, sendo que em G3 o gel clareador foi ativado com LED (470nm) por 6 minutos. As superfícies do esmalte e da resina composta foram avaliadas antes e após o procedimento clareador através de um rugosímetro e de um microscópio de força atômica. Resultados: Os resultados demonstraram diferença significante da rugosidade do esmalte antes e após o clareamento apenas para G1, em relação ao controle (Wilcoxon, p<0,05). Para a resina composta, nenhum dos grupos apresentou diferença estatística em relação ao controle (Mann-Whitney, p>0,05). Conclusão: O aumento da rugosidade do esmalte aconteceu apenas quando o clareamento foi realizado através da aplicação de um gel com 10% de PC. Nenhum dos procedimentos clareadores avaliados nesta pesquisa interferiram na rugosidade e morfologia da resina composta.CNPq (135181/2010-0; 30129/2010-1

Pathogenicity index, production of hemolysin and serogroup of samples of Escherichia coli isolated from commercial layng hens

Este estudo avaliou o índice de patogenicidade, a produção de hemolisina e a determinação de sorogrupos de cepas de Escherichia coli isoladas de fígado de aves de postura comercial com um dia de idade. Para este estudo, foram analisados 32 lotes, dos quais 15 foram positivos para o\ud isolamento de E. coli no fígado, totalizando vinte e quatro amostras. A patogenicidade dos isolados foi determinada por inoculação no saco aéreo de pintinhos e classificada como alta, intermediária, baixa ou não-patogênica. Os sorogrupos foram identificados utilizando um conjunto de antissoros anti-O (O1 a O180). A produção de hemolisina foi determinada por semeadura em ágar sangue de galinha (8%) e em placas de ágar sangue de carneiro (8%). Do total de amostras estudadas, 17 (70,83%) foram classificadas como não patogênica, 6 (25%) como de baixa patogenicidade e 1 (4,17%) de alta patogenicidade. Foram identificados 14 sorogrupos diferentes: O1, O2, O5, O8, O15, O18, O22, O36, O64, O70, O75, O115, O132, O141. Cinco cepas não tiveram o sorogrupo identificado. Com relação ao teste de produção de hemolisina, todas as cepas foram consideradas negativas, tanto para o teste realizado com ágar sangue de galinha quanto para o de carneiro. Os resultados obtidos neste estudo demonstram a importância de se identificar as cepas prevalentes de E. coli nas diferentes regiões produtoras, podendo ser utilizados em estudos epidemiológicos.This work evaluated the index of pathogenicity, the production of hemolysin and determination of serogroups in Escherichia coli strains isolated from liver of commercial laying hens with one day of age. Thirtytwo lots were analyzed, of which 15 were positive for the isolation of E. coli in the liver, for a total of 24 samples. The pathogenicity in one-day-old chicks was determined by inoculation in air sac and was classified as high, intermediate or low pathogenicity, or non-pathogenic. Serogroups were identified using a set of anti-O antisera (O1 to O180). The production of hemolysin was determined by plating on chicken blood agar (8%) and sheep blood agar (8%). Of the samples studied, 17 (70.83%) were classified as non-pathogenic, 6 (25%) as low pathogenicity and 1 (4.17%) as high pathogenicity. Fourteen different serogroups were identified: O1, O2, O5, O8, O15, O18, O22, O36, O64, O70, O75, O115, O132 and O141, while 5 samples were non-typable. Regarding the test for production of hemolysin, all strains were considered negative for both the test performed with chicken blood agar and that with sheep blood agar. The results of this study demonstrate the importance of identifying the prevalent strains of E. coli in different producing regions, as this information can be used in epidemiological studie

El aprendizaje escolar examinado desde la perspectiva del "Modelo 3P" de J. Biggs

El objetivo de este trabajo es presentar la contrastación de un modelo teórico de aprendizaje en el cual se postula que, de acuerdo con el Modelo 3P (Biggs, 1987a, 1993a), las variables de presagio inciden sobre las de producto, mediadas por las de proceso. El modelo ha sido analizado en base a las respuestas dadas por 561 estudiantes portugueses de Educación Secundaria, a un conjunto de instrumentos de medida (Inventario de Estilos de Pensamiento IEP, Batería de Pruebas de Razonamiento Diferencial BPRD, Cuestionario de Estrategias de Autorregulación del Aprendizaje, cuestiones para evaluar las concepciones de aprendizaje, metas escolares y un problema evaluado a partir de la taxonomía SOLO) y el rendimiento final del curso en diferentes áreas académicas. Los resultados confirman las hipótesis formuladas en el modelo postulado en esta investigación y son discutidas algunas consecuencias para la práctica educativa y para el desarrollo de los alumnos

Measurement of the top quark-pair production cross section with ATLAS in pp collisions at \sqrt{s}=7\TeV

A measurement of the production cross-section for top quark pairs(\ttbar) in $pp$ collisions at \sqrt{s}=7 \TeV is presented using data recorded with the ATLAS detector at the Large Hadron Collider. Events are selected in two different topologies: single lepton (electron $e$ or muon $\mu$) with large missing transverse energy and at least four jets, and dilepton ($ee$, $\mu\mu$ or $e\mu$) with large missing transverse energy and at least two jets. In a data sample of 2.9 pb-1, 37 candidate events are observed in the single-lepton topology and 9 events in the dilepton topology. The corresponding expected backgrounds from non-\ttbar Standard Model processes are estimated using data-driven methods and determined to be $12.2 \pm 3.9$ events and $2.5 \pm 0.6$ events, respectively. The kinematic properties of the selected events are consistent with SM \ttbar production. The inclusive top quark pair production cross-section is measured to be \sigmattbar=145 \pm 31 ^{+42}_{-27} pb where the first uncertainty is statistical and the second systematic. The measurement agrees with perturbative QCD calculations.Comment: 30 pages plus author list (50 pages total), 9 figures, 11 tables, CERN-PH number and final journal adde

Inclusive search for same-sign dilepton signatures in pp collisions at root s=7 TeV with the ATLAS detector

An inclusive search is presented for new physics in events with two isolated leptons (e or mu) having the same electric charge. The data are selected from events collected from p p collisions at root s = 7 TeV by the ATLAS detector and correspond to an integrated luminosity of 34 pb(-1). The spectra in dilepton invariant mass, missing transverse momentum and jet multiplicity are presented and compared to Standard Model predictions. In this event sample, no evidence is found for contributions beyond those of the Standard Model. Limits are set on the cross-section in a fiducial region for new sources of same-sign high-mass dilepton events in the ee, e mu and mu mu channels. Four models predicting same-sign dilepton signals are constrained: two descriptions of Majorana neutrinos, a cascade topology similar to supersymmetry or universal extra dimensions, and fourth generation d-type quarks. Assuming a new physics scale of 1 TeV, Majorana neutrinos produced by an effective operator V with masses below 460 GeV are excluded at 95% confidence level. A lower limit of 290 GeV is set at 95% confidence level on the mass of fourth generation d-type quarks

Measurement of inclusive two-particle angular correlations in pp collisions with the ATLAS detector at the LHC

We present a measurement of two-particle angular correlations in proton- proton collisions at s√=900 GeV and 7 TeV. The collision events were collected during 2009 and 2010 with the ATLAS detector at the Large Hadron Collider using a single-arm minimum bias trigger. Correlations are measured for charged particles produced in the kinematic range of transverse momentum p T  > 100 MeV and pseudorapidity |η| < 2.5. A complex structure in pseudorapidity and azimuth is observed at both collision energies. Results are compared to pythia 8 and herwig++ as well as to the AMBT2B, DW and Perugia 2011 tunes of pythia 6. The data are not satisfactorily described by any of these models

Standalone vertex finding in the ATLAS muon spectrometer

A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011

Ancient Migratory Events in the Middle East: New Clues from the Y-Chromosome Variation of Modern Iranians

Knowledge of high resolution Y-chromosome haplogroup diversification within Iran provides important geographic context regarding the spread and compartmentalization of male lineages in the Middle East and southwestern Asia. At present, the Iranian population is characterized by an extraordinary mix of different ethnic groups speaking a variety of Indo-Iranian, Semitic and Turkic languages. Despite these features, only few studies have investigated the multiethnic components of the Iranian gene pool. In this survey 938 Iranian male DNAs belonging to 15 ethnic groups from 14 Iranian provinces were analyzed for 84 Y-chromosome biallelic markers and 10 STRs. The results show an autochthonous but non-homogeneous ancient background mainly composed by J2a sub-clades with different external contributions. The phylogeography of the main haplogroups allowed identifying post-glacial and Neolithic expansions toward western Eurasia but also recent movements towards the Iranian region from western Eurasia (R1b-L23), Central Asia (Q-M25), Asia Minor (J2a-M92) and southern Mesopotamia (J1-Page08). In spite of the presence of important geographic barriers (Zagros and Alborz mountain ranges, and the Dasht-e Kavir and Dash-e Lut deserts) which may have limited gene flow, AMOVA analysis revealed that language, in addition to geography, has played an important role in shaping the nowadays Iranian gene pool. Overall, this study provides a portrait of the Y-chromosomal variation in Iran, useful for depicting a more comprehensive history of the peoples of this area as well as for reconstructing ancient migration routes. In addition, our results evidence the important role of the Iranian plateau as source and recipient of gene flow between culturally and genetically distinct population

The genomes of two key bumblebee species with primitive eusocial organization

Background: The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some species. High-quality genomic data will inform key aspects of bumblebee biology, including susceptibility to implicated population viability threats. Results: We report the high quality draft genome sequences of Bombus terrestris and Bombus impatiens, two ecologically dominant bumblebees and widely utilized study species. Comparing these new genomes to those of the highly eusocial honeybee Apis mellifera and other Hymenoptera, we identify deeply conserved similarities, as well as novelties key to the biology of these organisms. Some honeybee genome features thought to underpin advanced eusociality are also present in bumblebees, indicating an earlier evolution in the bee lineage. Xenobiotic detoxification and immune genes are similarly depauperate in bumblebees and honeybees, and multiple categories of genes linked to social organization, including development and behavior, show high conservation. Key differences identified include a bias in bumblebee chemoreception towards gustation from olfaction, and striking differences in microRNAs, potentially responsible for gene regulation underlying social and other traits. Conclusions: These two bumblebee genomes provide a foundation for post-genomic research on these key pollinators and insect societies. Overall, gene repertoires suggest that the route to advanced eusociality in bees was mediated by many small changes in many genes and processes, and not by notable expansion or depauperation