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Search Results: 1 - 10 of 401130 matches for " M. Brammer "
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Macrophage Inflammatory Response to TiO2 Nanotube Surfaces  [PDF]
Sungho Jin, Lisa M. Chamberlain, Karla S. Brammer, Gary W. Johnston, Shu Chien
Journal of Biomaterials and Nanobiotechnology (JBNB) , 2011, DOI: 10.4236/jbnb.2011.23036
Abstract: It is well known that the native oxide layer on titanium (Ti) implants is responsible for its superior biocompatibility and tissue integration. Recent efforts have targeted titanium dioxide (TiO2) as a good candidate for surface modification at the nanoscale, leading to improved nanotextures for enhancing host integration properties. Here we explore the in vitro inflammatory response of macrophages to TiO2 nanotube surface structures with different diameters (30, 50, 70, and 100nm) created by a simple electrochemical anodization process. This work was designed to study the nanosize effect for controlling and optimizing inflammatory response to a Ti implant surface utilizing nanotechnology. Using intracellular staining and flow cytometry for detecting macrophage TNF cytokine expression, we have found that 70nm diameter nanotube surfaces have the bestadvantage in terms of diameter size by producing theweakest inflammatory response, compared to a commercially available Ti surface without oxide modification. We also present cell-freedata on free radical scavenging using the nanotube surfaces with different diameters to test the removal of nitric oxidefrom solution; again, our findings indicate that 70nm titanium dioxide nanotubes exhibit optimal removal of nitric oxide from solution, making them excellent candidates for use in medical devices that would benefit from decreased inflammatory response
Gene Expression: A Review on Methods for the Study of Defense-Related Gene Differential Expression in Plants  [PDF]
Alice Casassola, Sandra Patussi Brammer, Márcia Soares Chaves, José Ant?nio Martinelli, Magali Ferrari Grando, Norimar D’ávila Denardin
American Journal of Plant Sciences (AJPS) , 2013, DOI: 10.4236/ajps.2013.412A3008
Abstract:

The plant genes involved in cellular signaling and metabolism have not been fully identified, while the function(s) of many of those which have are as yet incompletely characterized. Gene expression analysis allows the identification of genes and the study of their relationship with cellular processes. There are several options available for studying gene expression, including the use of cDNA and microarray libraries and techniques such as suppression subtractive hybridization (SSH), differential display (DD), RNA fingerprinting by arbitrary primed PCR (RAP), expressed sequence tags (EST), serial analysis of gene expression (SAGE), representational difference analysis (RDA), cDNA-amplified fragment length polymorphism (cDNA-AFLP) and RNA sequencing (RNA-Seq). Focusing on defense-related processes in plants, we present a brief review and examples of each of these methodologies and their advantages and limitations regarding the study of plant gene expression.

Overturning the Case for Gravitational Powering in the Prototypical Cooling Lyman-alpha Nebula
Moire K. M. Prescott,Ivelina Momcheva,Gabriel B. Brammer,Johan P. U. Fynbo,Palle M?ller
Physics , 2015, DOI: 10.1088/0004-637X/802/1/32
Abstract: The Nilsson et al. (2006) Lyman-alpha nebula has often been cited as the most plausible example of a Lyman-alpha nebula powered by gravitational cooling. In this paper, we bring together new data from the Hubble Space Telescope and the Herschel Space Observatory as well as comparisons to recent theoretical simulations in order to revisit the questions of the local environment and most likely power source for the Lyman-alpha nebula. In contrast to previous results, we find that this Lyman-alpha nebula is associated with 6 nearby galaxies and an obscured AGN that is offset by $\sim$4"$\approx$30 kpc from the Lyman-alpha peak. The local region is overdense relative to the field, by a factor of $\sim$10, and at low surface brightness levels the Lyman-alpha emission appears to encircle the position of the obscured AGN, highly suggestive of a physical association. At the same time, we confirm that there is no compact continuum source located within $\sim$2-3"$\approx$15-23 kpc of the Lyman-alpha peak. Since the latest cold accretion simulations predict that the brightest Lyman-alpha emission will be coincident with a central growing galaxy, we conclude that this is actually a strong argument against, rather than for, the idea that the nebula is gravitationally-powered. While we may be seeing gas within cosmic filaments, this gas is primarily being lit up, not by gravitational energy, but due to illumination from a nearby buried AGN.
Identifica??o de fontes de resistência à ferrugem da folha do trigo em acessos de Aegilops tauschii
Almeida, ?ngela B.;Chaves, Márcia S.;Brammer, Sandra P.;Baggio, Maria Irene;
Fitopatologia Brasileira , 2007, DOI: 10.1590/S0100-41582007000400011
Abstract: in brazil, losses caused by wheat leaf rust (puccinia triticina) occur annually. the widespread incidence in the different producing areas varies in intensity, depending on climatic conditions, level of genetic resistance of the cultivars and efficacy of chemical control. the use of resistant cultivars is the most efficient control method, and the genes conferring resistance to leaf rust fungus are denominated lr. several of these genes have already been identified and mapped. some of them were mapped directly in hexaploid wheats, while others were initially found in related species, with lower ploidy level and later transferred to cultivated wheat. among related species, aegilops tauschii, the diploid species donor of the d genome of cultivated wheat, is indicated as an important source of resistance genes to leaf rust. the objective of this work was to evaluate the resistance of a. tauschii accessions from the active germplasm bank of embrapa trigo (bag - passo fundo, rs) to leaf rust, in order to incorporate this resistance in commercial varieties. the reaction to race spj-rs of puccinia triticina was evaluated in forty accessions of a. tauschii and 25% (10 accessions) were resistant. the data obtained in this study can help in choosing resistant accessions to be used as parents in breeding programs in order to increase resistance to the pathogen.
Parental selection of wheat lines based on phenotypic characterization and genetic diversity
Alice Casassola,Sandra Patussi Brammer,Márcia Soares Chaves,Paula Wieth?lter
Crop Breeding and Applied Biotechnology , 2013,
Abstract: Parental selection is an important step in breeding programs, and genetic variability increases the chances of obtaining variance in progenies. The objectives of this study were to phenotype 29 wheat genotypes and determine the genetic variability among them, in order to identify potential parental lines for breeding programs at Embrapa Wheat. For phenotyping, traits such as plant height, cycle and grains characteristics were assessed and the data were analyzed by the Euclidean distance. The genetic distance was estimated using 97 microsatellite molecular markers and the data were analyzed by Nei72 coefficient. The average distance observed for phenotyping was 10.1, and the genetic distance was 31 %. SSR markers were efficient for selecting genetically diverse genotypes despite their phenotypic similarity, and lines PF 9027, PF 950351, PF 030132, PF 979002, PF 040488 and IWT 04019 can be used as parental for future crosses, since they have genetic diversity and suitable agronomic traits.
MIPS 24 Micron Observations of the Hubble Deep Field South: Probing the IR-Radio Correlation of Galaxies at z > 1
M. T. Huynh,E. Gawiser,D. Marchesini,G. Brammer,L. Guaita
Physics , 2010, DOI: 10.1088/0004-637X/723/2/1110
Abstract: We present MIPS 24 micron observations of the Hubble Deep Field South taken with the Spitzer Space Telescope. The resulting image is 254 arcmin^2 in size and has a sensitivity ranging between ~12 to ~30 microJy rms, with a median sensitivity of ~20 microJy rms. A total of 495 sources have been cataloged with a signal-to-noise ratio greater than 5 sigma. The source catalog is presented as well as source counts which have been corrected for completeness and flux boosting. The IR sources are then combined with MUSYC optical/NIR and ATHDFS radio observations to obtain redshifts and radio flux densities of the sample. We use the IR/radio flux density ratio (q_24) to explore the IR-radio correlation for this IR sample and find q_24 = 0.71 +- 0.31 for sources detected in both IR and radio. The results are extended by stacking IR sources not detected in the radio observations and we derive an average q_24 for redshift bins between 0 < z < 2.5. We find the high redshift (z > 1) sources have an average q_{24} ratio which is better fit by local LIRG SEDs rather than local ULIRG SEDs, indicating that high redshift ULIRGs differ in their IR/radio properties. So ULIRGs at high redshift have SEDs different from those found locally. Infrared faint radio sources are examined, and while nine radio sources do not have a MIPS detection and are therefore radio-loud AGN, only one radio source has an extreme IRAC 3.6 micron to radio flux density ratio indicating it is a radio-loud AGN at z > 1.
Transloca??es cromoss?micas entre trigo e centeio: uma alternativa ao melhoramento
Casassola, Alice;Brammer, Sandra Patussi;
Ciência Rural , 2011, DOI: 10.1590/S0103-84782011005000106
Abstract: translocations are structural chromosomal rearrangements which involve segments with different length belonging to homologous or non homologous chromosomes. either natural or induced occurrence of translocations have been enabled an improvement in the plant breeding, when these translocated segments carry resistance genes to biotic and abiotic stress. rye is a grass largely used to transfer genes to wheat such as resistance genes to leaf rust, stem rust and genes that support the wheat yield, either in grain quantity or in quality. thus, the aim of this paper was to review the main translocations involving wheat and rye, which demonstrated, from the data analyzed, that translocations involving chromosomes 1 and 2 were more advantageous for grain yield in wheat and that the others were important, especially, in the transfer of resistance genes. therefore, this strategy has demonstrated effectiveness on search for new genes that favor the cultivation of wheat and its use has grown greatly in recent years.
Efeito do Soil-borne wheat mosaic virus sobre o metabolismo de cinco genótipos de trigo com diferentes níveis de resistência à doen?a
Souza, Rocheli de;Schons, Jurema;Brammer, Sandra P.;Prestes, Ariano M.;Scheeren, Pedro L.;Nicolini-Teixeira, Fernanda;Cecchetti, Dileta;Lanzarini, Ariane C.;
Fitopatologia Brasileira , 2005, DOI: 10.1590/S0100-41582005000400010
Abstract: the objective of this study was to verify the metabolic alterations induced by soil-borne wheat mosaic virus (sbwmv), one of the most economically harmful viruses infecting wheat (triticum aestivum) farming. the study analyzed the levels of soluble proteins and determined the activities of peroxidase and protease in four wheat cultivars (brs guabiju, br 23, brs 179, brs 194) and one line (pf 980524) with different levels of resistance to the virus. the data obtained were submitted to analysis of variance, and averages were compared by duncan's test at 5%. soluble protein levels were higher in plants without symptoms, while peroxidase and protease activities were higher in plants with mosaic symptoms than in assymptomatic plants. moreover, it appeared that genotypes with high susceptibility to sbwmv have high protease activity. these results could help in the design of future studies aimed at controlling the virus through inhibition of protease.
Chromosome characterization in Thinopyrum ponticum (Triticeae, Poaceae) using in situ hybridization with different DNA sequences
Brasileiro-Vidal, Ana Christina;Cuadrado, Angeles;Brammer, Sandra P.;Zanatta, Ana Christina A.;Prestes, Ariano M.;Moraes-Fernandes, Maria Irene B.;Guerra, Marcelo;
Genetics and Molecular Biology , 2003, DOI: 10.1590/S1415-47572003000400014
Abstract: thinopyrum ponticum (2n = 10x = 70, jjjjsjs) belongs to the triticeae tribe, and is currently used as a source of pathogen resistance genes in wheat breeding. in order to characterize its chromosomes, the number and position of 45s and 5s rdna sites, as well as the distribution of the repetitive dna sequences pas1 and psc119.2, were identified by fluorescent in situ hybridization. the number of nucleoli and nors was also recorded after silver nitrate staining. seventeen 45s and twenty 5s rdna sites were observed on the short arms of 17 chromosomes, the 45s rdna was always located terminally. on three other chromosomes, only the 5s rdna site was observed. silver staining revealed a high number of ag-nors (14 to 17) on metaphase chromosomes, whereas on interphase nuclei there was a large variation in number of nucleoli (one to 15), most of them (82.8%) ranging between four and nine. the pas1 probe hybridized to the terminal region of both arms of all 70 chromosomes. in addition, a disperse labeling was observed throughout the chromosomes, except in centromeric and most pericentromeric regions. when the psc119.2 sequence was used as a probe, terminal labeling was observed on the short arms of 17 chromosomes and on the long arms of five others. the relative position of 45s and 5s rdna sites, together with the hybridization pattern of pas1 and psc119.2 probes, should allow whole chromosomes or chromosome segments of th. ponticum to be identified in inbred lines of wheat x th. ponticum.
Frontier Fields : Combining HST, VLT and Spitzer data to explore the $z$$\sim$8 Universe behind the lensing cluster MACS0416$-$2403
N. Laporte,A. Streblyanska,S. Kim,R. Pelló,F. E. Bauer,D. Bina,G. Brammer,M. A. De Leo,L. Infante,I. Pérez-Fournon
Physics , 2014, DOI: 10.1051/0004-6361/201425040
Abstract: (Abridged) The HST Frontier Fields project started at the end of 2013 with the aim of providing extremely deep images of 6 massive galaxy clusters. One of the main goals of this program is to push several telescopes to their limits in order to provide the best current view of the earliest stages of the Universe. We present a detailed analysis of $z$$\sim$8 objects behind the HFFs lensing cluster, MACS0416-2403, combining 0.3-1.6 $\mu$m imaging from HST, ground-based $K_s$ imaging from VLT HAWK-I, and 3.6 $\mu$m and 4.5 $\mu$m Spitzer Space Telescope. We apply the classical Lyman Break technique, combining non-detection criteria and color-selection. In order to avoid contamination by mid-$z$ interlopers, we require a strong break between optical and near infrared data. The luminosity function at $z$$\sim$8 is computed using a MC method taking advantage of the SED-fitting results. A piece of cautionary information is gleaned from new deep optical photometry of a previously identified $z$$\sim$8 galaxy in this cluster, which is now firmly detected as a mid-$z$ interloper with a strong $\approx1.5$ mag Balmer break (between F606W and F125W). Using the SED of this interloper, we estimate the contamination rate of our MACS0416$-$2403 sample, as well as for previous samples in Abell 2744 based on HFF data. Our selection recovers 4 robust objects with m$_{F160W}$ ranging from 26.0 to 27.9 AB and located in modest amplification regions ($\mu<$2.4). Two of the objects display a secondary break between the IRAC 3.6 $\mu$m and 4.5 $\mu$m bands which could be associated to the Balmer break or emission lines at $z$$\sim$8. The candidates generally have star formation rates around $\sim$10 M$_{\odot}$/yr and sizes ranging from 0.2 to 0.5 kpc, in good agreement with previous observations and expectations for objects in the early Universe.
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