2,598 research outputs found
Cultivation of algae in photobioreator and obtention of biodiesel
In this work we described the cultivation of Chlorella vulgaris in a photobioreactor to algal biomass production. The dried biomass was used as feedstock for biodiesel production, it presented 26% lipids and via sonocatalysis stage of the methodology resulted in 60% of fatty acid methyl esters (FAME). The FAME content was confirmed by Gas Chromatography (GC).CNPqFAPERGSCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES
Transcriptome profiling of rabbit parthenogenetic blastocysts developed under in vivo conditions
Parthenogenetic embryos are one attractive alternative as a source of embryonic stem cells, although many aspects related to the biology of parthenogenetic embryos and parthenogenetically derived cell lines still need to be elucidated. The present work was conducted to investigate the gene expression profile of rabbit parthenote embryos cultured under in vivo conditions using microarray analysis. Transcriptomic profiles indicate 2541 differentially expressed genes between parthenotes and normal in vivo fertilised blastocysts, of which 76 genes were upregulated and 16 genes downregulated in in vivo cultured parthenote blastocyst, using 3 fold-changes as a cut-off. While differentially upregulated expressed genes are related to transport and protein metabolic process, downregulated expressed genes are related to DNA and RNA binding. Using microarray data, 6 imprinted genes were identified as conserved among rabbits, humans and mice: GRB10, ATP10A, ZNF215, NDN, IMPACT and SFMBT2. We also found that 26 putative genes have at least one member of that gene family imprinted in other species. These data strengthen the view that a large fraction of genes is differentially expressed between parthenogenetic and normal embryos cultured under the same conditions and offer a new approach to the identification of imprinted genes in rabbit. Š 2012 Naturil-Alfonso et al.This work was supported by Generalitat Valenciana research programme (Prometeo 2009/125). Carmen Naturil was supported by Generalitat Valenciana research programme (Prometeo 2009/125). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Naturil Alfonso, C.; Saenz De Juano Ribes, MDLD.; Peùaranda, D.; Vicente Antón, JS.; Marco JimÊnez, F. (2012). Transcriptome profiling of rabbit parthenogenetic blastocysts developed under in vivo conditions. PLoS ONE. 7(12):1-11. https://doi.org/10.1371/journal.pone.0051271S111712Harness, J. V., Turovets, N. A., Seiler, M. J., Nistor, G., Altun, G., Agapova, L. S., ⌠Keirstead, H. S. (2011). Equivalence of Conventionally-Derived and Parthenote-Derived Human Embryonic Stem Cells. PLoS ONE, 6(1), e14499. doi:10.1371/journal.pone.0014499Lu, Z., Zhu, W., Yu, Y., Jin, D., Guan, Y., Yao, R., ⌠Zhou, Q. (2010). Derivation and long-term culture of human parthenogenetic embryonic stem cells using human foreskin feeders. Journal of Assisted Reproduction and Genetics, 27(6), 285-291. doi:10.1007/s10815-010-9408-5Koh, C. J., Delo, D. M., Lee, J. W., Siddiqui, M. M., Lanza, R. P., Soker, S., ⌠Atala, A. (2009). Parthenogenesis-derived multipotent stem cells adapted for tissue engineering applications. Methods, 47(2), 90-97. doi:10.1016/j.ymeth.2008.08.002Vrana, K. E., Hipp, J. D., Goss, A. M., McCool, B. A., Riddle, D. R., Walker, S. J., ⌠Cibelli, J. B. (2003). Nonhuman primate parthenogenetic stem cells. Proceedings of the National Academy of Sciences, 100(Supplement 1), 11911-11916. doi:10.1073/pnas.2034195100Chen, Z., Liu, Z., Huang, J., Amano, T., Li, C., Cao, S., ⌠Liu, L. (2009). Birth of Parthenote Mice Directly from Parthenogenetic Embryonic Stem Cells. Stem Cells, 27(9), 2136-2145. doi:10.1002/stem.158Sritanaudomchai, H., Ma, H., Clepper, L., Gokhale, S., Bogan, R., Hennebold, J., ⌠Mitalipov, S. (2010). Discovery of a novel imprinted gene by transcriptional analysis of parthenogenetic embryonic stem cells. Human Reproduction, 25(8), 1927-1941. doi:10.1093/humrep/deq144Fang, Z. F., Gai, H., Huang, Y. Z., Li, S. G., Chen, X. J., Shi, J. J., ⌠Sheng, H. Z. (2006). Rabbit embryonic stem cell lines derived from fertilized, parthenogenetic or somatic cell nuclear transfer embryos. Experimental Cell Research, 312(18), 3669-3682. doi:10.1016/j.yexcr.2006.08.013Wang, S., Tang, X., Niu, Y., Chen, H., Li, B., Li, T., ⌠Ji, W. (2007). Generation and Characterization of Rabbit Embryonic Stem Cells. Stem Cells, 25(2), 481-489. doi:10.1634/stemcells.2006-0226Piedrahita, J. A., Anderson, G. B., & BonDurant, R. H. (1990). On the isolation of embryonic stem cells: Comparative behavior of murine, porcine and ovine embryos. Theriogenology, 34(5), 879-901. doi:10.1016/0093-691x(90)90559-cNaturil-Alfonso, C., Saenz-de-Juano, M. D., Peùaranda, D. S., Vicente, J. S., & Marco-JimÊnez, F. (2011). Parthenogenic blastocysts cultured under in vivo conditions exhibit proliferation and differentiation expression genes similar to those of normal embryos. Animal Reproduction Science, 127(3-4), 222-228. doi:10.1016/j.anireprosci.2011.08.005Besenfelder, U., Strouhal, C., & Brem, G. (1998). A Method for Endoscopic Embryo Collection and Transfer in the Rabbit. Journal of Veterinary Medicine Series A, 45(1-10), 577-579. doi:10.1111/j.1439-0442.1998.tb00861.xMehaisen, G. M. K., Viudes-de-Castro, M. P., Vicente, J. S., & Lavara, R. (2006). In vitro and in vivo viability of vitrified and non-vitrified embryos derived from eCG and FSH treatment in rabbit does. Theriogenology, 65(7), 1279-1291. doi:10.1016/j.theriogenology.2005.08.007Bilodeau-Goeseels, S., & Schultz, G. A. (1997). Changes in Ribosomal Ribonucleic Acid Content Within in Vitro-produced Bovine Embryos1. Biology of Reproduction, 56(5), 1323-1329. doi:10.1095/biolreprod56.5.1323Conesa, A., Gotz, S., Garcia-Gomez, J. M., Terol, J., Talon, M., & Robles, M. (2005). Blast2GO: a universal tool for annotation, visualization and analysis in functional genomics research. Bioinformatics, 21(18), 3674-3676. doi:10.1093/bioinformatics/bti610Edgar, R. (2002). Gene Expression Omnibus: NCBI gene expression and hybridization array data repository. Nucleic Acids Research, 30(1), 207-210. doi:10.1093/nar/30.1.207Weltzien, F.-A., Pasqualini, C., Vernier, P., & Dufour, S. (2005). A quantitative real-time RT-PCR assay for European eel tyrosine hydroxylase. General and Comparative Endocrinology, 142(1-2), 134-142. doi:10.1016/j.ygcen.2004.12.019Llobat, L., Marco-JimÊnez, F., Peùaranda, D., Saenz-de-Juano, M., & Vicente, J. (2011). Effect of Embryonic Genotype on Reference Gene Selection for RT-qPCR Normalization. Reproduction in Domestic Animals, 47(4), 629-634. doi:10.1111/j.1439-0531.2011.01934.xLiu, N., Enkemann, S. A., Liang, P., Hersmus, R., Zanazzi, C., Huang, J., ⌠Liu, L. (2010). Genome-wide Gene Expression Profiling Reveals Aberrant MAPK and Wnt Signaling Pathways Associated with Early Parthenogenesis. Journal of Molecular Cell Biology, 2(6), 333-344. doi:10.1093/jmcb/mjq029Abdoon, A. S., Ghanem, N., Kandil, O. M., Gad, A., Schellander, K., & Tesfaye, D. (2012). cDNA microarray analysis of gene expression in parthenotes and in vitro produced buffalo embryos. Theriogenology, 77(6), 1240-1251. doi:10.1016/j.theriogenology.2011.11.004Labrecque, R., & Sirard, M.-A. (2011). Gene expression analysis of bovine blastocysts produced by parthenogenic activation or fertilisation. Reproduction, Fertility and Development, 23(4), 591. doi:10.1071/rd10243Rizos, D., Clemente, M., Bermejo-Alvarez, P., de La Fuente, J., Lonergan, P., & GutiÊrrez-Adån, A. (2008). Consequences ofIn VitroCulture Conditions on Embryo Development and Quality. Reproduction in Domestic Animals, 43, 44-50. doi:10.1111/j.1439-0531.2008.01230.xLonergan, P., Rizos, D., Kanka, J., Nemcova, L., Mbaye, A., Kingston, M., ⌠Boland, M. (2003). Temporal sensitivity of bovine embryos to culture environment after fertilization and the implications for blastocyst quality. Reproduction, 337-346. doi:10.1530/rep.0.1260337Memili, E., & First, N. L. (2000). Zygotic and embryonic gene expression in cow: a review of timing and mechanisms of early gene expression as compared with other species. Zygote, 8(1), 87-96. doi:10.1017/s0967199400000861Latham, K. E. (2001). Embryonic genome activation. Frontiers in Bioscience, 6(3), d748-759. doi:10.2741/a639Niemann, H., & Wrenzycki, C. (2000). Alterations of expression of developmentally important genes in preimplantation bovine embryos by in vitro culture conditions: Implications for subsequent development. Theriogenology, 53(1), 21-34. doi:10.1016/s0093-691x(99)00237-xCorcoran, D., Fair, T., Park, S., Rizos, D., Patel, O. V., Smith, G. W., ⌠Lonergan, P. (2006). Suppressed expression of genes involved in transcription and translation in in vitro compared with in vivo cultured bovine embryos. Reproduction, 131(4), 651-660. doi:10.1530/rep.1.01015Morison, I. M., Ramsay, J. P., & Spencer, H. G. (2005). A census of mammalian imprinting. Trends in Genetics, 21(8), 457-465. doi:10.1016/j.tig.2005.06.008Bischoff, S. R., Tsai, S., Hardison, N., Motsinger-Reif, A. A., Freking, B. A., Nonneman, D., ⌠Piedrahita, J. A. (2009). Characterization of Conserved and Nonconserved Imprinted Genes in Swine1. Biology of Reproduction, 81(5), 906-920. doi:10.1095/biolreprod.109.078139Cruz-Correa, M., Zhao, R., Oveido, M., Bernabe, R. D., Lacourt, M., Cardona, A., ⌠Giardiello, F. M. (2009). Temporal stability and age-related prevalence of loss of imprinting of the insulin-like growth factor-2 gene. Epigenetics, 4(2), 114-118. doi:10.4161/epi.4.2.7954Park, C.-H., Uh, K.-J., Mulligan, B. P., Jeung, E.-B., Hyun, S.-H., Shin, T., ⌠Lee, C.-K. (2011). Analysis of Imprinted Gene Expression in Normal Fertilized and Uniparental Preimplantation Porcine Embryos. PLoS ONE, 6(7), e22216. doi:10.1371/journal.pone.0022216Thurston, A., Taylor, J., Gardner, J., Sinclair, K. D., & Young, L. E. (2007). Monoallelic expression of nine imprinted genes in the sheep embryo occurs after the blastocyst stage. Reproduction, 135(1), 29-40. doi:10.1530/rep-07-0211Li, Y., & Sasaki, H. (2011). Genomic imprinting in mammals: its life cycle, molecular mechanisms and reprogramming. Cell Research, 21(3), 466-473. doi:10.1038/cr.2011.15Mamo, S., Gal, A., Polgar, Z., & Dinnyes, A. (2008). Expression profiles of the pluripotency marker gene POU5F1 and validation of reference genes in rabbit oocytes and preimplantation stage embryos. BMC Molecular Biology, 9(1), 67. doi:10.1186/1471-2199-9-67Navarrete Santos, A., Tonack, S., Kirstein, M., Pantaleon, M., Kaye, P., & Fischer, B. (2004). Insulin acts via mitogen-activated protein kinase phosphorylation in rabbit blastocysts. Reproduction, 128(5), 517-526. doi:10.1530/rep.1.0020
The Polarised Valence Quark Distribution from semi-inclusive DIS
The semi-inclusive difference asymmetry A^{h^{+}-h^{-}} for hadrons of
opposite charge has been measured by the COMPASS experiment at CERN. The data
were collected in the years 2002-2004 using a 160 GeV polarised muon beam
scattered off a large polarised ^6LiD target and cover the range 0.006 < x <
0.7 and 1 < Q^2 < 100 (GeV/c)^2. In leading order QCD (LO) the asymmetry
A_d^{h^{+}-h^{-}} measures the valence quark polarisation and provides an
evaluation of the first moment of Delta u_v + Delta d_v which is found to be
equal to 0.40 +- 0.07 (stat.) +- 0.05 (syst.) over the measured range of x at
Q^2 = 10 (GeV/c)^2. When combined with the first moment of g_1^d previously
measured on the same data, this result favours a non-symmetric polarisation of
light quarks Delta u-bar = - Delta d-bar at a confidence level of two standard
deviations, in contrast to the often assumed symmetric scenario Delta u-bar =
Delta d-bar = Delta s-bar = Delta s.Comment: 7 pages, 3 figures, COMPASS, revised: details added, author list
update
Charge separation relative to the reaction plane in Pb-Pb collisions at TeV
Measurements of charge dependent azimuthal correlations with the ALICE
detector at the LHC are reported for Pb-Pb collisions at TeV. Two- and three-particle charge-dependent azimuthal correlations in
the pseudo-rapidity range are presented as a function of the
collision centrality, particle separation in pseudo-rapidity, and transverse
momentum. A clear signal compatible with a charge-dependent separation relative
to the reaction plane is observed, which shows little or no collision energy
dependence when compared to measurements at RHIC energies. This provides a new
insight for understanding the nature of the charge dependent azimuthal
correlations observed at RHIC and LHC energies.Comment: 12 pages, 3 captioned figures, authors from page 2 to 6, published
version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/286
A note on comonotonicity and positivity of the control components of decoupled quadratic FBSDE
In this small note we are concerned with the solution of Forward-Backward
Stochastic Differential Equations (FBSDE) with drivers that grow quadratically
in the control component (quadratic growth FBSDE or qgFBSDE). The main theorem
is a comparison result that allows comparing componentwise the signs of the
control processes of two different qgFBSDE. As a byproduct one obtains
conditions that allow establishing the positivity of the control process.Comment: accepted for publicatio
Multiplicity dependence of jet-like two-particle correlations in p-Pb collisions at = 5.02 TeV
Two-particle angular correlations between unidentified charged trigger and
associated particles are measured by the ALICE detector in p-Pb collisions at a
nucleon-nucleon centre-of-mass energy of 5.02 TeV. The transverse-momentum
range 0.7 5.0 GeV/ is examined,
to include correlations induced by jets originating from low
momen\-tum-transfer scatterings (minijets). The correlations expressed as
associated yield per trigger particle are obtained in the pseudorapidity range
. The near-side long-range pseudorapidity correlations observed in
high-multiplicity p-Pb collisions are subtracted from both near-side
short-range and away-side correlations in order to remove the non-jet-like
components. The yields in the jet-like peaks are found to be invariant with
event multiplicity with the exception of events with low multiplicity. This
invariance is consistent with the particles being produced via the incoherent
fragmentation of multiple parton--parton scatterings, while the yield related
to the previously observed ridge structures is not jet-related. The number of
uncorrelated sources of particle production is found to increase linearly with
multiplicity, suggesting no saturation of the number of multi-parton
interactions even in the highest multiplicity p-Pb collisions. Further, the
number scales in the intermediate multiplicity region with the number of binary
nucleon-nucleon collisions estimated with a Glauber Monte-Carlo simulation.Comment: 23 pages, 6 captioned figures, 1 table, authors from page 17,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/161
Multi-particle azimuthal correlations in p-Pb and Pb-Pb collisions at the CERN Large Hadron Collider
Measurements of multi-particle azimuthal correlations (cumulants) for charged
particles in p-Pb and Pb-Pb collisions are presented. They help address the
question of whether there is evidence for global, flow-like, azimuthal
correlations in the p-Pb system. Comparisons are made to measurements from the
larger Pb-Pb system, where such evidence is established. In particular, the
second harmonic two-particle cumulants are found to decrease with multiplicity,
characteristic of a dominance of few-particle correlations in p-Pb collisions.
However, when a gap is placed to suppress such correlations,
the two-particle cumulants begin to rise at high-multiplicity, indicating the
presence of global azimuthal correlations. The Pb-Pb values are higher than the
p-Pb values at similar multiplicities. In both systems, the second harmonic
four-particle cumulants exhibit a transition from positive to negative values
when the multiplicity increases. The negative values allow for a measurement of
to be made, which is found to be higher in Pb-Pb collisions at
similar multiplicities. The second harmonic six-particle cumulants are also
found to be higher in Pb-Pb collisions. In Pb-Pb collisions, we generally find
which is indicative of a Bessel-Gaussian
function for the distribution. For very high-multiplicity Pb-Pb
collisions, we observe that the four- and six-particle cumulants become
consistent with 0. Finally, third harmonic two-particle cumulants in p-Pb and
Pb-Pb are measured. These are found to be similar for overlapping
multiplicities, when a gap is placed.Comment: 25 pages, 11 captioned figures, 3 tables, authors from page 20,
published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/87
Transverse sphericity of primary charged particles in minimum bias proton-proton collisions at , 2.76 and 7 TeV
Measurements of the sphericity of primary charged particles in minimum bias
proton--proton collisions at , 2.76 and 7 TeV with the ALICE
detector at the LHC are presented. The observable is linearized to be collinear
safe and is measured in the plane perpendicular to the beam direction using
primary charged tracks with GeV/c in . The
mean sphericity as a function of the charged particle multiplicity at
mid-rapidity () is reported for events with different
scales ("soft" and "hard") defined by the transverse momentum of the leading
particle. In addition, the mean charged particle transverse momentum versus
multiplicity is presented for the different event classes, and the sphericity
distributions in bins of multiplicity are presented. The data are compared with
calculations of standard Monte Carlo event generators. The transverse
sphericity is found to grow with multiplicity at all collision energies, with a
steeper rise at low , whereas the event generators show the
opposite tendency. The combined study of the sphericity and the mean with multiplicity indicates that most of the tested event generators
produce events with higher multiplicity by generating more back-to-back jets
resulting in decreased sphericity (and isotropy). The PYTHIA6 generator with
tune PERUGIA-2011 exhibits a noticeable improvement in describing the data,
compared to the other tested generators.Comment: 21 pages, 9 captioned figures, 3 tables, authors from page 16,
published version, figures from
http://aliceinfo.cern.ch/ArtSubmission/node/308
Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV
A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay
channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7
TeV is presented. The data were collected at the LHC, with the CMS detector,
and correspond to an integrated luminosity of 4.6 inverse femtobarns. No
significant excess is observed above the background expectation, and upper
limits are set on the Higgs boson production cross section. The presence of the
standard model Higgs boson with a mass in the 270-440 GeV range is excluded at
95% confidence level.Comment: Submitted to JHE
Conserved molecular interactions in centriole-to-centrosome conversion.
Centrioles are required to assemble centrosomes for cell division and cilia for motility and signalling. New centrioles assemble perpendicularly to pre-existing ones in G1-S and elongate throughout S and G2. Fully elongated daughter centrioles are converted into centrosomes during mitosis to be able to duplicate and organize pericentriolar material in the next cell cycle. Here we show that centriole-to-centrosome conversion requires sequential loading of Cep135, Ana1 (Cep295) and Asterless (Cep152) onto daughter centrioles during mitotic progression in both Drosophila melanogaster and human. This generates a molecular network spanning from the inner- to outermost parts of the centriole. Ana1 forms a molecular strut within the network, and its essential role can be substituted by an engineered fragment providing an alternative linkage between Asterless and Cep135. This conserved architectural framework is essential for loading Asterless or Cep152, the partner of the master regulator of centriole duplication, Plk4. Our study thus uncovers the molecular basis for centriole-to-centrosome conversion that renders daughter centrioles competent for motherhood.J.F., Z.L., S.S. and N.S.D. are supported from Programme Grant to D.M.G. from Cancer Research UK. H.R. is supported from MRC Programme Grant to D.M.G. J.F. thank the British Academy and the Royal Society for Newton International Fellowship and Z.L. thanks the Federation of European Biochemical Societies for the Long-Term postdoctoral Fellowship. The authors thank Nicola Lawrence and Alex Sossick for assistance with 3D-SIM.This is the author accepted manuscript. The final version is available from NPG via http://dx.doi.org/10.1038/ncb327
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