344 research outputs found

    Cytogenetical studies in five Atlantic Anguilliformes fishes

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    The order Anguilliformes comprises 15 families, 141 genera and 791 fish species. Eight families had at least one karyotyped species, with a prevalence of 2n = 38 chromosomes and high fundamental numbers (FN). The only exception to this pattern is the family Muraenidae, in which the eight species analyzed presented 2n = 42 chromosomes. Despite of the large number of Anguilliformes species, karyotypic reports are available for only a few representatives. In the present work, a species of Ophichthidae, Myrichthys ocellatus (2n = 38; 8m+14sm+10st+6a; FN = 70) and four species of Muraenidae, Enchelycore nigricans (2n = 42; 6m+8sm+12st+16a; FN = 68), Gymnothorax miliaris (2n = 42; 14m+18sm+10st; FN = 84), G. vicinus (2n = 42; 8m+6sm+28a; FN = 56) and Muraena pavonina (2n = 42; 6m+4sm+32a; FN = 52), collected along the Northeastern coast of Brazil and around the St Peter and St Paul Archipelago were analyzed. Typical large metacentric chromosomes were observed in all species. Conspicuous polymorphic heterochromatic regions were observed at the centromeres of most chromosomes and at single ribosomal sites. The data obtained for Ophichthidae corroborate the hypothesis of a karyotypic diversification mainly due to pericentric inversions and Robertsonian rearrangements, while the identification of constant chromosome numbers in Muraenidae (2n = 42) suggests a karyotype diversification through pericentric inversions and heterochromatin processes

    Organometallic indolo[3,2-c]quinolines versus indolo[3,2-d]benzazepines: synthesis, structural and spectroscopic characterization, and biological efficacy

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    The synthesis of ruthenium(II) and osmium(II) arene complexes with the closely related indolo[3,2-c]quinolines N-(11H-indolo[3,2-c]quinolin-6-yl)-ethane-1,2-diamine (L1) and Nâ€Č-(11H-indolo[3,2-c]quinolin-6-yl)-N,N-dimethylethane-1,2-diamine (L2) and indolo[3,2-d]benzazepines N-(7,12-dihydroindolo-[3,2-d][1]benzazepin-6-yl)-ethane-1,2-diamine (L3) and Nâ€Č-(7,12-dihydroindolo-[3,2-d][1]benzazepin-6-yl)-N,N-dimethylethane-1,2-diamine (L4) of the general formulas [(η6-p-cymene)MII(L1)Cl]Cl, where M is Ru (4) and Os (6), [(η6-p-cymene)MII(L2)Cl]Cl, where M is Ru (5) and Os (7), [(η6-p-cymene)MII(L3)Cl]Cl, where M is Ru (8) and Os (10), and [(η6-p-cymene)MII(L4)Cl]Cl, where M is Ru (9) and Os (11), is reported. The compounds have been comprehensively characterized by elemental analysis, electrospray ionization mass spectrometry, spectroscopy (IR, UV–vis, and NMR), and X-ray crystallography (L1·HCl, 4·H2O, 5, and 9·2.5H2O). Structure–activity relationships with regard to cytotoxicity and cell cycle effects in human cancer cells as well as cyclin-dependent kinase (cdk) inhibition and DNA intercalation in cell-free settings have been established. The metal-free indolo[3,2-c]quinolines inhibit cancer cell growth in vitro, with IC50 values in the high nanomolar range, whereas those of the related indolo[3,2-d]benzazepines are in the low micromolar range. In cell-free experiments, these classes of compounds inhibit the activity of cdk2/cyclin E, but the much higher cytotoxicity and stronger cell cycle effects of indoloquinolines L1 and 7 are not paralleled by a substantially higher kinase inhibition compared with indolobenzazepines L4 and 11, arguing for additional targets and molecular effects, such as intercalation into DNA

    Risk factors for pre-term birth in Iraq: a case-control study

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    BACKGROUND: Preterm birth (PTB)is a major clinical problem associated with perinatal mortality and morbidity. The aim of the present study is to identify risk factors associated with PTB in Mosul, Iraq. METHODS: A case-control study was conducted in Mosul, Iraq, from 1(st )September, 2003 to 28(th )February, 2004. RESULTS: A total of 200 cases of PTB and 200 controls of full-term births were screened and enrolled in the study. Forward logistic regression analysis was used in the analysis. Several significant risk associations between PTB and the following risk factors were identified: poor diet (OR = 4.33), heavy manual work (OR = 1.70), caring for domestic animals (OR = 5.06), urinary tract infection (OR = 2.85), anxiety (OR = 2.16), cervical incompetence (OR = 4.74), multiple pregnancies (OR = 7.51), direct trauma to abdomen (OR = 3.76) and abortion (OR = 6.36). CONCLUSION: The main determinants of PTB in Iraq were low socio-economic status and factors associated with it, such as heavy manual work and caring for domestic animals, in addition to urinary tract infections and poor obstetric history

    Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

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    The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≄20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≀pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≀{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration

    Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal
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