400 research outputs found

    Geochemical Sources and Availability of Amidophosphates on the Early Earth

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    Phosphorylation of (pre)biotically relevant molecules in aqueous medium has recently been demonstrated using water-soluble diamidophosphate (DAP). Questions arise relating to the prebiotic availability of DAP and other amidophosphosphorus species on the early earth. Herein, we demonstrate that DAP and other amino-derivatives of phosphates/phosphite are generated when Fe3P (proxy for mineral schreibersite), condensed phosphates, and reduced oxidation state phosphorus compounds, which could have been available on early earth, are exposed to aqueous ammonia solutions. DAP is shown to remain in aqueous solution under conditions where phosphate is precipitated out by divalent metals. These results show that nitrogenated analogues of phosphate and reduced phosphite species can be produced and remain in solution, overcoming the thermodynamic barrier for phosphorylation in water, increasing the possibility that abiotic phosphorylation reactions occurred in aqueous environments on early earth

    Extra-uterine (abdominal) full term foetus in a 15-day pregnant rabbit

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    [EN] Background: While ectopic pregnancies account for 1-2% of all pregnancies, abdominal pregnancy is extremely rare, accounting for approximately 1% of ectopic pregnancies. Extrauterine abdominal pregnancy is defined as the implantation and development of an embryo in the peritoneal cavity. The present report is the first of an incidental case of abdominal pregnancy within four full-term foetus simultaneously with 2 weeks of physiological gestation in a healthy doe rabbit. Case presentation: The doe was born on November 3, 2014 and the first partum took place on May 18, 2015. The doe had previously delivered and weaned an average of 12.0 +/- 1.41 live kits at birth (no stillbirths were recorded) during 5 consecutive pregnancies. The last mating was on December 18, 2015 and the detection of pregnancy failure post breeding (by abdominal palpation) on December 31, 2015. Then, the doe was artificially inseminated on January 27, 2016, diagnosed pregnant on February 11, 2016 and subsequently euthanized to recover the foetus. A ventral midline incision revealed a reproductive tract with 12 implantation sites with 15 days old foetus and 4 term foetus in abdominal cavity. There were two foetus floating on either side of the abdominal cavity and two suspended near the greater curvature of the stomach. They were attached to internal organs by means of one or 2 thread-like blood vessels that linked them to the abdominal surfaces. Conclusions: In our opinion a systematic monitoring of rabbit breeding should be included to fully understand and enhance current knowledge of this phenomenon of abdominal pregnancy.This work was supported by Spanish Research Project AGL2014-53405-C2-1-P (Interministerial Commission on Science and Technology).Marco-JimĂ©nez, F.; Garcia-Dominguez, X.; Valdes-HernĂĄndez, J.; Vicente AntĂłn, JS. (2017). Extra-uterine (abdominal) full term foetus in a 15-day pregnant rabbit. BMC Veterinary Research. 13:1-4. https://doi.org/10.1186/s12917-017-1229-7S1413Petracci M, Bianchi M, Cavani C. Development of rabbit meat products fortified with n-3 polyunsaturated fatty acids. Nutrients. 2009;1:111–8.FAOSTAT (Food and Agriculture Organization of the United Nations, authors). Available online: http://faostat.fao.org/site/569/DesktopDefault.aspx?PageID=569#ancor . Accessed Sept 2012.Segura Gil P, Peris Palau B, MartĂ­nez MartĂ­nez J, Ortega Porcel J, Corpa Arenas JM. Abdominal pregnancies in farm rabbits. Theriogenology. 2004;62:642–51.Rosell JM, de la Fuente LF. Culling and mortality in breeding rabbits. Prev Vet Med. 2009;88:120–7.Tena-Betancourt E, Tena-Betancourt CA, ZĂșniga-Muñoz AM, HernĂĄndez-GodĂ­nez B, Ibåñez-Contreras A, Graullera-Rivera V. Multiple extrauterine pregnancy with early and near full-term mummified foetuses in a New Zealand white rabbit (Oryctolagus Cuniculus). J Am Assoc Lab Anim Sci. 2014;53:204–7.SĂĄnchez JP, Theilgaard P, MĂ­nguez C, Baselga M. Constitution and evaluation of a long-lived productive rabbit line. J Anim Sci. 2008;86:515–25.Savietto D, Friggens NC, Pascual JJ. Reproductive robustness differs between generalist and specialist maternal rabbit lines: the role of acquisition and allocation of resources. Genet Sel Evol. 2015;47:2.Viudes-de-Castro MP, Vicente JS. Effect of sperm count on the fertility and prolificity rates of meat rabbits. Anim Reprod Sci. 1997;46:313–9.Marco-JimĂ©nez F, Garcia-Dominguez X, Jimenez-Trigos E, Vera-Donoso CD, Vicente JS. Vitrification of kidney precursors as a new source for organ transplantation. Cryobiology. 2015;70:278–82.Garcia-Dominguez X, Vera-Donoso CD, Jimenez-Trigos E, Vicente JS, Marco-Jimenez. First steps towards organ banks: vitrification of renal primordial. Cryo Letters. 2016;37:47–52.Arvidsson A. Extra-uterine pregnancy in a rabbit. Vet Rec. 1998;142:176.GliĆĄić A, Radunović N, Atanacković J. Methotrexate and fallopian tubes in ectopic pregnancy. Acta veterinaria. 2006;56:375–82.Nwobodo EI. Abdominal pregnancy. A case report. Ann Afr Med. 2004;3:195–6.Nassali MN, Benti TM, Bandani-Ntsabele M, Musinguzi E. A case report of an asymptomatic late term abdominal pregnancy with a live birth at 41 weeks of gestation. BMC Res Notes. 2016;9:31.Baffoe P, Fofie C, Gandau BN. Term abdominal pregnancy with healthy new-born: a case report. Ghana Med J. 2011;45:81–3.Eleje GU, Adewae O, Osuagwu IK, Obianika CE. Post-date extra-uterine abdominal pregnancy in a rhesus negative Nullipara with successful outcome: a case report. J Women's Health. 2013;6:2.Hong CC, Armstrong ML. Ectopic pregnancy in 2 guinea-pigs. Lab Anim. 1978;12:243–4.Peters LJ. Abdominal pregnancy in a golden hamster (Mesocricetus Auratus). Lab Anim Sci. 1982;32:392–3.Xiccato G, Trocino A, Boiti C, Brecchia G. Reproductive rhythm and litter weaning age as they affect rabbit doe performance and body energy balance. Anim Sci. 2005;81:289–96.Fortun-Lamothe L, De Rochambeau H, Lebas F, Tudela F. Influence of the number of suckling young on reproductive performance in intensively reared rabbits does. In: Blasco A, editor. Proceedings of the 7th world rabbit congress; 2002. p. 125–32

    NAD-Independent L-Lactate Dehydrogenase Is Required for L-Lactate Utilization in Pseudomonas stutzeri SDM

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    BACKGROUND: Various Pseudomonas strains can use L-lactate as their sole carbon source for growth. However, the L-lactate-utilizing enzymes in Pseudomonas have never been identified and further studied. METHODOLOGY/PRINCIPAL FINDINGS: An NAD-independent L-lactate dehydrogenase (L-iLDH) was purified from the membrane fraction of Pseudomonas stutzeri SDM. The enzyme catalyzes the oxidation of L-lactate to pyruvate by using FMN as cofactor. After cloning its encoding gene (lldD), L-iLDH was successfully expressed, purified from a recombinant Escherichia coli strain, and characterized. An lldD mutant of P. stutzeri SDM was constructed by gene knockout technology. This mutant was unable to grow on L-lactate, but retained the ability to grow on pyruvate. CONCLUSIONS/SIGNIFICANCE: It is proposed that L-iLDH plays an indispensable function in Pseudomonas L-lactate utilization by catalyzing the conversion of L-lactate into pyruvate

    Measurement of the tt¯tt¯ production cross section in pp collisions at √s=13 TeV with the ATLAS detector

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    A measurement of four-top-quark production using proton-proton collision data at a centre-of-mass energy of 13 TeV collected by the ATLAS detector at the Large Hadron Collider corresponding to an integrated luminosity of 139 fb−1 is presented. Events are selected if they contain a single lepton (electron or muon) or an opposite-sign lepton pair, in association with multiple jets. The events are categorised according to the number of jets and how likely these are to contain b-hadrons. A multivariate technique is then used to discriminate between signal and background events. The measured four-top-quark production cross section is found to be 26+17−15 fb, with a corresponding observed (expected) significance of 1.9 (1.0) standard deviations over the background-only hypothesis. The result is combined with the previous measurement performed by the ATLAS Collaboration in the multilepton final state. The combined four-top-quark production cross section is measured to be 24+7−6 fb, with a corresponding observed (expected) signal significance of 4.7 (2.6) standard deviations over the background-only predictions. It is consistent within 2.0 standard deviations with the Standard Model expectation of 12.0 ± 2.4 fb

    Measurement and interpretation of same-sign W boson pair production in association with two jets in pp collisions at s = 13 TeV with the ATLAS detector

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    This paper presents the measurement of fducial and diferential cross sections for both the inclusive and electroweak production of a same-sign W-boson pair in association with two jets (W±W±jj) using 139 fb−1 of proton-proton collision data recorded at a centre-of-mass energy of √s = 13 TeV by the ATLAS detector at the Large Hadron Collider. The analysis is performed by selecting two same-charge leptons, electron or muon, and at least two jets with large invariant mass and a large rapidity diference. The measured fducial cross sections for electroweak and inclusive W±W±jj production are 2.92 ± 0.22 (stat.) ± 0.19 (syst.)fb and 3.38±0.22 (stat.)±0.19 (syst.)fb, respectively, in agreement with Standard Model predictions. The measurements are used to constrain anomalous quartic gauge couplings by extracting 95% confdence level intervals on dimension-8 operators. A search for doubly charged Higgs bosons H±± that are produced in vector-boson fusion processes and decay into a same-sign W boson pair is performed. The largest deviation from the Standard Model occurs for an H±± mass near 450 GeV, with a global signifcance of 2.5 standard deviations

    Measurements of W+W−+ ≄ 1 jet production cross-sections in pp collisions at s \sqrt{s} = 13 TeV with the ATLAS detector

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    Fiducial and differential cross-section measurements of W+W− production in association with at least one hadronic jet are presented. These measurements are sensitive to the properties of electroweak-boson self-interactions and provide a test of perturbative quantum chromodynamics and the electroweak theory. The analysis is performed using proton-proton collision data collected at p s = 13TeV with the ATLAS experiment, corresponding to an integrated luminosity of 139 fb−1. Events are selected with exactly one oppositely charged electron-muon pair and at least one hadronic jet with a transverse momentum of pT > 30 GeV and a pseudorapidity of |ïżœ| < 4.5. After subtracting the background contributions and correcting for detector effects, the jet-inclusive W+W−+ ïżœ 1 jet fiducial cross-section and W+W−+ jets differential cross-sections with respect to several kinematic variables are measured. These measurements include leptonic quantities, such as the lepton transverse momenta and the transverse mass of the W+W− system, as well as jet-related observables such as the leading jet transverse momentum and the jet multiplicity. Limits on anomalous triple-gauge-boson couplings are obtained in a phase space where interference between the Standard Model amplitude and the anomalous amplitude is enhanced

    Combination of searches for heavy spin-1 resonances using 139 fb−1 of proton-proton collision data at s = 13 TeV with the ATLAS detector

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    A combination of searches for new heavy spin-1 resonances decaying into different pairings of W, Z, or Higgs bosons, as well as directly into leptons or quarks, is presented. The data sample used corresponds to 139 fb−1 of proton-proton collisions at = 13 TeV collected during 2015–2018 with the ATLAS detector at the CERN Large Hadron Collider. Analyses selecting quark pairs (qq, bb, , and tb) or third-generation leptons (Ï„Îœ and ττ) are included in this kind of combination for the first time. A simplified model predicting a spin-1 heavy vector-boson triplet is used. Cross-section limits are set at the 95% confidence level and are compared with predictions for the benchmark model. These limits are also expressed in terms of constraints on couplings of the heavy vector-boson triplet to quarks, leptons, and the Higgs boson. The complementarity of the various analyses increases the sensitivity to new physics, and the resulting constraints are stronger than those from any individual analysis considered. The data exclude a heavy vector-boson triplet with mass below 5.8 TeV in a weakly coupled scenario, below 4.4 TeV in a strongly coupled scenario, and up to 1.5 TeV in the case of production via vector-boson fusion

    Determination of the parton distribution functions of the proton using diverse ATLAS data from pp collisions at √s = 7, 8 and 13 TeV

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    This paper presents an analysis at next-to-next-to-leading order in the theory of quantum chromodynamics for the determination of a new set of proton parton distribution functions using diverse measurements in pp collisions at \sqrt{s} = 7, 8 and 13 TeV, performed by the ATLAS experiment at the Large Hadron Collider, together with deep inelastic scattering data from ep collisions at the HERA collider. The ATLAS data sets considered are differential cross-section measurements of inclusive W^{±} and Z/gamma^{*} boson production, W^{±} and Z boson production in association with jets, t\bar{t} production, inclusive jet production and direct photon production. In the analysis, particular attention is paid to the correlation of systematic uncertainties within and between the various ATLAS data sets and to the impact of model, theoretical and parameterisation uncertainties. The resulting set of parton distribution functions is called ATLASpdf21
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