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Institution

Sofia University

EducationSofia, Bulgaria
About: Sofia University is a education organization based out in Sofia, Bulgaria. It is known for research contribution in the topics: Large Hadron Collider & Standard Model. The organization has 8533 authors who have published 15730 publications receiving 306320 citations. The organization is also known as: University of Sofia & BFUS.


Papers
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Journal ArticleDOI
TL;DR: A clear effect of fumigation depth on the survival of the invading strain T was noted, as a progressive increase of depth coincided with a progressively enhanced inoculant survival rate, consistent with the hypothesis that soil systems with reduced biological complexity offer enhanced opportunities for invading microbial species to establish and persist.
Abstract: A loamy sand soil sampled from a species-rich permanent grassland at a long-term experimental site (Wildekamp, Bennekom, The Netherlands) was used to construct soil microcosms in which the microbial community compositions had been modified by fumigation at different intensities (depths) As expected, increasing depth of fumigation was shown to result in progressively increasing effects on the microbiological soil parameters, as determined by cultivation-based as well as cultivation-independent (PCR-DGGE, PLFA) methods Both at 7 and at 60 days after fumigation, shifts in the bacterial, fungal and protozoan communities were noted, indicating that altered community compositions had emerged following a transition phase At the level of bacteria culturable on plates, an increase of the prevalence of bacterial r-strategists was noted at 7 days followed by a decline at 60 days, which also hinted at the effectiveness of the fumigation treatments The survival of a non-toxigenic Escherichia coli O157:H7 derivative, strain T, was then assessed over 60 days in these microcosms, using detection via colony forming units counts as well as via PCR-DGGE Both data sets were consistent with each other Thus, a clear effect of fumigation depth on the survival of the invading strain T was noted, as a progressive increase of depth coincided with a progressively enhanced inoculant survival rate As fumigation depth was presumably inversely related to community complexity, this was consistent with the hypothesis that soil systems with reduced biological complexity offer enhanced opportunities for invading microbial species to establish and persist The significance of this finding is discussed in the light of the ongoing discussion about the complexity-invasiveness relationship within microbial communities, in particular regarding the opportunities of pathogens to persist

87 citations

Journal ArticleDOI
TL;DR: In this article, a search for the standard model Higgs boson produced in association with a top-quark pair is presented using data samples corresponding to an integrated luminosity of 5.0 fb−1 (5.1 fb −1) collected in pp collisions at the center-of-mass energy of 7 TeV (8 TeV).
Abstract: A search for the standard model Higgs boson produced in association with a top-quark pair is presented using data samples corresponding to an integrated luminosity of 5.0 fb−1 (5.1 fb−1) collected in pp collisions at the center-of-mass energy of 7 TeV (8 TeV). Events are considered where the top-quark pair decays to either one lepton+jets (tt−→lνqq−′bb−) or dileptons (tt−→l+νl−ν−bb−) , l being an electron or a muon. The search is optimized for the decay mode H→bb− . The largest background to the tt−H signal is top-quark pair production with additional jets. Artificial neural networks are used to discriminate between signal and background events. Combining the results from the 7 TeV and 8 TeV samples, the observed (expected) limit on the cross section for Higgs boson production in association with top-quark pairs for a Higgs boson mass of 125 GeV is 5.8 (5.2) times the standard model expectation.

87 citations

Journal ArticleDOI
TL;DR: In this paper, a search for new physics in final states containing a photon and missing transverse momentum was conducted at the LHC, and the first limits on dark matter production were found and significantly extended previous limits from LEP and the Tevatron.

87 citations

Journal ArticleDOI
TL;DR: The total phycobiliprotein content was extremely high, more than 30% of the dry algal biomass, thus the cyanobacterium could be deemed an alternative producer of C-phycocyanin.
Abstract: The effect of light intensity (50–300 μmol photons m−2 s−1) and temperature (15–50°C) on chlorophyll a, carotenoid and phycobiliprotein content in Arthronema africanum biomass was studied Maximum growth rate was measured at 300 μmol photons m−2 s−1 and 36°C after 96 h of cultivation The chlorophyll a content increased along with the increase in light intensity and temperature and reached 24% of dry weight at 150 μmol photons m−2 s−1 and 36°C, but it decreased at higher temperatures The level of carotenoids did not change significantly under temperature changes at illumination of 50 and 100 μmol photons m−2 s−1 Carotenoids were about 1% of the dry weight at higher light intensities: 150 and 300 μmol photons m−2 s−1 Arthronema africanum contained C-phycocyanin and allophycocyanin but no phycoerythrin The total phycobiliprotein content was extremely high, more than 30% of the dry algal biomass, thus the cyanobacterium could be deemed an alternative producer of C-phycocyanin A highest total of phycobiliproteins was reached at light intensity of 150 μmol photons m−2 s−1 and temperature of 36°C, C-phycocyanin and allophycocyanin amounting, respectively, to 23% and 12% of the dry algal biomass Extremely low ( 47°C) decreased phycobiliprotein content regardless of light intensity

87 citations

Journal ArticleDOI
S. Chatrchyan1, Vardan Khachatryan1, Albert M. Sirunyan1, Armen Tumasyan1  +3944 moreInstitutions (144)
TL;DR: A measurement of W+W- production in pp collisions at sqrt(s) = 7 TeV is presented in this paper, where the data were collected with the CMS detector at the LHC, and correspond to an integrated luminosity of 4.92 +/- 0.11 inverse femtobarns.
Abstract: A measurement of W+W- production in pp collisions at sqrt(s) = 7 TeV is presented. The data were collected with the CMS detector at the LHC, and correspond to an integrated luminosity of 4.92 +/- 0.11 inverse femtobarns. The W+W- candidates consist of two oppositely charged leptons, electrons or muons, accompanied by large missing transverse energy. The W+W- production cross section is measured to be 52.4 +/- 2.0 (stat.) +/- 4.5 (syst.) +/- 1.2 (lum.) pb. This measurement is consistent with the standard model prediction of 47.0 +/- 2.0 pb at next-to-leading order. Stringent limits on the WW gamma and WWZ anomalous triple gauge-boson couplings are set.

87 citations


Authors

Showing all 8600 results

NameH-indexPapersCitations
Michael Tytgat134144994133
Leander Litov133142492713
Eric Conte132120684593
Georgi Sultanov132149393318
Plamen Iaydjiev131128587958
Anton Dimitrov130123686919
Jordan Damgov129119585490
Borislav Pavlov129124586458
Jean-Laurent Agram128122184423
Cristina Botta128116079070
Jean-Charles Fontaine128119084011
Peicho Petkov128111183495
Muhammad Ahmad128118779758
Roumyana Hadjiiska126100373091
Mircho Rodozov12497270519
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202326
2022141
2021792
2020771
2019769
2018693