15 research outputs found
Measurement of the cross-section for b-jets produced in association with a Z boson at root s=7 TeV with the ATLAS detector ATLAS Collaboration
A measurement is presented of the inclusive cross-section for b-jet production in association with a Z boson in pp collisions at a centre-of-mass energy of root s = 7 TeV. The analysis uses the data sample collected by the ATLAS experiment in 2010, corresponding to an integrated luminosity of approximately 36 pb(-1). The event selection requires a Z boson decaying into high P-T electrons or muons, and at least one b-jet, identified by its displaced vertex, with transverse momentum p(T) > 25 GeV and rapidity vertical bar y vertical bar < 2.1. After subtraction of background processes, the yield is extracted from the vertex mass distribution of the candidate b-jets. The ratio of this cross-section to the inclusive Z cross-section (the average number of b-jets per Z event) is also measured. Both results are found to be in good agreement with perturbative QCD predictions at next-to-leading order
Occurrence of Bifidobacteriaceae in herbivorous primate Theropithecus gelada
Primates in general exhibit a wide dietary diversity, enabling them to occupy various ecological
niches. It is well know that the diet greatly influences microbial diversity of gut microbiota and
generally, a fibre rich diet promotes the growth of microbial groups producing short fatty acids,
thus playing an important beneficial role in the host health. The Bifidobacteriaceae are grampositive,
pleomorphically branched, non-motile, non-spore-forming that constitute a significant
proportion of the microbiota in the gut. They can be grouped on the basis of one of six different
ecological niches that they occupy: the human intestine, oral cavity, food, the animal
gastrointestinal tract, the insect intestine, and sewage. Although nearly all primates are to some
extent omnivorous, most primates can be primarily categorized as fruit-, insect- or leaf-eaters.
However, in all primate diversity, there is only one species of modern primate that feeds on
particularly nutrient-poor plant material is the gelada baboon (Theropithecus gelada). Native to the
highlands of Ethiopia, they subsist largely as grazers, the only modern primate species to do so.
Aim of this work was to investigate the occurrence of Bifidobacteriaceae in six adult males of
Theropithecus gelada housed in Parco Natura Viva Garda Zoological Park (Bussolengo, Verona,
Italy). Different selective media were tested for their suitability in the isolation of the
Bifidobacteriaceae strains. All sixteen isolates were clones as resulted from BOX-PCR
fingerprinting, a technique allowing the molecular typing. Comparative analysis of the 16S rRNA
gene sequences revealed low sequence similarity of isolates to known Bifidobacteriaceae and the
highest similarity (96.1 %) was found to Alloscardovia criceti. Therefore the isolates are
phylogenetically not closely related to known species and are possible novel species in the genus
Alloscardovia of the Bifidobacteriaceae family. For the first time member of Bifidobacteriaceae
family have been found in Theropithecus gelada and further studies are needed to better analyse
the importance of their presence in these very peculiar group of monkeys