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

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

Anti-inflammatory and anti-amyloidogenic effects of a small molecule, 2,4-bis(p-hydroxyphenyl)-2-butenal in Tg2576 Alzheimer’s disease mice model

<p>Abstract</p> <p>Background</p> <p>Alzheimer’s disease (AD) is pathologically characterized by excessive accumulation of amyloid-beta (Aβ) fibrils within the brain and activation of astrocytes and microglial cells. In this study, we examined anti-inflammatory and anti-amyloidogenic effects of 2,4-bis(p-hydroxyphenyl)-2-butenal (HPB242), an anti-inflammatory compound produced by the tyrosine-fructose Maillard reaction.</p> <p>Methods</p> <p>12-month-old Tg2576 mice were treated with HPB242 (5 mg/kg) for 1 month and then cognitive function was assessed by the Morris water maze test and passive avoidance test. In addition, western blot analysis, Gel electromobility shift assay, immunostaining, immunofluorescence staining, ELISA and enzyme activity assays were used to examine the degree of Aβ deposition in the brains of Tg2576 mice. The Morris water maze task was analyzed using two-way ANOVA with repeated measures. Otherwise were analyzed by one-way ANOVA followed by Dunnett’s post hoc test.</p> <p>Results</p> <p>Treatment of HPB242 (5 mg/kg for 1 month) significantly attenuated cognitive impairments in Tg2576 transgenic mice. HPB242 also prevented amyloidogenesis in Tg2576 transgenic mice brains. This can be evidenced by Aβ accumulation, BACE1, APP and C99 expression and β-secretase activity. In addition, HPB242 suppresses the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) as well as activation of astrocytes and microglial cells. Furthermore, activation of nuclear factor-kappaB (NF-κB) and signal transducer and activator of transcription 1/3 (STAT1/3) in the brain was potently inhibited by HPB242.</p> <p>Conclusions</p> <p>Thus, these results suggest that HPB242 might be useful to intervene in development or progression of neurodegeneration in AD through its anti-inflammatory and anti-amyloidogenic effects.</p

Transcriptomic analysis of grain amaranth (<it>Amaranthus hypochondriacus</it>) using 454 pyrosequencing: comparison with <it>A. tuberculatus</it>, expression profiling in stems and in response to biotic and abiotic stress

<p>Abstract</p> <p>Background</p> <p><it>Amaranthus hypochondriacus</it>, a grain amaranth, is a C4 plant noted by its ability to tolerate stressful conditions and produce highly nutritious seeds. These possess an optimal amino acid balance and constitute a rich source of health-promoting peptides. Although several recent studies, mostly involving subtractive hybridization strategies, have contributed to increase the relatively low number of grain amaranth expressed sequence tags (ESTs), transcriptomic information of this species remains limited, particularly regarding tissue-specific and biotic stress-related genes. Thus, a large scale transcriptome analysis was performed to generate stem- and (a)biotic stress-responsive gene expression profiles in grain amaranth.</p> <p>Results</p> <p>A total of 2,700,168 raw reads were obtained from six 454 pyrosequencing runs, which were assembled into 21,207 high quality sequences (20,408 isotigs + 799 contigs). The average sequence length was 1,064 bp and 930 bp for isotigs and contigs, respectively. Only 5,113 singletons were recovered after quality control. Contigs/isotigs were further incorporated into 15,667 isogroups. All unique sequences were queried against the nr, TAIR, UniRef100, UniRef50 and Amaranthaceae EST databases for annotation. Functional GO annotation was performed with all contigs/isotigs that produced significant hits with the TAIR database. Only 8,260 sequences were found to be homologous when the transcriptomes of <it>A. tuberculatus </it>and <it>A. hypochondriacus </it>were compared, most of which were associated with basic house-keeping processes. Digital expression analysis identified 1,971 differentially expressed genes in response to at least one of four stress treatments tested. These included several multiple-stress-inducible genes that could represent potential candidates for use in the engineering of stress-resistant plants. The transcriptomic data generated from pigmented stems shared similarity with findings reported in developing stems of Arabidopsis and black cottonwood (<it>Populus trichocarpa</it>).</p> <p>Conclusions</p> <p>This study represents the first large-scale transcriptomic analysis of <it>A. hypochondriacus</it>, considered to be a highly nutritious and stress-tolerant crop. Numerous genes were found to be induced in response to (a)biotic stress, many of which could further the understanding of the mechanisms that contribute to multiple stress-resistance in plants, a trait that has potential biotechnological applications in agriculture.</p