Northern Illinois University

About: Northern Illinois University is a education organization based out in DeKalb, Illinois, United States. It is known for research contribution in the topics: Large Hadron Collider & Population. The organization has 8818 authors who have published 20008 publications receiving 632341 citations. The organization is also known as: NIU.

Evidence for an anomalous like-sign dimuon charge asymmetry

Abstract: We measure the charge asymmetry A =(N++ -N--)/(N++ + N--) of like-sign dimuon events in 6.1 fb(-1) of p (p) over bar collisions recorded with the D0 detector at a center-of-mass energy root s = 1: 96 TeV at the Fermilab Tevatron collider. From A we extract the like-sign dimuon charge asymmetry in semileptonic b-hadron decays: A(sl)(b) = -0.009 57 +/- 0.00251(stat) +/- 0.001 46(sys). It differs by 3.2 standard deviations from the standard model prediction A(sl)(b)(SM) = (-2.3(-0.6)(+0.5)) x 10(-4), and provides first evidence of anomalous CP violation in the mixing of neutral B mesons.

A new porous three-dimensional lanthanide coordination polymer.

Abstract: The open-framework coordination polymer [Er(C9H9O6)(H2O)2]·2.5H2O (C9H9O6 = cis,cis-1,3,5-cyclohexanetricarboxylate) has been synthesized under hydrothermal conditions. Each Er ion is coordinated to nine oxygen atoms belonging to two water molecules and five carboxylate ligands. Its 3-D polymeric structure possesses channels containing the guest water molecules that can be removed to afford a porous material [Er(C9H9O6)(H2O)2]. The metal−organic framework in [Er(C9H9O6)(H2O)2] can withstand the removal of 1 equiv of coordinated water.

Search for the bb ¯ decay of the Standard Model Higgs boson in associated (W/Z)H production with the ATLAS detector

Abstract: A search for the b (b) over bar decay of the Standard Model Higgs boson is performed with the ATLAS experiment using the full dataset recorded at the LHC in Run 1. The integrated luminosities used are 4.7 and 20.3 fb(-1) from pp collisions at root s = 7 and 8 TeV, respectively. The processes considered are associated (WIZ)H production, where W -> e nu/mu nu, Z -> ee/mu mu, and Z -> nu nu. The observed (expected) deviation from the backgroundonly hypothesis corresponds to a significance of 1.4 (2.6) standard deviations and the ratio of the measured signal yield to the Standard Model expectation is found to be mu = 0.52 +/- 0.32 (stat.) +/- 0.24 (syst.) for a Higgs boson mass of 125.36 GeV. The analysis procedure is validated by a measurement of the yield of (W/Z)Z production with Z -> b (b) over bar in the same final states as for the Higgs boson search, from which the ratio of the observed signal yield to the Standard Model expectation is found to be 0.74 +/- 0.09 (stat.) +/- 0.14 (syst.).

Histidine 52 is a critical residue for rapid formation of cytochrome c peroxidase compound I.

Abstract: The crystal structure and reactivity with hydrogen peroxide are reported for a mutant of a cloned cytochrome c peroxidase [CcP(MI)], in which the conserved distal His (His-52) is replaced with Leu. The reaction of the H52L enzyme with peroxide was examined as a function of pH in 0.1 M phosphate buffers and buffers in which nitrate was used to adjust the ionic strength. The pH-independent bimolecular rate constant for the reaction of H52L with peroxide was 731 +/- 44 and 236 +/- 14 M-1 s-1 in phosphate and nitrate-containing buffers, respectively. This represents a 10(5)-fold decrease in rate relative to the CcP(MI) parent under comparable conditions. Single-crystal diffraction studies showed that no dramatic changes in the structure or in the accessibility of the heme binding site were caused by the mutation. Rather, the mutation caused significant structural changes only at residue 52 and the nearby active-site water molecules. The residual reactivity of the H52L enzyme with peroxide was pH- and buffer-dependent. In nitrate-containing buffer, the apparent bimolecular rate constant for the reaction with peroxide decreased with decreasing pH; the loss of reactivity correlated with protonation of a group with an apparent pKA = 4.5. Protonation of the group caused a loss of reactivity with peroxide. This is in contrast to the CcP(MI) parent enzyme, as well as all other mutants that have been examined, where the loss of reactivity correlates with protonation of an enzyme group with an apparent pKA = 5.4.(ABSTRACT TRUNCATED AT 250 WORDS)

Maternal responsive and directive behaviours and utterances as predictors of children's lexical development

Abstract: Predictive relations were examined between measures of 20 mothers' behavioural and verbal general and specific responsiveness and intrusive and supportive directiveness and their children's subsequent expressive vocabularies during three developmental periods with endpoints at the beginning, middle, and end of the second year: 0; 10 to 1; 1, 1 ; 1 to 1; 5, and 1;5 to 1;9. Regression analyses, controlling for mothers' utterance frequencies and children's initial lexicons, revealed considerable consistency between reported and observed lexicons but changing patterns of predictive relations with development. During the first period, behavioural, but not verbal, measures of maternal responsiveness and supportive directiveness were positively predictive. In period two, verbal, but not behavioural, measures predicted children's vocabularies, with specific responsiveness and supportive directiveness as positive predictors and intrusive directiveness as a negative predictor. During the final period, mothers' behavioural and verbal responsiveness and behavioural supportive directiveness positively predicted and their verbal intrusive directiveness negatively predicted children's lexical growth.