4,630 research outputs found
Angle-resolved photoemission study of insulating and metallic Cu-O chains in PrBaCuO and PrBaCuO
We compare the angle-resolved photoemission spectra of the hole-doped Cu-O
chains in PrBaCuO (Pr123) and in PrBaCuO (Pr124).
While, in Pr123, a dispersive feature from the chain takes a band maximum at
(momentum along the chain) and loses its spectral weight
around the Fermi level, it reaches the Fermi level at in
Pr124. Although the chains in Pr123 and Pr124 are approximately 1/4-filled,
they show contrasting behaviors: While the chains in Pr123 have an instability
to charge ordering, those in Pr124 avoid it and show an interesting spectral
feature of a metallic coupled-chain system.Comment: 4 pages, 5 figures, to be published in PR
How Sensitive Are Our Eyes to Text Difficulty? : Application of Schema Fixation Curves to Japanese Text
This paper discusses the applicability of Schema Fixation Curves to the detection of changes in the behavior of eye movements in accordance with the readability of text. If the eyes are to respond to the degree of difficulty of the given task, we may say that the eyes are an output device of our cognitive activities. Our previous research led us to the notation of Schema Fixation and Schema Fixation Curves, a technique with which graphically analyze the cognitive load the subjects bear when they read texts. The results of our experiments based on this technique show that the eye movement records are a good clue to the detection of text difficulty or readability of texts. Conventionally, computer-calculated readability indices have been used to predict text readability, but the precision of the prediction may not necessarily be so high. This is because most of these indices use syntactic elements of text such as average sentence length and word length. Difficulty of texts arises from a variety of factors, such as the reader\u27s background knowledge of the passage, the range of vocabulary used in the text, syntactic and semantic ambiguities, etc. In this experiment, we used the Japanese language in order to focus on syntactic effect on readability. Japanese allows much freer syntactic structure than present-day English. For example, the natural, normal, and unstressed word order of English (from amongst the six logical possibilities, SVO, SOV, VSO, VOS, OSV, OVS) is SVO while various combinations are both possible and natural in Japanese. We changed the syntactic order of words in sentences and presented them to the subjects in order to examine the recorded eye movements, and found that different orders produced different levels of readability
Acute WNT signalling activation perturbs differentiation within the adult stomach and rapidly leads to tumour formation
A role for WNT signalling in gastric carcinogenesis has been suggested due to two major observations. First, patients with germline mutations in adenomatous polyposis coli (APC) are susceptible to stomach polyps and second, in gastric cancer, WNT activation confers a poor prognosis. However, the functional significance of deregulated WNT signalling in gastric homoeostasis and cancer is still unclear. In this study we have addressed this by investigating the immediate effects of WNT signalling activation within the stomach epithelium. We have specifically activated the WNT signalling pathway within the mouse adult gastric epithelium via deletion of either glycogen synthase kinase 3 (GSK3) or APC or via expression of a constitutively active β-catenin protein. WNT pathway deregulation dramatically affects stomach homoeostasis at very short latencies. In the corpus, there is rapid loss of parietal cells with fundic gland polyp (FGP) formation and adenomatous change, which are similar to those observed in familial adenomatous polyposis. In the antrum, adenomas occur from 4 days post-WNT activation. Taken together, these data show a pivotal role for WNT signalling in gastric homoeostasis, FGP formation and adenomagenesis. Loss of the parietal cell population and corresponding FGP formation, an early event in gastric carcinogenesis, as well as antral adenoma formation are immediate effects of nuclear β-catenin translocation and WNT target gene expression. Furthermore, our inducible murine model will permit a better understanding of the molecular changes required to drive tumourigenesis in the stomach
Observation of and search for in B decays
We report a study of and
decay modes using events collected at the
\Upsilon(4S)e^+ e^-X(3872) \to J/\psi \gamma\chi_{c2} \to J/\psi \gammaB\to (X_{c\bar{c}}\gamma) KX(3872) \to \psi' \gamma\mathcal{B}(B^{\pm} \to X(3872)
K^{\pm}) \mathcal{B}(X(3872) \to J/\psi\gamma)=(1.78^{+0.48}_{-0.44}\pm
0.12)\times 10^{-6}\mathcal{B} (B^{\pm} \to\chi_{c2} K^{\pm})=(1.11^{+0.36}_{-0.34} \pm 0.09) \times 10^{-5}\mathcal{B}(B^{\pm} \to
X(3872) K^{\pm}) \mathcal{B}(X(3872) \to \psi'\gamma)<3.45\times 10^{-6}$
(upper limit at 90% C.L.) and also provide upper limits for other searches.Comment: 6 pages, 3 figure
First Observation of Radiative B^0 -> \phi K^0 \gamma Decays and Measurements of Their Time-Dependent CP Violation
We report the first observation of the radiative decay B^0 -> \phi K^0 \gamma
using a data sample of 772 x 10^6 B B-bar pairs collected at the \Upsilon(4S)
resonance with the Belle detector at the KEKB asymmetric-energy e^+e^-
collider. We observe a signal of 37+/-8 events with a significance of 5.4
standard deviations including systematic uncertainties. The measured branching
fraction is , where the uncertainties are statistical and systematic, respectively.
We also report the first measurements of time-dependent CP violation
parameters: and . Furthermore, we measure , and find that the signal is concentrated in
the M_{\phi K} mass region near threshold.Comment: 6 pages, 3 figures, Modified version is to be published in PRD(RC
Measurement of the cross-section and charge asymmetry of bosons produced in proton-proton collisions at TeV with the ATLAS detector
This paper presents measurements of the and cross-sections and the associated charge asymmetry as a
function of the absolute pseudorapidity of the decay muon. The data were
collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with
the ATLAS experiment at the LHC and correspond to a total integrated luminosity
of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements
varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the
1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured
with an uncertainty between 0.002 and 0.003. The results are compared with
predictions based on next-to-next-to-leading-order calculations with various
parton distribution functions and have the sensitivity to discriminate between
them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables,
submitted to EPJC. All figures including auxiliary figures are available at
https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13
Performance de novilhas holandesas alimentadas com silagens de cana-de-açúcar tratadas com uréia, benzoato de sódio ou Lactobacillus Buchneri.
A fermentação alcoólica influencia negativamente a qualidade de silagens de cana-de-açúcar e pode prejudicar a performance dos animais. Alguns aditivos podem reduzir a produção de etanol e as perdas nessas silagens. Este experimento objetivou avaliar a performance de novilhas alimentadas com rações contendo silagens de cana-de-açúcar aditivadas ou sem tratamento. Trinta e duas novilhas Holandesas foram aleatoriamente distribuídas em um delineamento em blocos, para avaliar rações (46% silagem; 54% concentrado; 12% proteína bruta) contendo silagem sem aditivo (controle) ou silagens tratadas com (base matéria verde) uréia (0,5%), benzoato de sódio (0,1 %) ou "Lactobacillus buchneri" (3,64 x 10"5" ufc g"-1"). A inoculação com "Lactobacillus buchneri" melhorou (P < 0,01) o ganho diário (1,24 vs 0,94 kg/dia) e com o benzoato melhorou a conversão alimentar (7.6 vs 9,4 kg de matéria seca/kg de peso vivo). Os tratamentos não afetaram o consumo de matéria seca (2,19% do peso vivo, em média. O tratamento com uréia não tenha melhorou o desempenho dos animais. Concluiu-se que o tratamento com aditivos pode ser um método eficiente para obtenção de silagens de cana-de-açúcar de melhor valor nutritivo
Bounds on the width, mass difference and other properties of X(3872) --> pi+pi-J/psi decays
We present results from a study of X(3872) --> pi+pi- J/psi decays produced
via exclusive B--> K X(3872) decays. We determine the mass to be M_X(3872)=
(3871.84\pm 0.27 (stat)\pm 0.19 (syst)) MeV, a 90% CL upper limit on the
natural width of Gamma_X(3872)
K+X(3872))xBf(X(3872)-->pi+pi-J/psi)=(8.61 \pm 0.82(stat) \pm 0.52 (syst))
x10^{-6}, and a ratio of branching fractions Bf(B0--> K0 X(3872))/BF(B+--> K+
X(3872))=0.50\pm 0.14(stat)\pm0.04(syst). The difference in mass between the
X(3872)-->pi+pi-J/psi signals in B+ and B0 decays is Delta M_{X(3872)= (-0.69
\pm 0.97 (stat)} \pm 0.19 (syst)) MeV. A search for a charged partner of the
X(3872) in the decays Bbar0-->K- X+ or B+-->K0X+, X+-->pi+pi0 J/psi resulted in
upper limits on the product branching fractions for these processes that are
well below expectations for the case that the X(3872) is the neutral member of
an isospin triplet. In addition, we examine possible J^{PC} quantum number
assignments for the X(3872) based on comparisons of angular correlations
between final state particles in X(3872)-->pi+pi-J/psi decays with simulated
data for J^{PC} values of 1^{++} and 2^{-+}. We examine the influence of
rho-omega interference in the M(pi+pi-) spectrum. The analysis is based on a
711fb^{-1} data sample that contains 772 million BBbar meson pairs collected at
the Upsilon(4S) resonance in the Belle detector at the KEKB e+e- collider.Comment: 15 pages, 10 figures and 6 tables. Submitted to Physical Review
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