Angle-resolved photoemission study of insulating and metallic Cu-O chains in PrBa2_2Cu3_3O7_7 and PrBa2_2Cu4_4O8_8

We compare the angle-resolved photoemission spectra of the hole-doped Cu-O chains in PrBa$_2$Cu$_3$O$_7$ (Pr123) and in PrBa$_2$Cu$_4$O$_8$ (Pr124). While, in Pr123, a dispersive feature from the chain takes a band maximum at $k_b$ (momentum along the chain) $\sim$ $\pi/4$ and loses its spectral weight around the Fermi level, it reaches the Fermi level at $k_b$ $\sim$ $\pi/4$ 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

Influence of pulsed laser deposition growth conditions on the thermoelectric properties of Ca3Co4O9 thin films

Thin films of the misfit cobaltite Ca3Co4O9 were grown on (0001)-oriented (c-cut) sapphire substrates, using the pulsed-laser deposition techniques. The dependence of the thermoelectric/transport properties on the film growth conditions was investigatedComment: To be published in J. Appl. Phy

Asymmetric total synthesis of (+)-virosine a via sequential nucleophilic cyclizations onto an activated formamide

Abstract: The first synthesis of tetracyclic alkaloid virosine A is reported. The natural alkaloid was prepared in only 13 steps, in an enantioenriched form. The azabicyclo[2.2.2]octane core was efficiently assembled using a key Vilsmeier–Haack and Mannich cyclizations sequence performed in one pot

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

First study of \eta_c, \eta(1760) and X(1835) production via \eta'\pi^+\pi^- final states in two-photon collisions

The invariant mass spectrum of the \eta' \pi^+ \pi^- final state produced in two-photon collisions is obtained using a 673 fb^{-1} data sample collected in the vicinity of the \Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e^+e^- collider. We observe a clear signal of the \eta_c and measure its mass and width to be M(\eta_c)=(2982.7 +- 1.8(stat) +- 2.2(syst) +- 0.3(model)) MeV/c^2 and \Gamma(\eta_c) = (37.8^{+5.8}_{-5.3}(stat) +- 2.8(syst) +- 1.4(model)) MeV/c^2. The third error is an uncertainty due to possible interference between the \eta_c and a non-resonant component. We also report the first evidence for \eta(1760) decay to \eta' \pi^+ \pi^-; we find two solutions for its parameters, depending on the inclusion or not of the X(1835), whose existence is of marginal significance in our data. From a fit to the mass spectrum using coherent X(1835) and \eta(1760) resonant amplitudes, we set a 90% confidence level upper limit on the product \Gamma_{\gamma\gamma} \BR (\eta' \pi^+ \pi^-) for the X(1835).Comment: 13 pages, 7 figures, submitted to PR

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 X(3872)→J/ψγX(3872)\to J/\psi \gamma and search for X(3872)→ψ′γX(3872)\to\psi'\gamma in B decays

We report a study of $B\to (J/\psi \gamma) K$ and $B\to (\psi' \gamma)K$ decay modes using $772\times 10^{6}$ $B\bar{B}$ events collected at the \Upsilon(4S)$resonance with the Belle detector at the KEKB energy-asymmetric$e^+ e^-$collider. We observe$X(3872) \to J/\psi \gamma$and report the first evidence for$\chi_{c2} \to J/\psi \gamma$in$B\to (X_{c\bar{c}}\gamma) K$decays, while in a search for$X(3872) \to \psi' \gamma$no significant signal is found. We measure the branching fractions,$\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