342 research outputs found

    Rectangle--triangle soft-matter quasicrystals with hexagonal symmetry

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    Aperiodic (quasicrystalline) tilings, such as Penrose's tiling, can be built up from e.g. kites and darts, squares and equilateral triangles, rhombi or shield shaped tiles and can have a variety of different symmetries. However, almost all quasicrystals occurring in soft-matter are of the dodecagonal type. Here, we investigate a class of aperiodic tilings with hexagonal symmetry that are based on rectangles and two types of equilateral triangles. We show how to design soft-matter systems of particles interacting via pair potentials containing two length-scales that form aperiodic stable states with two different examples of rectangle--triangle tilings. One of these is the bronze-mean tiling, while the other is a generalization. Our work points to how more general (beyond dodecagonal) quasicrystals can be designed in soft-matter.Comment: 15 pages, 13 figures. Submitted to Physical Review E. The data associated with this paper are openly available from the University of Leeds Data Repository at https://doi.org/10.5518/118

    Nobeyama 45-m CO J=1-0 Observations of Luminous Type 1 AGNs at z0.3z\approx0.3

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    We have performed CO J =1-0 observations of ten galaxies hosting luminous (Lbol>1046ergs1L_{\rm bol} > 10^{46}\,{\rm erg\,s^{-1}}) type 1 active galactic nuclei (AGNs) with the Nobeyama 45-m radio telescope. The targets are selected because they are expected to be rich in molecular gas based on their high nebular dust extinction (AVA_{\rm V}). However, no significant CO emission lines were detected in any of the targets. The upper limits of the CO J=1-0 luminosities are lower than expected given the molecular gas mass inferred from the nebular AVA_{\rm V}. This inconsistency may be due to overestimated AVA_{\rm V} values due to the lack of stellar absorption correction. Considering more reliable AVA_{\rm V} values, the CO J=1-0 non-detections by Nobeyama 45-m are natural. This suggests that our results do not contradict the conversion methods from AVA_{\rm V} to molecular gas mass proposed in the literature. This survey suggests that careful AVA_{\rm V} measurements as well as CO observations are still needed to improve the measurements or estimates of the molecular gas content of galaxies hosting luminous AGNs.Comment: 8 pages, 6 figures, Accepted for publication in PAS

    Monitoring serum IL-18 levels is useful for treatment of a patient with systemic juvenile idiopathic arthritis complicated by macrophage activation syndrome

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    Systemic juvenile idiopathic arthritis (sJIA) is a systemic inflammatory disease characterized by arthritis, spiking fever and a skin rash that is frequently complicated by macrophage activation syndrome (MAS), a life-threatening disorder. We report a 22-month-old girl with sJIA who developed severe MAS but was successfully treated with corticosteroids, cyclosporin A, and non-steroidal anti-inflammatory drugs by monitoring serum IL-18 levels. IL-18 is an extremely useful cytokine for monitoring the activity of sJIA and MAS, and serum IL-18 can be used as an indicator for the effectiveness of treatment and the decision to discontinue therapy.ArticlePEDIATRIC RHEUMATOLOGY. 9:15 (2011)journal articl

    Measurement of the branching fractions of the radiative leptonic τ decays τ→eγνν[bar] and τ→μγνν[bar] at BABAR

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    We perform a measurement of the τ→lγνν [bar] (l=e,μ) branching fractions for a minimum photon energy of 10 MeV in the τ rest frame, using 431  fb^(−1) of e^+ e^− collisions collected at the center-of-mass energy of the Υ(4S) resonance with the BABAR detector at the PEP-II storage rings. We find B(τ→μγνν [bar])=(3.69±0.03±0.10)×10^(−3) and B(τ→eγνν[bar]¯ )=(1.847±0.015±0.052)×10^(−2), where the first quoted error is statistical and the second is systematic. These results are substantially more precise than previous measurements

    Malignant Mesothelioma in the Thoracic Cavity of a Crj:CD(SD) Rat Characterized by Round Hyalinous Stroma

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    Spontaneous malignant mesothelioma was found in a 104-week-old male Crj:CD(SD) rat. The tumor was scattered on the surface of the lung, heart, mediastinal pleura and thoracic wall and metastasized to the alveolar septa. Histopathologically, small flattened or cuboidal tumor cells proliferated with stroma, formed almost normal papillary structures and reacted positively to colloidal iron stain and immunohistochemical staining for mesothelin. Round hyalinous stromata were pronounced, which is a characteristic feature, and the possible reason for this is as follows; at first, a small amount of collagen fibers was formed in the center of the clusters of several tumor cells, and then the cell clusters expanded like balloons with an increase in the collagen fibers

    The ALMaQUEST Survey XII: Dense Molecular Gas as traced by HCN and HCO+^{+} in Green Valley Galaxies

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    We present ALMA observations of two dense gas tracers, HCN(1-0) and HCO+^{+}(1-0), for three galaxies in the green valley and two galaxies on the star-forming main sequence with comparable molecular gas fractions as traced by the CO(1-0) emissions, selected from the ALMaQUEST survey. We investigate whether the deficit of molecular gas star formation efficiency (SFEmol_{\rm mol}) that leads to the low specific star formation rate in these green valley galaxies is due to a lack of dense gas (characterized by the dense gas fraction fdensef_{\rm dense}) or the low star formation efficiency of dense gas (SFEdense_{\rm dense}). We find that SFEmol_{\rm mol} as traced by the CO emissions, when considering both star-forming and retired spaxels together, is tightly correlated with SFEdense_{\rm dense} and depends only weakly on fdensef_{\rm dense}. The specific star formation rate (sSFR) on kpc scales is primarily driven by SFEmol_{\rm mol} and SFEdense_{\rm dense}, followed by the dependence on fmolf_{\rm mol}, and is least correlated with fdensef_{\rm dense} or the dense-to-stellar mass ratio (RdenseR_{\rm dense}). When compared with other works in the literature, we find that our green valley sample shows lower global SFEmol_{\rm mol} as well as lower SFEdense_{\rm dense} while exhibiting similar dense gas fractions when compared to star-forming and starburst galaxies. We conclude that the star formation of the 3 green valley galaxies with a normal abundance of molecular gas is suppressed mainly due to the reduced SFEdense_{\rm dense} rather than the lack of dense gas.Comment: 20 pages, 13 figures, ApJ accepte

    A high dust emissivity index beta for a CO-faint galaxy in a filamentary Lyman-alpha nebula at z=3.1

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    We present CO J=4-3 line and 3 mm dust continuum observations of a 100 kpc-scale filamentary Ly{\alpha} nebula (SSA22 LAB18) at z=3.1 using the Atacama Large Millimeter/submillimeter Array (ALMA). We detected the CO J=4-3 line at a systemic z(CO)=3.093 {\pm} 0.001 at 11 {\sigma} from one of the ALMA continuum sources associated with the Ly{\alpha} filament. We estimated the CO J=4-3 luminosity of L'CO(4-3)=(2.3\pm0.2)x10^9 K km s^{-1} pc^2 for this CO source, which is one order of magnitude smaller than those of typical z>1 dusty star-forming galaxies (DSFGs) of similar far-infrared luminosity L(IR)~10^{12} Lsun. We derived a molecular gas mass of Mgas=(4.4^{+0.9}_{-0.6})x10^9 Msun and a star-formation rate of SFR=270\pm160 Msun yr^{-1}. We also estimated a gas depletion time of {\tau}(dep)=17\pm10 Myr, being shorter than those of typical DSFGs. It is suggested that this source is in a transition phase from DSFG to a gas-poor, early-type galaxy. From ALMA to Herschel multi-band dust continuum observations, we measured a dust emissivity index {\beta}=2.3\pm0.2, which is similar to those of local gas-poor, early-type galaxies. Such a high {\beta} can be reproduced by specific chemical compositions for interstellar dust at the submillimeter wavelengths from recent laboratory experiments. ALMA CO and multi-band dust continuum observations can constrain the evolutionary stage of high-redshift galaxies through {\tau}(dep) and {\beta}, and thus we can investigate dust chemical compositions even in the early Universe.Comment: 6 pagers, 3 figure

    Evolution of Linear Absorption and Nonlinear Optical Properties in V-Shaped Ruthenium(II)-Based Chromophores

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    In this article, we describe a series of complexes with electron-rich cis-{Ru^(II)(NH_3)_4}^(2+) centers coordinated to two pyridyl ligands bearing N-methyl/arylpyridinium electron-acceptor groups. These V-shaped dipolar species are new, extended members of a class of chromophores first reported by us (Coe, B. J. et al. J. Am. Chem. Soc. 2005, 127, 4845−4859). They have been isolated as their PF_6− salts and characterized by using various techniques including ^1H NMR and electronic absorption spectroscopies and cyclic voltammetry. Reversible Ru^(III/II) waves show that the new complexes are potentially redox-switchable chromophores. Single crystal X-ray structures have been obtained for four complex salts; three of these crystallize noncentrosymmetrically, but with the individual molecular dipoles aligned largely antiparallel. Very large molecular first hyperpolarizabilities β have been determined by using hyper-Rayleigh scattering (HRS) with an 800 nm laser and also via Stark (electroabsorption) spectroscopic studies on the intense, visible d → π^* metal-to-ligand charge-transfer (MLCT) and π → π^* intraligand charge-transfer (ILCT) bands. The latter measurements afford total nonresonant β_0 responses as high as ca. 600 × 10^(−30) esu. These pseudo-C_(2v) chromophores show two substantial components of the β tensor, β_(zzz) and β_(zyy), although the relative significance of these varies with the physical method applied. According to HRS, β_(zzz) dominates in all cases, whereas the Stark analyses indicate that β_(zyy) is dominant in the shorter chromophores, but β_(zzz) and β_(zyy) are similar for the extended species. In contrast, finite field calculations predict that β_(zyy) is always the major component. Time-dependent density functional theory calculations predict increasing ILCT character for the nominally MLCT transitions and accompanying blue-shifts of the visible absorptions, as the ligand π-systems are extended. Such unusual behavior has also been observed with related 1D complexes (Coe, B. J. et al. J. Am. Chem. Soc. 2004, 126, 3880−3891)

    Components of smartphone cognitive-behavioural therapy for subthreshold depression among 1093 university students: a factorial trial

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    BACKGROUND: Internet-based cognitive-behavioural therapy (iCBT) is effective for subthreshold depression. However, which skills provided in iCBT packages are more effective than others is unclear. Such knowledge can inform construction of more effective and efficient iCBT programmes. OBJECTIVE: To examine the efficacy of five components of iCBT for subthreshold depression. METHODS: We conducted an factorial trial using a smartphone app, randomly allocating presence or absence of five iCBT skills including self-monitoring, behavioural activation (BA), cognitive restructuring (CR), assertiveness training (AT) and problem-solving. Participants were university students with subthreshold depression. The primary outcome was the change on the Patient Health Questionnaire-9 (PHQ-9) from baseline to week 8. Secondary outcomes included changes in CBT skills. FINDINGS: We randomised a total of 1093 participants. In all groups, participants had a significant PHQ-9 reduction from baseline to week 8. Depression reduction was not significantly different between presence or absence of any component, with corresponding standardised mean differences (negative values indicate specific efficacy in favour of the component) ranging between -0.04 (95% CI -0.16 to 0.08) for BA and 0.06 (95% CI -0.06 to 0.18) for AT. Specific CBT skill improvements were noted for CR and AT but not for the others. CONCLUSIONS: There was significant reduction in depression for all participants regardless of the presence and absence of the examined iCBT components. CLINICAL IMPLICATION: We cannot yet make evidence-based recommendations for specific iCBT components. We suggest that future iCBT optimisation research should scrutinise the amount and structure of components to examine. TRIAL REGISTRATION NUMBER: UMINCTR-000031307

    An International Quiet Ocean Experiment

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    Author Posting. © Oceanography Society, 2011. This article is posted here by permission of Oceanography Society for personal use, not for redistribution. The definitive version was published in Oceanography 24, no. 2 (2011): 174–181, doi:10.5670/oceanog.2011.37.The effect of noise on marine life is one of the big unknowns of current marine science. Considerable evidence exists that the human contribution to ocean noise has increased during the past few decades: human noise has become the dominant component of marine noise in some regions, and noise is directly correlated with the increasing industrialization of the ocean. Sound is an important factor in the lives of many marine organisms, and theory and increasing observations suggest that human noise could be approaching levels at which negative effects on marine life may be occurring. Certain species already show symptoms of the effects of sound. Although some of these effects are acute and rare, chronic sublethal effects may be more prevalent, but are difficult to measure. We need to identify the thresholds of such effects for different species and be in a position to predict how increasing anthropogenic sound will add to the effects. To achieve such predictive capabilities, the Scientific Committee on Oceanic Research (SCOR) and the Partnership for Observation of the Global Oceans (POGO) are developing an International Quiet Ocean Experiment (IQOE), with the objective of coordinating the international research community to both quantify the ocean soundscape and examine the functional relationship between sound and the viability of key marine organisms. SCOR and POGO will convene an open science meeting to gather community input on the important research, observations, and modeling activities that should be included in IQOE
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