1,705 research outputs found

    Biology of Hymenosoma orbiculare Desm in Lake Sibaya

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    Hymenosoma orbiculare, (Crustacea: Brachyura: Hymenosomatidae) a crab common in estuaries in south- and south east Africa occurs in freshwater in Lake Sibaya at depths down to 40 m. This is the only known freshwater record of this species. The population density in the lake is fairly uniform declining in shallow and very deep water with an a11erage- of 2,5 m-2 (134 Jm-2). The proportion of females in the population increases with depth. Females carry fewer eggs than estuarine populations and breeding appears to occur throughout the year. Both zoeae and adults differ morphologically from estuarine populations. These differences in breeding, biology and morphology raise the possibility that the Lake Sibaya population is specifically distinct from estuarine populations and this is discussed in relation to other instances of hymenosomatid invasion of freshwater habitats.Hymenosoma orbiculare, (Crustacea: Brachyura: Hymenosomatidae) 'n krap wat algemeen voorkom in riviermondings in suid en suidoos Afrika, word ook aangetref in die varswater van die Sibayameer tot op 'n diepte van 40 m. Dit is die enigste bekende geval van hierdie spesie se voorkoms in varswater. Die populasiedigtheid is redelik eenvormig en neem af vanaf vlak tot baie diep water met 'n gemiddeld van 2,5 m-2 (134 Jm -2). Die verhouding van wyfies tot mannetjies neem toe met toename in diepte. Wyfies dra minder eiers as die in riviermondings en voortplanting vind blykbaar dwarsdeur die jaar plaas. Seide die zoeae en volwassenes verskil morfologies van die in riviermondings. Hierdie verskille in teling, biologie en morfologie dui op 'n moontlike spesieverskil tussen die bevolking in die Sibayameer en die in riviermondings. Hierdie aspekte word bespreek in die lig van ander gevalle van toetreding tot varswaterhabitatte onder die Hymenosomatidae

    RESPOND – A patient-centred program to prevent secondary falls in older people presenting to the emergency department with a fall: Protocol for a multi-centre randomised controlled trial

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    Introduction: Participation in falls prevention activities by older people following presentation to the Emergency Department (ED) with a fall is suboptimal. This randomised controlled trial (RCT) will test the RESPOND program which is designed to improve older persons’ participation in falls prevention activities through delivery of patient-centred education and behaviour change strategies. Design and setting: An RCT at two tertiary referral EDs in Melbourne and Perth, Australia. Participants: Five-hundred and twenty eight community-dwelling people aged 60-90 years presenting to the ED with a fall and discharged home will be recruited. People who: require an interpreter or hands-on assistance to walk; live in residential aged care or >50 kilometres from the trial hospital; have terminal illness, cognitive impairment, documented aggressive behaviour or history of psychosis; are receiving palliative care; or are unable to use a telephone will be excluded. Methods: Participants will be randomly allocated to the RESPOND intervention or standard care control group. RESPOND incorporates: (1) home-based risk factor assessment; (2) education, coaching, goal setting, and follow-up telephone support for management of one or more of four risk factors with evidence of effective intervention; and (3) healthcare provider communication and community linkage delivered over six months. Primary outcomes are falls and fall injuries per-person-year. Discussion: RESPOND builds on prior falls prevention learnings and aims to help individuals make guided decisions about how they will manage their falls risk. Patient-centred models have been successfully trialled in chronic and cardiovascular disease however evidence to support this approach in falls prevention is limited. Trial registration. The protocol for this study is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12614000336684)

    β-Catenin is a pH sensor with decreased stability at higher intracellular pH.

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    β-Catenin functions as an adherens junction protein for cell-cell adhesion and as a signaling protein. β-catenin function is dependent on its stability, which is regulated by protein-protein interactions that stabilize β-catenin or target it for proteasome-mediated degradation. In this study, we show that β-catenin stability is regulated by intracellular pH (pHi) dynamics, with decreased stability at higher pHi in both mammalian cells and Drosophila melanogaster β-Catenin degradation requires phosphorylation of N-terminal residues for recognition by the E3 ligase β-TrCP. While β-catenin phosphorylation was pH independent, higher pHi induced increased β-TrCP binding and decreased β-catenin stability. An evolutionarily conserved histidine in β-catenin (found in the β-TrCP DSGIHS destruction motif) is required for pH-dependent binding to β-TrCP. Expressing a cancer-associated H36R-β-catenin mutant in the Drosophila eye was sufficient to induce Wnt signaling and produced pronounced tumors not seen with other oncogenic β-catenin alleles. We identify pHi dynamics as a previously unrecognized regulator of β-catenin stability, functioning in coincidence with phosphorylation

    FUSE Measurements of Far Ultraviolet Extinction. I. Galactic Sight Lines

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    We present extinction curves that include data down to far ultraviolet wavelengths (FUV; 1050 - 1200 A) for nine Galactic sight lines. The FUV extinction was measured using data from the Far Ultraviolet Spectroscopic Explorer. The sight lines were chosen for their unusual extinction properties in the infrared through the ultraviolet; that they probe a wide range of dust environments is evidenced by the large spread in their measured ratios of total-to-selective extinction, R_V = 2.43 - 3.81. We find that extrapolation of the Fitzpatrick & Massa relationship from the ultraviolet appears to be a good predictor of the FUV extinction behavior. We find that predictions of the FUV extinction based upon the Cardelli, Clayton & Mathis (CCM) dependence on R_V give mixed results. For the seven extinction curves well represented by CCM in the infrared through ultraviolet, the FUV extinction is well predicted in three sight lines, over-predicted in two sight lines, and under-predicted in 2 sight lines. A Maximum Entropy Method analysis using a simple three component grain model shows that seven of the nine sight lines in the study require a larger fraction of grain materials to be in dust when FUV extinction is included in the models. Most of the added grain material is in the form of small (radii < 200 A) grains.Comment: Accepted for publication in the Astrophysical Journal. 31 pages with 7 figure

    T cell responses induced by adenoviral vectored vaccines can be adjuvanted by fusion of antigen to the oligomerization domain of C4b-binding protein.

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    Viral vectored vaccines have been shown to induce both T cell and antibody responses in animals and humans. However, the induction of even higher level T cell responses may be crucial in achieving vaccine efficacy against difficult disease targets, especially in humans. Here we investigate the oligomerization domain of the α-chain of C4b-binding protein (C4 bp) as a candidate T cell "molecular adjuvant" when fused to malaria antigens expressed by human adenovirus serotype 5 (AdHu5) vectored vaccines in BALB/c mice. We demonstrate that i) C-terminal fusion of an oligomerization domain can enhance the quantity of antigen-specific CD4(+) and CD8(+) T cell responses induced in mice after only a single immunization of recombinant AdHu5, and that the T cells maintain similar functional cytokine profiles; ii) an adjuvant effect is observed for AdHu5 vectors expressing either the 42 kDa C-terminal domain of Plasmodium yoelii merozoite surface protein 1 (PyMSP1(42)) or the 83 kDa ectodomain of P. falciparum strain 3D7 apical membrane antigen 1 (PfAMA1), but not a candidate 128kDa P. falciparum MSP1 biallelic fusion antigen; iii) following two homologous immunizations of AdHu5 vaccines, antigen-specific T cell responses are further enhanced, however, in both BALB/c mice and New Zealand White rabbits no enhancement of functional antibody responses is observed; and iv) that the T cell adjuvant activity of C4 bp is not dependent on a functional Fc-receptor γ-chain in the host, but is associated with the oligomerization of small (<80 kDa) antigens expressed by recombinant AdHu5. The oligomerization domain of C4 bp can thus adjuvant T cell responses induced by AdHu5 vectors against selected antigens and its clinical utility as well as mechanism of action warrant further investigation

    Prospects for Gene lntrogression from Hordeum bulbosum L. into Barley (H. vulgare L.).

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    Hybridizations between Hordeum vulgare L. (cultivated barley) and H. bulbosum L. have been performed over many years with two aims. First, the production of doubled haploid barley cultivars (Kasha and Kao 1970); second, the transfer of desirable traits such as resistance to fungal and viral pathogens from the wild species into barley. Apart from the report of an occasional recombinant (Xu and Kasha 1992; Pickering et al 1994), successful gene introgression has been hampered by several barriers. In this report we will describe recent progress in overcoming these barriers

    Anomalous Microwave Emission from the HII region RCW175

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    We present evidence for anomalous microwave emission in the RCW175 \hii region. Motivated by 33 GHz 13\arcmin resolution data from the Very Small Array (VSA), we observed RCW175 at 31 GHz with the Cosmic Background Imager (CBI) at a resolution of 4\arcmin. The region consists of two distinct components, G29.0-0.6 and G29.1-0.7, which are detected at high signal-to-noise ratio. The integrated flux density is 5.97±0.305.97\pm0.30 Jy at 31 GHz, in good agreement with the VSA. The 31 GHz flux density is 3.28±0.383.28\pm0.38 Jy (8.6σ8.6\sigma) above the expected value from optically thin free-free emission based on lower frequency radio data and thermal dust constrained by IRAS and WMAP data. Conventional emission mechanisms such as optically thick emission from ultracompact \hii regions cannot easily account for this excess. We interpret the excess as evidence for electric dipole emission from small spinning dust grains, which does provide an adequate fit to the data.Comment: 5 pages, 2 figures, submmited to ApJ Letter

    Confidence-based Optimization for the Newsvendor Problem

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    We introduce a novel strategy to address the issue of demand estimation in single-item single-period stochastic inventory optimisation problems. Our strategy analytically combines confidence interval analysis and inventory optimisation. We assume that the decision maker is given a set of past demand samples and we employ confidence interval analysis in order to identify a range of candidate order quantities that, with prescribed confidence probability, includes the real optimal order quantity for the underlying stochastic demand process with unknown stationary parameter(s). In addition, for each candidate order quantity that is identified, our approach can produce an upper and a lower bound for the associated cost. We apply our novel approach to three demand distribution in the exponential family: binomial, Poisson, and exponential. For two of these distributions we also discuss the extension to the case of unobserved lost sales. Numerical examples are presented in which we show how our approach complements existing frequentist - e.g. based on maximum likelihood estimators - or Bayesian strategies.Comment: Working draf

    Will the US Economy Recover in 2010? A Minimal Spanning Tree Study

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    We calculated the cross correlations between the half-hourly times series of the ten Dow Jones US economic sectors over the period February 2000 to August 2008, the two-year intervals 2002--2003, 2004--2005, 2008--2009, and also over 11 segments within the present financial crisis, to construct minimal spanning trees (MSTs) of the US economy at the sector level. In all MSTs, a core-fringe structure is found, with consumer goods, consumer services, and the industrials consistently making up the core, and basic materials, oil and gas, healthcare, telecommunications, and utilities residing predominantly on the fringe. More importantly, we find that the MSTs can be classified into two distinct, statistically robust, topologies: (i) star-like, with the industrials at the center, associated with low-volatility economic growth; and (ii) chain-like, associated with high-volatility economic crisis. Finally, we present statistical evidence, based on the emergence of a star-like MST in Sep 2009, and the MST staying robustly star-like throughout the Greek Debt Crisis, that the US economy is on track to a recovery.Comment: elsarticle class, includes amsmath.sty, graphicx.sty and url.sty. 68 pages, 16 figures, 8 tables. Abridged version of the manuscript presented at the Econophysics Colloquim 2010, incorporating reviewer comment

    VLT-UVES abundance analysis of four giants in NGC 6553

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    Metal-rich globular clusters trace the formation of bulges. Abundance ratios in the metal-rich globular clusters such as NGC 6553 can constrain the formation timescale of the Galactic bulge. The purpose of this study is determine the metallicity and elemental ratios in individual stars of the metal-rich bulge globular cluster NGC 6553. A detailed abundance analysis of four giants in NGC 6553 is carried out, based on optical high-resolution echelle spectra obtained with UVES at the ESO VLT-UT2 Kueyen telescope. A metallicity [Fe/H]= -0.20 dex is derived, together with α\alpha-element enhancement of Mg and Si ([Mg/Fe]=+0.28, [Si/Fe]=+0.21), solar Ca and Ti ([Ca/Fe]=+0.05, [Ti/Fe]=-0.01), and a mild enhancement of the r-process element Eu with [Eu/Fe] = +0.10. A mean heliocentric radial velocity of -1.86 km s−1^{-1} is measured. We compare our results with previous investigations of the cluster.Comment: 15 pages, 8 figures, A&A, in pres
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