5,489 research outputs found

    "Austropop" : Stationen der Entwicklung einer nationalen Pop- und Rockmusik

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    Urban stormwater is a crucial resource at a time when climate change and population growth threaten freshwater supplies; but there are health risks from contaminants, such as toxic metals. It is vitally important to understand how to use this resource safely and responsibly. Our study investigated the extent of metal contamination in vegetable crops irrigated with stormwater under short- and long-term conditions. We created artificially aged gardens by adding metal-contaminated sediment to soil, simulating accumulation of metals in the soil from irrigation with raw stormwater over zero, five and ten years. Our crops--French bean (Phaseolus vulgaris), kale (Brassica oleracea var. acephala), and beetroot (Beta vulgaris)--were irrigated twice a week for 11 weeks, with either synthetic stormwater or potable water. They were then tested for concentrations of Cd, Cr, Pb, Cu and Zn. An accumulation of Pb was the most marked sign of contamination, with six of nine French bean and seven of nine beetroot leaf samples breaching Australia's existing guidelines. Metal concentration in a crop tended to increase with the effective age of the garden; but importantly, its rate of increase did not match the rate of increase in the soil. Our study also highlighted differences in sensitivity between different crop types. French bean demonstrated the highest levels of uptake, while kale displayed restrictive behaviour. Our study makes it clear: irrigation with stormwater is indeed feasible, as long as appropriate crops are selected and media are frequently turned over. We have also shown that an understanding of such risks yields meaningful information on appropriate safeguards. A holistic approach is needed--to account for all routes to toxic metal exposure, including especially Pb. A major outcome of our study is critical information for minimising health risks from stormwater irrigation of crops

    Counts and Colors of Faint Galaxies in the U and R Bands

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    Ground-based counts and colors of faint galaxies in the U and R bands in one field at high Galactic latitude are presented. Integrated over flux, a total of 1.2x10^5 sources per square degree are found to U=25.5 mag and 6.3x10^5 sources per square degree to R=27 mag, with d log N/dm ~ 0.5 in the U band and d log N/dm ~ 0.3 in the R band. Consistent with these number-magnitude curves, sources become bluer with increasing magnitude to median U-R=0.6 mag at 24<U<25 mag and U-R=1.2 mag at 25 < R < 26 mag. Because the Lyman break redshifts into the U band at z~3, at least 1.2x10^5 sources per square degree must be at redshifts z<3. Measurable U-band fluxes of 73 percent of the 6.3x10^5 sources per square degree suggest that the majority of these also lie at z < 3. These results require an enormous space density of objects in any cosmological model.Comment: 17 pages, MNRAS in pres

    Association between overall rate of change in rising breath alcohol concentration and the magnitude of acute tolerance of subjective intoxication via the Mellanby method

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    ObjectiveThe magnitude of acute tolerance is a strong predictor of the development of longerñ term chronic tolerance and plays a decisive role in risky decisions (e.g., driving after drinking). Therefore, it is important to identify factors that increase the magnitude of this adaptive process. This study explored whether acute tolerance magnitude varied as a function of the overall rate of increase in breath alcohol concentration (BrAC).MethodsTwentyñ nine young adult social drinkers (M age = 22.55, SD = 3.10; 62.1% women) consumed a moderate dose of alcohol (men: 0.86 g/kg, women: 0.75 g/kg) in a controlled laboratory setting. Subjective intoxication was assessed at matched BrACs (~0.060 g/dl) on each limb of the BrAC curve.ResultsHierarchical regression results indicated that faster overall increases in BrAC on the ascending limb were associated with greater acute tolerance for subjective intoxication ratings (p < .01, R2 = .29).ConclusionsThese results present some of the first evidence that faster increases in BrAC may be associated with greater acute tolerance, as indicated by greater reduction in subjective intoxication across the limbs of the BrAC curve. This greater reduction may, in turn, promote heavier drinking and/or engagement in behaviors for which one is unfit (e.g., driving after drinking).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135992/1/hup2565_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/135992/2/hup2565.pd

    Five Planets Orbiting 55 Cancri

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    We report 18 years of Doppler shift measurements of a nearby star, 55 Cancri, that exhibit strong evidence for five orbiting planets. The four previously reported planets are strongly confirmed here. A fifth planet is presented, with an apparent orbital period of 260 days, placing it 0.78 AU from the star in the large empty zone between two other planets. The velocity wobble amplitude of 4.9 \ms implies a minimum planet mass \msini = 45.7 \mearthe. The orbital eccentricity is consistent with a circular orbit, but modest eccentricity solutions give similar \chisq fits. All five planets reside in low eccentricity orbits, four having eccentricities under 0.1. The outermost planet orbits 5.8 AU from the star and has a minimum mass, \msini = 3.8 \mjupe, making it more massive than the inner four planets combined. Its orbital distance is the largest for an exoplanet with a well defined orbit. The innermost planet has a semi-major axis of only 0.038 AU and has a minimum mass, \msinie, of only 10.8 \mearthe, one of the lowest mass exoplanets known. The five known planets within 6 AU define a {\em minimum mass protoplanetary nebula} to compare with the classical minimum mass solar nebula. Numerical N-body simulations show this system of five planets to be dynamically stable and show that the planets with periods of 14.65 and 44.3 d are not in a mean-motion resonance. Millimagnitude photometry during 11 years reveals no brightness variations at any of the radial velocity periods, providing support for their interpretation as planetary.Comment: accepted to Ap

    CONSERVATION OF THE IRISH POPULATIONS OF THE POLLAN COREGONUS AUTUMNALIS

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    ABSTRACT The Irish lake populations of pollan Coregonus autumnalis Pallas are detached from other Arctic populations and exist at the southern extreme of the range of the species. They are landlocked relics of postglacial colonisation by anadromous forms. In Ireland, pollan exist in atypical habitats and temperature ranges for the species as a whole and are threatened with extinction by a range of potentially detrimental factors, including eutrophication and competition with introduced nonindigenous species. All but one of the four populations is critically endangered. This paper summarises current knowledge of pollan, the status of the four populations and actions proposed to protect and enhance the remaining stocks

    The optical/X-ray connection: ICM iron content and galaxy optical luminosity in 20 galaxy clusters

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    X-ray observations of galaxy clusters have shown that the intra-cluster gas has iron abundances of about one third of the solar value. These observations also show that part (if not all) of the intra-cluster gas metals were produced within the member galaxies. We present a systematic analysis of 20 galaxy clusters to explore the connection between the iron mass and the total luminosity of early-type and late-type galaxies, and of the brightest cluster galaxies (BCGs). From our results, the intra-cluster medium (ICM) iron mass seems to correlate better with the luminosity of the BCGs than with that of the red and blue galaxy populations. As the BCGs cannot produce alone the observed amount of iron, we suggest that ram-pressure plus tidal stripping act together to enhance, at the same time, the BCG luminosities and the iron mass in the ICM. Through the analysis of the iron yield, we have also estimated that SN Ia are responsible for more than 50% of the total iron in the ICM. This result corroborates the fact that ram-pressure contributes to the gas removal from galaxies to the inta-cluster medium, being very efficient for clusters in the temperature range 2 < kT (keV)< 10Comment: Accepted for publication in MNRAS (11 pg, 9 figures and 3 tables

    Gemini Deep Deep Survey VI: Massive Hdelta-strong galaxies at z=1

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    We show that there has been a dramatic decline in the abundance of massive galaxies with strong Hdelta stellar absorption lines from z=1.2 to the present. These ``Hdelta-strong'', or HDS, galaxies have undergone a recent and rapid break in their star-formation activity. Combining data from the Gemini Deep Deep and the Sloan Digital Sky Surveys to make mass-matched samples (M*>=10^10.2 Msun), with 25 and 50,255 galaxies, respectively), we find that the fraction of galaxies in an HDS phase has decreased from about 50% at z=1.2 to a few percent today. This decrease in fraction is due to an actual decrease in the number density of massive HDS systems by a factor of 2-4, coupled with an increase in the number density of massive galaxies by about 30 percent. We show that this result depends only weakly on the threshold chosen for the Hdelta equivalent width to define HDS systems (if greater than 4 A) and corresponds to a (1+z)^{2.5\pm 0.7} evolution. Spectral synthesis studies of the high-redshift population using the PEGASE code, treating Hdelta_A, EW[OII], Dn4000, and rest-frame colors, favor models in which the Balmer absorption features in massive Hdelta-strong systems are the echoes of intense episodes of star-formation that faded about 1 Gyr prior to the epoch of observation. The z=1.4-2 epoch appears to correspond to a time at which massive galaxies are in transition from a mode of sustained star formation to a relatively quiescent mode with weak and rare star-formation episodes. We argue that the most likely local descendants of the distant massive HDS galaxies are passively evolving massive galaxies in the field and small groups.Comment: 16 pages, 12 figures, 3 tables, uses emulateapj.sty; updated to match the version accepted by ApJ. One figure added, conclusions unchange

    Production of Heparin-Binding Epidermal Growth Factor–like Growth Factor (HB-EGF) at Sites of Thermal Injury in Pediatric Patients

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    Fluids that accumulate at wound sites may be an important reservoir of growth factors that promote the normal wound healing response. The presence of heparin-binding growth factors was studied in burn wound fluid (BWF) from 45 pediatric patients who had sustained partial thickness burns. One of the growth factors present was similar to platelet-derived growth factor (PDGF) based on its heparin affinity, inhibition of bioactivity by a PDGF antiserum, and detection in a PDGF-AB enzyme-linked iminunosorbent assay. A second growth factor was identified as heparin-binding epidermal growth factor–like growth factor (HB-EGF) based on its heparin affinity, competition with 125I-labeled epidermal growth factor (EGF) for EGF receptor binding, and recognition in biological assays and Western blots by two HB-EGF antisera. Amino acid sequence analysis of one form of this second growth factor verified its identity as an N-terminally truncated form of HB-EGF. Immunohistochemical analysis of partial thickness burns demonstrated the presence of HB-EGF in the advancing epithelial margin, islands of regenerating epithelium within the burn wound, and in the duct and proximal tubules of eccrine sweat glands. HB-EGF in the surface epithelium of burn wounds was uniformally distributed, whereas it was restricted to the basal epithelium in nonburned skin. These data support a role for PDGF and HB-EGF in burn wound healing and suggest that the response to injury includes deposition of HB-EGF and PDGF into blister fluid and a redistribution of HB-EGF in the surface epithelium near the wound site

    Novel cyclic di-GMP effectors of the YajQ protein family control bacterial virulence

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    Bis-(3 ',5 ') cyclic di-guanylate (cyclic di-GMP) is a key bacterial second messenger that is implicated in the regulation of many critical processes that include motility, biofilm formation and virulence. Cyclic di-GMP influences diverse functions through interaction with a range of effectors. Our knowledge of these effectors and their different regulatory actions is far from complete, however. Here we have used an affinity pull-down assay using cyclic di-GMP-coupled magnetic beads to identify cyclic di-GMP binding proteins in the plant pathogen Xanthomonas campestris pv. campestris (Xcc). This analysis identified XC_3703, a protein of the YajQ family, as a potential cyclic di-GMP receptor. Isothermal titration calorimetry showed that the purified XC_3703 protein bound cyclic di-GMP with a high affinity (K-d similar to 2 mu M). Mutation of XC_3703 led to reduced virulence of Xcc to plants and alteration in biofilm formation. Yeast two-hybrid and far-western analyses showed that XC_3703 was able to interact with XC_2801, a transcription factor of the LysR family. Mutation of XC_2801 and XC_3703 had partially overlapping effects on the transcriptome of Xcc, and both affected virulence. Electromobility shift assays showed that XC_3703 positively affected the binding of XC_2801 to the promoters of target virulence genes, an effect that was reversed by cyclic di-GMP. Genetic and functional analysis of YajQ family members from the human pathogens Pseudomonas aeruginosa and Stenotrophomonas maltophilia showed that they also specifically bound cyclic di-GMP and contributed to virulence in model systems. The findings thus identify a new class of cyclic di-GMP effector that regulates bacterial virulence

    ArborZ: Photometric Redshifts Using Boosted Decision Trees

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    Precision photometric redshifts will be essential for extracting cosmological parameters from the next generation of wide-area imaging surveys. In this paper we introduce a photometric redshift algorithm, ArborZ, based on the machine-learning technique of Boosted Decision Trees. We study the algorithm using galaxies from the Sloan Digital Sky Survey and from mock catalogs intended to simulate both the SDSS and the upcoming Dark Energy Survey. We show that it improves upon the performance of existing algorithms. Moreover, the method naturally leads to the reconstruction of a full probability density function (PDF) for the photometric redshift of each galaxy, not merely a single "best estimate" and error, and also provides a photo-z quality figure-of-merit for each galaxy that can be used to reject outliers. We show that the stacked PDFs yield a more accurate reconstruction of the redshift distribution N(z). We discuss limitations of the current algorithm and ideas for future work.Comment: 10 pages, 13 figures, submitted to Ap
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