21,227 research outputs found

    Innovative approach in the stabilisation of coastal slopes

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    Coastal slope instability poses a risk to life and material properties and is of great concern in times of climate change, posing challenges as communities seek to adapt and ensure resilience. This paper presents two case studies of coastal slope stabilisation efforts from Scotland and reflects the growing difficultly faced by coastal communities who value intervention but are limited by uncertain ownership, funding and access to expertise. In both cases, the slopes are owned by private charities with no power of authorisation or means of procuring stabilisation works to protect the adjacent communities. The engineering solutions included an innovative eco-engineering component where vegetation was used to perform an engineering function. Based on the experience with these projects, the authors advocate this sustainable technique supported by the evidence from monitoring and testing. The case studies emphasise the importance of engaging with the community as a means of achieving acceptance of a workable solution as well as participation in its long-term development. Another significant observation was the contribution played by establishment of a learning culture that is supported through inter- and intraproject knowledge transfer deemed necessary to promote the necessary double-loop learning evident in these projects. </jats:p

    Chipping away at gamma-H2AX foci

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    The mammalian histone H2AX protein functions as a dosage-dependent genomic caretaker and tumor suppressor. Phosphorylation of H2AX to form gamma-H2AX in chromatin around DNA double strand breaks (DSBs) is an early event following induction of these hazardous lesions. For a decade, mechanisms that regulate H2AX phosphorylation have been investigated mainly through two-dimensional immunofluorescence (IF). We recently used chromatin immunoprecipitation (ChIP) to measure gamma-H2AX densities along chromosomal DNA strands broken in G(1) phase mouse lymphocytes. Our experiments revealed that (1) gamma-H2AX densities in nucleosomes form at high levels near DSBs and at diminishing levels farther and farther away from DNA ends, and (2) ATM regulates H2AX phosphorylation through both MDC1-dependent and MDC1-independent means. Neither of these mechanisms were discovered by previous if studies due to the inherent limitations of light microscopy. Here, we compare data obtained from parallel gamma-H2AX ChIP and three-dimensional IF analyses and discuss the impact of our findings upon molecular mechanisms that regulate H2AX phosphorylation in chromatin around DNA breakage sites

    Diverse hypolithic refuge communities in the McMurdo Dry Valleys

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    Hyper-arid deserts present extreme challenges to life. The environmental buffering provided by quartz and other translucent rocks allows hypolithic microbial communities to develop on sub-soil surfaces of such rocks. These refuge communities have been reported, for many locations worldwide, to be predominantly cyanobacterial in nature. Here we report the discovery in Antarctica’s hyper-arid McMurdo Dry Valleys of three clearly distinguishable types of hypolithic community. Based on gross colonization morphology and identification of dominant taxa, we have classified hypolithic communities as Type I (cyanobacterial dominated), Type II (fungal dominated) and Type III (moss dominated). This discovery supports a growing awareness of the high biocomplexity in Antarctic deserts, emphasizes the possible importance of cryptic microbial communities in nutrient cycling and provides evidence for possible successional community processes within a cold arid landscape

    Evidence of Songbird Intoxication From Rozol Application at a Black-Tailed Prairie Dog Colony

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    Concerns about avian poisonings from anticoagulant rodenticides have traditionally focused on secondary poisoning of raptors exposed by feeding on contaminated mammalian prey. However, ground foraging songbirds can be directly poisoned from operational applications of the anticoagulant rodenticide RozolH (0.005% chlorophacinone, active ingredient) applied as a grain bait, at black-tailed prairie dog Cynomys ludovicianus colonies. A dead western meadowlark Sturnella neglecta recovered from the study prairie dog colony displayed hemorrhaging in brain and pectoral muscle tissue, and it contained chlorophacinone residue concentrations of 0.59 and 0.49 mg/g (wet weight) in the liver and intestinal contents, respectively. Chlorophacinone residues from two Rozol-colored songbird droppings found at the study colony were 0.09 and 0.46 mg/g (wet weight). The timing of the meadowlark mortality and the occurrence of discolored droppings show that songbird exposure and poisoning can occur weeks after a Rozol application

    Modified sorting technique to mitigate the collateral mortality of trawled school prawns (Metapenaeus macleayi)

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    The potential for changes to onboard handling practices in order to improve the fate of juvenile school prawns (Metapenaeus macleayi) discarded during trawling were investigated in two Australian rivers (Clarence and Hunter) by comparing a purpose-built, water-filled sorting tray against a conventional dry tray across various conditions, including the range of typical delays before the start of sorting the catch (2 min vs. 15 min). Juvenile school prawns (n= 5760), caught during 32 and 16 deployments in each river, were caged and sacrificed at four times: immediately (T0), and at 24 (T24), 72 (T72), and 120 (T12 0) hours after having been discarded. In both rivers, most mortalities occurred between T0 and T24 and, after adjusting for control deaths (<12%), were greatest for the 15-min conventional treatment (up to 41% at T120). Mixed-effects logistic models revealed that in addition to the sampling time, method of sorting, and delay in sorting, the weight of the catch, salinity, and percentage cloud cover were significant predictors of mortality. Although trawling caused some mortalities and comparable stress (measured as L -lactate) in all school prawns, use of the water tray lessened the negative impacts of some of the above factors across both the 2-min and 15-min delays in sorting so that the overall discard mortality was reduced by more than a third. When used in conjunction with selective trawls, widespread application of the water tray should help to improve the sustainability of trawling for school prawns

    An Extraordinary Scattered Broad Emission Line in a Type 2 QSO

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    An infrared-selected, narrow-line QSO has been found to exhibit an extraordinarily broad Halpha emission line in polarized light. Both the extreme width (35,000 km/sec full-width at zero intensity) and 3,000 km/sec redshift of the line centroid with respect to the systemic velocity suggest emission in a deep gravitational potential. An extremely red polarized continuum and partial scattering of the narrow lines at a position angle common to the broad-line emission imply extensive obscuration, with few unimpeded lines of sight to the nucleus.Comment: 4 pages, 1 figure, to appear in the Astrophysical Journal Letter

    Glueball mass measurements from improved staggered fermion simulations

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    We present the first 2+1 flavour spectrum measurements of glueball states using high statistics simulations with improved staggered fermions. We find a spectrum consistent with quenched measurements of scalar, pseudoscalar andtensor glueball states. The measurements were made using 5000 configurations at a lattice spacing of 0.123 fm and pion mass of 280 MeV and 3000 configurations at 0.092 fm with a pion mass of 360 MeV. We see some evidence of coupling to 2 pion states. We compare our results with the experimental glueball candidate spectrum as well as quenched glueball estimates.Comment: 22 pages, 19 figures and 8 tables, minor additions on mixing post-refere
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