41 research outputs found

    Baffin Island Fjord Macrobenthos: Bottom Communities and Environmental Significance

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    Cluster analysis of the benthos from ten Baffin Island fjords defines six faunal associations. The macrotidal Sunneshine Fiord has a shallow kelp-related Isopod Association. Cambridge Fiord supports a shallow Onuphid Association controlled by gravel from dropstones. A widespread Portlandia Association typified the shallow zones of more recently glaciated fjords where sedimentation rates are high. An Ophiuroid-Anemone Association was defined from current-affected submarine channel environments. A Maldanid Association covered the greatest area in all fjords and passed into an Elasipod Association in the deepest water in Cambridge Fiord. Fjord-head faunas are used to model ecological changes accompanying glacier retreat, from monospecific Portlandia, through mature Portlandia Association to Onuphid Association accompanied by diverse filter feeders and herbivores. Chlamys islandica was found living in Cambridge Fiord, which substantially increases its northern limit.Key words: macrobenthos, Arctic, cluster analysis, bivalve, Quaternary, sedimentMots clés: macrobenthos, Arctique, analyse d’ensemble, bivalve, quaternaire, sédiment

    Search for Gravitational Waves Associated with Gamma-Ray Bursts Detected by Fermi and Swift during the LIGO-Virgo Run O3b

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    We search for gravitational-wave signals associated with gamma-ray bursts (GRBs) detected by the Fermi and Swift satellites during the second half of the third observing run of Advanced LIGO and Advanced Virgo (2019 November 1 15:00 UTC-2020 March 27 17:00 UTC). We conduct two independent searches: A generic gravitational-wave transients search to analyze 86 GRBs and an analysis to target binary mergers with at least one neutron star as short GRB progenitors for 17 events. We find no significant evidence for gravitational-wave signals associated with any of these GRBs. A weighted binomial test of the combined results finds no evidence for subthreshold gravitational-wave signals associated with this GRB ensemble either. We use several source types and signal morphologies during the searches, resulting in lower bounds on the estimated distance to each GRB. Finally, we constrain the population of low-luminosity short GRBs using results from the first to the third observing runs of Advanced LIGO and Advanced Virgo. The resulting population is in accordance with the local binary neutron star merger rate. © 2022. The Author(s). Published by the American Astronomical Society

    Narrowband Searches for Continuous and Long-duration Transient Gravitational Waves from Known Pulsars in the LIGO-Virgo Third Observing Run

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    Isolated neutron stars that are asymmetric with respect to their spin axis are possible sources of detectable continuous gravitational waves. This paper presents a fully coherent search for such signals from eighteen pulsars in data from LIGO and Virgo's third observing run (O3). For known pulsars, efficient and sensitive matched-filter searches can be carried out if one assumes the gravitational radiation is phase-locked to the electromagnetic emission. In the search presented here, we relax this assumption and allow both the frequency and the time derivative of the frequency of the gravitational waves to vary in a small range around those inferred from electromagnetic observations. We find no evidence for continuous gravitational waves, and set upper limits on the strain amplitude for each target. These limits are more constraining for seven of the targets than the spin-down limit defined by ascribing all rotational energy loss to gravitational radiation. In an additional search, we look in O3 data for long-duration (hours-months) transient gravitational waves in the aftermath of pulsar glitches for six targets with a total of nine glitches. We report two marginal outliers from this search, but find no clear evidence for such emission either. The resulting duration-dependent strain upper limits do not surpass indirect energy constraints for any of these targets. © 2022. The Author(s). Published by the American Astronomical Society

    International Multicenter Experience of Isolated Limb Infusion for In-Transit Melanoma Metastases in Octogenarian and Nonagenarian Patients

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    BACKGROUND:Isolated limb infusion (ILI) is used to treat in-transit melanoma metastases confined to an extremity. However, little is known about its safety and efficacy in octogenarians and nonagenarians (ON). PATIENTS AND METHODS:ON patients (≥ 80 years) who underwent a first ILI for American Joint Committee on Cancer seventh edition stage IIIB/IIIC melanoma between 1992 and 2018 at nine international centers were included and compared with younger patients (< 80 years). A cytotoxic drug combination of melphalan and actinomycin-D was used. RESULTS:Of the 687 patients undergoing a first ILI, 160 were ON patients (median age 84 years; range 80-100 years). Compared with the younger cohort (n = 527; median age 67 years; range 29-79 years), ON patients were more frequently female (70.0% vs. 56.9%; p = 0.003), had more stage IIIB disease (63.8 vs. 53.3%; p = 0.02), and underwent more upper limb ILIs (16.9% vs. 9.5%; p = 0.009). ON patients experienced similar Wieberdink limb toxicity grades III/IV (25.0% vs. 29.2%; p = 0.45). No toxicity-related limb amputations were performed. Overall response for ON patients was 67.3%, versus 64.6% for younger patients (p = 0.53). Median in-field progression-free survival was 9 months for both groups (p = 0.88). Median distant progression-free survival was 36 versus 23 months (p = 0.16), overall survival was 29 versus 40 months (p < 0.0001), and melanoma-specific survival was 46 versus 78 months (p = 0.0007) for ON patients compared with younger patients, respectively. CONCLUSIONS:ILI in ON patients is safe and effective with similar response and regional control rates compared with younger patients. However, overall and melanoma-specific survival are shorter.Jüri Teras, Hidde M. Kroon, John T. Miura, Tim Kenyon-Smith, Georgia M. Beasley, Dean Mullen, Norma E. Farrow, Paul J. Mosca, Michael C. Lowe, Clara R. Farley, Aishwarya Potdar, Hala Daou, James Sun, Michael Carr, Jeffrey M. Farma, Michael A. Henderson, David Speakman, Jonathan Serpell, Keith A. Delman, B. Mark Smithers, Andrew Barbour, Douglas S. Tyler, Brendon J. Coventry, Jonathan S. Zager, and John F. Thompso

    Automated selective caching for reference attribute grammars

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    Reference attribute grammars (RAGs) can be used to express semantics as super-imposed graphs on top of abstract syntax trees (ASTs). A RAG-based AST can be used as the in-memory model providing semantic information for software language tools such as compilers, refactoring tools, and meta- modeling tools. RAG performance is based on dynamic attribute evaluation with caching. Caching all attributes gives optimal performance in the sense that each attribute is evaluated at most once. However, performance can be further improved by a selective caching strategy, avoiding caching overhead where it does not pay off. In this paper we present a profiling-based technique for automatically finding a good caching configuration. The technique has been evaluated on a generated Java compiler, compiling programs from the Jacks test suite and the DaCapo benchmark suite
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