93 research outputs found

    City of Gloucester Harbor Plan & Designated Port Area Master Plan, July 2009

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    A harbor plan is a waterfront land and water use plan intended to establish the community’s objectives, standards, and policies for guiding public and private utilization of land and of water within and adjacent to the commonwealth’s jurisdiction. The 1999 Gloucester Harbor Plan was chiefly focused on infrastructure improvements for both maritime and visitor oriented industries along the waterfront as a central means of recharging the harbor’s economic engine. Many of the improvements have been completed in the wake of this plan. However, it largely ignored the confusing web of land use regulations that has since emerged as the central force stagnating much of the waterfront’s revitalization. Gloucester Harbor is the center of one of the country’s most important commercial fishing communities; its docks lined with vessels of various types and its waterfront dominated by facilities and services associated with seafood industry. In recent decades, as the groundfish stocks have declined and management measures designed to rebuild the stocks have reduced the size and effort of the fleet, the infrastructure has deteriorated and businesses that depend on groundfish have struggled

    NIHAO IV: Core creation and destruction in dark matter density profiles across cosmic time

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    We use the NIHAO simulations to investigate the effects of baryonic physics on the time evolution of Dark Matter central density profiles. The sample is made of 70\approx 70 independent high resolution hydrodynamical simulations of galaxy formation and covers a wide mass range: 1e10< Mhalo <1e12, i.e., from dwarfs to L* . We confirm previous results on the dependence of the inner dark matter density slope, α\alpha, on the ratio between stellar-to-halo mass. We show that this relation holds approximately at all redshifts (with an intrinsic scatter of ~0.18 in α\alpha). This implies that in practically all haloes the shape of their inner density profile changes quite substantially over cosmic time, as they grow in stellar and total mass. Thus, depending on their final stellar-to-halo mass ratio, haloes can either form and keep a substantial density core (size~1 kpc), or form and then destroy the core and re-contract the halo, going back to a cuspy profile, which is even steeper than CDM predictions for massive galaxies (~1e12 Msun). We show that results from the NIHAO suite are in good agreement with recent observational measurements of α\alpha in dwarf galaxies. Overall our results suggest that the notion of a universal density profile for dark matter haloes is no longer valid in the presence of galaxy formation.Comment: 11 pages, 13 figures. Corrected typo in table 2 (middle row) with respect to the version published in MNRA

    Limitations of variable number of tandem repeat typing identified through whole genome sequencing of Mycobacterium avium subsp. paratuberculosis on a national and herd level

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    Background: Mycobacterium avium subsp. paratuberculosis (MAP), the causative bacterium of Johne’s disease in dairy cattle, is widespread in the Canadian dairy industry and has significant economic and animal welfare implications. An understanding of the population dynamics of MAP can be used to identify introduction events, improve control efforts and target transmission pathways, although this requires an adequate understanding of MAP diversity and distribution between herds and across the country. Whole genome sequencing (WGS) offers a detailed assessment of the SNP-level diversity and genetic relationship of isolates, whereas several molecular typing techniques used to investigate the molecular epidemiology of MAP, such as variable number of tandem repeat (VNTR) typing, target relatively unstable repetitive elements in the genome that may be too unpredictable to draw accurate conclusions. The objective of this study was to evaluate the diversity of bovine MAP isolates in Canadian dairy herds using WGS and then determine if VNTR typing can distinguish truly related and unrelated isolates.&lt;p&gt;&lt;/p&gt; Results: Phylogenetic analysis based on 3,039 SNPs identified through WGS of 124 MAP isolates identified eight genetically distinct subtypes in dairy herds from seven Canadian provinces, with the dominant type including over 80% of MAP isolates. VNTR typing of 527 MAP isolates identified 12 types, including “bison type” isolates, from seven different herds. At a national level, MAP isolates differed from each other by 1–2 to 239–240 SNPs, regardless of whether they belonged to the same or different VNTR types. A herd-level analysis of MAP isolates demonstrated that VNTR typing may both over-estimate and under-estimate the relatedness of MAP isolates found within a single herd.&lt;p&gt;&lt;/p&gt; Conclusions: The presence of multiple MAP subtypes in Canada suggests multiple introductions into the country including what has now become one dominant type, an important finding for Johne’s disease control. VNTR typing often failed to identify closely and distantly related isolates, limiting the applicability of using this typing scheme to study the molecular epidemiology of MAP at a national and herd-level.&lt;p&gt;&lt;/p&gt

    Aerothermodynamic Analyses of Towed Ballutes

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    A ballute (balloon-parachute) is an inflatable, aerodynamic drag device for application to planetary entry vehicles. Two challenging aspects of aerothermal simulation of towed ballutes are considered. The first challenge, simulation of a complete system including inflatable tethers and a trailing toroidal ballute, is addressed using the unstructured-grid, Navier-Stokes solver FUN3D. Auxiliary simulations of a semi-infinite cylinder using the rarefied flow, Direct Simulation Monte Carlo solver, DSV2, provide additional insight into limiting behavior of the aerothermal environment around tethers directly exposed to the free stream. Simulations reveal pressures higher than stagnation and corresponding large heating rates on the tether as it emerges from the spacecraft base flow and passes through the spacecraft bow shock. The footprint of the tether shock on the toroidal ballute is also subject to heating amplification. Design options to accommodate or reduce these environments are discussed. The second challenge addresses time-accurate simulation to detect the onset of unsteady flow interactions as a function of geometry and Reynolds number. Video of unsteady interactions measured in the Langley Aerothermodynamic Laboratory 20-Inch Mach 6 Air Tunnel and CFD simulations using the structured grid, Navier-Stokes solver LAURA are compared for flow over a rigid spacecraft-sting-toroid system. The experimental data provides qualitative information on the amplitude and onset of unsteady motion which is captured in the numerical simulations. The presence of severe unsteady fluid - structure interactions is undesirable and numerical simulation must be able to predict the onset of such motion

    Determining the Quantitative Principles of T Cell Response to Antigenic Disparity in Stem Cell Transplantation

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    Alloreactivity compromising clinical outcomes in stem cell transplantation is observed despite HLA matching of donors and recipients. This has its origin in the variation between the exomes of the two, which provides the basis for minor histocompatibility antigens (mHA). The mHA presented on the HLA class I and II molecules and the ensuing T cell response to these antigens results in graft vs. host disease. In this paper, results of a whole exome sequencing study are presented, with resulting alloreactive polymorphic peptides and their HLA class I and HLA class II (DRB1) binding affinity quantified. Large libraries of potentially alloreactive recipient peptides binding both sets of molecules were identified, with HLA-DRB1 generally presenting a greater number of peptides. These results are used to develop a quantitative framework to understand the immunobiology of transplantation. A tensor-based approach is used to derive the equations needed to determine the alloreactive donor T cell response from the mHA-HLA binding affinity and protein expression data. This approach may be used in future studies to simulate the magnitude of expected donor T cell response and determine the risk for alloreactive complications in HLA matched or mismatched hematopoietic cell and solid organ transplantation

    A Proposed Role of Aeroelasticity in NASA's New Exploration Vision

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    On 14 January 2004, NASA received a mandate to return astronauts to the Moon, evolve a sustained presence there, then head out into the solar system to Mars and perhaps beyond. This new space exploration initiative directs NASA to develop human and robotic technologies that can deliver payloads larger than Apollo to the Moon, to Mars, and bring astronauts and samples safely back to Earth at costs much lower than Apollo. These challenges require creative aerospace systems. On proposed technology for safely delivering payloads to the surface of Mars and returning samples to Earth involves deployed flexible and inflatable decelerators for atmospheric entry. Because inflatable decelerators provide the entry vehicle more drag surface area at smaller mass than traditional ablative devices, this class of decelerators can potentially accomodate larger mass payloads. The flexibility of these lightweight aeroshells can pose both vehicle and aeroelastic stability problems if not properly designed for the expected flight regimes. Computational tools need to be developed for modelling the large and nonlinear deformations of these highly flexible structures. Unlike wind tunnel testing, an integrated and efficient aeroelastic analysis tool can explore the entire flight environment. This paper will provide some background on flexible deployable decelerators, survey the current state of technology and outline the proposed development of an aeroelastic analysis and capability

    Submersible study of an oceanic megamullion in the central North Atlantic

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    Author Posting. © American Geophysical Union, 2001. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 106, no. B8 (2001): 16145–16161, doi:10.1029/2001JB000373.Recently discovered megamullions on the seafloor have been interpreted to be the exhumed footwalls of long-lived detachment faults operating near the ends of spreading segments in slow spreading crust. We conducted five submersible dives on one of these features just east of the rift valley in the Mid-Atlantic Ridge at 26°35′N and obtained visual, rock sample, gravity, and heat flow data along a transect from the breakaway zone (where the fault is interpreted to have first nucleated in ∼2.0–2.2 Ma crust) westward to near the termination (∼0.7 Ma). Our observations are consistent with the detachment fault hypothesis and show the following features. In the breakaway zone, faulted and steeply backtilted basaltic blocks suggest rotation above a deeper shear zone; the youngest normal faults in this sequence are interpreted to have evolved into the long-lived detachment fault. In younger crust the interpreted detachment surface rises as monotonously flat seafloor in a pair of broad, gently sloping domes that formed simultaneously along isochrons and are now thinly covered by sediment. The detachment surface is locally littered with basaltic debris that may have been clipped from the hanging wall. The domes coincide with a gravity high that continues along isochrons within the spreading segment. Modeling of on-bottom gravity measurements and recovery of serpentinites imply that mantle rises steeply and is exposed within ∼7 km west of the breakaway but that rocks with intermediate densities prevail farther west. Within ∼5 km of the termination, small volcanic cones appear on the detachment surface, indicating melt input into the footwall. We interpret the megamullion to have developed during a phase of limited magmatism in the spreading segment, with mantle being exhumed by the detachment fault <0.5 m.y. after its initiation. Increasing magmatism may eventually have weakened the lithosphere and facilitated propagation of a rift that terminated slip on the detachment fault progressively between ∼1.3 m.y. and 0.7 m.y. Identifiable but low-amplitude magnetic anomalies over the megamullion indicate that it incorporates a magmatic component. We infer that much of the footwall is composed of variably serpentinized peridotite intruded by plutons and dikes.B. Tucholke's research was supported by NSF grant OCE-9503561 and by an award from the Andrew W. Mellon Foundation Endowed Fund for Innovative Research and the Henry Bryant Bigelow Chair in Oceanography at Woods Hole Oceanographic Institution. G. Hirth acknowledges support by NSF grant OCE-9907244

    Crop updates 2006 - Farming Systems

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    This session covers nineteen papers from different authors: SOIL AND NUTRIENT MANAGEMENT 1. Invetigatingfertilitigating fertilier inve$tment, Wayne Pluske, Nutrient Management Systems 2. KASM, the potassium in Agricultural System Model,Bill Bowden and Craig Scanlan, DAWA Northam and UWA, School of Earth and Geographical Sciences 3. Long term productivity and economic benefits of subsurface acidity management from surface and subsurface liming, Stephen Davies, Chris Gazey and Peter Tozer, Department of Agriculture 4. Furrow and ridges to prevent waterlogging, Dr Derk Bakker, Department of Agriculture 5. Nitrous oxide emissions from a cropped soil in Western Australia, Louise Barton1, David Gatter2, Renee Buck1, Daniel Murphy1, Christoph Hinz1and Bill Porter2 1School of Earth and Geographical Sciences, The University of Western Australia, 2Department of Agriculture GROWER DECISIONS 6. Managing the unmanageable, Bill Bowden Department of Agriculture 7. Review of climate model summaries reported in Department of Agriculture’s Season Outlook, Meredith Fairbanks, Department of Agriculture 8. Mapping the frost risk in Western Australia, Nicolyn Short and Ian Foster, Department of Agriculture 9. .35 kg/ha.day and other myths, James Fisher, Doug Abrecht and Mario D’Antuono, Department of Agriculture 10. Gaining with growers – Lessons from a successful alliance of WA Grower Groups, Tracey M. Gianatti, Grower Group Alliance 11. WA Agribusiness Trial Network Roundup – 2005, Paul Carmody, Local Farmer Group Network, UWA 12. Drivers of no-till adoption, Frank D’Emdenabc, Rick Llewellynabdand Michael Burtonb,aCRC Australian Weed Management; bSchool of Agricultural and Resource Economics, UWA. cDepartment of Agriculture, dCSIRO Sustainable Ecosystems, Adelaide PRODUCTION SYSTEMS, PRECISION AGRICULTURE AND SUSTAINABILITY 13. Maintaining wheat and lupin yields using phase pastures and shielded sprayers to manage increasing herbicide resistance, Caroline Peek, Nadine Eva, Chris Carter and Megan Abrahams, Department of Agriculture 14. Analaysis of a wheat-pasture rotation in the 330mm annual rainfall zone using the STEP model, Andrew Blake and Caroline Peek, Department of Agriculture 15. Response to winter drought by wheat on shallow soil with low seeding rate and wide row spacing, Paul Blackwell1, Sylvain Pottier2and Bill Bowden1 1 Department of Agriculture; 2Esitpa (France) 16. How much yield variation do you need to justify zoning inputs? Michael Robertson and Greg Lyle, CSIRO Floreat, Bill Bowden, Department of Agriculture; Lisa Brennan, CSIRO Brisbane 17. Automatic guidance and wheat row position: On-row versus between-row seeding at various rates of banded P fertilisers, Tony J. Vyn1, Simon Teakle2, Peter Norris3and Paul Blackwell4,1Purdue University, USA; 2Landmark; 3Agronomy for Profit; 4 Department of Agriculture 18. Assessing the sustainability of high production systems (Avon Agricultural Systems Project), Jeff Russell and James Fisher, Department of Agriculture, Roy Murray-Prior and Deb Pritchard, Muresk Institute; Mike Collins, ex WANTFA, 19. The application of precision agriculture techniques to assess the effectiveness of raised beds on saline land in WA, Derk Bakker, Greg Hamilton, Rob Hetherington, Andrew Van Burgel and Cliff Spann, Department of Agricultur

    Mantle dynamics beneath the East Pacific Rise at 17°S : insights from the Mantle Electromagnetic and Tomography (MELT) experiment

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    Author Posting. © American Geophysical Union, 2006. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 111 (2006): B02101, doi:10.1029/2004JB003598.The electromagnetic data from the Mantle Electromagnetic and Tomography (MELT) experiment are inverted for a two-dimensional transversely anisotropic conductivity structure that incorporates a correction for three-dimensional topographic effects on the magnetotelluric responses. The model space allows for different conductivity values in the along-strike, cross-strike, and vertical directions, along with imposed constraints of model smoothness and closeness among the three directions. Anisotropic models provide a slightly better fit to the data for a given level of model smoothness and are more consistent with other geophysical and laboratory data. The preferred anisotropic model displays a resistive uppermost 60-km-thick mantle independent of plate age, except in the vicinity of the ridge crest. In most inversions, a vertically aligned sheet-like conductor at the ridge crest is especially prominent in the vertical conductivity. Its presence suggests that the melt is more highly concentrated and connected in the vertical direction immediately beneath the rise axis. The melt zone is at least 100 km wide and is asymmetric, having a greater extent to the west. Off-axis, and to the east of the ridge, the mantle is more conductive in the direction of plate spreading at depths greater than 60 km. The flat resistive-conductive boundary at 60 km agrees well with the inferred depth of the dry solidus of peridotite, and the deeper conductive region is consistent with the preferred orientation of olivine inferred from seismic observations. This suggests that the uppermost 60 km represents the region of mantle that has undergone melting at the ridge and has been depleted of water (dissolved hydrogen). By contrast, the underlying mantle has retained a significant amount of water.This work was supported by NSF grant OCE0118254 and the Research Program on Mantle Core Dynamics, Institute for Research on Earth Evolution (IFREE), Japan Agency for Marine-Earth Science and Technology (JAMSTEC)
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