245 research outputs found

    Evidence of Spatial Stability in Core Fauna Community Structure of Holopelagic Sargassum

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    As Sargassum biomass continues to increase globally, it is critical to develop a better understanding of how it functions as habitat, therefore, community structure of Sargassum-associated organisms was examined from 11 sampling locations spanning the tropical Florida Straits to the more temperate Gulf Stream off the coast of Savannah, Georgia from May to September 2018 using a combination of modified shrimp trawls and dip nets. A total of 5413 organisms were collected from Sargassum habitat representing 14 species from 10 families. A core group of organisms (Platynereis dumerilii, Litiopa melanostoma, Portunus sayi, Portunus spinimanus, Leander tenuicornis, and Latreutes fucorum) were found throughout the entirety of the geographic range surveyed. This core community did not vary significantly with increasing distance to shore or latitude, nor did it correlate with environmental variables such as salinity and temperature. However, community structure did vary with clump size, with larger clumps harboring more speciose communities. The Sargassum community in the Florida Straits and Gulf Stream appear to provide habitat for a consistent group of epifaunal organisms. In turn, this stable group offers a consistent prey source for a variety of important, higher trophic level organisms

    Development of Revised Energy Standards for Texas Buildings: Preliminary Results

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    In 1977, the State of Texas published a two-part Energy Conservation Manual to aid designers, builders, and contractors in the design of energy-efficient state buildings. Under the sponsorship of the Governor's Energy Management Center, the Center for Energy Studies (CES) at The University of Texas at Austin is revising and updating the nonresidential building portion of the Energy Conservation Manual. The proposed revision is a Texas-specific adaptation of ASHRAE Standard 90.1P ("Energy Efficient Design of New Buildings Except Low-Rise Residential Buildings"). These modifications include editorial changes, such as deletion of criteria that do not apply to Texas climates, as well as improved envelope criteria and the addition of HVAC system performance criteria. This paper documents the approach taken in the development of the revised Texas standards. Preliminary results are presented for the new envelope calculation procedures that will be included in the compliance software. This software will parallel that provided for the envelope and lighting sections in the ASHRAE Standard and will ultimately extend the standard to include a performance-based approach for HVAC systems and whole-building Energy Targets

    Energy Savings Resulting from Shading Devices on Single-Family Residences in Austin, Texas

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    Potential annual energy savings resulting from window shading devices on three prototypical Austin, Texas, single-family residences were computed in this study. Savings were calculated for interior (shades, blinds, draperies, window film, and tinted windows) and exterior (solar screens, awnings, overhangs, and the effects of recessed windows and vegetation) shading devices. The analysis was conducted with the DOE-2 building energy analysis computer program. Nominal baseline cases (single glazing, gas heating, and nominal shading from eaves and neighboring buildings) were run for each prototype. Selected baseline variants (double glazing, all electric, and no eaves or neighbor shading) were run to test parameter sensitivity. Results are reported in terms of the annual heating and cooling energy use and energy cost, with each device in place, as compared to the baseline cases. The devices are ranked in term of energy savings and energy coat savings. Another significant result is the multiple-regression correlation of annual heating and cooling energy savings with Shading Coefficient and U-value that generalizes the performance of the shading devices

    Development of HVAC System Performance Criteria Using Factorial Design and DOE-2 Simulation

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    A new approach is described for the development of Heating, Ventilating, and Air-conditioning (HVAC) System Performance Criteria for the Texas Building Energy Design Standard. This approach integrates a design of experimental methodology and DOE-2 simulation to identify the effects of control parameters on HVAC system energy performance. Three new criteria - transport, plant, and system performance factors-are used as measures of system performance. The procedure has been applied to the development of criteria for a variable-air-volume (VAV) and a constant-air-volume (CAV) system in three Texas climates. The results show that the air distribution system pressure loss, cooling coil exit temperature set-pint, operation of an economizer, and use of dead band controls have significant effects on air transport energy use and total system performance. The selection of control strategies and set-points have a clear impact on energy use. There is also a great energy-saving potential of converting from a CAV to a VAV system

    An Expert System for Determining Compliance with the Texas Building Energy Design Standard

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    Demonstration of compliance with the Texas Building Energy Conservation Design Standard involves completion of a summary checklist for each of its sections. This manual checking is tedious. Furthermore, no comprehensive documentation of the user's compliance is provided and the compliance checker must manage the data collected. To assist designers in complying with the Standard and to reduce the time required, the Center for Energy Studies (CES) at the University of Texas at Austin has developed an expert system to serve as both the compliance procedure and its documentation. This expert system directs the user with queries (screen menus), prompting the user for all relevant information. A graphical user interface has been developed to facilitate quick navigation through the Standard, easy data entry, and identification of compliance failures. This paper describes the research approach to the expert system, the system features, current status of project, and the benefits to be derived from this innovative compliance tool

    Modeling resilience and sustainability in ancient agricultural systems

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    The reasons why people adopt unsustainable agricultural practices, and the ultimate environmental implications of those practices, remain incompletely understood in the present world. Archaeology, however, offers unique datasets on coincident cultural and ecological change, and their social and environmental effects. This article applies concepts derived from ecological resilience thinking to assess the sustainability of agricultural practices as a result of long-term interactions between political, economic, and environmental systems. Using the urban center of Gordion, in central Turkey, as a case study, it is possible to identify mismatched social and ecological processes on temporal, spatial, and organizational scales, which help to resolve thresholds of resilience. Results of this analysis implicate temporal and spatial mismatches as a cause for local environmental degradation, and increasing extralocal economic pressures as an ultimate cause for the adoption of unsustainable land-use practices. This analysis suggests that a research approach that integrates environmental archaeology with a resilience perspective has considerable potential for explicating regional patterns of agricultural change and environmental degradation in the past

    Loss of the interferon-γ-inducible regulatory immunity-related GTPase (IRG), Irgm1, causes activation of effector IRG proteins on lysosomes, damaging lysosomal function and predicting the dramatic susceptibility of Irgm1-deficient mice to infection

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    The interferon-γ (IFN-γ)-inducible immunity-related GTPase (IRG), Irgm1, plays an essential role in restraining activation of the IRG pathogen resistance system. However, the loss of Irgm1 in mice also causes a dramatic but unexplained susceptibility phenotype upon infection with a variety of pathogens, including many not normally controlled by the IRG system. This phenotype is associated with lymphopenia, hemopoietic collapse, and death of the mouse.Deutscher Akademischer Austausch Dienst (DAAD); International Graduate School in Development Health and Disease (IGS-DHD); Deutsche For-schungsgemeinschaft (SFBs 635, 670, 680); Max-Planck-Gesellschaft (Max Planck Fellowship)
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