245 research outputs found
Evidence of Spatial Stability in Core Fauna Community Structure of Holopelagic Sargassum
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
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
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
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
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
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
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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