3,757 research outputs found
SPATIAL ECOLOGY AND HABITAT USE OF THE WESTERN MASSASAUGA (SISTRURUS TERGEMINUS) IN NEBRASKA
We used radiotelemetry during 2004 and 2005 to investigate seasonal movements and habitat use and to improve our understanding of how land management practices were affecting Western Massasauga (Sistrurus tergeminus) populations in Nebraska. We found Western Massasaugas to brumate in crayfish burrows 100% of the time, and spring emergence occurred during March - April. The longest movements occurred during May when snakes were moving away from brumation sites to summer habitat, after which movements decreased until a second peak in August. We did not find significant differences between male and female activity area, range length, total distance moved, daily movement, or distance from spring and fall brumation sites. However the core activity range of females was significantly less than that of males. During the active season, grassland habitat was used 75.6% of the time compared to habitats of grassland-shrubs (10.7%), hydrophilic vegetation (9.1%), woodlands (3.1%), and shrublands (1.5%). Identifying variations in a species spatial ecology is important for achieving long-term conservation goals because life history events, resource availability, and land management practices may have an effect on seasonal movements and habitat use. The results of our study demonstrate the need for, and some of the necessary data for, improved land management planning in order to meet conservation needs of the Western Massasauga in Nebraska
Some Financial Measures For The Busy Small Business Owner
Small business owners have a number of things that demand their attention. Yet, virtually all of them are concerned with how their business is doing. Many suggestions have been made in an effort to address that concern. In this paper, a straight-forward approach is suggested, which is not overly complicated yet not overly simplistic either. With the use of five financial measurements, the busy small business owner can gain a keen appreciation of how the business is doing. The measures serve as indicators of various aspects of the business and, at the same time, present a solid overall picture. Further action is then dependent on the time, inclination, and resources of the owner
Odonata species of special concern for Oklahoma, USA
Assessment of conservation status is a necessary step before management plans can be formulated. Historically such assessments have a strong bias toward vertebrates, particularly endothermic terrestrial vertebrates (i.e. birds and mammals). Invertebrates, by contrast, tend to be ignored, and many insect groups, despite being species rich and reasonably well studied, such as the Odonata (damselflies and dragonflies), have not been assessed or have been assessed only at a broad geographic level (e.g. internationally or continentally). Assessment at a state level recognizes that states often are at the front of regional and local conservation and management planning and implementation. On the basis of our extensive surveys across the Great Plains state of Oklahoma in the central USA, as well as our compilation of thousands of museum specimens dating back to 1877, we were able to discern the status and distribution of each of the 161 species of odonates recorded in the state. In doing so we were able to assess a conservation rank, using NatureServe criteria, for each species.We conclude that nine species are critically imperiled (S1) in the state. These species require immediate conservation attention, initially at the level of intensive surveys to delineate the full extent of the geographic range in the state and to determine the population size and habitat needs. We categorized an additional 13 species as imperiled (S2) and placed 18 species on a “watch list” (S3). Species on these two lists will require field surveys as well, and regions of high occurrence of listed species ought to be targeted for such efforts and considered as set-asides for preservation of key members of the odonate fauna in the state
Jakatar- Proposing a New Lifestyle
There are two major effects of global warming; rising temperatures and melting glaciers. More than five million cubic miles of ice fields are continuously melting. Experts estimate if all melting drains to the sea, the sea-level would rise 216 feet. It will cause a different life style for the future. The effects of sea-level rise are scarcity of resources and a lack of habitat. We propose a new infrastructure, through the use of existing buildings, with different function to help humanity cope with rising sea-levels
Filler bar heating due to stepped tiles in the shuttle orbiter thermal protection system
An analytical study was performed to investigate the excessive heating in the tile to tile gaps of the Shuttle Orbiter Thermal Protection System due to stepped tiles. The excessive heating was evidence by visible discoloration and charring of the filler bar and strain isolation pad that is used in the attachment of tiles to the aluminum substrate. Two tile locations on the Shuttle orbiter were considered, one on the lower surface of the fuselage and one on the lower surface of the wing. The gap heating analysis involved the calculation of external and internal gas pressures and temperatures, internal mass flow rates, and the transient thermal response of the thermal protection system. The results of the analysis are presented for the fuselage and wing location for several step heights. The results of a study to determine the effectiveness of a half height ceramic fiber gap filler in preventing hot gas flow in the tile gaps are also presented
Functional Integration of Ecological Networks through Pathway Proliferation
Large-scale structural patterns commonly occur in network models of complex
systems including a skewed node degree distribution and small-world topology.
These patterns suggest common organizational constraints and similar functional
consequences. Here, we investigate a structural pattern termed pathway
proliferation. Previous research enumerating pathways that link species
determined that as pathway length increases, the number of pathways tends to
increase without bound. We hypothesize that this pathway proliferation
influences the flow of energy, matter, and information in ecosystems. In this
paper, we clarify the pathway proliferation concept, introduce a measure of the
node--node proliferation rate, describe factors influencing the rate, and
characterize it in 17 large empirical food-webs. During this investigation, we
uncovered a modular organization within these systems. Over half of the
food-webs were composed of one or more subgroups that were strongly connected
internally, but weakly connected to the rest of the system. Further, these
modules had distinct proliferation rates. We conclude that pathway
proliferation in ecological networks reveals subgroups of species that will be
functionally integrated through cyclic indirect effects.Comment: 29 pages, 2 figures, 3 tables, Submitted to Journal of Theoretical
Biolog
Creating Legitimacy for Sustainability Assurance Practices: Evidence from Sustainability Restatements
This is the author accepted manuscript. The final version is available from Taylor & Francis (Routledge) via the DOI in this record.This study examines sustainability reporting assurance (SRA) provider use of sustainability
restatements as a means to create legitimacy in the developing SRA market. In comparison to
financial data, mistakes in sustainability reporting are more likely to be made and less likely
to be discovered prior to reporting. A lack of clear reporting standards and ambiguous SRA
guidelines create a setting where providers can use restatements in an attempt to demonstrate
both a problem in sustainability reporting and assurance as the solution to that issue. Based
on a sample of U.S. firms from 2010–14, we find that SRA is associated with an increased
likelihood of sustainability restatements, that the association is stronger for error restatements
than for restatements due to methodological updates, and that SRA is significantly associated
with the disclosure of quantitatively non-material restatements. We also document
differences in these relations across provider-type, with only consultant assurance
significantly associated with methodological restatements and restatements of a non-material
amount. Our findings support differences between sustainability report restatements and
financial restatements, and provide evidence in support of our argument that assurance
providers may be using restatements in an attempt to expand market share in a new
professional space.We also gratefully acknowledge the 2014
Best Paper Prize awarded by the PRI Stichting Foundation at the 2nd GARI International
Conference (Henley Business School) and financial support from the University of Exeter
Firms, Markets and Value Research Cluster and the School of Accounting, Rawls College of
Business at Texas Tech University
L and T Dwarf Models and the L to T Transition
Using a model for refractory clouds, a novel algorithm for handling them, and
the latest gas-phase molecular opacities, we have produced a new series of L
and T dwarf spectral and atmosphere models as a function of gravity and
metallicity, spanning the \teff range from 2200 K to 700 K. The correspondence
with observed spectra and infrared colors for early- and mid-L dwarfs and for
mid- to late-T dwarfs is good. We find that the width in infrared
color-magnitude diagrams of both the T and L dwarf branches is naturally
explained by reasonable variations in gravity and, therefore, that gravity is
the "second parameter" of the L/T dwarf sequence. We investigate the dependence
of theoretical dwarf spectra and color-magnitude diagrams upon various cloud
properties, such as particle size and cloud spatial distribution. In the region
of the LT transition, we find that no one cloud-particle-size and gravity
combination can be made to fit all the observed data. Furthermore, we note that
the new, lower solar oxygen abundances of Allende-Prieto, Lambert, & Asplund
(2002) produce better fits to brown dwarf data than do the older values.
Finally, we discuss various issues in cloud physics and modeling and speculate
on how a better correspondence between theory and observation in the
problematic LT transition region might be achieved.Comment: accepted to the Astrophysical Journal, 21 figures (20 in color);
spectral models in electronic form available at
http://zenith.as.arizona.edu/~burrow
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