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Full-Text Articles in Physical Sciences and Mathematics

Macroscopic Consequences Of Calcium Signaling In Microdomains: A First-Passage-Time Approach, Robert Rovetti Nov 2007

Macroscopic Consequences Of Calcium Signaling In Microdomains: A First-Passage-Time Approach, Robert Rovetti

Mathematics, Statistics and Data Science Faculty Works

Calcium (Ca) plays an important role in regulating various cellular processes. In a variety of cell types, Ca signaling occurs within microdomains where channels deliver localized pulses of Ca activating a nearby collection of Ca-sensitive receptors. The small number of channels involved ensures that the signaling process is stochastic. The aggregate response of several thousand of these microdomains yields a whole-cell response which dictates the cell behavior. Here, we study the statistical properties of a population of these microdomains in response to a trigger signal. We use a first-passage-time approach to show analytically how Ca release in the whole cell …


Scaling Behavior Of The Exchange-Bias Training Effect, Christian Binek, Srinivas Polisetty, Sarbeswar Sahoo Aug 2007

Scaling Behavior Of The Exchange-Bias Training Effect, Christian Binek, Srinivas Polisetty, Sarbeswar Sahoo

Christian Binek Publications

The dependence of the exchange-bias training effect on temperature and ferromagnetic film thickness is studied in detail and scaling behavior of the data is presented. Thickness-dependent exchange bias and its training are measured using the magneto-optical Kerr effect. A focused laser beam is scanned across a Co wedge probing local hysteresis loops of the Co film which is pinned by an antiferromagnetic CoO layer of uniform thickness. A phenomenological theory is best fitted to the exchange-bias training data resembling the evolution of the exchange-bias field on subsequently cycled hysteresis loops. Best fits are done for various temperatures and Co thicknesses. …


Multiple-Species Exclusion Fencing And Technology For Mainland Sites, Tim Day, Roger Macgibbon Aug 2007

Multiple-Species Exclusion Fencing And Technology For Mainland Sites, Tim Day, Roger Macgibbon

Managing Vertebrate Invasive Species

Eradication of invasive vertebrate pests from increasingly large islands has become an important wildlife management and conservation tool internationally. Success on islands has prompted attempts to exclude and eradicate vertebrate pests from mainland sites. Early mainland exclusion efforts often failed due to ineffective or poorly maintained barriers to pest reinvasion. Over the last 10 years, we have conducted extensive experiments to design effective pest exclusion technology. We have determined the behavior and physical abilities of many of the vertebrate pest species found in New Zealand and other parts of the world. Pest species have been tested against a variety of …


Robot-In-The-Loop Simulation To Support Multi-Robot System Development: A Dynamic Team Formation Example, Ehsan Azarnasab May 2007

Robot-In-The-Loop Simulation To Support Multi-Robot System Development: A Dynamic Team Formation Example, Ehsan Azarnasab

Computer Science Theses

Modeling and simulation provides a powerful technology for engineers and managers to understand, design, and evaluate a system under development. Traditionally, simulation is only used in early stages of a system design. However, with the advances of hardware and software technology, it is now possible to extend simulation to late stages for supporting a full life cycle simulation-based development. Robot-in-the-loop simulation, where real robots work together with virtual ones, has been developed to support such a development process to bridge the gap between simulation and reality.


Coyote Investigative Behavior Following Removal Of Novel Stimuli, Daniel J. Heffernan, William F. Andelt, John A. Shivik Apr 2007

Coyote Investigative Behavior Following Removal Of Novel Stimuli, Daniel J. Heffernan, William F. Andelt, John A. Shivik

United States Department of Agriculture Wildlife Services: Staff Publications

Because coyotes (Canis latrans) show an aversion to novel objects, we examined the effects of the presence and removal of repellent and attractive stimuli on coyote behavior. We found a greater proportion of captive coyotes investigated 10-cm-tall cones (0.95) compared to 90-cm-tall cones (0.68) and control sites (0.81), and spent longer periods (P , 0.001 in all instances) investigating small cones ( = 465 sec), compared to large cones ( = 212 sec) and control sites ( = 45 sec). However, investigation times at sites following removal of large cones were 1.6 and 2.3 times …


Stalked Crinoid Locomotion, And Its Ecological And Evolutionary Implications, Tomasz K. Baumiller, Charles G. Messing Apr 2007

Stalked Crinoid Locomotion, And Its Ecological And Evolutionary Implications, Tomasz K. Baumiller, Charles G. Messing

Marine & Environmental Sciences Faculty Articles

In the past two decades, much direct evidence has been gathered on active crawling by stalked crinoids, a group generally thought to be sessile. Detailed descriptions of crawling mechanics of isocrinids in aquaria revealed only exceedingly slow movements (~0.1 mm sec-1). Crawling at such speeds severely restricted the range of roles that this behavior could play in stalked crinoid biology and, consequently, in its potential impact on their ecology and evolutionary history. Here, we provide evidence collected in situ by submersible near Grand Bahama Island at a depth of 420 m for a different mode of crawling in …


Operational Challenges Of Solving Urban Coyote Problems In Southern California, Dennis L. Orthmeyer, Terrance A. Cox, John W. Turman, Joe R. Bennett Apr 2007

Operational Challenges Of Solving Urban Coyote Problems In Southern California, Dennis L. Orthmeyer, Terrance A. Cox, John W. Turman, Joe R. Bennett

Wildlife Damage Management Conference Proceedings

We present challenges, methodologies, and solutions related to mitigating urban coyote (Canis latrans) problems in southern California. The physical environment, the diverse urban structure (green belts and parks) with its abundant food resources which support high coyote densities, combined with the human component (behavior, urbanization, politics) create operational challenges. The increasing disconnect between humans and wildlife, coyote emigration/immigration into the increasing rural/urban interface, and coyote life cycles that occur exclusively in urban environments, all contribute to the increase in coyote-human conflicts. California’s southern counties’ human population has expanded 13% over the period from 1990-2000 and is projected to …


Bad Dogs: Why Do Coyotes And Other Canids Become Unruly?, Robert H. Schmidt, Robert M. Timm Apr 2007

Bad Dogs: Why Do Coyotes And Other Canids Become Unruly?, Robert H. Schmidt, Robert M. Timm

Wildlife Damage Management Conference Proceedings

We summarize the behavior of several species of canids (coyotes, dingoes, and gray wolves) in relation to their habituation to humans and to human food sources. Striking parallels exist between coyotes and other wild canids in terms of the inclination of individual animals to act aggressively toward humans and even attack, once they have come to associate humans with food. We describe the stages of coyotes’ behavioral adaptation to suburban ecosystems, listing 7 steps toward increasing habituation, which can be used as action thresholds for invoking active coyote management or removal efforts. We consider the hypothesis that coyotes may regard …


Territorial Behaviour Of Kiang (Equus Kiang Moorcroft, 1841) In Ladakh (India), Natalia V. Paklina, Chris Van Orden Jan 2007

Territorial Behaviour Of Kiang (Equus Kiang Moorcroft, 1841) In Ladakh (India), Natalia V. Paklina, Chris Van Orden

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

The observations of kiang behavior were made in Navokar Valley northeast of Tso Kar Lake (Ladakh, India) between July 30 and November 22, 2001. In the breeding season (end of July until the end of August) adult kiang males kept not overlapping, protected territories (about 10 km2), and marked by single defecation and urination marks. There were adult females with and without offspring on the territories (up to 12 animals, including the male). The distance between male and females on the territories was usually hundred times bigger, then a distance between stallion and his harem in horses. Females …


Remarks On The Social System Of The Mongolian Wild Ass (Equus Hemionus Hemionus), Gertrud Neumann-Denzau, Helmut Denzau Jan 2007

Remarks On The Social System Of The Mongolian Wild Ass (Equus Hemionus Hemionus), Gertrud Neumann-Denzau, Helmut Denzau

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

So far the social system of Mongolian wild asses is non-uniformly interpreted. The authors describe their own observations from different parts of Mongolia and review data from available publications. The arguments support a territorial social system, which agrees with the social system of all other wild asses in Asia and Africa.


Semi-Wild Population Of Kulans In The Bukhara Breeding Centre And Their Co-Habitation With Przewalski’S Horses, Karim Bahloul, Olga B. Pereladova, Natalia V. Soldatova, Ekaterina V. Sidorenko, Antoine J. Sempere Jan 2007

Semi-Wild Population Of Kulans In The Bukhara Breeding Centre And Their Co-Habitation With Przewalski’S Horses, Karim Bahloul, Olga B. Pereladova, Natalia V. Soldatova, Ekaterina V. Sidorenko, Antoine J. Sempere

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

Asiatic wild asses and Przewalski's horses initially inhabited steppe, semi-desert and desert areas, but Przewalski's horses became extinct in the wild, and kulans are under threat of disappearance. The Bukhara Breeding Centre (Uzbekistan) was created in 1976 for conservation and reintroduction of wild ungulate species. In 1977-1978, five kulans (two males and three females) from Barsa-Kelmes Island on the Aral lake were introduced to the reserve. The group increased to 25-30 animals in 1995-1998, when five Przewalski's horses from Moscow and St. Petersburg zoos were introduced to the same territory. We analyzed the home ranges, preferred habitats and social interactions …


Up-Date On The Behaviour And Status Of The Critically Endangered Onager, Equus Hemionus Onager, From Iran, Laurent Tatin, Bijan F. Darreh-Shoori, Christophe Tourenq, David Tatin, Bijan Azmayesh Jan 2007

Up-Date On The Behaviour And Status Of The Critically Endangered Onager, Equus Hemionus Onager, From Iran, Laurent Tatin, Bijan F. Darreh-Shoori, Christophe Tourenq, David Tatin, Bijan Azmayesh

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

The onager, Equus hemionus onager, an Asiatic wild ass endemic to Iran, is categorized as Critically Endangered on the IUCN Red List. Its biology and conservation requirements are poorly documented. We report some observations made in 1997 and 2000 on the behavior and ecology of the two remaining populations, located in the Touran Protected Area and the Bahram-e-Goor Reserve. Recent population counts by the Department of Environment of Iran (471 in the Protected Area, and 96 in the Reserve) are markedly lower than the count of 600-770 made in the 1970s in the Touran Protected Area. We observed social …


Grazing Impacts Of Diverse Zooplankton Taxa On Thin Layers, Alexander Bochdansky Jan 2007

Grazing Impacts Of Diverse Zooplankton Taxa On Thin Layers, Alexander Bochdansky

OES Faculty Publications

The US Navy needs to know how distributions and abundances of light-scattering and sound-scattering organisms in the ocean vary in space and time, particularly in the vertical dimension. Recent field observations have shown that many biological properties may vary substantially over small e.g. centimeter scales, commonly referred to as thin layers e.g. Cowles et al. 1998, 1999, Hanson Donaghay 1998, Holliday et al. 1999, Dekshenieks et al. 2001, Alldredge et al. 2002, Rines et al. 2002. Our previous ONR-funded research has allowed us to begin to understand how zooplankton interact with thin layers and how they can take advantage of …


Development Of Test Paradigms For Operant Conditioning Of Wild Norway Rats, Susan M. Jojola, Patrick W. Burke, Gary W. Witmer, Dale L. Nolte Jan 2007

Development Of Test Paradigms For Operant Conditioning Of Wild Norway Rats, Susan M. Jojola, Patrick W. Burke, Gary W. Witmer, Dale L. Nolte

United States Department of Agriculture Wildlife Services: Staff Publications

Many eradication efforts to remove rats (Rattus spp.) from islands have been successful. Eradications are expensive and labor-intensive which makes early detection of, and response to, reinvasion by rats critical. A better understanding of rat behavior could facilitate early detection and rapid response to intercept invaders, such as with trap placement and design, and toxic bait presentation and dispersal. This was a methods development study of test paradigms to operantly condition wild rats to run on an activity wheel and to press a lever for use in future behavior studies. Operant conditioning is the process of associating specific responses …