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41.
We investigate the use of landforms at different scales by males of the territorial nymphalid butterfly Inachis io (Linnaeus, 1758) under different weather conditions. They are known to use landforms at two different scales including macroscale, such as valley sides, tops of slopes and wood edges, and mini-landforms, such as molehills produced by the burrowing animal Talpa europaea Linnaeus (Linnaeus, 1758). Here, we demonstrate that they exploit microscale features on the molehills. The butterfly shifts its position in the landscape in relation to changing conditions by flying, and at the microscale, by walking. The links between thermoregulatory behavior and site selection indicate that perches are adopted to maintain body heat in the cool spring conditions when territories are established. Mini-landforms such as the molehills are adopted for their potential shelter and warmth in relation to ambient conditions; microsite selection typically includes warm niches on molehills, such as sunny slopes, sheltered margins and depressions. Shelter is adopted regardless of reduced visibility for territorial males. The importance of non-consumable (mate location) resources at different spatial scales is discussed in the context of habitat and the matrix. 相似文献
42.
Bruce Stockley rew B. Smith Tim Littlewood Harilaos A. Lessios & Jacqueline A. Mackenzie-Dodds 《Zoologica scripta》2005,34(5):447-468
A phylogeny for 21 species of spatangoid sea urchins is constructed using data from three genes and results compared with morphology-based phylogenies derived for the same taxa and for a much larger sample of 88 Recent and fossil taxa. Different data sets and methods of analysis generate different phylogenetic hypotheses, although congruence tests show that all molecular approaches produce trees that are congruent with each other. By contrast, the trees generated from morphological data differ significantly according to taxon sampling density and only those with dense sampling (after a posteriori weighting) are congruent with molecular estimates. With limited taxon sampling, secondary reversals in deep-water taxa are interpreted as plesiomorphies, pulling them to a basal position. The addition of fossil taxa with their unique character combinations reveals hidden homoplasy and generates a phylogeny that is compatible with molecular estimates. As homoplasy levels were found to be broadly similar across different anatomical structures in the echinoid test, no one suite of morphological characters can be considered to provide more reliable phylogenetic information. Some traditional groupings are supported, including the grouping of Loveniidae, Brissidae and Spatangidae within the Micrasterina, but the Asterostomatidae is shown to be polyphyletic with members scattered amongst at least five different clades. As these are mostly deep-sea taxa, this finding implies multiple independent invasions into the deep sea. 相似文献
43.
Tim Salditt 《生物化学与生物物理学报:生物膜》2006,1758(9):1483-1498
The conformation and correlations of amphiphilic and antimicrobial peptides and the associated changes of lipid bilayers can be studied in oriented lipid membranes deposited on solid substrates. Here we review recent work on these systems, as studied by modern interface-sensitive X-ray and neutron scattering methods. Density profile, short range order of acyl chains and molecular conformations of peptides and lipids are probed in the fluid state of the bilayer. With an emphasis on technical aspects, we review recent work illustrating the potential of the methods and discuss its potential in the field. 相似文献
44.
45.
A flexible multi-dimensional QoS performance measure framework for distributed heterogeneous systems
Jong-Kook Kim Debra A. Hensgen Taylor Kidd Howard Jay Siegel David St. John Cynthia Irvine Tim Levin N. Wayne Porter Viktor K. Prasanna Richard F. Freund 《Cluster computing》2006,9(3):281-296
When users’ tasks in a distributed heterogeneous computing environment (e.g., cluster of heterogeneous computers) are allocated
resources, the total demand placed on some system resources by the tasks, for a given interval of time, may exceed the availability
of those resources. In such a case, some tasks may receive degraded service or be dropped from the system. One part of a measure
to quantify the success of a resource management system (RMS) in such a distributed environment is the collective value of
the tasks completed during an interval of time, as perceived by the user, application, or policy maker. The Flexible Integrated
System Capability (FISC) measure presented here is a measure for quantifying this collective value. The FISC measure is a
flexible multi-dimensional measure such that any task attribute can be inserted and may include priorities, versions of a
task or data, deadlines, situational mode, security, application- and domain-specific QoS, and task dependencies. For an environment
where it is important to investigate how well data communication requests are satisfied, the data communication request satisfied
can be the basis of the FISC measure instead of tasks completed. The motivation behind the FISC measure is to determine the
performance of resource management schemes if tasks have multiple attributes that needs to be satisfied. The goal of this
measure is to compare the results of different resource management heuristics that are trying to achieve the same performance
objective but with different approaches.
This research was supported by the DARPA/ITO Quorum Program, by the DARPA/ISO BADD Program and the Office of Naval Research
under ONR grant number N00014-97-1-0804, by the DARPA/ITO AICE program under contract numbers DABT63-99-C-0010 and DABT63-99-C-0012,
and by the Colorado State University George T. Abell Endowment. Intel and Microsoft donated some of the equipment used in
this research.
Jong-Kook Kim is pursuing a Ph.D. degree from the School of Electrical and Computer Engineering at Purdue University (expected in August
2004). Jong-Kook received his M.S. degree in electrical and computer engineering from Purdue University in May 2000. He received
his B.S. degree in electronic engineering from Korea University, Seoul, Korea in 1998. He has presented his work at several
international conferences and has been a reviewer for numerous conferences and journals. His research interests include heterogeneous
distributed computing, computer architecture, performance measure, resource management, evolutionary heuristics, and power-aware
computing. He is a student member of the IEEE, IEEE Computer Society, and ACM.
Debra Hensgen is a member of the Research and Evaluation Team at OpenTV in Mountain View, California. OpenTV produces middleware for set-top
boxes in support of interactive television. She received her Ph.D. in the area of Distributed Operating Systems from the University
of Kentucky. Prior to moving to private industry, as an Associate Professor in the systems area, she worked with students
and colleagues to design and develop tools and systems for resource management, network re-routing algorithms and systems
that preserve quality of service guarantees, and visualization tools for performance debugging of parallel and distributed
systems. She has published numerous papers concerning her contributions to the Concurra toolkit for automatically generating
safe, efficient concurrent code, the Graze parallel processing performance debugger, the SAAM path information base, and the
SmartNet and MSHN Resource Management Systems.
Taylor Kidd is currently a Software Architect for Vidiom Systems in Portland Oregon. His current work involves the writing of multi-company
industrial specifications and the architecting of software systems for the digital cable television industry. He has been
involved in the establishment of international specifications for digital interactive television in both Europe and in the
US. Prior to his current position, Dr. Kidd has been a researcher for the US Navy as well as an Associate Professor at the
Naval Postgraduate School. Dr Kidd received his Ph.D. in Electrical Engineering in 1991 from the University of California,
San Diego.
H. J. Siegel was appointed the George T. Abell Endowed Chair Distinguished Professor of Electrical and Computer Engineering at Colorado
State University (CSU) in August 2001, where he is also a Professor of Computer Science. In December 2002, he became the first
Director of the CSU Information Science and Technology Center (ISTeC). ISTeC is a university-wide organization for promoting,
facilitating, and enhancing CSU’s research, education, and outreach activities pertaining to the design and innovative application
of computer, communication, and information systems. From 1976 to 2001, he was a professor at Purdue University. He received
two BS degrees from MIT, and the MA, MSE, and PhD degrees from Princeton University. His research interests include parallel
and distributed computing, heterogeneous computing, robust computing systems, parallel algorithms, parallel machine interconnection
networks, and reconfigurable parallel computer systems. He has co-authored over 300 published papers on parallel and distributed
computing and communication, is an IEEE Fellow, is an ACM Fellow, was a Coeditor-in-Chief of the Journal of Parallel and Distributed
Computing, and was on the Editorial Boards of both the IEEE Transactions on Parallel and Distributed Systems and the IEEE
Transactions on Computers. He was Program Chair/Co-Chair of three major international conferences, General Chair/Co-Chair
of four international conferences, and Chair/Co-Chair of five workshops. He has been an international keynote speaker and
tutorial lecturer, and has consulted for industry and government.
David St. John is Chief Information Officer for WeatherFlow, Inc., a weather services company specializing in coastal weather observations
and forecasts. He received a master’s degree in Engineering from the University of California, Irvine. He spent several years
as the head of staff on the Management System for Heterogeneous Networks project in the Computer Science Department of the
Naval Postgraduate School. His current relationship with cluster computing is as a user of the Regional Atmospheric Modeling
System (RAMS), a numerical weather model developed at Colorado State University. WeatherFlow runs RAMS operationally on a
Linux-based cluster.
Cynthia Irvine is a Professor of Computer Science at the Naval Postgraduate School in Monterey, California. She received her Ph.D. from
Case Western Reserve University and her B.A. in Physics from Rice University. She joined the faculty of the Naval Postgraduate
School in 1994. Previously she worked in industry on the development of high assurance secure systems. In 2001, Dr. Irvine
received the Naval Information Assurance Award. Dr. Irvine is the Director of the Center for Information Systems Security
Studies and Research at the Naval Postgraduate School. She has served on special panels for NSF, DARPA, and OSD. In the area
of computer security education Dr. Irvine has most recently served as the general chair of the Third World Conference on Information
Security Education and the Fifth Workshop on Education in Computer Security. She co-chaired the NSF workshop on Cyber-security
Workforce Needs Assessment and Educational Innovation and was a participant in the Computing Research Association/NSF sponsored
Grand Challenges in Information Assurance meeting. She is a member of the editorial board of the Journal of Information Warfare
and has served as a reviewer and/or program committee member of a variety of security related conferences. She has written
over 100 papers and articles and has supervised the work of over 80 students. Professor Irvine is a member of the ACM, the
AAS, a life member of the ASP, and a Senior Member of the IEEE.
Timothy E. Levin is a Research Associate Professor at the Naval Postgraduate School. He has spent over 18 years working in the design, development,
evaluation, and verification of secure computer systems, including operating systems, databases and networks. His current
research interests include high assurance system design and analysis, development of models and methods for the dynamic selection
of QoS security attributes, and the application of formal methods to the development of secure computer systems.
Viktor K. Prasanna received his BS in Electronics Engineering from the Bangalore University and his MS from the School of Automation, Indian
Institute of Science. He obtained his Ph.D. in Computer Science from the Pennsylvania State University in 1983. Currently,
he is a Professor in the Department of Electrical Engineering as well as in the Department of Computer Science at the University
of Southern California, Los Angeles. He is also an associate member of the Center for Applied Mathematical Sciences (CAMS)
at USC. He served as the Division Director for the Computer Engineering Division during 1994–98. His research interests include
parallel and distributed systems, embedded systems, configurable architectures and high performance computing. Dr. Prasanna
has published extensively and consulted for industries in the above areas. He has served on the organizing committees of several
international meetings in VLSI computations, parallel computation, and high performance computing. He is the Steering Co-chair
of the International Parallel and Distributed Processing Symposium [merged IEEE International Parallel Processing Symposium
(IPPS) and the Symposium on Parallel and Distributed Processing (SPDP)] and is the Steering Chair of the International Conference
on High Performance Computing(HiPC). He serves on the editorial boards of the Journal of Parallel and Distributed Computing
and the Proceedings of the IEEE. He is the Editor-in-Chief of the IEEE Transactions on Computers. He was the founding Chair
of the IEEE Computer Society Technical Committee on Parallel Processing. He is a Fellow of the IEEE.
Richard F. Freund is the originator of GridIQ’s network scheduling concepts that arose from mathematical and computing approaches he developed
for the Department of Defense in the early 1980’s. Dr. Freund has over twenty-five years experience in computational mathematics,
algorithm design, high performance computing, distributed computing, network planning, and heterogeneous scheduling. Since
1989, Dr. Freund has published over 45 journal articles in these fields. He has also been an editor of special editions of
IEEE Computer and the Journal of Parallel and Distributed Computing. In addition, he is a founder of the Heterogeneous Computing
Workshop, held annually in conjunction with the International Parallel Processing Symposium. Dr. Freund is the recipient of
many awards, which includes the prestigious Department of Defense Meritorious Civilian Service Award in 1984 and the Lauritsen-Bennet
Award from the Space and Naval Warfare Systems Command in San Diego, California. 相似文献
46.
47.
Johanna V. Weiss Jeremy A. Rentz Todd Plaia Scott C. Neubauer Melissa Merrill-Floyd Tim Lilburn 《Geomicrobiology journal》2013,30(7-8):559-570
Iron deposits (Fe plaque) on wetland plant roots contain abundant microbial populations, including Fe(II)-oxidizing bacteria (FeOB) that have not been cultured previously. In this study, 4 strains of Fe plaque-associated FeOB were isolated from 4 species of wetland plants. All 4 isolates grew in tight association with Fe-oxides, but did not form any identifiable Fe-oxide structures. All strains were obligate lithotrophic Fe(II)-oxidizers that were microaerobic, and were unable to use other inorganic or organic energy sources. One strain, BrT, was shown to fix 14 CO 2 at a rate consistent with its requirement for total cell carbon. The doubling times for the strains varied between 9.5 and 15.8 hours. The fatty acid methyl ester (FAME) profiles of 2 strains, BrT and CCJ, revealed that 16:0, 15:1 isoG, and 14:0 were dominant fatty acids. Phylogenetic analysis of the 16S rRNA gene indicated that all the strains were Betaproteobacteria. Two of the strains, BrT and Br-1 belong to a new species, Sideroxydans paludicola; a third strain, LD-1, is related to Sideroxydans lithotrophicus, a recently described species of FeOB. The fourth isolate, Ferritrophicum radicicola, represented a new genus in a new order of Betaproteobacteria, the Ferritrophicales. There are no other cultured isolates in this order. A small subunit rRNA gene-based, cultivation-independent analysis of Typha latifolia collected from a wetland revealed terminal restriction fragment profiles (tRFLP) consistent with the presence of these bacteria in the rhizosphere. These novel organisms likely play an important role in Fe(II) oxidation kinetics and Fe cycling within many terrestrial and freshwater environments. 相似文献
48.
Bin Liu Guangbin Ye Fengpin Wang Ryan Bell John Noakes Tim Short 《Geomicrobiology journal》2013,30(6):363-369
Microorganisms play fundamental roles in the ecosystem of the Gulf of Mexico (GOM), yet their vertical distributions along the depth continuum of water column are not well known. In this study, we presented the 16S rDNA sequences and lipid profiles in the context of water chemistry to characterize the archaeal community structure above a gas hydrate mound (MC 118) in GOM. Our results showed that all archaeal sequences were related to unknown species of Crenarchaeota or Euryarchaeota. Phylogenetically, group II –β Euryarchaeota dominated the surface water and mid-depth (400-m) water (74% and 58% of total archaeal species, respectively) whereas the marine group I-γ Crenarchaeota dominated the bottom (869 m) water (61% of total archaeal species). Estimates of the Shannon index showed the highest diversity of planktonic Archaea at the 400 m depth. Glycerol dialkyl glycerol tetraether (GDGT) lipids were detected from the 400- and 869-m depths only and characterized by relatively high abundances of GDGT-5 (crenarchaeol) and GDGT-0. Our studies suggested a possible zonation of archaeal community in the water column, which did not seem to be affected by the possible venting of hydrocarbons from the hydrate location in GOM. 相似文献
49.
50.
Marion L?sing Ingo Goldbeck Birgit Manno Thomas Oellerich Tim Schnyder Hanibal Bohnenberger Bj?rn Stork Henning Urlaub Facundo D. Batista Jürgen Wienands Michael Engelke 《The Journal of biological chemistry》2013,288(4):2303-2313
Recruitment of the growth factor receptor-bound protein 2 (Grb2) by the plasma membrane-associated adapter protein downstream of kinase 3 (Dok-3) attenuates signals transduced by the B cell antigen receptor (BCR). Here we describe molecular details of Dok-3/Grb2 signal integration and function, showing that the Lyn-dependent activation of the BCR transducer kinase Syk is attenuated by Dok-3/Grb2 in a site-specific manner. This process is associated with the SH3 domain-dependent translocation of Dok-3/Grb2 complexes into BCR microsignalosomes and augmented phosphorylation of the inhibitory Lyn target SH2 domain-containing inositol 5′ phosphatase. Hence, our findings imply that Dok-3/Grb2 modulates the balance between activatory and inhibitory Lyn functions with the aim to adjust BCR signaling efficiency. 相似文献