883 resultados para Evolutionary path-relinking
Resumo:
Measuring shallow seismic sources provides a way to reveal processes that cannot be directly observed, but the correct interpretation and value of these signals depend on the ability to distinguish source from propagation effects. Furthermore, seismic signals produced by a resonating source can look almost identical to those produced by impulsive sources, but modified along the path. Distinguishing these two phenomena can be accomplished by examining the wavefield with small aperture arrays or by recording seismicity near to the source when possible. We examine source and path effects in two different environments: Bering Glacier, Alaska and Villarrica Volcano, Chile. Using three 3-element seismic arrays near the terminus of the Bering Glacier, we have identified and located both terminus calving and iceberg breakup events. We show that automated array analysis provided a robust way to locate icequake events using P waves. This analysis also showed that arrivals within the long-period codas were incoherent within the small aperture arrays, demonstrating that these codas previously attributed to crack resonance were in fact a result of a complicated path rather than a source effect. At Villarrica Volcano, seismometers deployed from near the vent to ~10 km revealed that a several cycle long-period source signal recorded at the vent appeared elongated in the far-field. We used data collected from the stations nearest to the vent to invert for the repetitive seismic source, and found it corresponded to a shallow force within the lava lake oriented N75°E and dipping 7° from horizontal. We also used this repetitive signal to search the data for additional seismic and infrasonic properties which included calculating seismic-acoustic delay times, volcano acoustic-seismic ratios and energies, event frequency, and real-time seismic amplitude measurements. These calculations revealed lava lake level and activity fluctuations consistent with lava lake level changes inferred from the persistent infrasonic tremor.
Resumo:
The dramatic period of progressive change in Montana that is documented "In the Crucible of Change" series really exploded with the election of Governors Forrest Anderson and Tom Judge. Anderson's single term saw the dispatching of the sales tax as an issue for a long period, the reorganization of the executive branch of state government and the revision of Montana's Constitution. As a former legislator, county attorney, Supreme Court justice, and Attorney General, Anderson brought unmatched experience to the governorship when elected. Tom Judge, although much younger (elected MT’s youngest governor at age 38 immediately following Anderson), also brought serious experience to the governorship: six years as a MT State Representative, two years as a MT State Senator, four years is Lieutenant Governor and significant business experience. The campaign and election of John F. Kennedy in 1960 spurred other young Americans to service, including Tom Judge. First elected in 1960, he rose rapidly through MT’s political-governmental hierarchy until he took over the governorship in time to implement many of the changes started in Governor Anderson’s term. But as a strong progressive leader in his own right, Governor Judge sponsored and implemented significant advancements of his own for Montana. Those accomplishments, however, are the subject of other films in this series. This film deals with Tom Judge’s early years – his rise to the governorship from when he returned home after college at Notre Dame and newspaper experience in Kentucky to his actual election in November 1972. That story is discussed in this episode by three major players in the effort, all directly involved in Tom Judge’s early years and path to the governorship: Sidney Armstrong, Larry Pettit and Kent Kleinkopf. Their recollections of the early Tom Judge and the period of his advancement to the governorship provide an insider’s perspective of the growth of this significant leader of the important period of progressive change documented “In the Crucible of Change.” Sidney Armstrong, President of Sidney Armstrong Consulting, serves on the board and as the Executive Director of the Greater Montana Foundation. Formerly Executive Director of the Montana Community Foundation (MCF), she has served on national committees and participated in national foundation initiatives. While at MCF, she worked extensively with MT Governors Racicot and Martz on the state charitable endowment tax credit and other endowed philanthropy issues. A member of MT Governor Thomas L. Judge’s staff in the 1970s, she was also part of Governor Brian Schweitzer’s 2004 Transition Team, continuing to serve as a volunteer advisor during his term. In the 1980s, Sidney also worked for the MT State AFL-CIO and the MT Democratic Party as well as working two sessions with the MT Senate as Assistant Secretary of the Senate and aide to the President. A Helena native, and great granddaughter of pioneer Montanans, Sidney has served on numerous nonprofit boards, and is currently a board member for the Montana History Foundation. Recently she served on the board of the Holter Museum of Art and was a Governor’s appointee to the Humanities Montana board. She is a graduate of the International School of Geneva, Switzerland and the University of Montana. Armstrong's Irish maternal immigrant great-grandparents, Thomas and Maria Cahill Cooney, came to Virginia City, MT in a covered wagon in 1865, looking for gold. Eventually, they settled on the banks of the Missouri River outside Helena as ranchers. She also has roots in Butte, MT, where her journalist father's family, both of whom were newspaper people, lived. Her father, Richard K. O’Malley, is also the author of a well-known book about Butte, Mile High, Mile Deep, recently re-published by Russell Chatham. She is the mother of four and the grandmother of eight. Dr. Lawrence K. Pettit (Larry Pettit) (b. 5/2/1937) has had a dual career in politics and higher education. In addition to being Montana’s first Commissioner of Higher Education (the subject of another film in this series); Pettit, of Lewistown, served as legislative assistant to U.S. Senators James E. Murray and Lee Metcalf, campaign manager, head of transition team and assistant to Montana Governor Thomas L. Judge; taught political science at The Pennsylvania State University (main campus), was chair of political science at Montana State University, Deputy Commissioner for Academic Programs at the Texas Higher Education Coordinating Board, Chancellor of the University System of South Texas (since merged with Texas A&M University), President of Southern Illinois University, and President of Indiana University of Pennsylvania from where he retired in 2003. He has served as chair of the Commission on Leadership for the American Council on Education, president of the National Association of (University) System Heads, and on many national and state boards and commissions in higher education. Pettit is author of “If You Live by the Sword: Politics in the Making and Unmaking of a University President.” More about Pettit is found at http://www.lawrencekpettit.com… Kent Kleinkopf of Missoula is co-founder of a firm with a national scope of business that specializes in litigation consultation, expert vocational testimony, and employee assistance programs. His partner (and wife of 45 years) Kathy, is an expert witness in the 27 year old business. Kent received a BA in History/Education from the University of Idaho and an MA in Economics from the University of Utah. The Kleinkopfs moved to Helena, MT in 1971 where he was Assistant to the Commissioner of State Lands (later Governor) Ted Schwinden. In early 1972 Kent volunteered full time in Lt. Governor Tom Judge’s campaign for Governor, driving the Lt. Governor extensively throughout Montana. After Judge was elected governor, Kent briefly joined the staff of Governor Forrest Anderson, then in 1973 transitioned to Judge’s Governor’s Office staff, where he became Montana’s first “Citizens’ Advocate.” In that capacity he fielded requests for assistance from citizens with concerns and information regarding State Agencies. While on the Governor’s staff, Kent continued as a travel aide with the governor both in Montana and nationally. In 1977 Kent was appointed Director of the MT Department of Business Regulation. That role included responsibility as Superintendent of Banking and Chairman of the State Banking Board, where Kent presided over the chartering of many banks, savings and loans, and credit unions. In 1981 the Kleinkopfs moved to Missoula and went into the business they run today. Kent was appointed by Governor Brian Schweitzer to the Board of the Montana Historical Society in 2006, was reappointed and continues to serve. Kathy and Kent have a daughter and son-in-law in Missoula.
Evolutionary demography of long-lived monocarpic perennials: a time-lagged integral projection model
Resumo:
1. The evolution of flowering strategies (when and at what size to flower) in monocarpic perennials is determined by balancing current reproduction with expected future reproduction, and these are largely determined by size-specific patterns of growth and survival. However, because of the difficulty in following long-lived individuals throughout their lives, this theory has largely been tested using short-lived species (< 5 years). 2. Here, we tested this theory using the long-lived monocarpic perennial Campanula thyrsoides which can live up to 16 years. We used a novel approach that combined permanent plot and herb chronology data from a 3-year field study to parameterize and validate integral projection models (IPMs). 3. Similar to other monocarpic species, the rosette leaves of C. thyrsoides wither over winter and so size cannot be measured in the year of flowering. We therefore extended the existing IPM framework to incorporate an additional time delay that arises because flowering demography must be predicted from rosette size in the year before flowering. 4. We found that all main demographic functions (growth, survival probability, flowering probability and fecundity) were strongly size-dependent and there was a pronounced threshold size of flowering. There was good agreement between the predicted distribution of flowering ages obtained from the IPMs and that estimated in the field. Mostly, there was good agreement between the IPM predictions and the direct quantitative field measurements regarding the demographic parameters lambda, R-0 and T. We therefore conclude that the model captures the main demographic features of the field populations. 5. Elasticity analysis indicated that changes in the survival and growth function had the largest effect (c. 80%) on lambda and this was considerably larger than in short-lived monocarps. We found only weak selection pressure operating on the observed flowering strategy which was close to the predicted evolutionary stable strategy. 6. Synthesis. The extended IPM accurately described the demography of a long-lived monocarpic perennial using data collected over a relatively short period. We could show that the evolution of flowering strategies in short- and long-lived monocarps seem to follow the same general rules but with a longevity-related emphasis on survival over fecundity.
Resumo:
Vicariance is thought to have played a major role in the evolution of modern parrots. However, as the relationships especially of the African taxa remained mostly unresolved, it has been difficult to draw firm conclusions about the roles of dispersal and vicariance. Our analyses using the broadest taxon sampling of old world parrots ever based on 3219 bp of three nuclear genes revealed well-resolved and congruent phylogenetic hypotheses. Agapornis of Africa and Madagascar was found to be the sister group to Loriculus of Australasia and Indo-Malayasia and together they clustered with the Australasian Loriinae, Cyclopsittacini and Melopsittacus. Poicephalus and Psittacus from mainland Africa formed the sister group Of the Neotropical Arini and Coracopsis from Madagascar and adjacent islands may be the closest relative of Psittrichas from New Guinea. These biogeographic relationships are best explained by independent colonization of the African continent via trans-oceanic dispersal from Australasia and Antarctica in the Paleogene following what may have been vicariance events in the late Cretaceous and/or early Paleogene. Our data support a taxon pulse model for the diversification of parrots whereby trans-oceanic dispersal played a more important role than previously thought and was the prerequisite for range expansion into new continents. (C) 2009 Elsevier Inc. All rights reserved