College of Sciences E-newsletter

October 2007

In this issue:

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Matt Lachniet, assistant professor of geoscience has received a one-year $182,670 grant from the National Science Foundation (182,670)

ABSTRACT: Preliminary results of 14C-dated periglacial ice wedge growth intervals and ä18O profiles suggest that the last glacial climate in Arctic Alaska was characterized by millennial-scale variability. These abrupt events are characterized by alternating ice wedge growth and at least seven thaw periods over the interval of 45,000 to 20,000 yrs BP. A decrease in ice wedge ä18O values with decreasing ice age indicates gradual cooling during cold stadial climates. The hypothesis that these millennial-scale ice-wedge growth/thaw events are arctic manifestations of northern hemisphere stadials and the nine warm Dansgaard/Oeschger events (stadials 3-11) evident in Greenland Ice is evaluated. To test the hypothesis, ice wedges will be dated by 14C of entrapped organic material, and paleoclimate conditions estimated via the generation of ä18O and äD time series, a proxy for winter air temperature. If the hypothesis is correct, it will indicate that the abrupt and severe millennial-scale climate changes strongly manifested in Greenland and the circum-North Atlantic have a hemispheric spatial fingerprint, and highlight the sensitivity of permafrost areas to global climate change on millennial time scales. This research will utilize the unique ground ice record in the Quaternary age permafrost in the CRREL Permafrost Tunnel near Fairbanks, Alaska, under controlled environmental conditions that allow precise sampling in subfreezing temperatures linked to a detailed and rigorous analysis of the sediments and ice and their sedimentary and thermal history.

Broader Impacts: Due to a paucity of paleoclimatic data from arctic and permafrost regions, this work has broader impacts to society by documenting the sensitivity of arctic climate to global climate changes. In particular, few data from the last glacial period are available from arctic environments to calibrate global climate models (GCMs), thus limiting scientists' ability to predict future climate change associated with anthropogenic global warming. Yet the effects of global warming are already documented in Arctic regions where the Inuit, Aleut, Gwich’in and other native cultures, villages and ways of life will be severely affected by large or rapid changes in climate. The detailed stable isotopic analyses of ice wedges and ground ice will provide a high resolution proxy data source for unglaciated regions of the Arctic, filling an important data gap in our understanding of ice-ocean-atmosphere interactions in global climate. Research will be a collaborative effort between a young, emerging scientist, an established federal researcher, and undergraduate and graduate students at Dartmouth College and UNLV; facilities at each institution and CRREL provide necessary cold rooms, Permafrost Tunnel access, mass spectrometric analytical equipment and technical expertise.

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"Millennial-scale Tropical Rainfall Variability From 100 to 20 ka: Testing Cross-Isthmian Water Vapor Transport and Feedbacks on Thermohaline Circulation," National Science Foundation (NSF) Grant ($95,064)

Matt Lachniet, assistant professor of geoscience has received a one-year $95,064 grant from the National Science Foundation.

ABSTRACT: This project investigates the utility of speleothems (i.e., cave deposits) as a means to develop climate proxy data that could help constrain terrestrial rainfall variability, on millennial time scales, with sufficient temporal resolution to evaluate a possible tropical feedback mechanism related to oceanic thermohaline circulation. The general science goals are to constrain the tropical hydrological cycle through evaluation of rainfall amount as a proxy for cross-isthmian water vapor transport, as well as document tropical climate variability over the last 100,000 years.

Specifically, the research team will work to generate high resolution (decadal to multidecadal) oxygen isotope time series, a proxy for tropical rainfall amount, from Uranium series dated stalagmites from Costa Rica and Mexico, sites that are currently under the influence of the Intertropical Convergence Zone (ITCZ). The guiding scientific hypothesis is that tropical rainfall during the last glacial period is dominated by millennial-scale Dansgaard/Oeschger (D/O) variability, which is forced by thermohaline circulation variability and sea surface temperatures in the tropical Atlantic Ocean. The researchers also hypothesize that Heinrich events are associated with deficient rainfall over Central America resulting from a southward displacement of the ITCZ.

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College of Sciences Graduate Admissions Committee (COSGAC)

The newly formed College of Science Graduate Admissions Committee includes faculty, staff and individuals from the college and other campus offices interested in our graduate student admissions practices. COSGAC and its members are charged by the Dean and COS Graduate Coordinators to establish a more uniform graduate student admissions process; to identify, as expeditiously as possible, highly qualified applicants; and to assist in efforts to and retain these students.

COSAG is an effort to respond the desires of our school and departments to:

Improved communication can alleviate a challenges posed by limited infrastructure support and enhance the overall climate for all individuals engaged in graduate admissions. One area of immediate is the recruitment and retention of international students, many of whom apply to UNLV from reputable institutions worldwide and whose applications may be over looked due to misinterpretation of mandatory credentials or qualifications. Liz Gil, Graduate College Evaluator, has agreed to co-chair the COSGAC with Nicholle Booker, M.Ed., Graduate Affairs Coordinator for the College of Sciences. If you would like any additional information regarding the College of Sciences Graduate Admission Committee, please contact Nicholle at: UNLV, College of Sciences, Office of the Dean, Mailstop: 4001; 4505 Maryland Parkway Box 454001, Las Vegas, Nevada 89154; Phone: (702) 895-0871; Fax: (702) 895-4159; Email: Nicholle.Booker@unlv.edu.

Faculty and staff currently participating on COSGAC include:

Liz Gil, Graduate College, Evaluator
Dr. Allen Gibbs, School of Life Sciences, Faculty
Dr. Brian Hedlund, School of Life Sciences, Faculty
Dr. David Hatchett, Department of Chemistry, Faculty
Dr. Ernesto Abel-Santos, Department of Chemistry, Faculty
Mark Miyamoto, Department of Chemistry, Staff
Dr. Andrew Hanson, Department of Geoscience, Faculty
Dr. Lambis.Papelis, Water Resource Management, Faculty
Dr. John Farley, Master of Arts in Science, Faculty
Dr. Ken Czerwinski, Radio Chemistry, Faculty
Dr. Derrick Dubose, Department of Mathematics, Faculty
Dr. Patricia Pablo, Department of Mathematics, Staff
Dr. Zhonghai Ding, Department of Mathematics, Faculty
Dr. Andrew Cornelius, Physics, Faculty
Dr. Lonnie Spight, Physics, Faculty
Natasa Korceba, Physics, Staff
Dr. Andrew Andres, School of Life Sciences, Faculty
Maria Figueroa, Department of Geoscience, Staff
Deborah Masters, Department of Chemistry, Staff
Dr. Victor Kwong, Physic , Faculty

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Wolzinger Family Research Scholarship And Weistrop-Shaffer Scholarship Recipients

Wolzinger Family Research Scholarship

Kahadawala Cooray, Mathematics entered the Mathematics Doctoral Program in 2005. He has successful passed his course work and maintained a high academic standard. In addition to his research, he is a teaching assistant for the Mathematics Department and is a member of the American Statistical Association. His research interest centers on a study of two distributions useful for survival and insurance data analysis. Among his recent publications are:

Cooray, K. (2005). "Analyzing Lifetime Data with Long-Tailed Skewed Distribution: the Logistic-Sinh Family," Statistical Modeling 5, 343-358.

Cooray, K. (2006). "Generalization of the Weibull Distribution: the Odd Weibull Family," Statistical Modeling 6, 265-277.

Cooray, K. and Ananda, M.M.A. (2005). "Modeling Actuarial Data with a Composite Lognormal-Pareto Model," Scandinavian Actuarial Journal 105, 321-334.

Cooray, K., Gunasekera, S., an Ananda, M.M.A. (2006). "The Folded Logistic Distribution," Communications in Statistics-Theory and Methods 35, 385-393.

Weistrop-Shaffer Scholarship

Chrysanthos Kyriakides, Physics and Astronomy, entered the Physics and Astronomy Doctoral Program in 2003. He has successfully passed his course work, maintained a high academic standard and passed his qualifying exams. In addition to his academic course work and research, he is a high school tutor whom specializes in the subjects of physics and calculus. His research interest focuses on hydrongen-deuterium substitution in molecular water ions. Recent publications include:

"Automated Testing Device for Characterizing Etalons," project proposal, Coherent Inc. 2001 (proposal approved and awarded $250,000 for its completion).

"Mestastable State Populations in Laser Induced Plasma," Kwong, Kriakides, Ward. NASA Laboratory Astrophysics Workshop, 2006.

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High Tech Cheating In the News

Dean Ron Yasbin appeared on the August 30th Court TV television show, "Star Jones" to discuss how universities are coping with the technological developments in cheating and plagiarism now in vogue on many campuses. The College of Sciences was previously featured in the New York Times and on CNN for its efforts in engaging our own students to meet this serious challenge to academic integrity.

On September 25, 2007 Dean Ron Yasbin appeared on KNPR Radio. During an interview on the program, "State of Nevada," Yasbin discussed the College of Sciences pro-active efforts to deal with student cheating and plagiarism, efforts that have garners national attention.

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KNPR Interview on Global Warming

On Wednesday, September 12, 2007 assistant professor Matthew Lachniet, Department of Geoscience, was interviewed on KNPR radio in advance of his university forum lecture that evening, entitled, "The Climate History of the Earth: A View to the Future." He discussed the human influence on recent climate change; increasing levels of atmospheric greenhouse gas concentrations due to fossil fuel burning and land clearance, and the evidence used to document the climate of the earth’s past and the implications for the future of our atmosphere here

The interview can be found at: http://www.knpr.org/son/index.cfm

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American Association of Colleges of Osteopathic Medicine

On Thursday, October 4, 2007 UNLV will hosting representatives from twenty schools affiliated with the American Association of Colleges of Osteopathic Medicine. Osteopathic physicians will offer presentations on osteopathic medical philosophy during a panel discussion in the Classroom Building Complex (CBC A-110. A Deans Fair will follow the discussion and allow for specific interactions with admissions officials from each school This event is sponsored by three UNLV student organizations: the Association of Pre-Health Professionals; the Minority Science Students Program; and Alpha Epsilon Delta.

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Geoscience Department Newsletter

The 2007 Summer issue of the Geoscience Department newsletter, including news and information about faculty, staff, students, and alumni is now available online, in addition to many other College of Sciences publications, at:

http://sciences.unlv.edu/publications.html

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Center for Applied Mathematics and Statistics Colloquium

"Numerical Approximation of Stochastic Partial Differential Equations," by Michael D. Marcozzi, Department of Mathematical Sciences, Friday, September 14, 2007, 1:00-2:00 p.m. in CBC-B425a.

Abstract: Many phenomena in control schemes, biology, economics, engineering systems, physics, and other areas can be modeled by partial differential equations with stochastic perturbation terms. The numerical solution of Stochastic Partial Differential Equations (SPDEs) typically relies on (i) simulation or (ii) obtaining a semi-discretization in space and an application of time discretization methods to the resulting initial-value problem with Ito diffusions; both approaches generate a family of sample solutions (realizations) which must be averaged in order to determine the properties of the system. We introduce a hierarchical approximation of Fourier expansions which allows for a deterministic representation of the system’s aggregate properties. Applications from mathematical finance are considered in order to illustrate the approach.

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Chemistry Seminar

Professor emeritus James J. Worman, Rochester Institute of Technology, presented a seminar entitled "Naturally Occurring Organohalogen Compounds- Update 2007," on Friday, September 14t, 2007.

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Statistics Seminar

On Friday, October 12, 2007, 11:00 a.m. - 12:00 p.m. in CBC-C Building, Room 225, professor Junyong Park will present a talk entitled, "Robust Test for Detecting a Signal in a High Dimensional Sparse Normal Vector." Park received a Ph.D. from Purdue University and is currently an assistant professor in the department of mathematics and statistics at University of Maryland, Baltimore. His major research interests include theories and methodologies in multivariate analysis, multiple testing and machine learning in high dimensional data.

Abstract: This presentation considers the problem of testing whether a high dimensional observation vector has signal, i.e., testing all the mean values are zero versus the alternative that non-zero means exist. The conditions are such that the dimension of vector is large, and the mean vector is 'sparse', e.g., the small fraction of mean values is non-zero. Isuggest a test which is not sensitive to the exact tail behavior under normality assumption. In particular, if the 'moderate deviation' tail of the distribution is represented as the product of a tail of a standard normal and a `slowly changing' function, our suggested test is robust. In particular, a need for robust test is expected when the observations are of the normalized form where normality assumption is commonly used from C.L.T.

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Upcoming Seminars

The College of Sciences has established a listserve to better publicize and promote scientific seminars offered throughout the academic year. For more information on upcoming seminars and to subscribe to the listserve, please visit: http://cmse.unlv.edu/seminar/.

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Submit Your News Stories

The College of Sciences E-Newsletter is published on or about the first of each month. Please submit news items via email by the fifteenth of each month, for consideration. You may send your submissions to: Bill Brown, Director of Planning and Communication (william.brown@unlv.edu).

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