Physical Sciences and Mathematics Commons^™

Spatial And Temporal Variation In Cores From Lake Titicaca, Bolivia/Peru During The Last 13,000 Years, Sherilyn C. Fritz, P. A. Baker, P. Tapia, J. Garland

Department of Earth and Atmospheric Sciences: Faculty Publications

We compared the stratigraphy of sediment cores that span the last 13,000 yrs from three sites in the main basin of Lake Titicaca, Boliva/Peru as indicators of regional paleoclimate. The cores show similar patterns of change after ~6,400 calendar yrs before present (cal yr BP) but differ before that time. Site NE98-PC2, which is near the Rio Illave and its delta, shows differences in diatom species composition and in calcium carbonate concentrations relative to cores from the other two sites, particularly during times of inferred high precipitation. In contrast, the carbon isotopic stratigraphy of the three sites is relatively similar. …

A Bayesian Approach For Bandwidth Selection In Kernel Density Estimation With Censored Data, Chinthaka Kuruwita

All Theses

Estimating an unknown probability density function is a common problem arising frequently in many scientific disciplines. Among many density estimation methods, the kernel density estimators are widely used. However, the classical kernel density estimators suffer from an intrinsic problem as they assign positive values outside the support of the target density. This problem is commonly known as the `Spill over` effect. A modification to the regular kernel estimator is proposed to circumvent this problem. The proposed method uses a lognormal kernel and can be used even in the presence of censoring to estimate any density with a positive support without …

On The Use Of Modis Evi To Assess Gross Primary Productivity Of North American Ecosystems, Daniel A. Sims, Abdullah Rahman, Vicente D. Cordova, Bassil Z. El-Masri, Dennis D. Baldocchi, Lawrence B. Flanagan, Allen H. Goldstein, David Y. Hollinger, Laurent Misson, Russell K. Monson, Walter C. Oechel, Hans P. Schmid, Steven C. Wofsy, Liukang Xu

School of Earth, Environmental, & Marine Sciences Faculty Publications

[1] Carbon flux models based on light use efficiency (LUE), such as the MOD17 algorithm, have proved difficult to parameterize because of uncertainties in the LUE term, which is usually estimated from meteorological variables available only at large spatial scales. In search of simpler models based entirely on remote‐sensing data, we examined direct relationships between the enhanced vegetation index (EVI) and gross primary productivity (GPP) measured at nine eddy covariance flux tower sites across North America. When data from the winter period of inactive photosynthesis were excluded, the overall relationship between EVI and tower GPP was better than that between …

Lsuhsc Facilities Daily Update: December 2006, Lsuhsc Property And Facilities Management

LSUHSC Facilities Daily Updates: 2006

LSUHSC Dailly Facilities Updates from December 2006.

These updates describe damage and a timeline of repairs at the LSU Health Sciences Center - New Orleans campus due to Hurricane Katrina which made landfall August 29, 2005.

The Prairie Naturalist, Volume 38, 2006: Reviewers, Author Index, And Subject Index, Elmer J. Finck, Hilary Gillock

The Prairie Naturalist

The list of reviewers, author index, and subject index for volume 38 (2006) of The Prairie Naturalist published by the Great Plains Natural Science Society out of Fort Hays State University in Kansas, United States.

A Statistical Analysis Of Wide Binary Evolution, Kyle Burton Johnston

Theses and Dissertations

Post main sequence (MS) mass loss causes orbital separation amplification in fragile (i.e. common proper motion) binary star systems. Components typically have separations around -1000 a.u. Such wide pairs experience negligible tidal interactions and mass transfer between companions; they evolve as two separate but coeval stars. In this paper we will attempt to model how post-MS mass loss statistically distorts a frequency distribution of fragile binary separations. Understanding this process provides a robust test of current theories of stellar evolution and sets constraints on the dynamics of the Galactic disk.

Conformality And Q-Harmonicity In Carnot Groups, Luca Capogna, Michael Cowling

Mathematics Sciences: Faculty Publications

We show that if f is a 1-quasiconformal map defined on an open subset of a Carnot group G, then composition with f preserves Q-harmonic functions. We combine this with a regularity theorem for Q-harmonic functions and an algebraic regularity theorem for maps between Carnot groups to show that f is smooth. We give some applications to the study of rigidity.

Ahlfors Type Estimates For Perimeter Measures In Carnot-Carathéodory Spaces, Luca Capogna, Nicola Garofalo

Mathematics Sciences: Faculty Publications

We study the relationship between the geometry of hypersurfaces in a Carnot-Carathéodory (CC) space and the Ahlfors regularity of the corresponding perimeter measure. To this end we establish comparison theorems for perimeter estimates between an hypersurface and its tangent space, and between a CC geometry and its "tangent" Carnot group structure.

Local Energy Decay For Solutions Of Multi-Dimensional Isotropic Symmetric Hyperbolic Systems, Thomas C. Sideris, Becca Thomases

Mathematics Sciences: Faculty Publications

The local decay of energy is established for solutions to certain linear, multidimensional symmetric hyperbolic systems, with constraints. The key assumptions are isotropy and nondegeneracy of the associated symbols. Examples are given, including Maxwell's equations and linearized elasticity. Such estimates prove useful in treating nonlinear perturbations.

Linear Conditions Imposed On Flag Varieties, Julianna S. Tymoczko

Mathematics Sciences: Faculty Publications

We study subvarieties of the flag variety called Hessenberg varieties, defined by certain linear conditions. These subvarieties arise naturally in applications including geometric representation theory, number theory, and numerical analysis. We describe completely the homology of Hessenberg varieties over GLn(ℂ) and show that they have no odd-dimensional homology. We provide an explicit geometric construction which partitions each Hessenberg variety into pieces homeomorphic to affine space. We characterize these affine pieces by fillings of Young tableaux and show that the dimension of the affine piece can be computed by combinatorial rules generalizing the Eulerian numbers. We give an equivalent formulation of …

Cuore: An Experiment To Investigate For Neutrinoless Double Beta Decay By Cooling 750 Kg Of Teo2 Crystals At 10 Mk, J. Beeman, M. Dolinski, T.D. Gutierrez, E.E. Haller, R. Maruyama, A.R. Smith, N. Xu, A. Giuliani, M. Pedretti, S. Sangiorgio, M. Barucci, E. Olivieri, L. Risegari, G. Ventura, M Balata, C. Bucci, S. Nisi, E. Palmieri, A. De Waard, E.B. Norman, C. Arnaboldi, C. Brofferio, S. Capelli, F. Capozzi, L. Carbone, M. Clemenza, O Cremonesi, E. Fiorini, C Nones, A. Nucciotti, M. Pavan, G Pessina, S Pirro, E Previtali, M. Sisti, L Torres, L Zanotti, R. Ardito, G. Maier, E. Guardincerri, P Ottonello, M Pallavicini, D.R. Artusa, F. T. Avignone Iii, I. Bandac, R.J. Creswick, H.A. Farach, C. Rosenfeld, S Cebrian, P. Gorla, Ig Irastorza, F Bellini, C Cosmelli, I Dafinei, M Diemoz, F Ferroni, C Gargiulo, E Longo, S Morganti

Physics

CUORE (Cryogenic Underground Observatory for Rare Events) is an experiment proposed to infer the effective Majorana mass of the electron neutrino from measurements on neutrinoless double beta decay (0νDBD). The goal of CUORE is to achieve a background rate in the range 0.001 to 0.01 counts/keV/kg/y at the 0νDBD transition energy of ¹³⁰Te (2528 keV). The proposed experiment, to be mounted in the underground Gran Sasso INFN National Laboratory, Italy, is realized by cooling about 1000 TeO₂ bolometers, of 750 g each, at a temperature of 10mK. We will describe the experiment, to be cooled by an extremely …

Changes In Land Cover And Soil Conditions For The Yabelo District Of The Borana Plateau, 1973-2003, D. Layne Coppock, Sintayehu Mesele, Heluf Gebrekidan, Lemma Gizachew

Environment and Society Faculty Publications

It has been proposed that the Borana Plateau has markedly changed in terms of land cover and land use in recent decades, but no hard data have been available to critically assess this claim. In addition, systematic analysis of soil properties has been limited. Research was designed to measure changes in land cover/land use over 30 years in the 400-km2 Yabelo District of southern Ethiopia using three satellite images taken at an average interval of 15 years. Samples were also collected to assess variation in the physical and chemical properties of dominant soils. Results indicated that Yabelo District has indeed …

Law Of The Sea Cruise To Map The Western Insular Margin And 2500-M Isobath Of Guam And The Northern Mariana Islands. Cruise Report, James V. Gardner

Center for Coastal and Ocean Mapping

U.S. Law of the Sea cruise to map the western insular margin and 2500-m isobath of Guam and the Northern Mariana Islands

CRUISE BD06-1

October 13, to November 12, 2006

Naha, Okinawa, Japan to Apra Harbor, Guam

Acoustic Scattering From Mud Volcanoes And Carbonate Mounts, Charles W. Holland, Thomas C. Weber, Giuseppe Etiope

Center for Coastal and Ocean Mapping

Submarine mud volcanoes occur in many parts of the world’s oceans and form an aperture for gas and fluidized mud emission from within the earth’s crust. Their characteristics are of considerable interest to the geology, geophysics, geochemistry, and underwater acoustics communities. For the latter, mud volcanoes are of interest in part because they pose a potential source of clutter for active sonar. Close-range (single-interaction) scattering measurements from a mud volcano in the Straits of Sicily show scattering10–15dB above the background. Three hypotheses were examined concerning the scattering mechanism: (1) gas entrained in sediment at/near mud volcano, (2) gas bubbles and/or …

From Herd Diversification To Livelihood Diversification As A Response To Poverty: The Case Of The Waso Boran Of Northern Kenya, D. Layne Coppock, Abdullahi D. Jillo, Abdillahi A. Aboud

Environment and Society Faculty Publications

The Waso Boran of northern Kenya used to have large, mobile, and diverse herds of livestock that exploited equally large and diverse rangelands. Forty years of human population growth, drought, environmental change, and lack of relevant policies have altered this situation, however, with the majority of Waso Boran today being livestock poor and engaged in a variety of non-pastoral activities to diversify their livelihoods. One-third of 540 households we surveyed in Isiolo District now have ten head of cattle or less, and a larger census suggests that only 15 percent of households can currently be categorized as mobile pastoralists. The …

Search For Effective Natural Enemies Of Tetranychus Evansi In South And Southeast Brazil, Imeuda P. Furtado, Gilberto J. De Moraes, Serge Kreiter, Markus Knapp

All Peer-Reviewed Publications

Tetranychus evansi Baker & Pritchard is an important pest of Solanaceae in several countries. Introduced accidentally to Africa, it presently occurs in many countries of that continent. In some of them, it is considered a key pest. The suspected area of origin of this mite is South America. The objective of the present study was to identify phytoseiid mites on solanaceous plants in association with T. evansi in south and southeast Brazil for introduction in the African continent for use in a classic biological control program. Almost 1,400 predatory mites of the family Phytoseiidae were collected, on 22 solanaceous species. …

Near-Field Thermal Radiative Transfer And Thermoacoustic Effects From Vapor Plumes Produced By Pulsed Co/Sub 2 /Laser Ablation Of Bulk Water, S. I. Kudryashov, Kevin Lyon, S. D. Allen

Mechanical Engineering - Daytona Beach

Submillimeter deep heating of bulk water by thermal radiation from ablative water plumes produced by a 10.6 μm transversely excited atmospheric C O2 laser and the related acoustic generation has been studied using a contact time-resolved photoacoustic technique. Effective penetration depths of thermal radiation in water were measured as a function of incident laser fluence and the corresponding plume temperatures were estimated. The near-field thermal and thermoacoustic effects of thermal radiation in laser-ablated bulk water and their potential near-field implications are discussed.

c 2006 American Institute of Physics

Collective Action By Women’S Groups To Combat Drought And Poverty In Northern Kenya, D. Layne Coppock, Solomon Desta, Getachew Gebru, Adan Wako, Ibrahim Aden, Chachu Tadecha, Seyoum Tezera

Environment and Society Faculty Publications

Collective action can be an effective means of local development and risk reduction among rural people, but few examples have been documented in pastoral areas. We conducted extensive interviews for 16 women’s groups residing in northern Kenya. Our objectives were to understand how groups were formed, governed, and sustained and what activities they have pursued. The groups we interviewed were 10 years old, on average. Charter memberships averaged about 24 women, 20 of whom were illiterate. Half of the groups formed after facilitation by a development partner and half formed spontaneously. Groups are governed under detailed constitutional frameworks with elected …

Community Perceptions Concerning Key Ecological Resources At Risk In Baringo District, Kenya, D. Layne Coppock, Mark N. Mutinda, Abdillahi A. Aboud

Environment and Society Faculty Publications

Key ecological resources in arid and semi-arid lands are often characterized by small patches of seasonal grazing and important water points that lend critical support to entire production systems. When key resources are degraded or lost, production systems can be badly compromised. The Baringo District of north-central Kenya is well known for enduring decades of environmental degradation and food relief. As an initial part of an effort to map and characterize key ecological resources at risk in Baringo, we interviewed 136 resident leaders from pastoral and agro-pastoral areas. We asked them to identify and rank their most vulnerable ecological resources, …

Public Engagement To Prioritize The Pastoral Research Agenda At The Pastoral And Agro-Pastoral Research Center Of Oari In Ethiopia, D. Layne Coppock, Getachew Gebru, Lemma Gizachew, Sintayehu Mesele, Mohammed Hassena, Solomon Desta

Environment and Society Faculty Publications

The Oromia Agricultural Research Institute (OARI) has a mandate to conduct agricultural and livestock research throughout the Regional State of Oromia in Ethiopia. OARI has recently opened a facility near Yabello town on the Borana Plateau called the Pastoral and Agro-Pastoral Research Center. A meeting was held in August 2006 at Yabello that involved representatives from pastoral communities, the private sector, government, and non-governmental organizations. The aim was to engage stakeholders in a process of problem prioritization and set the stage to create new partnerships to better address pressing problems. The final priorities included: addressing a general decline in forage …

Scaling Tests Of The Cross Section For Deeply Virtual Compton Scattering, C. Muñpz Camacho, A. Camsonne, M. Mazouz, C. Ferdi, G. Gavalian, E. Kuchina, M. Amaryan, K. A. Aniol, M. Beaumel, H. Benaoum, D. Hayes, C. E. Hyde-Wright, H. Ibrahim, P. E. Ulmer, L. B. Weinstein

Physics Faculty Publications

We present the first measurements of the ep → epγ cross section in the deeply virtual Compton scattering (DVCS) regime and the valence quark region. The Q² dependence (from 1.5 to 2.3 GeV²) of the helicity-dependent cross section indicates the twist-2 dominance of DVCS, proving that generalized parton distributions (GPDs) are accessible to experiment at moderate Q². The helicity-independent cross section is also measured at Q²=2.3 GeV². We present the first model-independent measurement of linear combinations of GPDs and GPD integrals up to the twist-3 approximation.

Seasonal Dietary Composition Of The Eastern Coyote (Canis Latrans) On The Berry College Campus In Northwestern Georgia, Kathleen Melissa Owens

Masters Theses and Doctoral Dissertations

Coyotes (Canis latrans) have progressively colonized eastern North America following wolf extirpation and the clearing of forested landscapes. The coyote has expanded its geographic range into Georgia during the past 50 years, and its impact as the top predator is potentially influencing community dynamics via competition and/or predation. Few studies have examined coyote food habits in the southeastern United States. Our objective was to determine prey items consumed by free-ranging coyotes living on Berry College lands in northwestern Georgia. One hundred and twenty-seven coyote scats were collected from May 2005 through August 2006 along seven major service roads that transected …

The Proteomics Of N-Terminal Methionine Cleavage, Frédéric Frottin, Aude Martinez, Philippe Peynot, Sanghamitra Mitra, Richard C. Holz, Carmela Giglione, Thierry Meinnel

Chemistry Faculty Research and Publications

Methionine aminopeptidase (MAP) is a ubiquitous, essential enzyme involved in protein N-terminal methionine excision. According to the generally accepted cleavage rules for MAP, this enzyme cleaves all proteins with small side chains on the residue in the second position (P1′), but many exceptions are known. The substrate specificity of Escherichia coli MAP1 was studied in vitro with a large (>120) coherent array of peptides mimicking the natural substrates and kinetically analyzed in detail. Peptides with Val or Thr at P1′ were much less efficiently cleaved than those with Ala, Cys, Gly, Pro, or Ser in this position. Certain residues …

Two-Loop Bethe Logarithms For Non- S Levels, Ulrich D. Jentschura

Physics Faculty Research & Creative Works

Two-loop Bethe logarithms are calculated for excited P and D states in hydrogenlike systems, and estimates are presented for all states with higher angular momenta. These results complete our knowledge of the P and D energy levels in hydrogen at the order of α⁸ m_ec², where me is the electron mass and c is the speed of light, and scale as Z⁶, where Z is the nuclear charge number. Our analytic and numerical calculations are consistent with the complete absence of logarithmic terms of order (απ)² (Zα)⁶ ln [(Zα)^-2] …

Differential Electron Emission For Single And Multiple Ionization Of Argon By 500 Ev Positrons, Jared M. Gavin, Robert D. Dubois, O. G. De Lucio

Physics Faculty Research & Creative Works

Triply differential electron emission cross sections are measured for single ionization of argon by 500 eV positrons. Data are presented for coincidences between projectiles scattered into angles of 3° and electrons with emission energies less than 10 eV that are observed between 45 and 135° along the beam direction. For interpretation, these are compared to cosine squared representations of the binary and recoil lobes which are convoluted over experimental parameters. Singly differential electron emission data for double and triple ionization by positrons are also presented.

Observation Of Fano Asymmetry In Raman Spectra Of Srtio3 And Cax Sr1-Xtio3 Perovskite Nanocubes, Sarbajit Banerjee, Dae In Kim, Richard D. Robinson, Irving P. Herman, Yuanbing Mao, Stanislaus S. Wong

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Bulk SrTi O3 is cubic and not expected to exhibit any first-order Raman scattering. However, nanocubes of SrTi O3 with an edge length of 80±10 nm show strong first-order Raman scattering originating from the breaking of symmetry caused by frozen surface dipoles (local tetragonality) and the presence of nanoscopic polar domains (arising from incorporated impurities). Rapid polarization fluctuations within these nanoscopic ferroelectric regions interfere with a polar phonon, resulting in a Fano-like asymmetric line shape in these SrTi O3 nanocubes, as well as in Ca0.3 Sr0.7 Ti O3 nanocubes.

Designing Web Sites For Customer Loyalty Across Business Domains: A Multilevel Analysis, S. Mithas, Narayanasamy Ramasubbu, M. S. Krishnan, C. Fornell

Research Collection School Of Computing and Information Systems

Web Sites are important components of Internet strategy for organizations. This paper develops a theoretical model for understanding the effect of Web site design elements on customer loyalty to a Web site. We show the relevance of the business domain of a Web site to gain a contextual understanding of relative importance of Web site design elements. We use a hierarchical linear modeling approach to model multilevel and cross-level interactions that have not been explicitly considered in previous research. By analyzing, data on more than 12,000 online customer surveys for 43 Web sites in several business domains, we find that …

Single Top Quark Production At The Fermilab Tevatron: Threshold Resummation And Finite-Order Soft Gluon Corrections, Nikolaos Kidonakis

Faculty Articles

I present a calculation of threshold soft-gluon corrections to single top-quark production in p(p) collisions via all partonic processes in the t and s channels and via associated top quark and W boson production. The soft-gluon corrections are formally resummed to all orders, and finite-order expansions of the resummed cross section are calculated through next-to-next-to-next-to-leading-order (NNNLO) at next-to-leading logarithmic (NLL) accuracy. Numerical results for single top-quark production at the Tevatron are presented, including the dependence of the cross sections on the top-quark mass and on the factorization and renormalization scales. The threshold corrections in the t channel are small while …

Cheating To Get Better Roommates In A Random Stable Matching, Chien-Chung Huang

Computer Science Technical Reports

This paper addresses strategies for the stable roommates problem, assuming that a stable matching is chosen at random. We investigate how a cheating man should permute his preference list so that he has a higher-ranking roommate probabilistically. In the first part of the paper, we identify a necessary condition for creating a new stable roommate for the cheating man. This condition precludes any possibility of his getting a new roommate ranking higher than all his stable roommates when everyone is truthful. Generalizing to the case that multiple men collude, we derive another impossibility result: given any stable matching in which …

Amphibians And Reptiles In A Mixed-Grass Prairie In Northwestern North Dakota, Robert K. Murphy, Robert F. Danley, Patricia K. Moore

The Prairie Naturalist

There have been almost no surveys of herpetofauna at 109 km² Lostwood National Wildlife Refuge (LNWR) or surrounding counties in northwestern North Dakota, an area possibly undergoing significant environmental change from fossil fuel extraction and use. We used 30 m drift fences to survey amphibian and reptile species in prairie-wetland transition zones at LNWR during mid-May to early-July in 1985 to 1987, and again in 1999 and 2000. We captured only four amphibian and two reptilian species and noted one other reptilian species incidental to our survey. Several species expected to occur in the area were not detected.