Physical Sciences and Mathematics Commons^™

Hydrogeomorphic Segments And Hydraulic Microhabitats Of The Niobrara River, Nebraska, With Special Emphasis On The Niobrara National Scenic River, Jason S. Alexander, Ronald B. Zelt, Nathaniel J. Schaepe

United States Geological Survey: Water Reports and Publications

The Niobrara River is an ecologically and economically important resource in Nebraska. The Nebraska Department of Natural Resources’ recent designation of the hydraulically connected surface- and groundwater resources of the Niobrara River Basin as “fully appropriated” has emphasized the importance of understanding linkages between the physical and ecological dynamics of the Niobrara River so it can be sustainably managed. In cooperation with the Nebraska Game and Parks Commission, the United States Geological Survey USGS) investigated the hydrogeomorphic and hydraulic attributes of the Niobrara River in northern Nebraska. This report presents the results of an analysis of hydrogeomorphic segments and hydraulic …

Perpendicular Ion Heating By Low-Frequency Alfvén-Wave Turbulence In The Solar Wind, Benjamin D. G. Chandran, Bo Li, Barrett N. Rogers, Eliot Quataert, Kai Germaschewski

Dartmouth Scholarship

We consider ion heating by turbulent Alfvén waves (AWs) and kinetic Alfvén waves (KAWs) with wavelengths (measured perpendicular to the magnetic field) that are comparable to the ion gyroradius and frequencies ω smaller than the ion cyclotron frequency Ω. We focus on plasmas in which β < 1, where β is the ratio of plasma pressure to magnetic pressure. As in previous studies, we find that when the turbulence amplitude exceeds a certain threshold, an ion's orbit becomes chaotic. The ion then interacts stochastically with the time-varying electrostatic potential, and the ion's energy undergoes a random walk. Using phenomenological arguments, we derive an analytic expression for the rates at which different ion species are heated, which we test by simulating test particles interacting with a spectrum of randomly phased AWs and KAWs. We find that the stochastic heating rate depends sensitively on the quantity ε = δv _ρ/v _⊥, where v _⊥ (v _∥) is the component of the ion velocity perpendicular (parallel) to the background magnetic field B ₀, and δv _ρ (δB _ρ) is the rms amplitude of the velocity (magnetic-field) fluctuations at the gyroradius scale. In the case …

Water And Poverty In Rural China: Developing An Instrument To Assess The Multiple Dimensions Of Water And Poverty, Alasdair Cohen, Caroline A. Sullivan

Professor Caroline A Sullivan

This paper describes the theoretical foundations and development of a multidimensional, water-focused, thematic indicator of rural poverty: The Water, Economy, Investment and Learning Assessment Indicator (WEILAI). The WEILAI approach was specifically designed for application in rural China, to support poverty alleviation project planning, monitoring and evaluation, as well as targeting and prioritization. WEILAI builds primarily on the basic needs framework of poverty alleviation, and on the methodological structure of the Water Poverty Index, to provide a proxy measure of an area's poverty by assessing eight key poverty sectors, with a strong focus on the components of water-poverty. The WEILAI approach …

Knowing Your Community: Fostering Biodiversity Awareness In Our Students’ Daily Existence, Tony Cummings Bs, Academic Director

Fostering Multicultural Competence and Global Justice: an SIT Symposium

There are strong arguments suggesting that developing students’ sensitivity to local biodiversity and conservation issues is as important as emphasizing an understanding of global conservation issues happening in faraway lands (Ehrenfeld, 2009). Many students arrive at a Study Abroad destination, with a good understanding of theory, but with little field experience at home. Environmental educators in Study Abroad are able to use the novelty and grandeur of our exotic destinations to systematically teach students the patterns and processes of ecological and human communities at our sites, while inspiring a sense of place in our students. By immersing students in the …

Large Mining Projects In The Amazon, Gustavo Negreiros Phd, Academic Director

Fostering Multicultural Competence and Global Justice: an SIT Symposium

In addition to my work coordinating the SIT study abroad program Amazon Resource Management and Human Ecology since 1998, I pursue personal interests in the relation of modern development projects and the social environmental conditions faced by local populations of the region. In 2005, I evaluated the environmental licensing and implementation of Alcoa´s (Aluminum Company of America) mine operation in Juruti, western Pará State, which started operation in 2009. I was invited by the communities impacted and the different actors involved to participate in the team in charge of developing methodologies to valuate the social-environmental externalities faced by the communities, …

Teaching And Learning Process On Renewable Energy And Sustainable Development, Caitlin Brotzmann Ba, Academic Director

Fostering Multicultural Competence and Global Justice: an SIT Symposium

Though the global situation is complex and daunting, education for sustainable development attempts to empower students with the knowledge, values, and ability not only to understand but also to act upon that understanding so that they might create a world in harmony with the environment. In summer 2009, 19 university students from North America came to Iceland to study renewable energy on the SIT Study Abroad (a program of World Learning) program ―Iceland: Renewable Energy, Technology, and Resource Economics.‖ The students traveled around the country, stayed with host families, underwent intensive coursework, visited power plants and policy firms, and conducted …

Environmental Sustainability: Challenges And Opportunities Of Greening Your Study Abroad Program, Sylvia M. Seger Mim, Academic Director

Fostering Multicultural Competence and Global Justice: an SIT Symposium

World Learning’s mission to “… create a more peaceful and just world” by necessity encompasses environmental dynamics, considering that the root causes of most social justice issues and violent conflicts can be traced to environmental degradation and disproportional access to shrinking natural resources. Thus our mission mandates that we employ an ethic of environmental stewardship in all our pursuits and put in place mechanisms to mitigate our environmental impacts.

“We shall never achieve harmony with land, any more than we shall achieve absolute justice or liberty for people. In these higher aspirations, the important thing is not to achieve but …

G-Lattices For An Unrooted Perfect Phylogeny, Monica Grigg

Mathematical Sciences Technical Reports (MSTR)

We look at the Pure Parsimony problem and the Perfect Phylogeny Haplotyping problem. From the Pure Parsimony problem we consider structures of genotypes called g-lattices. These structures either provide solutions or give bounds to the pure parsimony problem. In particular, we investigate which of these structures supports an unrooted perfect phylogeny, a condition that adds biological interpretation. By understanding which g-lattices support an unrooted perfect phylogeny, we connect two of the standard biological inference rules used to recreate how genetic diversity propagates across generations.

A Perturbation Method For Inference On Regularized Regression Estimates, Jessica Minnier, Lu Tian, Tianxi Cai

Harvard University Biostatistics Working Paper Series

No abstract provided.

Torsion In The Cohomology Of Congruence Subgroups Of Sl (4. Z) And Galois Representations, Avner Ash, Paul E. Gunnells, Mark Mcconnell

Paul Gunnells

We report on the computation of torsion in certain homology theories of congruence subgroups of SL(4,Z). Among these are the usual group cohomology, the Tate–Farrell cohomology, and the homology of the sharbly complex. All of these theories yield Hecke modules. We conjecture that the Hecke eigenclasses in these theories have attached Galois representations. The interpretation of our computations at the torsion primes 2, 3, 5 is explained. We provide evidence for our conjecture in the 15 cases of odd torsion that we found in levels ⩽31.

Guest Induced Transformations Of Assembled Pyridyl Bis-Urea Macrocycles, Kinkini Roy, Chun Wang, Mark D. Smith, Mahender B. Dewal, Arief C. Wibowo, Julius C. Brown, Shugo Ma, Linda S. Shimizu

Faculty Publications

Pyridine macrocycles with no cavities assembled into close packed columns yet absorbed guests including hydrogen, carbon dioxide, and iodine.

Interview With Brandon Hill, Bamboo Sushi, 2010 (Audio), Brandon Hill

All Sustainability History Project Oral Histories

Interview of Brandon Hill by Jeff Francoeur at Bamboo Sushi, SE Portland, Oregon on August 10, 2010.

The interview index is available for download.

Aspergillus Fumigatus Sida Is A Highly Specific Ornithine Hydroxylase With Bound Flavin Cofactor, Samuel W. Chocklett, Pablo Sobrado

Chemistry Faculty Research & Creative Works

Ferrichrome is a hydroxamate-containing siderophore produced by the pathogenic fungus Aspergillus fumigatus under iron-limiting conditions. This siderophore contains N5-hydroxylated l-ornithines essential for iron binding. A. fumigatus siderophore A (Af SidA) catalyzes the flavin- and NADPH-dependent hydroxylation of l-ornithine in ferrichrome biosynthesis. Af SidA was recombinantly expressed and purified as a soluble tetramer and is the first member of this class of flavin monooxygenases to be isolated with a bound flavin cofactor. The enzyme showed typical saturation kinetics with respect to l-ornithine while substrate inhibition was observed at high concentrations of NADPH and NADH. Increasing amounts of hydrogen peroxide were measured …

Absorption Of The Ω And Φ Mesons In Nuclei, M. Wood, Gerard P. Gilfoyle, Et. Al.

Physics Faculty Publications

Because of their long lifetimes, the ω and φ mesons are the ideal candidates for the study of possible modifications of the in-medium meson-nucleon interaction through their absorption inside the nucleus. During the E01-112 experiment at the Thomas Jefferson National Accelerator Facility, the mesons were photoproduced from ²H, C, Ti, Fe, and Pb targets. This Letter reports the first measurement of the ratio of nuclear transparencies for the e⁺e^- channel. The ratios indicate larger in-medium widths compared with what have been reported in other reaction channels. The absorption of the ω meson is stronger than that …

Temperature And Variability Of Three Ionian Volcanoes, Daniel R. Allen

Theses and Dissertations

Cassini spacecraft images of Io obtained during its flyby of Jupiter in late 2000 and early 2001 were used to determine the lava composition and eruption style of three faint hotspots, Pillan, Wayland, and Loki. We found a maximum color temperature of 1130+/-289 K for Pillan and maximum color temperatures of 1297+/-289 K and 1387+/-287 K for Wayland and Loki, respectively. These temperatures are suggestive of basaltic lava. The temperatures with the best signal-to-noise ratios also suggested basaltic lava and were found to be 780+/-189 K, 1116+/-250 K, and 1017+/-177 K for Pillan, Wayland, and Loki, respectively. Pillan showed increased …

Interactive Object Selection And Matting For Video And Images, Brian L. Price

Theses and Dissertations

Video segmentation, the process of selecting an object out of a video sequence, is a fundamentally important process for video editing and special effects. However, it remains an unsolved problem due to many difficulties such as large or rapid motions, motion blur, lighting and shadow changes, complex textures, similar colors in the foreground and background, and many others. While the human vision system relies on multiple visual cues and higher-order understanding of the objects involved in order to perceive the segmentation, current algorithms usually depend on a small amount of information to assist a user in selecting a desired object. …

Sumpter, Ward Cullin, 1902-1977 (Sc 2318), Manuscripts & Folklife Archives

Manuscript Collection Finding Aids

Finding aid only for Manuscripts Small Collection 2318. Chemistry notebook of Ward Cullin Sumpter, probably kept about 1930 while he was a doctoral student at Yale University. Includes other miscellaneous documents: a tribute to a church's departing pastor, a draft petition in support of an anti-cigarette law, and a poem relating to the 1928 presidential election.

Distribution Of Health Care Expenditures For Hiv-Infected Patients, Ray Y. Chen, Neil A. Accortt, Andrew O. Westfall, Michael J. Mugavero, James L. Raper, Gretchen A. Cloud, Beth K. Stone, Jerome Carter, Stephanie Call, Maria Pisu, Jeroan J. Allison, Michael S. Saag

Jeroan J. Allison

BACKGROUND: Health care expenditures for persons infected with human immunodeficiency virus (HIV) in the United State determined on the basis of actual health care use have not been reported in the era of highly active antiretroviral therapy.

METHODS: Patients receiving primary care at the University of Alabama at Birmingham HIV clinic were included in the study. All encounters (except emergency room visits) that occurred within the University of Alabama at Birmingham Hospital System from 1 March 2000 to 1 March 2001 were analyzed. Medication expenditures were determined on the basis of 2001 average wholesale price. Hospitalization expenditures were determined on …

Trends In Aids-Defining And Non-Aids-Defining Malignancies Among Hiv-Infected Patients: 1989-2002, Roger Bedimo, Ray Y. Chen, Neil A. Accortt, James L. Raper, Carol Linn, Jeroan J. Allison, John Dubay, Michael S. Saag, Craig J. Hoesley

Jeroan J. Allison

In a comparison of rates of acquired immunodeficiency syndrome (AIDS)-defining malignancies (ADMs) for 1989-1996 versus 1997-2002, we found a decrease in ADMs (rate ratio, 0.31; P<.0001) and a significant increase in non-AIDS-defining malignancies (non-ADMs; rate ratio, 10.87; P<.0002). The mean CD4 cell count was lower among patients with ADMs than among those with non-ADMs. A longer duration of survival during highly active antiretroviral therapy might explain the increasing incidence of non-ADMs.

Dynamic Social Grouping Based Routing In A Mobile Ad-Hoc Network, Roy Cabaniss, Sanjay Madria, George Rush, Abbey Trottay, Srinivasa S. Vulli

Computer Science Faculty Research & Creative Works

The patterns of movement used by Mobile Ad-Hoc networks are application specific, in the sense that networks use nodes which travel in different paths. When these nodes are used in experiments involving social patterns, such as wildlife tracking, algorithms which detect and use these patterns can be used to improve routing efficiency. the intent of this paper is to introduce a routing algorithm which forms a series of social groups which accurately indicate a node's regular contact patterns while dynamically shifting to represent changes to the social environment. With the social groups formed, a probabilistic routing schema is used to …

Defending Wireless Sensor Networks Against Adversarial Localization, Neelanjana Dutta, Abhinav Saxena, Sriram Chellappan

Computer Science Faculty Research & Creative Works

In this paper, we study the issue of defending against adversarial localization in wireless sensor networks. Adversarial localization refers to attacks where an adversary attempts to disclose physical locations of sensors in the network. the adversary accomplishes this by physically moving in the network while eavesdropping on communication messages exchanged by sensors and measuring raw physical properties of messages like Angle of Arrival, Signal Strength of the detected signal. in this paper, we aim to defend sensor networks against such kinds of adversarial localization. the core challenge comes from the sensors performing two conflicting objectives simultaneously: localize the adversary and …

Performance Analysis Of Secure Hierarchical Data Aggregation In Wireless Sensor Networks, Vimal Kumar, Sanjay Madria

Computer Science Faculty Research & Creative Works

Data aggregation is a technique used to conserve battery power in wireless sensor networks (WSN). While providing security in such a scenario it is also important that we minimize the number of security operations as they are computationally expensive, without compromising on the security. in this paper we evaluate the performance of such an end-to-end security algorithm. We provide our results from the implementation of the algorithm on mica2 motes and conclude how it is better than traditional hop by hop security. © 2010 IEEE.

Real-Time Data Compression In Wireless Sensor Networks, Tommy Szalapski, Sanjay Madria

Computer Science Faculty Research & Creative Works

Wireless sensor networks possess significant limitations in storage, bandwidth, and power. Additionally, real-time sensor networks cannot tolerate high latency. While some good compression algorithms exist specific to sensor networks, there remains a need for methods that do not introduce additional latency. This paper introduces a compression scheme which reduces storage, bandwidth, and power while also minimizing latency. Our Huffman style compression scheme exploits temporal locality and delta compression to provide better bandwidth utilization, thus reducing latency for real time applications. © 2010 IEEE.

Efficient Simulation Architecture For Routing And Replication In Mobile Peer To Peer Network Of Uavs, Hemanth Meka, Sanjay Kumar Madria, Mohan Kumar, Mark Linderman, Sharma Chakravarthy

Computer Science Faculty Research & Creative Works

Most of the routing and replication algorithms assume the network to be large and therefore, the architecture and algorithms are designed to be scalable. These algorithms however may not perform well with limited number of nodes in a network of UAVs. It is better to design and simulate such algorithms to increase the efficiency in a small network as scalability is no longer an issue. for such networks, we present design and simulation of some effective routing and replication algorithms to route packets, disseminate information, and replicate data among nodes. © 2010 IEEE.

A Communication Efficient Framework For Finding Outliers In Wireless Sensor Networks, Dylan Mcdonald, Stewart Sanchez, Sanjay Kumar Madria, Fikret Ercal

Computer Science Faculty Research & Creative Works

Outlier detection is a well-studied problem in various fields. the unique challenges of wireless sensor networks make this problem especially challenging. Sensors can detect outliers for a plethora of reasons and these reasons need to be inferred in real time. Here, we present a new communication technique to find outliers in a wireless sensor network. Communication is minimized through controlling sensor when sensors are allowed to communicate. at the same time, minimal assumptions are made about the nature of the data set as to minimize the loss of generality in the architecture. © 2010 IEEE.

Chain-Selective And Regioselective Ethylene And Styrene Dimerization Reactions Catalyzed By A Well-Defined Cationic Ruthenium-Hydride Complex: New Insights On The Styrene Dimerization Mechanism, Do W. Lee, Chae S. Yi

Chemistry Faculty Research and Publications

The cationic ruthenium hydride complex [(η⁶-C₆H₆)(PCy₃)(CO)RuH]⁺BF₄⁻ was found to be a highly regioselective catalyst for the ethylene dimerization reaction to give 2-butene products (TOF = 1910 h⁻¹, >95% selectivity for 2-butenes). The dimerization of styrene exclusively produced the head-to-tail dimer (E)-PhCH(CH₃)CH═CHPh at an initial turnover rate of 2300 h⁻¹. A rapid and extensive H/D exchange between the vinyl hydrogens of styrene-d₈ and 4-methoxystyrene was observed within 10 min without forming the dimer products at room temperature. The inverse …

Synthesis And In Vitro Binding Of N,N-Dialkyl-2-Phenylindol-3-Ylglyoxylamides For The Peripheral Benzodiazepine Binding Sites, T. P. Homes, F. Mattner, Paul A. Keller, A. Katsifis

Paul Keller

A series of N,N-dialkyl-2-phenylindol-3-ylglyoxylamides bearing the halogens iodine and bromine were synthesised and their binding affinity for the peripheral benzodiazepine binding sites (PBBS) in rat kidney mitochondrial membranes were evaluated using [3H]-PK11195. Central benzodiazepine receptor (CBR) affinities were also evaluated in rat cortices using 3H-flumazenil to determine their selectivity for PBBS over CBR. The tested compounds had PBBS binding affinities (IC50) ranging from 7.86 nM to 618 nM, with all compounds showing high selectivity over the CBR (CBR IC50 > 5000 nM). Among the 12 compounds tested, those with a diethylamide group were the most potent. The highest affinity iodinated PBBS …

Synthesis Of Some Cyclic Indolic Peptoids As Potential Antibacterials, Vicki S. Au, John B. Bremner, Jonathan Coates, Paul A. Keller, Stephen G. Pyne

Paul Keller

The synthesis of cyclic peptoids containing an indole hydrophobic scaffold has been realised through the ring-closing metathesis of diallylated precursors. The precursors and their cyclic counterparts possessed poor antibacterial activity in contrast to previously reported cyclic peptoids containing hydrophobic scaffolds.

[60]Fullerene Amino Acids And Related Derivatives, Glenn A. Burley, Paul A. Keller, Stephen G. Pyne

Paul Keller

This paper is a review of the literature concerning the preparation of [60]fullerene amino acid and peptide derivatives. The structure and applications of these derivatives to the biological and material sciences is also presented.

Reactions Of Iminoglycines With C60 Fullerene And Their Unambiguous Characterisation Using Nmr Spectroscopy, Paul A. Keller, Stephen G. Pyne, Bill C. Hawkins

Paul Keller

This review examines the addition of iminoglycine derivatives to C60, yielding protected fullerenyl pyrroline derivatives. Subsequent reduction with sodium cyanoborohydride produces ring-opening adducts which are protected fullerenyl α-amino acids. Pyrroline bisadducts can be produced using tethers to link two iminoglycine units together, and variations include combining with malonate reactive groups this giving rise to interesting observations as to the regioselectivity of such reactions. All derivatives are fully characterised by NMR spectroscopy, and in the case of bis-adducts, the regioselectivity is determined from 1H/13C and 13C/13C connectivity patterns using HMBC and INADEQUATE experiments, respectively, thus eliminating the need for comparative techniques …