Digital Commons Network^™

Re-Defining The Empirical Zz Ceti Instability Strip, Anjum S. Mukadam, Ted Von Hippel, D. E. Winget,, M. H. Montgomery

Publications

We use the new ZZ Ceti stars (hydrogen atmosphere white dwarf variables; DAVs) discovered within the Sloan Digital Sky Survey (Mukadam et al. 2004) to re-define the empirical ZZ Ceti instability strip. This is the first time since the discovery of white dwarf variables in 1968 that we have a homogeneous set of spectra acquired using the same instrument on the same telescope, and with con- sistent data reductions, for a statistically significant sample of ZZ Ceti stars. The homogeneity of the spectra reduces the scatter in the spectroscopic temperatures and we find a narrow instability strip of width ∼ …

Data-Model Comparison Search Analysis Of Coincident Pbo Balmer Α, Eurd Lyman Β Geocoronal Measurements From March 2000, J. Bishop, E. J. Mierkiewicz, F. L. Roesler, J. F. Gómez, C. Morales

Publications

Recent Lyman series and Balmer series airglow measurements provide a fresh opportunity to investigate the density distribution and variability of atomic hydrogen in the upper atmosphere. Dedicated nightside Balmer α Fabry-Perot spectrometer measurements at the Pine Bluff Observatory (PBO), University of Wisconsin-Madison, have been acquired since late 1999 taking advantage of several technological advances. Extreme ultraviolet spectral radiance measurements by the Espectrógrafo Ultravioleta extremo para la Radiación Difusa (EURD) instrument on the Spanish MINISAT-1 satellite from October 1997 to December 2001 provide extensive sets of geocoronal Lyman β, Lyman γ and He 584 Å emission intensities. In this paper, coincident …

Interstellar H3+ Line Absorption Toward Lkhα 101, Sean D. Brittain, Theodore Simon, Craig Kulesa, Terrence W. Rettig

Publications

We present a detection of three lines of the H+3 ion in the near-infrared spectrum of the Herbig Be star LkHalpha 101. H+3 is the principal initiator of gas-phase chemistry in interstellar clouds and can be used to constrain the ionization rate or the path length through interstellar material along the line of sight. Essentially all of the observed H+3 column of (2.2+/-0.3)×1014 cm-2 toward LkHalpha 101 originates in the same dense, dark cloud; less than 1 mag of the ~11 total magnitudes of visual extinction is attributable to diffuse material. Constraints on the density [1×104cm-3

Accuracy And Precision Of Age Estimates For Pallid Sturgeon From Pectoral Fin Rays, Keith L. Hurley, Robert J. Sheehan, Roy C. Heidinger

Publications

Accurate age information is critical to the biological understanding and management of most fish species, but particularly for species of concern, such as the pallid sturgeon Scaphirhynchus albus. The accuracy and precision of pallid sturgeon age estimates from pectoral fin ray sections has never been established, yet all accumulated age information for the species was collected using this technique. To examine the accuracy and precision of age estimates, 16 pectoral fin ray samples from age-6 pallid sturgeon were obtained from Gavins Point National Fish Hatchery, South Dakota. The fin rays were sectioned, mounted, and independently examined twice by each …

Spectroscopic And Photometric Analysis Of Hs 1136+6646: A Hot Young Dao+K7 V Post-Common-Envelope, Pre-Cataclysmic Variable Binary, D. K. Sing, Terry D. Oswalt, J. B. Holberg, M. R. Burleigh, S. A. Good, Et Al.

Publications

Extensive photometric and spectroscopic observations have been obtained for HS 1136+6646. The observations reveal a newly formed post–common-envelope binary system containing a hot ~DAO.5 primary and a highly irradiated secondary. HS 1136+6646 is the most extreme example yet of a class of short-period hot H-rich white dwarfs with K–M companion systems such as V471 Tau and Feige 24. HS 1136+6646 is a double-line spectroscopic binary showing emission lines of H i, He ii, C ii, Ca ii, and Mg ii, due in part to irradiation of the K7 V secondary by the hot white dwarf. Echelle spectra reveal the hydrogen …

Beryllium Abundances In F And G Dwarfs In Praesepe And Other Young Clusters From Keck Hires Observations, Ann Merchant Boesgaard, Eric Armengaud, Jeremy R. King

Publications

The study of both Be and Li gives useful clues about stellar internal structure. Of particular interest is the study of these light elements in open clusters, which have a known age and metallicity. In this paper we present a study of Be abundances in 10 F-type stars in Praesepe and a comprehensive discussion about Be abundances in other open clusters: Hyades, Pleiades, Per, Coma, and UMa. We have made observations of the doublet of Be ii around 3130 A˚ in Praesepe stars, using the Keck I telescope and the High Resolution Echelle Spectrometer (HIRES). Beryllium abundances were derived from …

Uaa Student Showcase Journal: Recognizing Excellence (2004), N/A N/A

Publications

No abstract provided.

On Polynomial Transformations For Simulating Multivariate Non-Normal Distributions, Todd C. Headrick

Publications

Procedures are introduced and discussed for increasing the computational and statistical efficiency of polynomial transformations used in Monte Carlo or simulation studies. Comparisons are also made between polynomials of order three and five in terms of (a) computational and statistical efficiency, (b) the skew and kurtosis boundary, and (c) boundaries for Pearson correlations. It is also shown how ranked data can be simulated for specified Spearman correlations and sample sizes. Potential consequences of nonmonotonic transformations on rank correlations are also discussed.

, Monte Carlo methods, polynomial transformations, nonnormality

Breaking The Cycle: Die Another Day, Post-Colonialism, And The James Bond Film Series, Walter C. Metz

Publications

No abstract provided.

Assessment Of Floating Vertical Raceways For The Culture Of Phase-Ii Hybrid Striped Bass, Eric T. Volkman, Christopher C. Kohler, Susan T. Kohler

Publications

A floating vertical raceway is a system designed to provide a constant, unidirectional flow of water to fish confined in a flexible raceway that is suspended vertically in the water column. This study evaluated the potential of floating vertical raceways for the culture of phase-II sunshine bass (female white bass Morone chrysops × male striped bass M. saxatilis) reared at two densities (125 and 188 fish/m³). Fish with a mean starting weight of 0.7 g were fed a diet containing 40% crude protein to satiation for 121 d. Fish in the low-density treatment reached a significantly higher …

Predicting Learning From Asynchronous Online Discussions, Dezhi Wu, Starr Roxanne Hiltz

Publications

Online discussions play an important role in student learning. Currently, asynchronous learning courses and some primarily face-to-face courses at New Jersey Institute of Technology require asynchronous online discussions. Does this requirement improve the students' perceived learning? An exploratory study designed to investigate this issue was conducted in Spring 2002. The questionnaire drew responses to a post-course questionnaire from 116 students in two undergraduate courses and one graduate course. A set of items designed to measure perceived learning from online discussions formed a reliable, unidimensional index for this construct. The results indicate that online discussions do improve students' perceived learning. Variations …

Interacting Near-Solutions Of A Hamiltonian System, Gregory S. Spradlin

Publications

A Hamiltonian system with a superquadratic potential is examined. The system is asymptotic to an autonomous system. The difference between the Hamiltonian system and the “problem at infinity,” the autonomous system, may be large, but decays exponientially. The existence of a nontrivial solution homoclinic to zero is proven. Many results of this type rely on a monotonicity condition on the nonlinearity, not assumed here, which makes the problem resemble in some sense the special case of homogeneous (power) nonlinearity. The proof employs variational, minimax arguments. In some similar results requiring the monotonicity condition, solutions inhabit a manifold homeomorphic to the …

Bilaterian Phylogeny Based On Analyses Of A Region Of The Sodium-Potassium Atpase Beta-Subunit Gene, Frank E Anderson, Alonso J Córdoba, Mikael Thollesson

Publications

Molecular investigations of deep-level relationships within and among the animal phyla have been hampered by a lack of slowly evolving genes that are amenable to study by molecular systematists. To provide new data for use in deep-level metazoan phylogenetic studies, primers were developed to amplify a 1.3-kb region of the alpha subunit of the nuclear-encoded sodium-potassium ATPase gene from 31 bilaterians representing several phyla. Maximum parsimony, maximum likelihood, and Bayesian analyses of these sequences (combined with ATPase sequences for 23 taxa downloaded from GenBank) yield congruent trees that corroborate recent findings based on analyses of other data sets (e.g., the …

Oxygen In Open Cluster Dwarfs: Pleiades And M34, Simon C. Schuler, Jeremy R. King, L M. Hobbs, Marc H. Pinsonneault

Publications

We analyze the high-excitation O I lambda7774 triplet in high-resolution, moderate signal-to-noise ratio spectra of 15 Pleiades and eight M34 open cluster dwarfs over the effective temperature range of 5048-6172 K. Relative O abundances have been derived using model atmospheres interpolated from four different sets of ATLAS9 grids. In contrast to existing non-LTE (NLTE) predictions, a dramatic increase in the O I triplet abundance with decreasing temperature is seen for both clusters, regardless of the atmospheric model. S I abundances of three Pleiades stars derived from the high-excitation lambda6053 feature mimic the O I abundance behavior. O abundances have also …

Use Of Ultrasound Imaging To Determine Sex Of Shovelnose Sturgeon, Robert E. Colombo, Paul S. Wills, James E. Garvey

Publications

During November 2002, 51 shovelnose sturgeon Scaphirhynchus platorynchus were sexed by ultrasound imaging using a portable ultrasonograph. We identified males with 96% accuracy (N = 25) and females with 80% accuracy (N = 25); one hermaphroditic individual was misidentified as a male. Overall, ultrasound imaging was 86% accurate. Sex in postspawned females was difficult to determine, 60% being misidentified as males (N = 5). Ultrasonography is an effective noninvasive method for sex determination that can be applied to other species of Acipenseriformes. Modern portable equipment expands its utility to field studies.

Daily Increment Formation In Otoliths Of The Redspotted Sunfish, Matt E. Roberts, James E. Wetzel Ii, Ronald C. Brooks, James E. Garvey

Publications

To generate reliable age information for fishes, we must assess the robustness of techniques to environmental variation. We quantified daily ring deposition within the sagittal otoliths of known-age larval and juvenile redspotted sunfish Lepomis miniatus reared in ponds. We also determined how daily light : dark cycles mimicking natural conditions, reduced daylight, or constant daylight affected ring deposition in fish housed in aquaria. Additionally, we quantified how constant temperature (26°C), low daily variability in temperature (26 ± 1°C), and high daily variability (26 ± 2°C) affected production of daily rings. In pond-reared fish, the first increment was produced by the …

Existence Of Solutions To A Hamiltonian System Without Convexity Condition On The Nonlinearity, Gregory S. Spradlin

Publications

We study a Hamiltonian system that has a superquadratic potential and is asymptotic to an autonomous system. In particular, we show the existence of a nontrivial solution homoclinic to zero. Many results of this type rely on a convexity condition on the nonlinearity, which makes the problem resemble in some sense the special case of homogeneous (power) nonlinearity. This paper replaces that condition with a different condition, which is automatically satisfied when the autonomous system is radially symmetric. Our proof employs variational and mountain-pass arguments. In some similar results requiring the convexity condition, solutions inhabit a submanifold homeomorphic to the …

In Vivo Targeting Of Antigens To Maturing Dendritic Cells Via The Dec-205 Receptor Improves T Cell Vaccination, Laura C. Bonifaz, David P. Bonnyay, Anna Charalambous

Publications

The prevention and treatment of prevalent infectious diseases and tumors should benefit from improvements in the induction of antigen-specific T cell immunity. To assess the potential of antigen targeting to dendritic cells to improve immunity, we incorporated ovalbumin protein into a monoclonal antibody to the DEC-205 receptor, an endocytic receptor that is abundant on these cells in lymphoid tissues. Simultaneously, we injected agonistic α-CD40 antibody to mature the dendritic cells. We found that a single low dose of antibody-conjugated ovalbumin initiated immunity from the naive CD4⁺ and CD8⁺ T cell repertoire. Unexpectedly, the αDEC-205 antigen conjugates, given s.c., …

Cd25+ Cd4+ T Cells, Expanded With Dendritic Cells Presenting A Single Autoantigenic Peptide, Suppress Autoimmune Diabetes, Kristin V. Tarbell, Sayuri Yamazaki, Kara D. Olson

Publications

In the nonobese diabetic (NOD) mouse model of type 1 diabetes, the immune system recognizes many autoantigens expressed in pancreatic islet β cells. To silence autoimmunity, we used dendritic cells (DCs) from NOD mice to expand CD25⁺ CD4⁺ suppressor T cells from BDC2.5 mice, which are specific for a single islet autoantigen. The expanded T cells were more suppressive in vitro than their freshly isolated counterparts, indicating that DCs from autoimmune mice can increase the number and function of antigen-specific, CD25⁺ CD4⁺ regulatory T cells. Importantly, only 5,000 expanded CD25⁺ CD4⁺ BDC2.5 T cells …

The Linkage Of Innate To Adaptive Immunity Via Maturing Dendritic Cells In Vivo Requires Cd40 Ligation In Addition To Antigen Presentation And Cd80/86 Costimulation, Shinichiro Fujii, Kang Z. Liu, Carol L. Smith

Publications

Dendritic cell (DC) maturation is an innate response that leads to adaptive immunity to coadministered proteins. To begin to identify underlying mechanisms in intact lymphoid tissues, we studied α-galactosylceramide. This glycolipid activates innate Vα14⁺ natural killer T cell (NKT) lymphocytes, which drive DC maturation and T cell responses to ovalbumin antigen. Hours after giving glycolipid i.v., tumor necrosis factor (TNF)-α and interferon (IFN)-γ were released primarily by DCs. These cytokines induced rapid surface remodeling of DCs, including increased CD80/86 costimulatory molecules. Surprisingly, DCs from CD40^-/- and CD40L^-/- mice did not elicit CD4+ and CD8⁺ T cell …

Indirect Mobilization: The Social Consequences Of Party Contacts In An Election Campaign, Scott D. Mcclurg

Publications

Although direct contacts between campaigns and individuals are a central part of the process that encourages political participation, it is often argued that their effects extend beyond the initial contact via a secondary process of indirect mobilization. This paper puts that argument to the test by investigating possible connections between direct party contacts and political mobilization in social networks. The results show that the primary social consequence of party contacts is to alter the substance, but not the volume, of politically oriented conversations that occur in social networks. These conversations in turn increase the salience of the campaign in the …

A Tradition Of Scholarship In Natural Resources Law, David Getches

Publications

Introduction to the Natural Resources Issue of the University of Colorado Law Review, Vol. 75, No. 2 (Winter 2004).

New Leadership For Libraries: Who Has The Right Stuff?, Eric C. Shoaf

Publications

No abstract provided.

Speech Perception In Noise: Directional Microphones Versus Frequency Modulation (Fm) Systems, M Samantha Lewis, Carl C. Crandall, Michael Valente, Jane Enrietto Horn

Publications

No abstract provided.

Regional Forest Types - Tropical Dry Forests, Skip Van Bloem, Ariel E. Lugo, Peter G. Murphy

Publications

Tropical dry forests occur in nearly every tropical country. This forest type provides critical habitat for large mammals and migratory birds, and patches of dry forest can support a high proportion of endemic plant and animal species, as well as being highly valued for agricultural and production forestry uses. Consequently, conservation and understanding of these forests need emphasis, yet conservationists and scientists still frequently overlook this ecosystem.

A Turn To Engineering: The Continuing Struggle Of Technology Education For Legitimization As A School Subject, Theodore Lewis

Publications

In the long march from manual training, the subject which today we call technology education has always had to contend with the question of its legitimacy as valid school knowledge. In this regard, it shares a similar history of struggle with other subjects whose initial entry into the curriculum was based on a utilitarian rather than an academic rationale. Goodson (1983) documents such cases (e.g. geography and biology) showing how in their struggle for acceptance, the primary strategy of advocates was to try to enhance the academic bona fides of their subject. He explained that utilitarian knowledge is associated with …

Hindlimb Function In The Alligator: Integrating Movements, Motor Patterns, Ground Reaction Forces And Bone Strain Of Terrestrial Locomotion, Stephen M. Reilly, Jeffrey S. Wiley, Audrone R. Biknevicius, Richard W. Blob

Publications

Alligator hindlimbs show high torsional loads during terrestrial locomotion, in sharp contrast to the bending or axial compressive loads that predominate in animals that use parasagittal limb movements. The present study integrates new data on hindlimb muscle function with previously obtained data on hindlimb kinematics, motor patterns, ground reaction forces and bone strain in order to (1) assess mechanisms underlying limb bone torsion during non-parasagittal locomotion in alligators and (2) improve understanding of hindlimb dynamics during terrestrial locomotion. Three dynamic stance phase periods were recognized: limb-loading, support-and-propulsion, and limb-unloading phases. Shear stresses due to torsion were maximized during the limb-loading …

Restoration Of Southern Ecosystems, William Conner, John A. Stanturf, Emile S. Gardiner, Kenneth Outcalt, James M. Guldin

Publications

Restoration of the myriad communities of bottomland hardwood and wetland forests and of the diverse communities of fire-dominated pine forests is the subject of intense interest in the Southern United States. Restoration practice is relatively advanced for bottomland hardwoods and longleaf pine (Pinus palustris Mill.), and less so for swamps and shortleaf pine (P. echinata Mill.). Most bottomland hardwood restoration is taking place on private land, while restoration of swamps and shortleaf pine occurs mostly on public land. Both public and private landowners are involved in the restoration of longleaf pine. Proper matching of species to site is critical to …

Siviculture And Management Strategies Applicable To Southern Hardwoods, William Conner, Ray R. Hicks Jr, Robert C. Kellison, David Vanlear

Publications

Southern hardwood forests stretch from the Virginias to Florida and from the mid-Atlantic to Missouri. They can generally be grouped into upland forests and bottomland forests. The upland hardwood forests of the southern region are usually associated with the mountainous topography of the Appalachians and Ozarks. Bottomland hardwoods are found along the floodplains of larger rivers in the Atlantic and Gulf Coastal Plains, including the Mississippi River floodplain. Southern hardwood forests are owned by a variety of governmental and private owners, but the vast majority of owners are nonindustrial private individuals. These owners seldom engage in intensive forest management, often …

Growth And Survival Of Baldcypress Planted In An Old Ricefield Of Coastal South Carolina, William Conner, L W. Inabinette, M Ozalp

Publications

Vast acreages of baldcypress [Taxodium distichum (L.) Rich.] swampland in coastal South Carolina were cleared for rice production starting in the late 1600s. When rice cultivation ended in the late 1800s, many cultivated areas became
marshlands. Other fields failed to return to forest unless they were planted. In one such area, nine acres were planted with baldcypress in 1956 by MeadWestvaco near Walterboro, SC. Seedlings were planted on an 8- by 8-foot spacing. Beginning in November 1991, five 0.12-acre plots were established within the stand to monitor tree growth and survival and measured yearly. In addition to baldcypress, the stand …