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Gravity Wave Ducting In The Upper Mesosphere And Lower Thermosphere Duct System, R. L. Walterscheid, Michael P. Hickey Ph.D. Oct 2009

Gravity Wave Ducting In The Upper Mesosphere And Lower Thermosphere Duct System, R. L. Walterscheid, Michael P. Hickey Ph.D.

Publications

We report on a numerical study of gravity wave propagation in a pair of ducts located in a region where dramatic changes in the airglow most likely associated with ducted wave trains are observed. We examine ducting in an upper mesosphere inversion (INV) and an always present lower thermosphere stable layer (LTD) for a range of phase speeds and horizontal wavelengths characteristic of ducting events. We analyze the propagation and modal structure of ducted waves for backgrounds with increasing realism, starting with a climatological temperature profile where only the LTD is present. In succession, we add the INV based on …

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Volumetric Flank Wear Characterization For Titanium Milling Insert Tools, Uli Burger, Mathew Kuttolamadom, April Bryan, Laine Mears, Thomas Kurfess Oct 2009

Volumetric Flank Wear Characterization For Titanium Milling Insert Tools, Uli Burger, Mathew Kuttolamadom, April Bryan, Laine Mears, Thomas Kurfess

Publications

Machining wear models are useful for the prediction of tool life and the estimation of machining productivity. Existing wear models relate the cutting parameters of feed, speed, and depth of cut to tool wear. The tool wear is often reported as changes in flank width or crater depth. However, these one-dimensional wear measurements do not fully characterize the tool condition when tools wear by other types of wear such as notching, chipping, and adhesion. This is especially true when machining difficult-to-machine materials such as titanium. This paper proposes another approach for characterizing tool wear. It is based on taking measurements …

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Seven New Species Of Cephennium Muller & Kunze (Coleptera, Staphylinidae, Scymaeninae, Cephenniini) From California With A Key To Native North American Species, Michael S. Caterino, Katie J. Hopp Oct 2009

Seven New Species Of Cephennium Muller & Kunze (Coleptera, Staphylinidae, Scymaeninae, Cephenniini) From California With A Key To Native North American Species, Michael S. Caterino, Katie J. Hopp

Publications

Seven new species of Cephennium from California are described and illustrated - C. celsifrons, sp. n., C. mariposae, sp. n., C. grandarboreum, sp. n., C. canestroi, sp. n., C. gilberti, sp. n., C. urbanum, sp. n. and C. aridum, sp. n. Th e single known native Nearctic species, C. anophthalmicum Brendel, was known only from moist coastal forests around the San Francisco Bay area. Th e new species greatly expand the distribution of the genus, through central and southern California, occurring in the central Sierra Nevada, south through the coast ranges and Sierra Nevada to the Santa Monica Mountains and …

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Profiles Of Urban, Low Ses, African American Girls’ Attitudes Toward Science: A Sequential Explanatory Mixed Methods Study, Gayle Buck, Kristin Cook, Cassie F. Quigley, Jennifer Eastwood, Yvonne Lucas Oct 2009

Profiles Of Urban, Low Ses, African American Girls’ Attitudes Toward Science: A Sequential Explanatory Mixed Methods Study, Gayle Buck, Kristin Cook, Cassie F. Quigley, Jennifer Eastwood, Yvonne Lucas

Publications

The purpose of this study was to increase the science education community’s understanding of the experiences and needs of girls who cross the traditional categorical boundaries of gender, race and socioeconomic status in a manner that has left their needs and experience largely invisible. A first of several in a series, this study sought to explore how African American girls from low SES communities position themselves in science learning. We followed a mixed-methods sequential explanatory strategy, in which two data collection phases, qualitative following the quantitative, were employed to investigate 89 African-American girls’ personal orientations towards science learning. By using …

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Spatial Dynamics Of Nesting Behavior: Lizards Shift Microhabitats To Construct Nests With Beneficial Thermal Properties, Michael W. Sears, Michael J. Angilletta, Robert M. Pringle Oct 2009

Spatial Dynamics Of Nesting Behavior: Lizards Shift Microhabitats To Construct Nests With Beneficial Thermal Properties, Michael W. Sears, Michael J. Angilletta, Robert M. Pringle

Publications

Because temperature affects the growth, development, and survival of embryos,
oviparous mothers should discriminate carefully among available nesting sites. We combined a radiotelemetric study of animal movements with a spatial mapping of environmental temperatures to test predictions about the nesting behavior of the eastern fence lizard (Sceloporus undulatus). Females made large excursions from their typical home ranges to construct nests in exposed substrates. These excursions appeared to be related solely to nesting because all females returned to forested habitat immediately afterward. On average, 1% (range ¼ 0–8%, n ¼ 19) of the area used by a female during nesting was …

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The Pars Triangularis In Dyslexia And Adhd: A Comprehensive Approach., Michelle Y. Kibby, Judith M Kroese, Hillery Krebbs, Crystal E Hill, George W Hynd Oct 2009

The Pars Triangularis In Dyslexia And Adhd: A Comprehensive Approach., Michelle Y. Kibby, Judith M Kroese, Hillery Krebbs, Crystal E Hill, George W Hynd

Publications

Limited research has been conducted on the structure of the pars triangularis (PT) in dyslexia despite functional neuroimaging research finding it may play a role in phonological processing. Furthermore, research to date has not examined PT size in ADHD even though the right inferior frontal region has been implicated in the disorder. Hence, one of the purposes of this study was to examine the structure of the PT in dyslexia and ADHD. The other purposes included examining the PT in relation to overall expressive language ability and in relation to several specific linguistic functions given language functioning often is affected …

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Saturated Lipid Sources In Feeds For Sunshine Bass: Alterations In Production Performance And Tissue Fatty Acid Composition, Jesse T. Trushenski Oct 2009

Saturated Lipid Sources In Feeds For Sunshine Bass: Alterations In Production Performance And Tissue Fatty Acid Composition, Jesse T. Trushenski

Publications

Feeds rich in saturated (SFAs) and monounsaturated fatty acids (MUFA) appear to maximize the retention of long-chain polyunsaturated fatty acids (LC-PUFA) in the fillets of sunshine bass (female white bass Morone chrysops × male striped bass M. saxatilis). To determine whether different sources of SFA and MUFA have equivalent effects on tissue fatty acid (FA) profile change, coconut (CO) and palm oils(PO) were evaluated as partial and complete substitutes for fish oil (FO) in feeds for juvenile sunshine bass. After 8 weeks of culture, the production performance of all groups was within the acceptable range for sunshine bass; however, …

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Wither Print Journals, Eric C. Shoaf Oct 2009

Wither Print Journals, Eric C. Shoaf

Publications

An introduction to the journal is presented in which the editor discusses the journal's transition from print to online-only format. In addition, some of the subjects covered in the issue are presented including participatory management, employee orientation and assessing library services.

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Magnetic, Magnetocaloric, And Magnetoelastic Properties Of Lafe(11.57)Si(1.43)B(X) Compounds, Arjun K. Pathak, Prakash Basnyat, Igor Dubenko, Shane Stadler, Naushad Ali Sep 2009

Magnetic, Magnetocaloric, And Magnetoelastic Properties Of Lafe(11.57)Si(1.43)B(X) Compounds, Arjun K. Pathak, Prakash Basnyat, Igor Dubenko, Shane Stadler, Naushad Ali

Publications

We have studied the magnetic, magnetocaloric, and magnetoelastic properties of LaFe11.57Si1.43Bx compounds in the concentration interval 0<x ≤ 1.64 using magnetization and strain gauge techniques. The crystal cell parameters and Curie temperatures were found to increase linearly with increasing B concentrations up to ∼ 0.1% and 9%, respectively. A positive magnetovolume anomaly of about 0.22% was observed in the vicinity of TC. The magnetovolume coupling constant was estimated to be approximately 3×10−3 [μB/Fe atom]−2. Magnetic entropy changes at TC slightly depended on B concentration. A …

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Ontogenetic Patterns Of Agonistic Behavior In A Guild Of Larval Ambystomatid Salamanders, Cy L. Mott, Donald W. Sparling Sep 2009

Ontogenetic Patterns Of Agonistic Behavior In A Guild Of Larval Ambystomatid Salamanders, Cy L. Mott, Donald W. Sparling

Publications

Agonistic behavior is a common feature of larval amphibians inhabiting temporary ponds. Given the temporally staggered sequence of hatching by pond-breeding amphibians, ontogenetic patterns of aggression can influence coexistence if larvae of certain species or ages are subject to increased aggression. To determine whether aggression changes through larval ontogeny, we observed agonistic behavior of Ambystoma opacum, Ambystoma tigrinum, and Ambystoma maculatum at four stages of development spanning the larval period. We tracked aggression rates among individual larvae to determine whether previous success, in the form of increased aggression, facilitated success in subsequent contests. All species exhibited distinct ontogenetic …

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Accelerating Sift On Parallel Architectures, Amy Apon, Seth Warn, Wesley Emeneker, Jackson Cothren Sep 2009

Accelerating Sift On Parallel Architectures, Amy Apon, Seth Warn, Wesley Emeneker, Jackson Cothren

Publications

SIFT is a widely-used algorithm that extracts features from images; using it to extract information from hundreds of terabytes of aerial and satellite photographs requires parallelization in order to be feasible. We explore accelerating an existing serial SIFT implementation with OpenMP parallelization and GPU execution.

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Weibel Instability And Associated Strong Fields In A Fully 3d Simulation Of A Relativistic Shock, K.-I. Nishikawa, J. Niemiec, P. E. Hardee, M. Medvedev, H. Sol, Y. Mizuno, B. Zhang, M. Pohl, M. Oka, Dieter H. Hartmann Aug 2009

Weibel Instability And Associated Strong Fields In A Fully 3d Simulation Of A Relativistic Shock, K.-I. Nishikawa, J. Niemiec, P. E. Hardee, M. Medvedev, H. Sol, Y. Mizuno, B. Zhang, M. Pohl, M. Oka, Dieter H. Hartmann

Publications

Plasma instabilities (e.g., Buneman, Weibel and other two-stream instabilities) excited in collision-less shocks are responsible for particle (electron, positron, and ion) acceleration. Using a new 3-D relativistic particle-in-cell code, we have investigated the particle acceleration and shock structure associated with an unmagnetized relativistic electron-positron jet propagating into an unmagnetized electron-positron plasma. The simulation has been performed using a long simulation system in order to study the nonlinear stages of the Weibel instability, the particle acceleration mechanism, and the shock structure. Cold jet electrons are thermalized and slowed while the ambient electrons are swept up to create a partially developed hydrodynamic …

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Analysis And Modeling Of Ducted And Evanescent Gravity Waves Observed In The Hawaiian Airglow, D. B. Simkhada, J. B. Snively, M. J. Taylor, S. J. Franke Aug 2009

Analysis And Modeling Of Ducted And Evanescent Gravity Waves Observed In The Hawaiian Airglow, D. B. Simkhada, J. B. Snively, M. J. Taylor, S. J. Franke

Publications

Short-period gravity waves of especially-small horizontal scale have been observed in the Maui, Hawaii airglow. Typical small-scale gravity wave events have been investigated, and intrinsic wave propagation characteristics have been calculated from simultaneous meteor radar wind measurements. Here we report specific cases where wave structure is significantly determined by the local wind structure, and where wave characteristics are consistent with ducted or evanescent waves throughout the mesopause region. Two of the documented events, exhibiting similar airglow signatures but dramatically different propagation conditions, are selected for simple numerical modeling case studies. First, a Doppler-ducted wave trapped within relatively weak wind flow …

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Propagation Of Tsunami-Driven Gravity Waves Into The Thermosphere And Ionosphere, Michael P. Hickey, G. Schubert, R. L. Walterscheid Aug 2009

Propagation Of Tsunami-Driven Gravity Waves Into The Thermosphere And Ionosphere, Michael P. Hickey, G. Schubert, R. L. Walterscheid

Publications

Recent observations have revealed large F-region electron density perturbations (~100%) and total electron content (TEC) perturbations (~30%) that appear to be correlated with tsunamis. The characteristic speed and horizontal wavelength of the disturbances are ~200 m/s and ~400 km. We describe numerical simulations using our spectral full-wave model (SFWM) of the upward propagation of a spectrum of gravity waves forced by a tsunami, and the interaction of these waves with the F-region ionosphere. The SFWM describes the propagation of linear, steady-state acoustic-gravity waves in a nonisothermal atmosphere with the inclusion of eddy and molecular diffusion of heat and momentum, ion …

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Stellar Nucelosynthesis In The Hyades Open Cluster, Simon C. Schuler, Jeremy R. King, Lih-Sin The Aug 2009

Stellar Nucelosynthesis In The Hyades Open Cluster, Simon C. Schuler, Jeremy R. King, Lih-Sin The

Publications

We report a comprehensive light element (Li, C, N, O, Na, Mg, and Al) abundance analysis of three solar-type main sequence (MS) dwarfs and three red giant branch (RGB) clump stars in the Hyades open cluster using high-resolution and high signal-to-noise spectroscopy. For each group (MS or RGB), the CNO abundances are found to be in excellent star-to-star agreement. Our results confirm that the giants have undergone the first dredge-up and that material processed by the CN cycle has been mixed to the surface layers. The observed abundances are compared to predictions of a standard stellar model based on the …

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Tracing The Inner Edge Of The Disk Around Hd 100546 With Rovibrational Co Emission Lines, Sean D. Brittain, Joan R. Najita, John S. Carr Aug 2009

Tracing The Inner Edge Of The Disk Around Hd 100546 With Rovibrational Co Emission Lines, Sean D. Brittain, Joan R. Najita, John S. Carr

Publications

In this paper we present high-resolution 4.7 μm spectra of the isolated Herbig Be star HD 100546. HD 100546 has been the subject of intense scrutiny because it is a young nearby star with a transitional disk. We observe the Δv = 1 rovibrational CO transitions in order to clarify the distribution of warm gas in the inner disk. Modeling of the CO spectrum indicates that the gas is vibrationally excited by collisions and UV fluorescence. The observed emission extends from 13 to 100 AU. The inner edge of the molecular gas emission is consistent with the inner edge of …

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Developing Abrasion Test Standards For Evaluating Lunar Construction Materials, Ryan L. Kobrick, David M. Klaus, Kenneth W. Street Jul 2009

Developing Abrasion Test Standards For Evaluating Lunar Construction Materials, Ryan L. Kobrick, David M. Klaus, Kenneth W. Street

Publications

Operational issues encountered by Apollo astronauts relating to lunar dust were catalogued, including material abrasion that resulted in scratches and wear on spacesuit components, ultimately impacting visibility, joint mobility and pressure retention. Standard methods are being developed to measure abrasive wear on candidate construction materials to be used for spacesuits, spacecraft, and robotics. Calibration tests were conducted using a standard diamond stylus scratch tip on the common spacecraft structure aluminum, Al 6061-T6. Custom tips were fabricated from terrestrial counterparts of lunar minerals for scratching Al 6061-T6 and comparing to standard diamond scratches. Considerations are offered for how to apply standards …

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Errands Into The Metropolis: New England Dissidents In Revolutionary London, Jonathan Beecher Field Jul 2009

Errands Into The Metropolis: New England Dissidents In Revolutionary London, Jonathan Beecher Field

Publications

Errands into the Metropolis offers a dramatic new interpretation of the texts and contexts of early New England literature. Jonathan Beecher Field inverts the familiar paradigm of colonization as an errand into the wilderness to demonstrate, instead, that New England was shaped and re-shaped by a series of return trips to a metropolitan London convulsed with political turmoil. In London, dissidents and their more orthodox antagonists contended for colonial power through competing narratives of their experiences in the New World. Dissidents showed a greater willingness to construct their narratives in terms that were legible to a metropolitan reader than did …

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Revealing The Structure Of A Pre-Transitional Disk: The Case Of The Herbig F Star Sao 206462 (Hd 135344b), C A. Grady, G Schneider, M L. Sitko, G M. Williger, K Hamaguchi, Sean D. Brittain, K Ablordeppey, D Apai, L Beerman, W J. Carpenter Jul 2009

Revealing The Structure Of A Pre-Transitional Disk: The Case Of The Herbig F Star Sao 206462 (Hd 135344b), C A. Grady, G Schneider, M L. Sitko, G M. Williger, K Hamaguchi, Sean D. Brittain, K Ablordeppey, D Apai, L Beerman, W J. Carpenter

Publications

SAO 206462 (HD 135344B) has previously been identified as a Herbig F star with a circumstellar disk with a dip in its infrared excess near 10 mum. In combination with a low accretion rate estimated from Br gamma, it may represent a gapped, but otherwise primordial or "pre-transitional" disk. We test this hypothesis with Hubble Space Telescope coronagraphic imagery, FUV spectroscopy and imagery and archival X-ray data, and spectral energy distribution (SED) modeling constrained by the observed system inclination, disk outer radius, and outer disk radial surface brightness (SB) profile using the Whitney Monte Carlo Radiative Transfer Code. The essentially …

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Overexpression Of A Mutant Form Of Ehraba, A Unique Rab Gtpase Of Entamoeba Histolytica, Alters Endoplasmic Reticulum Morphology And Localization Of The Gal/Galnac Adherence Lectin, B. H. Welter, Lesly A. Temesvari Jul 2009

Overexpression Of A Mutant Form Of Ehraba, A Unique Rab Gtpase Of Entamoeba Histolytica, Alters Endoplasmic Reticulum Morphology And Localization Of The Gal/Galnac Adherence Lectin, B. H. Welter, Lesly A. Temesvari

Publications

Entamoeba histolytica is a protozoan parasite that causes amoebic dysentery and liver abscess. Vesicle trafficking events, such as phagocytosis and delivery of plasma membrane proteins, have been implicated in pathogenicity. Rab GTPases are proteins whose primary function is to regulate vesicle trafficking; therefore, understanding the function of Rabs in this organism may provide insight into virulence. E. histolytica possesses a number of unique Rabs that exhibit limited homology to host Rabs. In this study we examined the function of one such Rab, EhRabA, by characterizing a mutant overexpressing a constitutively GTP-bound version of the protein. Overexpression of mutant EhRabA resulted …

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Consistency Of Developmental Outcomes Of 4-H Camp Experiences Over Time And Across Sites, Sarah Baughman, Barry A. Garst, Nicholas Fuhrman Jul 2009

Consistency Of Developmental Outcomes Of 4-H Camp Experiences Over Time And Across Sites, Sarah Baughman, Barry A. Garst, Nicholas Fuhrman

Publications

The purpose of this study was to explore the developmental outcomes of 4-H camp experiences as identified by parents and guardians. The authors examined (1) the changes in youth life skill behaviors that parents/guardians attribute to a 5-day residential 4-H camping experience, (2) their perceptions of consistency in the life skills gained across multiple camps and years, and (3) differences in life skill development between male and female youth participants. Parents of campers ages 9-13 were randomly sampled in 2001 (n=363), 2004 (n=326), and 2007 (n=326) and asked to report changes in their child's behavior following camp. Results indicate an …

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Influence Of Grow-Out Feed Fatty Acid Composition On Finishing Success In Nile Tilapia, Jesse T. Trushenski, John Boesenberg, Christopher C. Kohler Jul 2009

Influence Of Grow-Out Feed Fatty Acid Composition On Finishing Success In Nile Tilapia, Jesse T. Trushenski, John Boesenberg, Christopher C. Kohler

Publications

The fatty acid (FA) composition of cultured finfish can be tailored by transitioning fish reared on alternative lipid-based, low long-chain polyunsaturated FA (LC-PUFA) content grow-out feeds to high LC-PUFA finishing feeds based on fish oil (FO) before harvest. To determine whether the FA composition of the grow-out feed influences finishing success in Nile tilapia Oreochromis niloticus, coconut (CO), grapeseed (GO), linseed (LO), and poultry (PO) oils were evaluated in grow-out feeds with respect to production performance and responsiveness to finishing. The production performance of Nile tilapia was unaffected by application of the various feeding regimes, indicating that this species …

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A Near-Infrared Spectroscopic Survey Of Cool White Dwarfs In The Sloan Digital Sky Survey, Mukremin Kilic, Piotr M. Kowalski, Ted Von Hippel Jul 2009

A Near-Infrared Spectroscopic Survey Of Cool White Dwarfs In The Sloan Digital Sky Survey, Mukremin Kilic, Piotr M. Kowalski, Ted Von Hippel

Publications

We present near-infrared photometric observations of 15 and spectroscopic observations of 38 cool white dwarfs (WDs). This is the largest near-infrared spectroscopic survey of cool WDs to date. Combining the Sloan Digital Sky Survey photometry and our near-infrared data, we perform a detailed model atmosphere analysis. The spectral energy distributions of our objects are explained fairly well by model atmospheres with temperatures ranging from 6300 K down to 4200 K. Two WDs show significant absorption in the infrared, and are best explained with mixed H/He atmosphere models. Based on the up-to-date model atmosphere calculations by Kowalski & Saumon, we find …

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Preface: Proceedings Of The 13th International Symposium On Trichoptera, John Morse, Katarzyna Majecka, Janusz Majecki Jun 2009

Preface: Proceedings Of The 13th International Symposium On Trichoptera, John Morse, Katarzyna Majecka, Janusz Majecki

Publications

The 13th International Symposium on Trichoptera took place in Bialowieża, Poland, in 22-27 June 2009, but the idea to organize the symposium there was evoked 3 years earlier. When, at the end of the symposium in Mexico City, Professor Hans Malicky suggested that the next symposium take place in Poland, the first question we asked ourselves was, “Where could we organize it?” That night we were discussing this issue with several colleagues and Wolfram Mey said, “Why not do it in Białowieża?” The idea was tempting. In the last 2 decades Trichoptera symposia were organized in big cities. The last …

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Enhancing Research And Practice In Early Childhood Through Formative And Design Experiments, Barbara A. Bradley, David Reinking Jun 2009

Enhancing Research And Practice In Early Childhood Through Formative And Design Experiments, Barbara A. Bradley, David Reinking

Publications

This article describes formative and design experiments and how they can advance research and instructional practices in early childhood education. We argue that this relatively new approach to education research closes the gap between research and practice, and it addresses limitations that have been identified in early childhood research. We provide examples of this approach's potential benefits, trace its origins, present its defining characteristics, illustrate a representative framework for conducting a formative experiment using an example from our own work and we argue that formative and design experiments introduce useful new metaphors into early childhood research.

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The Trichoptera World Checklist, John C. Morse Jun 2009

The Trichoptera World Checklist, John C. Morse

Publications

The Trichoptera World Checklist (TWC) is a project of the successive International Symposia on Trichoptera, with the responsibility for its policy and maintenance assigned to the international Trichoptera Checklist Coordinating
Committee. The TWC originated 20 years ago and has been available on the worldwide web for over 11 years, providing ready access to data regarding caddisfly taxa. Security is assured by daily backup of the database. Trichoptera scientists everywhere are urged to continue sending their published research to the Editor. As of June 2009, the TWC included records for 13,574 valid, extant species and 308 valid, extant subspecies in 609 …

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The First Two Transient Supersoft X-Ray Sources In M31 Globular Clusters And The Connection To Classical Novae, M. Henze, W. Pietsch, F. Haberl, G. Sala, R. Quimby, M. Hernanz, M. Della Valle, P. Milne, G. G. Williams, V Burwitz, J Greiner, H Stiele, Dieter H. Hartmann, A.K.H. Dong, K Hornoch Jun 2009

The First Two Transient Supersoft X-Ray Sources In M31 Globular Clusters And The Connection To Classical Novae, M. Henze, W. Pietsch, F. Haberl, G. Sala, R. Quimby, M. Hernanz, M. Della Valle, P. Milne, G. G. Williams, V Burwitz, J Greiner, H Stiele, Dieter H. Hartmann, A.K.H. Dong, K Hornoch

Publications

Context. Classical novae (CNe) have been found to represent the major class of supersoft X-ray sources (SSSs) in our neighbour galaxy M 31. Aims. We determine the properties and evolution of the two first SSSs ever discovered in the M 31 globular cluster (GC) system. Methods. We have used XMM-Newton, Chandra and Swift observations of the centre region of M 31 to discover both SSSs and to determine their X-ray light curves and spectra. We performed detailed analysis of XMM-Newton EPIC PN spectra of the source in Bol 111 (SS1) using blackbody and NLTE white dwarf (WD) atmosphere models. For …

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Maturation And Reproduction Of Shovelnose Sturgeon In The Middle Mississippi River, Sara J. Tripp, Quinton E. Phelps, Robert E. Colombo, James E. Garvey, Brooks M. Burr, David P. Herzog, Robert A. Hrabik Jun 2009

Maturation And Reproduction Of Shovelnose Sturgeon In The Middle Mississippi River, Sara J. Tripp, Quinton E. Phelps, Robert E. Colombo, James E. Garvey, Brooks M. Burr, David P. Herzog, Robert A. Hrabik

Publications

Shovelnose sturgeon Scaphirhynchus platorynchus in the middle Mississippi River provide one of the last commercially viable sturgeon fisheries in the world, yet their maturation and reproduction have not been linked. During 2005 and 2006, we sampled adult and age-0 shovelnose sturgeon to link age at maturation, the timing and periodicity of spawning, age-0 sturgeon production, and the resulting age-0 growth rates. Age at maturity was later than previous estimates, the minimum age of first maturation being 8 years for males and 9 years for females. Total egg count was slightly lower than previously reported (mean = 29,573 per female; SE …

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Dredging And Dredged Material Beneficial Use In Ireland, Colm Sheehan, Joseph R. Harrington, Jerry Murphy Jun 2009

Dredging And Dredged Material Beneficial Use In Ireland, Colm Sheehan, Joseph R. Harrington, Jerry Murphy

Publications

This article provides an overview of the dredging industry in Ireland which may be small by international standards but is of critical importance to the nation’s Ports and Harbours. Open sea disposal of dredged material is most common, but a range of beneficial uses for the coarser fraction of dredged material has been practiced. Details on different aspects of dredging in Ireland are presented including a review of current beneficial uses. A specific site at Fenit Harbour in Tralee Bay is examined to assess the potential for a specific beneficial use of dredged material using geotubes in breakwater and revetment …

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Periodic And Chaotic Traveling Wave Patterns In Reaction-Diffusion/Predator-Prey Models With General Nonlinearities, S.C. Mancas, Roy S. Choudhury Jun 2009

Periodic And Chaotic Traveling Wave Patterns In Reaction-Diffusion/Predator-Prey Models With General Nonlinearities, S.C. Mancas, Roy S. Choudhury

Publications

Traveling wavetrains in generalized two–species predator–prey models and two–component reaction–diffusion equations are considered. The stability of the fixed points of the traveling wave ODEs (in the usual ”spatial” variable) is considered. For general functional forms of the nonlinear prey birthrate/prey deathrate or reaction terms, a Hopf bifurcation is shown to occur at two different critical values of the traveling wave speed. The post–bifurcation dynamics is investigated for five different functional forms of the nonlinearities. In cases where the bifurcation is supercritical, the post– bifurcation behaviour yields stable periodic orbits of the traveling–wave ODEs in the spatial variable. These correspond to …

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