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Full-Text Articles in Physical Sciences and Mathematics

Minerva 2007, The Honors College Dec 2007

Minerva 2007, The Honors College

Minerva

This issue of Minerva includes an article on the hiring of first-ever full-time Honors faculty members, Mimi Killinger and Mark Haggerty; an article on Honors alumna Molly Barker '00; and a reflection by former Honors Program Director Sam Schuman.


Effects Of An Inserted Endoscope On Chyme Movement In Small Intestine – A Theoretical Model, V. P. Srivastava Dec 2007

Effects Of An Inserted Endoscope On Chyme Movement In Small Intestine – A Theoretical Model, V. P. Srivastava

Applications and Applied Mathematics: An International Journal (AAM)

The effects of an inserted endoscope on chyme movement in small intestine (gastrointestinal tract) have been investigated. The flow of chyme is induced by a progressive wave of area contraction along the length of intestinal wall under long wavelength approximation. It is found that the chyme movement is significantly influenced due to the presence of the endoscope. The pressure drop assumes lower values for higher values of the endoscope radius for small flow rates but the property reverses with increasing flow rates. The friction forces at intestinal wall and endoscope possess character similar to the pressure drop for any given …


Age-Structured Population Model With Cannibalism, Mmohammed El-Doma Dec 2007

Age-Structured Population Model With Cannibalism, Mmohammed El-Doma

Applications and Applied Mathematics: An International Journal (AAM)

An age-structured population model with cannibalism is investigated. We determine the steady states and study the local asymptotic stability as well as the global stability. The results in this paper generalize previous results.


Stability Analysis For The Gurtin-Maccamy’S Age-Structured Population Dynamics Model, Mohammed El-Doma Dec 2007

Stability Analysis For The Gurtin-Maccamy’S Age-Structured Population Dynamics Model, Mohammed El-Doma

Applications and Applied Mathematics: An International Journal (AAM)

The stability of the Gurtin-MacCamy’s age-structured population dynamics model is investigated. We determine the steady states and study their stability. The results in this paper generalize previous results.


Virginia Junior Academy Of Science Awards, 2007 Jul 2007

Virginia Junior Academy Of Science Awards, 2007

Virginia Journal of Science

Virginia Junior Academy of Science Awards Presented During the 66th Annual Meeting at James Madison University, Harrisonburg, Virginia, May 23-25, 2007.


2007 Vas Meeting Best Student Papers Jul 2007

2007 Vas Meeting Best Student Papers

Virginia Journal of Science

List of award winning student papers by section from the 85th Annual Meeting of the Virginia Academy of Science, May 24-26, 2007, James Madison University, Harrisonburg, VA


Abstracts Of Papers, 85th Annual Meeting Of The Virginia Academy Of Science, May 24-26, 2007, James Madison University, Harrisonburg Va Jul 2007

Abstracts Of Papers, 85th Annual Meeting Of The Virginia Academy Of Science, May 24-26, 2007, James Madison University, Harrisonburg Va

Virginia Journal of Science

Full abstracts of the 85th Annual Meeting of the Virginia Academy of Science, May 24-26, 2007, James Madison University, Harrisonburg VA


Climate. A Period Of Consequence: Environmental Literature Of 2006, Shaun O'Connell Jul 2007

Climate. A Period Of Consequence: Environmental Literature Of 2006, Shaun O'Connell

New England Journal of Public Policy

The author talks about the consequences of not respecting the climate and understanding global warming will cause ecocide and our own extinction.


A Theoretical Model For Blood Flow In Small Vessels, V. P. Srivastava Jun 2007

A Theoretical Model For Blood Flow In Small Vessels, V. P. Srivastava

Applications and Applied Mathematics: An International Journal (AAM)

A two-fluid model consisting of a core region of suspension of all the erythrocytes (particles) in plasma (fluid) assumed to be a particle-fluid mixture and a peripheral layer of cell-free plasma (Newtonian fluid), has been proposed to represent blood flow in small diameter tubes. The analytical results obtained in the proposed model for effective viscosity, velocity profiles and flow rate have been evaluated numerically for various values of the parameters available from published works. Quantitative comparison has shown that present model suitability represents blood flow at hematocrit (less than or equal to 40%) and in vessels up to 70 micrometers …


An Age-Structured Resource-Consumer Dynamical Model, Jean M. Tchuenche Jun 2007

An Age-Structured Resource-Consumer Dynamical Model, Jean M. Tchuenche

Applications and Applied Mathematics: An International Journal (AAM)

Many dynamical systems in population biology in which agents compete for resources may exhibit chaotic fluctuations. This short letter develops Gamarra and Solé's previous work. We briefly review a classical model of population with complex dynamics, and proceed to study the dynamics of an age-structured resource-consumer model, in which the fertility coefficients are density independent. Implicit or first integral solutions of the model are obtained, and conditions for which they are stable given. It is observed that resource availability at any time depends on the number of potential consumers present.


Jeffress Research Grant - 2005 Apr 2007

Jeffress Research Grant - 2005

Virginia Journal of Science

Seven-page list of winners of the Jeffress Research Grant Awards for 2005.


Jeffress Research Grant Awards - 2006 Apr 2007

Jeffress Research Grant Awards - 2006

Virginia Journal of Science

List of winners of the Jeffress Research Grant Awards for 2006.


The Journal Of Undergraduate Research: Volume 05 Jan 2007

The Journal Of Undergraduate Research: Volume 05

The Journal of Undergraduate Research

This is the complete issue of the South Dakota State University Journal of Undergraduate Research, Volume 5.


Comparison Of Aquatic-Insect Habitat And Diversity Above And Below Road Crossings In Low-Order Streams, J. Wesley Neal, Nathan J. Harris, Sathyanand Kumaran, David A. Behler, Thomas J. Lang, Paul R. Port, Marcella Melandri, Benjamin G. Batten Jan 2007

Comparison Of Aquatic-Insect Habitat And Diversity Above And Below Road Crossings In Low-Order Streams, J. Wesley Neal, Nathan J. Harris, Sathyanand Kumaran, David A. Behler, Thomas J. Lang, Paul R. Port, Marcella Melandri, Benjamin G. Batten

Journal of the Arkansas Academy of Science

The effects of road crossings on fish communities have been extensively studied; yet little attention has been given to macroinvertebrate communities. This study evaluated physical stream characteristics, water quality, and aquatic-insect richness from above and below road crossings of low-order streams in the Ouachita National Forest in Arkansas. Fifteen road crossings were sampled during October and November 2005. Erosion was significantly higher below road crossings than above. Sites downstream of road crossings had significantly lower pH and significantly higher turbidity than sites upstream of road crossings. Despite differences in water quality and habitat, there was no apparent difference in aquatic-insect …


Schweinitz’S Sunflower Helianthus Schweinitzii Torrey And Gray, (Asterales: Asteraceae) In Upper Piedmont South Carolina, Steven E. Fields Jan 2007

Schweinitz’S Sunflower Helianthus Schweinitzii Torrey And Gray, (Asterales: Asteraceae) In Upper Piedmont South Carolina, Steven E. Fields

Journal of the South Carolina Academy of Science

No abstract provided.


The Effects Of 17Β-Estradiol And Tamoxifen On Cell Cycle Distribution And F-Actin Expression In Mcf-7 Cells, Kirk Kangaloo, Latoya Jenkins, Nicole Clarke, Samir S. Raychoudhury Jan 2007

The Effects Of 17Β-Estradiol And Tamoxifen On Cell Cycle Distribution And F-Actin Expression In Mcf-7 Cells, Kirk Kangaloo, Latoya Jenkins, Nicole Clarke, Samir S. Raychoudhury

Journal of the South Carolina Academy of Science

No abstract provided.


Weather Factors Influencing Winter Roosts Of American Crows In Central Iowa, Joshua D. Obrecht, Stephen J. Dinsmore Jan 2007

Weather Factors Influencing Winter Roosts Of American Crows In Central Iowa, Joshua D. Obrecht, Stephen J. Dinsmore

Journal of the Iowa Academy of Science: JIAS

We investigated the effects of season and weather on the winter roosting behavior of American Crows (Corvus brachyrhynchos) in central Iowa from January through March 2006. The peak number of birds recorded at a roost in Ames, Story County was 9,000+ in early February, and the number of individuals entering the roost decreased through February and March. Crows tended to enter the roost later in the day as winter neared completion. High wind speed and low light intensity caused individual to enter the roost earlier in the day. Temperature did not affect arrival time of crows. Wind speed, light intensity, …


Forging A Common Vision For Maine’S North Woods, Robert J. Lilieholm Jan 2007

Forging A Common Vision For Maine’S North Woods, Robert J. Lilieholm

Maine Policy Review

Robert Lilieholm takes stock of the challenges and opportunities facing Maine’s North Woods, the largest undeveloped forested block in the eastern United States. In the face of changing ownership patterns and development pressures, there is lively debate over current land use policies and trends. Lilieholm suggests that a broader, regional vision for the North Woods might better serve the long-term interests of both the area’s forests and its struggling communities.


Editorial Board & Iowa Academy Of Science Officers And Directors Jan 2007

Editorial Board & Iowa Academy Of Science Officers And Directors

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Back Cover Jan 2007

Back Cover

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Cover - Table Of Contents Jan 2007

Cover - Table Of Contents

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


An Inventory Of The Vascular Flora Of Hamilton County, Iowa (2001-2004), Jimmie D. Thompson Jan 2007

An Inventory Of The Vascular Flora Of Hamilton County, Iowa (2001-2004), Jimmie D. Thompson

Journal of the Iowa Academy of Science: JIAS

A botanical survey of the vascular flora of Hamilton County, Iowa was conducted from 2001 to 2004. During this survey 973 taxa (761 native) were encountered. A search of the literature and a survey of Iowa State University's Ada Hayden Herbarium for additional documented specimens added 28 taxa to the flora. This total of 1001 taxa places Hamilton County fourth in vascular plant richness among inventories conducted in Iowa since 1950. A checklist including common names of most taxa, habitat and abundance data for all taxa encountered during the current survey is presented. Information on earlier collections includes source and …


Front Matter Jan 2007

Front Matter

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Narrow Sense Heritability And Additive Genetic Correlations In Alfalfa Subsp. Falcata, Heathcliffe Riday, E. Charles Brummer Jan 2007

Narrow Sense Heritability And Additive Genetic Correlations In Alfalfa Subsp. Falcata, Heathcliffe Riday, E. Charles Brummer

Journal of the Iowa Academy of Science: JIAS

The complex genetics of autotetraploid alfalfa (Medicago sativa L.) make additive genetic variance component estimation difficult. Halfsib family variances often are used to estimate additive genetic variances and, by extension, narrow sense heritabilities and additive genetic correlations. These estimates contain a portion of the dominance variance. Using such calculations, in conjunction with parent-offspring covariance estimates, the dominance component can be separated from the additive genetic component. This is rarely done. This study reports average estimates across 30 populations, of both additive and dominance variance component estimates based on between halfsib family variance and parent-offspring covariance for biomass yield, plant height, …


Fall And Winter Food Habits Of Bobcats (Lynx Rufus) In Iowa, Kelcey J. Brockmeyer, William R. Clark Jan 2007

Fall And Winter Food Habits Of Bobcats (Lynx Rufus) In Iowa, Kelcey J. Brockmeyer, William R. Clark

Journal of the Iowa Academy of Science: JIAS

The bobcat (Lynx rufus) is a widely distributed native felid of North America but nearly disappeared from Iowa due to habitat loss and unregulated harvest that occurred during the century after European settlement. Bobcats are repopulating the state and are now relatively common in southern Iowa. This study was part of a research project to understand the ecology of the species in Iowa's landscape so that conservation plans could be established. We determined food habits by the examination of stomach contents from 100 bobcat carcasses that were accidentally killed in traps, killed by automobiles, or radio-marked individuals found dead during …


Laboratory Abrasion Of Crinoid Columnals And The Provenance Of The Chariton Conglomerate, South-Central Iowa, Justin C. Kraber, Steven H. Emerman, Matt R. Bennett, Lyndon R. Hawkins, Jewell E. Moore, Rebekah Ellenwood, Kristine L. Robson, Adam Finken Jan 2007

Laboratory Abrasion Of Crinoid Columnals And The Provenance Of The Chariton Conglomerate, South-Central Iowa, Justin C. Kraber, Steven H. Emerman, Matt R. Bennett, Lyndon R. Hawkins, Jewell E. Moore, Rebekah Ellenwood, Kristine L. Robson, Adam Finken

Journal of the Iowa Academy of Science: JIAS

The Chariton Conglomerate is a quartz limestone conglomerate of Pennsylvanian age found in six exposures in southern Iowa and three exposures in northern Missouri. Distinctive features of the exposures in Iowa include quartz granules and rounded crinoid columnals. The objective of this study was to determine whether the quartz clasts could have originated in the crystalline rocks of Minnesota or Wisconsin. The average paleocurrent direction measured in interbedded sandstones was 178° (S.D. = 35 °). The average roundness of 75 crinoid columnals extracted from four exposures in Iowa was 30% (S.D. = 14%), defined as

roundness(%) = (D-d)/D x 100, …


Are The Economics Of A Sustainable Maine Forest Sustainable?, Mike Levert, Charles S. Colgan, Charles Lawton Jan 2007

Are The Economics Of A Sustainable Maine Forest Sustainable?, Mike Levert, Charles S. Colgan, Charles Lawton

Maine Policy Review

Mike LeVert, Charles Colgan and Charles Lawton discuss the transformation of the economic environment of Maine’s forests over the past two decades. Paper companies have sold most of their holdings; residential and conservation demand for land has increased; forestland prices have skyrocketed; and new classes of landowners have different strategies, objectives, and time horizons than the old industrial landowners. The authors believe that management of Maine’s forests must now address changes in the economic environment with the same intensity as threats such as the spruce budworm were addressed if we are to keep Maine’s forests as forests.


Using Microenvironmental Effects: Loading, Activity, And Stereoselectivity Relative To Polymer Bound Nabh4 Reagents, James R. Blanton Jan 2007

Using Microenvironmental Effects: Loading, Activity, And Stereoselectivity Relative To Polymer Bound Nabh4 Reagents, James R. Blanton

Journal of the South Carolina Academy of Science

No abstract provided.