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Full-Text Articles in Life Sciences

Manipulation Of Prenatal Hormones And Dietary Phytoestrogens During Adulthood Alter The Sexually Dimorphic Expression Of Visual Spatial Memory, Edwin D. Lephart, Trent D. Lund Dec 2001

Manipulation Of Prenatal Hormones And Dietary Phytoestrogens During Adulthood Alter The Sexually Dimorphic Expression Of Visual Spatial Memory, Edwin D. Lephart, Trent D. Lund

Faculty Publications

In learning and memory tasks, requiring visual spatial memory (VSM), males exhibit higher performance levels compared to females (a difference attributed to sex steroid hormonal influences). Based upon the results from our companion investigation, this study examined the influence of prenatal sex steroid hormone manipulations on VSM in adulthood, as assessed in the radial arm maze. Additionally, the influence of dietary soy phytoestrogens (i.e., the presence of high or low estrogen-like compounds present in the animal's diet) on VSM was examined in combination with the prenatal hormonal manipulations. Results: Radial arm maze performance on a phytoestrogen-rich diet: 1 ...


Visual Spatial Memory Is Enhanced In Female Rats (But Inhibited In Males) By Dietary Soy Phytoestrogens, Edwin D. Lephart, Trent D. Lund, Timothy W. West, Lilyan Y. Tian, Lihong H. Bu, Daniel L. Simmons, Kenneth Setchell, Herman Adlercreutz Dec 2001

Visual Spatial Memory Is Enhanced In Female Rats (But Inhibited In Males) By Dietary Soy Phytoestrogens, Edwin D. Lephart, Trent D. Lund, Timothy W. West, Lilyan Y. Tian, Lihong H. Bu, Daniel L. Simmons, Kenneth Setchell, Herman Adlercreutz

Faculty Publications

In learning and memory tasks, requiring visual spatial memory (VSM), males exhibit superior performance to females (a difference attributed to the hormonal influence of estrogen). This study examined the influence of phytoestrogens (estrogen-like plant compounds) on VSM, utilizing radial arm-maze methods to examine varying aspects of memory. Additionally, brain phytoestrogen, calbindin (CALB), and cyclooxygenase-2 (COX-2) levels were determined. Results: Female rats receiving lifelong exposure to a high-phytoestrogen containing diet (Phyto-600) acquired the maze faster than females fed a phytoestrogen-free diet (Phyto-free); in males the opposite diet effect was identified. In a separate experiment, at 80 days-of-age, animals fed the Phyto-600 ...


Microscale Patchiness Of Bacterioplankton Assemblage Richness In Seawater, Richard A. Long, Farooq Azam Dec 2001

Microscale Patchiness Of Bacterioplankton Assemblage Richness In Seawater, Richard A. Long, Farooq Azam

Faculty Publications

We sought to test the hypothesis that bacterial species richness and composition vary at the millimeter scale in the marine pelagic environment, in response to the heterogeneous distribution of organic matter. To test this hypothesis, it was necessary to design and test a protocol to sample, lyse and analyze (by polymerase chain reaction/denaturing gradient gel electrophoresis [PCR-DGGE]) bacterioplankton species richness in a single microliter of seawater. Significant variation in bacterial species richness was found amongst 1 μl samples. Greater species richness was seen when seawater was enriched with diatom detritus. Examination of species richness at 2 mm intervals over ...


Host-Switching Does Not Circumvent The Ni-Based Defence Of The Ni Hyperaccumulator Streptanthus Polygaloides (Brassicaceae), Micheal A. Davis, Robert S. Boyd, James H. Cane Nov 2001

Host-Switching Does Not Circumvent The Ni-Based Defence Of The Ni Hyperaccumulator Streptanthus Polygaloides (Brassicaceae), Micheal A. Davis, Robert S. Boyd, James H. Cane

Faculty Publications

Elevated tissue concentrations of metals have been shown to defend metal-hyperaccumulating plants against both herbivores and pathogens. Tolerance of metal-based defences presents a challenge to herbivores, because heavy metals cannot be degraded or metabolized. One strategy that herbivores can employ to counter high-metal defences is dietary dilution, or host switching. Highly mobile herbivores are most likely to use this strategy, but less mobile lepidopteran larvae can also Improve their performance on toxic hosts if early instar development occurs on more favourable hosts. We examined the effects of host switching on growth and survival of a generalist folivore. Specifically, we tested ...


Pfiesteria: Review Of The Science And Identification Of Research Gaps. Report For The National Center For Environmental Health, Centers For Disease Control And Prevention, Jonathan Samet, Gary S. Bignami, Robert Feldman, William E. Hawkins, Jerry Neff, Theodore Smayda Oct 2001

Pfiesteria: Review Of The Science And Identification Of Research Gaps. Report For The National Center For Environmental Health, Centers For Disease Control And Prevention, Jonathan Samet, Gary S. Bignami, Robert Feldman, William E. Hawkins, Jerry Neff, Theodore Smayda

Faculty Publications

In connection with the CDC National Conference on Pfiesteria, a multidisciplinary panel evaluated Pfiesteria-related research. The panel set out what was known and what was not known about adverse effects of the organism on estuarine ecology, fish, and human, health; assessed the methods used in Pfiesteria research; and offered suggestions to address data gaps. The panel's expertise covered dinoflagellate ecology; fish pathology and toxicology; laboratory measurement of toxins, epidemiology, and neurology. The panel evaluated peer-reviewed and non-peer-reviewed literature available through June 2000 in a systematic conceptual framework that moved from the source of exposure, through exposure research and dose ...


Effects Of River Inputs Into The Bay Of Bengal, Stephan D. Howden, Raghu Murtugudde Sep 2001

Effects Of River Inputs Into The Bay Of Bengal, Stephan D. Howden, Raghu Murtugudde

Faculty Publications

The effect of river runoff in the Bay of Bengal is examined using a reduced gravity primitive equation ocean model coupled to an atmospheric boundary layer model. Model simulations are carried out by including river discharges as surface freshwater forcing at the mouths of the rivers. To assess the effect of river inputs on the dynamics and thermodynamics of the tropical Indian Ocean, parallel simulations are carried out by neglecting the river inputs. Additionally, another set of parallel runs without penetrative radiation loss through the mixed layer is carried out. The freshwater flux due to rivers results in lower salinities ...


Experimental Evaluation Of Vitellogenin As A Predictive Biomarker For Reproductive Disruption, Ann Oliver Cheek, Thea Hoexum Brouwer, Suzanne Carroll, Steve Manning, John A. Mclachlan, Marius Brouwer Jul 2001

Experimental Evaluation Of Vitellogenin As A Predictive Biomarker For Reproductive Disruption, Ann Oliver Cheek, Thea Hoexum Brouwer, Suzanne Carroll, Steve Manning, John A. Mclachlan, Marius Brouwer

Faculty Publications

Vitellogenin (VTG) synthesis in male oviparous vertebrates is used as an indicator of environmental estrogen exposure, but the relationship between elevated VTG levels and the effects of environmental estrogens on reproductive success are poorly understood. To examine whether altered VTG expression predicts reproductive impairment, we exposed medaka (Oryzias latipes) for 2 or 8 weeks posthatch to 0, 0.5, 1.0, 2.5, and 7.5 ppb of the environmental estrogen o,p ' -DDT. Fish were sampled 2, 4, and 8 weeks after hatch to examine VTG expression and gonad development. After exposure, fish were transferred to clean water, grown ...


Shape Imprinting Due To Variable Disulfide Bonds In Polyacrylamide Gels, Andrew B. Greytak, Alexander Y. Grosberg, Toyoichi Tanaka Jun 2001

Shape Imprinting Due To Variable Disulfide Bonds In Polyacrylamide Gels, Andrew B. Greytak, Alexander Y. Grosberg, Toyoichi Tanaka

Faculty Publications

Through the use of variable disulfide crosslinkers, we have created polyacrylamide gels whose shape can be altered after polymerization. N,N'-bisacryloylcystamine is incorporated as a crosslinker, along with a smaller amount of a permanent crosslinker. After polymerization, the disulfide bonds are cleaved into thiols through reduction. By reoxidizing the thiols with the gel held in a new macroscopic shape, a new set of disulfide bonds is formed, and the gel is forced to adopt the new shape. Retension of the new shape improves with greater distortion from the original shape, as well as with increased concentration of variable disulfide ...


Chloropigment Distribution And Transport On The Inner Shelf Off Duck, North Carolina, Eurico J. D'Sa, Steven E. Lohrenz, James H. Churchill, Vernon L. Asper, John L. Largier, Albert J. Williams Iii Jun 2001

Chloropigment Distribution And Transport On The Inner Shelf Off Duck, North Carolina, Eurico J. D'Sa, Steven E. Lohrenz, James H. Churchill, Vernon L. Asper, John L. Largier, Albert J. Williams Iii

Faculty Publications

The distribution and movement of chloropigments (chlorophylls and associated degradation products) in the bottom boundary layer near Duck, North Carolina, were examined during July and August 1994. Time series of chloropigment fluorescence, current velocity, and surface wave properties were acquired from instruments mounted on a bottom tripod set at 20 m depth. These data were combined with moored current meter measurements, meteorological data, and shipboard surveys in a comparative assessment of physical processes and chloropigment distribution over a wide range of temporal and spatial scales. Two dominant scales of chloropigment variation were observed. On numerous occasions, small-scale (order m) structure ...


Comparative Phylogeography Of Mesoamerican Highland Rodents: Concerted Versus Independent Response To Past Climatic Fluctuations, Duke S. Rogers, Jack Sullivan, Elizabeth Arellano Jun 2001

Comparative Phylogeography Of Mesoamerican Highland Rodents: Concerted Versus Independent Response To Past Climatic Fluctuations, Duke S. Rogers, Jack Sullivan, Elizabeth Arellano

Faculty Publications

The phylogeography of Sumichrast's harvest mouse (Reithrodontomys sumichrasti) was examined through maximumlikelihood and parsimony analyses of 1,130 bp of mitochondrial Cytochrome b sequence data from 43 individuals. The phylogeography of this Middle American highland forest-dwelling species was compared to that previously published for the codistributed Aztec deer mouse complex (Peromyscus aztecus/Peromyscus hylocetes complex) in order to test competing hypotheses of concerted versus independent responses of codistributed forms to past climatic fluctuations. Qualitatively, there were strong similarities in the phylogeographic patterns of the two groups, yet there were also areas of incongruence. Likelihood-ratio tests (Kishino-Hasegawa-Templeton and parametric bootstrap ...


Molecular Diversity, Structure And Domestication Of Grasses, Edwards S. Buckler Iv, Jeffry M. Thornsberry, Stephen Kresovich Jun 2001

Molecular Diversity, Structure And Domestication Of Grasses, Edwards S. Buckler Iv, Jeffry M. Thornsberry, Stephen Kresovich

Faculty Publications

Over the last 10,000 years, crop domestication has been the single most important human cultural development. Grasses are prominent among these crops, and provide the vast majority of the world's food. Similar traits have been selected during the domestication and breeding of these critically important grasses, and since they share a similar complement of genes, the same set of genes may have been selected. Even though the process of domestication occurred over the same 5000 to 10,000 year period, the domesticated grasses have major differences in genome structure, diversity, and life history. Molecular investigations of grass domestication ...


How To Evaluate The Financial Maturity Of Timber, Steven H. Bullard Jun 2001

How To Evaluate The Financial Maturity Of Timber, Steven H. Bullard

Faculty Publications

If you own merchantable timber, you face an important question on a continuing basis: "Should I sell my timber now or should I wait?" How you respond to this question involves many issues, of course, including stand conditions, site conditions, and other physical and biological considerations. For many landowners, however, financial considerations are also extremely important. In this article we discuss "financial maturity" as a specific tool that can be used to help evaluate timber harvest decisions.


Seasonal Variation Of The North Atlantic Current, Max I. Yaremchuk, Dmitri A. Nechaev, Keith R. Thompson Apr 2001

Seasonal Variation Of The North Atlantic Current, Max I. Yaremchuk, Dmitri A. Nechaev, Keith R. Thompson

Faculty Publications

The seasonal circulation of the upper 1000 m of the North Atlantic between 40 degrees -55 degreesN and 20 degrees -40 degreesW is calculated using the traditional dynamic method and a circulation model with a density field that evolves with the flow. The model is of finite difference form and is based on dynamics that describe the nonlinear evolution of the ocean at low Rossby number. The model is controlled by initial and boundary conditions that include air-sea buoyancy and momentum fluxes. The model is run in two ways: with controls specified directly from observations and with controls inferred by ...


The Problem With Training-And-Visit Extension, Sarah Kimakwa Apr 2001

The Problem With Training-And-Visit Extension, Sarah Kimakwa

Faculty Publications

No abstract provided.


Variations In Bacterial Community Structure During A Dinoflagellate Bloom Analyzed By Dgge And 16s Rdna Sequencing, Laura B. Fandino, Lasse Riemann, Grieg F. Steward, Richard A. Long, Farooq Azam Jan 2001

Variations In Bacterial Community Structure During A Dinoflagellate Bloom Analyzed By Dgge And 16s Rdna Sequencing, Laura B. Fandino, Lasse Riemann, Grieg F. Steward, Richard A. Long, Farooq Azam

Faculty Publications

The relationship between bacterial 16S rRNA gene composition and carbon metabolism was analyzed during an intense dinoflagellate bloom off the Southern California coast during the spring of 1997. Bacterial numbers and rate processes, chlorophyll a, and the dissolved and particulate organic matter pools were measured during the bloom to provide a framework within which to assess bacterial community composition. Free bacteria were numerically dominant, generally comprising >90% of the total, and were responsible for >70% of bacterial production. Attached bacteria had higher cell-specific growth rates than free bacteria (range = 0.5 to 15.1 and 0.7 to 2.5 ...


Process For Immobilizing Waste Using Bagasse (Us Patent 6174275), Michael A. Janusa Jan 2001

Process For Immobilizing Waste Using Bagasse (Us Patent 6174275), Michael A. Janusa

Faculty Publications

No abstract provided.


Seed Security: How Far Has Pelum Come?, Sarah Kimakwa Jan 2001

Seed Security: How Far Has Pelum Come?, Sarah Kimakwa

Faculty Publications

No abstract provided.


Using Upper Boundary Constraints To Quantify Competitive Response Of Desert Annuals, Laura M. Lessin, Andrew R. Dyer, Deborah E. Goldberg Jan 2001

Using Upper Boundary Constraints To Quantify Competitive Response Of Desert Annuals, Laura M. Lessin, Andrew R. Dyer, Deborah E. Goldberg

Faculty Publications

Using a target-neighborhood approach with six annual dicot species in the Negev Desert of Israel, we tested whether neighborhood biomass constrained the upper limit of plant performance and if the slope of the upper boundary was correlated to species trait means, such as relative growth rate (RGR) and seed mass. Target individuals were measured in early spring and then collected at the onset of the dry season along with all naturally occurring neighbors within a 5-cm radius of the target. Using a minimum of 50 samples for each of the six target species, we found no significant relationships between target ...


A Comparison Of Methods To Evaluate Energy Expenditure Of Incubating Wandering Albatrosses, Scott A. Shaffer, D P. Costa, H Weimerskirch Jan 2001

A Comparison Of Methods To Evaluate Energy Expenditure Of Incubating Wandering Albatrosses, Scott A. Shaffer, D P. Costa, H Weimerskirch

Faculty Publications

Measurements of incubation energetics can vary depending on the method used to measure metabolism of an incubating bird. Therefore, we evaluated the energy expenditure of six male and four female wandering albatrosses (Diomedea exulans Linnaeus) using doubly labeled water (DLW), the rate of mass loss, and estimates of metabolic water production derived from water influx rate (WIR). Incubation metabolic rates (IMR) determined with DLW ( 169 ± 21 kJ kg d SD) were significantly lower than estimates derived from mass loss ( 277 ± 46kJ kg d SD) and WIR ( males=289 ± 60 kJ kg d vs. females = 400 ± 69 kJ kg d SD ...


Il-1Α And Tnf-Α Down-Regulate Crh Receptor-2 Mrna Expression In The Mouse Heart, Sarah C. Coste, Kurt A. Heldwein, Susan L. Stevens, Eric Tobar-Dupres, Mary P. Stenzel-Poore Jan 2001

Il-1Α And Tnf-Α Down-Regulate Crh Receptor-2 Mrna Expression In The Mouse Heart, Sarah C. Coste, Kurt A. Heldwein, Susan L. Stevens, Eric Tobar-Dupres, Mary P. Stenzel-Poore

Faculty Publications

Two receptors (CRH receptor type 1 and CRH receptor type 2) have been identified for the stress-induced neuropeptide, CRH and related peptides, urocortin, and urocortin II. We previously found marked down-regulation of cardiac CRH receptor type 2 expression following administration of bacterial endotoxin, lipopolysaccharide, a model of systemic immune activation, and inflammation. We postulated that inflammatory cytokines may regulate CRH receptor type 2. We show that systemic IL-1α administration significantly down-regulates CRH receptor type 2 mRNA in mouse heart. In addition, TNFα treatment also reduces CRH receptor type 2 mRNA expression, although the effect was not as marked as with ...


A Role For Actin, Cdc1p, And Myo2p In The Inheritance Of Late Golgi Elements In Saccharomyces Cerevisiae, Olivia W. Rossanese, Catherine A. Reinke, Brooke J. Bevis, Adam T. Hammond, Irina B. Sears, James O'Connor, Benjamin S. Glick Jan 2001

A Role For Actin, Cdc1p, And Myo2p In The Inheritance Of Late Golgi Elements In Saccharomyces Cerevisiae, Olivia W. Rossanese, Catherine A. Reinke, Brooke J. Bevis, Adam T. Hammond, Irina B. Sears, James O'Connor, Benjamin S. Glick

Faculty Publications

In Saccharomyces cerevisiae, Golgi elements are present in the bud very early in the cell cycle. We have analyzed this Golgi inheritance process using fluorescence microscopy and genetics. In rapidly growing cells, late Golgi elements show an actin-dependent concentration at sites of polarized growth. Late Golgi elements are apparently transported into the bud along actin cables and are also retained in the bud by a mechanism that may involve actin. A visual screen for mutants defective in the inheritance of late Golgi elements yielded multiple alleles of CDC1. Mutations in CDC1 severely depolarize the actin cytoskeleton, and these mutations prevent ...


Perspectives On Publication Among Highly Productive Women Adapted Physical Activity Scholars [Abstract], Deborah Buswell, Claudine Sherrill, Ron French, Bettye Myers Jan 2001

Perspectives On Publication Among Highly Productive Women Adapted Physical Activity Scholars [Abstract], Deborah Buswell, Claudine Sherrill, Ron French, Bettye Myers

Faculty Publications

No abstract provided.


Simulations Of Quasigeostrophic Currents Derived From Satellite Altimetry And Acoustic Tomography Of An Open Ocean Region, Max I. Yaremchuk, Dmitri A. Nechaev Jan 2001

Simulations Of Quasigeostrophic Currents Derived From Satellite Altimetry And Acoustic Tomography Of An Open Ocean Region, Max I. Yaremchuk, Dmitri A. Nechaev

Faculty Publications

Acoustic tomography (AT) and satellite altimetry (SA) measure properties of the ocean state with high temporal resolution. That makes these data suitable for long-term monitoring of mesoscale features in the open ocean regions, where the open boundaries are the major sources of model forecast uncertainties on timescales larger than 1 week. In this paper, a finite-difference quasigeostrophic model of an open ocean region is considered as a possible tool for interpolating AT-SA data in space and time. The assimilation algorithm is based upon the 4D variational data assimilation scheme controlled by the initial and boundary conditions of the model. The ...


Does Red-Cockaded Woodpecker Excavation Of Resin Wells Increase Risk Of Bark Beetle Infestation Of Cavity Trees?, Richard N. Conner, Daniel Saenz, D. Craig Rudolph, W. G. Ross, David Kulhavy, Robert Coulson Jan 2001

Does Red-Cockaded Woodpecker Excavation Of Resin Wells Increase Risk Of Bark Beetle Infestation Of Cavity Trees?, Richard N. Conner, Daniel Saenz, D. Craig Rudolph, W. G. Ross, David Kulhavy, Robert Coulson

Faculty Publications

No abstract provided.


Reproductive Biology Of Cobia, Rachycentron Canadum, From Coastal Waters Of The Southern United States, Nancy J. Brown-Peterson, Robin M. Overstreet, Jeffrey M. Lotz, James S. Franks, Karen M. Burns Jan 2001

Reproductive Biology Of Cobia, Rachycentron Canadum, From Coastal Waters Of The Southern United States, Nancy J. Brown-Peterson, Robin M. Overstreet, Jeffrey M. Lotz, James S. Franks, Karen M. Burns

Faculty Publications

Reproductive biology of the cobia, Rachycentron canadum, is described from four coastal areas in the southern United States. Samples were obtained from recreational fishermen between December 1995 and November 1997 from the southeastern United States (Morehead City, NC, to Cape Canaveral, FL), the eastern Gulf of Mexico (Ft. Myers to Crystal River, FL), the north-central Gulf of Mexico (Destin, FL, to Chandeleur Islands, LA) and the western Gulf of Mexico (Port Aransas, TX). Histological evidence of spawning occurred from April through September in all areas. Some female cobia (17-32%) throughout the Gulf of Mexico had spent or regressed ovaries by ...


Identifying A Damped Oscillatory Thermohaline Mode In A General Circulation Model Using An Adjoint Model, Ziv Sirkes, Eli Tziperman Jan 2001

Identifying A Damped Oscillatory Thermohaline Mode In A General Circulation Model Using An Adjoint Model, Ziv Sirkes, Eli Tziperman

Faculty Publications

A damped oscillatory mode of the thermohaline circulation (THC), which may play a role in interdecadal climate variability, is identified in a global primitive equation model. This analysis is done under mixed boundary conditions using an adjoint of the primitive equation model. The linearized versus nonlinear stability behavior of the model is studied by comparing the adjoint analysis to runs of the fully nonlinear model. It is shown that a steady-state solution obtained under larger amplitude freshwater surface forcing (and hence with a weaker North Atlantic overturning) is unstable, while a steady-state solution with stronger THC is stable. In a ...


Amaranthus Rudis And A. Tuberculatus, One Species Or Two? [Abstract], Donald B. Pratt, Lynn G. Clark Jan 2001

Amaranthus Rudis And A. Tuberculatus, One Species Or Two? [Abstract], Donald B. Pratt, Lynn G. Clark

Faculty Publications

No abstract provided.


Introduction To Forestry Investment Analysis: Part I. Basic Investment Characteristics And Financial Criteria, Thomas J. Straka, Steven H. Bullard, Mark R. Dubois Jan 2001

Introduction To Forestry Investment Analysis: Part I. Basic Investment Characteristics And Financial Criteria, Thomas J. Straka, Steven H. Bullard, Mark R. Dubois

Faculty Publications

Many forest landowners consider their forest to be an investment. Some of these landowners, however, and many new timberland investors, may not fully understand the basic ingredients that make up a forestry investment. Like all investments, forestry involves costs and revenues, and rates of return can be calculated. These rates of return can be compared with interest rates earned for other investments, but forest landowners should be sure to understand the unique characteristics of a forestry investment. Most of the cash flow from a forestry investment will result from timber sales. Timber sale revenue, of course, is a function of ...


Delayed Reproduction Of Translocated Red-Cockaded Woodpeckers., Brent Burt, James R. Mccormick, Richard N. Conner, Daniel Saenz Jan 2001

Delayed Reproduction Of Translocated Red-Cockaded Woodpeckers., Brent Burt, James R. Mccormick, Richard N. Conner, Daniel Saenz

Faculty Publications

Twelve pairs of Red-cockaded Woodpeckers were translocated to the Angelina National Forest. Five breeding pairs produced eggs/nestlings within the first breeding season after translocation. Clutch initiation dates for all five pairs were later than those of resident breeders. The observed delay in reporductive timing by translocated woodpeckers may have resulted from a variety of factors.


Forval-Online: A Web-Based Forestry Investment Tool, Clay B. Landrum, Steven H. Bullard Jan 2001

Forval-Online: A Web-Based Forestry Investment Tool, Clay B. Landrum, Steven H. Bullard

Faculty Publications

Over the past decade, timber values have risen considerably, and society is beginning to see timberland for what it is – a valuable capital asset that must be managed properly. Timberlands, however, cannot be subject to an “across the board” management regime. Different sites possess different productive constraints, and the same holds true for landowners and their management goals. Considering the diversity of managers’ and landowners’ analysis needs, the ability to obtain a customized forestry investment analysis is invaluable. “FORVAL-online: A Web-based Forestry Investment Tool” is a project to develop and make widely available an accurate and easy to use forestry ...