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2006

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Articles 331 - 360 of 536

Full-Text Articles in Biology

The Effect Of Prey Availability On Metabolism And Activity In The Tarantula Phormictopus Cancerides (Araneae: Theraphosidae), Benjamin Nathan Philip Jan 2006

The Effect Of Prey Availability On Metabolism And Activity In The Tarantula Phormictopus Cancerides (Araneae: Theraphosidae), Benjamin Nathan Philip

Master's Theses and Doctoral Dissertations

This study examined the effect of different periods of food deprivation on resting metabolic rates (RMR) and foraging activities in tarantulas (Phormictopus cancerides). Juvenile tarantulas were separated into two feeding groups and fed once either every 5 or 30 days. Monthly feeding trials were preceded by RMR measurements. During feeding trials I compared differences between the two groups in (1) prey capture rates, (2) time to prey capture, (3) locomotory activity, and (4) the predator’s prey detection distance. RMRs increased for the well-fed group but remained consistent for individuals, fed only once a month. Time to prey capture …


The Influence Of Woodlot Size And Location In Suburban And Rural Matrices On Bird Species Richness And Individual Abundance, Neil Allen Chartier Jan 2006

The Influence Of Woodlot Size And Location In Suburban And Rural Matrices On Bird Species Richness And Individual Abundance, Neil Allen Chartier

Master's Theses and Doctoral Dissertations

This study assessed the influence of woodlot area and matrix composition on bird species richness and individual abundance. Bird surveys were conducted in winter 2004 and 2005 and spring 2005. Woodlot area and landscape composition were analyzed using GIS software. In winter, resident species richness and abundance increased as landscape diversity increased, whereas in spring, resident species richness decreased with increased landscape openness and abundance increased as woodlot area increased. Spring migrant species richness increased with increased landscape openness, and abundance decreased as woodlot area increased. In winter, Tufted Titmice were more likely to be present in smaller woodlots, whereas …


Man-Made Menopause, Madeline Horwitz Jan 2006

Man-Made Menopause, Madeline Horwitz

Undergraduate Research Symposium (UGRS)

In this study I suggest that there are three distinct time periods mark new developments in society’s understanding of menopause, Victorian America in the mid and late nineteenth century, mid-twentieth century America, and contemporary America. This is the case not only in terms of advances in biological science, but also the ways in which the medical establishment has viewed menopause has also changed, and in terms of changes in prevalent gender assumptions. In this paper I hope to expose the ways science, history, and society has medicalized menopause, and the ways in which menopause has been viewed by individual women, …


Notopleural Mutations Enhance Defects In Imaginal Disc Epithelial Morphogenesis And Macrochete Elongation Associated With Mutations In The Stubble-Stubbloid Locus, Robert Ruggiero Jan 2006

Notopleural Mutations Enhance Defects In Imaginal Disc Epithelial Morphogenesis And Macrochete Elongation Associated With Mutations In The Stubble-Stubbloid Locus, Robert Ruggiero

Electronic Theses and Dissertations

The Stubble-stubbloid locus encodes a transmembrane serine protease (Stubble) necessary for the proper formation of sensory bristles, and the morphogenesis of leg and wing epithelia. Genetic and cell biological analysis indicate a role for Stubble in actin cytoskeletal dynamics and cell shape changes in developing epithelia and bristles. Previously reported genetic interactions between Stubble and the Rho1 signaling pathway suggest Stubble influences actin cytoskeleton dynamics in developing imaginal discs through interactions with the Rho1 pathway. This work will discuss a genetic screen conducted to further investigate the role of Stubble in bristle and imaginal disc morphogenesis. From 50,000 EMS-mutagenized chromosomes …


Variation In Beach Profile And Sediment Characteristics At Popham Beach, Phippsburg, Me, Kathryn Lidington Jan 2006

Variation In Beach Profile And Sediment Characteristics At Popham Beach, Phippsburg, Me, Kathryn Lidington

Undergraduate Research Symposium (UGRS)

No abstract provided.


"Inventaire Rapide Des Crustacés Décapodes De La Préfecture De Boké En Guinée" , Neil Cumberlidge Jan 2006

"Inventaire Rapide Des Crustacés Décapodes De La Préfecture De Boké En Guinée" , Neil Cumberlidge

Book Sections/Chapters

No abstract provided.


" Description Des Éspeces De Crustacés Collectées Dans Le Nord-Ouest De La Guinée" , Neil Cumberlidge Jan 2006

" Description Des Éspeces De Crustacés Collectées Dans Le Nord-Ouest De La Guinée" , Neil Cumberlidge

Book Sections/Chapters

No abstract provided.


Mechanisms Of Genotoxin-Induced Transcription And Hypermutation In P53, Barbara E. Wright, Jacqueline Reimers, Karen Schmidt, Evan Burkala, Ping Wei, Ping Wei Jan 2006

Mechanisms Of Genotoxin-Induced Transcription And Hypermutation In P53, Barbara E. Wright, Jacqueline Reimers, Karen Schmidt, Evan Burkala, Ping Wei, Ping Wei

Biological Sciences Faculty Publications

It is widely assumed that genotoxin-induced damage (e.g., G-to-T transversions) to the tumor suppressor gene, p53, is a direct cause of cancer. However, genotoxins also induce the stress response, which upregulates p53 transcription and the formation of secondary structures from ssDNA. Since unpaired bases are thermodynamically unstable and intrinsically mutable, increased transcription could be the cause of hypermutation, and thus cancer. Support for this hypothesis has been obtained by analyzing 6662 mutations in all types of cancer compared to lung and colon cancers, using the p53 mutation database. The data suggest that genotoxins have two independent effects: first, they induce …


Occurrence, Persistence, And Expansion Of Saltcedar (Tamarix Spp.) Populations In The Great Plains Of Montana, Jason P. Sexton, Anna Sala, Kevin Murray Jan 2006

Occurrence, Persistence, And Expansion Of Saltcedar (Tamarix Spp.) Populations In The Great Plains Of Montana, Jason P. Sexton, Anna Sala, Kevin Murray

Biological Sciences Faculty Publications

Saltcedar (Tamarix spp.), a shrub native to Eurasia, is associated with major alterations to wetland and riparian systems in the southwestern United States. Since the 1960s saltcedar has been naturalized in northern states of the U.S. where its growth potential and impacts are not well known. Here, we describe the occurrence, age, size, and relative cover of saltcedar populations in several river basins in central eastern Montana, USA, to identify potential patterns of spread across the region and changes in individual populations as they age. Stands were aged according to the oldest saltcedar individuals and were sampled for dominant plant …


Northern Region Landbird Monitoring Program: A Usfs-University Of Montana Partnership Designed To Provide Both Short-Term And Long-Term Feedback For Land Managers, Richard L. Hutto, Skip Kowalski Jan 2006

Northern Region Landbird Monitoring Program: A Usfs-University Of Montana Partnership Designed To Provide Both Short-Term And Long-Term Feedback For Land Managers, Richard L. Hutto, Skip Kowalski

Biological Sciences Faculty Publications

The Northern Region Landbird Monitoring Program (NRLMP) began in 1990 as a cooperative effort between the United States Forest Service (USFS) and the University of Montana. The combination of a research-oriented perspective from the University and a management-needs perspective from the National Forests within the Northern Region led to the realization that landbirds as a group might serve as a powerful tool to address more widespread monitoring needs in the USFS Northern Region. The program quickly evolved from one that was put into place specifically to use federally earmarked dollars to address neotropical migratory bird conservation, into a more general …


Analyzing Dna Microarrays With Undergraduate Statisticians, Johanna S. Hardin, Laura Hoopes, Ryan Murphy '06 Jan 2006

Analyzing Dna Microarrays With Undergraduate Statisticians, Johanna S. Hardin, Laura Hoopes, Ryan Murphy '06

Pomona Faculty Publications and Research

With advances in technology, biologists have been saddled with high dimensional data that need modern statistical methodology for analysis. DNA microarrays are able to simultaneously measure thousands of genes (and the activity of those genes) in a single sample. Biologists use microarrays to trace connections between pathways or to identify all genes that respond to a signal. The statistical tools we usually teach our undergraduates are inadequate for analyzing thousands of measurements on tens of samples. The project materials include readings on microarrays as well as computer lab activities. The topics covered include image analysis, filtering and normalization techniques, and …


Mapping And Characterization Of 18-5 And 12-5, Genes Which Potentially Link The Rhoa Signaling Pathway To The Ecdysone Response, Samuel Fox Jan 2006

Mapping And Characterization Of 18-5 And 12-5, Genes Which Potentially Link The Rhoa Signaling Pathway To The Ecdysone Response, Samuel Fox

Electronic Theses and Dissertations

Systemic steroid hormone and intracellular signaling pathways are known to act cooperatively during the development of vertebrate and invertebrate epithelia. However, the mechanism of this interaction is poorly understood. Morphogenesis of Drosophila leg imaginal disc epithelia is regulated both by the steroid hormone 20-hydroxyecdysone (ecdysone) and the RhoA GTPase signaling pathway. Recent evidence suggests that these pathways act cooperatively to control imaginal disc morphogenesis. Thus, leg imaginal disc morphogenesis is an excellent system in which to study the interaction of steroid hormone and intracellular signaling pathways. We have identified mutations in three genes, 12-5, 18-5, and 31-6, with roles in …


Rack1 Mediates Multiple Hormone Responsiveness And Developmental Processes In Arabidopsis, Hemayet Ullah Jan 2006

Rack1 Mediates Multiple Hormone Responsiveness And Developmental Processes In Arabidopsis, Hemayet Ullah

Department of Biology Faculty Publications

The scaffold protein RACK1 (Receptor for Activated C Kinase 1) serves as an integrative point for diverse signal transduction pathways. The Arabidopsis genome contains three RACK1 orthologues, however, little is known about their functions. It is reported here that one memberof this gene family, RACK1A, previously identified as the Arabidopsis homologue of the tobacco arcA gene, mediates hormone responses and plays a regulatory role in multiple developmental processes. RACK1A expresses ubiquitously in Arabidopsis. Loss-of-function mutations in RACK1A confer defects in multiple developmental processes including seed germination, leaf production, and flowering. rack1a mutants displayed reduced sensitivity to gibberellin and brassinosteroid in …


Ethnic Identity And Type 2 Diabetes Health Attitudes In Americans Of African Ancestry, Jelena Brezo, Charmaine D. Royal, Franklin Ampy, Verle Headings Jan 2006

Ethnic Identity And Type 2 Diabetes Health Attitudes In Americans Of African Ancestry, Jelena Brezo, Charmaine D. Royal, Franklin Ampy, Verle Headings

Department of Biology Faculty Publications

Background: Exploring the role of ethnic identity may be a good starting point toward a better understanding of health attitudes in different communities. This knowledge would be most useful in addressing diseases that cause significant burden and for which known prevention and morbidity-reducing strategies are effective.Objective: The main objective was to investigate possible associations between measures of ethnic identity and health attitudes toward type 2 diabetes mellitus by using a questionnaire-based measure.


African-American Mitochondrial Dnas Often Match Mtdnas Found In Multiple African Ethnic Groups [Published Correction Appears In Bmc Biol 2006; 5:13], Bert Ely, Jamie Wilson, Fatimah Linda Collier Jackson, Bruce Jackson Jan 2006

African-American Mitochondrial Dnas Often Match Mtdnas Found In Multiple African Ethnic Groups [Published Correction Appears In Bmc Biol 2006; 5:13], Bert Ely, Jamie Wilson, Fatimah Linda Collier Jackson, Bruce Jackson

Department of Biology Faculty Publications

Mitochondrial DNA (mtDNA) haplotypes have become popular tools for tracing maternal ancestry, and several companies offer this service to the general public. Numerous studies have demonstrated that human mtDNA haplotypes can be used with confidence to identify the continent where the haplotype originated. Ideally, mtDNA haplotypes could also be used to identify a particular country or ethnic group from which the maternal ancestor emanated. However, the geographic distribution of mtDNA haplotypes is greatly influenced by the movement of both individuals and population groups. Consequently, common mtDNA haplotypes are shared among multiple ethnic groups. We have studied the distribution of mtDNA …


Allostasis, Homeostasis, And The Costs Of Physiological Adaptation, Sarah C. Coste Jan 2006

Allostasis, Homeostasis, And The Costs Of Physiological Adaptation, Sarah C. Coste

Faculty Publications

Sarah Coste reviews Allostasis, Homeostasis, and the Costs of Physiological Adaptation (edited by Jay Schulkin) for the Quarterly Review of Biology.


The Cardiomyocyte Cell Cycle, Pascal J. Lafontant Jan 2006

The Cardiomyocyte Cell Cycle, Pascal J. Lafontant

Biology Faculty publications

Many forms of cardiac disease are characterized by cardiomyocyte death due to necrosis, apoptosis and/or oncosis. Recently, the notion of promoting cardiac regeneration as a means to replace damaged heart tissue has engendered considerable interest. One approach to accomplish heart muscle regeneration entails promoting cardiomyocyte cell cycle activity in the surviving myocardium. Genetically modified mice have provided useful model systems to test the efficacy of specific pathways to promote cardiomyocyte proliferation in normal and diseased hearts. For example, expression of a heart-restricted dominant interfering version of p193 (an E3 ubiquitin ligase also known as Cul7) resulted in an induction of …


Mechanism Of Shifts Of Potentials Of Hemosorbents Based On Activated Carbons Caused By Adsorption Of Organic Toxicants, Mark Goldin, Yury Goldfarb, Mikhail M. Goldin Jan 2006

Mechanism Of Shifts Of Potentials Of Hemosorbents Based On Activated Carbons Caused By Adsorption Of Organic Toxicants, Mark Goldin, Yury Goldfarb, Mikhail M. Goldin

Faculty Publications and Presentations

No abstract provided.


Dispersal Behavior Of Mosquitofish (Gambusia Holbrooki), Shireen Alemadi Jan 2006

Dispersal Behavior Of Mosquitofish (Gambusia Holbrooki), Shireen Alemadi

Electronic Theses and Dissertations

Mosquitofish (Gambusia holbrooki) are native to the southeastern United States but invasive elsewhere, and are dominant predators in many ecosystems that they inhabit. Information on dispersal behavior will help better understand and predict mosquitofish metapopulation dynamics and invasions. I experimentally tested dispersal behavior of individual mosquitofish under a range of laboratory conditions relevant to field situations. Preliminary experiments showed that gender, lighting conditions, hunger and acclimation time did not significantly affect net dispersal rate. Power analysis based on this preliminary experiment determined that 6 replicate fish were sufficient for each subsequent experiment; I used 24 fish, and each fish was …


Endothelial Cell Cortactin Phosphorylation By Src Contributes To Polymorphonuclear Leukocyte Transmigration In Vitro, L. Yang, Jennifer R. Kowalski, X. Zhan, S. M. Thomas, F. W. Luscinskas Jan 2006

Endothelial Cell Cortactin Phosphorylation By Src Contributes To Polymorphonuclear Leukocyte Transmigration In Vitro, L. Yang, Jennifer R. Kowalski, X. Zhan, S. M. Thomas, F. W. Luscinskas

Scholarship and Professional Work - LAS

The underlying mechanisms that regulate leukocyte transendothelial migration through the vascular endothelium remain unclear. Cortactin is a substrate of Src tyrosine kinases and a regulator of cytoskeletal dynamics. Previous studies demonstrated a role for Src phosphorylation of cortactin in clustering of E-selectin and intercellular cell adhesion molecule-1 around adherent leukocytes. In the current study, we used an in vitro flow model to investigate the role of Src-induced cortactin phosphorylation in endothelium during polymorphonuclear leukocyte (PMN) transmigration through human umbilical vein endothelium (HUVEC) monolayers preactivated with tumor necrosis factor-{alpha}. Inhibition of Src in HUVEC using Src kinase inhibitors PP2 and SU6656 …


Efeitos Da Radiação Ultravioleta-B Sobre A Morfologia Foliar De Arabidopsis Thaliana (L.) Heynh. (Brassicaceae), Maria Regina Torres Boeger, Mary Poulson Jan 2006

Efeitos Da Radiação Ultravioleta-B Sobre A Morfologia Foliar De Arabidopsis Thaliana (L.) Heynh. (Brassicaceae), Maria Regina Torres Boeger, Mary Poulson

Biology Faculty Scholarship

Reduction of the ozone layer results in the increase in ultraviolet radiation reaching the earth’s surface, especially the ultraviolet-B (UV-B). The increase of radiation may induce structural and physiological changes in plants, influencing their growth and development. This paper evaluates the effects of ambient UV-B radiation upon to the leaf morphology of Arabidopsis thaliana developed under controlled conditions. The seeds of A. thaliana grown in environmental chamber, with 300 μmol m-2s-1 de photosynthetically active radiation (PAR) with and without 6 kJ m-2 s-1 of radiation UV-Bbe (UV-Bbe; UV-B biologically effective). After 21 days, ten leaves of each treatment (with and …


Gis-Based Analysis Of Ice-Breeding Seal Strandings In The Gulf Of Maine, David Harris Ph.D., Sat Gupta Jan 2006

Gis-Based Analysis Of Ice-Breeding Seal Strandings In The Gulf Of Maine, David Harris Ph.D., Sat Gupta

Faculty Publications

Phoca groenlandica (harp seals) and Cystophora cristata (hooded seals), two species of ice-breeding seals, are being sighted more frequently onshore in the Gulf of Maine since 1990, but little is known about their behavior in this ecosystem. We obtained records of 904 ice-breeding seal stranding locations in the Gulf of Maine between 1996 and 2002 from NOAA Fisheries and used a geographic information system (GIS) to conduct group-wise comparisons by species (using non-parametric techniques), and to determine the predictors of high seal-stranding density (using ordinal logistic regression analysis). Compared to harp seals, hooded seals stranded closer to deep water, farther …


Glucocorticoid Hormone Levels Increase With Group Size And Parasite Load In Cliff Swallows, Samrrah A. Raouf, Linda C. Smith, Mary Bomberger Brown, John C. Wingfield, Charles R. Brown Jan 2006

Glucocorticoid Hormone Levels Increase With Group Size And Parasite Load In Cliff Swallows, Samrrah A. Raouf, Linda C. Smith, Mary Bomberger Brown, John C. Wingfield, Charles R. Brown

School of Biological Sciences: Faculty Publications

Animals often cope with adverse events by releasing glucocorticoid hormones, which in turn promote increased energy assimilation. In captive animals, crowding also leads to increased glucocorticoid activity, probably because of increased levels of social competition. We investigated how group size and ectoparasite infestations affected endogenous levels of the glucocorticoid hormone, corticosterone, in colonial cliff swallows, Petrochelidon pyrrhonota, in southwestern Nebraska, USA. Parasites were removed from some colonies by fumigating nests. Baseline levels of corticosterone in breeding adults varied significantly with whether parasites were present, colony size (measured by total number of active nests at a site), and nesting stage. …


Nonparametric Estimation Of Natural Selection On A Quantitative Trait Using Mark-Recapture Data, Olivier Gimenez, Rita Covas, Charles R. Brown, Mark D. Anderson, Mary Bomberger Brown, Thomas Lenormand Jan 2006

Nonparametric Estimation Of Natural Selection On A Quantitative Trait Using Mark-Recapture Data, Olivier Gimenez, Rita Covas, Charles R. Brown, Mark D. Anderson, Mary Bomberger Brown, Thomas Lenormand

School of Biological Sciences: Faculty Publications

Assessing natural selection on a phenotypic trait in wild populations is of primary importance for evolutionary ecologists. To cope with the imperfect detection of individuals inherent to monitoring in the wild, we develop a nonparametric method for evaluating the form of natural selection on a quantitative trait using mark-recapture data. Our approach uses penalized splines to achieve flexibility in exploring the form of natural selection by avoiding the need to specify an a priori parametric function. If needed, it can help in suggesting a new parametric model. We employ Markov chain Monte Carlo sampling in a Bayesian framework to estimate …


Regulation Of Mercury Resistance In The Crenarchaeote Sulfolobus Solfataricus, James Schelert, Melissa Drozda, Vidula Dixit, Amanda Dillman, Paul H. Blum Jan 2006

Regulation Of Mercury Resistance In The Crenarchaeote Sulfolobus Solfataricus, James Schelert, Melissa Drozda, Vidula Dixit, Amanda Dillman, Paul H. Blum

School of Biological Sciences: Faculty Publications

Mercuric ion, Hg(II), inactivates generalized transcription in the crenarchaeote Sulfolobus solfataricus. Metal

challenge simultaneously derepresses transcription of mercuric reductase (merA) by interacting with the

archaeal transcription factor aMerR. Northern blot and primer extension analyses identified two additional

Hg(II)-inducible S. solfataricus genes, merH and merI (SSO2690), located on either side of merA. Transcription

initiating upstream of merH at promoter merHp was metal inducible and extended through merA and merI,

producing a merHAI transcript. Northern analysis of a merRA double mutant produced by linear DNA

recombination demonstrated merHp promoter activity was dependent on aMerR to overcome Hg(II) …


Fire Does Not Alter Vegetation In Infertile Prairie, Johannes M.H. Knops Jan 2006

Fire Does Not Alter Vegetation In Infertile Prairie, Johannes M.H. Knops

School of Biological Sciences: Faculty Publications

The paradigm in prairie ecology is that fire is one of the key factors deter-mining vegetation composition. fire can impact grassland ecosystems in various ways, including changing plant species composition and inducing nitro-gen loss. I found that 17 years of different burning frequencies in infertile grassland had only a minor impact on the vegetation composition and diversity. The only major impact from increasing the frequency of fires was a decrease of Poa pratensis abundance. However, other plant species did not r-spond to the change in Poa abundance. This result contrasts with previous studies in savannas and more productive grasslands, where …


Can Environmental Variation Generate Positive Indirect Effects In A Model Of Shared Predation?, Chad Brassil Jan 2006

Can Environmental Variation Generate Positive Indirect Effects In A Model Of Shared Predation?, Chad Brassil

School of Biological Sciences: Faculty Publications

Classic models of apparent competition predict negative indirect effects between prey with a shared enemy. If predator per capita growth rates are nonlinear, then endogenously generated periodic cycles are predicted to generate less negative or even positive indirect effects between prey. Here I determine how exogenous mechanisms such as environmental variation could modify indirect effects. I find that exogenous variation can have a broader range of effects on indirect interactions than endogenously generated cycles. Indirect effects are altered by environmental variation even in simple models for which the per capita growth rate of the predator species is a linear function …


The Offspring/Clutch Size Tradeoff In Mammals, E. L. Charnov, S.K. Morgan Ernest Jan 2006

The Offspring/Clutch Size Tradeoff In Mammals, E. L. Charnov, S.K. Morgan Ernest

Biology Faculty Publications

The Smith‐Fretwell model for optimal offspring size assumes the existence of an inverse proportional relationship (i.e., trade‐off) between the number of offspring and the amount of resources invested in an individual offspring; virtually all of the many models derived from theirs make the same trade‐off assumption. Over the last 30 years it has become apparent that the predicted proportionality is often not observed when evaluated across species. We develop a general allometric approach to correct for size‐related differences in the resources available for reproduction. Using data on mammals, we demonstrate that the predicted inverse proportional relationship between number of offspring …


Intra-Guild Compensation Regulatesspecies Richness In Desert Rodents: Reply, J. R. Goheen, Ethan P. White, S.K. Morgan Ernest, J. H. Brown Jan 2006

Intra-Guild Compensation Regulatesspecies Richness In Desert Rodents: Reply, J. R. Goheen, Ethan P. White, S.K. Morgan Ernest, J. H. Brown

Biology Faculty Publications

No abstract provided.


Life History And Biology Of Forbestra Olivencia (Ithomiinae, Nymphalidae), Ryan I. Hill Jan 2006

Life History And Biology Of Forbestra Olivencia (Ithomiinae, Nymphalidae), Ryan I. Hill

College of the Pacific Faculty Articles

Forbestra is the only mechanitine genus lacking a thorough life history description and little is known of its biology. Accordingly I describe the immature stages including first instar chaetotaxy, and provide observations on the biology of Forbestra olivencia from Garza Cocha in eastern Ecuador. Morphological characters from the early stages of Forbestra olivencia are identified that are unique to Forbestra and support the close relationship of Forbestra and Mechanitis. Forbestra olivencia was a moderately common butterfly at Garza Cocha during the sample period, far outnumbering other sympatric Forbestra. Ecological observations demonstrate similarities between F. olivencia and Mechanitis, but suggest F. …