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2004

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Articles 211 - 240 of 418

Full-Text Articles in Biology

Phylogenetic Signal And The Utility Of 12s And 16s Mtdna In Frog Phylogeny, S. Hertwig, Rafael O. De Sá, A. Haas Feb 2004

Phylogenetic Signal And The Utility Of 12s And 16s Mtdna In Frog Phylogeny, S. Hertwig, Rafael O. De Sá, A. Haas

Biology Faculty Publications

Genes selected for a phylogenetic study need to contain conserved information that reflects the phylogenetic history at the specific taxonomic level of interest. Mitochondrial ribosomal genes have been used for a wide range of phylogenetic questions in general and in anuran systematics in particular. We checked the plausibility of phylogenetic reconstructions in anurans that were built from commonly used 12S and 16S rRNA gene sequences. For up to 27 species arranged in taxon sets of graded inclusiveness, we inferred phylogenetic hypotheses based on different apriori decisions, i.e. choice of alignment method and alignment parameters, including/excluding variable sites, choice of reconstruction …

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The Vascular Flora Of The Palo Alto National Battlefield Historic Site, Cameron County, Texas, Robert I. Lonard, Alfred T. Richardson, Norman L. Richard Feb 2004

The Vascular Flora Of The Palo Alto National Battlefield Historic Site, Cameron County, Texas, Robert I. Lonard, Alfred T. Richardson, Norman L. Richard

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

A checklist is provided of the vascular plant taxa of the 1,376 ha Palo Alto Battlefield National Historic Site (PABNHS) in Cameron County of south Texas. PABNHS consists of four plant communities: resacas and tanks, salt flats, brush-grasslands and coastal marshes. Vascular plants of disturbed sites are noted. Two hundred forty-three taxa in 66 families are documented and their community affiliations are given. Three families, Poaceae, Asteraceae and Fabaceae contain 37.5% of the species richness at PABNHS.

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Flagellar Radial Spoke Protein 2 Is A Calmodulin Binding Protein Required For Motility In Chlamydomonas Reinhardtii, Pinfen Yang, Chun Yang, Winfield S. Sale Feb 2004

Flagellar Radial Spoke Protein 2 Is A Calmodulin Binding Protein Required For Motility In Chlamydomonas Reinhardtii, Pinfen Yang, Chun Yang, Winfield S. Sale

Biological Sciences Faculty Research and Publications

Genetic and morphological studies have revealed that the radial spokes regulate ciliary and flagellar bending. Functional and biochemical analysis and the discovery of calmodulin in the radial spokes suggest that the regulatory mechanism involves control of axonemal protein phosphorylation and calcium binding to spoke proteins. To identify potential regulatory proteins in the radial spoke, in-gel kinase assays were performed on isolated axonemes and radial spoke fractions. The results indicated that radial spoke protein 2 (RSP2) can bind ATP and transfer phosphate in vitro. RSP2 was cloned and mapped to the PF24 locus, a gene required for motility. Sequencing revealed that …

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Walking And Running In The Red-Legged Running Frog, Kassina Maculata, Anna N. Ahn, E Furrow, Andrew A. Biewener Jan 2004

Walking And Running In The Red-Legged Running Frog, Kassina Maculata, Anna N. Ahn, E Furrow, Andrew A. Biewener

All HMC Faculty Publications and Research

Although most frog species are specialized for jumping or swimming, Kassina maculata (red-legged running frog) primarily uses a third type of locomotion during which the hindlimbs alternate. In the present study, we examined Kassina's distinct locomotory mode to determine whether these frogs walk or run and how their gait may change with speed. We used multiple methods to distinguish between terrestrial gaits: the existence or absence of an aerial phase, duty factor, relative footfall patterns and the mechanics of the animal's center of mass (COM). To measure kinematic and kinetic variables, we recorded digital video as the animals moved …

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Identifying Character Non-Independence In Phylogenetic Data Using Data Mining Techniques, Jennifer Leopold, Anne M. Maglia, M. Thakur, B. Patel, Fikret ErçAl Jan 2004

Identifying Character Non-Independence In Phylogenetic Data Using Data Mining Techniques, Jennifer Leopold, Anne M. Maglia, M. Thakur, B. Patel, Fikret ErçAl

Computer Science Faculty Research & Creative Works

Undiscovered relationships in a data set may confound analyses, particularly those that assume data independence. Such problems occur when characters used for phylogenetic analyses are not independent of one another. A main assumption of phylogenetic inference methods such as maximum likelihood and parsimony is that each character serves as an independent hypothesis of evolution. When this assumption is violated, the resulting phylogeny may not reflect true evolutionary history. Therefore, it is imperative that character non-independence be identified prior to phylogenetic analyses. To identify dependencies between phylogenetic characters, we applied three data mining techniques: 1) Bayesian networks, 2) decision tree induction, …

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Science On The Rise In Developing Countries, Milena Holmgren, Stefan A. Schnitzer Jan 2004

Science On The Rise In Developing Countries, Milena Holmgren, Stefan A. Schnitzer

Biological Sciences Faculty Research and Publications

No abstract provided.

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Appendix C: General Data, Problems In Environmental Science Course (Biology 493), Colby College, Colby Environmental Assessment Team, Colby College Jan 2004

Appendix C: General Data, Problems In Environmental Science Course (Biology 493), Colby College, Colby Environmental Assessment Team, Colby College

Colby College Watershed Study: Togus Pond (2004)

No abstract provided.

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Fall Data Report, Problems In Environmental Science Course (Biology 493), Colby College, Colby Environmental Assessment Team, Colby College Jan 2004

Fall Data Report, Problems In Environmental Science Course (Biology 493), Colby College, Colby Environmental Assessment Team, Colby College

Colby College Watershed Study: Togus Pond (2004)

No abstract provided.

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Total Phosphorus, Colby College, Problems In Environmental Science Course (Biology 493), Colby College, Colby Environmental Assessment Team, Colby College Jan 2004

Total Phosphorus, Colby College, Problems In Environmental Science Course (Biology 493), Colby College, Colby Environmental Assessment Team, Colby College

Colby College Watershed Study: Togus Pond (2004)

No abstract provided.

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An Assessment Of Water Quality, Colby College, Problems In Environmental Science Course (Biology 493), Colby College Jan 2004

An Assessment Of Water Quality, Colby College, Problems In Environmental Science Course (Biology 493), Colby College

Colby College Watershed Study: Togus Pond (2004)

No abstract provided.

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Water Quality Results From Togus Pond, Colby College, Problems In Environmental Science Course (Biology 493), Colby College Jan 2004

Water Quality Results From Togus Pond, Colby College, Problems In Environmental Science Course (Biology 493), Colby College

Colby College Watershed Study: Togus Pond (2004)

No abstract provided.

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Forest Fragmentation And The Distribution, Abundance And Conservation Of The Tana River Red Colobus ( Procolobus Rufomitratus), David N.M. Mbora, Douglas B. Meikle Jan 2004

Forest Fragmentation And The Distribution, Abundance And Conservation Of The Tana River Red Colobus ( Procolobus Rufomitratus), David N.M. Mbora, Douglas B. Meikle

Biology

Evidence suggests that habitat heterogeneity, disturbance, disease, predation and food resources influence primate population abundance. However, few studies have focused on what habitat factors determine the probability that a primate species will occur in a habitat fragment. We analysed forest habitat and colobus population attributes to determine factors that influenced occurrence and abundance of the critically endangered Tana River red colobus. The probability of colobus inhabiting forests was positively related to the relative amount of habitat edge and canopy tree species composition. Most of the variance in the density of colobus monkeys was explained by basal area of food trees …

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The Effect Of Loading On Disturbance Sounds Of The Atlantic Croaker Micropogonius Undulatus: Air Versus Water, Michael L. Fine, Justin Schrinel, Timothy M. Cameron Jan 2004

The Effect Of Loading On Disturbance Sounds Of The Atlantic Croaker Micropogonius Undulatus: Air Versus Water, Michael L. Fine, Justin Schrinel, Timothy M. Cameron

Biology Publications

Physiological work on fish sound production may require exposure of the swimbladder to air, which will change its loading (radiation mass and resistance) and could affect parameters of emitted sounds. This issue was examined in Atlantic croaker Micropogonius chromis by recording sounds from the same individuals in air and water. Although sonograms appear relatively similar in both cases, pulse duration is longer because of decreased damping, and sharpness of tuning (Q factor) is higher in water. However, pulse repetition rate and dominant frequency are unaffected. With appropriate caution it is suggested that sounds recorded in air can provide a useful …

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Influence Of The Pacific Decadal Oscillation On Hydrochemistry Of The Rio Grande, Usa, And Mexico, Fasong Yuan, Seiichi Miyamoto Jan 2004

Influence Of The Pacific Decadal Oscillation On Hydrochemistry Of The Rio Grande, Usa, And Mexico, Fasong Yuan, Seiichi Miyamoto

Biological, Geological, and Environmental Faculty Publications

The hydrochemistry has been examined using the major element composition of river water at 12 gauging stations along the Rio Grande. As the Rio Grande Basin consists of two watersheds that have different hydrologic and climatic regimes, two chloride concentration records from the El Paso and Falcon Dam gauging stations have been extracted to reflect long-term variability in river chemistry of the upper and lower basins over the last 50–70 years. Both records contain decadal variability in chloride concentration but are different in nature. The chloride concentration record from the upper basin displays a distinct pattern of decadal variability similar …

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Caenorhabditis Elegans Atx-2 Promotes Germline Proliferation And The Oocyte Fate, Eleanor M. Maine, Dave Hansen, Deborah Springer, Valarie E. Vought Jan 2004

Caenorhabditis Elegans Atx-2 Promotes Germline Proliferation And The Oocyte Fate, Eleanor M. Maine, Dave Hansen, Deborah Springer, Valarie E. Vought

Biology - All Scholarship

In the Caenorhabditis elegans germline, proliferation is induced by Notch-type signaling. Entry of germ cells into meiosis is triggered by activity of the GLD-1 and GLD-2 pathways, which function redundantly to promote meiosis and/or inhibit proliferation. Activation of the germline Notch-type receptor, GLP-1, ultimately inhibits the activities of the GLD-1 and GLD-2 pathways. We previously identified several ego (enhancer of glp-1) genes that promote germline proliferation and interact genetically with the GLP-1 signaling pathway. Here, we show that atx-2 is an ego gene. Our data suggest that ATX-2 is not a positive regulator of the GLP-1 signaling pathway and GLP-1 …

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Renesting Decisions And Annual Fecundity Of Female Dickcissels (Spiza Americana) In Illinois, Jeffery W. Walk, Kevin Wentworth, Eric L. Kershner, Eric K. Bollinger, Richard E. Warner Jan 2004

Renesting Decisions And Annual Fecundity Of Female Dickcissels (Spiza Americana) In Illinois, Jeffery W. Walk, Kevin Wentworth, Eric L. Kershner, Eric K. Bollinger, Richard E. Warner

Faculty Research & Creative Activity

T.-Renesting decisions and annual fecundity are crucial for interpreting other demographic information, yet are infrequently reported. We used radiotelemetry to monitor female Dickcissels (Spiza americana) throughout the 1999 and 2000 breeding seasons in south- eastern Illinois. Overall fecundity (regardless of whether females remained in the study area throughout the breeding season) was 0.61 ? 0.13 female fledglings per year. Of females that re- mained within the study area, 94% fledged young (1.25 ? 0.15 female fledglings per year). Most females (62%) that experienced nest failure emigrated from the study area (moved >10 km) in 2.8 ? 0.6 days; others (36%) …

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Interactions Between The Nudibranch Okenia Zoobotryon And Its Bryozoan, Nicole Robinson Jan 2004

Interactions Between The Nudibranch Okenia Zoobotryon And Its Bryozoan, Nicole Robinson

Electronic Theses and Dissertations

In the Indian River Lagoon, the nudibranch Okenia zoobotryon and its egg masses are found attached to the bryozoan Zoobotryon verticillatum throughout the year. Okenia zoobotryon is thought to live, feed, and reproduce exclusively on Z. verticillatum, which would make this a very specialized predator-prey interaction. The primary goal of my study was to document certain aspects of the ecological and chemical relationships between Z. verticillatum and O. zoobotryon. Specifically, I wanted to understand the cues used by the nudibranch to locate and remain on Z. verticillatum. Population surveys on Z. verticillatum, as well as other potential hosts, were performed. …

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Synthesis Of The Novel Crown Ether 1 ,9-Dioxa-4,6-Dithiacycloundecane, Cassie Booth Jan 2004

Synthesis Of The Novel Crown Ether 1 ,9-Dioxa-4,6-Dithiacycloundecane, Cassie Booth

Capstone Research Projects

Attempts to produce novel crowns, incorporating a thioacetal fragment, were made via two synthetic pathways. Despite the well-established reactions found in path A (see figure 3), this method failed to produce the desired crown. Path B, a one-pot reaction originally designed to close rings via the addition of a thioacetal fragment, yielded an oily product that was purified with a silica gel column (48.3% yield). Initial analysis by 1H NMR showed a structure consistent with that of the desired crown (figure 2). Mass spectroscopy was used to verify product identity, confirming the creation of our target molecule 1 ,9-dioxa-4,6-dithiacycloundecane.

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Analysis Of Common Tick Species Collected From The Chattanooga-Hamilton Region Of Tennessee And The Correlation To Reported Cases Of Tick-Borne Diseases, Astrid Von-Walter Jan 2004

Analysis Of Common Tick Species Collected From The Chattanooga-Hamilton Region Of Tennessee And The Correlation To Reported Cases Of Tick-Borne Diseases, Astrid Von-Walter

Capstone Research Projects

Amblyomma americanum, Dermacentor variabilis, Ixodes scapularis, and Rhipicephalus sanguineus are three-host ticks commonly found in the Chattanooga-Hamilton region of Tennessee. The first three species are medically important because they are known to transmit Ehrlichiosis, Rocky Mountain spotted fever, and Lyme disease, respectively. Rhipicephalus is not known to vector any pathogens infecting humans; therefore, not clinically significant. The focus of this study was to correlate the population of A. americanum, D. variabilis, and I. scapularis in the Chattanooga region to reported cases of tick -borne diseases. There was a direct relationship between the frequency of D. variabilis and the reported cases …

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Systematic And Comparative Anatomy Of Maxillarieae (Orchidaceae), Sans Oncidiinae, William Louis Stern, Walter S. Judd, Barbara S. Carlsward Jan 2004

Systematic And Comparative Anatomy Of Maxillarieae (Orchidaceae), Sans Oncidiinae, William Louis Stern, Walter S. Judd, Barbara S. Carlsward

Faculty Research & Creative Activity

On the basis of floral and vegetative morphology, 63 tropical American genera have been recognized within Maxillarieae. We were able to examine anatomical material of all subtribes, excluding Oncidiinae. Stegmata with conical silica bodies occur in leaves and stems of all subtribes excluding Ornithocephalinae, and pericyclic stegmata found in roots are characteristic of Lycastinae. Lycastinae and Maxillariinae are characterized by foliar glands, foliar fibre bundles and tilosomes. Endodermal cells are U-thickened in most Zygopetalinae; O-thickened in most Lycastinae, Ornithocephalinae and Telipogoninae; variously thickened in Maxillariinae; and thin-walled in Cryptarrhena lunata. Water-storage cells varied from thin-walled to variously banded throughout Maxillarieae. …

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Demographics And The Ecological Role Of The Channel Catfish (Ictalurus Punctatus) In Commercially Exploited And Unexploited Reaches Of The Wabash River With Implications For The Flathead Catfish (Pylodictis Olivaris), Robert Colombo Jan 2004

Demographics And The Ecological Role Of The Channel Catfish (Ictalurus Punctatus) In Commercially Exploited And Unexploited Reaches Of The Wabash River With Implications For The Flathead Catfish (Pylodictis Olivaris), Robert Colombo

Faculty Research & Creative Activity

Catfish are a major component of the Wabash River fish assemblage and are commercially fished below river kilometer (Rkm) 500. From Rkm 322 through 499 the commercial fishery is subjected only to Indiana fishing regulations. In this reach of river, there is a 254-mm minimum total length limit on both sport and commercially harvested catfish. Below RM 322, the Wabash River forms the state boundary of Indiana and Illinois. In this region of river there are two different length limits on commercially harvested catfish with Indiana having a 254-mm length limit and Illinois having a 381-mm length limit. There is …

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Using Wildlife As Receptor Species: A Landscape, Karen F. Gaines, Dwayne E. Porter, Susan A. Dyer, Gary R. Wein, John E. Pinder Iii, I. Lehr Brisbin Jr. Jan 2004

Using Wildlife As Receptor Species: A Landscape, Karen F. Gaines, Dwayne E. Porter, Susan A. Dyer, Gary R. Wein, John E. Pinder Iii, I. Lehr Brisbin Jr.

Faculty Research & Creative Activity

To assist risk assessors at the Department of Energy’s Savannah River Site (SRS), a Geographic Information System (GIS) application was developed to provide relevant information about specific receptor species of resident wildlife that can be used for ecological risk assessment. Information was obtained from an extensive literature review of publications and reports on vertebrate- and contaminant- related research since 1954 and linked to a GIS. Although this GIS is a useful tool for risk assessors because the data quality is high, it does not describe the species’ site-wide spatial distribution or life history, which may be crucial when developing a …

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Renesting Decisions And Annual Fecundity Of Female Dickcissels (Spiza Americana) In Illinois, Jeffery Walk, Kevin Wentworth, Eric Kershner, Eric Bollinger, Richard Warner Jan 2004

Renesting Decisions And Annual Fecundity Of Female Dickcissels (Spiza Americana) In Illinois, Jeffery Walk, Kevin Wentworth, Eric Kershner, Eric Bollinger, Richard Warner

Faculty Research & Creative Activity

T.-Renesting decisions and annual fecundity are crucial for interpreting other demographic information, yet are infrequently reported. We used radiotelemetry to monitor female Dickcissels (Spiza americana) throughout the 1999 and 2000 breeding seasons in south- eastern Illinois. Overall fecundity (regardless of whether females remained in the study area throughout the breeding season) was 0.61 ? 0.13 female fledglings per year. Of females that re- mained within the study area, 94% fledged young (1.25 ? 0.15 female fledglings per year). Most females (62%) that experienced nest failure emigrated from the study area (moved >10 km) in 2.8 ? 0.6 days; others (36%) …

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Systematic And Comparative Anatomy Of Maxillarieae (Orchidaceae), Sans Oncidiinae, William Stern, Walter Judd, Barbara Carlsward Jan 2004

Systematic And Comparative Anatomy Of Maxillarieae (Orchidaceae), Sans Oncidiinae, William Stern, Walter Judd, Barbara Carlsward

Faculty Research & Creative Activity

On the basis of floral and vegetative morphology, 63 tropical American genera have been recognized within Maxillarieae. We were able to examine anatomical material of all subtribes, excluding Oncidiinae. Stegmata with conical silica bodies occur in leaves and stems of all subtribes excluding Ornithocephalinae, and pericyclic stegmata found in roots are characteristic of Lycastinae. Lycastinae and Maxillariinae are characterized by foliar glands, foliar fibre bundles and tilosomes. Endodermal cells are U-thickened in most Zygopetalinae; O-thickened in most Lycastinae, Ornithocephalinae and Telipogoninae; variously thickened in Maxillariinae; and thin-walled in Cryptarrhena lunata. Water-storage cells varied from thin-walled to variously banded throughout Maxillarieae. …

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Guano, Donald A. Mcfarlane Jan 2004

Guano, Donald A. Mcfarlane

WM Keck Science Faculty Papers

This is an encyclopedia article.

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Effects Of Cooking On Radiocesium In Fish From The Savannah River: Exposure Differences For The Public, Joanna Burger, Karen F. Gaines, C. Shane Boring, J. Snodgrass, W. L. Stephens Jr., M. Gochfeld Jan 2004

Effects Of Cooking On Radiocesium In Fish From The Savannah River: Exposure Differences For The Public, Joanna Burger, Karen F. Gaines, C. Shane Boring, J. Snodgrass, W. L. Stephens Jr., M. Gochfeld

Faculty Research & Creative Activity

Understanding the factors that contribute to the risk from fish consumption is an important public health concern because of potential adverse effects of radionuclides, organochlorines, other pesticides, and mercury. Risk from consumption is normally computed on the basis of contaminant levels in fish, meal frequency, and meal size, yet cooking practices may also affect risk. This study examines the effect of deep-frying on radiocesium (137Cs) levels and risk to people fishing along the Savannah River. South Carolina and Georgia have issued consumption advisories for the Savannah River, based partly on 137Cs. 137Cs levels were significantly higher in the cooked fish …

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Ig V Region Restrictions In Human Chronic Lymphocytic Leukemia Suggest Some Cases Have A Common Origin, Grant R. Kolar, J. Donald Capra Jan 2004

Ig V Region Restrictions In Human Chronic Lymphocytic Leukemia Suggest Some Cases Have A Common Origin, Grant R. Kolar, J. Donald Capra

Biological Sciences Faculty Research & Creative Works

The factors that contribute to the development of B cell chronic lymphocytic leukemia (B-CLL) are unknown, and the groups of individuals at the greatest risk for developing this common leukemia are not well defined. Molecular features are important for classifying cases of B-CLL, and it is now apparent that similarities among Ig rearrangements between patients may give important clues to the origin of this disease (see the related article beginning on page 1008).

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Ig V Region Restrictions In Human Chronic Lymphocytic Leukemia Suggest Some Cases Have A Common Origin, Grant R. Kolar, J. Donald Capra Jan 2004

Ig V Region Restrictions In Human Chronic Lymphocytic Leukemia Suggest Some Cases Have A Common Origin, Grant R. Kolar, J. Donald Capra

Biological Sciences Faculty Research & Creative Works

The factors that contribute to the development of B cell chronic lymphocytic leukemia (B-CLL) are unknown, and the groups of individuals at the greatest risk for developing this common leukemia are not well defined. Molecular features are important for classifying cases of B-CLL, and it is now apparent that similarities among Ig rearrangements between patients may give important clues to the origin of this disease (see the related article beginning on page 1008).

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Human Immunoglobulin Selection Associated With Class Switch And Possible Tolerogenic Origins For Cδ Class-Switched B Cells, Nai Ying Zheng, Kenneth Wilson, Xiaojian Wang, Angela Boston, Grant Kolar, Stephen M. Jackson, Yong Jun Liu, Virginia Pascual, J. Donald Capra, Patrick C. Wilson Jan 2004

Human Immunoglobulin Selection Associated With Class Switch And Possible Tolerogenic Origins For Cδ Class-Switched B Cells, Nai Ying Zheng, Kenneth Wilson, Xiaojian Wang, Angela Boston, Grant Kolar, Stephen M. Jackson, Yong Jun Liu, Virginia Pascual, J. Donald Capra, Patrick C. Wilson

Biological Sciences Faculty Research & Creative Works

Current paradigms of peripheral B cell selection suggest that autoreactive B cells are controlled by clonal deletion, anergy, and developmental arrest. We report that changes to the human antibody repertoire likely resulting from these mechanisms both for a well-characterized autoreactivity from antibodies encoded by the VH4-34 gene and for other hallmarks of an autoreactive repertoire are apparent mainly for class-switched B cells and not for IgM germinal center, IgM memory, or IgM plasma cells. Other possible indicators of autoreactivity found selected with immunoglobulin class include JH6 gene segment usage, increased frequency of B cells with long third hypervariable regions, and …

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Hamlet Revisited: How Evolution Really Works, William D. Stansfield Jan 2004

Hamlet Revisited: How Evolution Really Works, William D. Stansfield

Biological Sciences

Delves into the artificial programs that are merely metaphors for the processes of organic evolution. Relation of this organic evolution with the phrases in the play "Hamlet" of Shakespeare; Disadvantage of using these metaphors as educational tools; Definition of various kinds of patterns for evolution.

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