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2004

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Articles 121 - 150 of 418

Full-Text Articles in Biology

Combining Paternally And Maternally Inherited Mitochondrial Dna For Analysis Of Population Structure In Mussels, Robert A. Krebs Jun 2004

Combining Paternally And Maternally Inherited Mitochondrial Dna For Analysis Of Population Structure In Mussels, Robert A. Krebs

Biological, Geological, and Environmental Faculty Publications

Sequence divergence for a fragment of the 16S rRNA gene was compared to identify the advantages in using mitochondrial genes that descend separately through the female and male lineages to examine population structure. The test compared divergence among four local species of freshwater mussels (Unionidae) and was extended to multiple populations of one species, Pyganodon grandis. For the same gene, the male-inherited sequences diverged at a faster rate, producing longer branch lengths in the phylogenies. Of particular use were sequences extracted from P. grandis populations from the southern region of the Lake Erie watershed (Ohio, USA); five male-inherited haplotypes were …


Moving From Pattern To Process: Coexistence Mechanisms Under Intermediate Disturbance Regimes, Katriona Shea, Stephen H. Roxburgh, Emily Rauschert Jun 2004

Moving From Pattern To Process: Coexistence Mechanisms Under Intermediate Disturbance Regimes, Katriona Shea, Stephen H. Roxburgh, Emily Rauschert

Biological, Geological, and Environmental Faculty Publications

Coexistence mechanisms that require environmental variation to operate contribute importantly to the maintenance of biodiversity. One famous hypothesis of diversity maintenance under disturbance is the intermediate disturbance hypothesis (IDH). The IDH proposes patterns of peaked diversity under intermediate disturbance regimes, based on a tension between competitively superior species and species which can rapidly colonize following disturbance. We review the literature, and describe recent research that suggests that more than one underlying mechanism can generate this unimodal diversity pattern in disturbed environments. Several exciting emerging research areas are identified, including interactions between disturbance types, operation of the IDH in multi-trophic systems, …


A Plasmodium Gene Family Encoding Maurer’S Cleft Membrane Proteins: Structural Properties And Expression Profiling, Tobili Y. Sam-Yellowe, Laurence Florens, Jeffrey R. Johnson, Tongmin Wang, Judith A. Drazba, Karine G. Le Roch, Yingyao Zhou, Serge Batalov, Daniel J. Carucci Jun 2004

A Plasmodium Gene Family Encoding Maurer’S Cleft Membrane Proteins: Structural Properties And Expression Profiling, Tobili Y. Sam-Yellowe, Laurence Florens, Jeffrey R. Johnson, Tongmin Wang, Judith A. Drazba, Karine G. Le Roch, Yingyao Zhou, Serge Batalov, Daniel J. Carucci

Biological, Geological, and Environmental Faculty Publications

Upon invasion of the erythrocyte cell, the malaria parasite remodels its environment; in particular, it establishes a complex membrane network, which connects the parasitophorous vacuole to the host plasma membrane and is involved in protein transport and trafficking. We have identified a novel subtelomeric gene family in Plasmodium falciparum that encodes II transmembrane proteins localized to the Maurer's clefts. Using coimmunoprecipitation and shotgun proteomics, we were able to enrich specifically for these proteins and detect distinct peptides, allowing us to conclude that four to 10 products were present at a given time. Nearly all of the Pfmc-2tm genes are transcribed …


Nitric Oxide Is Involved In Growth Regulation And Re-Orientation Of Pollen Tubes, Ana Margarida Prado, D. M. Porterfield, José A. Feijó Jun 2004

Nitric Oxide Is Involved In Growth Regulation And Re-Orientation Of Pollen Tubes, Ana Margarida Prado, D. M. Porterfield, José A. Feijó

Biological Sciences Faculty Research & Creative Works

Nitric oxide (NO) controls diverse functions in many cells and organs of animals. It is also produced in plants and has a variety of effects, but little is known about their underlying mechanisms. in the present study, we have discovered a role for NO in the regulation of pollen tube growth, a fast tip-growing cellular system. Pollen tubes must be precisely oriented inside the anatomically complex female ovary in order to deliver sperm. We hypothesized that NO could play a role in this guidance and tested this hypothesis by challenging the growth of pollen tubes with an external NO point …


Watercolors In The Coastal Zone: What Can We See?, Oscar Schofield, Robert A. Arnone, W. Paul Bissett, Tommy D. Dickey, Curtis O. Davis, Zoe Finkel, Matthew Oliver, Mark A. Moline Jun 2004

Watercolors In The Coastal Zone: What Can We See?, Oscar Schofield, Robert A. Arnone, W. Paul Bissett, Tommy D. Dickey, Curtis O. Davis, Zoe Finkel, Matthew Oliver, Mark A. Moline

Biological Sciences

No abstract provided.


Alfred Russel Wallace: A Capsule Biography, Charles H. Smith Jun 2004

Alfred Russel Wallace: A Capsule Biography, Charles H. Smith

DLPS Faculty Publications

No abstract provided.


The New Age Of Hyperspectral Oceanography, Grace Chang, Kevin Mahoney, Amanda Briggs-Whitmire, David Kohler, Curtis Mobley, Marlon Lewis, Mark A. Moline, Emmanuel Boss, Minsu Kim, William Philpot, Tommy Dickey Jun 2004

The New Age Of Hyperspectral Oceanography, Grace Chang, Kevin Mahoney, Amanda Briggs-Whitmire, David Kohler, Curtis Mobley, Marlon Lewis, Mark A. Moline, Emmanuel Boss, Minsu Kim, William Philpot, Tommy Dickey

Biological Sciences

No abstract provided.


Integrating Research And Teaching Labs With The Module Evolution Approach, Michael S. Reagan Jun 2004

Integrating Research And Teaching Labs With The Module Evolution Approach, Michael S. Reagan

Biology Faculty Publications

No abstract provided.


The Impact Of Species Concept On Biodiversity Studies, Keith A. Crandall, Paul-Michael Agapow, Olaf R. P. Bininda-Emonds, John L. Gittleman, Georgina M. Mace, Jonathon C. Marshall, Andy Purvis Jun 2004

The Impact Of Species Concept On Biodiversity Studies, Keith A. Crandall, Paul-Michael Agapow, Olaf R. P. Bininda-Emonds, John L. Gittleman, Georgina M. Mace, Jonathon C. Marshall, Andy Purvis

Faculty Publications

Species are defined using a variety of different operational techniques. While discussion of the various methodologies has previously been restricted mostly to taxonomists, the demarcation of species is also crucial for conservation biology. Unfortunately, different methods of diagnosing species can arrive at different entities. Most prominently, it is widely thought that use of a phylogenetic species concept may lead to recognition of a far greater number of much less inclusive units. As a result, studies of the same group of organisms can produce not only different species identities but also different species range and number of individuals. To assess the …


The N-Terminal Prodomain Of Sv23 Is Essential For The Assembly Of A Functional Vitelline Membrane Network In Drosophila, Anita L. Manogaran, Gail L. Waring Jun 2004

The N-Terminal Prodomain Of Sv23 Is Essential For The Assembly Of A Functional Vitelline Membrane Network In Drosophila, Anita L. Manogaran, Gail L. Waring

Biological Sciences Faculty Research and Publications

The vitelline membrane is a specialized extracellular matrix that surrounds and protects the oocyte. Recent studies indicate that it also serves as a storage site for embryonic pattern determinants. sV23, a major vitelline membrane protein, is essential for the morphogenesis of the vitelline membrane as sV23 protein null mutants lay flaccid, infertile eggs. By analyzing a series of sV23 mutant transgenes in the sV23 protein null genetic background, we have shown that sV23 is secreted as a proprotein in functional excess and that C- and N-terminal prodomains are removed successively, following its deposition in the extracellular space. Although a target …


Heritability Of Nectar Traits: Why Do We Know So Little?, Randall J. Mitchell Jun 2004

Heritability Of Nectar Traits: Why Do We Know So Little?, Randall J. Mitchell

Biology Faculty Research

Although floral and extrafloral nectar traits are important for plant reproduction and defense, we know little about their genetic basis. Only a handful of studies have quantified heritable variation for nectar traits, primarily in controlled environments that minimize environmental variation. Most such studies have reported strong genetic influences, with heritabilities often >0.35. However, because nectar traits are often very responsive to environmental variation, even substantial amounts of genetic variation may be swamped out in the,field. Environmental variation deserves to be studied in its own right, including exploration of genotype X environment interaction for nectar traits . Most genetic studies of …


Aaas Lecture Series On Women In Science And Engineering, Maribel Vazquez Jun 2004

Aaas Lecture Series On Women In Science And Engineering, Maribel Vazquez

Publications and Research

The winning essay for a Travel Award from the American Association for the Advancement in Science Women Lecture Series.

http://ehrweb.aaas.org/womeninscience/essays/vazquez.htm


Evolution Of Morphological Integration. I. Functional Units Channel Stress-Induced Variation In Shrew Mandibles, Alexander V. Badyaev, Kerry R. Foresman Jun 2004

Evolution Of Morphological Integration. I. Functional Units Channel Stress-Induced Variation In Shrew Mandibles, Alexander V. Badyaev, Kerry R. Foresman

Biological Sciences Faculty Publications

Stress-induced deviations from normal development are often assumed to be random, yet their accumulation and expression can be influenced by patterns of morphological integration within an organism. We studied within-individual developmental variation ( fluctuating asymmetry) in the mandible of four shrew species raised under normal and extreme environments. Patterns of among-individual variation and fluctuating asymmetry were strongly concordant in traits that were involved in the attachment of the same muscles (i.e., functionally integrated traits), and fluctuating asymmetry was closely integrated among these traits, implying direct developmental interactions among traits involved in the same function. Stress-induced variation was largely confined to …


Homing Endonucleases Encoded By Germ Line-Limited Genes In Tetrahymena Thermophila Have Apetela2 Dna Binding Domains, Jeffrey D. Wuitschick, Paul R. Lindstrom, Alison E. Meyer, Kathleen M. Karrer Jun 2004

Homing Endonucleases Encoded By Germ Line-Limited Genes In Tetrahymena Thermophila Have Apetela2 Dna Binding Domains, Jeffrey D. Wuitschick, Paul R. Lindstrom, Alison E. Meyer, Kathleen M. Karrer

Biological Sciences Faculty Research and Publications

Three insertion elements were previously found in a family of germ line-limited mobile elements, the Tlr elements, in the ciliate Tetrahymena. Each of the insertions contains an open reading frame (ORF). Sequence analysis of the deduced proteins encoded by the elements suggests that they are homing endonucleases. The genes are designated TIE1-1, TIE2-1, and TIE3-1 for Tetrahymena insertion-homing endonuclease. The endonuclease motif occupies the amino terminal half of each TIE protein. The C-terminal regions of the proteins are similar to the APETELA2 DNA binding domain of plant transcription factors. The TIE1 and TIE3 elements belong to families of repeated sequences …


A New Species Of Callulina (Anura: Microhylidae) From The West Usambara Mountains, Tanzania, Rafael O. De Sá, Simon P. Loader, Alan Channing Jun 2004

A New Species Of Callulina (Anura: Microhylidae) From The West Usambara Mountains, Tanzania, Rafael O. De Sá, Simon P. Loader, Alan Channing

Biology Faculty Publications

The description of the species Callulina kreffti was based on specimens collected in the East Usambara Mountains of Tanzania. Successive collecting has shown this species to be widely distributed through the Eastern Arc Mountains. Advertisement calls from populations in the type locality of Callulina kreffti were compared with calls from populations in the West Usambara Mountains. Analysis of the calls suggested that these two populations of Callulina represent two separate taxa. Subsequent morphological and molecular investigations indicated that these two populations are distinct. Herein, we describe a new Callulina species on the basis of call, morphology and molecular sequences.


Development Of Web Tools For Nlx Simulation Software, Daniel Chai Siriphongs Jun 2004

Development Of Web Tools For Nlx Simulation Software, Daniel Chai Siriphongs

Loma Linda University Electronic Theses, Dissertations & Projects

Valuable mathematical equations have developed within biology and other sciences (physics, chemistry, etc.) that model various processes, but the complexity of the equations are not easily understood by students, scientists, and those with limited knowledge of the subject area. Simulation software used to visually explain a model is normally proprietary to the specific model equations and cannot be easily adapted to new models by non-programmers. Simulation software needs to be modular and based upon web technologies so that the software can be run on multiple platforms. The NLX simulation software is a group of Java-based objects that can be combined …


Diploid And Polyploid Cytotype Distribution In Melampodium Cinereum And M. Leucanthum (Asteraceae, Heliantheae), Tod F. Stuessy, Hanna Weiss-Schneeweiss, David J. Keil Jun 2004

Diploid And Polyploid Cytotype Distribution In Melampodium Cinereum And M. Leucanthum (Asteraceae, Heliantheae), Tod F. Stuessy, Hanna Weiss-Schneeweiss, David J. Keil

Biological Sciences

Previous chromosomal studies within Melampodium (Asteraceae, Heliantheae) of Mexico and Central America have documented chromosome numbers n = 9, 10, 11, 12, 18, 20, 23, 25 ± 1, 27, 30, and 33. Some species also have been shown to exhibit infra-and interpopulational polyploidy. The presence of cytotype mixtures is especially pronounced in the white-rayed complex, which occurs in the southwestern United States and adjacent Mexico. This group includes M. cinereum (n = 10 and 20), M. leucanthum (n = 10 and 20), and M. argophyllum (n = 30). Cytotype distribution has been newly analyzed in 415 plants from 152 populations …


A New Toad (Anura: Bufonidae) From Uruguay, Raúl Maneyro, Diego Arrieta, Rafael O. De Sá Jun 2004

A New Toad (Anura: Bufonidae) From Uruguay, Raúl Maneyro, Diego Arrieta, Rafael O. De Sá

Biology Faculty Publications

A new species of toad is described from small streams in the hills of Cuchilla de Haedo and Cuchilla Grande in northeastern Uruguay. Specimens of the new species were previously mistaken for Bufo arenarum; they differ from B.arenarum by having elongated parotoid glands and reddish-brown parotoid and cephalic crests. A discriminant analysis resulted in three groups corresponding to B. arenarum, Bufo rufus, and the specimens herein described as a new species.


A Biochemical Study Of Mucus Lysomzyme, Proteins And Plasma Thyroxine Of Atlanctic Salmon (Salmo Salar) During Smoltification, Maresa Fagan Jun 2004

A Biochemical Study Of Mucus Lysomzyme, Proteins And Plasma Thyroxine Of Atlanctic Salmon (Salmo Salar) During Smoltification, Maresa Fagan

Masters

Atlantic salmon prepare to migrate from fresh water to sea water during a phase of great physiological change known as smoltification. In the context of stock enhancement programmes and the conservation of Atlantic salmon stocks, the release of smolts from freshwater to sea is of major significance. Accordingly, this study set out to monitor some of the physiological and biochemical changes, which allow the Atlantic salmon to migrate from freshwater to seawater. Our research focused on skin mucus as a possible candidate for the development of a non invasive test and sought to elucidate biochemical or significant protein changes in …


Recovery Of Vegetation Following A Wildfire In A Barrier Island Grassland, Padre Island National Seashore, Texas, Robert I. Lonard, Frank W. Judd, Elizabeth H. Smith, Chenghai Yang Jun 2004

Recovery Of Vegetation Following A Wildfire In A Barrier Island Grassland, Padre Island National Seashore, Texas, Robert I. Lonard, Frank W. Judd, Elizabeth H. Smith, Chenghai Yang

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

Vegetation recovery following a wildfire in vegetated flats and secondary dunes of Padre Island National Seashore, Texas, was studied from January 2000 to January 2002. Species richness, diversity, evenness, abundance, and importance were evaluated. Species richness, diversity, and evenness were restored quickly in vegetated flats (51 days) and secondary dunes (71 days). The burned secondary dune site had the same dominant species as its non-burned counterpart from the beginning to the end of the study, but it took 106 days for the dominant species to be restored in the burned vegetated flats. No exotic species established in burned sites. Two …


Non-Parametric Algorithms For Evaluating Gene Expression In Cancer Using Dna Microarray Technology, Virginie Aris May 2004

Non-Parametric Algorithms For Evaluating Gene Expression In Cancer Using Dna Microarray Technology, Virginie Aris

Dissertations

Microarray technology has transformed the field of cancer biology by enabling the simultaneous evaluation of tens of thousands mRNA expression levels in a single experiment. This technology has been applied to medical science in order to find gene expression markers that cluster diseased and normal tissues, genes affected by treatments, and gene network interactions. All methods of microarray data analysis can be summarized as a study of differential gene expression. This study addresses three questions, 1) the roles of selectively expressed genes for the classification of cancer, 2) issues of accounting for both experimental and biological noise, and 3) issues …


Individual Cell Growth Rates Of Marine Bacteria, Measured By Bromodeoxyuridine Incorporation, Koji Hamasaki, Richard A. Long, Farooq Azam May 2004

Individual Cell Growth Rates Of Marine Bacteria, Measured By Bromodeoxyuridine Incorporation, Koji Hamasaki, Richard A. Long, Farooq Azam

Faculty Publications

We tested the application of 5-bromo-2’-deoxyuridine (BrdU), a thymidine analogue that becomes incorporated into DNA during growth, to measure growth rates of individual marine bacteria cells. Immunocytochemical detection of BrdU incorporation into bacterial DNA has the potential for single-cell-based growth measurement. Optimized procedure for immunocytochemistry was applicable to 14 marine heterotrophic bacterial isolates belonging to g-proteobacteria, α-proteobacteria, Cytophaga-Flavobacterium-Bacteroides (CFB) group and Gram-positive bacteria. The relationship between cell-specific fluorescence intensity and specific growth rate was linearly correlated among CFB group isolates, which indicated a potential of the method for quantitative measurement. Analysis of the detection limit indicated …


Uncoupling Conformational Change From Gtp Hydrolysis In A Heterotrimeric G Protein Alpha-Subunit, Celestine J. Thomas, Xinlin Du, Pilong Li, Ying Wang, Elliott M. Ross, Stephen R. Sprang May 2004

Uncoupling Conformational Change From Gtp Hydrolysis In A Heterotrimeric G Protein Alpha-Subunit, Celestine J. Thomas, Xinlin Du, Pilong Li, Ying Wang, Elliott M. Ross, Stephen R. Sprang

Biological Sciences Faculty Publications

Heterotrimeric G protein alpha (G alpha) subunits possess intrinsic GTPase activity that leads to functional deactivation with a rate constant of approximately 2 min(-1) at 30 degrees C. GTP hydrolysis causes conformational changes in three regions of G alpha, including Switch I and Switch II. Mutation of G202-->A in Switch II of G alpha(i1) accelerates the rates of both GTP hydrolysis and conformational change, which is measured by the loss of fluorescence from Trp-211 in Switch II. Mutation of K180-->P in Switch I increases the rate of conformational change but decreases the GTPase rate, which causes transient but …


Survey Of Anuran Populations Within Minnesota, Chris Thorman May 2004

Survey Of Anuran Populations Within Minnesota, Chris Thorman

Honors Capstones

Capstone submitted as a graduation requirement for the BSU Honors Program.


Pcr And 16s Rdna Sequencing For Identifying And Comparing Gram-Negative Bacteria, Molly Truax May 2004

Pcr And 16s Rdna Sequencing For Identifying And Comparing Gram-Negative Bacteria, Molly Truax

Honors Capstones

Capstone submitted as a graduation requirement for the BSU Honors Program.


Passive Stretch Inhibits Central Corelike Lesion Formation In The Soleus Muscles Of Hindlimb-Suspended Unloaded Rats, D. V. Baewer, Mark A. Hoffman, Janell Romatowski, J. L. W. Bain, Robert H. Fitts, Danny A. Riley May 2004

Passive Stretch Inhibits Central Corelike Lesion Formation In The Soleus Muscles Of Hindlimb-Suspended Unloaded Rats, D. V. Baewer, Mark A. Hoffman, Janell Romatowski, J. L. W. Bain, Robert H. Fitts, Danny A. Riley

Biological Sciences Faculty Research and Publications

Hindlimb suspension unloading (HSU) is a ground-based model simulating the effects of microgravity unloading on the musculoskeletal system. In this model, gravity causes the hind foot of the rat to drop, opening the front of the ankle to 90–105° plantar flexion at rest. As HSU proceeds, the normal weight-bearing angle of 30° dorsiflexion is achieved progressively less, and the contraction range of soleus is abbreviated. Our laboratory reported that 12 days of HSU caused central corelike lesions (CCLs) of myofibril breakdown (Riley DA, Slocum GR, Bain JL, Sedlak FR, Sowa TE, and Mellender JW. J Appl Physiol. 69: 58–66, 1990). …


Fiber Type And Temperature Dependence Of Inorganic Phosphate: Implications For Fatigue, Edward Patrick Debold, H. Dave, Robert H. Fitts May 2004

Fiber Type And Temperature Dependence Of Inorganic Phosphate: Implications For Fatigue, Edward Patrick Debold, H. Dave, Robert H. Fitts

Biological Sciences Faculty Research and Publications

Elevated levels of Pi are thought to cause a substantial proportion of the loss in muscular force and power output during fatigue from intense contractile activity. However, support for this hypothesis is based, in part, on data from skinned single fibers obtained at low temperatures (≤15°C). The effect of high (30 mM) Pi concentration on the contractile function of chemically skinned single fibers was examined at both low (15°C) and high (30°C) temperatures using fibers isolated from rat soleus (type I fibers) and gastrocnemius (type II fibers) muscles. Elevating Pi from 0 to 30 mM at saturating …


Does Seed Size Affect The Rate Of Germination And Early Seedling Growth In Hairy Vetch?, Joy Ekpo May 2004

Does Seed Size Affect The Rate Of Germination And Early Seedling Growth In Hairy Vetch?, Joy Ekpo

McCabe Thesis Collection

Size is an important characteristic of seed quality because larger seeds with larger volume contain more resources and are likely to exhibit greater vigor than smaller seeds (Ellis, 1992). In a range of plant species, seed size has been shown to affect germination rate, emergence rate, success of establishment, and growth (Black 1957; Bentley et al. 1980; Sanderson et al. 2002). Hairy vetch is an annual legume that is used for improvement of soil for pasture and to provide ground cover protecting against erosion (Duke 1981; Undersander 2002; Sattell et al 1988). Problems facing the establishment of hairy vetch are …


Genetic Analysis Of The Putative Streptolysin O Regulator From Streptococcus Pyogenes, Robert Tyrone Billingslea May 2004

Genetic Analysis Of The Putative Streptolysin O Regulator From Streptococcus Pyogenes, Robert Tyrone Billingslea

McCabe Thesis Collection

Group A streptococci (Streptococcus pyogenes) is one of the most frequent pathogens of humans. It is estimated that between 5-15% of normal individuals harbor the bacterium, usually in the upper respiratory tract, without signs of disease. S. pyogenes can initiate an active infection when defenses are compromised or when the organism is able to penetrate the host's defenses. When the bacteria invade vulnerable tissues, a variety of suppurative infections can occur. Acute S. pyogenes infection may be present as pharyngitis ("strep throat"), scarlet fever (rash), impetigo (infection of the superficial layers of the skin) or cellulitis (infection of the deep …


Moisture Potential Affects Rate Of Leaf Appearance In Cool Season Grasses, Nina Cherone Terrell May 2004

Moisture Potential Affects Rate Of Leaf Appearance In Cool Season Grasses, Nina Cherone Terrell

McCabe Thesis Collection

The rate of leaf appearance and onset of growth in cool season grasses may be influenced by soil moisture potential and exposure to below freezing temperatures. Levels of moisture potential and days exposed to freezing temperatures, which will restrict leaf appearance, are not well defined. The first part of this study was to determine the effects of different moisture potentials on the leaf appearance rates in two cool season grasses. Italian ryegrass (IRG) and tall wheat grass (TWG) were grown hydroponically at 4 moisture potentials in seed pouches in an incubator under a photoperiod of 13 hours light and 11 …