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Genetic Analysis Of Song Dialect Populations In Puget Sound White-Crowned Sparrows, Jill Soha, Douglas Nelson, Patricia Parker Jul 2004

Genetic Analysis Of Song Dialect Populations In Puget Sound White-Crowned Sparrows, Jill Soha, Douglas Nelson, Patricia Parker

Biology Department Faculty Works

The relationship between cultural variation and biological variation among natural populations has been the subject of both theoretical and empirical study. Zonotrichia leucophrys pugetensis is one of three subspecies of white-crowned sparrow known to form geographical song dialects. We investigated whether these dialects correspond to genetic differences among Z. l. pugetensis populations. We compared allele frequencies at four microsatellite loci in males from 11 sites spanning six dialects over the subspecies' range in Oregon and Washington. Cluster analysis and genotype assignment tests indicated no tendency for sample sites within dialect areas to be genetically more similar than are sites from …


Constraints On Adaptive Evolution: The Functional Trade-Off Between Reproduction And Fast-Start Swimming Performance In The Trinidadian Guppy (Poecilia Reticulata), Cameron K. Ghalambor, David N. Reznick, Jeffrey A. Walker Phd Jul 2004

Constraints On Adaptive Evolution: The Functional Trade-Off Between Reproduction And Fast-Start Swimming Performance In The Trinidadian Guppy (Poecilia Reticulata), Cameron K. Ghalambor, David N. Reznick, Jeffrey A. Walker Phd

Faculty Publications

The empirical study of natural selection reveals that adaptations often involve trade-offs between competing functions. Because natural selection acts on whole organisms rather than isolated traits, adaptive evolution may be constrained by the interaction between traits that are functionally integrated. Yet, few attempts have been made to characterize how and when such constraints are manifested or whether they limit the adaptive divergence of populations. Here we examine the consequences of adaptive life-history evolution on locomotor performance in the live-bearing guppy. In response to increased predation from piscivorous fish, Trinidadian guppies evolve an increased allocation of resources toward reproduction. These populations …


A Patch Hath Smaller Patches: Delineating Ecological Neighborhoods For Parasites, Derek Zelmer, John R. Seed Jul 2004

A Patch Hath Smaller Patches: Delineating Ecological Neighborhoods For Parasites, Derek Zelmer, John R. Seed

Faculty Publications

Use of the host individual as a boundary for parasite populations and communities provides an unambiguous spatial unit that is useful for pattern description, but this framework precludes consideration of the host landscape and within-host population dynamics. Recognizing host individuals as spatially and temporally complex landscapes requires modified concepts of parasite populations and communities. An outline of the currently accepted hierarchies of parasite populations and communities is provided on the basis of ecological neighborhoods that are delineated by discrete habitat patches or functional dynamics (or both), as opposed to host individuals. This parasite-based framework accommodates consideration of both within- and …


High Polymorphism In The K-Casein (Csn3) Gene From Wild And Domestic Caprine Species Revealed By Dna Sequencing, Oliver C. Jann, Eva-Maria Prinzenberg, Gordon Luikart, Ana Caroli, Georg Erhardt Jun 2004

High Polymorphism In The K-Casein (Csn3) Gene From Wild And Domestic Caprine Species Revealed By Dna Sequencing, Oliver C. Jann, Eva-Maria Prinzenberg, Gordon Luikart, Ana Caroli, Georg Erhardt

Biological Sciences Faculty Publications

We assessed polymorphisms in exon IV of the k-casein gene (CSN3) in ten different breeds of domestic goat (Capra hircus) from three continents and in three related wild caprine taxa (Capra ibex, Capra sibirica and Capra aegagrus). Thirty-five DNA samples were sequenced within a 558 bp fragment of exon IV. Nine polymorphic sites were identified in domestic goat, including four new polymorphisms. In addition to four previously described polymorphic positions, a total of 13 polymorphisms allowed the identification of 13 DNA variants, corresponding to 10 protein variants. Because of conflicting nomenclature of these variants, we propose …


Identification And Functional Analysis Of The Essential And Regulatory Light Chains Of The Only Type Ii Myosin Myo1p In Saccharomyces Cerevisiae, J. Luo, Elizabeth Ann Vallen, C. Dravis, S. E. Tcheperegine, B. Drees, E. Bi Jun 2004

Identification And Functional Analysis Of The Essential And Regulatory Light Chains Of The Only Type Ii Myosin Myo1p In Saccharomyces Cerevisiae, J. Luo, Elizabeth Ann Vallen, C. Dravis, S. E. Tcheperegine, B. Drees, E. Bi

Biology Faculty Works

Cytokinesis in Saccharomyces cerevisiae involves coordination between actomyosin ring contraction and septum formation and/or targeted membrane deposition. We show that Mlc1p, a light chain for Myo2p (type V myosin) and lqg1p (IQGAP), is the essential light chain for Myo1p, the only type 11 myosin in S. cerevisiae. However, disruption or reduction of Mlc1p-Myo1p interaction by deleting the Mlc1p binding site on Myo1p or by a point mutation in MLC1, mlc1-93, did not cause any obvious defect in cytokinesis. In contrast, a different point mutation, mlc1-11, displayed defects in cytokinesis and in interactions with Myo2p and lqg1p. These data suggest that …


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, …


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 …


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.


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 …


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 …


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 …


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 …


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.


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 …


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 …


Dynamics Of Pectoral Fin Rowing In A Fish With An Extreme Rowing Stroke: The Threespine Stickleback (Gasterosteus Aculeatus), Jeffrey A. Walker Phd May 2004

Dynamics Of Pectoral Fin Rowing In A Fish With An Extreme Rowing Stroke: The Threespine Stickleback (Gasterosteus Aculeatus), Jeffrey A. Walker Phd

Faculty Publications

The dynamics of pectoral fin rowing in the threespine stickleback are investigated by measuring the instantaneous force balance on freely swimming fish throughout the stroke cycle and comparing the measured forces with fin motions and an unsteady, blade-element model of pectoral fin propulsion. Both measured and modeled forces suggest that attached vortex and circulatory forces and not inertial (added mass) forces dominate the force balance. Peak forces occur at midstrokes. There is no evidence for large force peaks at the stroke transitions due to either rapid fin rotation (supination) or rapid fin closure against the body. The energetics of pectoral …


Population Size And Movements Of Spotted Salamanders At South Holston Dam, Sullivan County, Tennessee., Eric Alexander Smith May 2004

Population Size And Movements Of Spotted Salamanders At South Holston Dam, Sullivan County, Tennessee., Eric Alexander Smith

Electronic Theses and Dissertations

In the Southern Appalachians, there are growing concerns about Spotted Salamanders (Ambystoma maculatum) due to habitat destruction and the uncertain future of their forested riparian habitat. In this study, I establish baseline data of a population of Spotted Salamanders so future monitoring of this population can be performed. The study site is located in northeastern Tennessee, just east of the city of Bristol. It is a vernal pond at the Osceola Island Recreation Area one mile below the South Holston Dam on Holston View Dam road. A drift fence was established completely around the perimeter of the vernal …


Similarity Of Mammalian Body Size Across The Taxonomic Hierarchy And Across Space And Time, Felisa A. Smith, James H. Brown, John P. Haskell, S. Kathleen Lyons, John Alroy, Eric L. Charnov, Tamar Dayan, Brian J. Enquist, S.K. Morgan Ernest, Elizabeth A. Hadly, David Jablonski, Kate E. Jones, Dawn M. Kaufman, Pablo A. Marquet, Brian A. Maurer, Karl J. Niklas, Warren P. Porter, Kaustuv Roy, Bruce Tiffney, Michael R. Willig May 2004

Similarity Of Mammalian Body Size Across The Taxonomic Hierarchy And Across Space And Time, Felisa A. Smith, James H. Brown, John P. Haskell, S. Kathleen Lyons, John Alroy, Eric L. Charnov, Tamar Dayan, Brian J. Enquist, S.K. Morgan Ernest, Elizabeth A. Hadly, David Jablonski, Kate E. Jones, Dawn M. Kaufman, Pablo A. Marquet, Brian A. Maurer, Karl J. Niklas, Warren P. Porter, Kaustuv Roy, Bruce Tiffney, Michael R. Willig

Biology Faculty & Staff Publications

Although it is commonly assumed that closely related animals are similar in body size, the degree of similarity has not been examined across the taxonomic hierarchy. Moreover, little is known about the variation or consistency of body size patterns across geographic space or evolutionary time. Here, we draw from a data set of terrestrial, nonvolant mammals to quantify and compare patterns across the body size spectrum, the taxonomic hierarchy, continental space, and evolutionary time. We employ a variety of statistical techniques including "sib-sib" regression, phylogenetic autocorrelation, and nested ANOVA. We find an extremely high resemblance (heritability) of size among congeneric …


Rare, Threatened And Endangered Species Of Oregon (2004), James S. Kagan, Sue Vrilakas, Eleanor P. Gaines, Cliff Alton, Fern Mcarthur, Kuuipo Walsh, Eric Scheuering, John A. Christy, Jon Hak, Claudine Tobalske, Annie Weiland, Theresa Koloszar, Oregon Natural Heritage Information Center May 2004

Rare, Threatened And Endangered Species Of Oregon (2004), James S. Kagan, Sue Vrilakas, Eleanor P. Gaines, Cliff Alton, Fern Mcarthur, Kuuipo Walsh, Eric Scheuering, John A. Christy, Jon Hak, Claudine Tobalske, Annie Weiland, Theresa Koloszar, Oregon Natural Heritage Information Center

Institute for Natural Resources Publications

Extinction is a natural process. Today, however, plant and animal species are disappearing world-wide at an accelerated pace. Based on current trends, half of the species on earth will be extinct within the next 100 years. The major cause of this phenomenon is large-scale destruction of native habitats, which has increased since European settlement began in the mid 1800's - in Oregon and throughout the New World.

Once lost, a species can never be recovered, and there is no way of knowing how useful it may have been. We do know that human beings and many of their industries depend …


Natural History, Demography, And Home Range Characteristics Of A Southern California Population Of Phrynosoma Mcallii Inhabiting Atypical Habitat, Kirk Setser May 2004

Natural History, Demography, And Home Range Characteristics Of A Southern California Population Of Phrynosoma Mcallii Inhabiting Atypical Habitat, Kirk Setser

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Phrynosoma mcallii inhabiting a topographically complex, sparsely vegetated, "mudhill" terrain site in southern California in 1999 and 2000 had low mortality rates, and small clutch sizes compared to previous data from this species. Females likely produced a single clutch of eggs in each year. Although this population occurs near a heavily used OHV trail, I did not detect any mortality due to OHV use.

Lizards did not center home ranges on obvious habitat features. Lizards maintained smaller home ranges and exhibited greater range fidelity than did lizards at other sites in other years. Phrynosoma mcallii share many area-use characters with …


Host Shifts In Phytophagous Insects: A Mathematical Modeling Perspective, Meenakshi Venkataraman May 2004

Host Shifts In Phytophagous Insects: A Mathematical Modeling Perspective, Meenakshi Venkataraman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I explored changes in predator-prey system stability with the addition of spatial heterogeneity in prey density dependent mortality. The results indicated that this addition led to greater stability for all prey spatial distributions if prey was aggregated or loosely aggregated. These results indicated prey spatial distribution was critical to population stability. I next explored whether predator emigration under the above conditions would lead to a host shift. I used Chesson and Murdoch's templates of host density independent (HDI) aggregation and host density dependent (HDD) aggregation in predators as the basis for my metapopulation models. I varied prey density dependent mortality …


Estimating Metazoan Divergence Times With A Molecular Clock, Kevin J. Peterson, Jessica B. Lyons, Kristin S. Nowak, Carter M. Takacs, Matthew J. Wargo, Mark A. Mcpeek Apr 2004

Estimating Metazoan Divergence Times With A Molecular Clock, Kevin J. Peterson, Jessica B. Lyons, Kristin S. Nowak, Carter M. Takacs, Matthew J. Wargo, Mark A. Mcpeek

Dartmouth Scholarship

Accurately dating when the first bilaterally symmetrical animals arose is crucial to our understanding of early animal evolution. The earliest unequivocally bilaterian fossils are 555 million years old. In contrast, molecular-clock analyses calibrated by using the fossil record of vertebrates estimate that vertebrates split from dipterans (Drosophila) 900 million years ago (Ma). Nonetheless, comparative genomic analyses suggest that a significant rate difference exists between vertebrates and dipterans, because the percentage difference between the genomes of mosquito and fly is greater than between fish and mouse, even though the vertebrate divergence is almost twice that of the dipteran. Here we show …


Development Of A Tool To Facilitate Participation Of Maori In The Management Of Stream And River Health, Colin R. Townsend Apr 2004

Development Of A Tool To Facilitate Participation Of Maori In The Management Of Stream And River Health, Colin R. Townsend

Biological Sciences Faculty Research & Creative Works

A cultural health index (CHI) for streams was developed in a program of collaborative research involving members of Ngai Tahu (an iwi [tribe] within the South Island of New Zealand) and ecologists at Otago University. The aim was to provide a tool for effective participation of Maori in resource management decisions. Five cultural values are of central importance to the nature of the CHI: mauri (spiritual life force), mahinga kai (traditional resource harvesting), kaitiakitanga (guardianship obligation), ki uta ki tai (mountains-to-the-sea holistic philosophy), and wai taonga waters that are treasured). The CHI has three components. Forty-six stream sites in two …


Micrococcus Luteus - Survival In Amber, C. L. Greenblatt, J. Baum, B. Y. Klein, S. Nachshon, V. Koltunov, R. J. Cano Apr 2004

Micrococcus Luteus - Survival In Amber, C. L. Greenblatt, J. Baum, B. Y. Klein, S. Nachshon, V. Koltunov, R. J. Cano

Biological Sciences

A growing body of evidence now supports the isolation of microorganisms from ancient materials. However, questions about the stringency of extraction methods and the genetic relatedness of isolated organisms to their closest living relatives continue to challenge the authenticity of these ancient life forms. Previous studies have successfully isolated a number of spore-forming bacteria from organic and inorganic deposits of considerable age whose survival is explained by their ability to enter suspended animation for extended periods of time. However, despite a number of putative reports, the isolation of non-spore-forming bacteria and an explanation for their survival have remained enigmatic. Here …


Seasonal Dynamics Of Shallow-Hyporheic-Zone Microbial Community Structure Along A Heavy-Metal Contamination Gradient, Kevin P. Feris, Philip W. Ramsey, Chris Frazar, Matthias Rillig, Johnnie N. Moore, William E. Holben Apr 2004

Seasonal Dynamics Of Shallow-Hyporheic-Zone Microbial Community Structure Along A Heavy-Metal Contamination Gradient, Kevin P. Feris, Philip W. Ramsey, Chris Frazar, Matthias Rillig, Johnnie N. Moore, William E. Holben

Biological Sciences Faculty Publications

Heavy metals contaminate numerous freshwater streams and rivers worldwide. Previous work by this group demonstrated a relationship between the structure of hyporheic microbial communities and the fluvial deposition of heavy metals along a contamination gradient during the fall season. Seasonal variation has been documented in microbial communities in numerous terrestrial and aquatic environments, including the hyporheic zone. The current study was designed to assess whether relationships between hyporheic microbial community structure and heavy-metal contamination vary seasonally by monitoring community structure along a heavy-metal contamination gradient for more than a year. No relationship between total bacterial abundance and heavy metals was …


Gc Fractionation Enhances Microbial Community Diversity Assessment And Detection Of Minority Populations Of Bacteria By Denaturing Gradient Gel Electrophoresis, William Holben, Keving P. Feris, Anu Kettunen, Juha H. A. Apajalahti Apr 2004

Gc Fractionation Enhances Microbial Community Diversity Assessment And Detection Of Minority Populations Of Bacteria By Denaturing Gradient Gel Electrophoresis, William Holben, Keving P. Feris, Anu Kettunen, Juha H. A. Apajalahti

Biological Sciences Faculty Publications

Effectively and accurately assessing total microbial community diversity is one of the primary challenges in modern microbial ecology. This is particularly true with regard to the detection and characterization of unculturable populations and those present only in low abundance. We report a novel strategy, GC fractionation combined with denaturing gradient gel electrophoresis (GC-DGGE), which combines mechanistically different community analysis approaches to enhance assessment of microbial community diversity and detection of minority populations of microbes. This approach employs GC fractionation as an initial step to reduce the complexity of the community in each fraction. This reduced complexity facilitates subsequent detection of …


Fisheries Occasional Publication No. 6 - Anglers Guide To Assessing Reproductive Stage In Fish, Kim Smith, Mike Mackie, Department Of Fisheries Western Australia Apr 2004

Fisheries Occasional Publication No. 6 - Anglers Guide To Assessing Reproductive Stage In Fish, Kim Smith, Mike Mackie, Department Of Fisheries Western Australia

Fisheries Occasional Publications

What is a gonad?

"Gonad" is a general term for a reproductive organ, and is used to describe both ovaries and testes. In male and female fish, the gonad is an elongated organ lying along the upper wall of the gut cavity (i.e. running immediately under the vertebral column). The gonad gonad has 2 lobes. Both lobes are attached to the body near the anus and extend forward inside the gut cavity.

As fish gonads ripen, they become larger, heavier and change colour. Immature and undeveloped adult gonads are very small, strap-like in shape, pinkish in colour and translucent (i.e. …


The Distribution Of Fox Squirrel (Sciurus Niger) Leaf Nests Within Forest Fragments In Central Indiana, Carmen M. Salsbury, Rebecca W. Dolan, Emily B. Pentzer Apr 2004

The Distribution Of Fox Squirrel (Sciurus Niger) Leaf Nests Within Forest Fragments In Central Indiana, Carmen M. Salsbury, Rebecca W. Dolan, Emily B. Pentzer

Scholarship and Professional Work - LAS

We examined the abundance and placement of leaf nests by fox squirrels in six urban woodlots in central Indiana ranging in size from 1.06 to 8.28 ha. Four of the woodlots were disturbed, or subject to extensive human impact, whereas the remaining two were nature preserves. We counted all leaf nests present in each woodlot and recorded nest tree characteristics. We then conducted a quantitative vegetation analysis of trees present and estimated percentages of herbaceous and shrub cover along a minimum of two 100 m transects at each site. Fox squirrels showed a preference to build nests in certain species …