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Articles 121 - 150 of 3598
Full-Text Articles in Life Sciences
Intsormil, Elvis A. Heinrichs
Intsormil, Elvis A. Heinrichs
INTSORMIL Scientific Publications
The Sorghum, Millet and Other Grains CRSP (INTSORMIL) is funded by the United States Agency for International Development and collaborating organizations in the U.S and in host countries. The Global INTSORMIL program involves 17 U.S. scientists at six universities and the USDA and 23 host country national research programs. The INTSORMIL mission is to use collaborative research to overcome constraints to sorghum, millet and other grains (fonio, tef and finger millet) production and utilization for the mutual benefit of agriculture in the U.S. and developing countries.
The focus is on increasing food security and promoting market development of sorghum and …
Communicator, Dec. 2007, San Jose State University, Department Of Kinesiology
Communicator, Dec. 2007, San Jose State University, Department Of Kinesiology
Communicator (Kinesiology)
Volume 20, Issue 2
Center For Grassland Studies Newsletter, Winter 2007, Volume 13, No. 1
Center For Grassland Studies Newsletter, Winter 2007, Volume 13, No. 1
Center for Grassland Studies: Newsletters
Contents • Restoration of Salt Cedar Infestations • From the Director • Patch-burn Grazing: Benefits for Both Wildlife Habitat and Livestock Performance by Chris Helzer • CGS Associates • Soil Physical Characteristics of Aging Golf Greens by Roch Gaussoin • Jim Gerrish to Speak at 2007 Nebraska Grazing Conference
Age-Structured Population Model With Cannibalism, Mmohammed El-Doma
Age-Structured Population Model With Cannibalism, Mmohammed El-Doma
Applications and Applied Mathematics: An International Journal (AAM)
An age-structured population model with cannibalism is investigated. We determine the steady states and study the local asymptotic stability as well as the global stability. The results in this paper generalize previous results.
Stability Analysis For The Gurtin-Maccamy’S Age-Structured Population Dynamics Model, Mohammed El-Doma
Stability Analysis For The Gurtin-Maccamy’S Age-Structured Population Dynamics Model, Mohammed El-Doma
Applications and Applied Mathematics: An International Journal (AAM)
The stability of the Gurtin-MacCamy’s age-structured population dynamics model is investigated. We determine the steady states and study their stability. The results in this paper generalize previous results.
2005 Coastal Municipal Stormwater Infrastructure Mapping Project, Jeffrey Marcoux
2005 Coastal Municipal Stormwater Infrastructure Mapping Project, Jeffrey Marcoux
PREP Reports & Publications
The New Hampshire Department of Environmental Services (DES) received funds in 2005 from the New Hampshire Estuaries Project (NHEP) to provide assistance to coastal communities to develop storm sewer infrastructure maps. This final report describes the grant projects completed in Rye and Seabrook.
NHEP chose to fund stormwater infrastructure mapping projects for a number of reasons. Primarily, this grant was established in order to fulfill one of the water quality action plans identified in the NHEP Management Plan. In addition, the Coastal/Piscataqua watershed has been identified by DES as a priority watershed in need of restoration. Updated and comprehensive maps …
Phylogenetic Relationships In Tribe Cariceae (Cyperaceae) Based On Nested Analyses Of Four Molecular Data Sets, Marcia J. Waterway, Julian R. Starr
Phylogenetic Relationships In Tribe Cariceae (Cyperaceae) Based On Nested Analyses Of Four Molecular Data Sets, Marcia J. Waterway, Julian R. Starr
Aliso: A Journal of Systematic and Floristic Botany
Phylogenetic reconstruction for Carex and relatives in tribe Cariceae is complicated by species richness and nearly cosmopolitan distribution. In this investigation, our main objective was to estimate evolutionary relationships in tribe Cariceae using DNA sequence data from two spacer regions in nuclear ribosomal genes (ITS and ETS-1f) combined with noncoding chloroplast DNA (trnL intron, trnL–trnF intergenic spacer, and trnE–trnD intergenic spacers). Parsimony analyses of separate and combined data and Bayesian analysis of the combined data matrix revealed strong support for monophyly of tribe Cariceae and for monophyly of two major lineages, one …
An Electronic World Grass Flora, Steve Renvoize, Derek Clayton, Tom Cope, Helen Williamson
An Electronic World Grass Flora, Steve Renvoize, Derek Clayton, Tom Cope, Helen Williamson
Aliso: A Journal of Systematic and Floristic Botany
The development of an electronic world grass flora database is described in which data for 1090 morphological characters gathered for 11,000 species in 700 genera organized according to accepted names. This descriptive information is linked to a synonym database of 60,000 names. Authors, literature references, and the status of each name are also recorded in the database along with geographical distribution and type information. The list of accepted species is linked to a global herbarium of 350,000 specimens at Kew arranged in a phylogenetic sequence at the generic and species levels and according to broad phytogeographic divisions. From the database, …
Classification And Biogeography Of New World Grasses: Anomochlooideae, Pharoideae, Ehrhartoideae, And Bambusoideae, Emmet J. Judziewicz, Lynn G. Clark
Classification And Biogeography Of New World Grasses: Anomochlooideae, Pharoideae, Ehrhartoideae, And Bambusoideae, Emmet J. Judziewicz, Lynn G. Clark
Aliso: A Journal of Systematic and Floristic Botany
Molecular data support Anomochlooideae and Pharoideae as the two most basal extant clades within Poaceae. Anomochlooideae are endemic to the New World and have two tribes and two genera including the widespread Streptochaeteae (3–4 spp.) and the critically endangered Anomochloeae (1 sp.) of coastal Bahia, Brazil. Pharoideae are pantropical with one tribe, three genera, and 14 species; all eight species of Pharus occur only in the New World. Bambusoideae and Ehrhartoideae are sister groups and together form a clade sister to Pooideae, although support for this set of relationships is low. Ehrhartoideae are a worldwide subfamily represented in the New …
Hydrological Parameters For New Hampshire's Estuaries, Phil Trowbridge
Hydrological Parameters For New Hampshire's Estuaries, Phil Trowbridge
PREP Reports & Publications
The New Hampshire Estuaries Project (NHEP) is part of the U.S. Environmental Protection Agency’s National Estuary Program which is a joint local/state/federal program established under Section 320 of the Clean Water Act with the goal of protecting and enhancing nationally significant estuaries. The NHEP’s Comprehensive Conservation and Management Plan for New Hampshire’s estuaries was completed in 2000 and implementation is ongoing. The Management Plan outlines key issues related to management of New Hampshire’s estuaries and proposes strategies that are expected to collectively preserve and protect the state’s estuarine resources. The coastal watershed for the NHEP drains into two major estuary …
A General Boosting Method And Its Application To Learning Ranking Functions For Web Search, Zhaohui Zheng, Hongyuan Zha, Tong Zhang, Olivier Chapelle, Keke Chen, Gordon Sun
A General Boosting Method And Its Application To Learning Ranking Functions For Web Search, Zhaohui Zheng, Hongyuan Zha, Tong Zhang, Olivier Chapelle, Keke Chen, Gordon Sun
Kno.e.sis Publications
We present a general boosting method extending functional gradient boosting to optimize complex loss functions that are encountered in many machine learning problems. Our approach is based on optimization of quadratic upper bounds of the loss functions which allows us to present a rigorous convergence analysis of the algorithm. More importantly, this general framework enables us to use a standard regression base learner such as decision trees for fitting any loss function. We illustrate an application of the proposed method in learning ranking functions for Web search by combining both preference data and labeled data for training. We present experimental …
Grevillea Robusta A. Cunningham Ex R. Br., J. Richard Abbott
Grevillea Robusta A. Cunningham Ex R. Br., J. Richard Abbott
Specimens by Name
No abstract provided.
Systematic Reviews Of Animal Experiments Demonstrate Poor Human Clinical And Toxicological Utility, Andrew Knight
Systematic Reviews Of Animal Experiments Demonstrate Poor Human Clinical And Toxicological Utility, Andrew Knight
Experimentation Collection
The assumption that animal models are reasonably predictive of human outcomes provides the basis for their widespread use in toxicity testing and in biomedical research aimed at developing cures for human diseases. To investigate the validity of this assumption, the comprehensive Scopus biomedical bibliographic databases were searched for published systematic reviews of the human clinical or toxicological utility of animal experiments. In 20 reviews in which clinical utility was examined, the authors concluded that animal models were either significantly useful in contributing to the development of clinical interventions, or were substantially consistent with clinical outcomes, in only two cases, one …
Heritable And Experiential Effects On Boldness In A Tropical Poeciliid, Culum Brown, Fiona Burgess, Victoria Braithwaite
Heritable And Experiential Effects On Boldness In A Tropical Poeciliid, Culum Brown, Fiona Burgess, Victoria Braithwaite
Sentience Collection
Consistent differences in human behaviour are often explained with reference to personality traits. Recent evidence suggests that similar traits are widespread across the entire animal kingdom and that they may have substantial fitness consequences. One of the major components of personality is the shyness–boldness continuum. Little is known about the relative contributions of genes and the environment in the development of boldness in wild animal populations. Here, we bred wild-caught fish (Brachyraphis episcopi) collected from regions of highand low-predation pressure, reared their offspring in the laboratory under varying conditions and tested boldness utilising an open-field paradigm. First-generation laboratory-reared fish showed …
Correlation Between Boldness And Body Mass In Natural Populations Of The Poeciliid Brachyrhaphis Episcopi, C. Brown, F. Jones, V. Braithwaite
Correlation Between Boldness And Body Mass In Natural Populations Of The Poeciliid Brachyrhaphis Episcopi, C. Brown, F. Jones, V. Braithwaite
Sentience Collection
The boldness of individual Brachyrhaphis episcopi, collected from regions of high and low predation, was investigated using two independent assays: (1) the time to emerge from cover and (2) the propensity to leave shoal mates and investigate a novel object. A strong correlation between the two assays was revealed such that fish that emerged from shelter sooner were also more likely to approach a novel object. This is indicative of a boldness personality axis acting across both behavioural contexts. Fish from high-predation areas were bolder than those from low-predation areas and males were bolder than females. A significant correlation between …
Lichens Of Pine Hill, A Peridotite Outcrop In Eastern North America, Tanner B. Harris, Fred C. Olday, Nishanta Rajakaruna
Lichens Of Pine Hill, A Peridotite Outcrop In Eastern North America, Tanner B. Harris, Fred C. Olday, Nishanta Rajakaruna
Biological Sciences
Despite a large body of work on the serpentine-substrate effect on vascular plants, little work has been undertaken to describe lichen communities growing on serpentine soils derived from peridotite and other ultramafic rocks. Most such work has been conducted in Europe and western North America. Only one study to date has examined the lichen flora of an ultramafic outcrop in eastern North America. The current paper examines the lichen flora of a peridotite outcrop from Deer Isle, Hancock County, Maine, U.S.A. The lichen flora is presented along with relevant ecological and geochemical data. Sixty-three species were found, comprising 35 genera. …
Phylogenetic Relationships Of The Decumbentes Group Of Paspalum, Thrasya, And Thrasyopsis (Poaceae: Panicoideae: Paniceae), Silvia S. Denham, Fernando O. Zuloaga
Phylogenetic Relationships Of The Decumbentes Group Of Paspalum, Thrasya, And Thrasyopsis (Poaceae: Panicoideae: Paniceae), Silvia S. Denham, Fernando O. Zuloaga
Aliso: A Journal of Systematic and Floristic Botany
Paspalum (Poaceae: Panicoideae: Paniceae) includes 330 species distributed mainly in tropical and subtropical regions of America. Due to the large number of species and convergence in many characters, an adequate infrageneric classification is still needed. Studies on Paniceae based on molecular and morphological data have suggested that Paspalum is paraphyletic, including the genus Thrasya, but none of these analyses have included a representative sample of these two genera. In this study, phylogenetic relationships among the informal group Decumbentes of Paspalum, plus subgenera and other informal groups, and the genera Thrasya and Thrasyopsis were estimated. A cladistic analysis under …
The Jeweled Armor Of Tillandsia—Multifaceted Or Elongated Trichomes Provide Photoprotection, Simon Pierce
The Jeweled Armor Of Tillandsia—Multifaceted Or Elongated Trichomes Provide Photoprotection, Simon Pierce
Aliso: A Journal of Systematic and Floristic Botany
Foliar trichomes of gray-leaved Tillandsioideae (Bromeliaceae) are highly reflective, suggesting a role in protecting the leaf against direct sunlight in exposed niches. The performance of photosystem II, as denoted by the chlorophyll fluorescence characteristic Fv /Fm , was determined for seven Tillandsia species and Vriesea barclayana that were exposed to excessive light, with trichomes either present or removed. Additionally, trichome structure and interaction with light was recorded using extended depth-of-field photomicrography, and reflectance quantified using a novel photographic technique. Trichomes of mesomorphic Type IV life forms (T. cryptantha, T. cyanea) and of the intermediate life …
Chromosome Evolution In Cyperales, Eric H. Roalson, Andrew G. Mccubbin, Richard Whitkus
Chromosome Evolution In Cyperales, Eric H. Roalson, Andrew G. Mccubbin, Richard Whitkus
Aliso: A Journal of Systematic and Floristic Botany
Karyotypic evolution is a prominent feature in the diversification of many plants and animals, yet the role that chromosomal changes play in the process of diversification is still debated. At the diploid level, chromosome fission and/or fusion are necessary components of chromosomal structural change associated with diversification. Yet the genomic features required for these events remain unknown. Here we present an overview of what is known about genomic structure in Cyperales, with particular focus on the current level of understanding of chromosome number and genome size and their impact in a phylogenetic context. We outline ongoing projects exploring genomic structure …
Phylogeny Of Cyperaceae Based On Dna Sequence Data–A New Rbcl Analysis, David A. Simpson, A. Muthama Muasya, Marccus V. Alves, Jeremy J. Bruhl, Sandra Dhooge, Mark W. Chase, Carol A. Furness, Kioumars Ghamkhar, Paul Goetghebeur, Trevor R. Hodkinson, Adam D. Marchant, Anton A. Reznicek, Roland Nieuwborg, Eric H. Roalson, Erik Smets, Julian R. Starr, William W. Thomas, Karen L. Wilson, Xiufu Zhang
Phylogeny Of Cyperaceae Based On Dna Sequence Data–A New Rbcl Analysis, David A. Simpson, A. Muthama Muasya, Marccus V. Alves, Jeremy J. Bruhl, Sandra Dhooge, Mark W. Chase, Carol A. Furness, Kioumars Ghamkhar, Paul Goetghebeur, Trevor R. Hodkinson, Adam D. Marchant, Anton A. Reznicek, Roland Nieuwborg, Eric H. Roalson, Erik Smets, Julian R. Starr, William W. Thomas, Karen L. Wilson, Xiufu Zhang
Aliso: A Journal of Systematic and Floristic Botany
Since the Monocots II meeting in 1998, significant new data have been published that enhance our systematic knowledge of Cyperaceae. Phylogenetic studies in the family have also progressed steadily. For this study, a parsimony analysis was carried out using all rbcL sequences currently available for Cyperaceae, including data for two new genera. One of the four subfamilies (Caricoideae) and seven of the 14 tribes (Bisboeckelereae, Cariceae, Cryptangieae, Dulichieae, Eleocharideae, Sclerieae, Trilepideae) are monophyletic. Subfamily Mapanioideae and tribe Chrysitricheae are monophyletic if, as the evidence suggests, Hellmuthia is considered a member of Cypereae. Some other features of our analysis include: …
Phylogenetic Implications Of A Unique 5.8s Nrdna Insertion In Cyperaceae, Julian R. Starr, Geneviève Gravel, Anne Bruneau, A. Muthama Muasya
Phylogenetic Implications Of A Unique 5.8s Nrdna Insertion In Cyperaceae, Julian R. Starr, Geneviève Gravel, Anne Bruneau, A. Muthama Muasya
Aliso: A Journal of Systematic and Floristic Botany
The purpose of this study was to assess the phylogenetic utility of a large insertion (3 bp) in the 5.8S gene of nuclear ribosomal DNA (nrDNA) in Cyperaceae and selected Juncaceae. This was done by reconstructing the character evolution of the insertion on a phylogeny derived from rbcL sequences. Results suggest that the insertion was gained once at the base of Cyperaceae followed by multiple losses in its most-derived taxa. Despite several homoplastic losses (CI = 0.20), the pattern of insertion loss (RI = 0.88), and base pair variation within the insertion were useful for defining sedge clades at …
Chromosome Number Changes Associated With Speciation In Sedges: A Phylogenetic Study In Carex Section Ovales (Cyperaceae) Using Aflp Data, Andrew L. Hipp, Paul E. Rothrock, Anton A. Reznicek, Paul E. Berry
Chromosome Number Changes Associated With Speciation In Sedges: A Phylogenetic Study In Carex Section Ovales (Cyperaceae) Using Aflp Data, Andrew L. Hipp, Paul E. Rothrock, Anton A. Reznicek, Paul E. Berry
Aliso: A Journal of Systematic and Floristic Botany
Phylogenetic analysis of amplified fragment length polymorphisms (AFLP) was used to infer patterns of morphologic and chromosomal evolution in an eastern North American group of sedges (ENA clade I of Carex sect. Ovales). Distance analyses of AFLP data recover a tree that is topologically congruent with previous phylogenetic estimates based on nuclear ribosomal DNA (nrDNA) sequences and provide support for four species groups within ENA clade I. A maximum likelihood method designed for analysis of restriction site data is used to evaluate the strength of support for alternative topologies. While there is little support for the precise placement of …
Plasticity Of Chasmogamous And Cleistogamous Reproductive Allocation In Grasses, Gregory P. Cheplick
Plasticity Of Chasmogamous And Cleistogamous Reproductive Allocation In Grasses, Gregory P. Cheplick
Aliso: A Journal of Systematic and Floristic Botany
Cleistogamy is more common in grasses than in any other angiosperm family. Both self-fertilized cleistogamous (CL) spikelets and open-pollinated chasmogamous (CH) spikelets are typically produced. Relative allocation to CL and CH varies among species and populations, and is influenced by ontogeny and environment. The balance between reproductive modes can be expressed as a CH/CL ratio. This ratio is very plastic, and stressful conditions can result in values Amphicarpum purshii, an annual with subterranean CL spikelets, CH/CL declined as density increased because CH decreased more than CL as size was reduced by intraspecific competition. In the shade-tolerant annual Microstegium vimineum, …
Phenotypic Plasticity May Facilitate Invasion By Aegilops Triuncialis, Andrew R. Dyer
Phenotypic Plasticity May Facilitate Invasion By Aegilops Triuncialis, Andrew R. Dyer
Aliso: A Journal of Systematic and Floristic Botany
One great obstacle to understanding the invasion of nonnative species into native ecosystems is the lack of information on the population biology of the invading species. In particular, morphological and physiological adaptations and potential for phenotypic plasticity will strongly influence a species’ ability to persist and spread in newly invaded ecosystems. Phenotypic plasticity can buffer populations from selection thereby allowing them to survive the establishment phase of the invasion. The annual grass Aegilops triuncialis (Poaceae, Triticeae) has become highly invasive in California (USA) and provides an opportunity to investigate the importance of phenotypic plasticity to persistence and spread in new …
A Systematic Approach To Subtribe Loliinae (Poaceae: Pooideae) Based On Phylogenetic Evidence, Pilar Catalán, Pedro Torrecilla, José A. López-Rodríguez, Jochen Müller, Clive A. Stace
A Systematic Approach To Subtribe Loliinae (Poaceae: Pooideae) Based On Phylogenetic Evidence, Pilar Catalán, Pedro Torrecilla, José A. López-Rodríguez, Jochen Müller, Clive A. Stace
Aliso: A Journal of Systematic and Floristic Botany
Loliinae (Poaceae, Pooideae) encompass a large group of genera closely related to Festuca, the largest genus in the subtribe, which as traditionally circumscribed has been shown to be highly paraphyletic. In this investigation we combined molecular and morphological data representing 20 genera of Loliinae and closely related subtribes. Combined analysis of nucleotide sequences from the nuclear ITS and chloroplast trnL–F regions and structural characters recovered a consensus topology that shows Loliinae to be monophyletic and possessing two main clades—the fine-leaved Festuca clade that includes Ctenopsis, Micropyrum, Narduroides, Psilurus, Vulpia, and Wangenheimia, and …
Phylogeny Of Poa (Poaceae) Based On Trnt–Trnf Sequence Data: Major Clades And Basal Relationships, Lynn J. Gillespie, Annie Archambault, Robert J. Soreng
Phylogeny Of Poa (Poaceae) Based On Trnt–Trnf Sequence Data: Major Clades And Basal Relationships, Lynn J. Gillespie, Annie Archambault, Robert J. Soreng
Aliso: A Journal of Systematic and Floristic Botany
Poa, the largest genus of grasses (Poaceae) with over 500 species, occurs throughout temperate and boreal regions in both hemispheres. A phylogenetic study of Poa based on trnT–trnF chloroplast DNA sequence data is presented focusing on basal relationships, major clades, generic boundaries, and placement of putatively closely related genera. Results support the monophyly of the main lineage of Poa if subgen. Andinae is excluded and Anthochloa, Austrofestuca, Dissanthelium (at least in part), and Eremopoa are included. The main Poa clade and subgen. Andinae resolve within a strongly supported Poinae–Alopecurinae–Miliinae clade (PAM). The subdivision of …
Variability Of Bluegrass (Poa) In Siberia, Marina V. Olonova
Variability Of Bluegrass (Poa) In Siberia, Marina V. Olonova
Aliso: A Journal of Systematic and Floristic Botany
Siberian bluegrass (Poa) includes a number of polymorphic species such as P. arctica s.l., P. nemoralis s.l., P. palustris s.l., P. pratensis s.l., P. sibirica s.l., and P. smirnovii s.l., plus numerous hybrids and purported derivatives (e.g., P. attenuata s.l., P. glauca s.l., P. urssulensis s.l.). In Siberia Poa is represented by morphologically isolated species and hybrid-apomictic complexes, including both distinct species and taxonomic groups of obscure rank. Section Stenopoa is especially rich in these complexes. Most of the key morphological characters used in the taxonomy of bluegrass vary as much within populations as among populations and thus …
Phylogenetics Of Andropogoneae (Poaceae: Panicoideae) Based On Nuclear Ribosomal Internal Transcribed Spacer And Chloroplast Trnl–F Sequences, Elizabeth M. Skendzic, J. Travis Columbus, Rosa Cerros-Tlatilpa
Phylogenetics Of Andropogoneae (Poaceae: Panicoideae) Based On Nuclear Ribosomal Internal Transcribed Spacer And Chloroplast Trnl–F Sequences, Elizabeth M. Skendzic, J. Travis Columbus, Rosa Cerros-Tlatilpa
Aliso: A Journal of Systematic and Floristic Botany
Phylogenetic relationships among 85 species representing 35 genera in the grass tribe Andropogoneae were estimated from maximum parsimony and Bayesian analyses of nuclear ITS and chloroplast trnL–F DNA sequences. Ten of the 11 subtribes recognized by Clayton and Renvoize (1986) were sampled. Independent analyses of ITS and trnL–F yielded mostly congruent, though not well resolved, topologies. Arundinella is sister to Andropogoneae in the trnL–F phylogeny and is nested within the tribe in the ITS and combined data trees. Tristachya is sister to Andropogoneae + Arundinella in the ITS phylogeny. Four clades are common to the ITS and …
Classification And Biogeography Of New World Grasses: Chloridoideae, Paul M. Peterson, J. Travis Columbus, Susan J. Pennington
Classification And Biogeography Of New World Grasses: Chloridoideae, Paul M. Peterson, J. Travis Columbus, Susan J. Pennington
Aliso: A Journal of Systematic and Floristic Botany
Subfamily Chloridoideae (Poaceae) in the New World includes 72 genera (61 native, 11 introduced), 678 species (607 native), and, including intraspecific taxa, 817 total taxa. The five largest genera are Muhlenbergia (147 species), Eragrostis (111), Sporobolus (76), Bouteloua (57), and Chloris (35). Three tribes are recognized in this study: Cynodonteae, Eragrostideae, and Zoysieae, with ten, three, and two subtribes, respectively. Cynodonteae, the largest tribe, comprise 58 genera and 451 species (67% of all New World chloridoids), including 25 genera (98 species, 22% of all New World Cynodonteae) with unknown affinities (incertae sedis). In Mexico, the USA, and Canada there are …
Diatom Species Composition And Ecology Of The Animas River Watershed, Colorado, Usa, Gerald V. Sgro, John B. Poole, Jeffrey R. Johansen
Diatom Species Composition And Ecology Of The Animas River Watershed, Colorado, Usa, Gerald V. Sgro, John B. Poole, Jeffrey R. Johansen
Biology
The diatom flora of selected sites in the Animas River Watershed, San Juan County, Colorado, was studied. Eighty diatom taxa were identified from 10 sites: 8 sites on the Animas River and 1 site each on the Cement and Cascade tributaries. The sample diatom abundance was dominated by Achnanthidium minutissimum, Encyonema silesiacum, Aulacoseira distans, Hannaea arcus, and Diatoma mesodon. The presence of teratologic specimens of Fragilaria and Achnanthidium in the samples indicated the possibility of metals contamination. Diatom diversity was low and Lange-Bertalot pollution index scores indicated little organic pollution evidenced from diatom composition. There was evidence that diatom composition …