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North Logan, UT, United States

Manning R.W.,107 LBJ Cove | Heaney M.R.,BIO WEST Inc. | Sagot M.,Texas Tech University | Baker R.J.,Texas Tech University
Southwestern Naturalist | Year: 2014

We review the known records of desert shrews from Nevada and report the results of genetic analyses of a specimen from Ash Meadows National Wildlife Refuge, Nye County, Nevada, which help clarify the evolutionary relationships of the genus Notiosorex from southwestern United States. Source

Tippery N.P.,University of Wisconsin - Whitewater | Schilling E.E.,University of Tennessee at Knoxville | Panero J.L.,University of Texas at Austin | Les D.H.,University of Connecticut | And 2 more authors.
Systematic Botany | Year: 2014

Plants that have adapted to grow as submersed aquatics are relatively rare among angiosperms, yet they represent a convergent strategy that has evolved in many groups. Asteraceae tribe Eupatorieae include a number of obligate wetland species, but only three genera (Gymnocoronis, Sclerolepis, and Shinnersia) routinely grow submersed. We conducted a molecular phylogenetic study of Eupatorieae to assess the relationships among aquatic genera and to infer the evolutionary history of the submersed aquatic habit. Two major clades were identified in Eupatorieae, corresponding to base chromosome numbers of x = 10 or fewer, and x = 11 or greater. We determined that submersed aquatics evolved independently in two subtribes, Adenostemmatinae (Gymnocoronis; x = 10) and Trichocoroninae (Sclerolepis and Shinnersia; x = 15), each belonging to a separate major clade, and that the aquatic lineages evolved in allopatry. Sparse taxon sampling precluded a firm assessment of ancestral states, although two widespread genera, Adenostemma and Mikania, were implicated as likely relatives of the aquatic lineages. Our data also support the continued recognition of Shinnersia and Trichocoronis, which occasionally have been considered synonymous, as distinct genera. © 2014 by the American Society of Plant Taxonomists. Source

Opdyke D.R.,Anchor QEA LLC | Oborny E.L.,BIO WEST Inc. | Vaugh S.K.,HDR | Mayes K.B.,Texas Parks and Wildlife Department
Hydrological Sciences Journal | Year: 2014

In 2007, the Texas legislature created a program to identify environmental flow standards statewide through the coordinated efforts of scientific and stakeholder groups and rulemaking by the Texas Commission on Environmental Quality. To aid in this task, a Hydrology-based Environmental Flow Regime (HEFR) method was developed that combines a suite of user-customizable hydrologic statistics with an implementation framework. Following the concepts of the Natural Flow Paradigm, the methodology includes the separation of a long-term hydrograph into key flow components (e.g. subsistence, base, high-flow pulse and overbank) defined by the Texas Instream Flow Program. Seasonal, annual and inter-annual flow component statistics were then coupled with biology, water quality and geomorphology overlays, where available, and with implementation rules applied to example large-scale water supply projects to support development of environmental flow standards for use in water rights permit conditions. The HEFR methodology and resulting flow recommendations are compared to two contemporary in-stream flow studies and adopted environmental flow standards. Subsistence flows were fairly similar. Baseflows were in a similar range, but fewer than three seasonal levels have sometimes been specified in in-stream flow studies. Episodic events are quite different in terms of magnitude, frequency, duration and applicable number. Editor D. Koutsoyiannis; Guest editor M. AcremanCitation Opdyke, D.R. Oborny, E.L. Vaugh, S.K. and Mayes, K.B. 2014. Texas environmental flow standards and the hydrology-based environmental flow regime methodology. Hydrological Sciences Journal, 59 (3-4), 820-830. © 2014 © 2014 IAHS Press. Source

Dong J.,Wilmar International | Yan W.,National Research Council Canada | Bock C.,National Research Council Canada | Nokhrina K.,National Research Council Canada | And 2 more authors.
BMC Plant Biology | Year: 2013

Background: myo-Inositol (Ins) metabolism during early stages of seed development plays an important role in determining the distributional relationships of some seed storage components such as the antinutritional factors, sucrose galactosides (also known as raffinose oligosaccharides) and phytic acid (PhA) (myo-inositol 1,2,3,4,5,6-hexakisphosphate). The former is a group of oligosaccharides, which plays a role in desiccation at seed maturation. They are not easily digested by monogastric animals, hence their flatulence-causing properties. Phytic acid is highly negatively charged, which chelates positive ions of essential minerals and decreases their bioavailability. It is also a major cause of phosphate-related water pollution. Our aim was to investigate the influence of competitive diversion of Ins as common substrate on the biosynthesis of phytate and sucrose galactosides. Results: We have studied the initial metabolic patterns of Ins in developing seeds of Brassica napus and determined that early stages of seed development are marked by rapid deployment of Ins into a variety of pathways, dominated by interconversion of polar (Ins phosphates) and non-polar (phospholipids) species. In a time course experiment at early stages of seed development, we show Ins to be a highly significant constituent of the endosperm and seed coat, but with no phytate biosynthesis occurring in either tissue. Phytate accumulation appears to be confined mainly within the embryo throughout seed development and maturation. In our approach, the gene for myo-inositol methyltransferase (IMT), isolated from Mesembryanthemum crystallinum (ice plant), was transferred to B. napus under the control of the seed-specific promoters, napin and phaseolin. Introduction of this new metabolic step during seed development prompted Ins conversion to the corresponding monomethyl ether, ononitol, and affected phytate accumulation. We were able to produce homozygous transgenic lines with 19% - 35% average phytate reduction. Additionally, changes in the raffinose content and related sugars occurred along with enhanced sucrose levels. Germination rates, viability and other seed parameters were unaffected by the IMT transgene over-expression. Conclusions: Competitive methylation of Ins during seed development reduces seed antinutritional components and enhances its nutritional characteristics while maintaining adequate phosphate reserves. Such approach should potentially raise the canola market value and likely, that of other crops. © 2013 Dong et al.; licensee BioMed Central Ltd. Source

Johnson M.S.,U.S. Fish and Wildlife Service | Johnson M.S.,Texas A&M University | Bolick A.,U.S. Fish and Wildlife Service | Alexander M.,U.S. Fish and Wildlife Service | And 5 more authors.
Journal of Parasitology | Year: 2012

Centrocestus formosanus (Trematoda: Heterophyidae) is an invasive fish parasite in the Comal River, Texas, and is considered a threat to the federally endangered fountain darter, Etheostoma fonticola. Monitoring densities of C. formosanus cercariae is crucial to determining levels of infection pressure. We sampled 3 sites in the Comal River during 2 sampling periods, the first during 2006-2007, and again during 2009-2010. Two of the sites were located in the upstream reach of Landa Lake, sites HS and LA, and the third site was located downstream of Landa Lake in the old channel of the river. Cercariae densities were highest at the downstream most site (EA), followed by sites LA and HS, during both sampling periods, but a significant decline in cercariae density was observed between the first and second sampling periods. Several abiotic factors were monitored, including total stream discharge, wading discharge, temperature, and dissolved oxygen, but no river-wide trends were observed. Therefore, we speculate that these factors do not adequately explain the observed long-term decline in cercariae density. We propose that the decline is simply a reflection of a typical pattern followed by most invasive species as they gradually become integrated into the local community following an initial explosive growth in population size. Although cercariae densities may be abating, fountain darters in the Comal River are still threatened by the parasite, and conservation efforts must focus on reducing levels of infection pressure from the parasite whenever possible. © American Society of Parasitologists 2012. Source

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