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Full-Text Articles in Life Sciences

Urban Stream Burial Increases Watershed-Scale Nitrate Export, Jake J. Beaulieu, Heather E. Golden, Christopher D. Knightes, Paul M. Mayer, Sujay S. Kaushal, Michael J. Pennino, Clay P. Arango, David A. Balz, Colleen M. Elonen, Ken M. Fritz, Brian H. Hill Jul 2015

Urban Stream Burial Increases Watershed-Scale Nitrate Export, Jake J. Beaulieu, Heather E. Golden, Christopher D. Knightes, Paul M. Mayer, Sujay S. Kaushal, Michael J. Pennino, Clay P. Arango, David A. Balz, Colleen M. Elonen, Ken M. Fritz, Brian H. Hill

All Faculty Scholarship for the College of the Sciences

Nitrogen (N) uptake in streams is an important ecosystem service that reduces nutrient loading to downstream ecosystems. Here we synthesize studies that investigated the effects of urban stream burial on N-uptake in two metropolitan areas and use simulation modeling to scale our measurements to the broader watershed scale. We report that nitrate travels on average 18 times farther downstream in buried than in open streams before being removed from the water column, indicating that burial substantially reduces N uptake in streams. Simulation modeling suggests that as burial expands throughout a river network, N uptake rates increase in the remaining open …


Osteological Variation Among Extreme Morphological Forms In The Mexican Salamander Genus Chiropterotriton (Amphibia: Plethodontidae): Morphological Evolution And Homoplasy, David M. Darda, David B. Wake Jun 2015

Osteological Variation Among Extreme Morphological Forms In The Mexican Salamander Genus Chiropterotriton (Amphibia: Plethodontidae): Morphological Evolution And Homoplasy, David M. Darda, David B. Wake

All Faculty Scholarship for the College of the Sciences

Osteological variation is recorded among and within four of the most distinctive species of the Mexican salamander genus Chiropterotriton. Analysis of the data is consistent with the monophyletic status of the genus and documents previously unrecorded intraspecific and interspecific variation. Most of the recorded variation involves qualitative and quantitative proportional differences, but four fixed differences constitute autapomorphic states that affirm and diagnose some species (C. dimidiatus, C. magnipes). Osteological variation in 15 characters is analyzed with respect to predictions generated from four hypotheses: 1) phylogeny, 2) adaptation to specific habitats (the four species include …


Collective Movement In The Tibetan Macaques (Macaca Thibetana): Early Joiners Write The Rule Of The Game, Xi Wang, Lixing Sun, Jinhua Li, Dongpo Xia, Binghua Sun, Dao Zhang May 2015

Collective Movement In The Tibetan Macaques (Macaca Thibetana): Early Joiners Write The Rule Of The Game, Xi Wang, Lixing Sun, Jinhua Li, Dongpo Xia, Binghua Sun, Dao Zhang

All Faculty Scholarship for the College of the Sciences

Collective behavior has recently attracted a great deal of interest in both natural and social sciences. While the role of leadership has been closely scrutinized, the rules used by joiners in collective decision making have received far less attention. Two main hypotheses have been proposed concerning these rules: mimetism and quorum. Mimetism predicts that individuals are increasingly likely to join collective behavior as the number of participants increases. It can be further divided into selective mimetism, where relationships among the participants affect the process, and anonymous mimetism, where no such effect exists. Quorum predicts that a collective behavior occurs when …


Saffron Cod (Eleginus Gracilis) In North Pacific Archaeology, Megan A. Partlow, Eric Munk Jan 2015

Saffron Cod (Eleginus Gracilis) In North Pacific Archaeology, Megan A. Partlow, Eric Munk

All Faculty Scholarship for the College of the Sciences

Saffron cod (Eleginus gracilis) is a marine species often found in shallow, brackish water in the Bering Sea, although it can occur as far southeast as Sitka, Alaska. Recently, we identified saffron cod remains in two ca. 500-year-old Afognak Island midden assemblages from the Kodiak Archipelago. We developed regression formulae to relate bone measurements to total length using thirty-five modern saffron cod specimens. The archaeological saffron cod remains appear to be from mature adults, measuring 22–45 cm in total length, and likely caught from shore during spawning. Saffron cod may have been an important winter resource for Alutiiq people living …


Effect Of High Light Intensity On Photoinhibition, Oxyradicals And Artemisinin Content In Artemisia Annua L., Mary E. Poulson, T. Thai Jan 2015

Effect Of High Light Intensity On Photoinhibition, Oxyradicals And Artemisinin Content In Artemisia Annua L., Mary E. Poulson, T. Thai

Biology Faculty Scholarship

Artemisia annua L. produces a compound called artemisinin that is a potent anti-malarial compound. However concentration of artemisinin within the plant is typically low (less than 0.8% of dry mass) and currently supply of the drug by the plant does not meet world demand. This investigation was carried out to determine whether high intensity light treatment would increase production of artemisinin in leaves of A. annua. Photoinhibition (14%) was induced in leaves of A. annua when they were subjected to 6 h of high-intensity light [2,000 μmol (photon) m–2 s–1]. Maximum photochemical efficiency of PSII showed …