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Full-Text Articles in Physical Sciences and Mathematics

Mitochondrial Gene Rearrangements Confirm The Parallel Evolution Of The Crab-Like Form, C. L. Morrison, A. W. Harvey, S. Lavery, K. Tieu, Y. Huang, C. W. Cunningham Jul 2001

Mitochondrial Gene Rearrangements Confirm The Parallel Evolution Of The Crab-Like Form, C. L. Morrison, A. W. Harvey, S. Lavery, K. Tieu, Y. Huang, C. W. Cunningham

VIMS Articles

The repeated appearance of strikingly similar crab-like forms in independent decapod crustacean lineages represents a remarkable case of parallel evolution. Uncertainty surrounding the phylogenetic relationships among crab-like lineages has hampered evolutionary studies. As is often the case, aligned DNA sequences by themselves were unable to fully resolve these relationships. Four nested mitochondrial gene rearrangements—including one of the few reported movements of an arthropod protein-coding gene—are congruent with the DNA phylogeny and help to resolve a crucial node. A phylogenetic analysis of DNA sequences, and gene rearrangements, supported five independent origins of the crab-like form, and suggests that the evolution of …


Dynamic Bacterial And Viral Response To An Algal Bloom At Subzero Temperatures, Patricia L. Yager, Tara L. Connelly, Behzad Mortazavi, K. Eric Wommack, Nasreen Bano, James E. Bauer, Stephen Opsahl, James T. Hollibaugh Jun 2001

Dynamic Bacterial And Viral Response To An Algal Bloom At Subzero Temperatures, Patricia L. Yager, Tara L. Connelly, Behzad Mortazavi, K. Eric Wommack, Nasreen Bano, James E. Bauer, Stephen Opsahl, James T. Hollibaugh

VIMS Articles

New evidence suggests that cold‐loving (psychrophilic) bacteria may be a dynamic component of the episodic bloom events of high‐latitude ecosystems. Here we report the results of an unusually early springtime study of pelagic microbial activity in the coastal Alaskan Arctic. Heterotrophic bacterioplankton clearly responded to an algal bloom by doubling cell size, increasing the fraction of actively respiring cells (up to an unprecedented 84% metabolically active using redox dye CTC), shifting substrate‐uptake capabilities from kinetic parameters better adapted to lower substrate concentrations to those more suited for higher concentrations, and more than doubling cell abundance. Community composition (determined by polymerase …


The Paraguay-Paraná Hidrovía: Protecting The Pantanal With Lessons From The Past: Large-Scale Channelization Of The Northern Paraguay-Paraná Seems To Be On Hold, But An Ongoing Multitude Of Smaller-Scale Activities May Turn The Pantanal Into The Next Example Of The “Tyranny Of Small Decisions”, Johan F. Gottgens, James E. Perry, Et Al Apr 2001

The Paraguay-Paraná Hidrovía: Protecting The Pantanal With Lessons From The Past: Large-Scale Channelization Of The Northern Paraguay-Paraná Seems To Be On Hold, But An Ongoing Multitude Of Smaller-Scale Activities May Turn The Pantanal Into The Next Example Of The “Tyranny Of Small Decisions”, Johan F. Gottgens, James E. Perry, Et Al

VIMS Articles

Because it is one of the most inaccessible places on earth, this large, rich ecosystem has remained relatively untouched. There is, however, increasing evidence that this area is threatened by a number of activities, including mining, illegal hunting and fishing, indiscriminate use of fire, agricultural development, and deforestation. Careless use of mercury in gold mining, particularly in the northern Pantanal, may have resulted in acute and chronic ecosystem disruption (Hylander et al. 1994, Nogueira et al. 1997, Leady and Gottgens 2001). Wildlife poaching and live animal trade are widespread although hard to quantify. During six months in 1985, the skins …


Doc Cycling In A Temperate Estuary: A Mass Balance Approach Using Natural 14c And 13c Isotopes, Peter Raymond, James E. Bauer Jan 2001

Doc Cycling In A Temperate Estuary: A Mass Balance Approach Using Natural 14c And 13c Isotopes, Peter Raymond, James E. Bauer

VIMS Articles

We measured dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), and their corresponding D14C and d13C values in order to study the sources and fates of DOC in the York River Estuary (Virginia, U.S.A.). The D14C and d13C values of DOC and DIC at the freshwater end-member indicate that during periods of moderate to high flow, riverine DOC entering the York was composed of decadal-aged terrestrially organic matter. In nearly all cases, DOC concentrations exceeded conservative mixing lines and were therefore indicative of a net DOC input flux from within the estuary that averaged 1.2 mM L21 d21 . The …