Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 7 of 7
Full-Text Articles in Biology
Telomere Structure And Shortening In Telomerase-Deficient Trypanosoma Brucei, Oliver Dreesen, Bibo Li, George A.M. Cross
Telomere Structure And Shortening In Telomerase-Deficient Trypanosoma Brucei, Oliver Dreesen, Bibo Li, George A.M. Cross
Biological, Geological, and Environmental Faculty Publications
Telomerase consists of a reverse transcriptase (TERT) and an RNA that contains a template for telomere-repeat extension. Telomerase is required to prevent telomere erosion and its activity or lack thereof is important for tumorigenesis and ageing. Telomerase has been identified in numerous organisms but it has not been studied in kinetoplastid protozoa. Trypanosoma brucei, the causative agent of African sleeping sickness, evades the host immune response by frequently changing its variant surface glycoprotein (VSG). The single expressed VSG is transcribed from one of ∼20 subtelomeric 'Expression Sites', but the role telomeres might play in regulating VSG transcription and switching is …
Dominant Processes Controlling Water Chemistry Of The Pecos River In American Southwest, Fasong Yuan, Seiichi Miyamoto
Dominant Processes Controlling Water Chemistry Of The Pecos River In American Southwest, Fasong Yuan, Seiichi Miyamoto
Biological, Geological, and Environmental Faculty Publications
Here we show an analysis of river flow and water chemistry data from eleven gauging stations along the Pecos River in eastern New Mexico and western Texas, with time spanning 1959–2002. Analysis of spatial relationship between the long-term average flow and total dissolved solids (TDS) concentration allows us to illuminate four major processes controlling river chemistry, namely saline water addition, evaporative concentration with salt gain or loss, dilution with salt gain or loss, and salt storage. Of the 10 river reaches studied, six reaches exhibit the process dominated by evaporative concentration or freshwater dilution with little change in salt load. …
Geographical Distributions, Relative Abundance And Coexistence Of Drosophila Aldrichi And Drosophila Buzzatii In Australia, J. S.F. Barker, Robert A. Krebs, H. I. Davies
Geographical Distributions, Relative Abundance And Coexistence Of Drosophila Aldrichi And Drosophila Buzzatii In Australia, J. S.F. Barker, Robert A. Krebs, H. I. Davies
Biological, Geological, and Environmental Faculty Publications
Climatic data and collection records for the cactophilic Drosophila aldrichi and Drosophila buzzatii for 97 localities were used to examine the effects of geographical location, season, host plant species and climatic factors on their range and relative abundance. Temporal variation in relative abundance was assessed from monthly collections over 4 years at one locality. Effects of weather variables over the 28 days before each collection were examined. A generalized linear model of the spatial data showed significant geographical variation in relative abundance, and significant climatic effects, with the proportion of D. aldrichi higher in the warm season, and increasing as …
The Unionid Mussel Fauna Of Northeastern Ohio’S Grand River, Martin K. Huehner, Robert A. Krebs, Gregory Zimmerman, Melissa Mejia
The Unionid Mussel Fauna Of Northeastern Ohio’S Grand River, Martin K. Huehner, Robert A. Krebs, Gregory Zimmerman, Melissa Mejia
Biological, Geological, and Environmental Faculty Publications
Unionid mussel distribution, numbers, and species were examined in the Grand River to provide a recent and comprehensive study of mussels from northeast Ohio’s longest river. The entire length of the Grand was canoed and examined for unionid mussel beds, with the exception of upstream areas where the river was small; SCUBA was used to survey just upstream of Fairport Harbor. The lower river, designated Grand River’s Wild and Scenic section, was studied in 1995, the middle reaches, called the Scenic section, were surveyed in 1996, and completion of the headwater region followed in 1998. Finally, a survey near the …
A Genetic Analysis Of Variation For The Ability To Fly After Exposure Tothermal Stress In Drosophila Mojavensis, Robert A. Krebs, Kimberly A. Thompson
A Genetic Analysis Of Variation For The Ability To Fly After Exposure Tothermal Stress In Drosophila Mojavensis, Robert A. Krebs, Kimberly A. Thompson
Biological, Geological, and Environmental Faculty Publications
To help us understand how adaptive tolerance to heat stress has evolved, we made F1 hybrid crosses and backcrosses amongst populations of Drosophila mojavensis, and tested their ability to fly after exposure to a debilitating, but non-lethal, heat stress. Previous work identified that these populations vary in thermotolerance as measured for a variety of traits. Hybrid superiority was observed when crossing all four pairs of strains. Patterns of inheritance in flight ability after stress varied depending on which strains were used to set up complete reciprocal backcrosses, and, for both population pairs, results supported a multigenic model. This …
Diversity Of The Unionidae In The Rocky River, Ohio, Robert A. Krebs, Louie J. Rundo
Diversity Of The Unionidae In The Rocky River, Ohio, Robert A. Krebs, Louie J. Rundo
Biological, Geological, and Environmental Faculty Publications
We surveyed the freshwater mussels (Mollusca: Bivalvia: Unionidae) of the Rocky River, Ohio, USA, a river surrounded by suburban development. The survey produced 253 live unionid specimens and 572 empty shells. Most occurred in the west branch. Species living in the West Branch Rocky River included Anodontoides ferussacianus, Elliptio dilatata, Lampsilis cardium, Lampsilis radiata luteola, Lasmigona compressa, Lasmigona costata, Pyganodon grandis grandis, Strophitus undulatus undulatus, and Toxolasma parvus. Two additional species (Utterbackia imbecillis and Villosa iris iris) were represented as dead shells. Three species (Potamilis alatus, Quadrula quadrula and Leptodea fragilis) were found only near the …
Analytical Solutions For Vertical Flow In Unsaturated, Rooted Soils With Variable Surface Fluxes, Fasong Yuan, Zhiming Lu
Analytical Solutions For Vertical Flow In Unsaturated, Rooted Soils With Variable Surface Fluxes, Fasong Yuan, Zhiming Lu
Biological, Geological, and Environmental Faculty Publications
Analytical solutions to Richards' equation have been derived to describe the distribution of pressure head, water content, and fluid flow for rooted, homogeneous soils with varying surface fluxes. The solutions assume that (i) the constitutive relations for the hydraulic conductivity and water content as function of the pressure head are exponential, (ii) the initial water content distribution is a steady-state distribution, and (iii) the root water uptake is a function of depth. Three simple forms of root water uptake are considered, that is, uniform, stepwise, and exponential functional forms. The lower boundary of the rooted soil profile studied is a …