Accumulation of heavy metals in food web components across a gradient of lakes

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109770/1/lno20004571525.pd

Intracapsular pressure and interleukin-1β cytokine in hips with acetabular dysplasia

Background and purpose Several studies have demonstrated an increased intracapsular pressure in several hip disorders such as septic arthritis, synovitis, and trauma. We therefore measured the intracapsular pressure in different positions in early dysplasic hips and its relation to the concentration of interleukin-1β (IL-1β), the volume of joint fluid, and the clinical and radiographic findings before a periacetabular osteotomy

Editing independent effects of ADARs on the miRNA/siRNA pathways

Adenosine deaminases acting on RNA (ADARs) are best known for altering the coding sequences of mRNA through RNA editing, as in the GluR-B Q/R site. ADARs have also been shown to affect RNA interference (RNAi) and microRNA processing by deamination of specific adenosines to inosine. Here, we show that ADAR proteins can affect RNA processing independently of their enzymatic activity. We show that ADAR2 can modulate the processing of mir-376a2 independently of catalytic RNA editing activity. In addition, in a Drosophila assay for RNAi deaminase-inactive ADAR1 inhibits RNAi through the siRNA pathway. These results imply that ADAR1 and ADAR2 have biological functions as RNA-binding proteins that extend beyond editing per se and that even genomically encoded ADARs that are catalytically inactive may have such functions

Algal blooms reduce the uptake of toxic methylmercury in freshwater food webs

Mercury accumulation in fish is a global public health concern, because fish are the primary source of toxic methylmercury to humans. Fish from all lakes do not pose the same level of risk to consumers. One of the most intriguing patterns is that potentially dangerous mercury concentrations can be found in fish from clear, oligotrophic lakes whereas fish from greener, eutrophic lakes often carry less mercury. In this study, we experimentally tested the hypothesis that increasing algal biomass reduces mercury accumulation at higher trophic levels through the dilution of mercury in consumed algal cells. Under bloom dilution, as algal biomass increases, the concentration of mercury per cell decreases, resulting in a lower dietary input to grazers and reduced bioaccumulation in algal-rich eutrophic systems. To test this hypothesis, we added enriched stable isotopes of Hg to experimental mesocosms and measured the uptake of toxic methylmercury (CH(3)(200)Hg(+)) and inorganic (201)Hg(2+) by biota at several algal concentrations. We reduced absolute spike detection limits by 50–100 times compared with previous techniques, which allowed us to conduct experiments at the extremely low aqueous Hg concentrations that are typical of natural systems. We found that increasing algae reduced CH(3)Hg(+) concentrations in zooplankton 2–3-fold. Bloom dilution may provide a mechanistic explanation for lower CH(3)Hg(+) accumulation by zooplankton and fish in algal-rich relative to algal-poor systems

Sorption of Mercuric Ion by Synthetic Nanocrystalline Mackinawite (FeS)

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155869/1/Jeong_et_al_2007_Sorption_of_Mercuric.pd

Impacts of zooplankton composition and algal enrichment on the accumulation of mercury in an experimental freshwater food web

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155858/1/Pickhardt_2005_Impacts_of_zooplankton.pd