Daily Archives: August 16, 2011

Hydrochaerus hydrochaeris at Paso Robles, CA

Only in California: The world’s largest rodent, the Capybaras, now inhabits the wastewater plant at Paso Robles, California…..click here for news article.

Click for more about the Capybaras.

Wind Turbines = Bird Choppers

The fact that birds are killed by wind turbines has been known for many years. Perhaps it is now finally being recognized…..and what if one of those birds is an endangered species?

California has about 2,500 golden eagles. The state’s largest wind farms kills an average of at least 80 eagles per year. If the wind turbine capacity is tripled, how long will it take to eliminate all of the remaining golden eagles?

Click here for more.


Water Projects in Tibet

China to spend $1.8 billion USD on water projects in Tibet.  Click here.

LaBreche et al 2011: Peripheral Blood Signatures of Lead Exposure

An interesting study examining blood changes as a result of lead in blood. A low-level signature was identified at an estimated blood lead level of 3.3 ug/dL. This is below the 10 ug/dL level for children set by the Centers for Disease Control. However, the signatures were not indicators of past exposure. Gene expression data generated by such studies provide molecular information useful in understanding the biological processes, but many gaps remain in our understanding of the effects of Pb.

 LaBreche H.G., S.K. Meadows, J.R. Nevins, and J.P. Chute 2011. Peripheral Blood Signatures of Lead Exposure. PLoS ONE 6(8): e23043. doi:10.1371/journal.pone.0023043

Click here for the abstract (also below) and the full paper (open source).

Background:  Current evidence indicates that even low-level lead (Pb) exposure can have detrimental effects, especially in children. We tested the hypothesis that Pb exposure alters gene expression patterns in peripheral blood cells and that these changes reflect dose-specific alterations in the activity of particular pathways.

Methodology/Principal Finding: Using Affymetrix Mouse Genome 430 2.0 arrays, we examined gene expression changes in the peripheral blood of female Balb/c mice following exposure to per os lead acetate trihydrate or plain drinking water for two weeks and after a two-week recovery period. Data sets were RMA-normalized and dose-specific signatures were generated using established methods of supervised classification and binary regression. Pathway activity was analyzed using the ScoreSignatures module from GenePattern.

Conclusions/Significance: The low-level Pb signature was 93% sensitive and 100% specific in classifying samples a leave-one-out crossvalidation. The high-level Pb signature demonstrated 100% sensitivity and specificity in the leave-one-out crossvalidation. These two signatures exhibited dose-specificity in their ability to predict Pb exposure and had little overlap in terms of constituent genes. The signatures also seemed to reflect current levels of Pb exposure rather than past exposure. Finally, the two doses showed differential activation of cellular pathways. Low-level Pb exposure increased activity of the interferon-gamma pathway, whereas high-level Pb exposure increased activity of the E2F1 pathway.