Shifts in mid- to late-Holocene anion composition in Elk Lake (Grant County, Minnesota): Comparison of diatom and ostracode inferences

The fossil diatom record from Elk Lake (Grant County, Minnesota) was used to reconstruct salinity and brine type between 2640 and 4645 14C yr BP. This lake was selected for a brine-type reconstruction because a previous study using fossil-ostracode assemblages indicated a shift in anion composition during the mid-Holocene (Smith et al., 1997). Salinity was reconstructed using a transfer function developed for the Northern Great Plains (NGP) of North America; the reconstruction revealed that salinity was higher (1.5–6.2 g l−1) between ~4000 and 4645 14C yr BP and dropped to 0.35–1.2 g l−1 after 4000 14C yr BP. The anion composition of the system was investigated by passively plotting fossil diatom assemblages onto a canonical correspondence analysis (CCA) biplot of the NGP modern samples to determine where core assemblages fell with respect to brine type. The biplot suggests that Elk Lake was mainly a bicarbonate system, but temporarily shifted to sulfate domination at 4080 14C yr BP. Both the salinity and brine-type reconstructions essentially agree with results from Smith et al. (1997), but the diatom record provides less-definitive information on anion proportions as compared to anion concentrations. Because shifts in the relative abundances of anion-associated diatom taxa generally tracked the ostracode-inferred changes in brine type, we conclude that fossil diatom assemblages can reveal information on shifts in brine type over time and provide insight into brine evolution and groundwater behavior in a lake system

Book Reviews

Reviews of the following books: Maine: A Bicentennial History by Charles E. Clark; History, Records, Recollections of Gray, Maine by George T. Hill; History of the Town of Burlington, Penobscot County, Maine from Settlement to 1975 by Alan H. Hawkins; Charlie York: Maine Coast Fisherman by Harold B. Cliffor

Strategies for Clothing

This advanced unit of the ?4-H Clothing Project Series? expands further on the skills and knowledge learned in earlier programs, and prepares students for setting out on their own. Students will learn how to develop new ideas unique to their personalities. Creativity will be sparked, leadership skills will be honed, and volunteer opportunities will arise. Principles of design, fashion, clothes shopping, advanced fiber knowledge, tailoring, stain removal, care for accessories, skin care, hair coloring, posture, history, and interview preparation are covered along with many other topics. Upon completion of the curriculum, and sometimes much sooner, students will be able to develop their own unique ?Strategies for Clothing?, and apply their best thinking on many different levels as they enter adulthood

Strategies for Clothing

This advanced unit of the ?4-H Clothing Project Series? expands further on the skills and knowledge learned in earlier programs, and prepares students for setting out on their own. Students will learn how to develop new ideas unique to their personalities. Creativity will be sparked, leadership skills will be honed, and volunteer opportunities will arise. Principles of design, fashion, clothes shopping, advanced fiber knowledge, tailoring, stain removal, care for accessories, skin care, hair coloring, posture, history, and interview preparation are covered along with many other topics. Upon completion of the curriculum, and sometimes much sooner, students will be able to develop their own unique ?Strategies for Clothing?, and apply their best thinking on many different levels as they enter adulthood

Local Role for Tumor Necrosis Factor Alpha in the Pulmonary Inflammatory Response to Mycobacterium tuberculosis Infection

The local intrapulmonary role of tumor necrosis factor alpha (TNF-α) in a protective host response during acute and chronic infection with Mycobacterium tuberculosis is incompletely understood. To directly assess its role in the intrapulmonary immune response, we compared the responses of transgenic mice with a local pulmonary blockade of TNF-α (SPCTNFRIIFc mice) to mice with globally inhibited TNF-α (TNFRKO mice) and mice with normal immune systems (control mice). Consistent with previous reports, 100% of TNFRKO mice died by 28 days after aerosol infection, and these mice had markedly increased numbers of bacteria and widespread tissue necrosis in their lungs compared to controls. The median survival time of the SPCTNFRIIFc mice was 142 days, and 75% died by 180 days. Even though the numbers of bacteria in the lungs of the SPCTNFRIIFc mice were marginally increased compared to controls, these mice had a persistent neutrophilic inflammatory response and increased expression of proinflammatory cytokines (interleukin-1α/β [IL-1α/β], IL-18, gamma interferon, IL-6, and macrophage migration inhibitory factor) and chemokines (eotaxin, macrophage inflammatory protein 1α/β, gamma interferon-inducible protein 10, macrophage chemotaxic protein 1, and TCA-3) in their lungs. These studies with the SPCTNFRIIFc mice provide direct evidence for the local importance of TNF-α in the proper regulation of host defense to M. tuberculosis. The studies also suggest that when the local actions of TNF-α are selectively impaired in the lungs, tissue destruction and death ensue, at least in part, due to persistent expression of proinflammatory mediators that would normally be downregulated