3,977 research outputs found

    The Influence of Geology and Season on Macroinvertebrates in Belizean Streams: Implications for Tropical Bioassessment

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    Considerable attention has been paid to the potentially confounding effects of geological and seasonal variation on outputs from bioassessments in temperate streams, but our understanding about these influences is limited for many tropical systems. We explored variation in macroinvertebrate assemblage composition and the environmental characteristics of 3rd- to 5th-order streams in a geologically heterogeneous tropical landscape in the wet and dry seasons. Study streams drained catchments with land cover ranging from predominantly forested to agricultural land, but data indicated that distinct water-chemistry and substratum conditions associated with predominantly calcareous and silicate geologies were key determinants of macroinvertebrate assemblage composition. Most notably, calcareous streams were characterized by a relatively abundant noninsect fauna, particularly a pachychilid gastropod snail. The association between geological variation and assemblage composition was apparent during both seasons, but significant temporal variation in compositional characteristics was detected only in calcareous streams, possibly because of limited statistical power to detect change at silicate sites, or the limited extent of our temporal data. We discuss the implications of our findings for tropical bioassessment programs. Our key findings suggest that geology can be an important determinant of macroinvertebrate assemblages in tropical streams and that geological heterogeneity may influence the scale of temporal response in characteristic macroinvertebrate assemblages

    Interview with Scott and Carrie Logan by Mike Hastings

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    Biographical NoteScott Logan was born on February 17, 1977, in Exeter, New Hampshire. His father, Terence Logan, held a Ph.D. from Harvard University and taught English at the University of New Hampshire. Scott’s mother was from rural southern Maryland, and they met at Newton College of the Sacred Heart, in Newton, Massachusetts, where Terence was a professor and Scott’s mother was a student. Scott grew up in Kennebunk, Maine, and was interested in collecting and selling antiques, and in local history. For this business, he received a scholarship from the National Association of the Self-Employed. He was also one of the first Mitchell Scholars, in 1995, attending Bowdoin College and graduating in 1999. He first met his future wife, Carrie, at Bowdoin through their mutual membership in Alpha Delta Phi fraternity. He worked at Christie’s Auction Company and then the auctioneering firm Skinner, Inc. He then attended law school at Boston College, and at the time of this interview, he was an attorney specializing in consumer bankruptcy. Carrie Logan was born on December 24, 1977, in Portland, Maine, to Donald McGilvery and Cheryl Poulin McGilvery. Her parents, both from Maine, met at Cony High School, and both were graduated from the University of Maine, Orono. Her father worked in architecture and construction management for the Maine State Housing Authority, and her mother worked in education and at the time of this interview was the secretary at William H. Rowe School in Yarmouth. Carrie grew up in Yarmouth, Maine, attended Yarmouth public schools, and was selected as a Mitchell Scholar. She attended Bowdoin College, where she met Scott, and was graduated with the class of 2000. Through the Teach For America program, she taught in Opelousas, Louisiana, for two years and then became an English-as-a-Second-Language teacher in Houston, Texas, before returning to Maine to study at the University of Maine School of Law. She took her law degree in 2007 and was practicing business and real estate law at Preti Flaherty in Portland, Maine, at the time of this interview. SummaryInterview includes discussion of: Scott’s family and educational background in Kennebunk; Scott’s antique bottle interest; Scott’s education; Carrie’s family and educational background in Yarmouth; the decision to go to Bowdoin College; paying for college; the Mitchell Institute and Mitchell Scholarship; life at Bowdoin and Alpha Delta Phi; Carrie’s work teaching in the South with Teach for America; coming back to Maine; Scott dealing antiques; and more recent involvement with the Mitchell Institute

    Osteopontin ablation ameliorates muscular dystrophy by shifting macrophages to a pro-regenerative phenotype.

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    In the degenerative disease Duchenne muscular dystrophy, inflammatory cells enter muscles in response to repetitive muscle damage. Immune factors are required for muscle regeneration, but chronic inflammation creates a profibrotic milieu that exacerbates disease progression. Osteopontin (OPN) is an immunomodulator highly expressed in dystrophic muscles. Ablation of OPN correlates with reduced fibrosis and improved muscle strength as well as reduced natural killer T (NKT) cell counts. Here, we demonstrate that the improved dystrophic phenotype observed with OPN ablation does not result from reductions in NKT cells. OPN ablation skews macrophage polarization toward a pro-regenerative phenotype by reducing M1 and M2a and increasing M2c subsets. These changes are associated with increased expression of pro-regenerative factors insulin-like growth factor 1, leukemia inhibitory factor, and urokinase-type plasminogen activator. Furthermore, altered macrophage polarization correlated with increases in muscle weight and muscle fiber diameter, resulting in long-term improvements in muscle strength and function in mdx mice. These findings suggest that OPN ablation promotes muscle repair via macrophage secretion of pro-myogenic growth factors
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