The Experts below are selected from a list of 75 Experts worldwide ranked by ideXlab platform
Adam C. Rich - One of the best experts on this subject based on the ideXlab platform.
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Habitat relationships of great gray owl prey in meadows of the Sierra Nevada Mountains
Wildlife Society Bulletin, 2014Co-Authors: Ryan S. Kalinowski, Matthew D. Johnson, Adam C. RichAbstract:Annual productivity of great gray owls (Strix nebulosa) in California, USA, is thought to be largely dependent on vole (Microtus spp.) and pocket gopher (Thomomys spp.; hereafter, gopher) abundance, yet factors influencing these prey populations have not been thoroughly investigated. The abundance of voles and gophers has been influenced by vegetation and cattle grazing in other regions; and many meadows are grazed within the breeding range of great gray owls in the Sierra Nevada Mountains of California. We evaluated the influence of vegetation and cattle grazing on great gray owl foraging habitat by quantifying vole abundance, gopher abundance, and vegetation features in grazed and ungrazed meadows in 2010 and 2011. We found that vole presence was positively associated with sward height and Corn Lily (Veratrum californicum) dominance; vole abundance was weakly negatively associated with cattle grazing. Gopher abundance was negatively associated with site wetness, and weakly positively associated with stem density, the frequency of forb presence, cattle grazing, and the dominance of Corn Lily. To efficiently manage vegetation and cattle grazing to benefit great gray owl prey, we suggest prioritizing habitat for voles in wet meadows because gophers were not likely to be abundant in wet sites. Particularly in areas with moist soils, we recommend maintaining sward height commensurate with the habitat relationships of voles found in this study; >290 mm where Corn Lily is not dominant and 125 mm where it is. Sustaining sward height for voles should benefit great gray owls and other meadow or forest edge carnivores. © 2014 The Wildlife Society.
Heidi Hahn - One of the best experts on this subject based on the ideXlab platform.
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Cyclopamine treatment of full-blown Hh/Ptch-associated RMS partially inhibits Hh/Ptch signaling, but not tumor growth.
Molecular carcinogenesis, 2008Co-Authors: Ines Ecke, Albert Rosenberger, Silvia Obenauer, Christian Dullin, Fritz Aberger, Sarah Kimmina, Stefan Schweyer, Heidi HahnAbstract:Mutations in the Hedgehog (Hh) receptor Patched (Ptch) are responsible for a variety of tumors, which show ligand-independent stimulation of the Hh/Ptch signaling cascade. Cyclopamine is an alkaloid of the Corn Lily Veratrum californicum, which blocks activity of the pathway by inhibition of Smoothened (Smo), the signal transduction partner of Ptch. This results in growth inhibition of Hh/Ptch-dependent tumor cells in vitro, of subcutaneous xenografts as well as of precancerous lesions in Ptch+/− mice. However, the evidence that treatment with cyclopamine is an effective anti-cancer therapy against full-blown tumors is sparse. Here, we have investigated the responsiveness of full-blown Hh/Ptch-associated rhabdomyosarcoma (RMS) to this drug. Hh pathway activity and proliferation of cultured primary RMS cells was inhibited by cyclopamine. Hh signaling was also partially suppressed by the drug in RMS in vivo, but cyclopamine treatment did not result in stable disease or tumor regression. It also did not affect proliferation, apoptosis or the differentiation status of RMS. This was in contrast to anti-proliferative effects on tumor growth caused by doxorubicin, an anthracycline routinely used in therapy of human RMS. In summary, our data indicate that there must be additional factors that render full-blown Hh/Ptch-associated RMS insensitive against anti-proliferative effects of cyclopamine in vivo. © 2007 Wiley-Liss, Inc.
Ryan S. Kalinowski - One of the best experts on this subject based on the ideXlab platform.
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Habitat relationships of great gray owl prey in meadows of the Sierra Nevada Mountains
Wildlife Society Bulletin, 2014Co-Authors: Ryan S. Kalinowski, Matthew D. Johnson, Adam C. RichAbstract:Annual productivity of great gray owls (Strix nebulosa) in California, USA, is thought to be largely dependent on vole (Microtus spp.) and pocket gopher (Thomomys spp.; hereafter, gopher) abundance, yet factors influencing these prey populations have not been thoroughly investigated. The abundance of voles and gophers has been influenced by vegetation and cattle grazing in other regions; and many meadows are grazed within the breeding range of great gray owls in the Sierra Nevada Mountains of California. We evaluated the influence of vegetation and cattle grazing on great gray owl foraging habitat by quantifying vole abundance, gopher abundance, and vegetation features in grazed and ungrazed meadows in 2010 and 2011. We found that vole presence was positively associated with sward height and Corn Lily (Veratrum californicum) dominance; vole abundance was weakly negatively associated with cattle grazing. Gopher abundance was negatively associated with site wetness, and weakly positively associated with stem density, the frequency of forb presence, cattle grazing, and the dominance of Corn Lily. To efficiently manage vegetation and cattle grazing to benefit great gray owl prey, we suggest prioritizing habitat for voles in wet meadows because gophers were not likely to be abundant in wet sites. Particularly in areas with moist soils, we recommend maintaining sward height commensurate with the habitat relationships of voles found in this study; >290 mm where Corn Lily is not dominant and 125 mm where it is. Sustaining sward height for voles should benefit great gray owls and other meadow or forest edge carnivores. © 2014 The Wildlife Society.
Ines Ecke - One of the best experts on this subject based on the ideXlab platform.
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Cyclopamine treatment of full-blown Hh/Ptch-associated RMS partially inhibits Hh/Ptch signaling, but not tumor growth.
Molecular carcinogenesis, 2008Co-Authors: Ines Ecke, Albert Rosenberger, Silvia Obenauer, Christian Dullin, Fritz Aberger, Sarah Kimmina, Stefan Schweyer, Heidi HahnAbstract:Mutations in the Hedgehog (Hh) receptor Patched (Ptch) are responsible for a variety of tumors, which show ligand-independent stimulation of the Hh/Ptch signaling cascade. Cyclopamine is an alkaloid of the Corn Lily Veratrum californicum, which blocks activity of the pathway by inhibition of Smoothened (Smo), the signal transduction partner of Ptch. This results in growth inhibition of Hh/Ptch-dependent tumor cells in vitro, of subcutaneous xenografts as well as of precancerous lesions in Ptch+/− mice. However, the evidence that treatment with cyclopamine is an effective anti-cancer therapy against full-blown tumors is sparse. Here, we have investigated the responsiveness of full-blown Hh/Ptch-associated rhabdomyosarcoma (RMS) to this drug. Hh pathway activity and proliferation of cultured primary RMS cells was inhibited by cyclopamine. Hh signaling was also partially suppressed by the drug in RMS in vivo, but cyclopamine treatment did not result in stable disease or tumor regression. It also did not affect proliferation, apoptosis or the differentiation status of RMS. This was in contrast to anti-proliferative effects on tumor growth caused by doxorubicin, an anthracycline routinely used in therapy of human RMS. In summary, our data indicate that there must be additional factors that render full-blown Hh/Ptch-associated RMS insensitive against anti-proliferative effects of cyclopamine in vivo. © 2007 Wiley-Liss, Inc.
Matthew D. Johnson - One of the best experts on this subject based on the ideXlab platform.
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Habitat relationships of great gray owl prey in meadows of the Sierra Nevada Mountains
Wildlife Society Bulletin, 2014Co-Authors: Ryan S. Kalinowski, Matthew D. Johnson, Adam C. RichAbstract:Annual productivity of great gray owls (Strix nebulosa) in California, USA, is thought to be largely dependent on vole (Microtus spp.) and pocket gopher (Thomomys spp.; hereafter, gopher) abundance, yet factors influencing these prey populations have not been thoroughly investigated. The abundance of voles and gophers has been influenced by vegetation and cattle grazing in other regions; and many meadows are grazed within the breeding range of great gray owls in the Sierra Nevada Mountains of California. We evaluated the influence of vegetation and cattle grazing on great gray owl foraging habitat by quantifying vole abundance, gopher abundance, and vegetation features in grazed and ungrazed meadows in 2010 and 2011. We found that vole presence was positively associated with sward height and Corn Lily (Veratrum californicum) dominance; vole abundance was weakly negatively associated with cattle grazing. Gopher abundance was negatively associated with site wetness, and weakly positively associated with stem density, the frequency of forb presence, cattle grazing, and the dominance of Corn Lily. To efficiently manage vegetation and cattle grazing to benefit great gray owl prey, we suggest prioritizing habitat for voles in wet meadows because gophers were not likely to be abundant in wet sites. Particularly in areas with moist soils, we recommend maintaining sward height commensurate with the habitat relationships of voles found in this study; >290 mm where Corn Lily is not dominant and 125 mm where it is. Sustaining sward height for voles should benefit great gray owls and other meadow or forest edge carnivores. © 2014 The Wildlife Society.