52 research outputs found
Phylogenetic revision of Rhineuridae (Reptilia: Squamata: Amphisbaenia) from the Eocene to Miocene of North America
20 p., 6 fig., 1 tablehttp://paleo.ku.edu/contributions.htm
Neoichnological evidence of predatory behavior in soil arthropods and its application to continental trace fossils
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Precision overhead irrigation is suitable for several Central Valley crops
Overhead systems are the dominant irrigation technology in many parts of the world, but they are not widely used in California even though they have higher water application efficiency than furrow irrigation systems and lower labor requirements than drip systems. With water and labor perennial concerns in California, the suitability of overhead systems merits consideration. From 2008 through 2013, in studies near Five Points, California, we evaluated overhead irrigation for wheat, corn, cotton, tomato, onion and broccoli as an alternative to furrow and drip irrigation. With the exception of tomato, equal or increased yields were achieved with overhead irrigation. Many variables are involved in the choice of an irrigation system, but our results suggest that, with more research to support best management practices, overhead irrigation may be useful to a wider set of California farmers than currently use it
Differential colonization with segmented filamentous bacteria and Lactobacillus murinus do not drive divergent development of diet-induced obesity in C57BL/6 mice
Alterations in the gut microbiota have been proposed to modify the development and maintenance of obesity and its sequelae. Definition of underlying mechanisms has lagged, although the ability of commensal gut microbes to drive pathways involved in inflammation and metabolism has generated compelling, testable hypotheses. We studied C57BL/6 mice from two vendors that differ in their obesogenic response and in their colonization by specific members of the gut microbiota having well-described roles in regulating gut immune responses. We confirmed the presence of robust differences in weight gain in mice from these different vendors during high fat diet stress. However, neither specific, highly divergent members of the gut microbiota (Lactobacillus murinus, segmented filamentous bacteria) nor the horizontally transmissible gut microbiota were found to be responsible. Constitutive differences in locomotor activity were observed, however. These data underscore the importance of selecting appropriate controls in this widely used model of human obesity
Evaluating the Role of Hormone Therapy in Postmenopausal Women with Alzheimer’s Disease
Examining Local Climate Variability in the Late Pennsylvanian Through Paleosols: An Example from the Lower Conemaugh Group of Southeastern Ohio, USA
Three temporally close stratigraphic sections were excavated in Glenshaw Formation of Athens County, Ohio. The described units are Upper Pennsylvanian (Gzhelian, 305–302 Ma) and located in the distal portion of the Appalachian foreland basin. Mudstone units interpreted as paleosols were identified across all three sections. Detailed field and micromorphological studies lead to the recognition of two separate paleosols within the profile. The profile consists of a composite paleosol composed of two cumulative paleosols. The lower paleosol is interpreted as a calcic Vertisol which formed in a seasonally dry environment whereas the upper paleosol is interpreted as a gleyed Inceptisol which formed in a seasonally wet environment. The change in paleosol types is the result of increased precipitation which led to saturation of the soil and surface ponding. Pedogenic carbonate nodules are a common feature throughout the entire profile as are stress cutans. A coalesced carbonate horizon (Bk) was observed approximate 120 cm from the top of the profile in all three sections. This carbonate horizon formed in the Vertisol and later served as a barrier which limited the downward movement of surface water. This limited the gleization of the bottom portion of the overprinted Vertisol resulting in a diffuse boundary with the overlying Inceptisol and producing a composite paleosol
Recognizing Vertical and Lateral Variability in Terrestrial Landscapes: A Case Study from the Paleosols of the Late Pennsylvanian Casselman Formation (Conemaugh Group) Southeast Ohio, USA
The Upper Pennsylvanian Casselman Formation of southeastern Ohio contains four distinct paleosol types that formed in alluvial systems within the distal Appalachian foreland basin. The properties of these paleosols as well as their small-scale lateral and vertical variations were studied to interpret the paleoenvironmental and paleoecological conditions within the alluvial settings in which they formed. The ichnofossils and pedogenic features preserved within the paleosols of the Casselman Formation record the local climactic, hydrologic, biotic, and topographic changes that occurred in the region during the Late Pennsylvanian. The four paleosols types of the Casselman Formation are interpreted as Alfisols (Type A, Type D), Vertisols (Type B), and Inceptisols (Type D). The four paleosol types indicate different degrees of changes in local moisture regimes including water table fluctuations due to seasonal precipitation and flooding events. The assemblages of ichnofossils within the paleosol types were produced by both soil arthropods and a diverse array of plants that formed part of the different soil ecosystems present within the alluvial environment. Although regional-scale studies are important for understanding the Late Pennsylvanian world, small-scale studies are also necessary to fully understand the local pedogenic, paleoenvironmental, and paleoecologic consequences of global scale changes in paleoclimate and paleogeography
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