49 research outputs found
Use of areal snow cover measurements from ERTS-1 imagery in snowmelt-runoff relationships in Arizona
Methods of interpreting ERTS-1 imagery to measure areal snow cover were analyzed. Relationship of areal snow cover and runoff were among the objectives in this study of ERTS-1 imagery use for forecasting snowmelt-runoff relationships
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Sensitivity of Lipid Metabolism and Insulin Signaling to Genetic Alterations in Hepatic Peroxisome Proliferator–Activated Receptor- Coactivator-1 Expression
Objective: The peroxisome proliferator–activated receptor- coactivator (PGC)-1 family of transcriptional coactivators controls hepatic function by modulating the expression of key metabolic enzymes. Hepatic gain of function and complete genetic ablation of PGC-1 show that this coactivator is important for activating the programs of gluconeogenesis, fatty acid oxidation, oxidative phosphorylation, and lipid secretion during times of nutrient deprivation. However, how moderate changes in PGC-1 activity affect metabolism and energy homeostasis has yet to be determined. Research Design and Methods: To identify key metabolic pathways that may be physiologically relevant in the context of reduced hepatic PGC-1 levels, we used the Cre/Lox system to create mice heterozygous for PGC-1 specifically within the liver (LH mice). Results: These mice showed fasting hepatic steatosis and diminished ketogenesis associated with decreased expression of genes involved in mitochondrial -oxidation. LH mice also exhibited high circulating levels of triglyceride that correlated with increased expression of genes involved in triglyceride-rich lipoprotein assembly. Concomitant with defects in lipid metabolism, hepatic insulin resistance was observed both in LH mice fed a high-fat diet as well as in primary hepatocytes. Results: These data highlight both the dose-dependent and long-term effects of reducing hepatic PGC-1 levels, underlining the importance of tightly regulated PGC-1 expression in the maintenance of lipid homeostasis and glucose metabolism
Forest thinning impacts on the water balance of Sierra Nevada mixed-conifer headwater basins
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ARIZONA WATERSHED SYMPOSIA: A FORUM FOR REPORTING EARLY WATERSHED MANAGEMENT ACTIVITIES
The role of the Arizona Water Resources Committee and the goal of the Arizona Watershed Program in the early watershed management activities of the state are presented in the introduction of this paper to place its contents in perspective. The Arizona Watershed Resources Committee was a “citizen's advisory committee” that was formed in 1956 to assist in implementing the recommendations made in historic Barr Report to increase water yields and enhance the other natural resources found on the watersheds in the Salt and Verde River Basins of north-central Arizona (Fox et al. 2000). The Barr Report had been released to the public in the form of a short summary publication (Part I) and a more detailed and comprehensive document (Part II), both with the intriguing title of “Recovering Rainfall - More Water for Irrigation,” in the fall of 1956 (Barr 1956a, 1956b, respectively). Contents of the report supported the belief of members of the Arizona Water Resources Committee and many other people that the state's watersheds were in “bad shape” while providing what was called a “scientific basis” for improving these conditions by more intensive watershed management to primarily increase streamflow volumes.
The Arizona Watershed Program was a collaborative initiative of the Arizona Water Resources Committee, the Watershed Management Division of the Arizona State Land Department, and the U.S. Forest Service and their cooperators to investigate the effects of vegetative management practices on the hydrologic processes affecting water yields and incorporate the findings obtained into watershed management practices (Fox et al. 2000). It was planned that this general goal would be met by three “highly integrated” programs – a research program, an action program, and a public relations program. Findings of the research and action programs have been reported by Ffolliott and Thorud (1974, 1975), Hibbert (1979), Baker and Ffolliott (1998), Baker (1999), Neary et al. (2002, 2008), DeBano et al. (2004), Solomon and Schmidt (1981), and others. A main component of the public relations program – the Arizona Watershed Symposia – is the focus of this paper.This article is part of the Hydrology and Water Resources in Arizona and the Southwest collections. Digital access to this material is made possible by the Arizona-Nevada Academy of Science and the University of Arizona Libraries. For more information about items in this collection, contact [email protected]
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Solar Radiation as Indexed by Clouds for Snowmelt Modeling
From the Proceedings of the 1978 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 14-15, 1978, Flagstaff, ArizonaIn an effort to improve the methods of forecasting the amount and timing of snowmelt, a primary source of water in Arizona, significant regression equations are developed over a selected measurement period to relate global, direct, and diffuse solar radiation to: (1) the cloud-cover of specific cloud genera, (2) the hour before or after solar noon, and (3) the potential solar radiation. Three regression equations are derived from cloud-cover imagery and solar radiation data collected from two sites in Arizona 's Ponderosa pine forests, Schnebly Hill, and Alpine, in the hope that regression models will be useful in the simulation of snowpack dynamics.This article is part of the Hydrology and Water Resources in Arizona and the Southwest collections. Digital access to this material is made possible by the Arizona-Nevada Academy of Science and the University of Arizona Libraries. For more information about items in this collection, contact [email protected]
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Predicting Solar Radiation from Cloud Cover for Snowmelt Modeling
From the Proceedings of the 1987 Meetings of the Arizona Section - American Water Resources Association, Hydrology Section - Arizona-Nevada Academy of Science and the Arizona Hydrological Society - April 18, 1987, Northern Arizona University, Flagstaff, ArizonaThis article is part of the Hydrology and Water Resources in Arizona and the Southwest collections. Digital access to this material is made possible by the Arizona-Nevada Academy of Science and the University of Arizona Libraries. For more information about items in this collection, contact [email protected]
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A Selected and Annotated Bibliography of Understory-Overstory Vegetation Relationships
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Predicting Herbage Production from Forest Growth in Arizona Ponderosa Pine
This item is part of the Arizona Land and People (formerly Progressive Agriculture in Arizona) archive. It was digitized from a physical copy provided by the College of Agriculture and Life Sciences at The University of Arizona. For more information about this periodical, please email CALS Publications at [email protected]
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Differences in Herbage-- Timber Relationships on Sedimentary and Igneous Soils in Arizona Ponderosa Pine Stands
This item is part of the Arizona Land and People (formerly Progressive Agriculture in Arizona) archive. It was digitized from a physical copy provided by the College of Agriculture and Life Sciences at The University of Arizona. For more information about this periodical, please email CALS Publications at [email protected]