5 research outputs found
Estimating Groundwater Evapotranspiration for Tamarisk-Dominated Riparian Communities through Satellite Imaging, Virgin and Muddy Rivers, Nevada
Southern Nevada features very high water demands and very low water
availability. Tamarisk is a significant user of surface and groundwater supplies but uses
significantly less water when it is defoliated by the northern tamarisk beetle. Because the
ability to account for the water conserved by tamarisk defoliation would be helpful to
water managers, I attempted to measure the difference in evapotranspiration rates before
and after defoliation using remote sensing. Estimations of annual groundwater
evapotranspiration rates were made using remote-sensing data from the Landsat 5
satellite for the Virgin and Muddy River systems in Southern Nevada for the years of
2007 through 2011 at various points in the northern tamarisk beetle’s diapause cycle.
Comparisons were then made between the evapotranspiration rates of tamarisk groves
that had or had not been defoliated to estimate the water total water saved. Results
suggest that for the year 2011, the reduced transpiration rate of tamarisk due to
defoliation saved an estimated 2,205 ac-ft of water
OpenET : filling a critical data gap in water management for the western United States.
The lack of consistent, accurate information on evapotranspiration (ET) and consumptive use of water by irrigated agriculture is one of the most important data gaps for water managers in the western United States (U.S.) and other arid agricultural regions globally. The ability to easily access information on ET is central to improving water budgets across the West, advancing the use of data-driven irrigation management strategies, and expanding incentive-driven conservation programs. Recent advances in remote sensing of ET have led to the development of multiple approaches for field-scale ET mapping that have been used for local and regional water resource management applications by U.S. state and federal agencies. The OpenET project is a community-driven effort that is building upon these advances to develop an operational system for generating and distributing ET data at a field scale using an ensemble of six well-established satellite-based approaches for mapping ET. Key objectives of OpenET include: Increasing access to remotely sensed ET data through a web-based data explorer and data services; supporting the use of ET data for a range of water resource management applications; and development of use cases and training resources for agricultural producers and water resource managers. Here we describe the OpenET framework, including the models used in the ensemble, the satellite, meteorological, and ancillary data inputs to the system, and the OpenET data visualization and access tools. We also summarize an extensive intercomparison and accuracy assessment conducted using ground measurements of ET from 139 flux tower sites instrumented with open path eddy covariance systems. Results calculated for 24 cropland sites from Phase I of the intercomparison and accuracy assessment demonstrate strong agreement between the satellite-driven ET models and the flux tower ET data. For the six models that have been evaluated to date (ALEXI/DisALEXI, eeMETRIC, geeSEBAL, PT-JPL, SIMS, and SSEBop) and the ensemble mean, the weighted average mean absolute error (MAE) values across all sites range from 13.6 to 21.6 mm/month at a monthly timestep, and 0.74 to 1.07 mm/day at a daily timestep. At seasonal time scales, for all but one of the models the weighted mean total ET is within ±8% of both the ensemble mean and the weighted mean total ET calculated from the flux tower data. Overall, the ensemble mean performs as well as any individual model across nearly all accuracy statistics for croplands, though some individual models may perform better for specific sites and regions. We conclude with three brief use cases to illustrate current applications and benefits of increased access to ET data, and discuss key lessons learned from the development of OpenET
Inhibition of phosphodiesterase type 9 reduces obesity and cardiometabolic syndrome in mice
Central obesity with cardiometabolic syndrome (CMS) is a major global contributor to human disease, and effective therapies are needed. Here, we show that cyclic GMP-selective phosphodiesterase 9A inhibition (PDE9-I) in both male and ovariectomized female mice suppresses preestablished severe diet-induced obesity/CMS with or without superimposed mild cardiac pressure load. PDE9-I reduces total body, inguinal, hepatic, and myocardial fat; stimulates mitochondrial activity in brown and white fat; and improves CMS, without significantly altering activity or food intake. PDE9 localized at mitochondria, and its inhibition in vitro stimulated lipolysis in a PPARα-dependent manner and increased mitochondrial respiration in both adipocytes and myocytes. PPARα upregulation was required to achieve the lipolytic, antiobesity, and metabolic effects of PDE9-I. All these PDE9-I-induced changes were not observed in obese/CMS nonovariectomized females, indicating a strong sexual dimorphism. We found that PPARα chromatin binding was reoriented away from fat metabolism-regulating genes when stimulated in the presence of coactivated estrogen receptor-α, and this may underlie the dimorphism. These findings have translational relevance given that PDE9-I is already being studied in humans for indications including heart failure, and efficacy against obesity/CMS would enhance its therapeutic utility
CHIP phosphorylation by protein kinase G enhances protein quality control and attenuates cardiac ischemic injury
Carboxyl terminus of Hsc70-interacting protein (CHIP) is proteostasis regulator. Here the authors show that CHIP-mediated protein turnover is enhanced by PKG-mediated phosphorylation, which results in attenuated cardiac ischemic proteotoxicity