487 research outputs found

    Deriving Hourly Evapotranspiration Rates with SEBS: A Lysimetric Evaluation

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    Numerous energy balance (EB) algorithms have been developed to use remote sensing data for mapping evapotranspiration (ET) on a regional basis. Adopting any single or combination of these models for an operational ET remote sensing program requires a thorough evaluation. The Surface Energy Balance System (SEBS) was evaluated for its ability to estimate hourly ET rates of summer tall and short crops grown in the Texas High Plains by using 15 Landsat 5 Thematic Mapper scenes acquired during 2006 to 2009. Performance of SEBS was evaluated by comparing estimated hourly ET values with measured ET data from four large weighing lysimeters, each located at the center of a 4.3 ha field in the USDA-ARS Conservation and Production Research Laboratory in Bushland, TX. The performance of SEBS in estimating hourly ET was good for crops under both irrigated and dryland conditions. A locally derived, surface albedo-based soil heat flux (G) model further improved the G estimates. Root mean square error and mean bias error were 0.11 and −0.005 mm h−1, respectively, and the Nash–Sutcliff model efficiency was 0.85 between the measured and calculated hourly ET. Considering the equal or better performance with a minimal amount of ancillary data as compared to with other EB algorithms, SEBS is a promising tool for use in an operational ET remote sensing program in the semiarid Texas High Plains. However, thorough sensitivity and error propagation analyses of input variables to quantify their impact on ET estimations for the major crops in the Texas High Plains under different agroclimatological conditions are needed before adopting the SEBS into operational ET remote sensing programs for irrigation scheduling or other purposes

    How much will precipitation increase with global warming?

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    Copyright © 2008 American Geophysical UnionThe advent of meteorological satellites during the 1970s made possible the observation of the seasonally shifting patterns of global precipitation. It was not until recently, however, that the record could be considered long enough to investigate longer-term trends and the relationship between global precipitation and global warming. Using data from the Special Sensor Microwave Imager (SSM/I) instrument, Wentz et al. [2007] reported that global mean precipitation increased at a rate of 7.4±2.6% per °C between 1987 and 2006. Meanwhile, general circulation models (GCMs) used to predict climate change simulate twentieth- and 21st-century mean precipitation increases of about 13% per °C [Held and Soden, 2006]. This difference seems surprising because some GCMs can adequately reproduce the much longer twentieth- century surface-based land-mean precipitation record [Lambert et al., 2005]. Global precipitation changes are tied to the surface energy budget through evaporation and to the tropospheric energy budget through condensation. Thus, if GCMs do underestimate global precipitation changes, the simulation of other climate variables will be affected

    Maine Blueberry Advisory Committee Research Report

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    The 1990 edition of the Maine Blueberry Advisory Committee Research Reports was prepared for the Maine Wild Blueberry Commission and the University of Maine Wild Blueberry Advisory Committee by researchers with the Maine Agricultural Experiment Station and Maine Cooperative Extension Service at the University of Maine, Orono. Projects in this report include: 1. Biology and action thresholds of secondary blueberry pests 2. Control of blueberry maggot 3. Control of secondary blueberry pests 4. Application of steam as a method of controlling secondary pest insects on lowbush blueberry: a feasibility study 5. Pollination of the lowbush blueberry by native bees 6. Nitrogen-phosphorus study 7. Potassium study 8. Multiple cropping of wild stands 9. Phosphorus dose/response curve 10. Improvement in the color and texture of the canned blueberry 11. The effect of fertilization and irrigation on blueberry fruit quality 12. Investigation of preprocess changes (chemical, microbiological, and/or physical) that could lead to the development of a simple and inexpensive method to measure preprocess berry spoilage 13. The effect of postharvest handling on the dietary fiber and ellagic acid content of lowbush blueberries 14. Determination of pesticide residue levels in freshly harvested and processed lowbush blueberries 15. Evaluation of Defoliating Diseases 16. Vacuum Sanitation for Disease Control 17. Evaluation and modification of commercial herbicide applications 18. Evaluation of the suitability of remote sensing to evaluate plant cover in lowbush blueberry fields 19. Evaluation of Sethoxydin (POAST) in lowbush blueberry fields 20. Seedling pruning study 21. Evaluation of norflurazon (SOLICAM) with or without hexazinone (VELPAR) for bunchberry control 22. Selective wiper and mechanical control of dogbane and bracken fern 23. Evaluation of norflurazon (SOLICAM) in fall vs spring for oatgrass control 24. Evaluation of sulfonyl urea herbicides for bunchberry control 25. Evaluation of postemergence applications of DPX-L5300 for bunchberry control 26. Effect of time of application and formulation of hexazinone (VELPAR) on blueberry and bunchberry 27. Investigations of lowbush blueberry fruit-bud cold hardiness 28. The economics of investing in irrigation for lowbush blueberries 29. Effects of irrigation on lowbush blueberry yield and quality 30. Groundwater and surface water development for blueberry irrigation 31. Design, fabrication and testing of an experimental sterilizer for blueberry field

    1992 Blueberry Research Progress Reports

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    The 1992 Blueberry Research Progress Reports pertain to and report on research conducted in 1991, and were prepared for the Maine Wild Blueberry Commission and the University of Maine Wild Blueberry Advisory Committee by researchers at the University of Maine, Orono. Projects in this report include: 1992 CSRS Progress Reports: 1. Investigation of Groundwater Resources 2. Sprinkler Irrigation 3. Investigation of Preprocess Changes Leading to Berry Spoilage 4. Effect of Fertilization and Irrigation on Blueberry Quality 5. Effects of Calcium Salts and Citric Acid on Quality of Canned Lowbush Blueberries 6. Pollination of Lowbush Blueberry by Native Bees 7. Application of Heat for Controlling Insects 8. Investigations of Lowbush Blueberry Fruit Bud Cold-Hardiness 9. Steam Sterilization in Lowbush Blueberry Fields 10. Heat-Tolerant Molds 11. Vacuum Sanitation for Disease Control 12. Evaluation of Infrared Burner for Weed Control 13. Evaluation and Modification of Commercial Herbicide Wipers 14. Evaluation of Remote Sensing to Estimate Plant Cover in Lowbush Blueberry Fields 15. Comparison of Three Mechanical Blueberry Harvesters vs. Hand Raking Advisory Committee Research Reports: 16. Biology and action thresholds of secondary blueberry insects 17. Control of secondary blueberry pests 18. Control of blueberry maggot 19. Effects of calcium salts and citric acid on the quality of canned lowbush blueberries 20. The effects of postharvest handling on the dietary fiber and ellagic acid content of lowbush blueberries 21. Investigation of preprocessing changes that could lead to development of simple and inexpensive method to measure preprocessing berry spoilage 22. Determination of pesticide residue levels in fresh and processed lowbush blueberries 23. Vacuum sanitation for disease control 24. Heat-tolerant molds 25. Seedling pruning study 26. Effect of time and rate of application of Clopyralid for control of Vetch in lowbush blueberries 27. Evaluation and modification of commercial herbicide wipers 28. Effect of time of application and formulation of Hexazinone (Velpar) on Blueberry and Bunchberry 29. Evaluation of postemergence applications of Tribenuron Methyl for Bunchberry control 30. Thresholds of Dogbane and Bracken Fern by mechanical and chemical control in lowbush blueberry fields 31. Evaluation of the suitability of remote sensing to evaluate plant cover in lowbush blueberry fields 32. Evalution of infrared burner for weed control 33. Effect of time of fall pruning on growth and productivity of blueberry and evaluation of infrared burner to prune blueberries 34. Effect of Boron on lowbush blueberry fruit set and yield 35. Winter injury protection by potassium 36. Multiple cropping of wild stands 37. Nitrogen-Phosphorus study 38. Phosphorus dose/response curve 39. Investigations of lowbush blueberry fruit bud cold-hardines

    Neuromuscular Electrical Stimulation as a Method to Maximize the Beneficial Effects of Muscle Stem Cells Transplanted into Dystrophic Skeletal Muscle

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    Cellular therapy is a potential approach to improve the regenerative capacity of damaged or diseased skeletal muscle. However, its clinical use has often been limited by impaired donor cell survival, proliferation and differentiation following transplantation. Additionally, functional improvements after transplantation are all-too-often negligible. Because the host microenvironment plays an important role in the fate of transplanted cells, methods to modulate the microenvironment and guide donor cell behavior are warranted. The purpose of this study was to investigate whether the use of neuromuscular electrical stimulation (NMES) for 1 or 4 weeks following muscle-derived stem cell (MDSC) transplantation into dystrophic skeletal muscle can modulate the fate of donor cells and enhance their contribution to muscle regeneration and functional improvements. Animals submitted to 4 weeks of NMES after transplantation demonstrated a 2-fold increase in the number of dystrophin+ myofibers as compared to control transplanted muscles. These findings were concomitant with an increased vascularity in the MDSC+NMES group when compared to non-stimulated counterparts. Additionally, animals subjected to NMES (with or without MDSC transplantation) presented an increased maximal specific tetanic force when compared to controls. Although cell transplantation and/or the use of NMES resulted in no changes in fatigue resistance, the combination of both MDSC transplantation and NMES resulted in a faster recovery from fatigue, when compared to non-injected and non-stimulated counterparts. We conclude that NMES is a viable method to improve MDSC engraftment, enhance dystrophic muscle strength, and, in combination with MDSC transplantation, improve recovery from fatigue. These findings suggest that NMES may be a clinically-relevant adjunct approach for cell transplantation into skeletal muscle. © 2013 Distefano et al

    Phosphoinositide-binding interface proteins involved in shaping cell membranes

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    The mechanism by which cell and cell membrane shapes are created has long been a subject of great interest. Among the phosphoinositide-binding proteins, a group of proteins that can change the shape of membranes, in addition to the phosphoinositide-binding ability, has been found. These proteins, which contain membrane-deforming domains such as the BAR, EFC/F-BAR, and the IMD/I-BAR domains, led to inward-invaginated tubes or outward protrusions of the membrane, resulting in a variety of membrane shapes. Furthermore, these proteins not only bind to phosphoinositide, but also to the N-WASP/WAVE complex and the actin polymerization machinery, which generates a driving force to shape the membranes

    Treatments targeting inotropy

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    Acute heart failure (HF) and in particular, cardiogenic shock are associated with high morbidity and mortality. A therapeutic dilemma is that the use of positive inotropic agents, such as catecholamines or phosphodiesterase-inhibitors, is associated with increased mortality. Newer drugs, such as levosimendan or omecamtiv mecarbil, target sarcomeres to improve systolic function putatively without elevating intracellular Ca2+. Although meta-analyses of smaller trials suggested that levosimendan is associated with a better outcome than dobutamine, larger comparative trials failed to confirm this observation. For omecamtiv mecarbil, Phase II clinical trials suggest a favourable haemodynamic profile in patients with acute and chronic HF, and a Phase III morbidity/mortality trial in patients with chronic HF has recently begun. Here, we review the pathophysiological basis of systolic dysfunction in patients with HF and the mechanisms through which different inotropic agents improve cardiac function. Since adenosine triphosphate and reactive oxygen species production in mitochondria are intimately linked to the processes of excitation-contraction coupling, we also discuss the impact of inotropic agents on mitochondrial bioenergetics and redox regulation. Therefore, this position paper should help identify novel targets for treatments that could not only safely improve systolic and diastolic function acutely, but potentially also myocardial structure and function over a longer-term.Peer reviewe
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