A Lagrangian snow-evolution model (SnowModel-LG) was used to produce daily, pan-Arctic, snow-on-sea-ice, snow property distributions on a 25 × 25-km grid, from 1 August 1980 through 31 July 2018 (38 years). The model was forced with NASA's Modern Era Retrospective-Analysis for Research and Applications-Version 2 (MERRA-2) and European Centre for Medium-Range Weather Forecasts (ECMWF) ReAnalysis-5th Generation (ERA5) atmospheric reanalyses, and National Snow and Ice Data Center (NSIDC) sea ice parcel concentration and trajectory data sets (approximately 61,000, 14 × 14-km parcels). The simulations performed full surface and internal energy and mass balances within a multilayer snowpack evolution system.
View Article and Find Full Text PDFJ Geophys Res Atmos
September 2013
[1] The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument was launched in October 2011 as part of the Suomi National Polar-Orbiting Partnership (S-NPP). The VIIRS instrument was designed to improve upon the capabilities of the operational Advanced Very High Resolution Radiometer and provide observation continuity with NASA's Earth Observing System's Moderate Resolution Imaging Spectroradiometer (MODIS). Since the VIIRS first-light images were received in November 2011, NASA- and NOAA-funded scientists have been working to evaluate the instrument performance and generate land and cryosphere products to meet the needs of the NOAA operational users and the NASA science community.
View Article and Find Full Text PDFUncertainty in future water supplies for the Phoenix Metropolitan Area (Phoenix) are exacerbated by the near certainty of increased, future water demands; water demand may increase eightfold or more by 2030 for some communities. We developed a provider-based water management and planning model for Phoenix termed WaterSim 4.0.
View Article and Find Full Text PDFThe recommended dose (bolus 0.4 mg/kg followed by 0.15 mg/kg per hour) of lepirudin, a direct thrombin inhibitor licensed for treatment of heparin-induced thrombocytopenia (HIT), is too high.
View Article and Find Full Text PDFA two-year-old female alpaca suddenly became lame on its right hindlimb. Eight days later clinical and radiographic examinations showed that the patella had become temporarily fixed within the supratrochlear notch of the femur. Under general anaesthesia an abrasion trochleoplasty followed by fascial imbrication was carried out.
View Article and Find Full Text PDFGraefes Arch Clin Exp Ophthalmol
May 2000
Background: In the kidney, the trachea, and the colon, nitric oxide (NO) can modulate transepithelial fluid transport. This study investigates whether isolated human and porcine ciliary processes produce NO.
Methods: Porcine ciliary processes and iris were used either fresh or thawed after storage at -70 degrees C.
Background: NO regulates vascular tone and structure, platelets, and monocytes. NO is synthesized by endothelial NO synthase (eNOS). Endothelial dysfunction occurs in atherosclerosis.
View Article and Find Full Text PDFDue to its strategic anatomical position, the endothelium is constantly exposed to the different risk factors for atherosclerosis. During the last decade it has become clear that hypertension profoundly affects endothelial function. Depending on the form of hypertension, endothelium-dependent relaxation is impaired in most vascular beds.
View Article and Find Full Text PDFAtherosclerosis and its consequences account for most of the morbidity and mortality in Western countries. It is a disease of the intima and primarily involves four cell types, i.e.
View Article and Find Full Text PDFWe investigated vascular function in mouse Ren-2 transgenic rats with hypertension. Mesenteric resistance arteries of transgenic and Sprague-Dawley rats (controls) were isolated at ages 6 and 12 wk and suspended in myographs for isometric tension recording. Systolic blood pressure was higher in transgenic than control rats (P < 0.
View Article and Find Full Text PDFAging is an important determinant of vascular disease. Endothelium-derived nitric oxide (NO) is protective as a vasodilator and inhibitor of platelet function. This study was designed to directly measure effects of prolonged aging on endotheliai NO release in isolated blood vessels and to delineate differences between the systemic and pulmonary circulation.
View Article and Find Full Text PDFThe endothelium takes part in the regulation of vascular tone through the production of endothelium-derived relaxing and contracting factors. The L-arginine pathway within endothelial cells in the blood vessel wall is the source of production of the endogenous nitrovasodilator, nitric oxide (NO). The NO molecule has one unpaired electron and readily reacts with oxygen, superoxide radicals, or transition metals.
View Article and Find Full Text PDFThe endothelium plays a critical role in maintaining vascular tone by releasing vasoconstrictor and vasodilator substances. Endothelium-derived nitric oxide is a vasodilator that can be rapidly inactivated by superoxide (reaction rate constant, K = 3.6 x 10(9) L/mol per second).
View Article and Find Full Text PDFJ Cardiovasc Pharmacol
August 1995
The efficacy of vasodilation depends on the drug and the contractile agonist involved. Furthermore, vasodilation also may be detrimental (i.e.
View Article and Find Full Text PDFBackground: Endothelium-derived substances and the renin-angiotensin system are important regulators of vascular tone. This study was designed to evaluate the effects of age and hypertension on vascular function of rat coronary arteries.
Methods And Results: Rings of the left anterior descending coronary artery were isolated from Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR) at 12 (younger) and 72 (older) weeks of age and suspended in myographs (37 degrees C, 95% O2/5% CO2) for isometric tension recording.
Endothelin-1 (ET-1) and angiotensin II (AII) are potent vasoconstrictor hormones which regulate tissue perfusion and blood pressure. We pharmacologically characterized endothelin and angiotensin receptors mediating contractions of human mammary resistance arteries in myographs for isometric tension recording. ET-1 caused potent contractions.
View Article and Find Full Text PDFSchweiz Rundsch Med Prax
September 1994
Background: The renin-angiotensin system and endothelium-derived nitric oxide (EDNO) are important regulators of vascular tone. This study was designed to investigate endothelial and vascular smooth muscle function in coronary arteries of Ren-2 transgenic rats.
Methods And Results: Left anterior descending coronary arteries and aortas were isolated from transgenic rats and Sprague-Dawley control rats at 6 (young) and 12 (adult) weeks of age and examined in myographs or organ chambers for isometric tension recording.
J Cardiovasc Pharmacol
June 1994
Neurohumoral changes influencing peripheral vascular resistance play a major role in congestive heart failure (CHF). We studied vascular function in 1-year-old cardiomyopathic syrian hamsters with pulmonary congestion and age-matched control hamsters. Aorta and mesenteric resistance arteries were suspended in organ chambers and myographs, respectively, for isometric tension recording.
View Article and Find Full Text PDFBackground: Coronary artery disease is an important complication of hypertension. Therefore, the effects of antihypertensive therapy on the endothelial nitric oxide (NO)/L-arginine pathway and vascular smooth muscle were studied in left anterior descending coronary arteries of Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR). Angiotensin II (AT1) receptor antagonists CGP 48369 and valsartan, angiotensin-converting enzyme inhibitor benazepril HCl, and calcium antagonist nifedipine were used as antihypertensive agents.
View Article and Find Full Text PDFThe endothelium is a physical barrier between the blood and vascular smooth muscle, a source of enzymes activating and deactivating cardiovascular hormones and a site of production of relaxing and contracting factors. In addition, the endothelium is a source of growth inhibitors and promoters of vascular smooth muscle cells. Monoaminooxidase deactivates catecholamines and serotonin.
View Article and Find Full Text PDFJ Cardiovasc Pharmacol
October 1992
Small arteries with a diameter of 200 microns or less play an important role in the regulation of peripheral vascular resistance. Dysregulation of vascular tone of these arteries may contribute significantly to high blood pressure. The contractile state of blood vessels is regulated by peripheral neurons, vascular smooth muscle, and the endothelium.
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